@book{Windham-Myers2018,
address = {Boca Raton, FL, USA},
doi = {10.1201/9780429435362},
editor = {Windham-Myers, L. and Crooks, S. and Troxler, T.},
isbn = {9780429435362},
pages = {507},
publisher = {CRC Press},
title = {{A Blue Carbon Primer: The State of Coastal Wetland Carbon Science, Practice and Policy}},
year = {2018}
}
@article{Łukawska-Matuszewska2019,
abstract = {Deterioration of oxygen conditions in water below the halocline has been observed in the Baltic Sea. Deoxygenation is linked to the reduced frequency and volume of inflows of highly saline surface water from the North Sea (major Baltic inflows---MBIs) in the second half of the twentieth century and the increased organic matter respiration due to eutrophication. In the present study, the impact of worsening oxygen conditions on pyrite content in the Gda{\'{n}}sk Deep (max. depth of 118 m, southern Baltic Sea) sediments was determined. Geochemical parameters (acid volatile sulfides, pyrite sulfur, reactive iron, organic carbon, sedimentation rate and sediment age) were analyzed in relation to the variation in bottom water oxygen concentration and the occurrence of MBI. The obtained results demonstrate that pyrite content in the study area decreased after 1960. The declining pyrite content coincided with the deterioration of oxygen conditions (concentration{\{}$\backslash$thinspace{\}}{\textless}{\{}$\backslash$thinspace{\}}2 ml l−1) in bottom water. In the same period, reactive iron concentration decreased and organic carbon increased in sediment. In the period 1616--1960, average pyrite accumulation rate was 322 {\{}$\backslash$textmu{\}}mol m−2 day−1. In the subsequent years, its average accumulation rate decreased to 210 {\{}$\backslash$textmu{\}}mol m−2 day−1. Fluctuations of oxygenation of bottom water in the study area were manifested by highly variable degree of pyritization (36{\{}$\backslash$thinspace{\}}{\{}$\backslash$textpm{\}}{\{}$\backslash$thinspace{\}}11{\%}) and particulate organic carbon to pyrite sulfur ratio (2.8--37).},
author = {{\L}ukawska-Matuszewska, Katarzyna and Graca, Bo{\.{z}}ena and Broc{\l}awik, Olga and Zalewska, Tamara},
doi = {10.1007/s10533-018-0530-2},
issn = {0168-2563},
journal = {Biogeochemistry},
month = {jan},
number = {2},
pages = {209--230},
title = {{The impact of declining oxygen conditions on pyrite accumulation in shelf sediments (Baltic Sea)}},
url = {https://doi.org/10.1007/s10533-018-0530-2 http://link.springer.com/10.1007/s10533-018-0530-2},
volume = {142},
year = {2019}
}
@article{Abatzoglou2019,
abstract = {Abstract Changes in global fire activity are influenced by a multitude of factors including land-cover change, policies, and climatic conditions. This study uses 17 climate models to evaluate when changes in fire weather, as realized through the Fire Weather Index, emerge from the expected range of internal variability due to anthropogenic climate change using the time of emergence framework. Anthropogenic increases in extreme Fire Weather Index days emerge for 22{\%} of burnable land area globally by 2019, including much of the Mediterranean and the Amazon. By the midtwenty-first century, emergence among the different Fire Weather Index metrics occurs for 33?62{\%} of burnable lands. Emergence of heightened fire weather becomes more widespread as a function of global temperature change. At 2 °C above preindustrial levels, the area of emergence is half that for 3 °C. These results highlight increases in fire weather conditions with human-caused climate change and incentivize local adaptation efforts to limit detrimental fire impacts.},
author = {Abatzoglou, John T. and Williams, A. Park and Barbero, Renaud},
doi = {10.1029/2018GL080959},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {climate change,climate modeling,fire,natural variability},
month = {jan},
number = {1},
pages = {326--336},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Global Emergence of Anthropogenic Climate Change in Fire Weather Indices}},
url = {https://doi.org/10.1029/2018GL080959},
volume = {46},
year = {2019}
}
@article{doi:10.1111/gcb.13069,
abstract = {Abstract Release of greenhouse gases from thawing permafrost is potentially the largest terrestrial feedback to climate change and one of the most likely to occur; however, estimates of its strength vary by a factor of thirty. Some of this uncertainty stems from abrupt thaw processes known as thermokarst (permafrost collapse due to ground ice melt), which alter controls on carbon and nitrogen cycling and expose organic matter from meters below the surface. Thermokarst may affect 20–50{\%} of tundra uplands by the end of the century; however, little is known about the effect of different thermokarst morphologies on carbon and nitrogen release. We measured soil organic matter displacement, ecosystem respiration, and soil gas concentrations at 26 upland thermokarst features on the North Slope of Alaska. Features included the three most common upland thermokarst morphologies: active-layer detachment slides, thermo-erosion gullies, and retrogressive thaw slumps. We found that thermokarst morphology interacted with landscape parameters to determine both the initial displacement of organic matter and subsequent carbon and nitrogen cycling. The large proportion of ecosystem carbon exported off-site by slumps and slides resulted in decreased ecosystem respiration postfailure, while gullies removed a smaller portion of ecosystem carbon but strongly increased respiration and N2O concentration. Elevated N2O in gully soils persisted through most of the growing season, indicating sustained nitrification and denitrification in disturbed soils, representing a potential noncarbon permafrost climate feedback. While upland thermokarst formation did not substantially alter redox conditions within features, it redistributed organic matter into both oxic and anoxic environments. Across morphologies, residual organic matter cover, and predisturbance respiration explained 83{\%} of the variation in respiration response. Consistent differences between upland thermokarst types may contribute to the incorporation of this nonlinear process into projections of carbon and nitrogen release from degrading permafrost.},
author = {Abbott, Benjamin W and Jones, Jeremy B},
doi = {10.1111/gcb.13069},
journal = {Global Change Biology},
keywords = {CH4,N2O,active-layer detachment slide,ecosystem respiration,permafrost,permafrost carbon feedback,thaw slump,thermo-erosion gully,thermokarst,tundra},
number = {12},
pages = {4570--4587},
title = {{Permafrost collapse alters soil carbon stocks, respiration, CH4, and N2O in upland tundra}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13069},
volume = {21},
year = {2015}
}
@article{Abram2021,
abstract = {The 2019/20 Black Summer bushfire disaster in southeast Australia was unprecedented: the extensive area of forest burnt, the radiative power of the fires, and the extraordinary number of fires that developed into extreme pyroconvective events were all unmatched in the historical record. Australia's hottest and driest year on record, 2019, was characterised by exceptionally dry fuel loads that primed the landscape to burn when exposed to dangerous fire weather and ignition. The combination of climate variability and long-term climate trends generated the climate extremes experienced in 2019, and the compounding effects of two or more modes of climate variability in their fire-promoting phases (as occurred in 2019) has historically increased the chances of large forest fires occurring in southeast Australia. Palaeoclimate evidence also demonstrates that fire-promoting phases of tropical Pacific and Indian ocean variability are now unusually frequent compared with natural variability in pre-industrial times. Indicators of forest fire danger in southeast Australia have already emerged outside of the range of historical experience, suggesting that projections made more than a decade ago that increases in climate-driven fire risk would be detectable by 2020, have indeed eventuated. The multiple climate change contributors to fire risk in southeast Australia, as well as the observed non-linear escalation of fire extent and intensity, raise the likelihood that fire events may continue to rapidly intensify in the future. Improving local and national adaptation measures while also pursuing ambitious global climate change mitigation efforts would provide the best strategy for limiting further increases in fire risk in southeast Australia.},
author = {Abram, Nerilie J. and Henley, Benjamin J. and {Sen Gupta}, Alex and Lippmann, Tanya J. R. and Clarke, Hamish and Dowdy, Andrew J. and Sharples, Jason J. and Nolan, Rachael H. and Zhang, Tianran and Wooster, Martin J. and Wurtzel, Jennifer B. and Meissner, Katrin J. and Pitman, Andrew J. and Ukkola, Anna M. and Murphy, Brett P. and Tapper, Nigel J. and Boer, Matthias M.},
doi = {10.1038/s43247-020-00065-8},
issn = {2662-4435},
journal = {Communications Earth {\&} Environment},
month = {dec},
number = {1},
pages = {8},
title = {{Connections of climate change and variability to large and extreme forest fires in southeast Australia}},
url = {http://www.nature.com/articles/s43247-020-00065-8},
volume = {2},
year = {2021}
}
@article{Achat2016,
abstract = {Climate change has consequences for terrestrial functioning, but predictions of plant responses remain uncertain because of the gaps in the representation of nutrient cycles and C--N--P interactions in ecosystem models. Here, we review the processes that are included in ecosystem models, but focus on coupled C--N--P cycle models. We highlight important plant adjustments to climate change, elevated atmospheric CO2, and/or nutrient limitations that are currently not---or only partially---incorporated in ecosystem models by reviewing experimental studies and compiling data. Plant adjustments concern C:N:P stoichiometry, photosynthetic capacity, nutrient resorption rates, allocation patterns, symbiotic N2 fixation and root exudation (phosphatases, carboxylates) and the effect of root exudation on nutrient mobilization in the soil rhizosphere (P solubilization, biochemical mineralization of organic P and priming effect). We showed that several plant adjustments could be formulated and calibrated using existing experimental data in the literature. Finally, we proposed a roadmap for future research because improving ecosystem models necessitate specific data and collaborations between modelers and empiricists.},
annote = {added by A.Eliseev 22.01.2019},
author = {Achat, David L and Augusto, Laurent and Gallet-Budynek, Anne and Loustau, Denis},
doi = {10.1007/s10533-016-0274-9},
issn = {0168-2563},
journal = {Biogeochemistry},
month = {dec},
number = {1-2},
pages = {173--202},
title = {{Future challenges in coupled C–N–P cycle models for terrestrial ecosystems under global change: a review}},
url = {https://doi.org/10.1007/s10533-016-0274-9 http://link.springer.com/10.1007/s10533-016-0274-9},
volume = {131},
year = {2016}
}
@article{Adams2012,
author = {Adams, C.A. and Andrews, J.E. and Jickells, T.},
doi = {10.1016/j.scitotenv.2011.11.058},
issn = {00489697},
journal = {Science of The Total Environment},
month = {sep},
pages = {240--251},
title = {{Nitrous oxide and methane fluxes vs. carbon, nitrogen and phosphorous burial in new intertidal and saltmarsh sediments}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0048969711013738},
volume = {434},
year = {2012}
}
@article{Adams2020,
abstract = {There is broad consensus that, via changes in stomatal conductance, plants moderate the exchanges of water and carbon between the biosphere and atmosphere, playing a major role in global hydroclimate. Tree rings record atmospheric CO2 concentration (ca) and its isotopic composition (13C/12C)—mediated by stomatal and photosynthetic influences—that can be expressed in terms of intrinsic water-use efficiency (W). Here, we compile a global W dataset based on 422 tree-ring isotope series and report that W increased with ca over the twentieth century, but the rates of increase (dW/dca) declined by half. Angiosperms contributed more than gymnosperms to the slowdown, and in recent decades, dW/dca for angiosperms was close to zero. dW/dca varies widely across climatic regions and reflects pauses in emissions during the Great Depression and after World War II. There is strong spatial variability in climate forcing via an increasing W, which is weakening globally with time.},
author = {Adams, Mark A. and Buckley, Thomas N. and Turnbull, Tarryn L.},
doi = {10.1038/s41558-020-0747-7},
isbn = {4155802007477},
issn = {17586798},
journal = {Nature Climate Change},
number = {5},
pages = {466--471},
publisher = {Springer US},
title = {{Diminishing CO2-driven gains in water-use efficiency of global forests}},
url = {http://dx.doi.org/10.1038/s41558-020-0747-7},
volume = {10},
year = {2020}
}
@article{Ahlstrom2015a,
abstract = {The growth rate of atmospheric carbon dioxide (CO2) concentrations since industrialization is characterized by large interannual variability, mostly resulting from variability in CO2 uptake by terrestrial ecosystems (typically termed carbon sink). However, the contributions of regional ecosystems to that variability are not well known. Using an ensemble of ecosystem and land-surface models and an empirical observation-based product of global gross primary production, we show that the mean sink, trend, and interannual variability in CO2 uptake by terrestrial ecosystems are dominated by distinct biogeographic regions. Whereas the mean sink is dominated by highly productive lands (mainly tropical forests), the trend and interannual variability of the sink are dominated by semi-arid ecosystems whose carbon balance is strongly associated with circulation-driven variations in both precipitation and temperature.},
author = {Ahlstrom, A. and Raupach, Michael R. and Schurgers, Guy and Smith, Benjamin and Arneth, Almut and Jung, Martin and Reichstein, Markus and Canadell, Josep G. and Friedlingstein, Pierre and Jain, Atul K. and Kato, Etsushi and Poulter, Benjamin and Sitch, Stephen and Stocker, Benjamin D. and Viovy, Nicolas and Wang, Ying Ping and Wiltshire, Andy and Zaehle, S{\"{o}}nke and Zeng, Ning},
doi = {10.1126/science.aaa1668},
isbn = {1223326500},
issn = {0036-8075},
journal = {Science},
month = {may},
number = {6237},
pages = {895--899},
pmid = {25999504},
title = {{The dominant role of semi-arid ecosystems in the trend and variability of the land CO2 sink}},
url = {http://science.sciencemag.org/content/348/6237/895 http://www.sciencemag.org/cgi/doi/10.1126/science.aaa1668},
volume = {348},
year = {2015}
}
@article{Ahn2014,
annote = {added by A.Eliseev 25.01.2019},
author = {Ahn, Jinho and Brook, Edward J},
doi = {10.1038/ncomms4723},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {3723},
publisher = {The Author(s)},
title = {{Siple Dome ice reveals two modes of millennial CO2 change during the last ice age}},
url = {https://doi.org/10.1038/ncomms4723 http://10.0.4.14/ncomms4723 https://www.nature.com/articles/ncomms4723{\#}supplementary-information http://www.nature.com/articles/ncomms4723},
volume = {5},
year = {2014}
}
@article{Ainsworth2005,
abstract = {Free-air CO(2) enrichment (FACE) experiments allow study of the effects of elevated [CO(2)] on plants and ecosystems grown under natural conditions without enclosure. Data from 120 primary, peer-reviewed articles describing physiology and production in the 12 large-scale FACE experiments (475-600 ppm) were collected and summarized using meta-analytic techniques. The results confirm some results from previous chamber experiments: light-saturated carbon uptake, diurnal C assimilation, growth and above-ground production increased, while specific leaf area and stomatal conductance decreased in elevated [CO(2)]. There were differences in FACE. Trees were more responsive than herbaceous species to elevated [CO(2)]. Grain crop yields increased far less than anticipated from prior enclosure studies. The broad direction of change in photosynthesis and production in elevated [CO(2)] may be similar in FACE and enclosure studies, but there are major quantitative differences: trees were more responsive than other functional types; C(4) species showed little response; and the reduction in plant nitrogen was small and largely accounted for by decreased Rubisco. The results from this review may provide the most plausible estimates of how plants in their native environments and field-grown crops will respond to rising atmospheric [CO(2)]; but even with FACE there are limitations, which are also discussed.},
author = {Ainsworth, Elizabeth A. and Long, Stephen P.},
doi = {10.1111/j.1469-8137.2004.01224.x},
isbn = {1469-8137},
issn = {0028646X},
journal = {New Phytologist},
keywords = {Atmospheric change,Crop yield,Elevated [CO2],FACE (free air CO2enrichment),Leaf area,Photosynthesis,Rubisco},
number = {2},
pages = {351--372},
pmid = {15720649},
title = {{What have we learned from 15 years of free-air CO2 enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy properties and plant production to rising CO2}},
volume = {165},
year = {2005}
}
@article{Ajayi2020,
author = {Ajayi, Seyi and Kump, Lee R. and Ridgwell, Andy and {Kirtland Turner}, Sandra and Hay, Carling C. and Bralower, Timothy J.},
doi = {10.1029/2019GC008620},
issn = {1525-2027},
journal = {Geochemistry, Geophysics, Geosystems},
month = {mar},
number = {3},
pages = {e2019GC008620},
title = {{Evaluation of Paleocene–Eocene Thermal Maximum Carbon Isotope Record Completeness – An Illustration of the Potential of Dynamic Time Warping in Aligning Paleo-Proxy Records}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GC008620},
volume = {21},
year = {2020}
}
@article{Alleneaat0636,
abstract = {The turbulent surfaces of rivers and streams are natural hotspots of biogeochemical exchange with the atmosphere. At the global scale, the total river-atmosphere flux of trace gasses such as CO2 depends on the proportion of Earth{\{}$\backslash$textquoteright{\}}s surface that is covered by the fluvial network, yet the total surface area of rivers and streams is poorly constrained. We used a global database of planform river hydromorphology and a statistical approach to show that global river and stream surface area at mean annual discharge is 773,000 {\{}$\backslash$textpm{\}} 79,000 km2 (0.58 {\{}$\backslash$textpm{\}} 0.06{\%}) of Earth{\{}$\backslash$textquoteright{\}}s non-glaciated land surface, an area 44 {\{}$\backslash$textpm{\}} 15{\%} larger than previous spatial estimates. We found that rivers and streams likely play a greater role in controlling land-atmosphere fluxes than currently represented in global carbon budgets.},
author = {Allen, George H and Pavelsky, Tamlin M},
doi = {10.1126/science.aat0636},
issn = {0036-8075},
journal = {Science},
month = {aug},
number = {6402},
pages = {585--588},
publisher = {American Association for the Advancement of Science},
title = {{Global extent of rivers and streams}},
url = {http://science.sciencemag.org/content/early/2018/06/27/science.aat0636 http://www.sciencemag.org/lookup/doi/10.1126/science.aat0636},
volume = {361},
year = {2018}
}
@incollection{IPCC2018,
author = {Allen, M.R. and Dube, O.P. and Solecki, W. and Arag{\'{o}}n-Durand, F. and Cramer, W. and Humphreys, S. and Kainuma, M. and Kala, J. and Mahowald, N. and Mulugetta, Y. and Perez, R. and Wairiu, M. and Zickfeld, K.},
booktitle = {Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change,},
chapter = {1},
editor = {Masson-Delmotte, V. and Zhai, P. and P{\"{o}}rtner, H.-O. and Roberts, D. and Skea, J. and Shukla, P.R. and Pirani, A. and Moufouma-Okia, W. and P{\'{e}}an, C. and Pidcock, R. and Connors, S. and Matthews, J.B.R. and Chen, Y. and Zhou, X. and Gomis, M.I. and Lonnoy, E. and Maycock, T. and Tignor, M. and Waterfield, T.},
pages = {49--92},
publisher = {In Press},
title = {{Framing and Context}},
url = {https://www.ipcc.ch/sr15/chapter/chapter-1},
year = {2018}
}
@article{doi:10.1890/ES15-00203.1,
abstract = {Patterns, mechanisms, projections, and consequences of tree mortality and associated broad-scale forest die-off due to drought accompanied by warmer temperatures—“hotter drought”, an emerging characteristic of the Anthropocene—are the focus of rapidly expanding literature. Despite recent observational, experimental, and modeling studies suggesting increased vulnerability of trees to hotter drought and associated pests and pathogens, substantial debate remains among research, management and policy-making communities regarding future tree mortality risks. We summarize key mortality-relevant findings, differentiating between those implying lesser versus greater levels of vulnerability. Evidence suggesting lesser vulnerability includes forest benefits of elevated [CO2] and increased water-use efficiency; observed and modeled increases in forest growth and canopy greening; widespread increases in woody-plant biomass, density, and extent; compensatory physiological, morphological, and genetic mechanisms; dampening ecological feedbacks; and potential mitigation by forest management. In contrast, recent studies document more rapid mortality under hotter drought due to negative tree physiological responses and accelerated biotic attacks. Additional evidence suggesting greater vulnerability includes rising background mortality rates; projected increases in drought frequency, intensity, and duration; limitations of vegetation models such as inadequately represented mortality processes; warming feedbacks from die-off; and wildfire synergies. Grouping these findings we identify ten contrasting perspectives that shape the vulnerability debate but have not been discussed collectively. We also present a set of global vulnerability drivers that are known with high confidence: (1) droughts eventually occur everywhere; (2) warming produces hotter droughts; (3) atmospheric moisture demand increases nonlinearly with temperature during drought; (4) mortality can occur faster in hotter drought, consistent with fundamental physiology; (5) shorter droughts occur more frequently than longer droughts and can become lethal under warming, increasing the frequency of lethal drought nonlinearly; and (6) mortality happens rapidly relative to growth intervals needed for forest recovery. These high-confidence drivers, in concert with research supporting greater vulnerability perspectives, support an overall viewpoint of greater forest vulnerability globally. We surmise that mortality vulnerability is being discounted in part due to difficulties in predicting threshold responses to extreme climate events. Given the profound ecological and societal implications of underestimating global vulnerability to hotter drought, we highlight urgent challenges for research, management, and policy-making communities.},
author = {Allen, Craig D and Breshears, David D and McDowell, Nate G},
doi = {10.1890/ES15-00203.1},
journal = {Ecosphere},
keywords = {CO2 fertilization,ESA Centennial Paper,carbon starvation,climate change,drought,extreme events,forest die-off,forests,hydraulic failure,insect pests,pathogens,tree mortality,woodlands},
number = {8},
pages = {art129},
title = {{On underestimation of global vulnerability to tree mortality and forest die-off from hotter drought in the Anthropocene}},
url = {https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/ES15-00203.1},
volume = {6},
year = {2015}
}
@article{Allen2009,
abstract = {The effect of a cumulative emission of carbon on peak global mean surface temperature is better constrained than the effect of stabilizing the atmospheric composition. The approach is also insensitive to the timing or peak rate of emissions. Using carbon cycle models, it is shown that a trillion tonnes of carbon emissions (about half of which has already been emitted since industrialization began) will produce a most likely peak warming of 2 degrees Celsius.},
author = {Allen, Myles R. and Frame, David J. and Huntingford, Chris and Jones, Chris D. and Lowe, Jason A. and Meinshausen, Malte and Meinshausen, Nicolai},
doi = {10.1038/nature08019},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7242},
pages = {1163--1166},
publisher = {Nature Publishing Group},
title = {{Warming caused by cumulative carbon emissions towards the trillionth tonne}},
url = {http://www.nature.com/articles/nature08019},
volume = {458},
year = {2009}
}
@article{AlHaj2020,
author = {Al‐Haj, Alia N. and Fulweiler, Robinson W.},
doi = {10.1111/gcb.15046},
issn = {1354-1013},
journal = {Global Change Biology},
month = {may},
number = {5},
pages = {2988--3005},
title = {{A synthesis of methane emissions from shallow vegetated coastal ecosystems}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.15046},
volume = {26},
year = {2020}
}
@article{Anagnostou2016a,
author = {Anagnostou, Eleni and John, Eleanor H. and Edgar, Kirsty M. and Foster, Gavin L. and Ridgwell, Andy and Inglis, Gordon N. and Pancost, Richard D. and Lunt, Daniel J. and Pearson, Paul N.},
doi = {10.1038/nature17423},
issn = {0028-0836},
journal = {Nature},
month = {may},
number = {7603},
pages = {380--384},
publisher = {Nature Publishing Group},
title = {{Changing atmospheric CO2 concentration was the primary driver of early Cenozoic climate}},
url = {http://dx.doi.org/10.1038/nature17423 http://www.nature.com/articles/nature17423},
volume = {533},
year = {2016}
}
@article{Anagnostou2020,
abstract = {Despite recent advances, the link between the evolution of atmospheric CO 2 and climate during the Eocene greenhouse remains uncertain. In particular, modelling studies suggest that in order to achieve the global warmth that characterised the early Eocene, warmer climates must be more sensitive to CO 2 forcing than colder climates. Here, we test this assertion in the geological record by combining a new high-resolution boron isotope-based CO 2 record with novel estimates of Global Mean Temperature. We find that Equilibrium Climate Sensitivity (ECS) was indeed higher during the warmest intervals of the Eocene, agreeing well with recent model simulations, and declined through the Eocene as global climate cooled. These observations indicate that the canonical IPCC range of ECS (1.5 to 4.5 °C per doubling) is unlikely to be appropriate for high-CO 2 warm climates of the past, and the state dependency of ECS may play an increasingly important role in determining the state of future climate as the Earth continues to warm.},
author = {Anagnostou, E. and John, E. H. and Babila, T. L. and Sexton, P. F. and Ridgwell, A. and Lunt, D. J. and Pearson, P. N. and Chalk, T. B. and Pancost, R. D. and Foster, G. L.},
doi = {10.1038/s41467-020-17887-x},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {4436},
title = {{Proxy evidence for state-dependence of climate sensitivity in the Eocene greenhouse}},
url = {http://www.nature.com/articles/s41467-020-17887-x},
volume = {11},
year = {2020}
}
@article{Anav2013a,
abstract = {The authors assess the ability of 18 Earth system models to simulate the land and ocean carbon cycle for the present climate. These models will be used in the next Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) for climate projections, and such evaluation allows identification of the strengths and weaknesses of individual coupled carbon–climate models as well as identification of systematic biases of the models. Results show that models correctly reproduce the main climatic variables controlling the spatial and temporal characteristics of the carbon cycle. The seasonal evolution of the variables under examination is well captured. However, weaknesses appear when reproducing specific fields: in particular, considering the land carbon cycle, a general overestimation of photosynthesis and leaf area index is found for most of the models, while the ocean evaluation shows that quite a few models underestimate the primary production.The authors also propose climate and carbon cycle performance metrics in order to assess whether there is a set of consistently better models for reproducing the carbon cycle. Averaged seasonal cycles and probability density functions (PDFs) calculated from model simulations are compared with the corresponding seasonal cycles and PDFs from different observed datasets. Although the metrics used in this study allow identification of some models as better or worse than the average, the ranking of this study is partially subjective because of the choice of the variables under examination and also can be sensitive to the choice of reference data. In addition, it was found that the model performances show significant regional variations.},
annote = {doi: 10.1175/JCLI-D-12-00417.1},
author = {Anav, A and Friedlingstein, P and Kidston, M and Bopp, L and Ciais, P and Cox, P and Jones, C and Jung, M and Myneni, R and Zhu, Z},
doi = {10.1175/JCLI-D-12-00417.1},
isbn = {0894-8755},
issn = {0894-8755},
journal = {Journal of Climate},
month = {sep},
number = {18},
pages = {6801--6843},
publisher = {American Meteorological Society},
title = {{Evaluating the Land and Ocean Components of the Global Carbon Cycle in the CMIP5 Earth System Models}},
url = {http://dx.doi.org/10.1175/JCLI-D-12-00417.1 http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00417.1},
volume = {26},
year = {2013}
}
@article{Anav2015a,
abstract = {Great advances have been made in the last decade in quantifying and understanding the spatiotemporal patterns of terrestrial gross primary production (GPP) with ground, atmospheric, and space observations. However, although global GPP estimates exist, each data set relies upon assumptions and none of the available data are based only on measurements. Consequently, there is no consensus on the global total GPP and large uncertainties exist in its benchmarking. The objective of this review is to assess how the different available data sets predict the spatiotemporal patterns of GPP, identify the differences among data sets, and highlight the main advantages/disadvantages of each data set. We compare GPP estimates for the historical period (1990-2009) from two observation-based data sets (Model Tree Ensemble and Moderate Resolution Imaging Spectroradiometer) to coupled carbon-climate models and terrestrial carbon cycle models from the Fifth Climate Model Intercomparison Project and TRENDY projects and to a new hybrid data set (CARBONES). Results show a large range in the mean global GPP estimates. The different data sets broadly agree on GPP seasonal cycle in terms of phasing, while there is still discrepancy on the amplitude. For interannual variability (IAV) and trends, there is a clear separation between the observation-based data that show little IAV and trend, while the process-based models have large GPP variability and significant trends. These results suggest that there is an urgent need to improve observation-based data sets and develop carbon cycle modeling with processes that are currently treated either very simplistically to correctly estimate present GPP and better quantify the future uptake of carbon dioxide by the world's vegetation. Key Points At global scale, direct measurements of GPP do not exist Large uncertainties exist on terrestrial global GPP benchmarking Models show large variability in mean global GPP estimates},
author = {Anav, Alessandro and Friedlingstein, Pierre and Beer, Christian and Ciais, Philippe and Harper, Anna and Jones, Chris and Murray-Tortarolo, Guillermo and Papale, Dario and Parazoo, Nicholas C. and Peylin, Philippe and Piao, Shilong and Sitch, Stephen and Viovy, Nicolas and Wiltshire, Andy and Zhao, Maosheng},
doi = {10.1002/2015RG000483},
issn = {87551209},
journal = {Reviews of Geophysics},
keywords = {DGVMs,ESMs,GPP,MTE,satellite},
month = {sep},
number = {3},
pages = {785--818},
title = {{Spatiotemporal patterns of terrestrial gross primary production: A review}},
url = {http://doi.wiley.com/10.1002/2015RG000483},
volume = {53},
year = {2015}
}
@article{Andela2017a,
abstract = {Fire is an essential Earth system process that alters ecosystem and atmospheric composition. Here we assessed long-term fire trends using multiple satellite data sets. We found that global burned area declined by 24.3 ± 8.8{\%} over the past 18 years. The estimated decrease in burned area remained robust after adjusting for precipitation variability and was largest in savannas. Agricultural expansion and intensification were primary drivers of declining fire activity. Fewer and smaller fires reduced aerosol concentrations, modified vegetation structure, and increased the magnitude of the terrestrial carbon sink. Fire models were unable to reproduce the pattern and magnitude of observed declines, suggesting that they may overestimate fire emissions in future projections. Using economic and demographic variables, we developed a conceptual model for predicting fire in human-dominated landscapes.},
author = {Andela, N. and Morton, D. C. and Giglio, L. and Chen, Y. and {Van Der Werf}, G. R. and Kasibhatla, P. S. and DeFries, R. S. and Collatz, G. J. and Hantson, S. and Kloster, S. and Bachelet, D. and Forrest, M. and Lasslop, G. and Li, F. and Mangeon, S. and Melton, J. R. and Yue, C. and Randerson, J. T.},
doi = {10.1126/science.aal4108},
issn = {10959203},
journal = {Science},
pages = {1356--1362},
pmid = {28663495},
title = {{A human-driven decline in global burned area}},
volume = {1356},
year = {2017}
}
@article{Anderegg2015,
abstract = {The terrestrial biosphere is currently a strong carbon (C) sink but may switch to a source in the 21st century as climate-driven losses exceed CO2-driven C gains, thereby accelerating global warming. Although it has long been recognized that tropical climate plays a critical role in regulating interannual climate variability, the causal link between changes in temperature and precipitation and terrestrial processes remains uncertain. Here, we combine atmospheric mass balance, remote sensing-modeled datasets of vegetation C uptake, and climate datasets to characterize the temporal variability of the terrestrial C sink and determine the dominant climate drivers of this variability. We show that the interannual variability of global land C sink has grown by 50–100{\%} over the past 50 y. We further find that interannual land C sink variability is most strongly linked to tropical nighttime warming, likely through respiration. This apparent sensitivity of respiration to nighttime temperatures, which are projected to increase faster than global average temperatures, suggests that C stored in tropical forests may be vulnerable to future warming.},
author = {Anderegg, William R. L. and Ballantyne, Ashley P. and Smith, W. Kolby and Majkut, Joseph and Rabin, Sam and Beaulieu, Claudie and Birdsey, Richard and Dunne, John P. and Houghton, Richard A. and Myneni, Ranga B. and Pan, Yude and Sarmiento, Jorge L. and Serota, Nathan and Shevliakova, Elena and Tans, Pieter and Pacala, Stephen W.},
doi = {10.1073/pnas.1521479112},
isbn = {0027-8424},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {dec},
number = {51},
pages = {201521479},
pmid = {26644555},
title = {{Tropical nighttime warming as a dominant driver of variability in the terrestrial carbon sink}},
url = {http://www.pnas.org/content/112/51/15591/tab-article-info http://www.pnas.org/lookup/doi/10.1073/pnas.1521479112},
volume = {112},
year = {2015}
}
@article{Anderegg2020,
abstract = {Forests have considerable potential to help mitigate human-caused climate change and provide society with many cobenefits. However, climate-driven risks may fundamentally compromise forest carbon sinks in the 21st century. Here, we synthesize the current understanding of climate-driven risks to forest stability from fire, drought, biotic agents, and other disturbances. We review how efforts to use forests as natural climate solutions presently consider and could more fully embrace current scientific knowledge to account for these climate-driven risks. Recent advances in vegetation physiology, disturbance ecology, mechanistic vegetation modeling, large-scale ecological observation networks, and remote sensing are improving current estimates and forecasts of the risks to forest stability. A more holistic understanding and quantification of such risks will help policy-makers and other stakeholders effectively use forests as natural climate solutions.},
author = {Anderegg, William R. L. and Trugman, Anna T. and Badgley, Grayson and Anderson, Christa M. and Bartuska, Ann and Ciais, Philippe and Cullenward, Danny and Field, Christopher B. and Freeman, Jeremy and Goetz, Scott J. and Hicke, Jeffrey A. and Huntzinger, Deborah and Jackson, Robert B. and Nickerson, John and Pacala, Stephen and Randerson, James T.},
doi = {10.1126/science.aaz7005},
issn = {0036-8075},
journal = {Science},
month = {jun},
number = {6497},
pages = {eaaz7005},
pmid = {32554569},
title = {{Climate-driven risks to the climate mitigation potential of forests}},
url = {https://www.science.org/doi/10.1126/science.aaz7005},
volume = {368},
year = {2020}
}
@article{Anderson2019,
abstract = {Abstract Enhanced ocean carbon storage during the Pleistocene ice ages lowered atmospheric CO2 concentrations by 80 to 100 ppm relative to interglacial levels. Leading hypotheses to explain this phenomenon invoke a greater efficiency of the ocean's biological pump, in which case carbon storage in the deep sea would have been accompanied by a corresponding reduction in dissolved oxygen. We exploit the sensitivity of organic matter preservation in marine sediments to bottom water oxygen concentration to constrain the level of dissolved oxygen in the deep central equatorial Pacific Ocean during the last glacial period (18,000 – 28,000 years BP) to have been within the range of 20-50 $\mu$mol/kg, much less than modern value of ca. 168 $\mu$mol/kg. We further demonstrate that reduced oxygen levels characterized the water column below a depth of {\~{}}1000 m. Converting the ice-age oxygen level to an equivalent concentration of respiratory CO2, and extrapolating globally, we estimate that deep-sea CO2 storage during the last ice age exceeded modern values by as much as 850 PgC, sufficient to balance the loss of carbon from the atmosphere (ca. 200 PgC) and from the terrestrial biosphere (ca. 300-600 PgC). In addition, recognizing the enhanced preservation of organic matter in ice-age sediments of the deep Pacific Ocean helps reconcile previously unexplained inconsistencies among different geochemical and micropaleontological proxy records used to assess past changes in biological productivity of the ocean.},
author = {Anderson, Robert F. and Sachs, Julian P. and Fleisher, Martin Q. and Allen, Katherine A. and Yu, Jimin and Koutavas, Athanasios and Jaccard, Samuel L.},
doi = {10.1029/2018GB006049},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
month = {mar},
number = {3},
pages = {301--317},
title = {{Deep‐Sea Oxygen Depletion and Ocean Carbon Sequestration During the Last Ice Age}},
url = {http://doi.wiley.com/10.1029/2018GB006049 https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GB006049},
volume = {33},
year = {2019}
}
@article{Anderson2016,
author = {Anderson, Kevin and Peters, Glen},
doi = {10.1126/science.aah4567},
issn = {0036-8075},
journal = {Science},
month = {oct},
number = {6309},
pages = {182--183},
title = {{The trouble with negative emissions}},
url = {https://www.science.org/doi/10.1126/science.aah4567},
volume = {354},
year = {2016}
}
@article{Anderson2017,
abstract = {Abstract. The Siberian shelf seas are areas of extensive biogeochemical transformation of organic matter, both of marine and terrestrial origin. This in combination with brine production from sea ice formation results in a cold bottom water of relative high salinity and partial pressure of carbon dioxide (pCO2). Data from the SWERUS-C3 expedition compiled on the icebreaker Oden in July to September 2014 show the distribution of such waters at the outer shelf, as well as their export into the deep central Arctic basins. Very high pCO2 water, up to ∼ 1000 µatm, was observed associated with high nutrients and low oxygen concentrations. Consequently, this water had low saturation state with respect to calcium carbonate down to less than 0.8 for calcite and 0.5 for aragonite. Waters undersaturated in aragonite were also observed in the surface in waters at equilibrium with atmospheric CO2; however, at these conditions the cause of under-saturation was low salinity from river runoff and/or sea ice melt. The calcium carbonate corrosive water was observed all along the continental margin and well out into the deep Makarov and Canada basins at a depth from about 50 m depth in the west to about 150 m in the east. These waters of low aragonite saturation state are traced in historic data to the Canada Basin and in the waters flowing out of the Arctic Ocean north of Greenland and in the western Fram Strait, thus potentially impacting the marine life in the North Atlantic Ocean.},
author = {Anderson, Leif G and Ek, J{\"{o}}rgen and Ericson, Ylva and Humborg, Christoph and Semiletov, Igor and Sundbom, Marcus and Ulfsbo, Adam},
doi = {10.5194/bg-14-1811-2017},
issn = {1726-4189},
journal = {Biogeosciences},
month = {apr},
number = {7},
pages = {1811--1823},
title = {{Export of calcium carbonate corrosive waters from the East Siberian Sea}},
url = {https://www.biogeosciences.net/14/1811/2017/ https://bg.copernicus.org/articles/14/1811/2017/},
volume = {14},
year = {2017}
}
@article{Andrew2019,
author = {Andrew, Robbie M.},
doi = {10.5194/essd-11-1675-2019},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {nov},
number = {4},
pages = {1675--1710},
title = {{Global CO2 emissions from cement production, 1928–2018}},
url = {https://essd.copernicus.org/articles/11/1675/2019/},
volume = {11},
year = {2019}
}
@article{Andrew2018,
abstract = {Abstract. The global production of cement has grown very rapidly in recent years, and after fossil fuels and land-use change, it is the third-largest source of anthropogenic emissions of carbon dioxide. The required data for estimating emissions from global cement production are poor, and it has been recognised that some global estimates are significantly inflated. Here we assemble a large variety of available datasets and prioritise official data and emission factors, including estimates submitted to the UNFCCC plus new estimates for China and India, to present a new analysis of global process emissions from cement production. We show that global process emissions in 2016 were 1.45±0.20 Gt CO2, equivalent to about 4 {\%} of emissions from fossil fuels. Cumulative emissions from 1928 to 2016 were 39.3±2.4 Gt CO2, 66 {\%} of which have occurred since 1990. Emissions in 2015 were 30 {\%} lower than those recently reported by the Global Carbon Project. The data associated with this article can be found at https://doi.org/10.5281/zenodo.831455.},
author = {Andrew, Robbie M},
doi = {10.5194/essd-10-195-2018},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {jan},
number = {1},
pages = {195--217},
title = {{Global CO2 emissions from cement production}},
url = {www.earth-syst-sci-data.net/10/195/2018/ https://www.earth-syst-sci-data.net/10/195/2018/ https://essd.copernicus.org/articles/10/195/2018/},
volume = {10},
year = {2018}
}
@article{Andrew2020,
abstract = {Since the first estimate of global CO2 emissions was published in 1894, important progress has been made in the development of estimation methods while the number of available datasets has grown. The existence of parallel efforts should lead to improved accuracy and understanding of emissions estimates, but there remains significant deviation between estimates and relatively poor understanding of the reasons for this. Here I describe the most important global emissions datasets available today and-by way of global, large-emitter, and case examples-quantitatively compare their estimates, exploring the reasons for differences. In many cases differences in emissions come down to differences in system boundaries: Which emissions sources are included and which are omitted. With minimal work in harmonising these system boundaries across datasets, the range of estimates of global emissions drops to 5{\%}, and further work on harmonisation would likely result in an even lower range, without changing the data. Some potential errors were found, and some discrepancies remain unexplained, but it is shown to be inappropriate to conclude that uncertainty in emissions is high simply because estimates exhibit a wide range. While "true"emissions cannot be known, by comparing different datasets methodically, differences that result from system boundaries and allocation approaches can be highlighted and set aside to enable identification of true differences, and potential errors. This must be an important way forward in improving global datasets of CO2 emissions. Data used to generate Figs. 3-18 are available at https://doi.org/10.5281/zenodo.3687042 (Andrew, 2020).},
author = {Andrew, Robbie M.},
doi = {10.5194/essd-12-1437-2020},
issn = {18663516},
journal = {Earth System Science Data},
number = {2},
pages = {1437--1465},
title = {{A comparison of estimates of global carbon dioxide emissions from fossil carbon sources}},
volume = {12},
year = {2020}
}
@article{Arevalo-Martinez2015,
author = {Ar{\'{e}}valo-Mart{\'{i}}nez, D. L. and Kock, A. and L{\"{o}}scher, C. R. and Schmitz, R. A. and Bange, H. W.},
doi = {10.1038/ngeo2469},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jul},
number = {7},
pages = {530--533},
title = {{Massive nitrous oxide emissions from the tropical South Pacific Ocean}},
url = {http://www.nature.com/articles/ngeo2469},
volume = {8},
year = {2015}
}
@article{Aragao2018,
abstract = {Tropical carbon emissions are largely derived from direct forest clearing processes. Yet, emissions from drought-induced forest fires are, usually, not included in national-level carbon emission inventories. Here we examine Brazilian Amazon drought impacts on fire incidence and associated forest fire carbon emissions over the period 2003–2015. We show that despite a 76{\%} decline in deforestation rates over the past 13 years, fire incidence increased by 36{\%} during the 2015 drought compared to the preceding 12 years. The 2015 drought had the largest ever ratio of active fire counts to deforestation, with active fires occurring over an area of 799,293 km2. Gross emissions from forest fires (989 ± 504 Tg CO2 year−1) alone are more than half as great as those from old-growth forest deforestation during drought years. We conclude that carbon emission inventories intended for accounting and developing policies need to take account of substantial forest fire emissions not associated to the deforestation process.},
author = {Arag{\~{a}}o, Luiz E O C and Anderson, Liana O and Fonseca, Marisa G and Rosan, Thais M and Vedovato, Laura B and Wagner, Fabien H and Silva, Camila V J and {Silva Junior}, Celso H L and Arai, Egidio and Aguiar, Ana P and Barlow, Jos and Berenguer, Erika and Deeter, Merritt N and Domingues, Lucas G and Gatti, Luciana and Gloor, Manuel and Malhi, Yadvinder and Marengo, Jose A and Miller, John B and Phillips, Oliver L and Saatchi, Sassan},
doi = {10.1038/s41467-017-02771-y},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {536},
title = {{21st Century drought-related fires counteract the decline of Amazon deforestation carbon emissions}},
url = {https://doi.org/10.1038/s41467-017-02771-y},
volume = {9},
year = {2018}
}
@article{Archer2009,
abstract = {We present a model of the global methane inventory as hydrate and bubbles below the sea floor. The model predicts the inventory of CH(4) in the ocean today to be approximately 1600-2,000 Pg of C. Most of the hydrate in the model is in the Pacific, in large part because lower oxygen levels enhance the preservation of organic carbon. Because the oxygen concentration today may be different from the long-term average, the sensitivity of the model to O(2) is a source of uncertainty in predicting hydrate inventories. Cold water column temperatures in the high latitudes lead to buildup of hydrates in the Arctic and Antarctic at shallower depths than is possible in low latitudes. A critical bubble volume fraction threshold has been proposed as a critical threshold at which gas migrates all through the sediment column. Our model lacks many factors that lead to heterogeneity in the real hydrate reservoir in the ocean, such as preferential hydrate formation in sandy sediments and subsurface gas migration, and is therefore conservative in its prediction of releasable methane, finding only 35 Pg of C released after 3 degrees C of uniform warming by using a 10{\%} critical bubble volume. If 2.5{\%} bubble volume is taken as critical, then 940 Pg of C might escape in response to 3 degrees C warming. This hydrate model embedded into a global climate model predicts approximately 0.4-0.5 degrees C additional warming from the hydrate response to fossil fuel CO(2) release, initially because of methane, but persisting through the 10-kyr duration of the simulations because of the CO(2) oxidation product of methane.},
annote = {added by A. Eliseev},
archivePrefix = {arXiv},
arxivId = {arXiv:1701.00462v1},
author = {Archer, D. and Buffett, B. and Brovkin, V.},
doi = {10.1073/pnas.0800885105},
eprint = {arXiv:1701.00462v1},
isbn = {0027-8424},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {dec},
number = {49},
pages = {20596--20601},
pmid = {19017807},
title = {{Ocean methane hydrates as a slow tipping point in the global carbon cycle}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.0800885105},
volume = {106},
year = {2009}
}
@article{Ardyna2020,
author = {Ardyna, Mathieu and Arrigo, Kevin Robert},
doi = {10.1038/s41558-020-0905-y},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {oct},
number = {10},
pages = {892--903},
title = {{Phytoplankton dynamics in a changing Arctic Ocean}},
url = {http://www.nature.com/articles/s41558-020-0905-y},
volume = {10},
year = {2020}
}
@article{Armour2016,
author = {Armour, Kyle C. and Marshall, John and Scott, Jeffery R. and Donohoe, Aaron and Newsom, Emily R.},
doi = {10.1038/ngeo2731},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jul},
number = {7},
pages = {549--554},
title = {{Southern Ocean warming delayed by circumpolar upwelling and equatorward transport}},
url = {http://www.nature.com/articles/ngeo2731},
volume = {9},
year = {2016}
}
@article{ArmstrongMcKay2018,
author = {{Armstrong McKay}, D I and Lenton, T M},
doi = {10.5194/cp-14-1515-2018},
journal = {Climate of the Past},
number = {10},
pages = {1515--1527},
title = {{Reduced carbon cycle resilience across the Palaeocene–Eocene Thermal Maximum}},
volume = {14},
year = {2018}
}
@article{Arneth2010,
abstract = {The terrestrial biosphere is a key regulator of atmospheric chemistry and climate. During past periods of climate change, vegetation cover and interactions between the terrestrial biosphere and atmosphere changed within decades. Modern observations show a similar responsiveness of terrestrial biogeochemistry to anthropogenically forced climate change and air pollution. Although interactions between the carbon cycle and climate have been a central focus, other biogeochemical feedbacks could be as important in modulating future climate change. Total positive radiative forcings resulting from feedbacks between the terrestrial biosphere and the atmosphere are estimated to reach up to 0.9 or 1.5 W m−2 K−1 towards the end of the twenty-first century, depending on the extent to which interactions with the nitrogen cycle stimulate or limit carbon sequestration. This substantially reduces and potentially even eliminates the cooling effect owing to carbon dioxide fertilization of the terrestrial biota. The overall magnitude of the biogeochemical feedbacks could potentially be similar to that of feedbacks in the physical climate system, but there are large uncertainties in the magnitude of individual estimates and in accounting for synergies between these effects.},
author = {Arneth, A. and Harrison, S. P. and Zaehle, S. and Tsigaridis, K. and Menon, S. and Bartlein, P. J. and Feichter, J. and Korhola, A. and Kulmala, M. and O'Donnell, D. and Schurgers, G. and Sorvari, S. and Vesala, T.},
doi = {10.1038/ngeo905},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {aug},
number = {8},
pages = {525--532},
publisher = {Nature Publishing Group},
title = {{Terrestrial biogeochemical feedbacks in the climate system}},
url = {http://dx.doi.org/10.1038/ngeo905 http://www.nature.com/articles/ngeo905},
volume = {3},
year = {2010}
}
@article{Arneth2017,
abstract = {The terrestrial biosphere absorbs about 20{\%} of fossil-fuel CO2 emissions. The overall magnitude of this sink is constrained by the difference between emissions, the rate of increase in atmospheric CO2 concentrations, and the ocean sink. However, the land sink is actually composed of two largely counteracting fluxes that are poorly quantified: fluxes from land-use change and CO2 uptake by terrestrial ecosystems. Dynamic global vegetation model simulations suggest that CO2 emissions from land-use change have been substantially underestimated because processes such as tree harvesting and land clearing from shifting cultivation have not been considered. As the overall terrestrial sink is constrained, a larger net flux as a result of land-use change implies that terrestrial uptake of CO2 is also larger, and that terrestrial ecosystems might have greater potential to sequester carbon in the future. Consequently, reforestation projects and efforts to avoid further deforestation could represent important mitigation pathways, with co-benefits for biodiversity. It is unclear whether a larger land carbon sink can be reconciled with our current understanding of terrestrial carbon cycling. Our possible underestimation of the historical residual terrestrial carbon sink adds further uncertainty to our capacity to predict the future of terrestrial carbon uptake and losses.},
author = {Arneth, A. and Sitch, S. and Pongratz, J. and Stocker, B. D. and Ciais, P. and Poulter, B. and Bayer, A. D. and Bondeau, A. and Calle, L. and Chini, L. P. and Gasser, T. and Fader, M. and Friedlingstein, P. and Kato, E. and Li, W. and Lindeskog, M. and Nabel, J. E. M. S. and Pugh, T. A. M. and Robertson, E. and Viovy, N. and Yue, C. and Zaehle, S.},
doi = {10.1038/ngeo2882},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {feb},
number = {2},
pages = {79--84},
title = {{Historical carbon dioxide emissions caused by land-use changes are possibly larger than assumed}},
url = {https://www.nature.com/articles/ngeo2882 http://www.nature.com/articles/ngeo2882},
volume = {10},
year = {2017}
}
@article{Arora2013,
abstract = {AbstractThe magnitude and evolution of parameters that characterize feedbacks in the coupled carbon–climate system are compared across nine Earth system models (ESMs). The analysis is based on results from biogeochemically, radiatively, and fully coupled simulations in which CO2 increases at a rate of 1{\%} yr−1. These simulations are part of phase 5 of the Coupled Model Intercomparison Project (CMIP5). The CO2 fluxes between the atmosphere and underlying land and ocean respond to changes in atmospheric CO2 concentration and to changes in temperature and other climate variables. The carbon–concentration and carbon–climate feedback parameters characterize the response of the CO2 flux between the atmosphere and the underlying surface to these changes. Feedback parameters are calculated using two different approaches. The two approaches are equivalent and either may be used to calculate the contribution of the feedback terms to diagnosed cumulative emissions. The contribution of carbon–concentration feedback to...},
author = {Arora, Vivek K. and Boer, George J. and Friedlingstein, Pierre and Eby, Michael and Jones, Chris D. and Christian, James R. and Bonan, Gordon and Bopp, Laurent and Brovkin, Victor and Cadule, Patricia and Hajima, Tomohiro and Ilyina, Tatiana and Lindsay, Keith and Tjiputra, Jerry F. and Wu, Tongwen},
doi = {10.1175/JCLI-D-12-00494.1},
isbn = {0894-8755$\backslash$r1520-0442},
issn = {0894-8755},
journal = {Journal of Climate},
month = {aug},
number = {15},
pages = {5289--5314},
pmid = {1331},
title = {{Carbon–concentration and carbon–climate feedbacks in CMIP5 Earth system models}},
url = {http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00494.1},
volume = {26},
year = {2013}
}
@article{Arora2018c,
abstract = {The terrestrial biosphere currently absorbs about 30{\%} of anthropogenic CO2 emissions. This carbon uptake over land results primarily from vegetation's response to increasing atmospheric CO2 but other factors also play a role. Here we show that since the 1930s increasing population densities and cropland area have decreased global area burned, consistent with the charcoal record and recent satellite-based observations. The associated reduced wildfire emissions from increase in cropland area do not enhance carbon uptake since natural vegetation that is spared burning was deforested anyway. However, reduction in fire CO2 emissions due to fire suppression and landscape fragmentation associated with increases in population density is calculated to enhance land carbon uptake by 0.13 Pg C yr-1, or {\~{}}19{\%} of the global land carbon uptake (0.7 ± 0.6 Pg C yr-1), for the 1960-2009 period. These results identify reduction in global wildfire CO2 emissions as yet another mechanism that is currently enhancing carbon uptake over land.},
author = {Arora, Vivek K. and Melton, Joe R.},
doi = {10.1038/s41467-018-03838-0},
issn = {20411723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {1326},
publisher = {Springer US},
title = {{Reduction in global area burned and wildfire emissions since 1930s enhances carbon uptake by land}},
url = {http://www.nature.com/articles/s41467-018-03838-0 http://dx.doi.org/10.1038/s41467-018-03838-0},
volume = {9},
year = {2018}
}
@article{Arora2020c,
author = {Arora, Vivek K. and Katavouta, Anna and Williams, Richard G. and Jones, Chris D. and Brovkin, Victor and Friedlingstein, Pierre and Schwinger, J{\"{o}}rg and Bopp, Laurent and Boucher, Olivier and Cadule, Patricia and Chamberlain, Matthew A. and Christian, James R. and Delire, Christine and Fisher, Rosie A. and Hajima, Tomohiro and Ilyina, Tatiana and Joetzjer, Emilie and Kawamiya, Michio and Koven, Charles D. and Krasting, John P. and Law, Rachel M. and Lawrence, David M. and Lenton, Andrew and Lindsay, Keith and Pongratz, Julia and Raddatz, Thomas and S{\'{e}}f{\'{e}}rian, Roland and Tachiiri, Kaoru and Tjiputra, Jerry F. and Wiltshire, Andy and Wu, Tongwen and Ziehn, Tilo},
doi = {10.5194/bg-17-4173-2020},
issn = {1726-4189},
journal = {Biogeosciences},
month = {aug},
number = {16},
pages = {4173--4222},
title = {{Carbon–concentration and carbon–climate feedbacks in CMIP6 models and their comparison to CMIP5 models}},
url = {https://bg.copernicus.org/articles/17/4173/2020/},
volume = {17},
year = {2020}
}
@article{https://doi.org/10.1002/ppp.2074,
abstract = {Abstract In recent years, new geophysical phenomena have been observed in the high-latitude regions of continental permafrost. Since 2014 new craters 10–20 m in diameter have been found within the Yamal Peninsula and neighboring regions. They are associated with the emissions of gases, which could have been formed during dissociation of relict gas hydrate deposits due to increases in soil temperature. This paper presents the results of numerical modeling of the thermal regime of permafrost in the north of Western Siberia with the assessment of methane hydrate stability zone under climate changes over the past 130,000 years. According to the results obtained, the upper boundary of the methane hydrate stability zone in Yamal could have reached the surface within the periods of glacial maxima (about 90,000 and 60,000 years ago). We show that at present in Yamal permafrost above the modern boundary of the stability zone, relic methane hydrates are likely to exist at depths of up to 100–150 m, they could have “survives” warming during the Holocene optimum about 6,000 years ago and remain in permafrost rocks under negative temperatures even under transgression and increased geothermal flux conditions.},
author = {Arzhanov, Maxim M and Malakhova, Valentina V and Mokhov, Igor I},
doi = {10.1002/ppp.2074},
journal = {Permafrost and Periglacial Processes},
keywords = {climate change,gas-emission craters,ice sheet,methane hydrates,modeling,permafrost},
number = {4},
pages = {487--496},
title = {{Modeling thermal regime and evolution of the methane hydrate stability zone of the Yamal peninsula permafrost}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/ppp.2074},
volume = {31},
year = {2020}
}
@article{Arzhanov2016,
abstract = {This paper considers the impact of current climatic change on the permafrost strength and stability of relic gas hydrates in the Yamal Peninsula based on the results of permafrost thermal regime simulations and model estimates of climate change within last 100 ka.},
annote = {added by A.Eliseev 25.01.2019},
author = {Arzhanov, M M and Mokhov, I I and Denisov, S N},
doi = {10.1134/S1028334X1606009X},
issn = {1028-334X},
journal = {Doklady Earth Sciences},
month = {jun},
number = {2},
pages = {616--618},
title = {{Impact of regional climatic change on the stability of relic gas hydrates}},
url = {https://doi.org/10.1134/S1028334X1606009X http://link.springer.com/10.1134/S1028334X1606009X},
volume = {468},
year = {2016}
}
@article{Arzhanov2017,
abstract = {Modelling of the thermal regime of permafrost soils has made it possible to estimate the stability of methane hydrates in the continental permafrost in the Northern Eurasian and North American regions with the risk of gas emissions into the atmosphere as a result of possible dissociation of gas hydrates in the Holocene Optimum and under contemporary climatic conditions [1, 2].},
annote = {added by A.Eliseev 25.01.2019},
author = {Arzhanov, M M and Mokhov, I I},
doi = {10.1134/S1028334X17100026},
issn = {1028-334X},
journal = {Doklady Earth Sciences},
month = {oct},
number = {2},
pages = {1163--1167},
title = {{Stability of continental relic methane hydrates for the holocene climatic optimum and for contemporary conditions}},
url = {https://doi.org/10.1134/S1028334X17100026 http://link.springer.com/10.1134/S1028334X17100026},
volume = {476},
year = {2017}
}
@article{Astor2013a,
abstract = {We examined the variability of sea surface carbon dioxide fugacity (fCO2sea) and its relation to temperature at the Cariaco Basin ocean time-series location (10°30'N, 64°40'W) for the period from 1996 through 2008. Periods of warm (positive) and cold (negative) anomalies at the station were related to variability in coastal upwelling intensity. A positive temporal trend in monthly-deseasonalized sea surface temperatures (SST) was observed, leading to an overall increase of 1.13{\&}{\#}xa0;°C over 13 years. Surface fCO2sea displayed significant short-term variation (month to month) with a range of 330 to 445{\&}{\#}xa0;µatm. In addition to a large seasonal range (58±17{\&}{\#}xa0;µatm), deseasonalized fCO2sea data showed an interannual positive trend of 1.77±0.43{\&}{\#}xa0;µatm{\&}{\#}xa0;year−1. In the Cariaco Basin, positive and negative anomalies of temperature and fCO2sea are in phase. An increase/decrease of 1{\&}{\#}xa0;°C coincides with an increase/decrease of 16–20{\&}{\#}xa0;µatm of fCO2sea. Deseasonalized fCO2sea normalized to 26.05{\&}{\#}xa0;°C, the mean Cariaco SST, shows a lower rate of increase (0.51±0.49{\&}{\#}xa0;µatm{\&}{\#}xa0;year−1). Based on these observations, 72{\%} of the increase in fCO2sea in Cariaco Basin between 1996 and 2008 can be attributed to an increasing temperature trend of surface waters, making this the primary factor controlling fugacity at this location. During this period, a decrease in upwelling intensity was also observed. The phytoplankton community changed from large diatom-dominated blooms during upwelling in the late 1990's to blooms dominated by smaller cells in the first decade of the twenty-first century. The average net sea-air CO2 flux over the study period is 2.0±2.6{\&}{\#}xa0;mol{\&}{\#}xa0;C{\&}{\#}xa0;m−2{\&}{\#}xa0;year−1 employing the Wanninkhof parameterization, and 2.1±2.5{\&}{\#}xa0;mol{\&}{\#}xa0;C{\&}{\#}xa0;m−2{\&}{\#}xa0;year−1 based on Nightingale's model. To further understand the connection between the changes observed in the Cariaco Basin, the relationships between interannual variability in the temperature anomaly with three modes of climate variability (AMO, NAO and ENSO) were examined.},
author = {Astor, Y.M. and Lorenzoni, L and Thunell, R and Varela, R and Muller-Karger, F and Troccoli, L and Taylor, G.T. and Scranton, M.I. and Tappa, E and Rueda, D},
doi = {10.1016/j.dsr2.2013.01.002},
issn = {09670645},
journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
month = {sep},
pages = {33--43},
title = {{Interannual variability in sea surface temperature and fCO2 changes in the Cariaco Basin}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0967064513000039},
volume = {93},
year = {2013}
}
@article{Atwood2017,
abstract = {Mangrove soils represent a large sink for otherwise rapidly recycled carbon (C). However, widespread deforestation threatens the preservation of this important C stock. It is therefore imperative that global patterns in mangrove soil C stocks and their susceptibility to remineralization are understood. Here, we present patterns in mangrove soil C stocks across hemispheres, latitudes, countries and mangrove community compositions, and estimate potential annual CO2 emissions for countries where mangroves occur. Global potential CO2 emissions from soils as a result of mangrove loss were estimated to be {\~{}}7.0 Tg CO2e yr−1. Countries with the highest potential CO2 emissions from soils are Indonesia (3,410 Gg CO2e yr−1) and Malaysia (1,288 Gg CO2e yr−1). The patterns described serve as a baseline by which countries can assess their mangrove soil C stocks and potential emissions from mangrove deforestation.},
author = {Atwood, Trisha B. and Connolly, Rod M. and Almahasheer, Hanan and Carnell, Paul E. and Duarte, Carlos M. and {Ewers Lewis}, Carolyn J. and Irigoien, Xabier and Kelleway, Jeffrey J. and Lavery, Paul S. and Macreadie, Peter I. and Serrano, Oscar and Sanders, Christian J. and Santos, Isaac and Steven, Andrew D. L. and Lovelock, Catherine E.},
doi = {10.1038/nclimate3326},
isbn = {1758-678X},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jul},
number = {7},
pages = {523--528},
title = {{Global patterns in mangrove soil carbon stocks and losses}},
url = {http://www.nature.com/articles/nclimate3326},
volume = {7},
year = {2017}
}
@article{Auger2021,
abstract = {Despite playing a major role in global ocean heat storage, the Southern Ocean remains the most sparsely measured region of the global ocean. Here, a unique 25-year temperature time-series of the upper 800 m, repeated several times a year across the Southern Ocean, allows us to document the long-term change within water-masses and how it compares to the interannual variability. Three regions stand out as having strong trends that dominate over interannual variability: warming of the subantarctic waters (0.29 ± 0.09 °C per decade); cooling of the near-surface subpolar waters (−0.07 ± 0.04 °C per decade); and warming of the subsurface subpolar deep waters (0.04 ± 0.01 °C per decade). Although this subsurface warming of subpolar deep waters is small, it is the most robust long-term trend of our section, being in a region with weak interannual variability. This robust warming is associated with a large shoaling of the maximum temperature core in the subpolar deep water (39 ± 09 m per decade), which has been significantly underestimated by a factor of 3 to 10 in past studies. We find temperature changes of comparable magnitude to those reported in Amundsen–Bellingshausen Seas, which calls for a reconsideration of current ocean changes with important consequences for our understanding of future Antarctic ice-sheet mass loss.},
author = {Auger, Matthis and Morrow, Rosemary and Kestenare, Elodie and Sall{\'{e}}e, Jean-Baptiste and Cowley, Rebecca},
doi = {10.1038/s41467-020-20781-1},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {514},
title = {{Southern Ocean in-situ temperature trends over 25 years emerge from interannual variability}},
url = {http://www.nature.com/articles/s41467-020-20781-1},
volume = {12},
year = {2021}
}
@article{doi:10.1029/2009JC005917,
abstract = {Ocean acidification is predicted to occur first in polar oceans. We investigated the saturation state of waters with respect to calcite ($\Omega$cal) and aragonite ($\Omega$arg) in six sections along an Arctic outflow pathway through the Canadian Arctic Archipelago (CAA) and into the northwestern Atlantic using dissolved inorganic carbon and total alkalinity measurements from 2003 to 2005. The study area, a key region connecting the Arctic and the North Atlantic, includes Smith Sound, Barrow Strait, Baffin Bay, Davis Strait, Hudson Strait, and the Labrador Sea. The average $\Omega$arg in the Arctic outflow was 1.18 ± 0.17 in Barrow Strait and 1.31 ± 0.14 in Smith Sound, with areas where $\Omega$arg {\textless} 1. The Arctic outflow through the CAA has a high content of Pacific waters, which have a low saturation state. These waters can be traced along the western Baffin Bay to Davis Strait. South of Davis Strait, this outflow is modified by mixing with slope and offshore waters of Atlantic origin and with the outflow from Hudson Strait. Despite the mixing, low saturation state water can still be identified on the southern Labrador Shelf. The aragonite saturation horizon is found at ∼150 m in Barrow Strait; at 200 m in Baffin Bay, Davis Strait, and Hudson Strait; and at 2300 m in the Labrador Sea. This study provides baseline data of the saturation states for the waters of the CAA and the northwest Atlantic. It also illustrates the downstream evolution of low saturation state Arctic outflow in the northwest Atlantic.},
author = {Azetsu-Scott, Kumiko and Clarke, Allyn and Falkner, Kelly and Hamilton, James and Jones, E Peter and Lee, Craig and Petrie, Brian and Prinsenberg, Simon and Starr, Michel and Yeats, Philip},
doi = {10.1029/2009JC005917},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Arctic outflow,Canadian Arctic Archipelago,Labrador Sea,ocean acidification,pH,saturation state},
month = {nov},
number = {C11},
pages = {C11021},
title = {{Calcium carbonate saturation states in the waters of the Canadian Arctic Archipelago and the Labrador Sea}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2009JC005917 http://doi.wiley.com/10.1029/2009JC005917},
volume = {115},
year = {2010}
}
@article{Banda2016,
abstract = {Abstract. The CH4 growth rate in the atmosphere showed large variations after the Pinatubo eruption in June 1991. A decrease of more than 10ppbyr{\&}minus;1 in the growth rate over the course of 1992 was reported, and a partial recovery in the following year. Although several reasons have been proposed to explain the evolution of CH4 after the eruption, their contributions to the observed variations are not yet resolved. CH4 is removed from the atmosphere by the reaction with tropospheric OH, which in turn is produced by O3 photolysis under UV radiation. The CH4 removal after the Pinatubo eruption might have been affected by changes in tropospheric UV levels due to the presence of stratospheric SO2 and sulfate aerosols, and due to enhanced ozone depletion on Pinatubo aerosols. The perturbed climate after the eruption also altered both sources and sinks of atmospheric CH4. Furthermore, CH4 concentrations were influenced by other factors of natural variability in that period, such as El Ni{\~{n}}o–Southern Oscillation (ENSO) and biomass burning events. Emissions of CO, NOX and non-methane volatile organic compounds (NMVOCs) also affected CH4 concentrations indirectly by influencing tropospheric OH levels. Potential drivers of CH4 variability are investigated using the TM5 global chemistry model. The contribution that each driver had to the global CH4 variability during the period 1990 to 1995 is quantified. We find that a decrease of 8{\&}ndash;10ppbyr{\&}minus;1 CH4 is explained by a combination of the above processes. However, the timing of the minimum growth rate is found 6{\&}nash;9 months later than observed. The long-term decrease in CH4 growth rate over the period 1990 to 1995 is well captured and can be attributed to an increase in OH concentrations over this time period. Potential uncertainties in our modelled CH4 growth rate include emissions of CH4 from wetlands, biomass burning emissions of CH4 and other compounds, biogenic NMVOC and the sensitivity of OH to NMVOC emission changes. Two inventories are used for CH4 emissions from wetlands, ORCHIDEE and LPJ, to investigate the role of uncertainties in these emissions. Although the higher climate sensitivity of ORCHIDEE improves the simulated CH4 growth rate change after Pinatubo, none of the two inventories properly captures the observed CH4 variability in this period.},
author = {B{\^{a}}ndă, N and Krol, M and van Weele, M. and van Noije, T. and {Le Sager}, P. and R{\"{o}}ckmann, T},
doi = {10.5194/acp-16-195-2016},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {jan},
number = {1},
pages = {195--214},
title = {{Can we explain the observed methane variability after the Mount Pinatubo eruption?}},
url = {https://www.atmos-chem-phys.net/16/195/2016/},
volume = {16},
year = {2016}
}
@article{Babbin2015b,
abstract = {Because N2O is a potent greenhouse gas, tracking its sources and sinks - including those from natural processes - is imperative. Babbin et al. developed an isotopic tracer method to measure biological N2O reduction rates directly in the Eastern Tropical North Pacific Ocean. Incomplete denitrification results in the rapid cycling and net accumulation of N2O. As oxygen minimum zones expand in the global ocean, more N2O may enter the atmosphere than previously expected.Science, this issue p. 1127Nitrous oxide (N2O) is a powerful greenhouse gas and a major cause of stratospheric ozone depletion, yet its sources and sinks remain poorly quantified in the oceans. We used isotope tracers to directly measure N2O reduction rates in the eastern tropical North Pacific. Because of incomplete denitrification, N2O cycling rates are an order of magnitude higher than predicted by current models in suboxic regions, and the spatial distribution suggests strong dependence on both organic carbon and dissolved oxygen concentrations. Furthermore, N2O turnover is 20 times higher than the net atmospheric efflux. The rapid rate of this cycling coupled to an expected expansion of suboxic ocean waters implies future increases in N2O emissions.},
author = {Babbin, Andrew R and Bianchi, Daniele and Jayakumar, Amal and Ward, Bess B},
doi = {10.1126/science.aaa8380},
journal = {Science},
month = {jun},
number = {6239},
pages = {1127--1129},
publisher = {American Association for the Advancement of Science},
title = {{Rapid nitrous oxide cycling in the suboxic ocean}},
url = {http://science.sciencemag.org/content/348/6239/1127 http://www.sciencemag.org/cgi/doi/10.1126/science.aaa8380},
volume = {348},
year = {2015}
}
@article{Babila2018,
author = {Babila, Tali L. and Penman, Donald E. and H{\"{o}}nisch, B{\"{a}}rbel and Kelly, D. Clay and Bralower, Timothy J. and Rosenthal, Yair and Zachos, James C.},
doi = {10.1098/rsta.2017.0072},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {oct},
number = {2130},
pages = {20170072},
title = {{Capturing the global signature of surface ocean acidification during the Palaeocene–Eocene Thermal Maximum}},
url = {http://rsta.royalsocietypublishing.org/lookup/doi/10.1098/rsta.2017.0072},
volume = {376},
year = {2018}
}
@article{Bacastow1980,
abstract = {The observed rate of change of the atmospheric carbon dioxide concentration at the South Pole, Fanning Island, Hawaii, and ocean weather station P correlates with an index of the southern oscillation and with El Ni{\~{n}}o occurrences. There are changes at all four stations that seem to be in response to the weak 1975 El Ni{\~{n}}o. Thus, even poorly developed El Ni{\~{n}}o events may affect the atmospheric carbon dioxide concentration.},
author = {Bacastow, R. B. and Adams, J. A. and Keeling, C. D. and Moss, D. J. and Whorf, T. P. and Wong, C. S.},
doi = {10.1126/science.210.4465.66},
issn = {0036-8075},
journal = {Science},
month = {oct},
number = {4465},
pages = {66--68},
publisher = {A},
title = {{Atmospheric carbon dioxide, the Southern oscillation, and the weak 1975 El Nino}},
url = {http://science.sciencemag.org/content/210/4465/66 http://www.sciencemag.org/cgi/doi/10.1126/science.210.4465.66},
volume = {210},
year = {1980}
}
@article{Bach2016,
author = {Bach, L. T. and Boxhammer, T. and Larsen, A. and Hildebrandt, N. and Schulz, K. G. and Riebesell, U.},
doi = {10.1002/2016GB005372},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {aug},
number = {8},
pages = {1145--1165},
title = {{Influence of plankton community structure on the sinking velocity of marine aggregates}},
url = {http://doi.wiley.com/10.1002/2016GB005372},
volume = {30},
year = {2016}
}
@article{Bach2019,
author = {Bach, Lennart T. and Gill, Sophie J. and Rickaby, Rosalind E. M. and Gore, Sarah and Renforth, Phil},
doi = {10.3389/fclim.2019.00007},
issn = {2624-9553},
journal = {Frontiers in Climate},
month = {oct},
pages = {7},
title = {{CO2 Removal With Enhanced Weathering and Ocean Alkalinity Enhancement: Potential Risks and Co-benefits for Marine Pelagic Ecosystems}},
url = {https://www.frontiersin.org/article/10.3389/fclim.2019.00007/full},
volume = {1},
year = {2019}
}
@article{Bachman2020,
abstract = {Ocean ventilation is the process by which climatically important tracers such as heat and carbon are exchanged between the atmosphere and ocean interior. In this paper a series of numerical simulations are used to study the interaction of submesoscales and a topographically steered jet in driving rapid ventilation. The ventilation is found to increase both as a function of wind stress and model resolution, with a submesoscale-resolving 1/120° model exhibiting the largest ventilation rate. The jet in this simulation is found to be persistently unstable to submesoscale instabilities, which are known to feature intense vertical circulations. The vertical tracer transport is found to scale as a function of the eddy kinetic energy and mean isopycnal slope, whose behaviors change as a function of the wind stress and due to the emergence of a strong potential vorticity gradient due to the lateral shear of the jet. These results highlight the importance of jet-submesoscale interaction as a bridge between the atmosphere and the ocean interior.},
author = {Bachman, Scott D. and Klocker, Andreas},
doi = {10.1175/JPO-D-20-0117.1},
issn = {15200485},
journal = {Journal of Physical Oceanography},
keywords = {Baroclinic flows,Barotropic flows,Instability,Turbulence,Vertical motion},
month = {sep},
number = {10},
pages = {2873--2883},
publisher = {American Meteorological Society},
title = {{Interaction of jets and submesoscale dynamics leads to rapid ocean ventilation}},
url = {https://journals.ametsoc.org/view/journals/phoc/50/10/jpoD200117.xml},
volume = {50},
year = {2020}
}
@article{Badgley2017,
abstract = {Global estimates of terrestrial gross primary production (GPP) remain highly uncertain, despite decades of satellite measurements and intensive in situ monitoring. We report a new approach for quantifying the near-infrared reflectance of terrestrial vegetation (NIRV). NIRV provides a foundation for a new approach to estimate GPP that consistently untangles the confounding effects of background brightness, leaf area, and the distribution of photosynthetic capacity with depth in canopies using existing moderate spatial and spectral resolution satellite sensors. NIRV is strongly correlated with solar-induced chlorophyll fluorescence, a direct index of photons intercepted by chlorophyll, and with site-level and globally gridded estimates of GPP. NIRV makes it possible to use existing and future reflectance data as a starting point for accurately estimating GPP.},
author = {Badgley, Grayson and Field, Christopher B. and Berry, Joseph A.},
doi = {10.1126/sciadv.1602244},
issn = {23752548},
journal = {Science Advances},
number = {3},
pages = {e1602244},
title = {{Canopy near-infrared reflectance and terrestrial photosynthesis}},
volume = {3},
year = {2017}
}
@article{Baggenstos14881,
abstract = {Earth{\{}$\backslash$textquoteright{\}}s radiative imbalance determines whether energy is flowing into or out of the ocean{\{}$\backslash$textendash{\}}atmosphere system. The present, anthropogenic, positive imbalance drives global warming. This study reconstructs the radiative imbalance for the last deglaciation, {\~{}}20,000 to 10,000 y ago. During the deglaciation, a positive imbalance was maintained for several thousand years, which brought the climate system from the last ice age into the Holocene warm period. We show that the imbalance varied significantly during this time, possibly due to changes in ocean circulation that affect the radiative energy fluxes, highlighting the importance of internal variability in Earth{\{}$\backslash$textquoteright{\}}s energy budget.The energy imbalance at the top of the atmosphere determines the temporal evolution of the global climate, and vice versa changes in the climate system can alter the planetary energy fluxes. This interplay is fundamental to our understanding of Earth{\{}$\backslash$textquoteright{\}}s heat budget and the climate system. However, even today, the direct measurement of global radiative fluxes is difficult, such that most assessments are based on changes in the total energy content of the climate system. We apply the same approach to estimate the long-term evolution of Earth{\{}$\backslash$textquoteright{\}}s radiative imbalance in the past. New measurements of noble gas-derived mean ocean temperature from the European Project for Ice Coring in Antarctica Dome C ice core covering the last 40,000 y, combined with recent results from the West Antarctic Ice Sheet Divide ice core and the sea-level record, allow us to quantitatively reconstruct the history of the climate system energy budget. The temporal derivative of this quantity must be equal to the planetary radiative imbalance. During the deglaciation, a positive imbalance of typically +0.2 W.m-2 is maintained for {\~{}}10,000 y, however, with two distinct peaks that reach up to 0.4 W.m-2 during times of substantially reduced Atlantic Meridional Overturning Circulation. We conclude that these peaks are related to net changes in ocean heat uptake, likely due to rapid changes in North Atlantic deep-water formation and their impact on the global radiative balance, while changes in cloud coverage, albeit uncertain, may also factor into the picture.},
author = {Baggenstos, Daniel and H{\"{a}}berli, Marcel and Schmitt, Jochen and Shackleton, Sarah A and Birner, Benjamin and Severinghaus, Jeffrey P and Kellerhals, Thomas and Fischer, Hubertus},
doi = {10.1073/pnas.1905447116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {30},
pages = {14881--14886},
publisher = {National Academy of Sciences},
title = {{Earth's radiative imbalance from the Last Glacial Maximum to the present}},
url = {https://www.pnas.org/content/116/30/14881},
volume = {116},
year = {2019}
}
@article{Baig2015,
abstract = {The temperature dependence of the reaction kinetics of the Rubisco enzyme implies that, at the level of a chloroplast, the response of photosynthesis to rising atmospheric CO2 concentration (Ca) will increase with increasing air temperature. Vegetation models incorporating this interaction predict that the response of net primary productivity (NPP) to elevated CO2 (eCa) will increase with rising temperature and will be substantially larger in warm tropical forests than in cold boreal forests. We tested these model predictions against evidence from eCa experiments by carrying out two meta-analyses. Firstly, we tested for an interaction effect on growth responses in factorial eCa × temperature experiments. This analysis showed a positive, but nonsignificant interaction effect (95{\%} CI for above-ground biomass response = −0.8, 18.0{\%}) between eCa and temperature. Secondly, we tested field-based eCa experiments on woody plants across the globe for a relationship between the eCa effect on plant biomass and mean annual temperature (MAT). This second analysis showed a positive but nonsignificant correlation between the eCa response and MAT. The magnitude of the interactions between CO2 and temperature found in both meta-analyses were consistent with model predictions, even though both analyses gave nonsignificant results. Thus, we conclude that it is not possible to distinguish between the competing hypotheses of no interaction vs. an interaction based on Rubisco kinetics from the available experimental database. Experiments in a wider range of temperature zones are required. Until such experimental data are available, model predictions should aim to incorporate uncertainty about this interaction.},
author = {Baig, Sofia and Medlyn, Belinda E. and Mercado, Lina M. and Zaehle, S{\"{o}}nke},
doi = {10.1111/gcb.12962},
isbn = {1096-987X},
issn = {13652486},
journal = {Global Change Biology},
keywords = {Effect size,Log response ratio,Meta-analysis,Meta-regression,Photosynthesis,Rubisco},
number = {12},
pages = {4303--4319},
pmid = {25940760},
title = {{Does the growth response of woody plants to elevated CO2 increase with temperature? A model-oriented meta-analysis}},
volume = {21},
year = {2015}
}
@article{Bakker2016,
abstract = {Abstract. The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled fCO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million fCO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million fCO2 values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water fCO2 values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water fCO2 has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. High-profile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) "living data" publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014). Individual data set files, included in the synthesis product, can be downloaded here: doi:10.1594/PANGAEA.849770. The gridded products are available here: doi:10.3334/CDIAC/OTG.SOCAT{\_}V3{\_}GRID.},
author = {Bakker, Dorothee C. E. and Pfeil, Benjamin and Landa, Camilla S. and Metzl, Nicolas and O{\&}apos;Brien, Kevin M. and Olsen, Are and Smith, Karl and Cosca, Cathy and Harasawa, Sumiko and Jones, Stephen D. and Nakaoka, Shin-ichiro and Nojiri, Yukihiro and Schuster, Ute and Steinhoff, Tobias and Sweeney, Colm and Takahashi, Taro and Tilbrook, Bronte and Wada, Chisato and Wanninkhof, Rik and Alin, Simone R. and Balestrini, Carlos F. and Barbero, Leticia and Bates, Nicholas R. and Bianchi, Alejandro A. and Bonou, Fr{\'{e}}d{\'{e}}ric and Boutin, Jacqueline and Bozec, Yann and Burger, Eugene F. and Cai, Wei-Jun and Castle, Robert D. and Chen, Liqi and Chierici, Melissa and Currie, Kim and Evans, Wiley and Featherstone, Charles and Feely, Richard A. and Fransson, Agneta and Goyet, Catherine and Greenwood, Naomi and Gregor, Luke and Hankin, Steven and Hardman-Mountford, Nick J. and Harlay, J{\'{e}}r{\^{o}}me and Hauck, Judith and Hoppema, Mario and Humphreys, Matthew P. and Hunt, Christopher W. and Huss, Betty and Ib{\'{a}}nhez, J. Severino P. and Johannessen, Truls and Keeling, Ralph and Kitidis, Vassilis and K{\"{o}}rtzinger, Arne and Kozyr, Alex and Krasakopoulou, Evangelia and Kuwata, Akira and Landsch{\"{u}}tzer, Peter and Lauvset, Siv K. and Lef{\`{e}}vre, Nathalie and {Lo Monaco}, Claire and Manke, Ansley and Mathis, Jeremy T. and Merlivat, Liliane and Millero, Frank J. and Monteiro, Pedro M. S. and Munro, David R. and Murata, Akihiko and Newberger, Timothy and Omar, Abdirahman M. and Ono, Tsuneo and Paterson, Kristina and Pearce, David and Pierrot, Denis and Robbins, Lisa L. and Saito, Shu and Salisbury, Joe and Schlitzer, Reiner and Schneider, Bernd and Schweitzer, Roland and Sieger, Rainer and Skjelvan, Ingunn and Sullivan, Kevin F. and Sutherland, Stewart C. and Sutton, Adrienne J. and Tadokoro, Kazuaki and Telszewski, Maciej and Tuma, Matthias and van Heuven, Steven M. A. C. and Vandemark, Doug and Ward, Brian and Watson, Andrew J. and Xu, Suqing},
doi = {10.5194/essd-8-383-2016},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {sep},
number = {2},
pages = {383--413},
title = {{A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)}},
url = {https://www.earth-syst-sci-data.net/8/383/2016/},
volume = {8},
year = {2016}
}
@article{Bakun2015a,
abstract = {Ecosystem productivity in coastal ocean upwelling systems is threatened by climate change. Increases in spring and summer upwelling intensity, and associated increases in the rate of offshore advection, are expected. While this could counter effects of habitat warming, it could also lead to more frequent hypoxic events and lower densities of suitable-sized food particles for fish larvae. With upwelling intensification, ocean acidity will rise, affecting organisms with carbonate structures. Regardless of changes in upwelling, near-surface stratification, turbulent diffusion rates, source water origins, and perhaps thermocline depths associated with large-scale climate episodes (ENSO) maybe affected. Major impacts on pelagic fish resources appear unlikely unless couples with overfishing, although changes toward more subtropical community composition are likely. Marine mammals and seabirds that are tied to sparsely distributed nesting or resting grounds could experience difficulties in obtaining prey resources, or adaptively respond by moving to more favorable biogeographic provinces.},
author = {Bakun, A and Black, B A and Bograd, S J and Garc{\'{i}}a-Reyes, M and Miller, A J and Rykaczewski, R R and Sydeman, W J},
doi = {10.1007/s40641-015-0008-4},
issn = {2198-6061},
journal = {Current Climate Change Reports},
month = {jun},
number = {2},
pages = {85--93},
title = {{Anticipated Effects of Climate Change on Coastal Upwelling Ecosystems}},
volume = {1},
year = {2015}
}
@article{Balesdent2018,
abstract = {The exchange of carbon between soil organic carbon (SOC) and the atmosphere affects the climate1,2 and—because of the importance of organic matter to soil fertility—agricultural productivity3. The dynamics of topsoil carbon has been relatively well quantified4, but half of the soil carbon is located in deeper soil layers (below 30 centimetres)5–7, and many questions remain regarding the exchange of this deep carbon with the atmosphere8. This knowledge gap restricts soil carbon management policies and limits global carbon models1,9,10. Here we quantify the recent incorporation of atmosphere-derived carbon atoms into whole-soil profiles, through a meta-analysis of changes in stable carbon isotope signatures at 112 grassland, forest and cropland sites, across different climatic zones, from 1965 to 2015. We find, in agreement with previous work5,6, that soil at a depth of 30–100 centimetres beneath the surface (the subsoil) contains on average 47 per cent of the topmost metre's SOC stocks. However, we show that this subsoil accounts for just 19 per cent of the SOC that has been recently incorporated (within the past 50 years) into the topmost metre. Globally, the median depth of recent carbon incorporation into mineral soil is 10 centimetres. Variations in the relative allocation of carbon to deep soil layers are better explained by the aridity index than by mean annual temperature. Land use for crops reduces the incorporation of carbon into the soil surface layer, but not into deeper layers. Our results suggest that SOC dynamics and its responses to climatic control or land use are strongly dependent on soil depth. We propose that using multilayer soil modules in global carbon models, tested with our data, could help to improve our understanding of soil–atmosphere carbon exchange.},
author = {Balesdent, J{\'{e}}r{\^{o}}me and Basile-Doelsch, Isabelle and Chadoeuf, Jo{\"{e}}l and Cornu, Sophie and Derrien, Delphine and Fekiacova, Zuzana and Hatt{\'{e}}, Christine},
doi = {10.1038/s41586-018-0328-3},
issn = {1476-4687},
journal = {Nature},
number = {7715},
pages = {599--602},
title = {{Atmosphere–soil carbon transfer as a function of soil depth}},
url = {https://doi.org/10.1038/s41586-018-0328-3},
volume = {559},
year = {2018}
}
@article{Ballantyne2017,
abstract = {The recent ‘warming hiatus' presents an excellent opportunity to investigate climate sensitivity of carbon cycle processes. Here we combine satellite and atmospheric observations to show that the rate of net biome productivity (NBP) has significantly accelerated from −0.007 ± 0.065 PgC yr−2 over the warming period (1982 to 1998) to 0.119 ± 0.071 PgC yr−2 over the warming hiatus (1998–2012). This acceleration in NBP is not due to increased primary productivity, but rather reduced respiration that is correlated (r = 0.58; P = 0.0007) and sensitive ($\gamma$ = 4.05 to 9.40 PgC yr−1 per °C) to land temperatures. Global land models do not fully capture this apparent reduced respiration over the warming hiatus; however, an empirical model including soil temperature and moisture observations better captures the reduced respiration.},
author = {Ballantyne, Ashley and Smith, William and Anderegg, William and Kauppi, Pekka and Sarmiento, Jorge and Tans, Pieter and Shevliakova, Elena and Pan, Yude and Poulter, Benjamin and Anav, Alessandro and Friedlingstein, Pierre and Houghton, Richard and Running, Steven},
doi = {10.1038/nclimate3204},
isbn = {1758-678X},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {feb},
number = {2},
pages = {148--152},
publisher = {Nature Publishing Group},
title = {{Accelerating net terrestrial carbon uptake during the warming hiatus due to reduced respiration}},
url = {http://dx.doi.org/10.1038/nclimate3204 http://10.0.4.14/nclimate3204 https://www.nature.com/articles/nclimate3204{\#}supplementary-information http://www.nature.com/articles/nclimate3204},
volume = {7},
year = {2017}
}
@article{Ballantyne2012,
abstract = {One of the greatest sources of uncertainty for future climate predictions is the response of the global carbon cycle to climate change. Although approximately one-half of total CO(2) emissions is at present taken up by combined land and ocean carbon reservoirs, models predict a decline in future carbon uptake by these reservoirs, resulting in a positive carbon-climate feedback. Several recent studies suggest that rates of carbon uptake by the land and ocean have remained constant or declined in recent decades. Other work, however, has called into question the reported decline. Here we use global-scale atmospheric CO(2) measurements, CO(2) emission inventories and their full range of uncertainties to calculate changes in global CO(2) sources and sinks during the past 50 years. Our mass balance analysis shows that net global carbon uptake has increased significantly by about 0.05 billion tonnes of carbon per year and that global carbon uptake doubled, from 2.4 ± 0.8 to 5.0 ± 0.9 billion tonnes per year, between 1960 and 2010. Therefore, it is very unlikely that both land and ocean carbon sinks have decreased on a global scale. Since 1959, approximately 350 billion tonnes of carbon have been emitted by humans to the atmosphere, of which about 55 per cent has moved into the land and oceans. Thus, identifying the mechanisms and locations responsible for increasing global carbon uptake remains a critical challenge in constraining the modern global carbon budget and predicting future carbon-climate interactions.},
author = {Ballantyne, A. P. and Alden, C. B. and Miller, J. B. and Tans, P. P. and White, J. W. C.},
doi = {10.1038/nature11299},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7409},
pages = {70--72},
pmid = {22859203},
title = {{Increase in observed net carbon dioxide uptake by land and oceans during the past 50 years}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/22859203 http://www.nature.com/articles/nature11299},
volume = {488},
year = {2012}
}
@article{Barker2002,
author = {Barker, Stephen and Elderfield, Henry},
doi = {10.1126/science.1072815},
issn = {00368075},
journal = {Science},
month = {aug},
number = {5582},
pages = {833--836},
title = {{Foraminiferal Calcification Response to Glacial-Interglacial Changes in Atmospheric CO2}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1072815 https://www.sciencemag.org/lookup/doi/10.1126/science.1072815},
volume = {297},
year = {2002}
}
@article{Bastviken50,
abstract = {Inland waters (lakes, reservoirs, streams, and rivers) are often substantial methane (CH4) sources in the terrestrial landscape. They are, however, not yet well integrated in global greenhouse gas (GHG) budgets. Data from 474 freshwater ecosystems and the most recent global water area estimates indicate that freshwaters emit at least 103 teragrams of CH4 year-1, corresponding to 0.65 petagrams of C as carbon dioxide (CO2) equivalents year-1, offsetting 25{\%} of the estimated land carbon sink. Thus, the continental GHG sink may be considerably overestimated, and freshwaters need to be recognized as important in the global carbon cycle.},
author = {Bastviken, David and Tranvik, Lars J and Downing, John A and Crill, Patrick M and Enrich-Prast, Alex},
doi = {10.1126/science.1196808},
issn = {0036-8075},
journal = {Science},
month = {jan},
number = {6013},
pages = {50--50},
publisher = {American Association for the Advancement of Science},
title = {{Freshwater Methane Emissions Offset the Continental Carbon Sink}},
url = {http://science.sciencemag.org/content/331/6013/50 http://www.sciencemag.org/cgi/doi/10.1126/science.1196808},
volume = {331},
year = {2011}
}
@article{Bates2009a,
abstract = {Calcium carbonate (CaCO3) mineral saturation states for aragonite ($\Omega$aragonite) and calcite ($\Omega$calcite) are calculated for waters of the Chukchi Sea shelf and Canada Basin of the western Arctic Ocean during the Shelf-Basin Interactions project from 2002 to 2004. On the Chukchi Sea shelf, a strong seasonality and vertical differentiation of aragonite and calcite saturation states was observed. During the summertime sea ice retreat period, high rates of phytoplankton primary production and net community production act to increase the $\Omega$aragonite and $\Omega$calcite of surface waters, while subsurface waters become undersaturated with respect to aragonite due primarily to remineralization of organic matter to CO2. This seasonal ?phytoplankton-carbonate saturation state? interaction induces strong undersaturation of aragonite ($\Omega$aragonite = {\textless}0.7?1) at ?40?150 m depth in the northern Chukchi Sea and in the Canada Basin within upper halocline waters at ?100?200 m depth. Patches of aragonite undersaturated surface water were also found in the Canada Basin resulting from significant sea ice melt contributions ({\textgreater}10{\%}). The seasonal aragonite undersaturation of waters observed on the Chukchi Sea shelf is likely a recent phenomenon that results from the uptake of anthropogenic CO2 and subsequent ocean acidification, with seasonality of saturation states superimposed by biological processes. These undersaturated waters are potentially highly corrosive to calcifying benthic fauna (e.g., bivalves and echinoderms) found on the shelf, with implications for the food sources of large benthic feeding mammals (e.g., walrus, gray whales, and bearded seals). The benthic ecosystem of the Chukchi Sea (and other Arctic Ocean shelves) is thus potentially vulnerable to future ocean acidification and suppression of CaCO3 saturation states.},
annote = {doi: 10.1029/2008JC004862},
author = {Bates, Nicholas R and Mathis, Jeremy T and Cooper, Lee W},
doi = {10.1029/2008JC004862},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Oceans},
keywords = {carbon dioxide},
month = {nov},
number = {C11},
pages = {C11007},
publisher = {Wiley-Blackwell},
title = {{Ocean acidification and biologically induced seasonality of carbonate mineral saturation states in the western Arctic Ocean}},
url = {https://doi.org/10.1029/2008JC004862 http://doi.wiley.com/10.1029/2008JC004862},
volume = {114},
year = {2009}
}
@article{Bates2014b,
annote = {From Duplicate 1 (A Time-Series View of Changing Ocean Chemistry Due to Ocean Uptake of Anthropogenic CO2 and Ocean Acidification - Bates, Nicholas; Astor, Yrene; Church, Matthew; Currie, Kim; Dore, John; Gona{\'{a}}lez-D{\'{a}}vila, Melchor; Lorenzoni, Laura; Muller-Karger, Frank; Olafsson, Jon; Santa-Casiano, Magdalena)

From Duplicate 1 (A time-series view of changing ocean chemistry due to ocean uptake of anthropogenic CO2 and ocean acidification - Bates, Nicholas R; Astor, Yrene M Astor; Church, Matthew J; Currie, Kim; Dore, John E; Gona{\'{a}}lez-D{\'{a}}vila, Melchor; Lorenzoni, Laura; Muller-Karger, Frank; Olafsson, Jon; Santa-Casiano, Magdalena; Gonz{\'{a}}lez-D{\'{a}}vila,, Melchor; Laura, Lorenzoni; Muller-Karger, Frank; Olafsson, Jon; Santana-Casiano, J Magdalena)

From Duplicate 1 (A Time-Series View of Changing Ocean Chemistry Due to Ocean Uptake of Anthropogenic CO2 and Ocean Acidification - Bates, Nicholas R; Astor, Yrene M Astor; Church, Matthew J; Currie, Kim; Dore, John E; Gonz{\'{a}}lez-D{\'{a}}vila,, Melchor; Laura, Lorenzoni; Muller-Karger, Frank; Olafsson, Jon; Santana-Casiano, J Magdalena)

Sustained observations provide critically needed data and understanding not only about ocean warming and water cycle reorganization (e.g., salinity changes), ocean eutrophication, and ocean deoxygenation, but also about changes in ocean chemistry. As an example of changes in the global ocean carbon cycle, consistent changes in surface seawater CO2-carbonate chemistry are documented by seven independent CO2 time series that provide sustained ocean observations collected for periods from 15 to 30 years: (1) Iceland Sea, (2) Irminger Sea, (3) Bermuda Atlantic Time-series Study (BATS), (4) European Station for Time series in the Ocean at the Canary Islands (ESTOC), (5) CArbon Retention In A Colored Ocean sites in the North Atlantic (CARIACO), (6) Hawaii Ocean Time-series (HOT), and (7) Munida in the Pacific Ocean. These ocean time-series sites exhibit very consistent changes in surface ocean chemistry that reflect the impact of uptake of anthropogenic CO2 and ocean acidification. The article discusses the long-term changes in dissolved inorganic carbon (DIC), salinity-normalized DIC, and surface seawater pCO2 (partial pressure of CO2) due to the uptake of anthropogenic CO2 and its impact on the ocean�fs buffering capacity. In addition, we evaluate changes in seawater chemistry that are due to ocean acidification and its impact on pH and saturation states for biogenic calcium carbonate minerals.

From Duplicate 2 (A Time-Series View of Changing Ocean Chemistry Due to Ocean Uptake of Anthropogenic CO2 and Ocean Acidification - Bates, Nicholas; Astor, Yrene; Church, Matthew; Currie, Kim; Dore, John; Gona{\'{a}}lez-D{\'{a}}vila, Melchor; Lorenzoni, Laura; Muller-Karger, Frank; Olafsson, Jon; Santa-Casiano, Magdalena)

From Duplicate 1 (A Time-Series View of Changing Ocean Chemistry Due to Ocean Uptake of Anthropogenic CO2 and Ocean Acidification - Bates, Nicholas R; Astor, Yrene M Astor; Church, Matthew J; Currie, Kim; Dore, John E; Gonz{\'{a}}lez-D{\'{a}}vila,, Melchor; Laura, Lorenzoni; Muller-Karger, Frank; Olafsson, Jon; Santana-Casiano, J Magdalena)

Sustained observations provide critically needed data and understanding not only about ocean warming and water cycle reorganization (e.g., salinity changes), ocean eutrophication, and ocean deoxygenation, but also about changes in ocean chemistry. As an example of changes in the global ocean carbon cycle, consistent changes in surface seawater CO2-carbonate chemistry are documented by seven independent CO2 time series that provide sustained ocean observations collected for periods from 15 to 30 years: (1) Iceland Sea, (2) Irminger Sea, (3) Bermuda Atlantic Time-series Study (BATS), (4) European Station for Time series in the Ocean at the Canary Islands (ESTOC), (5) CArbon Retention In A Colored Ocean sites in the North Atlantic (CARIACO), (6) Hawaii Ocean Time-series (HOT), and (7) Munida in the Pacific Ocean. These ocean time-series sites exhibit very consistent changes in surface ocean chemistry that reflect the impact of uptake of anthropogenic CO2 and ocean acidification. The article discusses the long-term changes in dissolved inorganic carbon (DIC), salinity-normalized DIC, and surface seawater pCO2 (partial pressure of CO2) due to the uptake of anthropogenic CO2 and its impact on the ocean�fs buffering capacity. In addition, we evaluate changes in seawater chemistry that are due to ocean acidification and its impact on pH and saturation states for biogenic calcium carbonate minerals.

From Duplicate 2 (A Time-Series View of Changing Ocean Chemistry Due to Ocean Uptake of Anthropogenic CO2 and Ocean Acidification - Bates, Nicholas; Astor, Yrene; Church, Matthew; Currie, Kim; Dore, John; Gona{\'{a}}lez-D{\'{a}}vila, Melchor; Lorenzoni, Laura; Muller-Karger, Frank; Olafsson, Jon; Santa-Casiano, Magdalena)

From Duplicate 1 (A Time-Series View of Changing Ocean Chemistry Due to Ocean Uptake of Anthropogenic CO2 and Ocean Acidification - Bates, Nicholas R; Astor, Yrene M Astor; Church, Matthew J; Currie, Kim; Dore, John E; Gonz{\'{a}}lez-D{\'{a}}vila,, Melchor; Laura, Lorenzoni; Muller-Karger, Frank; Olafsson, Jon; Santana-Casiano, J Magdalena)

Sustained observations provide critically needed data and understanding not only about ocean warming and water cycle reorganization (e.g., salinity changes), ocean eutrophication, and ocean deoxygenation, but also about changes in ocean chemistry. As an example of changes in the global ocean carbon cycle, consistent changes in surface seawater CO2-carbonate chemistry are documented by seven independent CO2 time series that provide sustained ocean observations collected for periods from 15 to 30 years: (1) Iceland Sea, (2) Irminger Sea, (3) Bermuda Atlantic Time-series Study (BATS), (4) European Station for Time series in the Ocean at the Canary Islands (ESTOC), (5) CArbon Retention In A Colored Ocean sites in the North Atlantic (CARIACO), (6) Hawaii Ocean Time-series (HOT), and (7) Munida in the Pacific Ocean. These ocean time-series sites exhibit very consistent changes in surface ocean chemistry that reflect the impact of uptake of anthropogenic CO2 and ocean acidification. The article discusses the long-term changes in dissolved inorganic carbon (DIC), salinity-normalized DIC, and surface seawater pCO2 (partial pressure of CO2) due to the uptake of anthropogenic CO2 and its impact on the ocean�fs buffering capacity. In addition, we evaluate changes in seawater chemistry that are due to ocean acidification and its impact on pH and saturation states for biogenic calcium carbonate minerals.

From Duplicate 3 (A Time-Series View of Changing Ocean Chemistry Due to Ocean Uptake of Anthropogenic CO2 and Ocean Acidification - Bates, Nicholas R; Astor, Yrene M Astor; Church, Matthew J; Currie, Kim; Dore, John E; Gonz{\'{a}}lez-D{\'{a}}vila,, Melchor; Laura, Lorenzoni; Muller-Karger, Frank; Olafsson, Jon; Santana-Casiano, J Magdalena)

Sustained observations provide critically needed data and understanding not only about ocean warming and water cycle reorganization (e.g., salinity changes), ocean eutrophication, and ocean deoxygenation, but also about changes in ocean chemistry. As an example of changes in the global ocean carbon cycle, consistent changes in surface seawater CO2-carbonate chemistry are documented by seven independent CO2 time series that provide sustained ocean observations collected for periods from 15 to 30 years: (1) Iceland Sea, (2) Irminger Sea, (3) Bermuda Atlantic Time-series Study (BATS), (4) European Station for Time series in the Ocean at the Canary Islands (ESTOC), (5) CArbon Retention In A Colored Ocean sites in the North Atlantic (CARIACO), (6) Hawaii Ocean Time-series (HOT), and (7) Munida in the Pacific Ocean. These ocean time-series sites exhibit very consistent changes in surface ocean chemistry that reflect the impact of uptake of anthropogenic CO2 and ocean acidification. The article discusses the long-term changes in dissolved inorganic carbon (DIC), salinity-normalized DIC, and surface seawater pCO2 (partial pressure of CO2) due to the uptake of anthropogenic CO2 and its impact on the ocean�fs buffering capacity. In addition, we evaluate changes in seawater chemistry that are due to ocean acidification and its impact on pH and saturation states for biogenic calcium carbonate minerals.},
author = {Bates, Nicholas R. and Astor, Yrene and Church, Matthew and Currie, Kim and Dore, John and Gona{\'{a}}lez-D{\'{a}}vila, Melchor and Lorenzoni, Laura and Muller-Karger, Frank and Olafsson, Jon and Santa-Casiano, Magdalena},
doi = {10.5670/oceanog.2014.16},
issn = {10428275},
journal = {Oceanography},
month = {mar},
number = {1},
pages = {126--141},
title = {{A Time-Series View of Changing Ocean Chemistry Due to Ocean Uptake of Anthropogenic CO2 and Ocean Acidification}},
url = {https://doi.org/10.5670/oceanog.2014.16 https://tos.org/oceanography/article/a-time-series-view-of-changing-ocean-chemistry-due-to-ocean-uptake-ofanthro},
volume = {27},
year = {2014}
}
@article{Bates2020,
abstract = {Ocean chemical and physical conditions are changing. Here we show decadal variability and recent acceleration of surface warming, salinification, deoxygenation, carbon dioxide (CO 2 ) and acidification in the subtropical North Atlantic Ocean (Bermuda Atlantic Time-series Study site; 1980s to present). Surface temperatures and salinity exhibited interdecadal variability, increased by {\~{}}0.85 °C (with recent warming of 1.2 °C) and 0.12, respectively, while dissolved oxygen levels decreased by {\~{}}8{\%} ({\~{}}2{\%} per decade). Concurrently, seawater DIC, f CO 2 (fugacity of CO 2 ) and anthropogenic CO 2 increased by {\~{}}8{\%}, 22{\%}, and 72{\%} respectively. The winter versus summer f CO 2 difference increased by 4 to 8 µatm decade −1 due to seasonally divergent thermal and alkalinity changes. Ocean pH declined by 0.07 ({\~{}}17{\%} increase in acidity) and other acidification indicators by {\~{}}10{\%}. Over the past nearly forty years, the highest increase in ocean CO 2 and ocean acidification occurred during decades of weakest atmospheric CO 2 growth and vice versa.},
author = {Bates, Nicholas Robert and Johnson, Rodney J},
doi = {10.1038/s43247-020-00030-5},
issn = {2662-4435},
journal = {Communications Earth {\&} Environment},
month = {dec},
number = {1},
pages = {33},
title = {{Acceleration of ocean warming, salinification, deoxygenation and acidification in the surface subtropical North Atlantic Ocean}},
url = {https://doi.org/10.1038/s43247-020-00030-5 http://www.nature.com/articles/s43247-020-00030-5},
volume = {1},
year = {2020}
}
@article{Bathiany2010,
author = {Bathiany, S. and Claussen, M. and Brovkin, V. and Raddatz, T. and Gayler, V.},
doi = {10.5194/bg-7-1383-2010},
issn = {1726-4189},
journal = {Biogeosciences},
month = {may},
number = {5},
pages = {1383--1399},
title = {{Combined biogeophysical and biogeochemical effects of large-scale forest cover changes in the MPI earth system model}},
url = {http://www.biogeosciences.net/7/1383/2010/},
volume = {7},
year = {2010}
}
@article{10.1175/JCLI-D-19-0449.1,
abstract = {The most discernible and devastating impacts of climate change are caused by events with temporary extreme conditions (“extreme events”) or abrupt shifts to a new persistent climate state (“tipping points”). The rapidly growing amount of data from models and observations poses the challenge to reliably detect where, when, why, and how these events occur. This situation calls for data-mining approaches that can detect and diagnose events in an automatic and reproducible way. Here, we apply a new strategy to this task by generalizing the classical machine-vision problem of detecting edges in 2D images to many dimensions (including time). Our edge detector identifies abrupt or extreme climate events in spatiotemporal data, quantifies their abruptness (or extremeness), and provides diagnostics that help one to understand the causes of these shifts. We also publish a comprehensive toolset of code that is documented and free to use. We document the performance of the new edge detector by analyzing several datasets of observations and models. In particular, we apply it to all monthly 2D variables of the RCP8.5 scenario of the Coupled Model Intercomparison Project (CMIP5). More than half of all simulations show abrupt shifts of more than 4 standard deviations on a time scale of 10 years. These shifts are mostly related to the loss of sea ice and permafrost in the Arctic. Our results demonstrate that the edge detector is particularly useful to scan large datasets in an efficient way, for example multimodel or perturbed-physics ensembles. It can thus help to reveal hidden “climate surprises” and to assess the uncertainties of dangerous climate events.},
author = {Bathiany, Sebastian and Hidding, Johan and Scheffer, Marten},
doi = {10.1175/JCLI-D-19-0449.1},
issn = {0894-8755},
journal = {Journal of Climate},
number = {15},
pages = {6399--6421},
title = {{Edge Detection Reveals Abrupt and Extreme Climate Events}},
url = {https://doi.org/10.1175/JCLI-D-19-0449.1},
volume = {33},
year = {2020}
}
@article{Batjes2016,
abstract = {Soils play a key role in providing a range of ecosystem services. Quality-assessed soil information, with quantified uncertainty levels, is needed to address a range of global issues. Traditional mapping methods, which recognize that soil classes are "important carriers of soil information", were used to prepare an updated harmonized dataset of derived soil properties for the world at a nominal resolution of 30 by 30 arc sec (WISE30sec). The map unit composition was determined using an overlay of the Harmonized World Soil Database, with minor corrections, and the K{\"{o}}ppen-Geiger climate zones map as categorical co-variate. Property estimates for the respective component soil units were derived using taxonomy-based transfer rules that draw on a statistical analysis of some 21,000 soil profiles. Best estimates (mean ± standard deviation) for twenty soil properties were calculated for seven depth intervals (up to 2 m depth or less when thinner): organic carbon content, total nitrogen, C/N ratio, pH(H2O), CECsoil, CECclay, effective CEC, total exchangeable bases (TEB), base saturation, aluminium saturation, calcium carbonate content, gypsum content, exchangeable sodium percentage (ESP), electrical conductivity, particle size distribution (content of sand, silt and clay), proportion of coarse fragments ({\textgreater}2 mm), bulk density, and available water capacity (-33 to -1500 kPa); also the dominant soil drainage class. Coefficients of variation tend to be large. WISE30sec may be used for applications at a broad scale ({\textless}1:1 M) upon consideration of the underlying data lineage, generalizations, and the associated uncertainties. As an example, the database was used to calculate the global soil organic carbon (SOC) stock to 2 m depth. Some 30{\%} (607 ± 87 Pg C) of this stock (2060 ± 215 Pg C) is held in the Northern Circumpolar Region, which is considered most sensitive to climate change.},
author = {Batjes, N.H.},
doi = {10.1016/j.geoderma.2016.01.034},
issn = {00167061},
journal = {Geoderma},
keywords = {Data harmonization,Derived soil properties,Environmental modelling,Soil carbon stocks,Taxotransfer rules,Uncertainty estimates},
month = {may},
pages = {61--68},
publisher = {Elsevier B.V.},
title = {{Harmonized soil property values for broad-scale modelling (WISE30sec) with estimates of global soil carbon stocks}},
url = {http://dx.doi.org/10.1016/j.geoderma.2016.01.034 https://linkinghub.elsevier.com/retrieve/pii/S0016706116300349},
volume = {269},
year = {2016}
}
@article{Battaglia2018a,
author = {Battaglia, Gianna and Joos, Fortunat},
doi = {10.5194/esd-9-797-2018},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {jun},
number = {2},
pages = {797--816},
publisher = {Copernicus Publications},
title = {{Hazards of decreasing marine oxygen: the near-term and millennial-scale benefits of meeting the Paris climate targets}},
url = {https://www.earth-syst-dynam.net/9/797/2018/ https://www.earth-syst-dynam.net/9/797/2018/esd-9-797-2018.pdf},
volume = {9},
year = {2018}
}
@article{Battaglia2018b,
abstract = {Nitrous oxide (N2O) is a potent greenhouse gas (GHG) and ozone destructing agent; yet global estimates of N2O emissions are uncertain. Marine N2O stems from nitrification and denitrification processes which depend on organic matter cycling and dissolved oxygen (O2). We introduce N2O as an obligate intermediate product of denitrification and as an O2‐dependent by‐product from nitrification in the Bern3D ocean model. A large model ensemble is used to probabilistically constrain modern and to project marine N2O production for a low (Representative Concentration Pathway (RCP)2.6) and high GHG (RCP8.5) scenario extended to A.D. 10,000. Water column N2O and surface ocean partial pressure N2O data serve as constraints in this Bayesian framework. The constrained median for modern N2O production is 4.5 (±1$\sigma$ range: 3.0 to 6.1) Tg N yr−1, where 4.5{\%} stems from denitrification. Modeled denitrification is 65.1 (40.9 to 91.6) Tg N yr−1, well within current estimates. For high GHG forcing, N2O production decreases by 7.7{\%} over this century due to decreasing organic matter export and remineralization. Thereafter, production increases slowly by 21{\%} due to widespread deoxygenation and high remineralization. Deoxygenation peaks in two millennia, and the global O2 inventory is reduced by a factor of 2 compared to today. Net denitrification is responsible for 7.8{\%} of the long‐term increase in N2O production. On millennial timescales, marine N2O emissions constitute a small, positive feedback to climate change. Our simulations reveal tight coupling between the marine carbon cycle, O2, N2O, and climate.},
author = {Battaglia, G. and Joos, F.},
doi = {10.1002/2017GB005671},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {jan},
number = {1},
pages = {92--121},
publisher = {Wiley-Blackwell},
title = {{Marine N2O Emissions From Nitrification and Denitrification Constrained by Modern Observations and Projected in Multimillennial Global Warming Simulations}},
url = {http://doi.wiley.com/10.1002/2017GB005671},
volume = {32},
year = {2018}
}
@article{Baumgartner2014,
abstract = {During the last glacial cycle, Greenland temperature showed many rapid temperature variations, the so-called Dansgaard-Oeschger (DO) events. The past atmospheric methane concentration closely followed these temperature variations, which implies that the warmings recorded in Greenland were probably hemispheric in extent. Here we substantially extend and complete the North Greenland Ice Core Project (NGRIP) methane record from the Preboreal Holocene (PB) back to the end of the last interglacial period with a mean time resolution of 54 yr. We relate the amplitudes of the methane increases associated with DO events to the amplitudes of the local Greenland NGRIP temperature increases derived from stable nitrogen isotope ($\delta$15N) measurements, which have been performed along the same ice core (Kindler et al., 2014). We find the ratio to oscillate between 5 parts per billion (ppb) per °C and 18 ppb °Cg -1 with the approximate frequency of the precessional cycle. A remarkably high ratio of 25.5 ppb °Cg-1 is reached during the transition from the Younger Dryas (YD) to the PB. Analysis of the timing of the fast methane and temperature increases reveals significant lags of the methane increases relative to NGRIP temperature for DO events 5, 9, 10, 11, 13, 15, 19, and 20. These events generally have small methane increase rates and we hypothesize that the lag is caused by pronounced northward displacement of the source regions from stadial to interstadial. We further show that the relative interpolar concentration difference (rIPD) of methane is about 4.5{\%} for the stadials between DO events 18 and 20, which is in the same order as in the stadials before and after DO event 2 around the Last Glacial Maximum. The rIPD of methane remains relatively stable throughout the full last glacial, with a tendency for elevated values during interstadial compared to stadial periods. {\textcopyright} 2014 Author(s) CC Attribution 3.0 License.},
author = {Baumgartner, M. and Kindler, P. and Eicher, O. and Floch, G. and Schilt, A. and Schwander, J. and Spahni, R. and Capron, E. and Chappellaz, J. and Leuenberger, M. and Fischer, H. and Stocker, T. F.},
doi = {10.5194/cp-10-903-2014},
issn = {18149332},
journal = {Climate of the Past},
number = {2},
pages = {903--920},
title = {{NGRIP CH4 concentration from 120 to 10 kyr before present and its relation to a $\delta$15N temperature reconstruction from the same ice core}},
volume = {10},
year = {2014}
}
@article{doi:10.1029/2018GL077881,
abstract = {Abstract Changes in atmospheric CO2 on millennial-to-centennial timescales are key components of past climate variability during the last glacial and deglacial periods (70–10 ka), yet the sources and mechanisms responsible for the CO2 fluctuations remain largely obscure. Here we report the 13C/12C ratio of atmospheric CO2 during a key interval of the last glacial period at submillennial resolution, with coeval histories of atmospheric CO2, CH4, and N2O concentrations. The carbon isotope data suggest that the millennial-scale CO2 variability in Marine Isotope Stage 3 is driven largely by changes in the organic carbon cycle, most likely by sequestration of respired carbon in the deep ocean. Centennial-scale CO2 variations, distinguished by carbon isotope signatures, are associated with both abrupt hydrological change in the tropics (e.g., Heinrich events) and rapid increases in Northern Hemisphere temperature (Dansgaard-Oeschger events). These events can be linked to modes of variability during the last deglaciation, thus suggesting that drivers of millennial and centennial CO2 variability during both periods are intimately linked to abrupt climate variability.},
author = {Bauska, T K and Brook, E J and Marcott, S A and Baggenstos, D and Shackleton, S and Severinghaus, J P and Petrenko, V V},
doi = {10.1029/2018GL077881},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {atmospheric CO2,carbon cycle,ice cores,paleoclimate},
month = {aug},
number = {15},
pages = {7731--7740},
title = {{Controls on Millennial-Scale Atmospheric CO2 Variability During the Last Glacial Period}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL077881 http://doi.wiley.com/10.1029/2018GL077881},
volume = {45},
year = {2018}
}
@article{Beaufort2011,
abstract = {About one-third of the carbon dioxide (CO(2)) released into the atmosphere as a result of human activity has been absorbed by the oceans, where it partitions into the constituent ions of carbonic acid. This leads to ocean acidification, one of the major threats to marine ecosystems and particularly to calcifying organisms such as corals, foraminifera and coccolithophores. Coccolithophores are abundant phytoplankton that are responsible for a large part of modern oceanic carbonate production. Culture experiments investigating the physiological response of coccolithophore calcification to increased CO(2) have yielded contradictory results between and even within species. Here we quantified the calcite mass of dominant coccolithophores in the present ocean and over the past forty thousand years, and found a marked pattern of decreasing calcification with increasing partial pressure of CO(2) and concomitant decreasing concentrations of CO(3)(2-). Our analyses revealed that differentially calcified species and morphotypes are distributed in the ocean according to carbonate chemistry. A substantial impact on the marine carbon cycle might be expected upon extrapolation of this correlation to predicted ocean acidification in the future. However, our discovery of a heavily calcified Emiliania huxleyi morphotype in modern waters with low pH highlights the complexity of assemblage-level responses to environmental forcing factors.},
archivePrefix = {arXiv},
arxivId = {NIHMS150003},
author = {Beaufort, L. and Probert, I. and de Garidel-Thoron, T. and Bendif, E. M. and Ruiz-Pino, D. and Metzl, N. and Goyet, C. and Buchet, N. and Coupel, P. and Grelaud, M. and Rost, B. and Rickaby, R. E. M. and de Vargas, C.},
doi = {10.1038/nature10295},
eprint = {NIHMS150003},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7358},
pages = {80--83},
pmid = {21814280},
title = {{Sensitivity of coccolithophores to carbonate chemistry and ocean acidification}},
url = {http://www.nature.com/articles/nature10295},
volume = {476},
year = {2011}
}
@article{Beaulieu2019,
author = {Beaulieu, Jake J. and DelSontro, Tonya and Downing, John A.},
doi = {10.1038/s41467-019-09100-5},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {1375},
title = {{Eutrophication will increase methane emissions from lakes and impoundments during the 21st century}},
url = {http://www.nature.com/articles/s41467-019-09100-5},
volume = {10},
year = {2019}
}
@article{Beaupre-Laperriere2020,
abstract = {Abstract. Ocean acidification driven by the uptake of anthropogenic CO2 by the surface oceans constitutes a potential threat to the health of marine ecosystems around the globe. The Arctic Ocean is particularly vulnerable to acidification and thus is an ideal region to study the progression and effects of acidification before they become globally widespread. The appearance of undersaturated surface waters with respect to the carbonate mineral aragonite ($\Omega$A},
author = {Beaupr{\'{e}}-Laperri{\`{e}}re, Alexis and Mucci, Alfonso and Thomas, Helmuth},
doi = {10.5194/bg-17-3923-2020},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jul},
number = {14},
pages = {3923--3942},
title = {{The recent state and variability of the carbonate system of the Canadian Arctic Archipelago and adjacent basins in the context of ocean acidification}},
url = {https://bg.copernicus.org/articles/17/3923/2020/},
volume = {17},
year = {2020}
}
@article{Beck2018,
abstract = {Atmospheric methane concentration shows a wellknown decrease over the first half of the Holocene following the Northern Hemisphere summer insolation before it started to increase again to preindustrial values. There is a debate about what caused this change in the methane concentration evolution, in particular, whether an early anthropogenic influence or natural emissions led to the reversal of the atmospheric CH4 concentration evolution. Here, we present new methane concentration and stable hydrogen and carbon isotope data measured on ice core samples from both Greenland and Antarctica over the Holocene. With the help of a two-box model and the full suite of CH4 parameters, the new data allow us to quantify the total methane emissions in the Northern Hemisphere and Southern Hemisphere separately as well as their stable isotopic signatures, while interpretation of isotopic records of only one hemisphere may lead to erroneous conclusions. For the first half of the Holocene our results indicate an asynchronous decrease in Northern Hemisphere and Southern Hemisphere CH4 emissions by more than 30 TgCH4 yr-1 in total, accompanied by a drop in the northern carbon isotopic source signature of about-3‰. This cannot be explained by a change in the source mix alone but requires shifts in the isotopic signature of the sources themselves caused by changes in the precursor material for the methane production. In the second half of the Holocene, global CH4 emissions increased by about 30 TgCH4 yr-1, while preindustrial isotopic emission signatures remained more or less constant. However, our results show that this early increase in methane emissions took place in the Southern Hemisphere, while Northern Hemisphere emissions started to increase only about 2000 years ago. Accordingly, natural emissions in the southern tropics appear to be the main cause of the CH4 increase starting 5000 years before present, not supporting an early anthropogenic influence on the global methane budget by East Asian land use changes.},
author = {Beck, Jonas and Bock, Michael and Schmitt, Jochen and Seth, Barbara and Blunier, Thomas and Fischer, Hubertus},
doi = {10.5194/bg-15-7155-2018},
issn = {17264189},
journal = {Biogeosciences},
number = {23},
pages = {7155--7175},
title = {{Bipolar carbon and hydrogen isotope constraints on the Holocene methane budget}},
volume = {15},
year = {2018}
}
@article{Bednarsek2020,
author = {Bednar{\v{s}}ek, Nina and Feely, Richard A. and Beck, Marcus W. and Alin, Simone R. and Siedlecki, Samantha A. and Calosi, Piero and Norton, Emily L. and Saenger, Casey and {\v{S}}trus, Jasna and Greeley, Dana and Nezlin, Nikolay P. and Roethler, Miranda and Spicer, John I.},
doi = {10.1016/j.scitotenv.2020.136610},
issn = {00489697},
journal = {Science of The Total Environment},
month = {may},
pages = {136610},
title = {{Exoskeleton dissolution with mechanoreceptor damage in larval Dungeness crab related to severity of present-day ocean acidification vertical gradients}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0048969720301200},
volume = {716},
year = {2020}
}
@article{Beer2010,
author = {Beer, Christian and Reichstein, Markus and Tomelleri, Enrico and Ciais, Philippe and Jung, Martin and Carvalhais, Nuno and Rodenbeck, C. and Arain, M. A. and Baldocchi, D. and Bonan, G. B. and Bondeau, A. and Cescatti, A. and Lasslop, G. and Lindroth, A. and Lomas, M. and Luyssaert, S. and Margolis, H. and Oleson, K. W. and Roupsard, O. and Veenendaal, E. and Viovy, N. and Williams, C. and Woodward, F. I. and Papale, D.},
doi = {10.1126/science.1184984},
issn = {0036-8075},
journal = {Science},
month = {aug},
number = {5993},
pages = {834--838},
title = {{Terrestrial Gross Carbon Dioxide Uptake: Global Distribution and Covariation with Climate}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.1184984},
volume = {329},
year = {2010}
}
@article{Beerling2018,
abstract = {The magnitude of future climate change could be moderated by immediately reducing the amount of CO2 entering the atmosphere as a result of energy generation and by adopting strategies that actively remove CO2 from it. Biogeochemical improvement of soils by adding crushed, fast-reacting silicate rocks to croplands is one such CO2-removal strategy. This approach has the potential to improve crop production, increase protection from pests and diseases, and restore soil fertility and structure. Managed croplands worldwide are already equipped for frequent rock dust additions to soils, making rapid adoption at scale feasible, and the potential benefits could generate financial incentives for widespread adoption in the agricultural sector. However, there are still obstacles to be surmounted. Audited field-scale assessments of the efficacy of CO2 capture are urgently required together with detailed environmental monitoring. A cost-effective way to meet the rock requirements for CO2 removal must be found, possibly involving the recycling of silicate waste materials. Finally, issues of public perception, trust and acceptance must also be addressed.},
author = {Beerling, David J and Leake, Jonathan R and Long, Stephen P and Scholes, Julie D and Ton, Jurriaan and Nelson, Paul N and Bird, Michael and Kantzas, Euripides and Taylor, Lyla L and Sarkar, Binoy and Kelland, Mike and DeLucia, Evan and Kantola, Ilsa and M{\"{u}}ller, Christoph and Rau, Greg and Hansen, James},
doi = {10.1038/s41477-018-0108-y},
issn = {2055-0278},
journal = {Nature Plants},
month = {mar},
number = {3},
pages = {138--147},
title = {{Farming with crops and rocks to address global climate, food and soil security}},
url = {https://doi.org/10.1038/s41477-018-0108-y http://www.nature.com/articles/s41477-018-0108-y},
volume = {4},
year = {2018}
}
@article{BENANTI201482,
author = {Benanti, Giuseppe and Saunders, Matthew and Tobin, Brian and Osborne, Bruce},
doi = {10.1016/j.agrformet.2014.07.014},
issn = {01681923},
journal = {Agricultural and Forest Meteorology},
keywords = {CH,European ash,Gley soils,Greenhouse gas budgets,NO,Sitka spruce},
month = {nov},
pages = {82--93},
title = {{Contrasting impacts of afforestation on nitrous oxide and methane emissions}},
url = {http://www.sciencedirect.com/science/article/pii/S0168192314001816 https://linkinghub.elsevier.com/retrieve/pii/S0168192314001816},
volume = {198-199},
year = {2014}
}
@article{Bennedsen2019,
abstract = {Is the fraction of anthropogenically released CO2 that remains in the atmosphere (the airborne fraction) increasing? Is the rate at which the ocean and land sinks take up CO2 from the atmosphere decreasing? We analyse these questions by means of a statistical dynamic multivariate model from which we estimate the unobserved trend processes together with the parameters that govern them. We show how the concept of a global carbon budget can be used to obtain two separate data series measuring the same physical object of interest, such as the airborne fraction. Incorporating these additional data into the dynamic multivariate model increases the number of available observations, thus improving the reliability of trend and parameter estimates. We find no statistical evidence of an increasing airborne fraction, but we do find statistical evidence of a decreasing sink rate. We infer that the efficiency of the sinks in absorbing CO2 from the atmosphere is decreasing at approximately 0:54{\%}yr-1.},
author = {Bennedsen, Mikkel and Hillebrand, Eric and {Jan Koopman}, Siem},
doi = {10.5194/bg-16-3651-2019},
issn = {17264189},
journal = {Biogeosciences},
number = {18},
pages = {3651--3663},
title = {{Trend analysis of the airborne fraction and sink rate of anthropogenically released CO2}},
volume = {16},
year = {2019}
}
@article{Berchet2016,
abstract = {Abstract. Subsea permafrost and hydrates in the East Siberian Arctic Shelf (ESAS) constitute a substantial carbon pool, and a potentially large source of methane to the atmosphere. Previous studies based on interpolated oceanographic campaigns estimated atmospheric emissions from this area at 8–17 TgCH4 yr−1. Here, we propose insights based on atmospheric observations to evaluate these estimates. The comparison of high-resolution simulations of atmospheric methane mole fractions to continuous methane observations during the whole year 2012 confirms the high variability and heterogeneity of the methane releases from ESAS. A reference scenario with ESAS emissions of 8 TgCH4 yr−1, in the lower part of previously estimated emissions, is found to largely overestimate atmospheric observations in winter, likely related to overestimated methane leakage through sea ice. In contrast, in summer, simulations are more consistent with observations. Based on a comprehensive statistical analysis of the observations and of the simulations, annual methane emissions from ESAS are estimated to range from 0.0 to 4.5 TgCH4 yr−1. Isotopic observations suggest a biogenic origin (either terrestrial or marine) of the methane in air masses originating from ESAS during late summer 2008 and 2009.},
author = {Berchet, Antoine and Bousquet, Philippe and Pison, Isabelle and Locatelli, Robin and Chevallier, Fr{\'{e}}d{\'{e}}ric and Paris, Jean-Daniel and Dlugokencky, Ed J. and Laurila, Tuomas and Hatakka, Juha and Viisanen, Yrjo and Worthy, Doug E. J. and Nisbet, Euan and Fisher, Rebecca and France, James and Lowry, David and Ivakhov, Viktor and Hermansen, Ove},
doi = {10.5194/acp-16-4147-2016},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {mar},
number = {6},
pages = {4147--4157},
title = {{Atmospheric constraints on the methane emissions from the East Siberian Shelf}},
url = {https://acp.copernicus.org/articles/16/4147/2016/},
volume = {16},
year = {2016}
}
@article{Bereiter2018,
abstract = {Little is known about the ocean temperature's long-term response to climate perturbations owing to limited observations and a lack of robust reconstructions. Although most of the anthropogenic heat added to the climate system has been taken up by the ocean up until now, its role in a century and beyond is uncertain. Here, using noble gases trapped in ice cores, we show that the mean global ocean temperature increased by 2.57 ± 0.24 degrees Celsius over the last glacial transition (20,000 to 10,000 years ago). Our reconstruction provides unprecedented precision and temporal resolution for the integrated global ocean, in contrast to the depth-, region-, organism- and season-specific estimates provided by other methods. We find that the mean global ocean temperature is closely correlated with Antarctic temperature and has no lead or lag with atmospheric CO 2, thereby confirming the important role of Southern Hemisphere climate in global climate trends. We also reveal an enigmatic 700-year warming during the early Younger Dryas period (about 12,000 years ago) that surpasses estimates of modern ocean heat uptake.},
author = {Bereiter, Bernhard and Shackleton, Sarah and Baggenstos, Daniel and Kawamura, Kenji and Severinghaus, Jeff},
doi = {10.1038/nature25152},
issn = {0028-0836},
journal = {Nature},
month = {jan},
number = {7686},
pages = {39--44},
pmid = {29300008},
publisher = {Nature Publishing Group},
title = {{Mean global ocean temperatures during the last glacial transition}},
url = {http://dx.doi.org/10.1038/nature25152 http://www.nature.com/articles/nature25152},
volume = {553},
year = {2018}
}
@article{Berg2016,
abstract = {The response of the terrestrial water cycle to global warming is central to issues including water resources, agriculture and ecosystem health. Recent studies indicate that aridity, defined in terms of atmospheric supply (precipitation, P) and demand (potential evapotranspiration, E p) of water at the land surface, will increase globally in a warmer world. Recently proposed mechanisms for this response emphasize the driving role of oceanic warming and associated atmospheric processes. Here we show that the aridity response is substantially amplified by land-atmosphere feedbacks associated with the land surface's response to climate and CO 2 change. Using simulations from the Global Land Atmosphere Coupling Experiment (GLACE)-CMIP5 experiment, we show that global aridity is enhanced by the feedbacks of projected soil moisture decrease on land surface temperature, relative humidity and precipitation. The physiological impact of increasing atmospheric CO 2 on vegetation exerts a qualitatively similar control on aridity. We reconcile these findings with previously proposed mechanisms by showing that the moist enthalpy change over land is unaffected by the land hydrological response. Thus, although oceanic warming constrains the combined moisture and temperature changes over land, land hydrology modulates the partitioning of this enthalpy increase towards increased aridity.},
author = {Berg, Alexis and Findell, Kirsten and Lintner, Benjamin and Giannini, Alessandra and Seneviratne, Sonia I. and {Van Den Hurk}, Bart and Lorenz, Ruth and Pitman, Andy and Hagemann, Stefan and Meier, Arndt and Cheruy, Fr{\'{e}}d{\'{e}}rique and Ducharne, Agn{\`{e}}s and Malyshev, Sergey and Milly, P. C.D.},
doi = {10.1038/nclimate3029},
issn = {17586798},
journal = {Nature Climate Change},
number = {9},
pages = {869--874},
title = {{Land–atmosphere feedbacks amplify aridity increase over land under global warming}},
volume = {6},
year = {2016}
}
@article{BERINGER2011,
abstract = {We estimate the global bioenergy potential from dedicated biomass plantations in the 21st century under a range of sustainability requirements to safeguard food production, biodiversity and terrestrial carbon storage. We use a process-based model of the land biosphere to simulate rainfed and irrigated biomass yields driven by data from different climate models and combine these simulations with a scenario-based assessment of future land availability for energy crops. The resulting spatial patterns of large-scale lignocellulosic energy crop cultivation are then investigated with regard to their impacts on land and water resources. Calculated bioenergy potentials are in the lower range of previous assessments but the combination of all biomass sources may still provide between 130 and 270 EJ yr−1 in 2050, equivalent to 15–25{\%} of the World's future energy demand. Energy crops account for 20–60{\%} of the total potential depending on land availability and share of irrigated area. However, a full exploitation of these potentials will further increase the pressure on natural ecosystems with a doubling of current land use change and irrigation water demand. Despite the consideration of sustainability constraints on future agricultural expansion the large-scale cultivation of energy crops is a threat to many areas that have already been fragmented and degraded, are rich in biodiversity and provide habitat for many endangered and endemic species.},
author = {Beringer, Tim and Lucht, Wolfgang and Schaphoff, Sibyll},
doi = {10.1111/j.1757-1707.2010.01088.x},
issn = {17571693},
journal = {GCB Bioenergy},
language = {en},
month = {aug},
number = {4},
pages = {299--312},
title = {{Bioenergy production potential of global biomass plantations under environmental and agricultural constraints}},
url = {http://doi.wiley.com/10.1111/j.1757-1707.2010.01088.x},
volume = {3},
year = {2011}
}
@article{Betts2018,
abstract = {In early 2016, we predicted that the annual rise in carbon dioxide concentration at Mauna Loa would be the largest on record. Our forecast used a statistical relationship between observed and forecast sea surface temperatures in the Ni{\~{n}}o 3.4 region and the annual CO2 rise. Here, we provide a formal verification of that forecast. The observed rise of 3.4 ppm relative to 2015 was within the forecast range of 3.15 + 0.53 ppm, so the prediction was successful. A global terrestrial biosphere model supports the expectation that the El Ni{\~{n}}o weakened the tropical land carbon sink. We estimate that the El Ni{\~{n}}o contributed approximately 25{\%} to the record rise in CO2, with 75{\%} due to anthropogenic emissions. The 2015/2016 CO2 rise was greater than that following the previous large El Ni{\~{n}}o in 1997/1998, because anthropogenic emissions had increased. We had also correctly predicted that 2016 would be the first year with monthly mean CO2 above 400 ppm all year round. We now estimate that atmospheric CO2 at Mauna Loa would have remained above 400 ppm all year round in 2016 even if the El Ni{\~{n}}o had not occurred, contrary to our previous expectations based on a simple extrapolation of previous trends. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Ni{\~{n}}o on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.},
author = {Betts, Richard A. and Jones, Chris D. and Knight, Jeff R. and Keeling, Ralph F. and Kennedy, John J. and Wiltshire, Andrew J. and Andrew, Robbie M. and Arag{\~{a}}o, Luiz E. O. C.},
doi = {10.1098/rstb.2017.0301},
issn = {0962-8436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
keywords = {Carbon dioxide rise,El Ni{\~{n}}o,Emissions,Mauna Loa,Seasonal forecast,Terrestrial biosphere},
month = {nov},
number = {1760},
pages = {20170301},
title = {{A successful prediction of the record CO2 rise associated with the 2015/2016 El Ni{\~{n}}o}},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2017.0301},
volume = {373},
year = {2018}
}
@techreport{BGR2019,
address = {Hannover, Germany},
author = {BGR},
isbn = {9783981410877},
pages = {200},
title = {{BGR Energy Study 2019 – Data and Developments Concerning German and Global Energy Supplies}},
url = {https://www.bgr.bund.de/EN/Themen/Energie/Produkte/energy{\_}study{\_}2019{\_}summary{\_}en.html},
year = {2020}
}
@article{Bianchi2012,
abstract = {Oxygen minimum zones (OMZs) are major sites of fixed nitrogen removal from the open ocean. However, commonly used gridded data sets such as the World Ocean Atlas (WOA) tend to overestimate the concentration of O2 compared to measurements in grids where O2 falls in the suboxic range (O2 {\textless} 2?10 mmol m?3), thereby underestimating the extent of O2 depletion in OMZs. We evaluate the distribution of the OMZs by (1) mapping high-quality oxygen measurements from the WOCE program, and (2) by applying an empirical correction to the gridded WOA based on in situ observations. The resulting suboxic volumes are a factor 3 larger than in the uncorrected gridded WOA. We combine the new oxygen data sets with estimates of global export and simple models of remineralization to estimate global denitrification and N2O production. We obtain a removal of fixed nitrogen of 70 ± 50 Tg year?1 in the open ocean and 198 ± 64 Tg year?1 in the sediments, and a global N2O production of 6.2 ± 3.2 Tg year?1. Our results (1) reconcile water column denitrification rates based on global oxygen distributions with previous estimates based on nitrogen isotopes, (2) revise existing estimates of sediment denitrification down by 1/3d through the use of spatially explicit fluxes, and (3) provide independent evidence supporting the idea of a historically balanced oceanic nitrogen cycle. These estimates are most sensitive to uncertainties in the global export production, the oxygen threshold for suboxic processes, and the efficiency of particle respiration under suboxic conditions. Ocean deoxygenation, an expected response to anthropogenic climate change, could increase denitrification by 14 Tg year?1 of nitrogen per 1 mmol m?3 of oxygen reduction if uniformly distributed, while leaving N2O production relatively unchanged.},
annote = {doi: 10.1029/2011GB004209},
author = {Bianchi, Daniele and Dunne, John P and Sarmiento, Jorge L and Galbraith, Eric D},
doi = {10.1029/2011GB004209},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {denitrification,nitrogen cycle,suboxia},
month = {jun},
number = {2},
pages = {GB2009},
publisher = {Wiley-Blackwell},
title = {{Data-based estimates of suboxia, denitrification, and N2O production in the ocean and their sensitivities to dissolved O2}},
url = {https://doi.org/10.1029/2011GB004209 http://doi.wiley.com/10.1029/2011GB004209},
volume = {26},
year = {2012}
}
@incollection{BindoffN.L.W.W.L.CheungJ.G.KairoJ.AristeguiV.A.GuinderR.HallbergN.HilmiN.JiaoM.S.KarimL.LevinS.ODonoghueS.R.PurcaCuicapusaB.RinkevichT.SugaA.Tagliabue2019,
author = {Bindoff, N.L. and Cheung, W.W.L. and Kairo, J.G. and Ar{\'{i}}stegui, J. and Guinder, V.A. and Hallberg, R. and Hilmi, N. and Jiao, N. and Karim, M.S. and Levin, L. and O'Donoghue, S. and Cuicapusa, S.R. Purca and Rinkevich, B. and Suga, T. and Tagliabue, A. and Williamson, P.},
booktitle = {IPCC Special Report on the Ocean and Cryosphere in a Changing Climate},
doi = {https://www.ipcc.ch/srocc/chapter/chapter-5},
editor = {Pörtner, H.-O. and Roberts, D.C. and Masson-Delmotte, V. and Zhai, P. and Tignor, M. and Poloczanska, E. and Mintenbeck, K. and Alegría, A. and Nicolai, M. and Okem, A. and Petzold, J. and Rama, B. and Weyer, N.M.},
pages = {447--588},
publisher = {In Press},
title = {{Changing Ocean, Marine Ecosystems, and Dependent Communities}},
url = {https://www.ipcc.ch/srocc/chapter/chapter-5},
year = {2019}
}
@article{Blanc-Betes2020,
abstract = {Abstract The potential of large-scale deployment of basalt to reduce N2O emissions from cultivated soils may contribute to climate stabilization beyond the CO2-removal effect from enhanced weathering. We used 3 years of field observations from maize (Zea mays) and miscanthus (Miscanthus × giganteus) to improve the nitrogen (N) module of the DayCent model and evaluate the potential of basalt amendments to reduce N losses and increase yields from two bioenergy crops. We found 20{\%}–60{\%} improvement in our N2O flux estimates over previous model descriptions. Model results predict that the application of basalt would reduce N2O emissions by 16{\%} in maize and 9{\%} in miscanthus. Lower N2O emissions responded to increases in the N2:N2O ratio of denitrification with basalt-induced increases in soil pH, with minor contributions from the impact of P additions (a minor component of some basalts) on N immobilization. The larger reduction of N2O emissions in maize than in miscanthus was likely explained by a synergistic effect between soil pH and N content, leading to a higher sensitivity of the N2:N2O ratio to changes in pH in heavily fertilized maize. Basalt amendments led to modest increases in modeled yields and the nitrogen use efficiency (i.e., fertilizer-N recover in crop production) of maize but did not affect the productivity of miscanthus. However, enhanced soil P availability maintained the long-term productivity of crops with high nutrient requirements. The alleviation of plant P limitation led to enhanced plant N uptake, thereby contributing to lower microbial N availability and N2O emissions from crops with high nutrient requirements. Our results from the improved model suggest that the large-scale deployment of basalt, by reducing N2O fluxes of cropping systems, could contribute to the sustainable intensification of agriculture and enhance the climate mitigation potential of bioenergy with carbon capture and storage strategies.},
author = {Blanc-Betes, Elena and Kantola, Ilsa B and Gomez-Casanovas, Nuria and Hartman, Melennie D and Parton, William J and Lewis, Amy L and Beerling, David J and DeLucia, Evan H},
doi = {10.1111/gcbb.12757},
journal = {GCB Bioenergy},
number = {1},
pages = {224--241},
title = {{In silico assessment of the potential of basalt amendments to reduce N2O emissions from bioenergy crops}},
url = {https://onlinelibrary.wiley.com/doi/10.1111/gcbb.12757},
volume = {13},
year = {2020}
}
@article{Blanchette2016,
abstract = {An industrial process for the selective activation of methane under mild conditions would be highly valuable for controlling emissions to the environment and for utilizing vast new sources of natural gas. The only selective catalysts for methane activation and conversion to methanol under mild conditions are methane monooxygenases (MMOs) found in methanotrophic bacteria; however, these enzymes are not amenable to standard enzyme immobilization approaches. Using particulate methane monooxygenase (pMMO), we create a biocatalytic polymer material that converts methane to methanol. We demonstrate embedding the material within a silicone lattice to create mechanically robust, gas-permeable membranes, and direct printing of micron-scale structures with controlled geometry. Remarkably, the enzymes retain up to 100{\%} activity in the polymer construct. The printed enzyme-embedded polymer motif is highly flexible for future development and should be useful in a wide range of applications, especially those involving gas–liquid reactions.},
author = {Blanchette, Craig D and Knipe, Jennifer M and Stolaroff, Joshuah K and DeOtte, Joshua R and Oakdale, James S and Maiti, Amitesh and Lenhardt, Jeremy M and Sirajuddin, Sarah and Rosenzweig, Amy C and Baker, Sarah E},
doi = {10.1038/ncomms11900},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {11900},
title = {{Printable enzyme-embedded materials for methane to methanol conversion}},
url = {https://doi.org/10.1038/ncomms11900},
volume = {7},
year = {2016}
}
@article{Bobich2010,
abstract = {The means by which growth CO2 concentration ([CO2]) affects anatomy and water relations responses to drought and vapour pressure deficit (VPD) were studied for yearly coppiced, 4-year-old Populus deltoides clones that were grown in either 400 $\mu$mol mol-1 (ambient) or 800 $\mu$mol mol-1 (elevated) CO2 for 3 years. It was hypothesized that, during drought, trees growing in elevated [CO2] would have a lower volume flux density of water (JV), stomatal conductance (gs) and transpiration per leaf area (E), as well as a lower stomatal density and a greater stomatal response to drought and changes in VPD than would trees in ambient [CO2]. Trees in elevated [CO2] actually had higher JV values throughout the study, but did not differ from trees in ambient [CO2] with respect to gs or E under saturating light or E scaled from JV (Escaled), all of which indicates that the higher JV in elevated [CO 2] resulted from those trees having greater leaf area and not from differences in gs. Furthermore, although plants in elevated [CO2] had greater absolute leaf loss during the drought, the percentage of leaf area lost was similar to that of trees in ambient [CO2]. gs and E under saturating light were affected by changes in VPD after the first 9 days of the experiment, which coincided with a large decrease in water potential at a soil depth of 0.1 m. Trees in elevated [CO2] had a greater stomatal density and a lower wood density than trees in ambient [CO2], both traits that may make the trees more susceptible to xylem cavitation in severe drought. Drought and VPD effects for the P. deltoides clone were not ameliorated by long-term growth in elevated [CO2] compared with ambient [CO 2], and plants in elevated [CO2] possessed anatomical traits that may result in greater stress associated with long-term drought. {\textcopyright} The Author 2010. Published by Oxford University Press. All rights reserved.},
author = {Bobich, Edward G. and Barron-Gafford, Greg A. and Rascher, Katherine G. and Murthy, Ramesh},
doi = {10.1093/treephys/tpq036},
issn = {0829318X},
journal = {Tree Physiology},
keywords = {cottonwood,stomatal conductance,stomatal density,transpiration,volume flux density,wood density},
number = {7},
pages = {866--875},
pmid = {20462939},
title = {{Effects of drought and changes in vapour pressure deficit on water relations of Populus deltoides growing in ambient and elevated CO2}},
volume = {30},
year = {2010}
}
@article{BockE5778,
abstract = {Polar ice is a unique archive of past atmosphere. Here, we present methane stable isotope records (used as source fingerprint) for the current and two past interglacials and their preceding glacial maxima. Our data are used to constrain global emissions of methane. Tropical wetlands and floodplains seem to be the dominant sources of atmospheric methane changes, steered by past variations in sea level, monsoon intensity, temperature, and the water table. In contrast, geologic emissions of methane are stable over a wide range of climatic conditions. The long-term shift seen in both isotopes for the last 25,000 y compared with older intervals is likely connected to changes in the terrestrial biosphere and fire regimes as a consequence of megafauna extinction.Atmospheric methane (CH4) records reconstructed from polar ice cores represent an integrated view on processes predominantly taking place in the terrestrial biogeosphere. Here, we present dual stable isotopic methane records [$\delta$13CH4 and $\delta$D(CH4)] from four Antarctic ice cores, which provide improved constraints on past changes in natural methane sources. Our isotope data show that tropical wetlands and seasonally inundated floodplains are most likely the controlling sources of atmospheric methane variations for the current and two older interglacials and their preceding glacial maxima. The changes in these sources are steered by variations in temperature, precipitation, and the water table as modulated by insolation, (local) sea level, and monsoon intensity. Based on our $\delta$D(CH4) constraint, it seems that geologic emissions of methane may play a steady but only minor role in atmospheric CH4 changes and that the glacial budget is not dominated by these sources. Superimposed on the glacial/interglacial variations is a marked difference in both isotope records, with systematically higher values during the last 25,000 y compared with older time periods. This shift cannot be explained by climatic changes. Rather, our isotopic methane budget points to a marked increase in fire activity, possibly caused by biome changes and accumulation of fuel related to the late Pleistocene megafauna extinction, which took place in the course of the last glacial.},
author = {Bock, Michael and Schmitt, Jochen and Beck, Jonas and Seth, Barbara and Chappellaz, J{\'{e}}r{\^{o}}me and Fischer, Hubertus},
doi = {10.1073/pnas.1613883114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {jul},
number = {29},
pages = {E5778--E5786},
publisher = {National Academy of Sciences},
title = {{Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records}},
url = {http://www.pnas.org/content/114/29/E5778 http://www.pnas.org/lookup/doi/10.1073/pnas.1613883114},
volume = {114},
year = {2017}
}
@article{Bock2010,
abstract = {The causes of past changes in the global methane cycle and especially the role of marine methane hydrate (clathrate) destabilization events are a matter of debate. Here we present evidence from the North Greenland Ice Core Project ice core based on the hydrogen isotopic composition of methane [deltaD(CH4)] that clathrates did not cause atmospheric methane concentration to rise at the onset of Dansgaard-Oeschger (DO) events 7 and 8. Box modeling supports boreal wetland emissions as the most likely explanation for the interstadial increase. Moreover, our data show that deltaD(CH4) dropped 500 years before the onset of DO 8, with CH4 concentration rising only slightly. This can be explained by an early climate response of boreal wetlands, which carry the strongly depleted isotopic signature of high-latitude precipitation at that time.},
author = {Bock, Michael and Schmitt, Jochen and M{\"{o}}ller, Lars and Spahni, Renato and Blunier, Thomas and Fischer, Hubertus},
doi = {10.1126/science.1187651},
issn = {1095-9203},
journal = {Science},
month = {jun},
number = {5986},
pages = {1686--9},
pmid = {20576890},
publisher = {American Association for the Advancement of Science},
title = {{Hydrogen isotopes preclude marine hydrate CH4 emissions at the onset of Dansgaard-Oeschger events}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/20576890},
volume = {328},
year = {2010}
}
@misc{Boden2017a,
address = {Oak Ridge, TN, USA},
author = {Boden, T. A. and Marland, G. and Andres, R. J.},
doi = {10.3334/CDIAC/00001_V2017},
publisher = {Carbon Dioxide Information Analysis Center (CDIAC), Oak Ridge National Laboratory (ORNL)},
title = {{Global, Regional, and National Fossil-Fuel CO2 Emissions (1751–2014) (V. 2017)}},
url = {https://cdiac.ess-dive.lbl.gov/trends/emis/overview.html},
year = {2017}
}
@article{Boer2020,
author = {Boer, Matthias M. and {Resco de Dios}, V{\'{i}}ctor and Bradstock, Ross A.},
doi = {10.1038/s41558-020-0716-1},
issn = {1758-6798},
journal = {Nature Climate Change},
month = {mar},
number = {3},
pages = {171--172},
title = {{Unprecedented burn area of Australian mega forest fires}},
url = {https://doi.org/10.1038/s41558-020-0716-1 http://www.nature.com/articles/s41558-020-0716-1},
volume = {10},
year = {2020}
}
@article{Bopp2015,
author = {Bopp, L. and L{\'{e}}vy, M. and Resplandy, L. and Sall{\'{e}}e, J. B.},
doi = {10.1002/2015GL065073},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {aug},
number = {15},
pages = {6416--6423},
title = {{Pathways of anthropogenic carbon subduction in the global ocean}},
url = {http://doi.wiley.com/10.1002/2015GL065073},
volume = {42},
year = {2015}
}
@article{bg-10-6225-2013,
abstract = {Abstract. Ocean ecosystems are increasingly stressed by human-induced changes of their physical, chemical and biological environment. Among these changes, warming, acidification, deoxygenation and changes in primary productivity by marine phytoplankton can be considered as four of the major stressors of open ocean ecosystems. Due to rising atmospheric CO2 in the coming decades, these changes will be amplified. Here, we use the most recent simulations performed in the framework of the Coupled Model Intercomparison Project 5 to assess how these stressors may evolve over the course of the 21st century. The 10 Earth system models used here project similar trends in ocean warming, acidification, deoxygenation and reduced primary productivity for each of the IPCC's representative concentration pathways (RCPs) over the 21st century. For the "business-as-usual" scenario RCP8.5, the model-mean changes in the 2090s (compared to the 1990s) for sea surface temperature, sea surface pH, global O2 content and integrated primary productivity amount to {\&}plus;2.73 (±0.72) °C, −0.33 (±0.003) pH unit, −3.45 (±0.44){\%} and −8.6 (±7.9){\%}, respectively. For the high mitigation scenario RCP2.6, corresponding changes are +0.71 (±0.45) °C, −0.07 (±0.001) pH unit, −1.81 (±0.31){\%} and −2.0 (±4.1){\%}, respectively, illustrating the effectiveness of extreme mitigation strategies. Although these stressors operate globally, they display distinct regional patterns and thus do not change coincidentally. Large decreases in O2 and in pH are simulated in global ocean intermediate and mode waters, whereas large reductions in primary production are simulated in the tropics and in the North Atlantic. Although temperature and pH projections are robust across models, the same does not hold for projections of subsurface O2 concentrations in the tropics and global and regional changes in net primary productivity. These high uncertainties in projections of primary productivity and subsurface oxygen prompt us to continue inter-model comparisons to understand these model differences, while calling for caution when using the CMIP5 models to force regional impact models.},
author = {Bopp, L. and Resplandy, L. and Orr, J. C. and Doney, S. C. and Dunne, J. P. and Gehlen, M. and Halloran, P. and Heinze, C. and Ilyina, T. and S{\'{e}}f{\'{e}}rian, R. and Tjiputra, J. and Vichi, M.},
doi = {10.5194/bg-10-6225-2013},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {10},
pages = {6225--6245},
title = {{Multiple stressors of ocean ecosystems in the 21st century: projections with CMIP5 models}},
url = {https://www.biogeosciences.net/10/6225/2013/ http://www.biogeosciences.net/10/6225/2013/ https://bg.copernicus.org/articles/10/6225/2013/},
volume = {10},
year = {2013}
}
@incollection{Borges2011,
address = {Waltham, MA, USA},
author = {Borges, A.V. and Abril, G.},
booktitle = {Treatise on Estuarine and Coastal Science},
doi = {10.1016/B978-0-12-374711-2.00504-0},
editor = {Wolanski, Eric and McLusky, Donald},
pages = {119--161},
publisher = {Academic Press},
title = {{Carbon Dioxide and Methane Dynamics in Estuaries}},
url = {https://linkinghub.elsevier.com/retrieve/pii/B9780123747112005040},
year = {2011}
}
@article{Boscolo-Galazzo2018,
abstract = {The temperature of seawater can affect marine plankton in various ways, including by affecting rates of metabolic processes. This can change the way carbon and nutrients are fixed and recycled and hence the chemical and biological profile of the water column. A variety of feedbacks on global climate are possible, especially by altering patterns of uptake and return of carbon dioxide to the atmosphere. Here we summarize and synthesize recent studies in the field of ecology, oceanography and ocean carbon cycling pertaining to possible feedbacks involving metabolic processes. By altering the rates of cellular growth and respiration, temperature-dependency may affect nutrient uptake and food demand in plankton and ultimately the equilibrium of pelagic food webs, with cascade effects on the flux of organic carbon between the upper and inner ocean (the “biological carbon pump”) and the global carbon cycle. Insights from modern ecology can be applied to investigate how temperature-dependent changes in ocean biogeochemical cycling over thousands to millions of years may have shaped the long-term evolution of Earth's climate and life. Investigating temperature-dependency over geological time scales, including through globally warm and cold climate states, can help to identify processes that are relevant for a variety of future scenarios.},
author = {Boscolo-Galazzo, F and Crichton, K.A. and Barker, S and Pearson, P.N.},
doi = {10.1016/j.gloplacha.2018.08.017},
issn = {09218181},
journal = {Global and Planetary Change},
keywords = {Biological pump,Carbon cycle,Climate change,Metabolic theory of Ecology,Temperature dependency},
month = {nov},
pages = {201--212},
title = {{Temperature dependency of metabolic rates in the upper ocean: A positive feedback to global climate change?}},
url = {http://www.sciencedirect.com/science/article/pii/S0921818118301905 https://linkinghub.elsevier.com/retrieve/pii/S0921818118301905},
volume = {170},
year = {2018}
}
@article{Boulton:2017,
abstract = {Abstract The future of the Amazon rainforest is unknown due to uncertainties in projected climate change and the response of the forest to this change (forest resiliency). Here, we explore the effect of some uncertainties in climate and land surface processes on the future of the forest, using a perturbed physics ensemble of HadCM3C. This is the first time Amazon forest changes are presented using an ensemble exploring both land vegetation processes and physical climate feedbacks in a fully coupled modelling framework. Under three different emissions scenarios, we measure the change in the forest coverage by the end of the 21st century (the transient response) and make a novel adaptation to a previously used method known as ?dry-season resilience? to predict the long-term committed response of the forest, should the state of the climate remain constant past 2100. Our analysis of this ensemble suggests that there will be a high chance of greater forest loss on longer timescales than is realized by 2100, especially for mid-range and low emissions scenarios. In both the transient and predicted committed responses, there is an increasing uncertainty in the outcome of the forest as the strength of the emissions scenarios increases. It is important to note however, that very few of the simulations produce future forest loss of the magnitude previously shown under the standard model configuration. We find that low optimum temperatures for photosynthesis and a high minimum leaf area index needed for the forest to compete for space appear to be precursors for dieback. We then decompose the uncertainty into that associated with future climate change and that associated with forest resiliency, finding that it is important to reduce the uncertainty in both of these if we are to better determine the Amazon's outcome.},
author = {Boulton, Chris A and Booth, Ben B B and Good, Peter},
doi = {10.1111/gcb.13733},
isbn = {1354-1013},
issn = {13541013},
journal = {Global Change Biology},
keywords = {Amazon rainforest,climate uncertainty,committed},
month = {dec},
number = {12},
pages = {5032--5044},
title = {{Exploring uncertainty of Amazon dieback in a perturbed parameter Earth system ensemble}},
url = {https://doi.org/10.1111/gcb.13733 http://doi.wiley.com/10.1111/gcb.13733},
volume = {23},
year = {2017}
}
@article{Bousquet2006,
author = {Bousquet, P. and Ciais, P. and Miller, J. B. and Dlugokencky, E. J. and Hauglustaine, D. A. and Prigent, C. and {Van der Werf}, G. R. and Peylin, P. and Brunke, E.-G. and Carouge, C. and Langenfelds, R. L. and Lathi{\`{e}}re, J. and Papa, F. and Ramonet, M. and Schmidt, M. and Steele, L. P. and Tyler, S. C. and White, J.},
doi = {10.1038/nature05132},
issn = {0028-0836},
journal = {Nature},
month = {sep},
number = {7110},
pages = {439--443},
title = {{Contribution of anthropogenic and natural sources to atmospheric methane variability}},
url = {http://www.nature.com/articles/nature05132},
volume = {443},
year = {2006}
}
@article{Bowen2010,
abstract = {The Paleocene-Eocene Thermal Maximum (PETM), an approximately 170,000 year long period of global warming about 56 million years ago, has been attributed to the release of thousands of petagrams of reduced carbon into the ocean, atmosphere and biosphere. However, the fate of this excess carbon at the end of the event is poorly constrained:drawdown of atmospheric carbon dioxide has been attributed to an increase in the weathering of silicates or to increased rates of organic carbon burial. Here we develop constraints on the rate of carbon drawdown baesd on rates of carbon isotope change in well-dated marine and terrestrial sediments spanning the event. We find that the rate of recovery is an order of magnitude more rapid than the expected for carbon drawdown by silicate weathering alone. Unless existing estimates of carbon stocks and cycling during this time are widely inaccurate, our results imply that more than 2,000 Pg of carbon were sequestered as organic carbon over 30,000-40,000 years at the end of the PETM. We suggest that the accelerated sequestration of organic carbon could reflect the regrowth of carbon stocks in the biosphere or shallow lithosphere that were released at the onset of the event.},
author = {Bowen, Gabriel J. and Zachos, James C.},
doi = {10.1038/ngeo1014},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {dec},
number = {12},
pages = {866--869},
title = {{Rapid carbon sequestration at the termination of the Palaeocene–Eocene Thermal Maximum}},
url = {http://www.nature.com/articles/ngeo1014},
volume = {3},
year = {2010}
}
@article{Bowman2020,
abstract = {Vegetation fires are an essential component of the Earth system but can also cause substantial economic losses, severe air pollution, human mortality and environmental damage. Contemporary fire regimes are increasingly impacted by human activities and climate change, but, owing to the complex fire–human–climate interactions and incomplete historical or long-term datasets, it is difficult to detect and project fire-regime trajectories. In this Review, we describe recent global and regional trends in fire activity and examine projections for fire regimes in the near future. Although there are large uncertainties, it is likely that the economic and environmental impacts of vegetation fires will worsen as a result of anthropogenic climate change. These effects will be particularly prominent in flammable forests in populated temperate zones, the sparsely inhabited flammable boreal zone and fire-sensitive tropical rainforests, and will contribute to greenhouse gas emissions. The impacts of increased fire activity can be mitigated through effective stewardship of fire regimes, which should be achieved through evidence-based fire management that incorporates indigenous and local knowledge, combined with planning and design of natural and urban landscapes. Increasing transdisciplinary research is needed to fully understand how Anthropocene fire regimes are changing and how humans must adapt.},
author = {Bowman, David M. J. S. and Kolden, Crystal A. and Abatzoglou, John T. and Johnston, Fay H. and van der Werf, Guido R. and Flannigan, Mike},
doi = {10.1038/s43017-020-0085-3},
issn = {2662-138X},
journal = {Nature Reviews Earth {\&} Environment},
month = {oct},
number = {10},
pages = {500--515},
title = {{Vegetation fires in the Anthropocene}},
url = {https://doi.org/10.1038/s43017-020-0085-3 http://www.nature.com/articles/s43017-020-0085-3},
volume = {1},
year = {2020}
}
@article{Boyd2019,
author = {Boyd, Philip W. and Claustre, Herv{\'{e}} and Levy, Marina and Siegel, David A. and Weber, Thomas},
doi = {10.1038/s41586-019-1098-2},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7752},
pages = {327--335},
title = {{Multi-faceted particle pumps drive carbon sequestration in the ocean}},
url = {http://www.nature.com/articles/s41586-019-1098-2},
volume = {568},
year = {2019}
}
@article{ISI:000346513900022,
abstract = {Climate change is altering oceanic conditions in a complex manner, and the concurrent amendment of multiple properties will modify environmental stress for primary producers. So far, global modelling studies have focused largely on how alteration of individual properties will affect marine life. Here, we use global modelling simulations in conjunction with rotated factor analysis to express model projections in terms of regional trends in concomitant changes to biologically influential multi-stressors. Factor analysis demonstrates that regionally distinct patterns of complex oceanic change are evident globally. Preliminary regional assessments using published evidence of phytoplankton responses to complex change reveal a wide range of future responses to interactive multi-stressors with {\textless}20-300{\%} shifts in phytoplankton physiological rates, and many unexplored potential interactions. In a future ocean, provinces will encounter different permutations of change that will probably alter the dominance of key phytoplankton groups and modify regional productivity, ecosystem structure and biogeochemistry. Consideration of regionally distinct multi-stressor patterns can help guide laboratory and field studies as well as the interpretation of interactive multi-stressors in global models.},
author = {Boyd, Philip W and Lennartz, Sinikka T and Glover, David M and Doney, Scott C},
doi = {10.1038/nclimate2441},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jan},
number = {1},
pages = {71--79},
publisher = {Nature Publishing Group},
title = {{Biological ramifications of climate-change-mediated oceanic multi-stressors}},
url = {http://www.nature.com/articles/nclimate2441},
volume = {5},
year = {2015}
}
@article{Boyd2019a,
author = {Boyd, Philip W and Vivian, Chris},
doi = {10.1038/d41586-019-01790-7},
issn = {0028-0836},
journal = {Nature},
month = {jun},
number = {7760},
pages = {155--157},
title = {{Should we fertilize oceans or seed clouds? No one knows}},
url = {http://www.nature.com/articles/d41586-019-01790-7},
volume = {570},
year = {2019}
}
@article{Boysen2017,
abstract = {Massive near‐term greenhouse gas emissions reduction is a precondition for staying “well below 2°C” global warming as envisaged by the Paris Agreement. Furthermore, extensive terrestrial carbon dioxide...In 2015, parties agreed to limit global warming to “well below” 2°C above pre‐industrial levels. However, this requires not only massive near‐term greenhouse gas emissions reductions but also the application...},
author = {Boysen, Lena R. and Lucht, Wolfgang and Gerten, Dieter and Heck, Vera and Lenton, Timothy M. and Schellnhuber, Hans Joachim},
doi = {10.1002/2016EF000469},
issn = {23284277},
journal = {Earth's Future},
language = {en},
month = {may},
number = {5},
pages = {463--474},
title = {{The limits to global-warming mitigation by terrestrial carbon removal}},
url = {http://doi.wiley.com/10.1002/2016EF000469},
volume = {5},
year = {2017}
}
@article{Boysen2017a,
author = {Boysen, Lena R. and Lucht, Wolfgang and Gerten, Dieter},
doi = {10.1111/gcb.13745},
issn = {13541013},
journal = {Global Change Biology},
language = {en},
month = {oct},
number = {10},
pages = {4303--4317},
title = {{Trade-offs for food production, nature conservation and climate limit the terrestrial carbon dioxide removal potential}},
url = {http://doi.wiley.com/10.1111/gcb.13745},
volume = {23},
year = {2017}
}
@techreport{BP2018,
address = {London, UK},
author = {BP},
keywords = {BP2018},
pages = {53},
publisher = {BP},
title = {{BP Statistical Review of World Energy June 2018}},
url = {https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/statistical-review/bp-stats-review-2018-full-report.pdf},
year = {2018}
}
@article{Brady2020,
abstract = {The California Current System (CCS) sustains economically valuable fisheries and is particularly vulnerable to ocean acidification, due to its natural upwelling of carbon-enriched waters that generate corrosive conditions for local ecosystems. Here we use a novel suite of retrospective, initialized ensemble forecasts with an Earth system model (ESM) to predict the evolution of surface pH anomalies in the CCS. We show that the forecast system skillfully predicts observed surface pH variations a year in advance over a naive forecasting method, with the potential for skillful prediction up to five years in advance. Skillful predictions of surface pH are mainly derived from the initialization of dissolved inorganic carbon anomalies that are subsequently transported into the CCS. Our results demonstrate the potential for ESMs to provide skillful predictions of ocean acidification on large scales in the CCS. Initialized ESMs could also provide boundary conditions to improve high-resolution regional forecasting systems.},
author = {Brady, Riley X. and Lovenduski, Nicole S. and Yeager, Stephen G. and Long, Matthew C. and Lindsay, Keith},
doi = {10.1038/s41467-020-15722-x},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {2166},
pmid = {32358499},
title = {{Skillful multiyear predictions of ocean acidification in the California Current System}},
url = {http://www.nature.com/articles/s41467-020-15722-x},
volume = {11},
year = {2020}
}
@article{Bralower2018,
abstract = {A transect of paleoshelf cores from Maryland and New Jersey contains an {\~{}}0.19- to 1.61-m-thick interval with reduced percentages of carbonate during the onset of the Paleocene-Eocene Thermal Maximum (PETM). Outer paleoshelf cores are barren of nannofossils and correspond to two minor disconformities. Middle paleoshelf cores contain a mixture of samples devoid of nannofossils and those with rare specimens characterized by significant dissolution (i.e., etching). The magnitude of the decrease in carbonate cannot be explained by dilution by clastic material or dissolution resulting from the oxidation of organic matter during early diagenesis. The observed preservation pattern implies a shoaling of the calcite compensation depth and lysocline to the middle shelf. This reduced carbonate interval is observed during the onset of the PETM on other continental margins raising the possibility that extreme shoaling of the calcite compensation depth and lysocline was a global signal, which is more significant than in previous estimates for the PETM. An alternative scenario is that shoaling was restricted to the northwest Atlantic, enhanced by regional and local factors (eutrophication from rivers and microbial activity associated with warming) that exacerbated the impact of acidification on the shelf.},
author = {Bralower, Timothy J. and Kump, Lee R. and Self-Trail, Jean M. and Robinson, Marci M. and Lyons, Shelby and Babila, Tali and Ballaron, Edward and Freeman, Katherine H. and Hajek, Elizabeth and Rush, William and Zachos, James C.},
doi = {10.1029/2018PA003382},
issn = {25724517},
journal = {Paleoceanography and Paleoclimatology},
month = {dec},
number = {12},
pages = {1408--1426},
title = {{Evidence for shelf acidification during the onset of the Paleocene-Eocene thermal maximum}},
url = {http://doi.wiley.com/10.1029/2018PA003382},
volume = {33},
year = {2018}
}
@article{Brandoeaay1632,
abstract = {Wildfires, exacerbated by extreme weather events and land use, threaten to change the Amazon from a net carbon sink to a net carbon source. Here, we develop and apply a coupled ecosystem-fire model to quantify how greenhouse gas{\{}$\backslash$textendash{\}}driven drying and warming would affect wildfires and associated CO2 emissions in the southern Brazilian Amazon. Regional climate projections suggest that Amazon fire regimes will intensify under both low- and high-emission scenarios. Our results indicate that projected climatic changes will double the area burned by wildfires, affecting up to 16{\%} of the region{\{}$\backslash$textquoteright{\}}s forests by 2050. Although these fires could emit as much as 17.0 Pg of CO2 equivalent to the atmosphere, avoiding new deforestation could cut total net fire emissions in half and help prevent fires from escaping into protected areas and indigenous lands. Aggressive efforts to eliminate ignition sources and suppress wildfires will be critical to conserve southern Amazon forests.},
author = {Brando, P M and Soares-Filho, B and Rodrigues, L and Assun{\c{c}}{\~{a}}o, A and Morton, D and Tuchschneider, D and Fernandes, E C M and Macedo, M N and Oliveira, U and Coe, M T},
doi = {10.1126/sciadv.aay1632},
journal = {Science Advances},
number = {2},
pages = {eaay1632},
publisher = {American Association for the Advancement of Science},
title = {{The gathering firestorm in southern Amazonia}},
url = {https://advances.sciencemag.org/content/6/2/eaay1632},
volume = {6},
year = {2020}
}
@article{Brando6347,
abstract = {Climate change alone is unlikely to drive severe tropical forest degradation in the next few decades, but an alternative process associated with severe weather and forest fires is already operating in southeastern Amazonia. Recent droughts caused greatly elevated fire-induced tree mortality in a fire experiment and widespread regional forest fires that burned 5{\{}$\backslash$textendash{\}}12{\%} of southeastern Amazon forests. These results suggest that feedbacks between fires and extreme climatic conditions could increase the likelihood of an Amazon forest {\{}$\backslash$textquotedblleft{\}}dieback{\{}$\backslash$textquotedblright{\}} in the near-term. To secure the integrity of seasonally dry Amazon forests, efforts to end deforestation must be accompanied by initiatives that reduce the accidental spread of land management fires into neighboring forest reserves and effectively suppress forest fires when they start.Interactions between climate and land-use change may drive widespread degradation of Amazonian forests. High-intensity fires associated with extreme weather events could accelerate this degradation by abruptly increasing tree mortality, but this process remains poorly understood. Here we present, to our knowledge, the first field-based evidence of a tipping point in Amazon forests due to altered fire regimes. Based on results of a large-scale, long-term experiment with annual and triennial burn regimes (B1yr and B3yr, respectively) in the Amazon, we found abrupt increases in fire-induced tree mortality (226 and 462{\%}) during a severe drought event, when fuel loads and air temperatures were substantially higher and relative humidity was lower than long-term averages. This threshold mortality response had a cascading effect, causing sharp declines in canopy cover (23 and 31{\%}) and aboveground live biomass (12 and 30{\%}) and favoring widespread invasion by flammable grasses across the forest edge area (80 and 63{\%}), where fires were most intense (e.g., 220 and 820 kW.m-1). During the droughts of 2007 and 2010, regional forest fires burned 12 and 5{\%} of southeastern Amazon forests, respectively, compared with {\textless}1{\%} in nondrought years. These results show that a few extreme drought events, coupled with forest fragmentation and anthropogenic ignition sources, are already causing widespread fire-induced tree mortality and forest degradation across southeastern Amazon forests. Future projections of vegetation responses to climate change across drier portions of the Amazon require more than simulation of g{\ldots}},
author = {Brando, Paulo Monteiro and Balch, Jennifer K and Nepstad, Daniel C and Morton, Douglas C and Putz, Francis E and Coe, Michael T and Silverio, D. and Macedo, Marcia N and Davidson, Eric A and Nobrega, C. C. and Alencar, Ane and Soares-Filho, Britaldo S},
doi = {10.1073/pnas.1305499111},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {apr},
number = {17},
pages = {6347--6352},
publisher = {National Academy of Sciences},
title = {{Abrupt increases in Amazonian tree mortality due to drought–fire interactions}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1305499111 https://www.pnas.org/content/111/17/6347},
volume = {111},
year = {2014}
}
@article{Brando2019,
abstract = {Tropical woody plants store ∼230 petagrams of carbon (PgC) in their aboveground living biomass. This review suggests that these stocks are currently growing in primary forests at rates that have decreased in recent decades. Droughts are an important mechanism in reducing forest C uptake and stocks by decreasing photosynthesis, elevating tree mortality, increasing autotrophic respiration, and promoting wildfires. Tropical forests were a C source to the atmosphere during the 2015-2016 El Ni{\~{n}}o-related drought, with some estimates suggesting that up to 2.3 PgC were released. With continued climate change, the intensity and frequency of droughts and fires will likely increase. It is unclear at what point the impacts of severe, repeated disturbances by drought and fires could exceed tropical forests' capacity to recover. Although specific threshold conditions beyond which ecosystem properties could lead to alternative stable states are largely unknown, the growing body of scientific evidence points to such threshold conditions becoming more likely as climate and land use change across the tropics. ▪ Droughts have reduced forest carbon uptake and stocks by elevating tree mortality, increasing autotrophic respiration, and promoting wildfires. ▪ Threshold conditions beyond which tropical forests are pushed into alternative stable states are becoming more likely as effects of droughts intensify.},
author = {Brando, Paulo M. and Paolucci, Lucas and Ummenhofer, Caroline C. and Ordway, Elsa M. and Hartmann, Henrik and Cattau, Megan E. and Rattis, Ludmila and Medjibe, Vincent and Coe, Michael T. and Balch, Jennifer},
doi = {10.1146/annurev-earth-082517-010235},
issn = {00846597},
journal = {Annual Review of Earth and Planetary Sciences},
keywords = {Amazon,Congo Basin,Southeast Asia,carbon,climate change,drought,tree mortality,tropical forests},
pages = {555--581},
title = {{Droughts, Wildfires, and Forest Carbon Cycling: A Pantropical Synthesis}},
volume = {47},
year = {2019}
}
@article{Breider2019,
abstract = {Ocean acidification, induced by the increase in anthropogenic CO2 emissions, has a profound impact on marine organisms and biogeochemical processes1. The response of marine microbial activities to ocean acidification might play a crucial role in the future evolution of air–sea fluxes of biogenic gases such as nitrous oxide (N2O), a strong GHG and the dominant stratospheric ozone-depleting substance2. Here, we examine the response of N2O production from nitrification to acidification in a series of incubation experiments conducted in subtropical and subarctic western North Pacific. The experiments show that when pH was reduced, the N2O production rate during nitrification measured at subarctic stations increased significantly while nitrification rates remained stable or decreased. Contrary to previous findings, these results suggest that the effect of ocean acidification on N2O production during nitrification and nitrification rates are probably uncoupled. Collectively, these results suggest that if seawater pH continues to decline at the same rate, ocean acidification could increase marine N2O production during nitrification in the subarctic North Pacific by 185 to 491{\%} by the end of the century.},
author = {Breider, Florian and Yoshikawa, Chisato and Makabe, Akiko and Toyoda, Sakae and Wakita, Masahide and Matsui, Yohei and Kawagucci, Shinsuke and Fujiki, Tetsuichi and Harada, Naomi and Yoshida, Naohiro},
doi = {10.1038/s41558-019-0605-7},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {12},
pages = {954--958},
title = {{Response of N2O production rate to ocean acidification in the western North Pacific}},
url = {https://doi.org/10.1038/s41558-019-0605-7},
volume = {9},
year = {2019}
}
@article{Breitburg2018,
abstract = {Oxygen is fundamental to life. Not only is it essential for the survival of individual animals, but it regulates global cycles of major nutrients and carbon. The oxygen content of the open ocean and coastal waters has been declining for at least the past half-century, largely because of human activities that have increased global temperatures and nutrients discharged to coastal waters. These changes have accelerated consumption of oxygen by microbial respiration, reduced solubility of oxygen in water, and reduced the rate of oxygen resupply from the atmosphere to the ocean interior, with a wide range of biological and ecological consequences. Further research is needed to understand and predict long-term, global- and regional-scale oxygen changes and their effects on marine and estuarine fisheries and ecosystems.},
author = {Breitburg, Denise and Levin, Lisa A. A. and Oschlies, Andreas and Gr{\'{e}}goire, Marilaure and Chavez, Francisco P. P. and Conley, Daniel J. J. and Gar{\c{c}}on, V{\'{e}}ronique and Gilbert, Denis and Guti{\'{e}}rrez, Dimitri and Isensee, Kirsten and Jacinto, Gil S. S. and Limburg, Karin E. E. and Montes, Ivonne and Naqvi, S. W.A. A W.A. A and Pitcher, Grant C. C. and Rabalais, Nancy N. N. and Roman, Michael R. R. and Rose, Kenneth A. A. and Seibel, Brad A. A. and Telszewski, Maciej and Yasuhara, Moriaki and Zhang, Jing},
doi = {10.1126/science.aam7240},
isbn = {1095-9203 (Electronic) 0036-8075 (Linking)},
issn = {0036-8075},
journal = {Science},
month = {jan},
number = {6371},
pages = {eaam7240},
pmid = {29301986},
title = {{Declining oxygen in the global ocean and coastal waters}},
url = {http://science.sciencemag.org/content/359/6371/eaam7240.abstract http://www.sciencemag.org/lookup/doi/10.1126/science.aam7240 https://www.sciencemag.org/lookup/doi/10.1126/science.aam7240},
volume = {359},
year = {2018}
}
@article{Brewer2019,
author = {Brewer, Peter G.},
doi = {10.1029/2018RG000620},
issn = {8755-1209},
journal = {Reviews of Geophysics},
month = {sep},
number = {3},
pages = {1112--1123},
title = {{The Molecular Basis for Understanding the Impacts of Ocean Warming}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018RG000620},
volume = {57},
year = {2019}
}
@article{Bridgham2013,
author = {Bridgham, Scott D. and Cadillo-Quiroz, Hinsby and Keller, Jason K. and Zhuang, Qianlai},
doi = {10.1111/gcb.12131},
issn = {13541013},
journal = {Global Change Biology},
month = {may},
number = {5},
pages = {1325--1346},
title = {{Methane emissions from wetlands: biogeochemical, microbial, and modeling perspectives from local to global scales}},
url = {http://doi.wiley.com/10.1111/gcb.12131},
volume = {19},
year = {2013}
}
@article{Brienen:2015,
abstract = {Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades1,2, with a substantial fraction of this sink probably located in the tropics3, particularly in the Amazon4. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity5. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale1,2, and is contrary to expectations based on models6.},
author = {Brienen, R J W and Phillips, O L and Feldpausch, T R and Gloor, E and Baker, T R and Lloyd, J and Lopez-Gonzalez, G and Monteagudo-Mendoza, A and Malhi, Y and Lewis, S L and {V{\'{a}}squez Martinez}, R. and Alexiades, M and {{\'{A}}lvarez D{\'{a}}vila}, E. and Alvarez-Loayza, P and Andrade, A and Arag{\~{a}}o, L. E. O. C. and Araujo-Murakami, A and Arets, E J M M and Arroyo, L and {Aymard C.}, G. A. and B{\'{a}}nki, O. S. and Baraloto, C and Barroso, J and Bonal, D and Boot, R G A and Camargo, J L C and Castilho, C V and Chama, V and Chao, K J and Chave, J and Comiskey, J A and {Cornejo Valverde}, F and da Costa, L and de Oliveira, E A and {Di Fiore}, A and Erwin, T L and Fauset, S and Forsthofer, M and Galbraith, D R and Grahame, E S and Groot, N and H{\'{e}}rault, B. and Higuchi, N and {Honorio Coronado}, E N and Keeling, H and Killeen, T J and Laurance, W. F. and Laurance, S and Licona, J and Magnussen, W E and Marimon, B S and Marimon-Junior, B H and Mendoza, C and Neill, D A and Nogueira, E M and N{\'{u}}{\~{n}}ez, P. and {Pallqui Camacho}, N C and Parada, A and Pardo-Molina, G and Peacock, J and Pe{\~{n}}a-Claros, M. and Pickavance, G C and Pitman, N C A and Poorter, L and Prieto, A and Quesada, C A and Ram{\'{i}}rez, F. and Ram{\'{i}}rez-Angulo, H. and Restrepo, Z and Roopsind, A and Rudas, A and Salom{\~{a}}o, R. P. and Schwarz, M and Silva, N and Silva-Espejo, J E and Silveira, M and Stropp, J and Talbot, J and ter Steege, H and Teran-Aguilar, J and Terborgh, J and Thomas-Caesar, R and Toledo, M and Torello-Raventos, M and Umetsu, R K and van der Heijden, G M F and van der Hout, P and {Guimar{\~{a}}es Vieira}, I. C. and Vieira, S A and Vilanova, E and Vos, V A and Zagt, R J},
doi = {10.1038/nature14283},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {mar},
number = {7543},
pages = {344--348},
pmid = {25788097},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Long-term decline of the Amazon carbon sink}},
url = {http://dx.doi.org/10.1038/nature14283 http://www.nature.com/articles/nature14283},
volume = {519},
year = {2015}
}
@article{Bronselaer2018a,
author = {Bronselaer, Ben and Zanna, Laure and Munday, David R. and Lowe, Jason},
doi = {10.1007/s00382-017-4041-y},
issn = {0930-7575},
journal = {Climate Dynamics},
month = {oct},
number = {7-8},
pages = {2743--2757},
publisher = {Springer Berlin Heidelberg},
title = {{Southern Ocean carbon–wind stress feedback}},
url = {http://link.springer.com/10.1007/s00382-017-4041-y},
volume = {51},
year = {2018}
}
@article{Bronselaer2020,
author = {Bronselaer, Ben and Zanna, Laure},
doi = {10.1038/s41586-020-2573-5},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7820},
pages = {227--233},
title = {{Heat and carbon coupling reveals ocean warming due to circulation changes}},
url = {http://www.nature.com/articles/s41586-020-2573-5},
volume = {584},
year = {2020}
}
@article{Broucek2014,
abstract = {The aim of this review is to summarize the current knowledge of methane (CH4) production from ruminants. The objectives are to identify the factors affecting CH4 production. Methane is a potent greenhouse gas (GHG). Ruminant livestock constitute worldwide the most important source of anthropogenic emissions of methane. There are two main factors influencing global warming change, an increase in greenhouse gas emissions and depletion of the ozone layer. Methane is associated with both factors. Ruminants (dairy, beef, goats, and sheep) are the main contributors to CH4 production. Their CH4 production is a natural and inevitable outcome of rumen fermentation. Feed is converted into products such as milk and meat. Many factors influence ruminant CH4 production, including level of intake, type and quality of feeds, energy consumption, animal size, growth rate, level of production, and environmental temperature. The methane emissions in dairy cows represent values from 151 to 497 g{\textperiodcentered}day-1. Lactating cows produced more CH4 (354 g{\textperiodcentered}day-1) than dry cows (269 g{\textperiodcentered}day-1) and heifers (223 g{\textperiodcentered}day-1). Dairy ewe generates 8.4 kg{\textperiodcentered}head-1 annually. Holstein produced more CH4 (299 g{\textperiodcentered}day-1) than the Crossbred (264 g{\textperiodcentered}day-1). Methane emission by heifers grazing on fertilized pasture was higher (223 g{\textperiodcentered}day-1) than that of heifers on unfertilized pasture (179 g{\textperiodcentered}day-1). The average CH4 emissions are from 161 g{\textperiodcentered}day-1 to 323 g{\textperiodcentered}day-1 in beef cattle. Mature beef cows emit CH4 approximately from 240 g{\textperiodcentered}day-1 to 396 g{\textperiodcentered}day-1. Suffolk sheep emit 22 - 25 g{\textperiodcentered}day-1. The bison's annual CH4 emissions per year were 72 kg{\textperiodcentered}head-1. The CH4 emission from manure depends on the physical form of the feces, the amount of digestible material, the climate, and the time they remained intact. The annual emissions from the pens and storage pond at dairy farm were 120 kg{\textperiodcentered}cow-1.},
author = {Broucek, Jan},
doi = {10.4236/jep.2014.515141},
issn = {2152-2197},
journal = {Journal of Environmental Protection},
number = {15},
pages = {1482--1493},
title = {{Production of Methane Emissions from Ruminant Husbandry: A Review}},
url = {http://www.scirp.org/journal/doi.aspx?DOI=10.4236/jep.2014.515141},
volume = {5},
year = {2014}
}
@article{Brovkin2016,
abstract = {Changes in temperature and carbon dioxide during glacial cycles recorded in Antarctic ice cores are tightly coupled. However, this relationship does not hold for interglacials. While climate cooled towards the end of both the last (Eemian) and present (Holocene) interglacials, CO2remained stable during the Eemian while rising in the Holocene. We identify and review twelve biogeochemical mechanisms of terrestrial (vegetation dynamics and CO2fertilization, land use, wildfire, accumulation of peat, changes in permafrost carbon, subaerial volcanic outgassing) and marine origin (changes in sea surface temperature, carbonate compensation to deglaciation and terrestrial biosphere regrowth, shallow-water carbonate sedimentation, changes in the soft tissue pump, and methane hydrates), which potentially may have contributed to the CO2dynamics during interglacials but which remain not well quantified. We use three Earth System Models (ESMs) of intermediate complexity to compare effects of selected mechanisms on the interglacial CO2and $\delta$13CO2changes, focusing on those with substantial potential impacts: namely carbonate sedimentation in shallow waters, peat growth, and (in the case of the Holocene) human land use. A set of specified carbon cycle forcings could qualitatively explain atmospheric CO2dynamics from 8 ka BP to the pre-industrial. However, when applied to Eemian boundary conditions from 126 to 115 ka BP, the same set of forcings led to disagreement with the observed direction of CO2changes after 122 ka BP. This failure to simulate late-Eemian CO2dynamics could be a result of the imposed forcings such as prescribed CaCO3accumulation and/or an incorrect response of simulated terrestrial carbon to the surface cooling at the end of the interglacial. These experiments also reveal that key natural processes of interglacial CO2dynamics - shallow water CaCO3accumulation, peat and permafrost carbon dynamics - are not well represented in the current ESMs. Global-scale modeling of these long-term carbon cycle components started only in the last decade, and uncertainty in parameterization of these mechanisms is a main limitation in the successful modeling of interglacial CO2dynamics.},
author = {Brovkin, Victor and Br{\"{u}}cher, Tim and Kleinen, Thomas and Zaehle, S{\"{o}}nke and Joos, Fortunat and Roth, Raphael and Spahni, Renato and Schmitt, Jochen and Fischer, Hubertus and Leuenberger, Markus and Stone, Emma J. and Ridgwell, Andy and Chappellaz, J{\'{e}}r{\^{o}}me and Kehrwald, Natalie and Barbante, Carlo and Blunier, Thomas and {Dahl Jensen}, Dorthe},
doi = {10.1016/j.quascirev.2016.01.028},
isbn = {0277-3791},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Carbon cycle,Climate,Coral reef,Fire,Interglacials,Models,Peatland,The Eemian,The Holocene},
month = {apr},
pages = {15--32},
title = {{Comparative carbon cycle dynamics of the present and last interglacial}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379116300300},
volume = {137},
year = {2016}
}
@article{Brovkin2013a,
abstract = {The effects of land-use changes on climate are assessed using specified-concentration simulations com- plementary to the representative concentration pathway 2.6 (RCP2.6) and RCP8.5 scenarios performed for phase 5 of the Coupled Model Intercomparison Project (CMIP5). This analysis focuses on differences in climate and land–atmosphere fluxes between the ensemble averages of simulations with and without land-use changes by the end of the twenty-first century. Even though common land-use scenarios are used, the areas of crops and pastures are specific for each Earth system model (ESM). This is due to different interpretations of land-use classes. The analysis reveals that fossil fuel forcing dominates land-use forcing. In addition, the effects of land-use changes are globally not significant, whereas they are significant for regions with land-use changes exceeding 10{\%}. For these regions, three out of six participating models—the Second Generation Canadian Earth System Model (CanESM2); Hadley Centre Global Environmental Model, version 2 (Earth System) (HadGEM2-ES); and Model for Interdisciplinary Research on Climate, Earth System Model (MIROC-ESM)—reveal statistically significant changes in mean annual surface air temperature. In addition, changes in land surface albedo, available energy, and latent heat fluxes are small but significant for mostESMs in regions affected by land-use changes. These climatic effects are relatively small, as land-use changes in the RCP2.6 and RCP8.5 scenarios are small in magnitude and mainly limited to tropical and subtropical regions. The relative importance of the climatic effects of land-use changes is higher for the RCP2.6 scenario, which considers an expansion of biofuel croplands as a climate mitigation option. The underlying similarity among all models is the loss in global land carbon storage due to land-use changes. 1.},
author = {Brovkin, V. and Boysen, L. and Arora, V. K. and Boisier, J. P. and Cadule, P. and Chini, L. and Claussen, M. and Friedlingstein, P. and Gayler, V. and van den Hurk, B. J. J. M. and Hurtt, G. C. and Jones, C. D. and Kato, E. and de Noblet-Ducoudr{\'{e}}, N. and Pacifico, F. and Pongratz, J. and Weiss, M.},
doi = {10.1175/JCLI-D-12-00623.1},
isbn = {0894-8755},
issn = {0894-8755},
journal = {Journal of Climate},
month = {sep},
number = {18},
pages = {6859--6881},
title = {{Effect of anthropogenic land-use and land-cover changes on climate and land carbon storage in CMIP5 projections for the twenty-first century}},
url = {http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00623.1},
volume = {26},
year = {2013}
}
@article{Brovkin2019,
abstract = {The atmospheric CO2 concentration increased by about 20ppm from 6000BCE to the pre-industrial period (1850CE). Several hypotheses have been proposed to explain mechanisms of this CO2 growth based on either ocean or land carbon sources. Here, we apply the Earth system model MPI-ESM-LR for two transient simulations of climate and carbon cycle dynamics during this period. In the first simulation, atmospheric CO2 is prescribed following ice-core CO2 data. In response to the growing atmospheric CO2 concentration, land carbon storage increases until 2000BCE, stagnates afterwards, and decreases from 1CE, while the ocean continuously takes CO2 out of the atmosphere after 4000BCE. This leads to a missing source of 166Pg of carbon in the ocean-land-atmosphere system by the end of the simulation. In the second experiment, we applied a CO2 nudging technique using surface alkalinity forcing to follow the reconstructed CO2 concentration while keeping the carbon cycle interactive. In that case the ocean is a source of CO2 from 6000 to 2000BCE due to a decrease in the surface ocean alkalinity. In the prescribed CO2 simulation, surface alkalinity declines as well. However, it is not sufficient to turn the ocean into a CO2 source. The carbonate ion concentration in the deep Atlantic decreases in both the prescribed and the interactive CO2 simulations, while the magnitude of the decrease in the prescribed CO2 experiment is underestimated in comparison with available proxies. As the land serves as a carbon sink until 2000BCE due to natural carbon cycle processes in both experiments, the missing source of carbon for land and atmosphere can only be attributed to the ocean. Within our model framework, an additional mechanism, such as surface alkalinity decrease, for example due to unaccounted for carbonate accumulation processes on shelves, is required for consistency with ice-core CO2 data. Consequently, our simulations support the hypothesis that the ocean was a source of CO2 until the late Holocene when anthropogenic CO2 sources started to affect atmospheric CO2.},
author = {Brovkin, Victor and Lorenz, Stephan and Raddatz, Thomas and Ilyina, Tatiana and Stemmler, Irene and Toohey, Matthew and Claussen, Martin},
doi = {10.5194/bg-16-2543-2019},
issn = {17264189},
journal = {Biogeosciences},
number = {13},
pages = {2543--2555},
title = {{What was the source of the atmospheric CO2 increase during the Holocene?}},
volume = {16},
year = {2019}
}
@article{Bruhn2012,
author = {Bruhn, Dan and M{\o}ller, Ian M. and Mikkelsen, Teis N. and Ambus, Per},
doi = {10.1111/j.1399-3054.2011.01551.x},
issn = {00319317},
journal = {Physiologia Plantarum},
month = {mar},
number = {3},
pages = {201--209},
title = {{Terrestrial plant methane production and emission}},
url = {http://doi.wiley.com/10.1111/j.1399-3054.2011.01551.x},
volume = {144},
year = {2012}
}
@article{Bruhwiler2021,
abstract = {Purpose of Review: The Arctic has experienced the most rapid change in climate of anywhere on Earth, and these changes are certain to drive changes in the carbon budget of the Arctic as vegetation changes, soils warm, fires become more frequent, and wetlands evolve as permafrost thaws. In this study, we review the extensive evidence for Arctic climate change and effects on the carbon cycle. In addition, we re-evaluate some of the observational evidence for changing Arctic carbon budgets. Recent Findings: Observations suggest a more active CO2 cycle in high northern latitude ecosystems. Evidence points to increased uptake by boreal forests and Arctic ecosystems, as well as increasing respiration, especially in autumn. However, there is currently no strong evidence of increased CH4 emissions. Summary: Long-term observations using both bottom-up (e.g., flux) and top-down (atmospheric abundance) approaches are essential for understanding changing carbon cycle budgets. Consideration of atmospheric transport is critical for interpretation of top-down observations of atmospheric carbon.},
author = {Bruhwiler, Lori and Parmentier, Frans Jan W. and Crill, Patrick and Leonard, Mark and Palmer, Paul I.},
doi = {10.1007/s40641-020-00169-5},
issn = {21986061},
journal = {Current Climate Change Reports},
keywords = {Arctic,Carbon cycle,Climate change,Methane,Permafrost},
pages = {14--34},
publisher = {Current Climate Change Reports},
title = {{The Arctic Carbon Cycle and Its Response to Changing Climate}},
volume = {7},
year = {2021}
}
@incollection{Brune2018,
address = {Cham, Switzerland},
author = {Brune, Andreas},
booktitle = {Biogenesis of Hydrocarbons},
doi = {10.1007/978-3-319-53114-4_13-1},
editor = {Stams, A. and Sousa, D.},
pages = {1--32},
publisher = {Springer},
title = {{Methanogenesis in the Digestive Tracts of Insects and Other Arthropods}},
url = {http://link.springer.com/10.1007/978-3-319-53114-4{\_}13-1},
year = {2018}
}
@article{Buchanan2016,
abstract = {Abstract. The ocean's ability to store large quantities of carbon, combined with the millennial longevity over which this reservoir is overturned, has implicated the ocean as a key driver of glacial–interglacial climates. However, the combination of processes that cause an accumulation of carbon within the ocean during glacial periods is still under debate. Here we present simulations of the Last Glacial Maximum (LGM) using the CSIRO Mk3L-COAL (Carbon–Ocean–Atmosphere–Land) earth system model to test the contribution of physical and biogeochemical processes to ocean carbon storage. For the LGM simulation, we find a significant global cooling of the surface ocean (3.2 °C) and the expansion of both minimum and maximum sea ice cover broadly consistent with proxy reconstructions. The glacial ocean stores an additional 267 Pg C in the deep ocean relative to the pre-industrial (PI) simulation due to stronger Antarctic Bottom Water formation. However, 889 Pg C is lost from the upper ocean via equilibration with a lower atmospheric CO2 concentration and a global decrease in export production, causing a net loss of carbon relative to the PI ocean. The LGM deep ocean also experiences an oxygenation ( {\textgreater} 100 mmol O2 m−3) and deepening of the calcite saturation horizon (exceeds the ocean bottom) at odds with proxy reconstructions. With modifications to key biogeochemical processes, which include an increased export of organic matter due to a simulated release from iron limitation, a deepening of remineralisation and decreased inorganic carbon export driven by cooler temperatures, we find that the carbon content of the glacial ocean can be sufficiently increased (317 Pg C) to explain the reduction in atmospheric and terrestrial carbon at the LGM (194 ± 2 and 330 ± 400 Pg C, respectively). Assuming an LGM–PI difference of 95 ppm pCO2, we find that 55 ppm can be attributed to the biological pump, 28 ppm to circulation changes and the remaining 12 ppm to solubility. The biogeochemical modifications also improve model–proxy agreement in export production, carbonate chemistry and dissolved oxygen fields. Thus, we find strong evidence that variations in the oceanic biological pump exert a primary control on the climate.},
author = {Buchanan, Pearse J. and Matear, Richard J. and Lenton, Andrew and Phipps, Steven J. and Chase, Zanna and Etheridge, David M.},
doi = {10.5194/cp-12-2271-2016},
issn = {1814-9332},
journal = {Climate of the Past},
month = {dec},
number = {12},
pages = {2271--2295},
title = {{The simulated climate of the Last Glacial Maximum and insights into the global marine carbon cycle}},
url = {https://www.clim-past.net/12/2271/2016/},
volume = {12},
year = {2016}
}
@article{Buermann2018,
abstract = {Climate change is shifting the phenological cycles of plants1, thereby altering the functioning of ecosystems, which in turn induces feedbacks to the climate system2. In northern (north of 30° N) ecosystems, warmer springs lead generally to an earlier onset of the growing season3,4 and increased ecosystem productivity early in the season5. In situ6 and regional7–9 studies also provide evidence for lagged effects of spring warmth on plant productivity during the subsequent summer and autumn. However, our current understanding of these lagged effects, including their direction (beneficial or adverse) and geographic distribution, is still very limited. Here we analyse satellite, field-based and modelled data for the period 1982–2011 and show that there are widespread and contrasting lagged productivity responses to spring warmth across northern ecosystems. On the basis of the observational data, we find that roughly 15 per cent of the total study area of about 41 million square kilometres exhibits adverse lagged effects and that roughly 5 per cent of the total study area exhibits beneficial lagged effects. By contrast, current-generation terrestrial carbon-cycle models predict much lower areal fractions of adverse lagged effects (ranging from 1 to 14 per cent) and much higher areal fractions of beneficial lagged effects (ranging from 9 to 54 per cent). We find that elevation and seasonal precipitation patterns largely dictate the geographic pattern and direction of the lagged effects. Inadequate consideration in current models of the effects of the seasonal build-up of water stress on seasonal vegetation growth may therefore be able to explain the differences that we found between our observation-constrained estimates and the model-constrained estimates of lagged effects associated with spring warming. Overall, our results suggest that for many northern ecosystems the benefits of warmer springs on growing-season ecosystem productivity are effectively compensated for by the accumulation of seasonal water deficits, despite the fact that northern ecosystems are thought to be largely temperature- and radiation-limited10.},
author = {Buermann, Wolfgang and Forkel, Matthias and O'Sullivan, Michael and Sitch, Stephen and Friedlingstein, Pierre and Haverd, Vanessa and Jain, Atul K and Kato, Etsushi and Kautz, Markus and Lienert, Sebastian and Lombardozzi, Danica and Nabel, Julia E M S and Tian, Hanqin and Wiltshire, Andrew J and Zhu, Dan and Smith, William K and Richardson, Andrew D},
doi = {10.1038/s41586-018-0555-7},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7725},
pages = {110--114},
title = {{Widespread seasonal compensation effects of spring warming on northern plant productivity}},
url = {https://doi.org/10.1038/s41586-018-0555-7 http://www.nature.com/articles/s41586-018-0555-7},
volume = {562},
year = {2018}
}
@article{bg-15-2161-2018,
abstract = {Abstract. We estimate the global ocean N2O flux to the atmosphere and its confidence interval using a statistical method based on model perturbation simulations and their fit to a database of $\Delta$pN2O (n = 6136). We evaluate two submodels of N2O production. The first submodel splits N2O production into oxic and hypoxic pathways following previous publications. The second submodel explicitly represents the redox transformations of N that lead to N2O production (nitrification and hypoxic denitrification) and N2O consumption (suboxic denitrification), and is presented here for the first time. We perturb both submodels by modifying the key parameters of the N2O cycling pathways (nitrification rates; NH4+ uptake; N2O yields under oxic, hypoxic and suboxic conditions) and determine a set of optimal model parameters by minimisation of a cost function against four databases of N cycle observations. Our estimate of the global oceanic N2O flux resulting from this cost function minimisation derived from observed and model $\Delta$pN2O concentrations is 2.4±0.8 and 2.5±0.8TgNyr−1 for the two N2O submodels. These estimates suggest that the currently available observational data of surface $\Delta$pN2O constrain the global N2O flux to a narrower range relative to the large range of results presented in the latest IPCC report.},
author = {Buitenhuis, Erik T and Suntharalingam, Parvadha and {Le Qu{\'{e}}r{\'{e}}}, Corinne},
doi = {10.5194/bg-15-2161-2018},
issn = {1726-4189},
journal = {Biogeosciences},
month = {apr},
number = {7},
pages = {2161--2175},
title = {{Constraints on global oceanic emissions of N2O from observations and models}},
url = {https://www.biogeosciences.net/15/2161/2018/},
volume = {15},
year = {2018}
}
@article{Buldovicz2018,
abstract = {Geological activity on icy planets and planetoids includes cryovolcanism. Until recently, most research on terrestrial permafrost has been engineering-oriented, and many related phenomena have received too little attention. Although fast processes in the Earth's cryosphere were known before, they have never been attributed to cryovolcanism. The discovery of a couple of tens of meters wide crater in the Yamal Peninsula aroused numerous hypotheses of its origin, including a meteorite impact or migration of deep gas as a result of global warming. However, the origin of the Yamal crater can be explained in terms of cryospheric processes. Thus, the Yamal crater appears to result from collapse of a large pingo, which formed within a thaw lake when it shoaled and dried out allowing a large talik (that is layer or body of unfrozen ground in a permafrost area) below it to freeze back. The pingo collapsed under cryogenic hydrostatic pressure built up in the closed system of the freezing talik. This happened before the freezing completed, when a core of wet ground remained unfrozen and stored a huge amount of carbon dioxide dissolved in pore water. This eventually reached gas-phase saturation, and the resulting overpressure came to exceed the lithospheric confining stress and the strength of the overlying ice. As the pingo exploded, the demarcation of the crater followed the cylindrical shape of the remnant talik core.},
author = {Buldovicz, Sergey N and Khilimonyuk, Vanda Z and Bychkov, Andrey Y and Ospennikov, Evgeny N and Vorobyev, Sergey A and Gunar, Aleksey Y and Gorshkov, Evgeny I and Chuvilin, Evgeny M and Cherbunina, Maria Y and Kotov, Pavel I and Lubnina, Natalia V and Motenko, Rimma G and Amanzhurov, Ruslan M},
doi = {10.1038/s41598-018-31858-9},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {13534},
title = {{Cryovolcanism on the Earth: Origin of a Spectacular Crater in the Yamal Peninsula (Russia)}},
url = {https://doi.org/10.1038/s41598-018-31858-9},
volume = {8},
year = {2018}
}
@article{Burke:2017,
abstract = {Abstract. An improved representation of the carbon cycle in permafrost regions will enable more realistic projections of the future climate–carbon system. Currently JULES (the Joint UK Land Environment Simulator) – the land surface model of the UK Earth System Model (UKESM) – uses the standard four-pool RothC soil carbon model. This paper describes a new version of JULES (vn4.3{\_}permafrost) in which the soil vertical dimension is added to the soil carbon model, with a set of four pools in every soil layer. The respiration rate in each soil layer depends on the temperature and moisture conditions in that layer. Cryoturbation/bioturbation processes, which transfer soil carbon between layers, are represented by diffusive mixing. The litter inputs and the soil respiration are both parametrized to decrease with increasing depth. The model now includes a tracer so that selected soil carbon can be labelled and tracked through a simulation. Simulations show an improvement in the large-scale horizontal and vertical distribution of soil carbon over the standard version of JULES (vn4.3). Like the standard version of JULES, the vertically discretized model is still unable to simulate enough soil carbon in the tundra regions. This is in part because JULES underestimates the plant productivity over the tundra, but also because not all of the processes relevant for the accumulation of permafrost carbon, such as peat development, are included in the model. In comparison with the standard model, the vertically discretized model shows a delay in the onset of soil respiration in the spring, resulting in an increased net uptake of carbon during this time. In order to provide a more suitable representation of permafrost carbon for quantifying the permafrost carbon feedback within UKESM, the deep soil carbon in the permafrost region (below 1 m) was initialized using the observed soil carbon. There is now a slight drift in the soil carbon ( {\textless} 0.018{\%}decade−1), but the change in simulated soil carbon over the 20th century, when there is little climate change, is comparable to the original vertically discretized model and significantly larger than the drift.},
author = {Burke, Eleanor J and Chadburn, Sarah E and Ekici, Altug},
doi = {10.5194/gmd-10-959-2017},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {feb},
number = {2},
pages = {959--975},
title = {{A vertical representation of soil carbon in the JULES land surface scheme (vn4.3{\_}permafrost) with a focus on permafrost regions}},
url = {https://www.geosci-model-dev.net/10/959/2017/},
volume = {10},
year = {2017}
}
@article{Burke2013,
abstract = {AbstractUnder climate change, thawing permafrost may cause a release of carbon, which has a positive feedback on the climate. The permafrost-carbon climate response ($\gamma$PF) is the additional permafrost-carbon made vulnerable to decomposition per degree of global temperature increase. A simple framework was adopted to estimate $\gamma$PF using the database for phase 5 of the Coupled Model Intercomparison Project (CMIP5). The projected changes in the annual maximum active layer thicknesses (ALTmax) over the twenty-first century were quantified using CMIP5 soil temperatures. These changes were combined with the observed distribution of soil organic carbon and its potential decomposability to give $\gamma$PF. This estimate of $\gamma$PF is dependent on the biases in the simulated present-day permafrost. This dependency was reduced by combining a reference estimate of the present-day ALTmax with an estimate of the sensitivity of ALTmax to temperature from the CMIP5 models. In this case, $\gamma$PF was from −6 to −66 PgC K−1(5th–95th percen...},
author = {Burke, Eleanor J. and Jones, Chris D. and Koven, Charles D.},
doi = {10.1175/JCLI-D-12-00550.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jul},
number = {14},
pages = {4897--4909},
title = {{Estimating the permafrost-carbon climate response in the CMIP5 climate models using a simplified approach}},
url = {http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00550.1},
volume = {26},
year = {2013}
}
@article{bg-14-3051-2017,
abstract = {Abstract. The land surface models JULES (Joint UK Land Environment Simulator, two versions) and ORCHIDEE-MICT (Organizing Carbon and Hydrology in Dynamic Ecosystems), each with a revised representation of permafrost carbon, were coupled to the Integrated Model Of Global Effects of climatic aNomalies (IMOGEN) intermediate-complexity climate and ocean carbon uptake model. IMOGEN calculates atmospheric carbon dioxide (CO2) and local monthly surface climate for a given emission scenario with the land–atmosphere CO2 flux exchange from either JULES or ORCHIDEE-MICT. These simulations include feedbacks associated with permafrost carbon changes in a warming world. Both IMOGEN–JULES and IMOGEN–ORCHIDEE-MICT were forced by historical and three alternative future-CO2-emission scenarios. Those simulations were performed for different climate sensitivities and regional climate change patterns based on 22 different Earth system models (ESMs) used for CMIP3 (phase 3 of the Coupled Model Intercomparison Project), allowing us to explore climate uncertainties in the context of permafrost carbon–climate feedbacks. Three future emission scenarios consistent with three representative concentration pathways were used: RCP2.6, RCP4.5 and RCP8.5. Paired simulations with and without frozen carbon processes were required to quantify the impact of the permafrost carbon feedback on climate change. The additional warming from the permafrost carbon feedback is between 0.2 and 12{\%} of the change in the global mean temperature ($\Delta$T) by the year 2100 and 0.5 and 17{\%} of $\Delta$T by 2300, with these ranges reflecting differences in land surface models, climate models and emissions pathway. As a percentage of $\Delta$T, the permafrost carbon feedback has a greater impact on the low-emissions scenario (RCP2.6) than on the higher-emissions scenarios, suggesting that permafrost carbon should be taken into account when evaluating scenarios of heavy mitigation and stabilization. Structural differences between the land surface models (particularly the representation of the soil carbon decomposition) are found to be a larger source of uncertainties than differences in the climate response. Inertia in the permafrost carbon system means that the permafrost carbon response depends on the temporal trajectory of warming as well as the absolute amount of warming. We propose a new policy-relevant metric – the frozen carbon residence time (FCRt) in years – that can be derived from these complex land surface models and used to quantify the permafrost carbon response given any pathway of global temperature change.},
author = {Burke, Eleanor J and Ekici, Altug and Huang, Ye and Chadburn, Sarah E and Huntingford, Chris and Ciais, Philippe and Friedlingstein, Pierre and Peng, Shushi and Krinner, Gerhard},
doi = {10.5194/bg-14-3051-2017},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jun},
number = {12},
pages = {3051--3066},
title = {{Quantifying uncertainties of permafrost carbon–climate feedbacks}},
url = {https://www.biogeosciences.net/14/3051/2017/},
volume = {14},
year = {2017}
}
@article{Burls2017,
abstract = {An essential element of modern ocean circulation and climate is the Atlantic meridional overturning circulation (AMOC), which includes deep-water formation in the subarctic North Atlantic. However, a comparable overturning circulation is absent in the Pacific, the world's largest ocean, where relatively fresh surface waters inhibit North Pacific deep convection. We present complementary measurement and modeling evidence that the warm, {\~{}}400–ppmv (parts per million by volume) CO2 world of the Pliocene supported subarctic North Pacific deep-water formation and a Pacific meridional overturning circulation (PMOC) cell. In Pliocene subarctic North Pacific sediments, we report orbitally paced maxima in calcium carbonate accumulation rate, with accompanying pigment and total organic carbon measurements supporting deep-ocean ventilation-driven preservation as their cause. Together with high accumulation rates of biogenic opal, these findings require vigorous bidirectional communication between surface waters and interior waters down to {\~{}}3 km in the western subarctic North Pacific, implying deep convection. Redox-sensitive trace metal data provide further evidence of higher Pliocene deep-ocean ventilation before the 2.73-Ma (million years) transition. This observational analysis is supported by climate modeling results, demonstrating that atmospheric moisture transport changes, in response to the reduced meridional sea surface temperature gradients of the Pliocene, were capable of eroding the halocline, leading to deep-water formation in the western subarctic Pacific and a strong PMOC. This second Northern Hemisphere overturning cell has important implications for heat transport, the ocean/atmosphere cycle of carbon, and potentially the equilibrium response of the Pacific to global warming.{\%}U http://advances.sciencemag.org/content/advances/3/9/e1700156.full.pdf},
author = {Burls, Natalie J. and Fedorov, Alexey V. and Sigman, Daniel M. and Jaccard, Samuel L. and Tiedemann, Ralf and Haug, Gerald H.},
doi = {10.1126/sciadv.1700156},
issn = {2375-2548},
journal = {Science Advances},
month = {sep},
number = {9},
pages = {e1700156},
title = {{Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene}},
url = {http://advances.sciencemag.org/content/3/9/e1700156 http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.1700156},
volume = {3},
year = {2017}
}
@article{Burney2010,
abstract = {As efforts to mitigate climate change increase, there is a need to identify cost-effective ways to avoid emissions of greenhouse gases (GHGs). Agriculture is rightly recognized as a source of considerable emissions, with concomitant opportunities for mitigation. Although future agricultural productivity is critical, as it will shape emissions from conversion of native landscapes to food and biofuel crops, investment in agricultural research is rarely mentioned as a mitigation strategy. Here we estimate the net effect on GHG emissions of historical agricultural intensification between 1961 and 2005. We find that while emissions from factors such as fertilizer production and application have increased, the net effect of higher yields has avoided emissions of up to 161 gigatons of carbon (GtC) (590 GtCO2e) since 1961. We estimate that each dollar invested in agricultural yields has resulted in 68 fewer kgC (249 kgCO2e) emissions relative to 1961 technology ({\$}14.74/tC, or ∼{\$}4/tCO2e), avoiding 3.6 GtC (13.1 GtCO2e) per year. Our analysis indicates that investment in yield improvements compares favorably with other commonly proposed mitigation strategies. Further yield improvements should therefore be prominent among efforts to reduce future GHG emissions.},
author = {Burney, Jennifer A. and Davis, Steven J. and Lobell, David B.},
doi = {10.1073/pnas.0914216107},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
language = {en},
month = {jun},
number = {26},
pages = {12052--12057},
title = {{Greenhouse gas mitigation by agricultural intensification}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.0914216107},
volume = {107},
year = {2010}
}
@article{Burton2018a,
abstract = {Abstract The commitment to limit warming to 1.5 °C as set out in the Paris Agreement is widely regarded as ambitious and challenging. It has been proposed that reaching this target may require a number of actions, which could include some form of carbon removal or Solar Radiation Management in addition to strong emission reductions. Here we assess one theoretical solution using Solar Radiation Management to limit global mean warming to 1.5 °C above preindustrial temperatures and use the McArthur fire danger index to evaluate the change in fire danger. The results show that globally fire danger is reduced in most areas when temperatures are limited to 1.5 °C compared to 2.0 °C. The number of days where fire danger is “high” or above is reduced by up to 30 days/year on average, although there are regional variations. In certain regions, fire danger is increased, experiencing 31 more days above “high” fire danger.},
author = {Burton, C and Betts, R A and Jones, C D and Williams, K},
doi = {10.1002/2018GL077848},
journal = {Geophysical Research Letters},
number = {8},
pages = {3644--3652},
title = {{Will Fire Danger Be Reduced by Using Solar Radiation Management to Limit Global Warming to 1.5 °C Compared to 2.0 °C?}},
volume = {45},
year = {2018}
}
@article{Bushinsky2019,
author = {Bushinsky, Seth M. and Landsch{\"{u}}tzer, Peter and R{\"{o}}denbeck, Christian and Gray, Alison R. and Baker, David and Mazloff, Matthew R. and Resplandy, Laure and Johnson, Kenneth S. and Sarmiento, Jorge L.},
doi = {10.1029/2019GB006176},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
month = {nov},
number = {11},
pages = {1370--1388},
title = {{Reassessing Southern Ocean Air-Sea CO2 Flux Estimates With the Addition of Biogeochemical Float Observations}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GB006176},
volume = {33},
year = {2019}
}
@article{Butterbach-Bahl2013,
abstract = {Although it is well established that soils are the dominating source for atmospheric nitrous oxide (N(2)O), we are still struggling to fully understand the complexity of the underlying microbial production and consumption processes and the links to biotic (e.g. inter- and intraspecies competition, food webs, plant–microbe interaction) and abiotic (e.g. soil climate, physics and chemistry) factors. Recent work shows that a better understanding of the composition and diversity of the microbial community across a variety of soils in different climates and under different land use, as well as plant–microbe interactions in the rhizosphere, may provide a key to better understand the variability of N(2)O fluxes at the soil–atmosphere interface. Moreover, recent insights into the regulation of the reduction of N(2)O to dinitrogen (N(2)) have increased our understanding of N(2)O exchange. This improved process understanding, building on the increased use of isotope tracing techniques and metagenomics, needs to go along with improvements in measurement techniques for N(2)O (and N(2)) emission in order to obtain robust field and laboratory datasets for different ecosystem types. Advances in both fields are currently used to improve process descriptions in biogeochemical models, which may eventually be used not only to test our current process understanding from the microsite to the field level, but also used as tools for up-scaling emissions to landscapes and regions and to explore feedbacks of soil N(2)O emissions to changes in environmental conditions, land management and land use.},
author = {Butterbach-Bahl, Klaus and Baggs, Elizabeth M and Dannenmann, Michael and Kiese, Ralf and Zechmeister-Boltenstern, Sophie},
doi = {10.1098/rstb.2013.0122},
issn = {0962-8436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
month = {may},
number = {1621},
pages = {20130122--20130122},
publisher = {The Royal Society},
title = {{Nitrous oxide emissions from soils: how well do we understand the processes and their controls?}},
url = {http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3682742/ http://rstb.royalsocietypublishing.org/cgi/doi/10.1098/rstb.2013.0122},
volume = {368},
year = {2013}
}
@article{Byrne2010,
abstract = {Global ocean acidification is a prominent, inexorable change associated with rising levels of atmospheric CO2. Here we present the first basin-wide direct observations of recently declining pH, along with estimates of anthropogenic and non-anthropogenic contributions to that signal. Along 152°W in the North Pacific Ocean (22–56°N), pH changes between 1991 and 2006 were essentially zero below about 800 m depth. However, in the upper 500 m, significant pH changes, as large as −0.06, were observed. Anthropogenic and non-anthropogenic contributions over the upper 800 m are estimated to be of similar magnitude. In the surface mixed layer (depths to ∼100 m), the extent of pH change is consistent with that expected under conditions of seawater/atmosphere equilibration, with an average rate of change of −0.0017/yr. Future mixed layer changes can be expected to closely mirror changes in atmospheric CO2, with surface seawater pH continuing to fall as atmospheric CO2 rises.},
author = {Byrne, Robert H and Mecking, Sabine and Feely, Richard A and Liu, Xuewu},
doi = {10.1029/2009GL040999},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {jan},
number = {2},
pages = {L02601},
publisher = {Wiley Online Library},
title = {{Direct observations of basin-wide acidification of the North Pacific Ocean}},
url = {http:https://doi.org/10.1029/2009GL040999 http://doi.wiley.com/10.1029/2009GL040999},
volume = {37},
year = {2010}
}
@article{Cabre2015,
author = {Cabr{\'{e}}, Anna and Marinov, Irina and Leung, Shirley},
doi = {10.1007/s00382-014-2374-3},
issn = {0930-7575},
journal = {Climate Dynamics},
month = {sep},
number = {5-6},
pages = {1253--1280},
title = {{Consistent global responses of marine ecosystems to future climate change across the IPCC AR5 earth system models}},
url = {http://link.springer.com/10.1007/s00382-014-2374-3},
volume = {45},
year = {2015}
}
@article{ISI:000296723500014,
abstract = {Human inputs of nutrients to coastal waters can lead to the excessive production of algae, a process known as eutrophication. Microbial consumption of this organic matter lowers oxygen levels in the water(1-3). In addition, the carbon dioxide produced during microbial respiration increases acidity. The dissolution of atmospheric carbon dioxide in ocean waters also raises acidity, a process known as ocean acidification. Here, we assess the combined impact of eutrophication and ocean acidification on acidity in the coastal ocean, using data collected in the northern Gulf of Mexico and the East China Sea-two regions heavily influenced by nutrient-laden rivers. We show that eutrophication in these waters is associated with the development of hypoxia and the acidification of subsurface waters, as expected. Model simulations, using data collected from the northern Gulf of Mexico, however, suggest that the drop in pH since pre-industrial times is greater than that expected from eutrophication and ocean acidification alone. We attribute the additional drop in pH-of 0.05 units-to a reduction in the ability of these carbon dioxide-rich waters to buffer changes in pH. We suggest that eutrophication could increase the susceptibility of coastal waters to ocean acidification.},
author = {Cai, Wei-Jun and Hu, Xinping and Huang, Wei-Jen and Murrell, Michael C. and Lehrter, John C. and Lohrenz, Steven E. and Chou, Wen-Chen and Zhai, Weidong and Hollibaugh, James T. and Wang, Yongchen and Zhao, Pingsan and Guo, Xianghui and Gundersen, Kjell and Dai, Minhan and Gong, Gwo-Ching},
doi = {10.1038/ngeo1297},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {nov},
number = {11},
pages = {766--770},
publisher = {Nature Publishing Group},
title = {{Acidification of subsurface coastal waters enhanced by eutrophication}},
url = {http://www.nature.com/articles/ngeo1297 http://www.readcube.com/articles/10.1038/ngeo1297 http://www.nature.com/doifinder/10.1038/ngeo1297},
volume = {4},
year = {2011}
}
@article{Cai2017c,
abstract = {The combined effects of anthropogenic and biological CO2 inputs may lead to more rapid acidification in coastal waters compared to the open ocean. It is less clear, however, how redox reactions would contribute to acidification. Here we report estuarine acidification dynamics based on oxygen, hydrogen sulfide (H2S), pH, dissolved inorganic carbon and total alkalinity data from the Chesapeake Bay, where anthropogenic nutrient inputs have led to eutrophication, hypoxia and anoxia, and low pH. We show that a pH minimum occurs in mid-depths where acids are generated as a result of H2S oxidation in waters mixed upward from the anoxic depths. Our analyses also suggest a large synergistic effect from river–ocean mixing, global and local atmospheric CO2 uptake, and CO2 and acid production from respiration and other redox reactions. Together they lead to a poor acid buffering capacity, severe acidification and increased carbonate mineral dissolution in the USA's largest estuary.},
author = {Cai, Wei-Jun and Huang, Wei-Jen and Luther, George W and Pierrot, Denis and Li, Ming and Testa, Jeremy and Xue, Ming and Joesoef, Andrew and Mann, Roger and Brodeur, Jean and Xu, Yuan-Yuan and Chen, Baoshan and Hussain, Najid and Waldbusser, George G and Cornwell, Jeffrey and Kemp, W Michael},
doi = {10.1038/s41467-017-00417-7},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {369},
title = {{Redox reactions and weak buffering capacity lead to acidification in the Chesapeake Bay}},
volume = {8},
year = {2017}
}
@article{Cai2020,
abstract = {Syntheses of carbonate chemistry spatial patterns are important for predicting ocean acid-ification impacts, but are lacking in coastal oceans. Here, we show that along the NorthAmerican Atlantic and Gulf coasts the meridional distributions of dissolved inorganic carbon(DIC) and carbonate mineral saturation state ($\Omega$) are controlled by partial equilibrium withthe atmosphere resulting in relatively low DIC and high$\Omega$in warm southern waters and theopposite in cold northern waters. However, pH and the partial pressure of CO2(pCO2) do notexhibit a simple spatial pattern and are controlled by local physical and net biological pro-cesses which impede equilibrium with the atmosphere. Along the Pacific coast, upwellingbrings subsurface waters with low$\Omega$and pH to the surface where net biological productionworks to raise their values. Different temperature sensitivities of carbonate properties anddifferent timescales of influencing processes lead to contrasting property distributions withinand among margins.},
author = {Cai, Wei-Jun and Xu, Yuan-Yuan and Feely, Richard A. and Wanninkhof, Rik and J{\"{o}}nsson, Bror and Alin, Simone R. and Barbero, Leticia and Cross, Jessica N. and Azetsu-Scott, Kumiko and Fassbender, Andrea J. and Carter, Brendan R. and Jiang, Li-Qing and Pepin, Pierre and Chen, Baoshan and Hussain, Najid and Reimer, Janet J. and Xue, Liang and Salisbury, Joseph E. and Hern{\'{a}}ndez-Ay{\'{o}}n, Jos{\'{e}} Mart{\'{i}}n and Langdon, Chris and Li, Qian and Sutton, Adrienne J. and Chen, Chen-Tung A. and Gledhill, Dwight K.},
doi = {10.1038/s41467-020-16530-z},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {2691},
title = {{Controls on surface water carbonate chemistry along North American ocean margins}},
url = {http://www.nature.com/articles/s41467-020-16530-z},
volume = {11},
year = {2020}
}
@article{Cain2019,
abstract = {Anthropogenic global warming at a given time is largely determined by the cumulative total emissions (or stock) of long-lived climate pollutants (LLCPs), predominantly carbon dioxide (CO2), and the emission rates (or flow) of short-lived climate pollutants (SLCPs) immediately prior to that time. Under the United Nations Framework Convention on Climate Change (UNFCCC), reporting of greenhouse gas emissions has been standardised in terms of CO2-equivalent (CO2-e) emissions using Global Warming Potentials (GWP) over 100-years, but the conventional usage of GWP does not adequately capture the different behaviours of LLCPs and SLCPs, or their impact on global mean surface temperature. An alternative usage of GWP, denoted GWP*, overcomes this problem by equating an increase in the emission rate of an SLCP with a one-off “pulse” emission of CO2. We show that this approach, while an improvement on the conventional usage, slightly underestimates the impact of recent increases in SLCP emissions on current rates of warming because the climate does not respond instantaneously to radiative forcing. We resolve this with a modification of the GWP* definition, which incorporates a term for each of the short-timescale and long-timescale climate responses to changes in radiative forcing. The amended version allows “CO2-warming-equivalent” (CO2-we) emissions to be calculated directly from reported emissions. Thus SLCPs can be incorporated directly into carbon budgets consistent with long-term temperature goals, because every unit of CO2-we emitted generates approximately the same amount of warming, whether it is emitted as a SLCP or a LLCP. This is not the case for conventionally derived CO2-e.},
author = {Cain, Michelle and Lynch, John and Allen, Myles R. and Fuglestvedt, Jan S. and Frame, David J. and Macey, Adrian H},
doi = {10.1038/s41612-019-0086-4},
issn = {2397-3722},
journal = {npj Climate and Atmospheric Science},
month = {dec},
pages = {29},
publisher = {Springer Science and Business Media LLC},
title = {{Improved calculation of warming-equivalent emissions for short-lived climate pollutants}},
url = {https://www.nature.com/articles/s41612-019-0086-4},
volume = {2},
year = {2019}
}
@article{Caldeira2003,
author = {Caldeira, Ken and Wickett, Michael E.},
doi = {10.1038/425365a},
issn = {0028-0836},
journal = {Nature},
month = {sep},
number = {6956},
pages = {365--365},
title = {{Anthropogenic carbon and ocean pH}},
url = {http://www.nature.com/articles/425365a},
volume = {425},
year = {2003}
}
@article{Campbell2017,
abstract = {Long-term records of global carbonyl sulfide levels reveal that terrestrial gross primary production (GPP) increased by around 30{\%} during the twentieth century—a finding that may aid understanding of the connection between GPP growth and climate change.},
archivePrefix = {arXiv},
arxivId = {NIHMS150003},
author = {Campbell, J. E. and Berry, J. A. and Seibt, U. and Smith, S. J. and Montzka, S. A. and Launois, T. and Belviso, S. and Bopp, L. and Laine, M.},
doi = {10.1038/nature22030},
eprint = {NIHMS150003},
isbn = {0008-5472 (Print)$\backslash$r0008-5472 (Linking)},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7648},
pages = {84--87},
pmid = {11507039},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Large historical growth in global terrestrial gross primary production}},
url = {http://www.nature.com/doifinder/10.1038/nature22030 http://www.nature.com/articles/nature22030},
volume = {544},
year = {2017}
}
@article{Campbell2018a,
abstract = {The industrial production of long-lived charcoal products (commonly referred to as biochar) from otherwise shorter-lived logging resides (commonly referred to a slash) has been proposed as a means to increasing terrestrial carbon storage thus mitigating global warming caused by anthropogenic greenhouse gas emissions. We present a generalized model that describes the temporal dynamics of biochar carbon stocks, relative to carbon of unmodified logging residue, and evaluate the sensitivity of carbon storage to various biophysical and production parameters. Using this model, we then attribute net carbon storage to several potential biochar production scenarios, specifically engineered to use wood recovered from harvests prescribed to reduce fire hazard in mixed-conifer forests of South-central Oregon. Relative to a baseline scenario where logging residue is left to decay on site, the net carbon storage attributed to 20 years of biochar production is generally negative for the first several decades, then remains positive for several centuries at levels approximately one-fourth the total feedstock carbon processed. Positive net carbon storage and the time required for it to manifest is notably sensitive to biochar conversion efficiencies, logging residue decay rates, and alternate baseline fates of logging residue. The magnitude of net carbon storage, and the time required for it to become positive, is largely similar across range of production facility types. Moreover, the time required for net carbon storage to become positive, and its magnitude over the first 100 years is notably insensitive to biochar decomposition rates provided biochar decays at least ten-times slower than the logging residue it is made from.},
author = {Campbell, John L. and Sessions, John and Smith, David and Trippe, Kristin},
doi = {10.1371/journal.pone.0203475},
issn = {19326203},
journal = {PLOS ONE},
number = {9},
pages = {e0203475},
pmid = {30212474},
title = {{Potential carbon storage in biochar made from logging residue: Basic principles and Southern Oregon case studies}},
volume = {13},
year = {2018}
}
@article{Campos2020,
abstract = {Western Bahia, part of a large Brazilian agricultural frontier, is located mainly in fragile, sandy soils in a tropical seasonal climate with dry winters, characteristics that facilitate soil carbon loss. This study evaluates whether rainfed and irrigated agriculture in Western Bahia were able to sequester carbon and re-establish the soil organic carbon content (SOCC) lost due to land use change. Between 2010 and 2018, a total of 5469 soil samples were collected in the 0.00{\&}ndash;0.20 m soil layer from nine farms and were used to calculate the annual rate of SOCC variation. The most recent SOCC measured in plots where land use change occurred 20 years ago was compared with the SOCC measured in areas of native vegetation (Cerrado). Results showed that (i) irrigated sandy agricultural lands replenished SOCC to the level observed in native vegetation by 20 years after a land use change event and are still capturing carbon at a significant rate, (ii) clayey, rainfed agricultural lands also sequester carbon, but these soils are not representative of the region, and (iii) sandy, rainfed agricultural lands, the predominant soil type and management practice in Western Bahia, are not a sink of CO2.},
author = {Campos, Rafaella and Pires, Gabrielle F and Costa, Marcos H},
doi = {10.3390/agriculture10050156},
isbn = {2077-0472},
journal = {Agriculture},
keywords = {Western Bahia,land use change,sandy soils,soil carbon},
number = {5},
pages = {156},
title = {{Soil Carbon Sequestration in Rainfed and Irrigated Production Systems in a New Brazilian Agricultural Frontier}},
volume = {10},
year = {2020}
}
@article{Cao:2017,
abstract = {Abstract Most modeling studies investigate climate effects of solar geoengineering under prescribed atmospheric CO2, thereby neglecting potential climate feedbacks from the carbon cycle. Here we use an Earth system model to investigate interactive feedbacks between solar geoengineering, global carbon cycle, and climate change. We design idealized sunshade geoengineering simulations to prevent global warming from exceeding 2{\$}\backslash,{\^{}}{\{}\backslashcirc{\}}{\$}C above preindustrial under a CO2 emission scenario with emission mitigation starting from middle of century. By year 2100, solar geoengineering reduces the burden of atmospheric CO2 by 47 PgC with enhanced carbon storage in the terrestrial biosphere. As a result of reduced atmospheric CO2, consideration of the carbon cycle feedback reduces required insolation reduction in 2100 from 2.0 to 1.7 W m?2. With higher climate sensitivity the effect from carbon cycle feedback becomes more important. Our study demonstrates the importance of carbon cycle feedback in climate response to solar geoengineering.},
author = {Cao, Long and Jiang, Jiu},
doi = {10.1002/2017GL076546},
isbn = {0094-8276},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {carbon cycle,climate-carbon,solar geoengineering},
month = {dec},
number = {24},
pages = {12,484--12,491},
title = {{Simulated Effect of Carbon Cycle Feedback on Climate Response to Solar Geoengineering}},
url = {https://doi.org/10.1002/2017GL076546 http://doi.wiley.com/10.1002/2017GL076546},
volume = {44},
year = {2017}
}
@article{ISI:000332072100013,
abstract = {We perform coupled climate-carbon cycle model simulations to examine changes in ocean acidity in response to idealized change of atmospheric CO2. Atmospheric CO2 increases at a rate of 1{\%} per year to four times its pre-industrial level of 280 ppm and then decreases at the same rate to the pre-industrial level. Our simulations show that changes in surface ocean chemistry largely follow changes in atmospheric CO2. However, changes in deep ocean chemistry in general lag behind the change in atmospheric CO2 because of the long time scale associated with the penetration of excess CO2 into the deep ocean. In our simulations with the effect of climate change, when atmospheric CO2 reaches four times its pre-industrial level, global mean aragonite saturation horizon (ASH) shoals from the pre-industrial value of 1288 to 143 m. When atmospheric CO2 returns from the peak value of 1120 ppm to pre-industrial level, ASH is 630 m, which is approximately the value of ASH when atmospheric CO2 first increases to 719 ppm. At pre-industrial CO2 9{\%} deep-sea cold-water corals are surrounded by seawater that is undersaturated with aragonite. When atmospheric CO2 reaches 1120 ppm, 73{\%} cold-water coral locations are surrounded by seawater with aragonite undersaturation, and when atmospheric CO2 returns to the pre-industrial level, 18{\%} cold-water coral locations are surrounded by seawater with aragonite undersaturation. Our analysis indicates the difficulty for some marine ecosystems to recover to their natural chemical habitats even if atmospheric CO2 content can be lowered in the future.},
author = {Cao, Long and Zhang, Han and Zheng, Meidi and Wang, Shuangjing},
doi = {10.1088/1748-9326/9/2/024012},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jan},
number = {2},
pages = {024012},
title = {{Response of ocean acidification to a gradual increase and decrease of atmospheric CO2}},
url = {http://stacks.iop.org/1748-9326/9/i=2/a=024012?key=crossref.fc8ca136a8f558e4fc09a4f2d9730e08},
volume = {9},
year = {2014}
}
@article{Cao2018,
author = {Cao, Long},
doi = {10.1007/s40641-018-0088-z},
issn = {2198-6061},
journal = {Current Climate Change Reports},
month = {mar},
number = {1},
pages = {41--50},
title = {{The Effects of Solar Radiation Management on the Carbon Cycle}},
url = {http://link.springer.com/10.1007/s40641-018-0088-z},
volume = {4},
year = {2018}
}
@article{Cao2020,
abstract = {Cement plays a dual role in the global carbon cycle like a sponge: its massive production contributes significantly to present-day global anthropogenic CO2 emissions, yet its hydrated products gradually reabsorb substantial amounts of atmospheric CO2 (carbonation) in the future. The role of this sponge effect along the cement cycle (including production, use, and demolition) in carbon emissions mitigation, however, remains hitherto unexplored. Here, we quantify the effects of demand- and supply-side mitigation measures considering this material-energy-emissions-uptake nexus, finding that climate goals would be imperiled if the growth of cement stocks continues. Future reabsorption of CO2 will be significant ({\~{}}30{\%} of cumulative CO2 emissions from 2015 to 2100), but climate goal compliant net CO2 emissions reduction along the global cement cycle will require both radical technology advancements (e.g., carbon capture and storage) and widespread deployment of material efficiency measures, which go beyond those envisaged in current technology roadmaps.},
author = {Cao, Zhi and Myers, Rupert J. and Lupton, Richard C. and Duan, Huabo and Sacchi, Romain and Zhou, Nan and {Reed Miller}, T. and Cullen, Jonathan M. and Ge, Quansheng and Liu, Gang},
doi = {10.1038/s41467-020-17583-w},
issn = {20411723},
journal = {Nature Communications},
number = {1},
pages = {1--9},
pmid = {32728073},
publisher = {Springer US},
title = {{The sponge effect and carbon emission mitigation potentials of the global cement cycle}},
url = {http://dx.doi.org/10.1038/s41467-020-17583-w},
volume = {11},
year = {2020}
}
@article{Carstensen2014,
abstract = {Deoxygenation is a global problem in coastal and open regions of the ocean, and has led to expanding areas of oxygen minimum zones and coastal hypoxia. The recent expansion of hypoxia in coastal ecosystems has been primarily attributed to global warming and enhanced nutrient input from land and atmosphere. The largest anthropogenically induced hypoxic area in the world is the Baltic Sea, where the relative importance of physical forcing versus eutrophication is still debated. We have analyzed water column oxygen and salinity profiles to reconstruct oxygen and stratification conditions over the last 115 y and compare the influence of both climate and anthropogenic forcing on hypoxia. We report a 10-fold increase of hypoxia in the Baltic Sea and show that this is primarily linked to increased inputs of nutrients from land, although increased respiration from higher temperatures during the last two decades has contributed to worsening oxygen conditions. Although shifts in climate and physical circulation are important factors modulating the extent of hypoxia, further nutrient reductions in the Baltic Sea will be necessary to reduce the ecosystems impacts of deoxygenation.},
author = {Carstensen, Jacob and Andersen, Jesper H and Gustafsson, Bo G and Conley, Daniel J},
doi = {10.1073/pnas.1323156111},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
keywords = {biogeochemistry,climate change},
month = {apr},
number = {15},
pages = {5628--5633},
pmid = {24706804},
publisher = {National Academy of Sciences},
title = {{Deoxygenation of the Baltic Sea during the last century}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/24706804 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC3992700 http://www.pnas.org/cgi/doi/10.1073/pnas.1323156111},
volume = {111},
year = {2014}
}
@article{Carstensen2019a,
abstract = {A synthesis of long-term changes in pH of coastal ecosystems shows that, in contrast to the uniform trends of open-ocean acidification (−0.0004 to −0.0026 pH units yr–1) driven by increased atmospheric CO2, coastal ecosystems display a much broader range of trends (−0.023 to 0.023 pH units yr–1) and are as likely to show long-term increase as decline in pH. The majority of the 83 investigated coastal ecosystems displayed nonlinear trends, with seasonal and interannual variations exceeding 1 pH unit for some sites. The high pH variability of coastal ecosystems is primarily driven by inputs from land. These include freshwater inputs that typically dilute the alkalinity of seawater thereby resulting in reduced buffering, nutrients enhancing productivity and pH, as well as organic matter supporting excess respiration driving acidification. For some coastal ecosystems, upwelling of nutrient-rich and corrosive water may also contribute to variability in pH. Metabolic control of pH was the main factor governing variability for the majority of coastal sites, displaying larger variations in coastal ecosystems with low alkalinity buffering. pH variability was particularly pronounced in coastal ecosystems with strong decoupling of production and respiration processes, seasonally or through stratification. Our analysis demonstrate that coastal pH can be managed by controlling inputs of nutrients, organic matter, and alkalinity. In well-mixed coastal waters, increasing productivity can improve resistance to ocean acidification, whereas increasing productivity enhances acidification in bottom waters of stratified coastal ecosystems. Environmental management should consider the balance between the negative consequences of eutrophication versus those of acidification, to maintain biodiversity and ecosystem services of our coastal ecosystems.},
annote = {From Duplicate 1 (Drivers of pH Variability in Coastal Ecosystems - Carstensen, Jacob; Duarte, Carlos M)

doi: 10.1021/acs.est.8b03655},
author = {Carstensen, Jacob and Duarte, Carlos M},
doi = {10.1021/acs.est.8b03655},
issn = {0013-936X},
journal = {Environmental Science {\&} Technology},
month = {apr},
number = {8},
pages = {4020--4029},
publisher = {American Chemical Society},
title = {{Drivers of pH variability in coastal ecosystems}},
url = {https://pubs.acs.org/doi/10.1021/acs.est.8b03655},
volume = {53},
year = {2019}
}
@article{Carstensen2019c,
abstract = {Abstract The Baltic Sea is naturally prone to hypoxia, but the frequency and extent have increased multifold over the last century. Hypoxia manifests itself as perennial in the open central part, seasonal at the entrance area, and episodic at many coastal sites, and the expression of hypoxia is largely driven by differences in bottom water residence times and stratification patterns. Enhanced nutrient inputs from land and atmosphere are the main drivers of expanding hypoxia in the Baltic Sea although deoxygenation has also been exacerbated by increasing temperature over the past 3?4 decades. Hypoxia severely influences ecosystem functions such as fish production through reduced trophic efficiency and harmful cyanobacteria blooms sustained by phosphorus release from sediments. Nutrient inputs from land have created the largest man-made hypoxic area in the world and the only viable long-term solution to mitigation is to continue efforts to reduce nutrient loading.},
author = {Carstensen, Jacob and Conley, Daniel J},
doi = {10.1002/lob.10350},
issn = {1539-607X},
journal = {Limnology and Oceanography Bulletin},
month = {nov},
number = {4},
pages = {125--129},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Baltic Sea Hypoxia Takes Many Shapes and Sizes}},
volume = {28},
year = {2019}
}
@article{Cartapanis2018,
abstract = {Abstract. Although it has long been assumed that the glacial–interglacial cycles of atmospheric CO2 occurred due to increased storage of CO2 in the ocean, with no change in the size of the “active” carbon inventory, there are signs that the geological CO2 supply rate to the active pool varied significantly. The resulting changes of the carbon inventory cannot be assessed without constraining the rate of carbon removal from the system, which largely occurs in marine sediments. The oceanic supply of alkalinity is also removed by the burial of calcium carbonate in marine sediments, which plays a major role in air–sea partitioning of the active carbon inventory. Here, we present the first global reconstruction of carbon and alkalinity burial in deep-sea sediments over the last glacial cycle. Although subject to large uncertainties, the reconstruction provides a first-order constraint on the effects of changes in deep-sea burial fluxes on global carbon and alkalinity inventories over the last glacial cycle. The results suggest that reduced burial of carbonate in the Atlantic Ocean was not entirely compensated by the increased burial in the Pacific basin during the last glacial period, which would have caused a gradual buildup of alkalinity in the ocean. We also consider the magnitude of possible changes in the larger but poorly constrained rates of burial on continental shelves, and show that these could have been significantly larger than the deep-sea burial changes. The burial-driven inventory variations are sufficiently large to have significantly altered the $\delta$13C of the ocean–atmosphere carbon and changed the average dissolved inorganic carbon (DIC) and alkalinity concentrations of the ocean by more than 100{\&}thinsp;µM, confirming that carbon burial fluxes were a dynamic, interactive component of the glacial cycles that significantly modified the size of the active carbon pool. Our results also suggest that geological sources and sinks were significantly unbalanced during the late Holocene, leading to a slow net removal flux on the order of 0.1{\&}thinsp;PgC{\&}thinsp;yr−1 prior to the rapid input of carbon during the industrial period. ]]{\textgreater}},
author = {Cartapanis, Olivier and Galbraith, Eric D. and Bianchi, Daniele and Jaccard, Samuel L.},
doi = {10.5194/cp-14-1819-2018},
issn = {1814-9332},
journal = {Climate of the Past},
month = {nov},
number = {11},
pages = {1819--1850},
title = {{Carbon burial in deep-sea sediment and implications for oceanic inventories of carbon and alkalinity over the last glacial cycle}},
url = {https://www.clim-past.net/14/1819/2018/},
volume = {14},
year = {2018}
}
@article{Carter2017,
abstract = {A modified version of the extended multiple linear regression (eMLR) method is used to estimate anthropogenic carbon concentration (Canth) changes along the Pacific P02 and P16 hydrographic sections over the past two decades. P02 is a zonal section crossing the North Pacific at 30°N, and P16 is a meridional section crossing the North and South Pacific at {\~{}}150°W. The eMLR modifications allow the uncertainties associated with choices of regression parameters to be both resolved and reduced. Canth is found to have increased throughout the water column from the surface to {\~{}}1000?m depth along both lines in both decades. Mean column Canth inventory increased consistently during the earlier (1990s?2000s) and recent (2000s?2010s) decades along P02, at rates of 0.53?±?0.11 and 0.46?±?0.11?mol?C?m?2?a?1, respectively. By contrast, Canth storage accelerated from 0.29?±?0.10 to 0.45?±?0.11?mol?C?m?2?a?1 along P16. Shifts in water mass distributions are ruled out as a potential cause of this increase, which is instead attributed to recent increases in the ventilation of the South Pacific Subtropical Cell. Decadal changes along P16 are extrapolated across the gyre to estimate a Pacific Basin average storage between 60°S and 60°N of 6.1?±?1.5?PgC?decade?1 in the earlier decade and 8.8?±?2.2?PgC?decade?1 in the recent decade. This storage estimate is large despite the shallow Pacific Canth penetration due to the large volume of the Pacific Ocean. By 2014, Canth storage had changed Pacific surface seawater pH by ?0.08 to ?0.14 and aragonite saturation state by ?0.57 to ?0.82.},
annote = {From Duplicate 1 (Two decades of Pacific anthropogenic carbon storage and ocean acidification along Global Ocean Ship-based Hydrographic Investigations Program sections P16 and P02 - Carter, B. R.; Feely, R. A.; Mecking, S.; Cross, J. N.; Macdonald, A. M.; Siedlecki, S. A.; Talley, L. D.; Sabine, C. L.; Millero, F. J.; Swift, J. H.; Dickson, A. G.; Rodgers, K. B.)

doi: 10.1002/2016GB005485},
author = {Carter, B. R. and Feely, R. A. and Mecking, S. and Cross, J. N. and Macdonald, A. M. and Siedlecki, S. A. and Talley, L. D. and Sabine, C. L. and Millero, F. J. and Swift, J. H. and Dickson, A. G. and Rodgers, K. B.},
doi = {10.1002/2016GB005485},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {P02 and P16,anthropogenic carbon,decadal variability,eMLR,ocean acidification,repeat hydrography},
month = {feb},
number = {2},
pages = {306--327},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Two decades of Pacific anthropogenic carbon storage and ocean acidification along Global Ocean Ship-based Hydrographic Investigations Program sections P16 and P02}},
url = {http://doi.wiley.com/10.1002/2016GB005485},
volume = {31},
year = {2017}
}
@article{Carter2019,
abstract = {Abstract We estimate anthropogenic carbon (Canth) accumulation rates in the Pacific Ocean between 1991 and 2017 from 14 hydrographic sections that have been occupied two to four times over the past few decades, with most sections having been recently measured as part of the Global Ocean Ship-based Hydrographic Investigations Program. The rate of change of Canth is estimated using a new method that combines the extended multiple linear regression method with improvements to address the challenges of analyzing multiple occupations of sections spaced irregularly in time. The Canth accumulation rate over the top 1,500 m of the Pacific increased from 8.8 (±1.1, 1$\sigma$) Pg of carbon per decade between 1995 and 2005 to 11.7 (±1.1) PgC per decade between 2005 and 2015. For the entire Pacific, about half of this decadal increase in the accumulation rate is attributable to the increase in atmospheric CO2, while in the South Pacific subtropical gyre this fraction is closer to one fifth. This suggests a substantial enhancement of the accumulation of Canth in the South Pacific by circulation variability and implies that a meaningful portion of the reinvigoration of the global CO2 sink that occurred between {\~{}}2000 and {\~{}}2010 could be driven by enhanced ocean Canth uptake and advection into this gyre. Our assessment suggests that the accuracy of Canth accumulation rate reconstructions along survey lines is limited by the accuracy of the full suite of hydrographic data and that a continuation of repeated surveys is a critical component of future carbon cycle monitoring.},
annote = {doi: 10.1029/2018GB006154},
author = {Carter, B R and Feely, R A and Wanninkhof, R and Kouketsu, S and Sonnerup, R E and Pardo, P C and Sabine, C L and Johnson, G C and Sloyan, B M and Murata, A and Mecking, S and Tilbrook, B and Speer, K and Talley, L D and Millero, F J and Wijffels, S E and Macdonald, A M and Gruber, N and Bullister, J L},
doi = {10.1029/2018GB006154},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {Pacific,anthropogenic carbon,decadal variability,eMLR,ocean acidification,repeat hydrography},
month = {may},
number = {5},
pages = {597--617},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Pacific anthropogenic carbon between 1991 and 2017}},
url = {https://doi.org/10.1029/2018GB006154},
volume = {33},
year = {2019}
}
@article{Cavan2019,
author = {Cavan, Emma Louise and Henson, Stephanie A. and Boyd, Philip W.},
doi = {10.3389/fevo.2018.00230},
issn = {2296-701X},
journal = {Frontiers in Ecology and Evolution},
month = {jan},
pages = {230},
title = {{The Sensitivity of Subsurface Microbes to Ocean Warming Accentuates Future Declines in Particulate Carbon Export}},
url = {https://www.frontiersin.org/article/10.3389/fevo.2018.00230/full},
volume = {6},
year = {2019}
}
@article{Cavan2017,
abstract = {Abstract. The efficiency of the ocean's biological carbon pump (BCPeff – here the product of particle export and transfer efficiencies) plays a key role in the air–sea partitioning of CO2. Despite its importance in the global carbon cycle, the biological processes that control BCPeff are poorly known. We investigate the potential role that zooplankton play in the biological carbon pump using both in situ observations and model output. Observed and modelled estimates of fast, slow, and total sinking fluxes are presented from three oceanic sites: the Atlantic sector of the Southern Ocean, the temperate North Atlantic, and the equatorial Pacific oxygen minimum zone (OMZ). We find that observed particle export efficiency is inversely related to primary production likely due to zooplankton grazing, in direct contrast to the model estimates. The model and observations show strongest agreement in remineralization coefficients and BCPeff at the OMZ site where zooplankton processing of particles in the mesopelagic zone is thought to be low. As the model has limited representation of zooplankton-mediated remineralization processes, we suggest that these results point to the importance of zooplankton in setting BCPeff, including particle grazing and fragmentation, and the effect of diel vertical migration. We suggest that improving parameterizations of zooplankton processes may increase the fidelity of biogeochemical model estimates of the biological carbon pump. Future changes in climate such as the expansion of OMZs may decrease the role of zooplankton in the biological carbon pump globally, hence increasing its efficiency.},
author = {Cavan, Emma L. and Henson, Stephanie A. and Belcher, Anna and Sanders, Richard},
doi = {10.5194/bg-14-177-2017},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jan},
number = {1},
pages = {177--186},
title = {{Role of zooplankton in determining the efficiency of the biological carbon pump}},
url = {https://www.biogeosciences.net/14/177/2017/},
volume = {14},
year = {2017}
}
@article{CAYUELA20145,
annote = {Environmental Benefits and Risks of Biochar Application to Soil},
author = {Cayuela, M.L. and van Zwieten, L and Singh, B.P. and Jeffery, S and Roig, A and S{\'{a}}nchez-Monedero, M.A.},
doi = {10.1016/j.agee.2013.10.009},
issn = {01678809},
journal = {Agriculture, Ecosystems {\&} Environment},
keywords = {Charcoal,Greenhouse gas emissions,NO mitigation,Systematic review},
month = {jun},
pages = {5--16},
title = {{Biochar's role in mitigating soil nitrous oxide emissions: A review and meta-analysis}},
url = {http://www.sciencedirect.com/science/article/pii/S0167880913003496 https://linkinghub.elsevier.com/retrieve/pii/S0167880913003496},
volume = {191},
year = {2014}
}
@article{Chan2019a,
author = {Chan, Francis and Barth, John and Kroeker, Kristy and Lubchenco, Jane and Menge, Bruce},
doi = {10.5670/oceanog.2019.312},
issn = {10428275},
journal = {Oceanography},
month = {sep},
number = {3},
pages = {62--71},
title = {{The dynamics and impact of ocean acidification and hypoxia: insights from sustained investigations in the northern California current large marine ecosystem}},
url = {https://tos.org/oceanography/article/the-dynamics-and-impact-of-ocean-acidification-and-hypoxia},
volume = {32},
year = {2019}
}
@article{Chandra2021,
abstract = {Methane (CH4) is an important greenhouse gas and plays a significant role in tropospheric and stratospheric chemistry. Yet, there is no scientific consensus on the causes of the large inter-decadal CH4 growth rate variability. Using a well-validated atmospheric chemistry-transport model, worldwide CH4 measurements and emission inventories by sector, we have estimated CH4 emissions during the period of 1988-2016. We show that reductions in emissions from industrial production in the 1980s and Mt. Pinatubo volcanic eruption in 1991 led to the stabilisation of atmospheric CH4 during the following period. The CH4 regrowth from 2006 has been attributed to increases in emissions mainly from coal industry and ruminant farming. In contrast, interannual variations were primarily driven by natural climate variability. The variability in the inter-polar gradient and the growth rate of CH4 are shown to have a strong link with the temporal evolution and meridional shift of emissions, suggesting a major role of the CH4 loss by hydroxyl (OH) in the inter-decadal trends is unlikely. Our results are further supported by 2-box model simulations of 13C-CH4. No evidence of emission enhancement due to climate warming is observed in the atmospheric CH4 variability.},
author = {Chandra, Naveen and Patra, Prabir K. and Bisht, Jagat S. H. and Ito, Akihiko and Umezawa, Taku and Saigusa, Nobuko and Morimoto, Shinji and Aoki, Shuji and Janssens-Maenhout, Greet and Fujita, Ryo and Takigawa, Masayuki and Watanabe, Shingo and Saitoh, Naoko and Canadell, Josep G.},
doi = {10.2151/jmsj.2021-015},
institution = {JAMSTEC},
issn = {0026-1165},
journal = {Journal of the Meteorological Society of Japan. Series II},
keywords = {CH4 variability,inverse modelling},
language = {L7659},
number = {2},
pages = {309--337},
title = {{Emissions from the Oil and Gas Sectors, Coal Mining and Ruminant Farming Drive Methane Growth over the Past Three Decades}},
url = {https://www.jstage.jst.go.jp/article/jmsj/advpub/0/advpub{\_}2021-015/{\_}article},
volume = {99},
year = {2021}
}
@article{Chang2018,
abstract = {Understanding marine environmental change and associated biological turnover across the Palaeocene–Eocene Thermal Maximum (PETM; {\~{}}56 Ma)—the most pronounced Cenozoic short-term global warming event—is important because of the potential role of the ocean in atmospheric CO2 drawdown, yet proxies for tracing marine productivity and oxygenation across the PETM are limited and results remain controversial. Here we show that a high-resolution record of South Atlantic Ocean bottom water oxygenation can be extracted from exceptionally preserved magnetofossils—the bioinorganic magnetite nanocrystals produced by magnetotactic bacteria (MTB) using a new multiscale environmental magnetic approach. Our results suggest that a transient MTB bloom occurred due to increased nutrient supply. Bottom water oxygenation decreased gradually from the onset to the peak PETM. These observations provide a record of microbial response to the PETM and establish the value of magnetofossils as palaeoenvironmental indicators.},
author = {Chang, Liao and Harrison, Richard J. and Zeng, Fan and Berndt, Thomas A. and Roberts, Andrew P. and Heslop, David and Zhao, Xiang},
doi = {10.1038/s41467-018-06472-y},
issn = {20411723},
journal = {Nature Communications},
number = {1},
pages = {1--9},
pmid = {30275540},
title = {{Coupled microbial bloom and oxygenation decline recorded by magnetofossils during the Palaeocene–Eocene Thermal Maximum}},
volume = {9},
year = {2018}
}
@article{Chaudhary2020,
abstract = {Abstract The majority of northern peatlands were initiated during the Holocene. Owing to their mass imbalance, they have sequestered huge amounts of carbon in terrestrial ecosystems. Although recent syntheses have filled some knowledge gaps, the extent and remoteness of many peatlands pose challenges to developing reliable regional carbon accumulation estimates from observations. In this work, we employed an individual- and patch-based dynamic global vegetation model (LPJ-GUESS) with peatland and permafrost functionality to quantify long-term carbon accumulation rates in northern peatlands and to assess the effects of historical and projected future climate change on peatland carbon balance. We combined published datasets of peat basal age to form an up-to-date peat inception surface for the pan-Arctic region which we then used to constrain the model. We divided our analysis into two parts, with a focus both on the carbon accumulation changes detected within the observed peatland boundary and at pan-Arctic scale under two contrasting warming scenarios (representative concentration pathway?RCP8.5 and RCP2.6). We found that peatlands continue to act as carbon sinks under both warming scenarios, but their sink capacity will be substantially reduced under the high-warming (RCP8.5) scenario after 2050. Areas where peat production was initially hampered by permafrost and low productivity were found to accumulate more carbon because of the initial warming and moisture-rich environment due to permafrost thaw, higher precipitation and elevated CO2 levels. On the other hand, we project that areas which will experience reduced precipitation rates and those without permafrost will lose more carbon in the near future, particularly peatlands located in the European region and between 45 and 55°N latitude. Overall, we found that rapid global warming could reduce the carbon sink capacity of the northern peatlands in the coming decades.},
annote = {doi: 10.1111/gcb.15099},
author = {Chaudhary, Nitin and Westermann, Sebastian and Lamba, Shubhangi and Shurpali, Narasinha and Sannel, A Britta K and Schurgers, Guy and Miller, Paul A and Smith, Benjamin},
doi = {10.1111/gcb.15099},
issn = {1354-1013},
journal = {Global Change Biology},
keywords = {basal age,carbon accumulation,climate change,dynamic global vegetation models (DGVMs),peatland,permafrost},
month = {jul},
number = {7},
pages = {4119--4133},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Modelling past and future peatland carbon dynamics across the pan-Arctic}},
url = {https://doi.org/10.1111/gcb.15099},
volume = {26},
year = {2020}
}
@article{Chavez2008,
author = {Chavez, Francisco P. and Bertrand, Arnaud and Guevara-Carrasco, Renato and Soler, Pierre and Csirke, Jorge},
doi = {10.1016/j.pocean.2008.10.012},
issn = {00796611},
journal = {Progress in Oceanography},
month = {oct},
number = {2-4},
pages = {95--105},
publisher = {Pergamon},
title = {{The northern Humboldt Current System: Brief history, present status and a view towards the future}},
url = {https://www.sciencedirect.com/science/article/pii/S0079661108001651 https://linkinghub.elsevier.com/retrieve/pii/S0079661108001651},
volume = {79},
year = {2008}
}
@article{Chen2017,
abstract = {Oceans worldwide are undergoing acidification due to the penetration of anthropogenic CO2 from the atmosphere1–4. The rate of acidification generally diminishes with increasing depth. Yet, slowing down of the thermohaline circulation due to global warming could reduce the pH in the deep oceans, as more organic material would decompose with a longer residence time. To elucidate this process, a time-series study at a climatically sensitive region with sufficient duration and resolution is needed. Here we show that deep waters in the Sea of Japan are undergoing reduced ventilation, reducing the pH of seawater. As a result, the acidification rate near the bottom of the Sea of Japan is 27{\%} higher than the rate at the surface, which is the same as that predicted assuming an air–sea CO2 equilibrium. This reduced ventilation may be due to global warming and, as an oceanic microcosm with its own deep- and bottom-water formations, the Sea of Japan provides an insight into how future warming might alter the deep-ocean acidification.},
author = {Chen, Chen-Tung Arthur and Lui, Hon-Kit and Hsieh, Chia-Han and Yanagi, Tetsuo and Kosugi, Naohiro and Ishii, Masao and Gong, Gwo-Ching},
doi = {10.1038/s41558-017-0003-y},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {dec},
number = {12},
pages = {890--894},
title = {{Deep oceans may acidify faster than anticipated due to global warming}},
url = {https://doi.org/10.1038/s41558-017-0003-y http://www.nature.com/articles/s41558-017-0003-y},
volume = {7},
year = {2017}
}
@article{Chen2007,
abstract = {Anoxia and hypoxia have been widely observed in estuarine and coastal regions over the past few decades; however, few reports have focused on the East China Sea (ECS). In June and August 2003, two cruises sampled at stations covering almost the entire shelf of the ECS to examine hypoxic events and their potential causes. In August, DO concentrations {\textless}2–3mgl−1 covered an area estimated at greater than 12,000km2 (or 432km3 volume). In contrast, water column DO concentrations exceeded 4mgl−1 throughout most of the shelf region. A sharp density gradient was observed under the mixed layer in August, restricting vertical re-aeration across this strong pycnocline. Oxygen depletion events, such as that described here for the ECS shelf, are fueled by decomposition of newly produced marine and river-borne biogenic substances (as well as older residual organic matter) deposited to the bottom waters.},
author = {Chen, Chung-Chi and Gong, Gwo-Ching and Shiah, Fuh-Kwo},
doi = {10.1016/j.marenvres.2007.01.007},
issn = {01411136},
journal = {Marine Environmental Research},
month = {oct},
number = {4},
pages = {399--408},
publisher = {Elsevier},
title = {{Hypoxia in the East China Sea: One of the largest coastal low-oxygen areas in the world}},
url = {https://www.sciencedirect.com/science/article/pii/S0141113607000414 https://linkinghub.elsevier.com/retrieve/pii/S0141113607000414},
volume = {64},
year = {2007}
}
@article{Chen2019a,
abstract = {Afforestation is of importance for terrestrial carbon sequestration as well as soil and water conservation in karst landscapes. However, few studies have evaluated the effects of afforestation on soil CH4 and N2O emissions in subtropical karst areas. Thus, a year-round field experiment was conducted to quantify the effects of afforestation on soil CH4 and N2O fluxes from a subtropical karst landscape in South China. In this study, soil CH4 and N2O fluxes were simultaneously monitored using static chamber-gas chromatography from three paired sites, including a cropland site (SC) and adjacent sites at two stages of afforestation, a shrubland (SD) and a woodland (AF). The results showed that annual soil CH4 uptake for SC, SD, and AF sites were 1.53 ± 0.20 kg C ha−1 yr−1, 2.90 ± 0.20 kg C ha−1 yr−1, and 5.68 ± 0.18 kg C ha−1 yr−1, respectively. Afforestation (i.e., SD and AF sites) significantly increased soil CH4 uptake compared with the adjacent cropland. Annual soil N2O fluxes for SC, SD, and AF sites were 2.38 ± 0.17 kg N ha−1 yr−1, 0.94 ± 0.14 kg N ha−1 yr−1, and 0.47 ± 0.01 kg N ha−1 yr−1, respectively. Afforestation significantly decreased soil N2O fluxes compared with the adjacent cropland. The effects of afforestation on soil CH4 and N2O fluxes in the present study were mainly attributed to changes in soil characteristics, such as temperature and moisture, as these were significantly correlated with soil CH4 and N2O fluxes across different experimental sites. The present study highlights that afforestation is an effective land use management practice to mitigate non-CO2 greenhouse gas emissions from subtropical karst landscapes in South China.},
author = {Chen, Ping and Zhou, Minghua and Wang, Shijie and Luo, Weijun and Peng, Tao and Zhu, Bo and Wang, Tao},
doi = {10.1016/j.scitotenv.2019.135974},
issn = {0048-9697},
journal = {Science of The Total Environment},
pages = {135974},
title = {{Effects of afforestation on soil CH4 and N2O fluxes in a subtropical karst landscape}},
volume = {705},
year = {2019}
}
@article{Chen2020,
abstract = {The Arctic is warming far faster than the global average, threatening the release of large amounts of carbon presently stored in frozen permafrost soils. Increasing Earth's albedo by the injection of sulfate aerosols into the stratosphere has been proposed as a way of offsetting some of the adverse effects of climate change. We examine this hypothesis in respect of permafrost carbon-climate feedbacks using the PInc-PanTher process model driven by seven earth system models running the Geoengineering Model Intercomparison Project (GeoMIP) G4 stratospheric aerosol injection scheme to reduce radiative forcing under the Representative Concentration Pathway (RCP) 4.5 scenario. Permafrost carbon released as CO2 is halved and as CH4 by 40{\%} under G4 compared with RCP4.5. Economic losses avoided solely by the roughly 14 Pg carbon kept in permafrost soils amount to about US{\$} 8.4 trillion by 2070 compared with RCP4.5, and indigenous habits and lifestyles would be better conserved.},
author = {Chen, Yating and Liu, Aobo and Moore, John C},
doi = {10.1038/s41467-020-16357-8},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {2430},
title = {{Mitigation of Arctic permafrost carbon loss through stratospheric aerosol geoengineering}},
volume = {11},
year = {2020}
}
@article{Chen2009,
abstract = {Despite their moderately sized surface area, continental marginal seas play a significant role in the biogeochemical cycles of carbon, as they receive huge amounts of upwelled and riverine inputs of carbon and nutrients, sustaining a disproportionate large biological activity compared to their relative surface area. A synthesis of worldwide measurements of the partial pressure Of CO(2) (pCO(2)) indicates that most open shelves in the temperate and high-latitude regions are under-saturated with respect to atmospheric CO(2) during all seasons, although the low-latitude shelves seem to be over-saturated. Most inner estuaries and near-shore coastal areas on the other hand are over-saturated with respect to atmospheric CO(2). The scaling of air-sea CO(2) fluxes based on pCO(2) measurements and carbon mass-balance calculations indicate that the continental shelves absorb atmospheric CO(2) ranging between 0.33 and 0.36 Pg C yr(-1) that corresponds to an additional sink of 27{\%} to similar to 30{\%} of the CO(2) uptake by the open oceans based on the most recent pCO(2) climatology [Takahashi, T., Sutherland, S.C., Wanninkhof, R., Sweeney, C., Feely, R.A., Chipman, D., Hales, B., Friederich, G., Chavez, F., Watson, A., Bakker, D., Schuster, U., Metzl, N., Inoue, H.Y., Ishii, M., Midorikawa, T., Sabine, C., Hoppema, M., Olafsson, J., Amarson, T., Tilbrook, B., Johannessen, T., Olsen, A., Bellerby, R., De Baar, H., Nojiri, Y., Wong. C.S., Delille, B., Bates, N., 2009. Climatological mean and decadal change in surface ocean pCO(2), and net sea-air CO(2) flux over the global oceans. Deep-Sea Research 11, this issue [doi: 10.1016/j.dsr2.2008.12.009].]. Inner estuaries, salt marshes and mangroves emit up to 0.50 Pg C yr(-1), although these estimates are prone to large uncertainty due to poorly constrained ecosystem surface area estimates. Nevertheless, the view of continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO(2) allows reconciling long-lived opposing views on carbon cycling in the coastal ocean. (C) 2009 Elsevier Ltd. All rights reserved.},
author = {Chen, Chen-Tung Arthur and Borges, Alberto V. V.},
doi = {10.1016/j.dsr2.2009.01.001},
issn = {09670645},
journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
month = {apr},
number = {8-10},
pages = {578--590},
publisher = {Pergamon},
title = {{Reconciling opposing views on carbon cycling in the coastal ocean: Continental shelves as sinks and near-shore ecosystems as sources of atmospheric CO2}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0967064509000162 https://www.sciencedirect.com/science/article/pii/S0967064509000162},
volume = {56},
year = {2009}
}
@article{Cheng2017a,
abstract = {Quantifying the responses of the coupled carbon and water cycles to current global warming and rising atmospheric CO2 concentration is crucial for predicting and adapting to climate changes. Here we show that terrestrial carbon uptake (i.e. gross primary production) increased significantly from 1982 to 2011 using a combination of ground-based and remotely sensed land and atmospheric observations. Importantly, we find that the terrestrial carbon uptake increase is not accompanied by a proportional increase in water use (i.e. evapotranspiration) but is largely (about 90{\%}) driven by increased carbon uptake per unit of water use, i.e. water use efficiency. The increased water use efficiency is positively related to rising CO2 concentration and increased canopy leaf area index, and negatively influenced by increased vapour pressure deficits. Our findings suggest that rising atmospheric CO2 concentration has caused a shift in terrestrial water economics of carbon uptake.},
author = {Cheng, Lei and Zhang, Lu and Wang, Ying-Ping and Canadell, Josep G. and Chiew, Francis H. S. and Beringer, Jason and Li, Longhui and Miralles, Diego G. and Piao, Shilong and Zhang, Yongqiang},
doi = {10.1038/s41467-017-00114-5},
isbn = {2041-1723},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {110},
title = {{Recent increases in terrestrial carbon uptake at little cost to the water cycle}},
url = {https://www.nature.com/articles/s41467-017-00114-5 http://www.nature.com/articles/s41467-017-00114-5},
volume = {8},
year = {2017}
}
@article{Chevallier2005a,
abstract = {Properly handling satellite data to constrain the inversion of CO2 sources and sinks at the Earth surface is a challenge motivated by the limitations of the current surface observation network. In this paper we present a Bayesian inference scheme to tackle this issue. It is based on the same theoretical principles as most inversions of the flask network but uses a variational formulation rather than a pure matrix-based one in order to cope with the large amount of satellite data. The minimization algorithm iteratively computes the optimum solution to the inference problem as well as an estimation of its error characteristics and some quantitative measures of the observation information content. A global climate model, guided by analyzed winds, provides information about the atmospheric transport to the inversion scheme. A surface flux climatology regularizes the inference problem. This new system has been applied to 1 year's worth of retrievals of vertically integrated CO2 concentrations from the Television Infrared Observation Satellite Operational Vertical Sounder (TOVS). Consistent with a recent study that identified regional biases in the TOVS retrievals, the inferred fluxes are not useful for biogeochemical analyses. In addition to the detrimental impact of these biases, we find a sensitivity of the results to the formulation of the prior uncertainty and to the accuracy of the transport model. Notwithstanding these difficulties, four-dimensional inversion schemes of the type presented here could form the basis of multisensor data assimilation systems for the estimation of the surface fluxes of key atmospheric compounds. Copyright 2005 by the American Geophysical Union.},
author = {Chevallier, Frederic and Fisher, M. and Peylin, P. and Serrar, S. and Bousquet, P. and Br{\'{e}}on, F.-M. and Ch{\'{e}}din, A. and Ciais, P.},
doi = {10.1029/2005JD006390},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Atmospheres},
number = {D24},
pages = {D24309},
title = {{Inferring CO2 sources and sinks from satellite observations: Method and application to TOVS data}},
url = {http://doi.wiley.com/10.1029/2005JD006390},
volume = {110},
year = {2005}
}
@article{Chierici2009,
author = {Chierici, M and Fransson, A},
doi = {10.5194/bg-6-2421-2009},
issn = {1726-4189},
journal = {Biogeosciences},
month = {nov},
number = {11},
pages = {2421--2431},
title = {{Calcium carbonate saturation in the surface water of the Arctic Ocean: undersaturation in freshwater influenced shelves}},
url = {https://www.biogeosciences.net/6/2421/2009/ http://www.biogeosciences.net/6/2421/2009/},
volume = {6},
year = {2009}
}
@article{Chou2013a,
abstract = {Abstract. Model studies suggested that human-induced increase in nutrient load may have stimulated primary production and thus enhanced the CO2 uptake capacity in the coastal ocean. In this study, we investigated the seasonal variations of the surface water's partial pressure of CO2 (pCO2sw) in the highly human-impacted Changjiang–East China Sea system between 2008 and 2011. The seasonality of pCO2sw has large spatial variations, with the largest extreme of 170 ± 75 $\mu$atm on the inner shelf near the Changjiang Estuary (from 271 ± 55 $\mu$atm in summer to 441 ± 51 $\mu$atm in autumn) and the weakest extreme of 53 ± 20 $\mu$atm on the outer shelf (from 328 ± 9 $\mu$atm in winter to 381 ± 18 $\mu$atm in summer). During the summer period, stronger stratification and biological production driven by the eutrophic Changjiang plume results in a very low dissolved inorganic carbon (DIC) in surface waters and a very high DIC in bottom waters of the inner shelf, with the latter returning high DIC to the surface water during the mixed period. Interestingly, a comparison with historical data shows that the average pCO2sw on the inner shelf near the Changjiang Estuary has decreased notably during summer, but has increased during autumn and winter from the 1990s to the 2000s. We suggest that this decadal change is associated with recently increased eutrophication. This would increase both the photosynthetic removal of DIC in surface waters and the respiratory release of DIC in bottom waters during summertime, thereby returning more DIC to the surface during the subsequent mixing seasons and/or episodic extreme weather events (e.g., typhoons). Our finding demonstrates that increasing anthropogenic nutrient delivery from a large river may enhance the sequestration capacity of CO2 in summer but may reduce it in autumn and winter. Consequently, the coastal ocean may not necessarily take up more atmospheric CO2 in response to increasing eutrophication, and the net effect largely depends on the relative timescale of air–sea gas exchange and offshore transport of the shelf water. Finally, the case we report for the Changjiang system may have general ramifications for other eutrophic coastal oceans.},
author = {Chou, W.-C. and Gong, G.-C. and Cai, W.-J. and Tseng, C.-M.},
doi = {10.5194/bg-10-3889-2013},
issn = {1726-4189},
journal = {Biogeosciences},
language = {English},
month = {jun},
number = {6},
pages = {3889--3899},
publisher = {Copernicus GmbH},
title = {{Seasonality of CO2 in coastal oceans altered by increasing anthropogenic nutrient delivery from large rivers: evidence from the Changjiang–East China Sea system}},
volume = {10},
year = {2013}
}
@article{ChowdhryBeeman2019,
abstract = {The last deglaciation, which occurred from 18 000 to 11 000 years ago, is the most recent large natural climatic variation of global extent. With accurately dated paleoclimate records, we can investigate the timings of related variables in the climate system during this major transition. Here, we use an accurate relative chronology to compare temperature proxy data and global atmospheric CO 2 as recorded in Antarctic ice cores. In addition to five regional records, we compare a $\delta$ 18 O stack, representing Antarctic climate variations with the high-resolution robustly dated WAIS Divide CO 2 record (West Antarctic Ice Sheet). We assess the CO 2 and Antarctic temperature phase relationship using a stochastic method to accurately identify the probable timings of changes in their trends. Four coherent changes are identified for the two series, and synchrony between CO 2 and temperature is within the 95{\%} uncertainty range for all of the changes except the end of glacial termination 1 (T1). During the onset of the last deglaciation at 18 ka and the deglaciation end at 11.5 ka, Antarctic temperature most likely led CO 2 by several centuries (by 570 years, within a range of 127 to 751 years, 68{\%} probability, at the T1 onset; and by 532 years, within a range of 337 to 629 years, 68{\%} probability, at the deglaciation end). At 14.4 ka, the onset of the Antarctic Cold Reversal (ACR) period, our results do not show a clear lead or lag (Antarctic temperature leads by 50 years, within a range of -137 to 376 years, 68{\%} probability). The same is true at the end of the ACR (CO 2 leads by 65 years, within a range of 211 to 117 years, 68{\%} probability). However, the timings of changes in trends for the individual proxy records show variations from the stack, indicating regional differences in the pattern of temperature change, particularly in the WAIS Divide record at the onset of the deglaciation; the Dome Fuji record at the deglaciation end; and the EDML record after 16 ka (EPICA Dronning Maud Land, where EPICA is the European Project for Ice Coring in Antarctica). In addition, two changes - one at 16 ka in the CO 2 record and one after the ACR onset in three of the isotopic temperature records - do not have high-probability counterparts in the other record. The likely-variable phasing we identify testify to the complex nature of the mechanisms driving the carbon cycle and Antarctic temperature during the deglaciation.},
author = {{Chowdhry Beeman}, Jai and Gest, L{\'{e}}a and Parrenin, Fr{\'{e}}d{\'{e}}ric and Raynaud, Dominique and Fudge, Tyler J. and Buizert, Christo and Brook, Edward J.},
doi = {10.5194/cp-15-913-2019},
issn = {18149332},
journal = {Climate of the Past},
number = {3},
pages = {913--926},
title = {{Antarctic temperature and CO2: Near-synchrony yet variable phasing during the last deglaciation}},
volume = {15},
year = {2019}
}
@article{Chu2016,
abstract = {Abstract In order to understand the ocean's role as a sink for anthropogenic carbon dioxide (CO2), it is important to quantify changes in the amount of anthropogenic CO2 stored in the ocean interior over time. From August to September 2012, an ocean acidification cruise was conducted along a portion of the P17N transect (50°N 150°W to 33.5°N 135°W) in the Northeast Pacific. These measurements are compared with data from the previous occupation of this transect in 2001 to estimate the change in the anthropogenic CO2 inventory in the Northeast Pacific using an extended multiple linear regression (eMLR) approach. Maximum increases in the surface waters were 11 µmol kg?1 over 11 years near 50°N. Here, the penetration depth of anthropogenic CO2 only reached ?300 m depth, whereas at 33.5°N, penetration depth reached ?600 m. The average increase of the depth-integrated anthropogenic carbon inventory was 0.41?±?0.12 mol m?2 yr?1 across the transect. Lower values down to 0.20 mol m?2 yr?1 were observed in the northern part of the transect near 50°N and increased up to 0.55 mol m?2 yr?1 toward 33.5°N. This increase in anthropogenic carbon in the upper ocean resulted in an average pH decrease of 0.002?±?0.0003 pH units yr?1 and a 1.8?±?0.4 m yr?1 shoaling rate of the aragonite saturation horizon. An average increase in apparent oxygen utilization of 13.4?±?15.5 µmol kg?1 centered on isopycnal surface 26.6 kg m?3 from 2001 to 2012 was also observed.},
annote = {doi: 10.1002/2016JC011775},
author = {Chu, Sophie N and Wang, Zhaohui Aleck and Doney, Scott C and Lawson, Gareth L and Hoering, Katherine A},
doi = {10.1002/2016JC011775},
issn = {21699275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Northeast Pacific,anthropogenic carbon,carbon dioxide,carbonate chemistry,dissolved inorganic carbon,ocean acidification},
month = {jul},
number = {7},
pages = {4618--4632},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Changes in anthropogenic carbon storage in the Northeast Pacific in the last decade}},
url = {https://doi.org/10.1002/2016JC011775 http://doi.wiley.com/10.1002/2016JC011775},
volume = {121},
year = {2016}
}
@article{Churkina2020,
abstract = {The anticipated growth and urbanization of the global population over the next several decades will create a vast demand for the construction of new housing, commercial buildings and accompanying infrastructure. The production of cement, steel and other building materials associated with this wave of construction will become a major source of greenhouse gas emissions. Might it be possible to transform this potential threat to the global climate system into a powerful means to mitigate climate change? To answer this provocative question, we explore the potential of mid-rise urban buildings designed with engineered timber to provide long-term storage of carbon and to avoid the carbon-intensive production of mineral-based construction materials.},
author = {Churkina, Galina and Organschi, Alan and Reyer, Christopher P O and Ruff, Andrew and Vinke, Kira and Liu, Zhu and Reck, Barbara K and Graedel, T E and Schellnhuber, Hans Joachim},
doi = {10.1038/s41893-019-0462-4},
issn = {2398-9629},
journal = {Nature Sustainability},
number = {4},
pages = {269--276},
title = {{Buildings as a global carbon sink}},
url = {https://doi.org/10.1038/s41893-019-0462-4},
volume = {3},
year = {2020}
}
@article{Chuvilin2018,
abstract = {Gases releasing from shallow permafrost above 150 m may contain methane produced by the dissociation of pore metastable gas hydrates, which can exist in permafrost due to self-preservation. In this study, special experiments were conducted to study the self-preservation kinetics. For this, sandy samples from gas-bearing permafrost horizons in West Siberia were first saturated with methane hydrate and frozen and then exposed to gas pressure drop below the triple-phase equilibrium in the “gas–gas hydrate–ice” system. The experimental results showed that methane hydrate could survive for a long time in frozen soils at temperatures of −5 to −7 °C at below-equilibrium pressures, thus evidencing the self-preservation effect. The self-preservation of gas hydrates in permafrost depends on its temperature, salinity, ice content, and gas pressure. Prolonged preservation of metastable relict hydrates is possible in ice-rich sandy permafrost at −4 to −5 °C or colder, with a salinity of {\textless}0.1{\%} at depths below 20–30 m.},
author = {Chuvilin, Evgeny and Bukhanov, Boris and Davletshina, Dinara and Grebenkin, Sergey and Istomin, Vladimir},
doi = {10.3390/geosciences8120431},
issn = {2076-3263},
journal = {Geosciences},
month = {nov},
number = {12},
pages = {431},
title = {{Dissociation and self-preservation of gas hydrates in permafrost}},
url = {http://www.mdpi.com/2076-3263/8/12/431},
volume = {8},
year = {2018}
}
@incollection{Ciais2013,
address = {Cambridge, United Kingdom and New York, NY, USA},
author = {Ciais, P. and Sabine, C. and Bala, G. and Bopp, L. and Brovkin, V. and Canadell, J. and Chhabra, A. and DeFries, R. and Galloway, J. and Heimann, M. and Jones, C. and Qu{\'{e}}r{\'{e}}, C. Le and Myneni, R.B. and Piao, S. and Thornton, P.},
booktitle = {Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change},
doi = {10.1017/CBO9781107415324.015},
editor = {Stocker, T.F. and Qin, D. and Plattner, G.-K. and Tignor, M. and Allen, S.K. and Boschung, J. and Nauels, A. and Xia, Y. and Bex, V. and Midgley, P.M.},
isbn = {9781107661820},
pages = {465--570},
publisher = {Cambridge University Press},
title = {{Carbon and Other Biogeochemical Cycles}},
url = {http://www.ipcc.ch/report/ar5/wg1},
year = {2013}
}
@article{Ciais2012a,
abstract = {During each of the late Pleistocene glacial–interglacial transitions, atmospheric carbon dioxide concentrations rose by almost 100 ppm. The sources of this carbon are unclear, and efforts to identify them are hampered by uncertainties in the magnitude of carbon reservoirs and fluxes under glacial conditions. Here we use oxygen isotope measurements from air trapped in ice cores and ocean carbon-cycle modelling to estimate terrestrial and oceanic gross primary productivity during the Last Glacial Maximum. We find that the rate of gross terrestrial primary production during the Last Glacial Maximum was about 40±10 Pg C yr−1, half that of the pre-industrial Holocene. Despite the low levels of photosynthesis, we estimate that the late glacial terrestrial biosphere contained only 330 Pg less carbon than pre-industrial levels. We infer that the area covered by carbon-rich but unproductive biomes such as tundra and cold steppes was significantly larger during the Last Glacial Maximum, consistent with palaeoecological data. Our data also indicate the presence of an inert carbon pool of 2,300 Pg C, about 700 Pg larger than the inert carbon locked in permafrost today. We suggest that the disappearance of this carbon pool at the end of the Last Glacial Maximum may have contributed to the deglacial rise in atmospheric carbon dioxide concentrations.},
author = {Ciais, P. and Tagliabue, A. and Cuntz, M. and Bopp, L. and Scholze, M. and Hoffmann, G. and Lourantou, A. and Harrison, S. P. and Prentice, I. C. and Kelley, D. I. and Koven, C. and Piao, S. L.},
doi = {10.1038/ngeo1324},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jan},
number = {1},
pages = {74--79},
title = {{Large inert carbon pool in the terrestrial biosphere during the Last Glacial Maximum}},
url = {http://www.nature.com/articles/ngeo1324},
volume = {5},
year = {2012}
}
@article{Ciais2019b,
abstract = {The global land and ocean carbon sinks have increased proportionally with increasing carbon dioxide emissions during the past decades 1 . It is thought that Northern Hemisphere lands make a dominant contribution to the global land carbon sink 2–7 ; however, the long-term trend of the northern land sink remains uncertain. Here, using measurements of the interhemispheric gradient of atmospheric carbon dioxide from 1958 to 2016, we show that the northern land sink remained stable between the 1960s and the late 1980s, then increased by 0.5 ± 0.4 petagrams of carbon per year during the 1990s and by 0.6 ± 0.5 petagrams of carbon per year during the 2000s. The increase of the northern land sink in the 1990s accounts for 65{\%} of the increase in the global land carbon flux during that period. The subsequent increase in the 2000s is larger than the increase in the global land carbon flux, suggesting a coincident decrease of carbon uptake in the Southern Hemisphere. Comparison of our findings with the simulations of an ensemble of terrestrial carbon models 5,8 over the same period suggests that the decadal change in the northern land sink between the 1960s and the 1990s can be explained by a combination of increasing concentrations of atmospheric carbon dioxide, climate variability and changes in land cover. However, the increase during the 2000s is underestimated by all models, which suggests the need for improved consideration of changes in drivers such as nitrogen deposition, diffuse light and land-use change. Overall, our findings underscore the importance of Northern Hemispheric land as a carbon sink.},
author = {Ciais, P. and Tan, J. and Wang, X. and Roedenbeck, C. and Chevallier, F. and Piao, S.-L. and Moriarty, R. and Broquet, G. and {Le Qu{\'{e}}r{\'{e}}}, C. and Canadell, Josep G. and Peng, S. and Poulter, B. and Liu, Z. and Tans, P.},
doi = {10.1038/s41586-019-1078-6},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7751},
pages = {221--225},
title = {{Five decades of northern land carbon uptake revealed by the interhemispheric CO2 gradient}},
url = {http://www.nature.com/articles/s41586-019-1078-6},
volume = {568},
year = {2019}
}
@article{Ciais2005,
abstract = {Future climate warming is expected to enhance plant growth in temperate ecosystems and to increase carbon sequestration. But although severe regional heatwaves may become more frequent in a changing climate, their impact on terrestrial carbon cycling is unclear. Here we report measurements of ecosystem carbon dioxide fluxes, remotely sensed radiation absorbed by plants, and country-level crop yields taken during the European heatwave in 2003. We use a terrestrial biosphere simulation model to assess continental-scale changes in primary productivity during 2003, and their consequences for the net carbon balance. We estimate a 30 per cent reduction in gross primary productivity over Europe, which resulted in a strong anomalous net source of carbon dioxide (0.5 Pg C yr-1) to the atmosphere and reversed the effect of four years of net ecosystem carbon sequestration. Our results suggest that productivity reduction in eastern and western Europe can be explained by rainfall deficit and extreme summer heat, respectively. We also find that ecosystem respiration decreased together with gross primary productivity, rather than accelerating with the temperature rise. Model results, corroborated by historical records of crop yields, suggest that such a reduction in Europe's primary productivity is unprecedented during the last century. An increase in future drought events could turn temperate ecosystems into carbon sources, contributing to positive carbon-climate feedbacks already anticipated in the tropics and at high latitudes. {\textcopyright} 2005 Nature Publishing Group.},
author = {Ciais, Ph and Reichstein, M. and Viovy, N. and Granier, A. and Og{\'{e}}e, J. and Allard, V. and Aubinet, M. and Buchmann, N. and Bernhofer, Chr and Carrara, A. and Chevallier, F. and {De Noblet}, N. and Friend, A. D. and Friedlingstein, P. and Gr{\"{u}}nwald, T. and Heinesch, B. and Keronen, P. and Knohl, A. and Krinner, G. and Loustau, D. and Manca, G. and Matteucci, G. and Miglietta, F. and Ourcival, J. M. and Papale, D. and Pilegaard, K. and Rambal, S. and Seufert, G. and Soussana, J. F. and Sanz, M. J. and Schulze, E. D. and Vesala, T. and Valentini, R.},
doi = {10.1038/nature03972},
issn = {14764687},
journal = {Nature},
number = {7058},
pages = {529--533},
pmid = {16177786},
title = {{Europe-wide reduction in primary productivity caused by the heat and drought in 2003}},
volume = {437},
year = {2005}
}
@article{Claret2018a,
abstract = {Global observations show that the ocean lost approximately 2{\%} of its oxygen inventory over the past five decades1–3, with important implications for marine ecosystems4,5. The rate of change varies regionally, with northwest Atlantic coastal waters showing a long-term drop6,7 that vastly outpaces the global and North Atlantic basin mean deoxygenation rates5,8. However, past work has been unable to differentiate the role of large-scale climate forcing from that of local processes. Here, we use hydrographic evidence to show that a Labrador Current retreat is playing a key role in the deoxygenation on the northwest Atlantic shelf. A high-resolution global coupled climate–biogeochemistry model9 reproduces the observed decline of saturation oxygen concentrations in the region, driven by a retreat of the equatorward-flowing Labrador Current and an associated shift towards more oxygen-poor subtropical waters on the shelf. The dynamical changes underlying the shift in shelf water properties are correlated with a slowdown in the simulated Atlantic Meridional Overturning Circulation (AMOC)10. Our results provide strong evidence that a major, centennial-scale change of the Labrador Current is underway, and highlight the potential for ocean dynamics to impact coastal deoxygenation over the coming century.},
author = {Claret, Mariona and Galbraith, Eric D and Palter, Jaime B and Bianchi, Daniele and Fennel, Katja and Gilbert, Denis and Dunne, John P},
doi = {10.1038/s41558-018-0263-1},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {oct},
number = {10},
pages = {868--872},
title = {{Rapid coastal deoxygenation due to ocean circulation shift in the northwest Atlantic}},
url = {https://doi.org/10.1038/s41558-018-0263-1 http://www.nature.com/articles/s41558-018-0263-1},
volume = {8},
year = {2018}
}
@incollection{Clarke2014,
address = {Cambridge, United Kingdom and New York, NY, USA},
author = {Clarke, L and Jiang, K and Akimoto, K and Babiker, M and Blanford, G and Fisher-Vanden, K and Hourcade, J.-C. and Krey, V and Kriegler, E and L{\"{o}}schel, A and McCollum, D and Paltsev, S and Rose, S and Shukla, P R and Tavoni, M and van der Zwaan, B C C and van Vuuren, D P},
booktitle = {Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change},
doi = {10.1017/CBO9781107415416.012},
editor = {Edenhofer, O and Pichs-Madruga, R and Sokona, Y and Farahani, E and Kadner, S and Seyboth, K and Adler, A and Baum, I and Brunner, S and Eickemeier, P and Kriemann, B and Savolainen, J and Schl{\"{o}}mer, S and von Stechow, C and Zwickel, T and Minx, J C},
isbn = {9781107058217},
pages = {413--510},
publisher = {Cambridge University Press},
title = {{Assessing transformation pathways}},
url = {https://www.ipcc.ch/report/ar5/wg3},
year = {2014}
}
@article{Clarkson2021,
abstract = {The Paleocene Eocene Thermal Maximum (PETM) represents a major carbon cycle and climate perturbation that was associated with ocean de-oxygenation, in a qualitatively similar manner to the more extensive Mesozoic Oceanic Anoxic Events. Although indicators of ocean de-oxygenation are common for the PETM, and linked to biotic turnover, the global extent and temporal progression of de-oxygenation is poorly constrained. Here we present carbonate associated uranium isotope data for the PETM. A lack of resolvable perturbation to the U-cycle during the event suggests a limited expansion of seafloor anoxia on a global scale. We use this result, in conjunction with a biogeochemical model, to set an upper limit on the extent of global seafloor de-oxygenation. The model suggests that the new U isotope data, whilst also being consistent with plausible carbon emission scenarios and observations of carbon cycle recovery, permit a maximum {\~{}}10-fold expansion of anoxia, covering {\textless}2{\%} of seafloor area.},
author = {Clarkson, Matthew O and Lenton, Timothy M and Andersen, Morten B and Bagard, Marie-laure and Dickson, Alexander J and Vance, Derek},
doi = {10.1038/s41467-020-20486-5},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {399},
title = {{Upper limits on the extent of seafloor anoxia during the PETM from uranium isotopes}},
url = {http://dx.doi.org/10.1038/s41467-020-20486-5 http://www.nature.com/articles/s41467-020-20486-5},
volume = {12},
year = {2021}
}
@article{agronomy3020275,
abstract = {Interest in biochar stems from its potential agronomic benefits and carbon sequestration ability. Biochar application alters soil nitrogen (N) dynamics. This review establishes emerging trends and gaps in biochar-N research. Biochar adsorption of NO3−, up to 0.6 mg g−1 biochar, occurs at pyrolysis temperatures {\textgreater}600 °C with amounts adsorbed dependent on feedstock and NO3− concentration. Biochar NH4+ adsorption depends on feedstock, but no pyrolysis temperature trend is apparent. Long-term practical effectiveness of inorganic-N adsorption, as a NO3− leaching mitigation option, requires further study. Biochar adsorption of ammonia (NH3) decreases NH3 and NO3− losses during composting and after manure applications, and offers a mechanism for developing slow release fertilisers. Reductions in NH3 loss vary with N source and biochar characteristics. Manure derived biochars have a role as N fertilizers. Increasing pyrolysis temperatures, during biochar manufacture from manures and biosolids, results in biochars with decreasing hydrolysable organic N and increasing aromatic and heterocyclic structures. The short- and long-term implications of biochar on N immobilisation and mineralization are specific to individual soil-biochar combinations and further systematic studies are required to predict agronomic and N cycling responses. Most nitrous oxide (N2O) studies measuring nitrous oxide (N2O) were short-term in nature and found emission reductions, but long-term studies are lacking, as is mechanistic understanding of reductions. Stable N isotopes have a role in elucidating biochar-N-soil dynamics. There remains a dearth of information regarding effects of biochar and soil biota on N cycling. Biochar has potential within agroecosystems to be an N input, and a mitigation agent for environmentally detrimental N losses. Future research needs to systematically understand biochar-N interactions over the long term.},
author = {Clough, Tim and Condron, Leo and Kammann, Claudia and M{\"{u}}ller, Christoph},
doi = {10.3390/agronomy3020275},
issn = {2073-4395},
journal = {Agronomy},
month = {apr},
number = {2},
pages = {275--293},
title = {{A review of biochar and soil nitrogen dynamics}},
url = {http://www.mdpi.com/2073-4395/3/2/275},
volume = {3},
year = {2013}
}
@article{CobbE5187,
abstract = {A dataset from one of the last protected tropical peat swamps in Southeast Asia reveals how fluctuations in rainfall on yearly and shorter timescales affect the growth and subsidence of tropical peatlands over thousands of years. The pattern of rainfall and the permeability of the peat together determine a particular curvature of the peat surface that defines the amount of naturally sequestered carbon stored in the peatland over time. This principle can be used to calculate the long-term carbon dioxide emissions driven by changes in climate and tropical peatland drainage. The results suggest that greater seasonality projected by climate models could lead to carbon dioxide emissions, instead of sequestration, from otherwise undisturbed peat swamps.Tropical peatlands now emit hundreds of megatons of carbon dioxide per year because of human disruption of the feedbacks that link peat accumulation and groundwater hydrology. However, no quantitative theory has existed for how patterns of carbon storage and release accompanying growth and subsidence of tropical peatlands are affected by climate and disturbance. Using comprehensive data from a pristine peatland in Brunei Darussalam, we show how rainfall and groundwater flow determine a shape parameter (the Laplacian of the peat surface elevation) that specifies, under a given rainfall regime, the ultimate, stable morphology, and hence carbon storage, of a tropical peatland within a network of rivers or canals. We find that peatlands reach their ultimate shape first at the edges of peat domes where they are bounded by rivers, so that the rate of carbon uptake accompanying their growth is proportional to the area of the still-growing dome interior. We use this model to study how tropical peatland carbon storage and fluxes are controlled by changes in climate, sea level, and drainage networks. We find that fluctuations in net precipitation on timescales from hours to years can reduce long-term peat accumulation. Our mathematical and numerical models can be used to predict long-term effects of changes in temporal rainfall patterns and drainage networks on tropical peatland geomorphology and carbon storage.},
author = {Cobb, Alexander R and Hoyt, Alison M and Gandois, Laure and Eri, Jangarun and Dommain, Ren{\'{e}} and {Abu Salim}, Kamariah and Kai, Fuu Ming and {Haji Su$\backslash$textquoterightut}, Nur Salihah and Harvey, Charles F},
doi = {10.1073/pnas.1701090114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {26},
pages = {E5187--E5196},
publisher = {National Academy of Sciences},
title = {{How temporal patterns in rainfall determine the geomorphology and carbon fluxes of tropical peatlands}},
url = {https://www.pnas.org/content/114/26/E5187},
volume = {114},
year = {2017}
}
@article{Cocquempot2019,
abstract = {To understand and predict the physical, chemical, and biological processes at play in coastal and nearshore marine areas requires an integrated, interdisciplinary approach. The case study of the French structuration of coastal ocean and nearshore observing systems provides an original overview on a federative research infrastructure named ILICO. It is a notable example of national structuration and pan-institution efforts to investigate the forefront of knowledge on the processes at work within the critical coastal zone. ILICO comprises, in a pluridisciplinary approach, eight distributed network-systems of observation and data analysis that are accredited and financially supported by French research institutions and the French Ministry for Higher Education, Research, and Innovation. ILICO observation points are implemented along metropolitan and overseas French coasts, where coastline dynamics, sea level evolution, physical and biogeochemical water properties, coastal water dynamics, phytoplankton composition, and health of coral reefs are monitored in order to address a wide range of scientific questions. To give an overview of the diversity and potential of the observations carried out, this paper offers a detailed presentation of three constituting networks: Service Observation en Milieu LITtoral (SOMLIT), with homogeneous sampling strategies, DYNALIT, with heterogeneous sampling strategies adapted to different environments, and Mediterranean Ocean Observing System for the Environment (MOOSE), an integrated, pluri-disciplinary coastal/offshore regional observatory in the north-western Mediterranean Sea. ILICO was conceived using a European framework. It addresses the great challenges of the next decade in terms of sustainability, cost-efficiency, interoperability, and innovation. This paper emphasizes the added-value of federating these systems, and highlights some recommendations for the future.},
author = {Cocquempot, Lucie and Delacourt, Christophe and Paillet, J{\'{e}}r{\^{o}}me and Riou, Philippe and Aucan, J{\'{e}}r{\^{o}}me and Castelle, Bruno and Charria, Guillaume and Claudet, Joachim and Conan, Pascal and Coppola, Laurent and Hocd{\'{e}}, R{\'{e}}gis and Planes, Serge and Raimbault, Patrick and Savoye, Nicolas and Testut, Laurent and Vuillemin, Renaud},
doi = {10.3389/fmars.2019.00324},
isbn = {2296-7745},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {jun},
pages = {324},
title = {{Coastal Ocean and Nearshore Observation: A French Case Study}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00324 https://www.frontiersin.org/article/10.3389/fmars.2019.00324/full},
volume = {6},
year = {2019}
}
@article{Codispoti2010,
author = {Codispoti, L. A.},
doi = {10.1126/science.1184945},
issn = {0036-8075},
journal = {Science},
month = {mar},
number = {5971},
pages = {1339--1340},
title = {{Interesting Times for Marine N2O}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1184945},
volume = {327},
year = {2010}
}
@article{bg-4-233-2007,
author = {Codispoti, L A},
doi = {10.5194/bg-4-233-2007},
issn = {1726-4189},
journal = {Biogeosciences},
month = {may},
number = {2},
pages = {233--253},
title = {{An oceanic fixed nitrogen sink exceeding 400 Tg N a-1 vs the concept of homeostasis in the fixed-nitrogen inventory}},
url = {https://www.biogeosciences.net/4/233/2007/ http://www.biogeosciences.net/4/233/2007/},
volume = {4},
year = {2007}
}
@article{Collier2018,
abstract = {The increasing complexity of Earth system models has inspired efforts to quantitatively assess model fidelity through rigorous comparison with best available measurements and observational data products. Earth system models exhibit a high degree of spread in predictions of land biogeochemistry, biogeophysics, and hydrology, which are sensitive to forcing from other model components. Based on insights from prior land model evaluation studies and community workshops, the authors developed an open source model benchmarking software package that generates graphical diagnostics and scores model performance in support of the International Land Model Benchmarking (ILAMB) project. Employing a suite of in situ, remote sensing, and reanalysis data sets, the ILAMB package performs comprehensive model assessment across a wide range of land variables and generates a hierarchical set of web pages containing statistical analyses and figures designed to provide the user insights into strengths and weaknesses of multiple models or model versions. Described here is the benchmarking philosophy and mathematical methodology embodied in the most recent implementation of the ILAMB package. Comparison methods unique to a few specific data sets are presented, and guidelines for configuring an ILAMB analysis and interpreting resulting model performance scores are discussed. ILAMB is being adopted by modeling teams and centers during model development and for model intercomparison projects, and community engagement is sought for extending evaluation metrics and adding new observational data sets to the benchmarking framework.},
author = {Collier, Nathan and Hoffman, Forrest M. and Lawrence, David M. and Keppel‐Aleks, Gretchen and Koven, Charles D. and Riley, William J. and Mu, Mingquan and Randerson, James T.},
doi = {10.1029/2018MS001354},
issn = {1942-2466},
journal = {Journal of Advances in Modeling Earth Systems},
keywords = {Earth system model,benchmarking,model evaluation},
month = {nov},
number = {11},
pages = {2731--2754},
title = {{The International Land Model Benchmarking (ILAMB) System: Design, Theory, and Implementation}},
url = {https://doi.org/10.1029/2018MS001354 https://onlinelibrary.wiley.com/doi/abs/10.1029/2018MS001354},
volume = {10},
year = {2018}
}
@article{acp-13-2471-2013,
abstract = {Abstract. We examine the climate effects of the emissions of near-term climate forcers (NTCFs) from 4 continental regions (East Asia, Europe, North America and South Asia) using results from the Task Force on Hemispheric Transport of Air Pollution Source-Receptor global chemical transport model simulations. We address 3 aerosol species (sulphate, particulate organic matter and black carbon) and 4 ozone precursors (methane, reactive nitrogen oxides (NOx), volatile organic compounds and carbon monoxide). We calculate the global climate metrics: global warming potentials (GWPs) and global temperature change potentials (GTPs). For the aerosols these metrics are simply time-dependent scalings of the equilibrium radiative forcings. The GTPs decrease more rapidly with time than the GWPs. The aerosol forcings and hence climate metrics have only a modest dependence on emission region. The metrics for ozone precursors include the effects on the methane lifetime. The impacts via methane are particularly important for the 20 yr GTPs. Emissions of NOx and VOCs from South Asia have GWPs and GTPs of higher magnitude than from the other Northern Hemisphere regions. The analysis is further extended by examining the temperature-change impacts in 4 latitude bands, and calculating absolute regional temperature-change potentials (ARTPs). The latitudinal pattern of the temperature response does not directly follow the pattern of the diagnosed radiative forcing. We find that temperatures in the Arctic latitudes appear to be particularly sensitive to BC emissions from South Asia. The northern mid-latitude temperature response to northern mid-latitude emissions is approximately twice as large as the global average response for aerosol emission, and about 20–30{\%} larger than the global average for methane, VOC and CO emissions.},
author = {Collins, W J and Fry, M M and Yu, H and Fuglestvedt, J S and Shindell, D T and West, J J},
doi = {10.5194/acp-13-2471-2013},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {mar},
number = {5},
pages = {2471--2485},
title = {{Global and regional temperature-change potentials for near-term climate forcers}},
url = {https://www.atmos-chem-phys.net/13/2471/2013/},
volume = {13},
year = {2013}
}
@article{Collins2018,
abstract = {To understand the importance of methane on the levels of carbon emission reductions required to achieve temperature goals, a processed-based approach is necessary rather than reliance on the transient climate response to emissions. We show that plausible levels of methane (CH 4 ) mitigation can make a substantial difference to the feasibility of achieving the Paris climate targets through increasing the allowable carbon emissions. This benefit is enhanced by the indirect effects of CH 4 on ozone (O 3 ). Here the differing effects of CH 4 and CO 2 on land carbon storage, including the effects of surface O 3 , lead to an additional increase in the allowable carbon emissions with CH 4 mitigation. We find a simple robust relationship between the change in the 2100 CH 4 concentration and the extra allowable cumulative carbon emissions between now and 2100 (0.27 ± 0.05 GtC per ppb CH 4 ). This relationship is independent of modelled climate sensitivity and precise temperature target, although later mitigation of CH 4 reduces its value and thus methane reduction effectiveness. Up to 12{\%} of this increase in allowable emissions is due to the effect of surface ozone. We conclude early mitigation of CH 4 emissions would significantly increase the feasibility of stabilising global warming below 1.5 °C, alongside having co-benefits for human and ecosystem health.},
author = {Collins, William J. and Webber, Christopher P. and Cox, Peter M. and Huntingford, Chris and Lowe, Jason and Sitch, Stephen and Chadburn, Sarah E. and Comyn-Platt, Edward and Harper, Anna B. and Hayman, Garry and Powell, Tom},
doi = {10.1088/1748-9326/aab89c},
issn = {1748-9326},
journal = {Environmental Research Letters},
keywords = {carbon budgets,climate targets,methane mitigation,non-CO2 greenhouse gases},
month = {apr},
number = {5},
pages = {054003},
title = {{Increased importance of methane reduction for a 1.5 degree target}},
url = {http://stacks.iop.org/1748-9326/13/i=5/a=054003?key=crossref.70d07fb114d80fc70bd1b8927f03ac6b},
volume = {13},
year = {2018}
}
@incollection{Collins2013,
address = {Cambridge, United Kingdom and New York, NY, USA},
author = {Collins, Matthew and Knutti, Reto and Arblaster, Julie and Dufresne, J.-L. and Fichefet, Thierry and Friedlingstein, Pierre and Gao, Xuejie and Gutowski, William and Johns, Tim and Krinner, Gerhard and Shongwe, Mxolisi and Tebaldi, Claudia and Weaver, Andrew J. and Wehner, Michael},
booktitle = {Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change},
chapter = {12},
doi = {10.1017/CBO9781107415324.024},
editor = {Stocker, T F and Qin, D and Plattner, G.-K. and Tignor, M and Allen, S K and Boschung, J and Nauels, A and Xia, Y and Bex, V and Midgley, P M},
isbn = {9781107661820},
pages = {1029--1136},
publisher = {Cambridge University Press},
title = {{Long-term Climate Change: Projections, Commitments and Irreversibility}},
url = {https://www.ipcc.ch/report/ar5/wg1},
year = {2013}
}
@article{commane2017carbon,
author = {Commane, R{\'{o}}is$\backslash$'$\backslash$in and Lindaas, Jakob and Benmergui, Joshua and Luus, Kristina A and Chang, Rachel Y-W and Daube, Bruce C and Euskirchen, Eug{\'{e}}nie S and Henderson, John M and Karion, Anna and Miller, John B and Others},
doi = {10.1073/pnas.1618567114},
journal = {Proceedings of the National Academy of Sciences},
number = {21},
pages = {5361--5366},
publisher = {National Acad Sciences},
title = {{Carbon dioxide sources from Alaska driven by increasing early winter respiration from Arctic tundra}},
volume = {114},
year = {2017}
}
@article{Comyn-Platt2018,
abstract = {Global methane emissions from natural wetlands and carbon release from permafrost thaw have a positive feedback on climate, yet are not represented in most state-of-the-art climate models. Furthermore, a fraction of the thawed permafrost carbon is released as methane, enhancing the combined feedback strength. We present simulations with an inverted intermediate complexity climate model, which follows prescribed global warming pathways to stabilization at 1.5 or 2.0 °C above pre-industrial levels by the year 2100, and which incorporates a state-of-the-art global land surface model with updated descriptions of wetland and permafrost carbon release. We demonstrate that the climate feedbacks from those two processes are substantial. Specifically, permissible anthropogenic fossil fuel CO2 emission budgets are reduced by 17–23{\%} (47–56 GtC) for stabilization at 1.5 °C, and 9–13{\%} (52–57 GtC) for 2.0 °C stabilization. In our simulations these feedback processes respond more quickly at temperatures below 1.5 °C, and the differences between the 1.5 and 2 °C targets are disproportionately small. This key finding holds for transient emission pathways to 2100 and does not account for longer-term implications of these feedback processes. We conclude that natural feedback processes from wetlands and permafrost must be considered in assessments of transient emission pathways to limit global warming.},
author = {Comyn-Platt, Edward and Hayman, Garry and Huntingford, Chris and Chadburn, Sarah E. and Burke, Eleanor J. and Harper, Anna B. and Collins, William J. and Webber, Christopher P. and Powell, Tom and Cox, Peter M. and Gedney, Nicola and Sitch, Stephen},
doi = {10.1038/s41561-018-0174-9},
isbn = {1752-0894 1752-0908},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {aug},
number = {8},
pages = {568--573},
title = {{Carbon budgets for 1.5 and 2°C targets lowered by natural wetland and permafrost feedbacks}},
url = {http://www.nature.com/articles/s41561-018-0174-9},
volume = {11},
year = {2018}
}
@article{Conrad2015,
abstract = {AbstractSeasonal and interannual variability in the Southern Ocean carbonate system is investigated using output from a historically forced (1948–2007) ocean general circulation model with embedded biogeochemistry. Atmospheric CO2 is fixed at preindustrial levels to investigate carbonate system variability in the absence of an anthropogenic CO2 perturbation. It is found that nearly a quarter of interannual variability in Southern Ocean Pacific sector surface carbonate ion concentration can be explained by variability in ENSO, with Pacific sector surface decreasing by 0.43 mmol m−3 per standard deviation decrease in the ENSO-3.4 index. ENSO-related variability in vertical advection of dissolved inorganic carbon (DIC) drives this relationship between ENSO and surface . It is also found that positive phases of the southern annular mode (SAM) are associated with decreased Southern Ocean surface , an association driven by SAM-related variability in vertical advection of DIC. Despite the influence of the SAM on...},
author = {Conrad, Christopher J. and Lovenduski, Nicole S.},
doi = {10.1175/JCLI-D-14-00481.1},
issn = {0894-8755},
journal = {Journal of Climate},
keywords = {Annular mode,Climate models,Climate variability,ENSO,Hindcasts,Southern Ocean},
month = {jul},
number = {13},
pages = {5335--5350},
title = {{Climate-driven variability in the Southern Ocean carbonate system}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-14-00481.1},
volume = {28},
year = {2015}
}
@article{Conway1994a,
address = {Washington, D.C. :},
author = {Conway, Thomas J. and Tans, Pieter P. and Waterman, Lee S. and Thoning, Kirk W. and Kitzis, Duane R. and Masarie, Kenneth A. and Zhang, Ni},
doi = {10.1029/94JD01951},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Atmospheres},
number = {D11},
pages = {22831},
publisher = {American Geophysical Union},
title = {{Evidence for interannual variability of the carbon cycle from the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory Global Air Sampling Network}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/94JD01951 http://doi.wiley.com/10.1029/94JD01951},
volume = {99},
year = {1994}
}
@article{Cooper1983a,
abstract = {A general model is developed to relate average carbon storage over the lifetime of a forest managed for sustained yield to the maximum biomass of the same forest at maturity. If a forest is managed for maximum sustained yield of biomass, mean lifetime carbon storage is about one-third that at maturity. When accumulation and decomposition of detritus after harvest are added, the fraction is about 0.5 in temperate deciduous forests, less in the tropics, and more in boreal forests. Harvest at financial maturity, by shortening the rotation, disproportionately reduces lifetime carbon storage, to perhaps 0.2 of the maximum. Nontimber values may affect carbon storage either positively or negatively. Forest regrowth and multispecies agricultural systems that include trees may account for more carbon storage in the tropics than is sometimes assumed.- Author},
author = {Cooper, C. F.},
doi = {10.1139/x83-022},
issn = {00455067},
journal = {Canadian Journal of Forest Research},
number = {1},
pages = {155--166},
title = {{Carbon storage in managed forests}},
volume = {13},
year = {1983}
}
@article{CotoviczJr.2015,
abstract = {Abstract. In contrast to its small surface area, the coastal zone plays a disproportionate role in the global carbon cycle. Carbon production, transformation, emission and burial rates at the land–ocean interface are significant at the global scale but still poorly known, especially in tropical regions. Surface water pCO2 and ancillary parameters were monitored during nine field campaigns between April 2013 and April 2014 in Guanabara Bay, a tropical eutrophic to hypertrophic semi-enclosed estuarine embayment surrounded by the city of Rio de Janeiro, southeast Brazil. Water pCO2 varied between 22 and 3715 ppmv in the bay, showing spatial, diurnal and seasonal trends that mirrored those of dissolved oxygen (DO) and chlorophyll a (Chl a). Marked pCO2 undersaturation was prevalent in the shallow, confined and thermally stratified waters of the upper bay, whereas pCO2 oversaturation was restricted to sites close to the small river mouths and small sewage channels, which covered only 10 {\%} of the bay's area. Substantial daily variations in pCO2 (up to 395 ppmv between dawn and dusk) were also registered and could be integrated temporally and spatially for the establishment of net diurnal, seasonal and annual CO2 fluxes. In contrast to other estuaries worldwide, Guanabara Bay behaved as a net sink of atmospheric CO2, a property enhanced by the concomitant effects of strong radiation intensity, thermal stratification, and high availability of nutrients, which promotes phytoplankton development and net autotrophy. The calculated CO2 fluxes for Guanabara Bay ranged between −9.6 and −18.3 mol C m−2 yr−1, of the same order of magnitude as the organic carbon burial and organic carbon inputs from the watershed. The positive and high net community production (52.1 mol C m−2 yr−1) confirms the high carbon production in the bay. This autotrophic metabolism is apparently enhanced by eutrophication. Our results show that global CO2 budgetary assertions still lack information on tropical, marine-dominated estuarine systems, which are affected by thermal stratification and eutrophication and behave specifically with respect to atmospheric CO2.},
author = {{Cotovicz Jr.}, L C and Knoppers, B A and Brandini, N and {Costa Santos}, S J and Abril, G},
doi = {10.5194/bg-12-6125-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {20},
pages = {6125--6146},
publisher = {Copernicus Publications},
title = {{A strong CO2 sink enhanced by eutrophication in a tropical coastal embayment (Guanabara Bay, Rio de Janeiro, Brazil)}},
url = {http://www.biogeosciences.net/12/6125/2015/},
volume = {12},
year = {2015}
}
@article{Cotovicz2018,
abstract = {We investigate the carbon dynamics in Guanabara Bay, an eutrophic tropical coastal embayment surrounded by the megacity of Rio de Janeiro (southeast coast of Brazil). Nine sampling campaigns were conducted for dissolved, particulate and total organic carbon (DOC, POC and TOC), dissolved inorganic carbon (DIC), partial pressure of CO2 (pCO2), chlorophyll a (Chl a), pheo-pigments and ancillary parameters. Highest DOC, POC and Chl a concentrations were found in confined-shallow regions of the bay during the summer period with strong pCO2 undersaturation, and DOC reached 82 mg L−1, POC 152 mg L−1, and Chl a 800 {\$}\mu{\$}g L−1. Spatially and temporally, POC and DOC concentrations varied positively with total pigments, and negatively with DIC. Strong linear correlations between these parameters indicate that the production of TOC translates to an equivalent uptake in DIC, with 85{\%} of the POC and about 50{\%} of the DOC being of phytoplanktonic origin. Despite the shallow depths of the bay, surface waters were enriched in POC and DOC relative to bottom waters in periods of high thermohaline stratification. The seasonal accumulation of phytoplankton-derived TOC in the surface waters reached about 105 g C m−2 year−1, representing between 8 and 40{\%} of the net primary production. The calculated turnover time of organic carbon was 117 and 34 days during winter and summer, respectively. Our results indicate that eutrophication of coastal bays in the tropics can generate large stocks of planktonic biomass and detrital organic carbon which are permanently being produced and partially degraded and buried in sediments.},
author = {{Cotovicz Jr.}, Luiz C and Knoppers, Bastiaan A and Brandini, Nilva and Poirier, Dominique and {Costa Santos}, Suzan J and Cordeiro, Renato C and Abril, Gwena{\"{e}}l},
doi = {10.1007/s10533-017-0405-y},
issn = {0168-2563},
journal = {Biogeochemistry},
month = {jan},
number = {1-2},
pages = {1--14},
title = {{Predominance of phytoplankton-derived dissolved and particulate organic carbon in a highly eutrophic tropical coastal embayment (Guanabara Bay, Rio de Janeiro, Brazil)}},
url = {https://doi.org/10.1007/s10533-017-0405-y http://link.springer.com/10.1007/s10533-017-0405-y},
volume = {137},
year = {2018}
}
@article{Covey2019,
author = {Covey, Kristofer R. and Megonigal, J. Patrick},
doi = {10.1111/nph.15624},
issn = {0028-646X},
journal = {New Phytologist},
month = {apr},
number = {1},
pages = {35--51},
title = {{Methane production and emissions in trees and forests}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.15624},
volume = {222},
year = {2019}
}
@article{Cowtan2014a,
author = {Cowtan, Kevin and Way, Robert G.},
doi = {10.1002/qj.2297},
issn = {00359009},
journal = {Quarterly Journal of the Royal Meteorological Society},
keywords = {coverage bias,instrumental temperature record,temperature trends},
month = {jul},
number = {683},
pages = {1935--1944},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Coverage bias in the HadCRUT4 temperature series and its impact on recent temperature trends}},
url = {http://doi.wiley.com/10.1002/qj.2297},
volume = {140},
year = {2014}
}
@article{Cox:2000,
abstract = {The continued increase in the atmospheric concentration of carbon dioxide due to anthropogenic emissions is predicted to lead to significant changes in climate(1). About half of the current emissions are being absorbed by the ocean and by land ecosystems(2), but this absorption is sensitive to climate(3,4) as well as to atmospheric carbon dioxide concentrations(5), creating a feedback loop. General circulation models have generally excluded the feedback between climate and the biosphere, using static vegetation distributions and CO2 concentrations from simple carbon-cycle models that do not include climate change(6). Here we present results from a fully coupled, three-dimensional carbon-climate model, indicating that carbon-cycle feedbacks could significantly accelerate climate change over the twenty-first century. We rnd that under a 'business as usual' scenario, the terrestrial biosphere acts as an overall carbon sink until about 2050, but turns into a source thereafter. By 2100, the ocean uptake rate of 5 Gt Cyr(-1) is balanced by the terrestrial carbon source, and atmospheric CO2 concentrations are 250 p.p.m.v. higher in our fully coupled simulation than in uncoupled carbon models(2), resulting in a global-mean warming of 5.5 K, as compared to 4 K without the carbon-cycle feedback.},
author = {Cox, Peter M and Betts, Richard A and Jones, Chris D and Spall, Steven A and Totterdell, Ian J},
doi = {10.1038/35041539},
issn = {0028-0836},
journal = {Nature},
month = {nov},
number = {6809},
pages = {184--187},
title = {{Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model}},
url = {https://www.nature.com/articles/35041539 http://www.nature.com/articles/35041539},
volume = {408},
year = {2000}
}
@article{Cox2013,
abstract = {The release of carbon from tropical forests may exacerbate future climate change, but the magnitude of the effect in climate models remains uncertain. Coupled climate-carbon-cycle models generally agree that carbon storage on land will increase as a result of the simultaneous enhancement of plant photosynthesis and water use efficiency under higher atmospheric CO(2) concentrations, but will decrease owing to higher soil and plant respiration rates associated with warming temperatures. At present, the balance between these effects varies markedly among coupled climate-carbon-cycle models, leading to a range of 330 gigatonnes in the projected change in the amount of carbon stored on tropical land by 2100. Explanations for this large uncertainty include differences in the predicted change in rainfall in Amazonia and variations in the responses of alternative vegetation models to warming. Here we identify an emergent linear relationship, across an ensemble of models, between the sensitivity of tropical land carbon storage to warming and the sensitivity of the annual growth rate of atmospheric CO(2) to tropical temperature anomalies. Combined with contemporary observations of atmospheric CO(2) concentration and tropical temperature, this relationship provides a tight constraint on the sensitivity of tropical land carbon to climate change. We estimate that over tropical land from latitude 30° north to 30° south, warming alone will release 53 ± 17 gigatonnes of carbon per kelvin. Compared with the unconstrained ensemble of climate-carbon-cycle projections, this indicates a much lower risk of Amazon forest dieback under CO(2)-induced climate change if CO(2) fertilization effects are as large as suggested by current models. Our study, however, also implies greater certainty that carbon will be lost from tropical land if warming arises from reductions in aerosols or increases in other greenhouse gases.},
author = {Cox, Peter M. and Pearson, David and Booth, Ben B. and Friedlingstein, Pierre and Huntingford, Chris and Jones, Chris D. and Luke, Catherine M.},
doi = {10.1038/nature11882},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7437},
pages = {341--344},
pmid = {23389447},
publisher = {Nature Publishing Group},
title = {{Sensitivity of tropical carbon to climate change constrained by carbon dioxide variability}},
type = {Journal Article},
url = {https://www.nature.com/articles/nature11882},
volume = {494},
year = {2013}
}
@article{Cox2004,
abstract = {The first GCM climate change projections to include dynamic vegetation and an interactive carbon cycle produced a very significant amplification of global warming over the 21st century. Under the IS92a ``business as usual'' emissions scenario CO2 concentrations reached about 980{\{}$\backslash$thinspace{\}}ppmv by 2100, which is about 280{\{}$\backslash$thinspace{\}}ppmv higher than when these feedbacks were ignored. The major contribution to the increased CO2 arose from reductions in soil carbon because global warming is assumed to accelerate respiration. However, there was also a lesser contribution from an alarming loss of the Amazonian rainforest. This paper describes the phenomenon of Amazonian forest dieback under elevated CO2 in the Hadley Centre climate-carbon cycle model.},
annote = {added by A.Eliseev 25.01.2019},
author = {Cox, P M and Betts, R A and Collins, M and Harris, P P and Huntingford, C and Jones, C D},
doi = {10.1007/s00704-004-0049-4},
issn = {0177-798X},
journal = {Theoretical and Applied Climatology},
month = {jun},
number = {1-3},
pages = {137--156},
title = {{Amazonian forest dieback under climate-carbon cycle projections for the 21st century}},
url = {https://doi.org/10.1007/s00704-004-0049-4 http://link.springer.com/10.1007/s00704-004-0049-4},
volume = {78},
year = {2004}
}
@article{Cox2019,
author = {Cox, Peter M.},
doi = {10.1007/s40641-019-00141-y},
issn = {2198-6061},
journal = {Current Climate Change Reports},
month = {dec},
number = {4},
pages = {275--281},
title = {{Emergent constraints on climate–carbon cycle feedbacks}},
url = {http://link.springer.com/10.1007/s40641-019-00141-y},
volume = {5},
year = {2019}
}
@article{Crawford2017,
author = {Crawford, John T. and Loken, Luke C. and West, William E. and Crary, Benjamin and Spawn, Seth A. and Gubbins, Nicholas and Jones, Stuart E. and Striegl, Robert G. and Stanley, Emily H.},
doi = {10.1002/2016JG003698},
issn = {21698953},
journal = {Journal of Geophysical Research: Biogeosciences},
month = {may},
number = {5},
pages = {1036--1048},
title = {{Spatial heterogeneity of within-stream methane concentrations}},
url = {http://doi.wiley.com/10.1002/2016JG003698},
volume = {122},
year = {2017}
}
@article{Creese2014,
abstract = {The stomatal behavior of ferns provides an excellent system for disentangling responses to different environmental signals, which balance carbon gain against water loss. Here, we measured responses of stomatal conductance (gs) to irradiance, CO2, and vapor pressure deficit (VPD) for 13 phylogenetically diverse species native to open and shaded habitats, grown under high- and low-irradiance treatments. We tested two main hypotheses: that plants adapted and grown in high-irradiance environments would have greater responsiveness to all stimuli given higher flux rates; and that species' responsiveness to different factors would be correlated because of the relative simplicity of fern stomatal control. We found that species with higher light-saturated gs had larger responses, and that plants grown under high irradiance were more responsive to all stimuli. Open habitat species showed greater responsiveness to irradiance and CO2, but lower responsiveness to VPD; a case of plasticity and adaptation tending in different directions. Responses of gs to irradiance and VPD were positively correlated across species, but CO2 responses were independent and highly variable. The novel finding of correlations among stomatal responses to different stimuli suggests coordination of hydraulic and photosynthetic signaling networks modulating fern stomatal responses, which show distinct optimization at growth and evolutionary time-scales. {\textcopyright} 2014 New Phytologist Trust.},
author = {Creese, Chris and Oberbauer, Steve and Rundel, Phil and Sack, Lawren},
doi = {10.1111/nph.12922},
issn = {14698137},
journal = {New Phytologist},
keywords = {Guard cells,Humidity,Light response,Pteridophytes,Vapor pressure deficit (VPD),Water use},
number = {1},
pages = {92--104},
pmid = {25077933},
title = {{Are fern stomatal responses to different stimuli coordinated? Testing responses to light, vapor pressure deficit, and CO2 for diverse species grown under contrasting irradiances}},
volume = {204},
year = {2014}
}
@article{Crichton2016,
abstract = {The atmospheric concentration of CO2 increased from 190 to 280 ppm between the last glacial maximum 21,000 years ago and the pre-industrial era1, 2. This CO2 rise and its timing have been linked to changes in the Earth's orbit, ice sheet configuration and volume, and ocean carbon storage2, 3. The ice-core record of $\delta$13CO2 (refs 2,4) in the atmosphere can help to constrain the source of carbon, but previous modelling studies have failed to capture the evolution of $\delta$13CO2 over this period5. Here we show that simulations of the last deglaciation that include a permafrost carbon component can reproduce the ice core records between 21,000 and 10,000 years ago. We suggest that thawing permafrost, due to increasing summer insolation in the northern hemisphere, is the main source of CO2 rise between 17,500 and 15,000 years ago, a period sometimes referred to as the Mystery Interval6. Together with a fresh water release into the North Atlantic, much of the CO2 variability associated with the B{\o}lling-Allerod/Younger Dryas period {\~{}}15,000 to {\~{}}12,000 years ago can also be explained. In simulations of future warming we find that the permafrost carbon feedback increases global mean temperature by 10–40{\%} relative to simulations without this feedback, with the magnitude of the increase dependent on the evolution of anthropogenic carbon emissions.},
author = {Crichton, K A and Bouttes, N and Roche, D M and Chappellaz, J and Krinner, G},
doi = {10.1038/ngeo2793},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {sep},
number = {9},
pages = {683--686},
publisher = {Nature Publishing Group},
title = {{Permafrost carbon as a missing link to explain CO2 changes during the last deglaciation}},
url = {http://dx.doi.org/10.1038/ngeo2793 http://10.0.4.14/ngeo2793 https://www.nature.com/articles/ngeo2793{\#}supplementary-information http://www.nature.com/articles/ngeo2793},
volume = {9},
year = {2016}
}
@article{Crippa2020,
author = {Crippa, Monica and Solazzo, Efisio and Huang, Ganlin and Guizzardi, Diego and Koffi, Ernest and Muntean, Marilena and Schieberle, Christian and Friedrich, Rainer and Janssens-Maenhout, Greet},
doi = {10.1038/s41597-020-0462-2},
issn = {2052-4463},
journal = {Scientific Data},
month = {dec},
number = {1},
pages = {121},
title = {{High resolution temporal profiles in the Emissions Database for Global Atmospheric Research}},
url = {http://www.nature.com/articles/s41597-020-0462-2},
volume = {7},
year = {2020}
}
@article{Cronin2019,
abstract = {Turbulent and radiative exchanges of heat between the ocean and atmosphere (hereafter heat fluxes), ocean surface wind stress, and state variables used to estimate them, are Essential Ocean Variables (EOVs) and Essential Climate Variables (ECVs) influencing weather and climate. This paper describes an observational strategy for producing 3-hourly, 25-km (and an aspirational goal of hourly at 10-km) heat flux and wind stress fields over the global, ice-free ocean with breakthrough 1-day random uncertainty of 15 W m-2 and a bias of less than 5 W m-2. At present this accuracy target is met only at OceanSITES reference station moorings and research vessels (RVs) that follow best practices. To meet these targets globally, in the next decade, satellite-based observations must be optimized for boundary layer measurements of air temperature, humidity, sea surface temperature, and ocean wind stress. In order to tune and validate these satellite measurements, a complementary global in situ flux array, built around an expanded OceanSITES network of time series reference station moorings, is also needed. The array would include 500 - 1000 measurement platforms, including autonomous surface vehicles, moored and drifting buoys, RVs, the existing OceanSITES network of 22 flux sites, and new OceanSITES expanded in 19 key regions. This array would be globally distributed, with 1 - 3 measurement platforms in each nominal 10° by 10° boxes. These improved moisture and temperature profiles and surface data, if assimilated into Numerical Weather Prediction (NWP) models, would lead to better representation of cloud formation processes, improving state variables and surface radiative and turbulent fluxes from these models. The in situ flux array provides globally distributed measurements and metrics for satellite algorithm development, product validation, and for improving satellite-based, NWP and blended flux products. In addition, some of these flux platforms will also measure direct turbulent fluxes, which can be used to improve algorithms for computation of air-sea exchange of heat and momentum in flux products and models. With these improved air-sea fluxes, the ocean's influence on the atmosphere will be better quantified and lead to improved long-term weather forecasts, seasonal-interannual-decadal climate predictions, and regional climate projections.},
author = {Cronin, Meghan F. and Gentemann, Chelle L. and Edson, James B. and Ueki, Iwao and Bourassa, Mark and Brown, Shannon and Clayson, Carol A. and Fairall, Chris and {T. Farrar}, J. and Gille, Sarah T. and Gulev, Sergey and Josey, Simon and Kato, Sieji and Katsumata, Masaki and Kent, Elizabeth C. and Krug, Marjolaine and Minnett, Peter J. and Parfitt, Rhys and Pinker, Rachel T. and Stackhouse, Paul W. and Swart, Sebastiaan and Tomita, Hiroyuki and Vandemark, Doug and Weller, Robert A. and Yoneyama, Kunio and Yu, Lisan and Zhang, Dongxiao},
doi = {10.3389/fmars.2019.00430},
issn = {22967745},
journal = {Frontiers in Marine Science},
keywords = {Air-sea heat flux,Autonomous surface vehicle,ICOADS,Latent heat flux,Ocean wind stress,OceanSites,Satellite-based ocean monitoring system,Surface radiation},
month = {jul},
pages = {430},
publisher = {Frontiers Media S.A.},
title = {{Air–sea fluxes with a focus on heat and momentum}},
url = {www.frontiersin.org},
volume = {6},
year = {2019}
}
@article{Cross2018,
abstract = {Ocean acidification (OA), driven by rising anthropogenic carbon dioxide (CO2), is rapidly advancing in the Pacific Arctic Region (PAR), producing conditions newly corrosive to biologically important carbonate minerals like aragonite. Naturally short linkages across the PAR food web mean that species-specific acidification stress can be rapidly transmitted across multiple trophic levels, resulting in widespread impacts. Therefore, it is critical to understand the formation, transport, and persistence of acidified conditions in the PAR in order to better understand and project potential impacts to this delicately balanced ecosystem. Here, we synthesize data from process studies across the PAR to show the formation of corrosive conditions in colder, denser winter-modified Pacific waters over shallow shelves, resulting from the combination of seasonal terrestrial and marine organic matter respiration with anthropogenic CO2. When these waters are subsequently transported off the shelf, they acidify the Pacific halocline. We estimate that Barrow Canyon outflow delivers {\~{}}2.24 Tg C yr-1 to the Arctic Ocean through corrosive winter water transport. This synthesis also allows the combination of spatial data with temporal data to show the persistence of these conditions in halocline waters. For example, one study in this synthesis indicated that 0.5–1.7 Tg C yr-1 may be returned to the atmosphere via air-sea gas exchange of CO2 during upwelling events along the Beaufort Sea shelf that bring Pacific halocline waters to the ocean surface. The loss of CO2 during these events is more than sufficient to eliminate corrosive conditions in the upwelled Pacific halocline waters. However, corresponding moored and discrete data records indicate that potentially corrosive Pacific waters are present in the Beaufort shelfbreak jet during 80{\%} of the year, indicating that the persistence of acidified waters in the Pacific halocline far outweighs any seasonal mitigation from upwelling. Across the datasets in this large-scale synthesis, we estimate that the persistent corrosivity of the Pacific halocline is a recent phenomenon that appeared between 1975 and 1985. Over that short time, these potentially corrosive waters originating over the continental shelves have been observed as far as the entrances to Amundsen Gulf and M'Clure Strait in the Canadian Arctic Archipelago. The formation and transport of corrosive waters on the Pacific Arctic shelves may have widespread impact on the Arctic biogeochemical system and food web reaching all the way to the North Atlantic.},
author = {Cross, Jessica N and Mathis, Jeremy T and Pickart, Robert S and Bates, Nicholas R},
doi = {10.1016/j.dsr2.2018.05.020},
issn = {0967-0645},
journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
keywords = {Arctic Ocean,Arctic Rivers,Beaufort Sea,Biological vulnerability,Chukchi Sea,Community resilience,East Siberian Sea,Ocean acidification,Pacific Arctic,Respiration,Sea Ice,Transport,Upwelling},
pages = {67--81},
title = {{Formation and transport of corrosive water in the Pacific Arctic region}},
url = {http://www.sciencedirect.com/science/article/pii/S0967064518301231},
volume = {152},
year = {2018}
}
@article{Crowley2015,
author = {Crowley, J. W. and Katz, R. F. and Huybers, P. and Langmuir, C. H. and Park, S.-H.},
doi = {10.1126/science.1261508},
issn = {0036-8075},
journal = {Science},
month = {mar},
number = {6227},
pages = {1237--1240},
title = {{Glacial cycles drive variations in the production of oceanic crust}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1261508},
volume = {347},
year = {2015}
}
@article{Cui2011,
abstract = {The transient global warming event known as the Palaeocene–Eocene Thermal Maximum occurred about 55.9 Myr ago. The warming was accompanied by a rapid shift in the isotopic signature of sedimentary carbonates, suggesting that the event was triggered by a massive release of carbon to the ocean–atmosphere system. However, the source, rate of emission and total amount of carbon involved remain poorly constrained. Here we use an expanded marine sedimentary section from Spitsbergen to reconstruct the carbon isotope excursion as recorded in marine organic matter. We find that the total magnitude of the carbon isotope excursion in the ocean–atmosphere system was about 4‰. We then force an Earth system model of intermediate complexity to conform to our isotope record, allowing us to generate a continuous estimate of the rate of carbon emissions to the atmosphere. Our simulations show that the peak rate of carbon addition was probably in the range of 0.3–1.7 Pg C yr−1, much slower than the present rate of carbon emissions.},
author = {Cui, Ying and Kump, Lee R. and Ridgwell, Andy J. and Charles, Adam J. and Junium, Christopher K. and Diefendorf, Aaron F. and Freeman, Katherine H. and Urban, Nathan M. and Harding, Ian C.},
doi = {10.1038/ngeo1179},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jul},
number = {7},
pages = {481--485},
title = {{Slow release of fossil carbon during the Palaeocene–Eocene Thermal Maximum}},
url = {http://www.nature.com/articles/ngeo1179},
volume = {4},
year = {2011}
}
@article{Cui2018,
abstract = {The early Paleogene greenhouse climate is punctuated by a series of extreme global warming events known as hyperthermals that are associated with massive additions of carbon to the ocean-atmosphere system. However, no existing proxies have suitable resolution to capture the change in atmospheric carbon dioxide (pCO2) across these events. Here, we reconstruct a nearly continuous record of pCO2 during the early Paleogene based on changes in terrestrial carbon isotope discrimination calculated from published high-resolution marine and terrestrial carbon isotope records. We calculate relatively stable baseline pCO2 = 569 + 250/−146 ppmv with significant increases in pCO2 at each of four hyperthermals. These background levels are significantly higher than most existing proxy estimates, but still lower than levels commonly assumed within carbon cycle models. Based on the pCO2 levels we calculate across each hyperthermal, we show that these events are associated with carbon additions most likely dominated by terrestrial organic matter oxidation or mantle-derived CO2. By matching the new high-resolution pCO2 data with global temperature data we calculate Earth-system sensitivity of {\~{}}0.8 to 1.6 KW−1 m2 across these hyperthermals. The slightly elevated ESS during the PETM and H2 suggests positive feedbacks through other greenhouse gases, changes in vegetation and/or oxidation of organic matter/methane may have amplified the temperature response to CO2 addition.},
author = {Cui, Ying and Schubert, Brian A.},
doi = {10.1016/j.gloplacha.2018.08.011},
issn = {09218181},
journal = {Global and Planetary Change},
keywords = {Carbon isotopes,Earth-system sensitivity,High-resolution pCO2,Hyperthermals,PETM},
number = {February},
pages = {120--125},
publisher = {Elsevier},
title = {{Towards determination of the source and magnitude of atmospheric pCO2 change across the early Paleogene hyperthermals}},
url = {https://doi.org/10.1016/j.gloplacha.2018.08.011},
volume = {170},
year = {2018}
}
@article{Cummins2020,
abstract = {Oceanographic observations collected at Station P (145°W, 50°N) in the northeast Pacific extend for over six decades, representing one of the longest available records of subsurface ocean water properties. As such, this record is well suited to examine secular trends in properties of the subarctic waters of the North Pacific. In this paper, previously published trends are reviewed and updated, based on a newly compiled dataset for the station. Vertically integrated quantities such as ocean heat content and steric height are examined, as well as local water properties through the water column including temperature, salinity and, in particular, oxygen. Consideration is also given to upper-ocean stratification, along with depths of the mixed layer and isopycnal surfaces. The results provide a comprehensive view of long-term changes to ocean conditions in the deep waters of the subarctic Pacific. Increases in 0/2000 dbar ocean heat content and steric height are evident, due primarily to ocean warming through the upper 500 dbar of the water column. However, about a third of the overall 0/2000 dbar steric height trend is due to halosteric effects. A significant freshening trend is evident through the upper layer to the top of the permanent pycnocline. Significant changes are also found below the permanent pycnocline, in particular warming on isopycnal surfaces along with downward migration of isopycnals. On the other hand, no robust trend emerges in the strength of the stratification associated with the permanent pycnocline, a result that likely has implications for turbulent exchanges between the surface mixed layer and the deep ocean, including the supply of nutrients to the euphotic zone. Statistically significant declines in dissolved oxygen are observed on isopycnals below the pycnocline, down to great depth. Column-integrated dissolved oxygen has declined at a rate of 0.72 mol m−2 y−1, representing a net loss over six decades of 11.7 ± 3.5{\%} in total oxygen content per square metre. This is substantially greater than the global average of 2{\%}, underscoring the northeast Pacific as a region of comparatively rapid deoxygenation. Changes in solubility due to local warming have made only a minor contribution to the observed decline.},
author = {Cummins, Patrick F. and Ross, Tetjana},
doi = {10.1016/j.pocean.2020.102329},
issn = {00796611},
journal = {Progress in Oceanography},
month = {jul},
pages = {102329},
publisher = {Elsevier Ltd},
title = {{Secular trends in water properties at Station P in the northeast Pacific: An updated analysis}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0079661120300689},
volume = {186},
year = {2020}
}
@article{DOlivo2015,
abstract = {Abstract. The boron isotopic ({\&}delta;11Bcarb) compositions of long-lived Porites coral are used to reconstruct reef-water pH across the central Great Barrier Reef (GBR) and assess the impact of river runoff on inshore reefs. For the period from 1940 to 2009, corals from both inner- and mid-shelf sites exhibit the same overall decrease in {\&}delta;11Bcarb of 0.086 ± 0.033{\&}permil; per decade, equivalent to a decline in seawater pH (pHsw) of {\~{}}0.017 ± 0.007 pH units per decade. This decline is consistent with the long-term effects of ocean acidification based on estimates of CO2 uptake by surface waters due to rising atmospheric levels. We also find that, compared to the mid-shelf corals, the {\&}delta;11Bcarb compositions of inner-shelf corals subject to river discharge events have higher and more variable values, and hence higher inferred pHsw values. These higher {\&}delta;11Bcarb values of inner-shelf corals are particularly evident during wet years, despite river waters having lower pH. The main effect of river discharge on reef-water carbonate chemistry thus appears to be from reduced aragonite saturation state and higher nutrients driving increased phytoplankton productivity, resulting in the drawdown of pCO2 and increase in pHsw. Increased primary production therefore has the potential to counter the more transient effects of low-pH river water (pHrw) discharged into near-shore environments. Importantly, however, inshore reefs also show a consistent pattern of sharply declining coral growth that coincides with periods of high river discharge. This occurs despite these reefs having higher pHsw, demonstrating the overriding importance of local reef-water quality and reduced aragonite saturation state on coral reef health.},
author = {D'Olivo, J. P. and McCulloch, M. T. and Eggins, S. M. and Trotter, J.},
doi = {10.5194/bg-12-1223-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {feb},
number = {4},
pages = {1223--1236},
title = {{Coral records of reef-water pH across the central Great Barrier Reef, Australia: assessing the influence of river runoff on inshore reefs}},
url = {https://www.biogeosciences.net/12/1223/2015/},
volume = {12},
year = {2015}
}
@article{Durr2011a,
author = {D{\"{u}}rr, Hans H. and Laruelle, Goulven G. and Kempen, Cheryl M. and Slomp, Caroline P. and Meybeck, Michel and Middelkoop, Hans},
doi = {10.1007/s12237-011-9381-y},
issn = {1559-2723},
journal = {Estuaries and Coasts},
month = {mar},
number = {3},
pages = {441--458},
title = {{Worldwide typology of nearshore coastal systems: defining the estuarine filter of river inputs to the oceans}},
volume = {34},
year = {2011}
}
@article{Dagon2019,
author = {Dagon, Katherine and Schrag, Daniel P},
doi = {10.1007/s10584-019-02387-9},
issn = {0165-0009},
journal = {Climatic Change},
month = {mar},
number = {1-2},
pages = {235--251},
publisher = {Climatic Change},
title = {{Quantifying the effects of solar geoengineering on vegetation}},
url = {http://link.springer.com/10.1007/s10584-019-02387-9},
volume = {153},
year = {2019}
}
@article{Dalsøren2016,
abstract = {Observations at surface sites show an increase in global mean surface methane (CH4) of about 180 parts per billion (ppb) (above 10 {\%}) over the period 1984–2012. Over this period there are large fluctuations in the annual growth rate. In this work, we investigate the atmospheric CH4 evolution over the period 1970–2012 with the Oslo CTM3 global chemical transport model (CTM) in a bottom-up approach. We thoroughly assess data from surface measurement sites in international networks and select a subset suited for comparisons with the output from the CTM. We compare model results and observations to understand causes for both long-term trends and short-term variations. Employing Oslo CTM3 we are able to reproduce the seasonal and year-to-year variations and shifts between years with consecutive growth and stagnation, both at global and regional scales. The overall CH4 trend over the period is reproduced, but for some periods the model fails to reproduce the strength of the growth. The model overestimates the observed growth after 2006 in all regions. This seems to be explained by an overly strong increase in anthropogenic emissions in Asia, having global impact. Our findings confirm other studies questioning the timing or strength of the emission changes in Asia in the EDGAR v4.2 emission inventory over recent decades. The evolution of CH4 is not only controlled by changes in sources, but also by changes in the chemical loss in the atmosphere and soil uptake. The atmospheric CH4 lifetime is an indicator of the CH4 loss. In our simulations, the atmospheric CH4 lifetime decreases by more than 8 {\%} from 1970 to 2012, a significant reduction of the residence time of this important greenhouse gas. Changes in CO and NOx emissions, specific humidity, and ozone column drive most of this, and we provide simple prognostic equations for the relations between those and the CH4 lifetime. The reduced lifetime results in substantial growth in the chemical CH4 loss (relative to its burden) and dampens the CH4 growth.},
author = {Dals{\o}ren, Stig B. and Myhre, Cathrine L. and Myhre, Gunnar and Gomez-Pelaez, Angel J. and S{\o}vde, Ole A. and Isaksen, Ivar S. A. and Weiss, Ray F. and Harth, Christina M.},
doi = {10.5194/acp-16-3099-2016},
journal = {Atmospheric Chemistry and Physics},
month = {mar},
number = {5},
pages = {3099--3126},
title = {{Atmospheric methane evolution the last 40 years}},
url = {https://www.atmos-chem-phys.net/16/3099/2016/},
volume = {16},
year = {2016}
}
@article{DANESHVAR2017184,
author = {Daneshvar, Fariborz and Nejadhashemi, A Pouyan and Adhikari, Umesh and Elahi, Behin and Abouali, Mohammad and Herman, Matthew R and Martinez-Martinez, Edwin and Calappi, Timothy J and Rohn, Bridget G},
doi = {10.1016/j.jenvman.2017.01.059},
issn = {03014797},
journal = {Journal of Environmental Management},
keywords = {Phosphorus,SUSTAIN,SWAT,Saginaw,VIKOR,Wetland},
month = {may},
pages = {184--196},
title = {{Evaluating the significance of wetland restoration scenarios on phosphorus removal}},
url = {http://www.sciencedirect.com/science/article/pii/S0301479717300774 https://linkinghub.elsevier.com/retrieve/pii/S0301479717300774},
volume = {192},
year = {2017}
}
@article{Dargie2017,
abstract = {Peatlands are carbon-rich ecosystems that cover just three per cent of Earth's land surface1, but store one-third of soil carbon2. Peat soils are formed by the build-up of partially decomposed organic matter under waterlogged anoxic conditions. Most peat is found in cool climatic regions where unimpeded decomposition is slower, but deposits are also found under some tropical swamp forests2,3. Here we present field measurements from one of the world's most extensive regions of swamp forest, the Cuvette Centrale depression in the central Congo Basin4. We find extensive peat deposits beneath the swamp forest vegetation (peat defined as material with an organic matter content of at least 65 per cent to a depth of at least 0.3 metres). Radiocarbon dates indicate that peat began accumulating from about 10,600 years ago, coincident with the onset of more humid conditions in central Africa at the beginning of the Holocene5. The peatlands occupy large interfluvial basins, and seem to be largely rain-fed and ombrotrophic-like (of low nutrient status) systems. Although the peat layer is relatively shallow (with a maximum depth of 5.9 metres and a median depth of 2.0 metres), by combining in situ and remotely sensed data, we estimate the area of peat to be approximately 145,500 square kilometres (95 per cent confidence interval of 131,900-156,400 square kilometres), making the Cuvette Centrale the most extensive peatland complex in the tropics. This area is more than five times the maximum possible area reported for the Congo Basin in a recent synthesis of pantropical peat extent2. We estimate that the peatlands store approximately 30.6 petagrams (30.6 × 1015 grams) of carbon belowground (95 per cent confidence interval of 6.3-46.8 petagrams of carbon)-a quantity that is similar to the above-ground carbon stocks of the tropical forests of the entire Congo Basin6. Our result for the Cuvette Centrale increases the best estimate of global tropical peatland carbon stocks by 36 per cent, to 104.7 petagrams of carbon (minimum estimate of 69.6 petagrams of carbon; maximum estimate of 129.8 petagrams of carbon). This stored carbon is vulnerable to land-use change and any future reduction in precipitation7,8.},
author = {Dargie, Greta C. and Lewis, Simon L. and Lawson, Ian T. and Mitchard, Edward T.A. and Page, Susan E. and Bocko, Yannick E. and Ifo, Suspense A.},
doi = {10.1038/nature21048},
issn = {14764687},
journal = {Nature},
number = {7639},
title = {{Age, extent and carbon storage of the central Congo Basin peatland complex}},
volume = {542},
year = {2017}
}
@article{Davidson2009,
abstract = {Atmospheric concentrations of nitrous oxide, a greenhouse gas, have increased since 1860. A regression model indicates that conversion of 2{\%} of manure nitrogen and 2.5{\%} of fertilizer nitrogen could explain the pattern of increasing nitrous oxide concentrations between 1860 and 2005, including a rise in the rate of increase around 1960.},
author = {Davidson, Eric A.},
doi = {10.1038/ngeo608},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {sep},
number = {9},
pages = {659--662},
publisher = {Nature Publishing Group},
title = {{The contribution of manure and fertilizer nitrogen to atmospheric nitrous oxide since 1860}},
url = {http://www.nature.com/articles/ngeo608},
volume = {2},
year = {2009}
}
@article{Davies-Barnard,
author = {Davies-Barnard, Taraka and Meyerholt, Johannes and Zaehle, S{\"{o}}nke and Friedlingstein, Pierre and Brovkin, Victor and Fan, Yuanchao and Fisher, Rosie A. and Jones, Chris D. and Lee, Hanna and Peano, Daniele and Smith, Benjamin and W{\aa}rlind, David and Wiltshire, Andy J.},
doi = {10.5194/bg-17-5129-2020},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {20},
pages = {5129--5148},
title = {{Nitrogen cycling in CMIP6 land surface models: progress and limitations}},
url = {https://bg.copernicus.org/articles/17/5129/2020/},
volume = {17},
year = {2020}
}
@incollection{IPCC2018,
author = {de Coninck, H. and Revi, A. and Babiker, M. and Bertoldi, P. and Buckeridge, M. and Cartwright, A. and Dong, W. and Ford, J. and Fuss, S. and Hourcade, J.-C. and Ley, D. and Mechler, R. and Newman, P. and Revokatova, A. and Schultz, S. and Steg, L. and Sugiyama, T.},
booktitle = {Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change,},
chapter = {4},
editor = {Masson-Delmotte, V. and Zhai, P. and P{\"{o}}rtner, H.-O. and Roberts, D. and Skea, J. and Shukla, P.R. and Pirani, A. and Moufouma-Okia, W. and P{\'{e}}an, C. and Pidcock, R. and Connors, S. and Matthews, J.B.R. and Chen, Y. and Zhou, X. and Gomis, M.I. and Lonnoy, E. and Maycock, T. and Tignor, M. and Waterfield, T.},
pages = {313--444},
publisher = {In Press},
title = {{Strengthening and Implementing the Global Response}},
url = {https://www.ipcc.ch/sr15/chapter/chapter-4},
year = {2018}
}
@article{De-Kauwe:2014,
abstract = {* Elevated atmospheric CO2 concentration (eCO2) has the potential to increase vegetation carbon storage if increased net primary production causes increased long-lived biomass. Model predictions of eCO2 effects on vegetation carbon storage depend on how allocation and turnover processes are represented. * We used data from two temperate forest free-air CO2 enrichment (FACE) experiments to evaluate representations of allocation and turnover in 11 ecosystem models. * Observed eCO2 effects on allocation were dynamic. Allocation schemes based on functional relationships among biomass fractions that vary with resource availability were best able to capture the general features of the observations. Allocation schemes based on constant fractions or resource limitations performed less well, with some models having unintended outcomes. Few models represent turnover processes mechanistically and there was wide variation in predictions of tissue lifespan. Consequently, models did not perform well at predicting eCO2 effects on vegetation carbon storage. * Our recommendations to reduce uncertainty include: use of allocation schemes constrained by biomass fractions; careful testing of allocation schemes; and synthesis of allocation and turnover data in terms of model parameters. Data from intensively studied ecosystem manipulation experiments are invaluable for constraining models and we recommend that such experiments should attempt to fully quantify carbon, water and nutrient budgets.},
author = {{De Kauwe}, Martin G and Medlyn, Belinda E and Zaehle, S{\"{o}}nke and Walker, Anthony P and Dietze, Michael C and Wang, Ying-Ping and Luo, Yiqi and Jain, Atul K and El-Masri, Bassil and Hickler, Thomas and W{\aa}rlind, David and Weng, Ensheng and Parton, William J and Thornton, Peter E and Wang, Shusen and Prentice, I Colin and Asao, Shinichi and Smith, Benjamin and McCarthy, Heather R and Iversen, Colleen M and Hanson, Paul J and Warren, Jeffrey M and Oren, Ram and Norby, Richard J},
doi = {10.1111/nph.12847},
isbn = {1469-8137},
issn = {0028646X},
journal = {New Phytologist},
keywords = {CO2 fertil,allocation,carbon (C),climate change},
month = {aug},
number = {3},
pages = {883--899},
title = {{Where does the carbon go? A model-data intercomparison of vegetation carbon allocation and turnover processes at two temperate forest free-air CO2 enrichment sites}},
url = {http://dx.doi.org/10.1111/nph.12847 http://doi.wiley.com/10.1111/nph.12847},
volume = {203},
year = {2014}
}
@article{DeKauwe2013,
author = {{De Kauwe}, Martin G. and Medlyn, Belinda E. and Zaehle, S{\"{o}}nke and Walker, Anthony P. and Dietze, Michael C. and Hickler, Thomas and Jain, Atul K. and Luo, Yiqi and Parton, William J. and Prentice, I. Colin and Smith, Benjamin and Thornton, Peter E. and Wang, Shusen and Wang, Ying-Ping and W{\aa}rlind, David and Weng, Ensheng and Crous, Kristine Y. and Ellsworth, David S. and Hanson, Paul J. and {Seok Kim}, Hyun- and Warren, Jeffrey M. and Oren, Ram and Norby, Richard J.},
doi = {10.1111/gcb.12164},
issn = {13541013},
journal = {Global Change Biology},
month = {jun},
number = {6},
pages = {1759--1779},
title = {{Forest water use and water use efficiency at elevated CO2: a model-data intercomparison at two contrasting temperate forest FACE sites}},
url = {http://doi.wiley.com/10.1111/gcb.12164},
volume = {19},
year = {2013}
}
@article{DelaVega2020,
author = {de la Vega, Elwyn and Chalk, Thomas B. and Wilson, Paul A. and Bysani, Ratna Priya and Foster, Gavin L.},
doi = {10.1038/s41598-020-67154-8},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {11002},
title = {{Atmospheric CO2 during the Mid-Piacenzian Warm Period and the M2 glaciation}},
url = {http://www.nature.com/articles/s41598-020-67154-8},
volume = {10},
year = {2020}
}
@article{DeOliveiraGarcia2020,
author = {{de Oliveira Garcia}, W and Amann, T and Hartmann, J and Karstens, K and Popp, A and Boysen, L R and Smith, P and Goll, D},
doi = {10.5194/bg-17-2107-2020},
journal = {Biogeosciences},
number = {7},
pages = {2107--2133},
title = {{Impacts of enhanced weathering on biomass production for negative emission technologies and soil hydrology}},
volume = {17},
year = {2020}
}
@article{DERICHTER201768,
abstract = {Large-scale atmospheric removal of greenhouse gases (GHGs) including methane, nitrous oxide and ozone-depleting halocarbons could reduce global warming more quickly than atmospheric removal of CO2. Photocatalysis of methane oxidizes it to CO2, effectively reducing its global warming potential (GWP) by at least 90{\%}. Nitrous oxide can be reduced to nitrogen and oxygen by photocatalysis; meanwhile halocarbons can be mineralized by red-ox photocatalytic reactions to acid halides and CO2. Photocatalysis avoids the need for capture and sequestration of these atmospheric components. Here review an unusual hybrid device combining photocatalysis with carbon-free electricity with no-intermittency based on the solar updraft chimney. Then we review experimental evidence regarding photocatalytic transformations of non-CO2 GHGs. We propose to combine TiO2-photocatalysis with solar chimney power plants (SCPPs) to cleanse the atmosphere of non-CO2 GHGs. Worldwide installation of 50,000 SCPPs, each of capacity 200MW, would generate a cumulative 34PWh of renewable electricity by 2050, taking into account construction time. These SCPPs equipped with photocatalyst would process 1atmospheric volume each 14–16 years, reducing or stopping the atmospheric growth rate of the non-CO2 GHGs and progressively reducing their atmospheric concentrations. Removal of methane, as compared to other GHGs, has enhanced efficacy in reducing radiative forcing because it liberates more °OH radicals to accelerate the cleaning of the troposphere. The overall reduction in non-CO2 GHG concentration would help to limit global temperature rise. By physically linking greenhouse gas removal to renewable electricity generation, the hybrid concept would avoid the moral hazard associated with most other climate engineering proposals.},
author = {de Richter, Renaud and Ming, Tingzhen and Davies, Philip and Liu, Wei and Caillol, Sylvain},
doi = {10.1016/j.pecs.2017.01.001},
issn = {03601285},
journal = {Progress in Energy and Combustion Science},
keywords = {Atmospheric greenhouse gas removal,GHG photocatalysis,Giant photocatalytic reactor,Large scale atmospheric air cleansing,Negative emissions technology,Solar chimney power plant,Solar-wind hybrid},
month = {may},
pages = {68--96},
title = {{Removal of non-CO2 greenhouse gases by large-scale atmospheric solar photocatalysis}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0360128516300569},
volume = {60},
year = {2017}
}
@article{DeVries2009,
abstract = {In this study, we present estimated ranges in carbon (C) sequestration per kg nitrogen (N) addition in above-ground biomass and in soil organic matter for forests and heathlands, based on: (i) empirical relations between spatial patterns of carbon uptake and influencing environmental factors including nitrogen deposition (forests only), (ii)15N field experiments, (iii) long-term low-dose N fertilizer experiments and (iv) results from ecosystem models. The results of the various studies are in close agreement and show that above-ground accumulation of carbon in forests is generally within the range 15-40 kg C/kg N. For heathlands, a range of 5-15 kg C/kg N has been observed based on low-dose N fertilizer experiments. The uncertainty in C sequestration per kg N addition in soils is larger than for above-ground biomass and varies on average between 5 and 35 kg C/kg N for both forests and heathlands. All together these data indicate a total carbon sequestration range of 5-75 kg C/kg N deposition for forest and heathlands, with a most common range of 20-40 kg C/kg N. Results cannot be extrapolated to systems with very high N inputs, nor to other ecosystems, such as peatlands, where the impact of N is much more variable, and may range from C sequestration to C losses. {\textcopyright} 2009 Elsevier B.V. All rights reserved.},
archivePrefix = {arXiv},
arxivId = {arXiv:1011.1669v3},
author = {de Vries, W. and Solberg, S. and Dobbertin, M. and Sterba, H. and Laubhann, D. and van Oijen, M. and Evans, C. and Gundersen, P. and Kros, J. and Wamelink, G.W.W. and Reinds, G.J. and Sutton, M.A.},
doi = {10.1016/j.foreco.2009.02.034},
eprint = {arXiv:1011.1669v3},
isbn = {0378-1127},
issn = {03781127},
journal = {Forest Ecology and Management},
keywords = {C/N ratios,Carbon sequestration,Deposition,Ecosystem production,Environmental change,Fertilizer experiments,Forests,Heathlands,Nitrogen},
month = {sep},
number = {8},
pages = {1814--1823},
pmid = {17151199},
title = {{The impact of nitrogen deposition on carbon sequestration by European forests and heathlands}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0378112709001479},
volume = {258},
year = {2009}
}
@article{Dean2018,
abstract = {Methane (CH4) is produced in many natural systems that are vulnerable to change under a warming climate, yet current CH4 budgets, as well as future shifts in CH4 emissions, have high uncertainties. Climate change has the potential to increase CH4 emissions from critical systems such as wetlands, marine and freshwater systems, permafrost, and methane hydrates, through shifts in temperature, hydrology, vegetation, landscape disturbance and sea level rise. Increased CH4 emissions from these systems would in turn induce further climate change, resulting in a positive climate feedback. Here we synthesize biological, geochemical and physically focused CH4 climate feedback literature, bringing together the key findings of these disciplines. We discuss environment-specific feedback processes, including the microbial, physical and geochemical inter-linkages and the timescales on which they operate, and present the current state of knowledge of CH4 climate feedbacks in the immediate and distant future. The important linkages between microbial activity and climate warming are discussed with the aim to better constrain the sensitivity of the CH4 cycle to future climate predictions. We determine that wetlands will form the majority of the CH4 climate feedback up to 2100. Beyond this timescale, CH4 emissions from marine and freshwater systems and permafrost environments could become more important. Significant CH4 emissions to the atmosphere from the dissociation of methane hydrates are not expected in the near future. Our key findings highlight the importance of quantifying whether CH4 consumption can counter balance CH4 production under future climate scenarios.},
author = {Dean, Joshua F. and Middelburg, Jack J. and R{\"{o}}ckmann, Thomas and Aerts, Rien and Blauw, Luke G. and Egger, Matthias and Jetten, Mike S. M. and de Jong, Anniek E. E. and Meisel, Ove H. and Rasigraf, Olivia and Slomp, Caroline P. and in't Zandt, Michiel H. and Dolman, A. J.},
doi = {10.1002/2017RG000559},
isbn = {8755-1209},
issn = {87551209},
journal = {Reviews of Geophysics},
keywords = {climate change,marine and freshwaters,methane (CH4),methane hydrates,permafrost,wetlands},
month = {mar},
number = {1},
pages = {207--250},
pmid = {3196358},
title = {{Methane feedbacks to the global climate system in a warmer world}},
url = {http://doi.wiley.com/10.1002/2017RG000559},
volume = {56},
year = {2018}
}
@article{DeConto2008,
author = {DeConto, Robert M. and Pollard, David and Wilson, Paul A. and P{\"{a}}like, Heiko and Lear, Caroline H. and Pagani, Mark},
doi = {10.1038/nature07337},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7213},
pages = {652--656},
title = {{Thresholds for Cenozoic bipolar glaciation}},
url = {http://www.nature.com/doifinder/10.1038/nature07337},
volume = {455},
year = {2008}
}
@article{Deemer2016,
author = {Deemer, Bridget R. and Harrison, John A. and Li, Siyue and Beaulieu, Jake J. and DelSontro, Tonya and Barros, Nathan and Bezerra-Neto, Jos{\'{e}} F. and Powers, Stephen M. and dos Santos, Marco A. and Vonk, J. Arie},
doi = {10.1093/biosci/biw117},
issn = {0006-3568},
journal = {BioScience},
month = {nov},
number = {11},
pages = {949--964},
title = {{Greenhouse Gas Emissions from Reservoir Water Surfaces: A New Global Synthesis}},
url = {https://academic.oup.com/bioscience/article/66/11/949/2754271},
volume = {66},
year = {2016}
}
@article{DelSontro2018,
author = {DelSontro, Tonya and Beaulieu, Jake J. and Downing, John A.},
doi = {10.1002/lol2.10073},
issn = {23782242},
journal = {Limnology and Oceanography Letters},
month = {jun},
number = {3},
pages = {64--75},
title = {{Greenhouse gas emissions from lakes and impoundments: Upscaling in the face of global change}},
url = {http://doi.wiley.com/10.1002/lol2.10073},
volume = {3},
year = {2018}
}
@article{Denisov2013,
abstract = {Carried out are numerical experiments with the IAP RAS global climate model (IAP RAS CM) under new RCP scenarios of anthropogenic impact for the 18th-21st centuries taking account of the response of the methane emission from the soil to the atmosphere and effects of chemical processes in the atmosphere on the climate changes. The model generally simulates the preindustrial and present-day characteristics of the methane cycle. Methane emissions from the soil to the atmosphere (within the range of 150-160 Mt CH4/year for the present-day period) reach 170-230 Mt CH4/year by the late 21st century depending on the scenario of anthropogenic impact. The methane concentration under the most aggressive RCP 8.5 anthropogenic scenario increases up to 3900 ppb by the late 21st century. Under more moderate RCP 4.5 and 6.0 anthropogenic scenarios, it reaches 1850-1980 ppb in the second half of the 21st century and decreases afterwards. Under RCP 2.6 scenario, the methane concentration maximum of 1730 ppb in the atmosphere is reached in the second decade of the 21st century. The taking account of the interaction between the processes in the soils and the climate leads to the additional increase in the methane content in the atmosphere by 10-25{\%} in the 21st century depending on the scenario of anthropogenic impact. The taking account of the methane oxidation in the atmosphere in the case of warming reduces the increase in its concentration by 5-40{\%}. The associated changes in the surface air temperature turn out to be small (less than 0.1 K globally or 4{\%} of the warming expected by the late 21st century). {\textcopyright} 2013 Allerton Press, Inc.},
author = {Denisov, S. N. and Eliseev, A. V. and Mokhov, I. I.},
doi = {10.3103/S1068373913110034},
issn = {1068-3739},
journal = {Russian Meteorology and Hydrology},
month = {nov},
number = {11},
pages = {741--749},
title = {{Climate change in IAP RAS global model taking account of interaction with methane cycle under anthropogenic scenarios of RCP family}},
url = {http://link.springer.com/10.3103/S1068373913110034},
volume = {38},
year = {2013}
}
@article{Denisov2019,
abstract = {Estimates of the contribution of anthropogenic and natural greenhouse gases to the atmosphere from the territory of Russia to global climate change under different scenarios of anthropogenic emissions in the 21st century are obtained. It is shown that the consideration of the changes in climate conditions can strongly affect the indicators of impacts of different greenhouse gas emissions on the climate system, especially over long time horizons. In making decisions, it is necessary to take into account that, with respect to the planning horizon, the role of natural flows of greenhouse gases into the atmosphere from the terrestrial ecosystems can change. Currently, in the Russian regions, CO2 uptake by terrestrial ecosystems decelerate global warming, and their CH4 release into the atmosphere accelerate it. In this case, the general effect of natural fluxes of these greenhouse gases from the Russian regions under modern conditions foster deceleration of warming. The role of this effect decelerating warming will grow in the first half of the 21st century, and after reaching the maximum, which depends on the scenario of anthropogenic emissions, it will decrease by the end of the century under all scenarios of anthropogenic impacts considered due to the growth of natural emissions of CH4 and a decrease in the absorption of CO2 by the terrestrial ecosystems.},
author = {Denisov, S N and Eliseev, A V and Mokhov, I I},
doi = {10.1134/S1028334X19090010},
issn = {1531-8354},
journal = {Doklady Earth Sciences},
number = {1},
pages = {1066--1071},
title = {{Contribution of Natural and Anthropogenic Emissions of CO2 and CH4 to the Atmosphere from the Territory of Russia to Global Climate Changes in the Twenty-first Century}},
url = {https://doi.org/10.1134/S1028334X19090010},
volume = {488},
year = {2019}
}
@incollection{Denman2007,
address = {Cambridge, United Kingdom and New York, NY, USA},
author = {Denman, Kenneth L and Brasseur, Guy P and Chidthaisong, Amnat and Ciais, Philippe and Cox, Peter M and Dickinson, Robert E and Hauglustaine, Didier A and Heinze, Christoph and Holland, Elisabeth A and Jacob, Daniel J and Lohmann, Ulrike and Ramachandran, Srikanthan and {da Silva Dias}, Pedro and Wofsy, Steven C and Zhang, XiaoYe and Steffen, Will},
booktitle = {Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change},
editor = {Solomon, S and Qin, D and Manning, M and Chen, Z and Marquis, M and Averyt, K B and Tignor, M and Miller, H L},
isbn = {9780521880091},
pages = {499--588},
publisher = {Cambridge University Press},
title = {{Couplings Between Changes in the Climate System and Biogeochemistry}},
url = {https://www.ipcc.ch/report/ar4/wg1},
year = {2007}
}
@article{Denvil-Sommer2018,
author = {Denvil-Sommer, Anna and Gehlen, Marion and Vrac, Mathieu and Mejia, Carlos},
doi = {10.5194/gmd-12-2091-2019},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {may},
number = {5},
pages = {2091--2105},
title = {{LSCE-FFNN-v1: a two-step neural network model for the reconstruction of surface ocean pCO2 over the global ocean}},
url = {https://www.geosci-model-dev.net/12/2091/2019/},
volume = {12},
year = {2019}
}
@article{Deutsch2014,
abstract = {Climate warming is expected to reduce oxygen (O2) supply to the ocean and expand its oxygen minimum zones (OMZs). We reconstructed variations in the extent of North Pacific anoxia since 1850 using a geochemical proxy for denitrification ($\delta$15N) from multiple sediment cores. Increasing $\delta$15N since {\~{}}1990 records an expansion of anoxia, consistent with observed O2 trends. However, this was preceded by a longer declining $\delta$15N trend that implies that the anoxic zone was shrinking for most of the 20th century. Both periods can be explained by changes in winds over the tropical Pacific that drive upwelling, biological productivity, and O2 demand within the OMZ. If equatorial Pacific winds resume their predicted weakening trend, the oceans largest anoxic zone will contract despite a global O2 decline.},
author = {Deutsch, Curtis and Berelson, William and Thunell, Robert and Weber, Thomas and Tems, Caitlin and McManus, James and Crusius, John and Ito, Taka and Baumgartner, Timothy and Ferreira, Vicente and Mey, Jacob and van Geen, Alexander},
doi = {10.1126/science.1252332},
issn = {0036-8075},
journal = {Science},
number = {6197},
pages = {665--668},
publisher = {American Association for the Advancement of Science},
title = {{Centennial changes in North Pacific anoxia linked to tropical trade winds}},
url = {http://science.sciencemag.org/content/345/6197/665},
volume = {345},
year = {2014}
}
@article{Deutsch2011,
abstract = {Oxygen (O2) is a critical constraint on marine ecosystems. As oceanic O2 falls to hypoxic concentrations, habitability for aerobic organisms decreases rapidly. We show that the spatial extent of hypoxia is highly sensitive to small changes in the oceans O2 content, with maximum responses at suboxic concentrations where anaerobic metabolisms predominate. In model-based reconstructions of historical oxygen changes, the worlds largest suboxic zone, in the Pacific Ocean, varies in size by a factor of 2. This is attributable to climate-driven changes in the depth of the tropical and subtropical thermocline that have multiplicative effects on respiration rates in low-O2 water. The same mechanism yields even larger fluctuations in the rate of nitrogen removal by denitrification, creating a link between decadal climate oscillations and the nutrient limitation of marine photosynthesis.},
author = {Deutsch, Curtis and Brix, Holger and Ito, Taka and Frenzel, Hartmut and Thompson, LuAnne},
doi = {10.1126/science.1202422},
issn = {0036-8075},
journal = {Science},
number = {6040},
pages = {336--339},
publisher = {American Association for the Advancement of Science},
title = {{Climate-Forced Variability of Ocean Hypoxia}},
url = {https://science.sciencemag.org/content/333/6040/336},
volume = {333},
year = {2011}
}
@article{Devaraju2016,
abstract = {In this paper, using the fully coupled NCAR Community Earth System Model (CESM1.0.4), we investigate the relative importance of CO2-fertilization, climate warming, anthropogenic nitrogen deposition, and land use and land cover change (LULCC) for terrestrial carbon uptake during the historical period (1850–2005). In our simulations, between the beginning and end of this period, we find an increase in global net primary productivity (NPP) on land of about 4 PgCyr−1 (8.2 {\%}) with a contribution of 2.3 PgCyr−1 from CO2-fertilization and 2.0 PgCyr−1 from nitrogen deposition. Climate warming also causes NPP to increase by 0.35 PgCyr−1 but LULCC causes a decline of 0.7 PgCyr−1. These results indicate that the recent increase in vegetation productivity is most likely driven by CO2 fertilization and nitrogen deposition. Further, we find that this configuration of CESM projects that the global terrestrial ecosystem has been a net source of carbon during 1850–2005 (release of 45.1 ± 2.4 PgC), largely driven by historical LULCC related CO2 fluxes to the atmosphere. During the recent three decades (early 1970s to early 2000s), however, our model simulations project that the terrestrial ecosystem acts as a sink, taking up about 10 PgC mainly due to CO2 fertilization and nitrogen deposition. Our results are in good qualitative agreement with recent studies that indicate an increase in vegetation production and water use efficiency in the satellite era and that the terrestrial ecosystem has been a net sink for carbon in recent decades.},
author = {Devaraju, N. and Bala, G. and Caldeira, K. and Nemani, R.},
doi = {10.1007/s00382-015-2830-8},
issn = {0930-7575},
journal = {Climate Dynamics},
keywords = {CO2 fertilization,Climate change,Land use land cover change,Net primary productivity,Nitrogen deposition,Terrestrial carbon uptake},
month = {jul},
number = {1-2},
pages = {173--190},
title = {{A model based investigation of the relative importance of CO2-fertilization, climate warming, nitrogen deposition and land use change on the global terrestrial carbon uptake in the historical period}},
url = {http://link.springer.com/10.1007/s00382-015-2830-8},
volume = {47},
year = {2016}
}
@article{DeVries2014,
abstract = {AbstractThis study presents a new estimate of the oceanic anthropogenic CO2(Cant) sink over the industrial era (1780 to present), from assimilation of potential temperature, salinity, radiocarbon, and CFC-11 observations in a global steady state ocean circulation inverse model (OCIM). This study differs from previous data-based estimates of the oceanic Cant sink in that dynamical constraints on ocean circulation are accounted for, and the ocean circulation is explicitly modeled, allowing the calculation of oceanic Cant storage, air-sea fluxes, and transports in a consistent manner. The resulting uncertainty of the OCIM-estimated Cant uptake, transport, and storage is significantly smaller than the comparable uncertainty from purely data-based or model-based estimates. The OCIM-estimated oceanic Cant storage is 160?166 PgC in 2012, and the oceanic Cant uptake rate averaged over the period 2000?2010 is 2.6 PgC yr?1 or about 30{\%} of current anthropogenic CO2 emissions. This result implies a residual (primarily terrestrial) Cant sink of about 1.6 PgC yr?1 for the same period. The Southern Ocean is the primary conduit for Cant entering the ocean, taking up about 1.1 PgC yr?1 in 2012, which represents about 40{\%} of the contemporary oceanic Cant uptake. It is suggested that the most significant source of remaining uncertainty in the oceanic Cant sink is due to potential variability in the ocean circulation over the industrial era.},
annote = {doi: 10.1002/2013GB004739},
author = {DeVries, Tim},
doi = {10.1002/2013GB004739},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {anthropogenic carbon,carbon cycle,data assimilation,ocean circulation},
month = {jul},
number = {7},
pages = {631--647},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{The oceanic anthropogenic CO2 sink: Storage, air-sea fluxes, and transports over the industrial era}},
url = {https://doi.org/10.1002/2013GB004739 http://doi.wiley.com/10.1002/2013GB004739},
volume = {28},
year = {2014}
}
@article{DeVries2019a,
abstract = {Measurements show large decadal variability in the rate of C O 2 accumulation in the atmosphere that is not driven by C O 2 emissions. The decade of the 1990s experienced enhanced carbon accumulation in the atmosphere relative to emissions, while in the 2000s, the atmospheric growth rate slowed, even though emissions grew rapidly. These variations are driven by natural sources and sinks of C O 2 due to the ocean and the terrestrial biosphere. In this study, we compare three independent methods for estimating oceanic C O 2 uptake and find that the ocean carbon sink could be responsible for up to 40{\%} of the observed decadal variability in atmospheric C O 2 accumulation. Data-based estimates of the ocean carbon sink from p C O 2 mapping methods and decadal ocean inverse models generally agree on the magnitude and sign of decadal variability in the ocean C O 2 sink at both global and regional scales. Simulations with ocean biogeochemical models confirm that climate variability drove the observed decadal trends in ocean C O 2 uptake, but also demonstrate that the sensitivity of ocean C O 2 uptake to climate variability may be too weak in models. Furthermore, all estimates point toward coherent decadal variability in the oceanic and terrestrial C O 2 sinks, and this variability is not well-matched by current global vegetation models. Reconciling these differences will help to constrain the sensitivity of oceanic and terrestrial C O 2 uptake to climate variability and lead to improved climate projections and decadal climate predictions.},
author = {DeVries, Tim and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Andrews, Oliver and Berthet, Sarah and Hauck, Judith and Ilyina, Tatiana and Landsch{\"{u}}tzer, Peter and Lenton, Andrew and Lima, Ivan D. and Nowicki, Michael and Schwinger, J{\"{o}}rg and S{\'{e}}f{\'{e}}rian, Roland},
doi = {10.1073/pnas.1900371116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Carbon budget,Carbon dioxide,Climate,Ocean carbon sink,Terrestrial carbon sink,Variability},
month = {may},
number = {24},
pages = {201900371},
publisher = {National Academy of Sciences},
title = {{Decadal trends in the ocean carbon sink}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1900371116 http://www.pnas.org/content/116/24/11646.abstract},
volume = {116},
year = {2019}
}
@article{DeVries2017,
abstract = {Recent increase in oceanic carbon uptake driven by weaker upper-ocean overturning Tim DeVries, Mark Holzer {\&} Francois Primeau Nature volume 542, pages 215–218 (09 February 2017) | Download Citation Abstract The ocean is the largest sink for anthropogenic carbon dioxide (CO2), having absorbed roughly 40 per cent of CO2 emissions since the beginning of the industrial era1,2. Recent data show that oceanic CO2 uptake rates have been growing over the past decade3,4,5,6,7, reversing a trend of stagnant or declining carbon uptake during the 1990s8,9,10,11,12,13,14. Here we show that ocean circulation variability is the primary driver of these changes in oceanic CO2 uptake over the past several decades. We use a global inverse model to quantify the mean ocean circulation during the 1980s, 1990s and 2000s, and then estimate the impact of decadal circulation changes on the oceanic CO2 sink using a carbon cycling model. We find that during the 1990s an enhanced upper-ocean overturning circulation drove increased outgassing of natural CO2, thus weakening the global CO2 sink. This trend reversed during the 2000s as the overturning circulation weakened. Continued weakening of the upper-ocean overturning is likely to strengthen the CO2 sink in the near future by trapping natural CO2 in the deep ocean, but ultimately may limit oceanic uptake of anthropogenic CO2.},
author = {DeVries, Tim and Holzer, Mark and Primeau, Francois},
doi = {10.1038/nature21068},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7640},
pages = {215--218},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Recent increase in oceanic carbon uptake driven by weaker upper-ocean overturning}},
url = {http://www.nature.com/articles/nature21068 http://www.nature.com/doifinder/10.1038/nature21068 http://dx.doi.org/10.1038/nature21068},
volume = {542},
year = {2017}
}
@article{Dickson2012,
abstract = {Uncertainty over the trajectory of seawater oxygenation in the coming decades is of particular concern in the light of geological episodes of abrupt global warming that were frequently accompanied by lowered seawater oxygen concentrations. Here we present an assessment of global seawater oxygenation from an interval of one of these warming episodes, the Paleocene-Eocene Thermal Maximum (PETM, 55.9 m.y. ago). Our results, obtained from Integrated Ocean Drilling Program Expedition 302 Site M0004 in the Arctic Ocean, are based on molybdenum isotope determinations and molybdenum, rhenium, and uranium abundances. These data indicate a small global expansion of low-oxygen marine environments in the upper part of the PETM interval compared with the present day. More extensive seawater deoxygenation may have occurred for as long as ∼100 k.y., associated with a high rate of global warming and carbon oxidation at the start of the PETM. Our data also reveal molybdenum isotope compositions in Arctic Ocean deposits that are outside the range currently documented in marine environments. These exceptional compositions could reflect either the influence of hydrothermal inputs or equilibrium isotope fractionations associated with molybdenum sulfide speciation.},
author = {Dickson, Alexander J. and Cohen, Anthony S. and Coe, Angela L.},
doi = {10.1130/G32977.1},
isbn = {0091-7613},
issn = {0091-7613},
journal = {Geology},
month = {jul},
number = {7},
pages = {639--642},
title = {{Seawater oxygenation during the Paleocene–Eocene Thermal Maximum}},
url = {https://pubs.geoscienceworld.org/geology/article/40/7/639-642/130940},
volume = {40},
year = {2012}
}
@article{Dickson2014,
abstract = {Records of the paleoenvironmental changes that occurred during the Paleocene-Eocene Thermal Maximum (PETM) are preserved in sedimentary rocks along the margins of the former Tethys Ocean and Peri-Tethys. This paper presents new geochemical data that constrain paleoproductivity, sediment delivery, and seawater redox conditions, from three sites that were located in the Peri-Tethys region. Trace and major element, iron speciation, and biomarker data indicate that water column anoxia was established during episodes when inputs of land-derived higher plant organic carbon and highly weathered detrital clays and silts became relatively higher. Anoxic conditions are likely to have been initially caused by two primary processes: (i) oxygen consumption by high rates of marine productivity, initially stimulated by the rapid delivery of terrestrially derived organic matter and nutrients, and (ii) phosphorus regeneration from seafloor sediments. The role of the latter process requires further investigation before its influence on the spread of deoxygenated seawater during the PETM can be properly discerned. Other oxygen-forcing processes, such as temperature/salinity-driven water column stratification and/or methane oxidation, are considered to have been relatively less important in the study region. Organic carbon enrichments occur only during the initial stages of the PETM as defined by the negative carbon isotope excursions at each site. The lack of observed terminal stage organic carbon enrichment does not support a link between PETM climate recovery and the sequestration of excess atmospheric CO2 as organic carbon in this region; such a feedback may, however, have been important in the early stages of the PETM. {\textcopyright}2014. American Geophysical Union. All Rights Reserved.},
author = {Dickson, Alexander J. and Rees-Owen, Rhian L. and M{\"{a}}rz, Christian and Coe, Angela L. and Cohen, Anthony S. and Pancost, Richard D. and Taylor, Kyle and Shcherbinina, Ekaterina},
doi = {10.1002/2014PA002629},
issn = {19449186},
journal = {Paleoceanography},
keywords = {PETM,Tethys,biomarkers,carbon burial,redox,trace elements},
number = {6},
pages = {471--488},
title = {{The spread of marine anoxia on the northern Tethys margin during the Paleocene–Eocene Thermal Maximum}},
volume = {29},
year = {2014}
}
@article{Dignac2017a,
abstract = {The international 4 per 1000 initiative aims at supporting states and non-governmental stakeholders in their efforts towards a better management of soil carbon (C) stocks. These stocks depend on soil C inputs and outputs. They are the result of fine spatial scale interconnected mechanisms, which stabilise/destabilise organic matter-borne C. Since 2016, the CarboSMS consortium federates French researchers working on these mechanisms and their effects on C stocks in a local and global change setting (land use, agricultural practices, climatic and soil conditions, etc.). This article is a synthesis of this consortium's first seminar. In the first part, we present recent advances in the understanding of soil C stabilisation mechanisms comprising biotic and abiotic processes, which occur concomitantly and interact. Soil organic C stocks are altered by biotic activities of plants (the main source of C through litter and root systems), microorganisms (fungi and bacteria) and ‘ecosystem engineers' (earthworms, termites, ants). In the meantime, abiotic processes related to the soil-physical structure, porosity and mineral fraction also modify these stocks. In the second part, we show how agricultural practices affect soil C stocks. By acting on both biotic and abiotic mechanisms, land use and management practices (choice of plant species and density, plant residue exports, amendments, fertilisation, tillage, etc.) drive soil spatiotemporal organic inputs and organic matter sensitivity to mineralisation. Interaction between the different mechanisms and their effects on C stocks are revealed by meta-analyses and long-term field studies. The third part addresses upscaling issues. This is a cause for major concern since soil organic C stabilisation mechanisms are most often studied at fine spatial scales (mm–$\mu$m) under controlled conditions, while agricultural practices are implemented at the plot scale. We discuss some proxies and models describing specific mechanisms and their action in different soil and climatic contexts and show how they should be taken into account in large scale models, to improve change predictions in soil C stocks. Finally, this literature review highlights some future research prospects geared towards preserving or even increasing C stocks, our focus being put on the mechanisms, the effects of agricultural practices on them and C stock prediction models.},
author = {Dignac, Marie France and Derrien, Delphine and Barr{\'{e}}, Pierre and Barot, S{\'{e}}bastien and C{\'{e}}cillon, Lauric and Chenu, Claire and Chevallier, Tiphaine and Freschet, Gr{\'{e}}goire T. and Garnier, Patricia and Guenet, Bertrand and Hedde, Micka{\"{e}}l and Klumpp, Katja and Lashermes, Gwena{\"{e}}lle and Maron, Pierre Alain and Nunan, Naoise and Roumet, Catherine and Basile-Doelsch, Isabelle},
doi = {10.1007/s13593-017-0421-2},
issn = {17730155},
journal = {Agronomy for Sustainable Development},
pages = {14},
title = {{Increasing soil carbon storage: mechanisms, effects of agricultural practices and proxies. A review}},
volume = {37},
year = {2017}
}
@article{Dixon2014,
abstract = {This paper reviews the recent regulatory developments relating to transboundary carbon dioxide capture and storage (CCS) activities and regulation of ocean fertilization and other marine geoengineering activities arising from the work and agreements under the London Protocol from 2010 to 2013. Geological storage of CO2 in transboundary sub-seabed geological formations is now possible and regulated under the London Protocol, but not yet the export of CO2 for geological storage in sub-seabed geological formation until an export amendment is ratified by two-thirds of the Parties to the London Protocol and comes into force. With marine geoengineering based upon placement of matter in the marine environment, the London Protocol has decided that such activities fall under its scope. It has considered and prohibited ocean fertilization except for research purposes only, and a procedure is provided for new marine geoengineering activities to be considered. For both activities, detailed guidance is provided on the assessments and conditions for issuing of permits.},
author = {Dixon, Tim and Garrett, Justine and Kleverlaan, Edward},
doi = {10.1016/j.egypro.2014.11.698},
issn = {18766102},
journal = {Energy Procedia},
keywords = {CO2 geological storage,Environmental protection,Geoengineering,Legal,Marine environment,Ocean fertilization,Regulation,Transboundary},
month = {jan},
pages = {6623--6628},
publisher = {Elsevier},
title = {{Update on the London Protocol – Developments on Transboundary CCS and on Geoengineering}},
url = {https://www.sciencedirect.com/science/article/pii/S1876610214025132?via{\%}3Dihub https://linkinghub.elsevier.com/retrieve/pii/S1876610214025132},
volume = {63},
year = {2014}
}
@article{Djakovac2015,
abstract = {Hypoxia events frequently occurred in the bottom layer of the northern Adriatic Sea (NAd) from mid-summer to mid-autumn, when the water column is highly stratified, with highly variable spatial extent and duration. To determine the mechanisms of changes in hypoxia frequency and their relation to environmental conditions, 40yr-long time series of dissolved oxygen and of parameters that describe freshwater influence, stratification processes, and circulation patterns were analysed. It was shown that seasonal hypoxic events in the open water areas coincided with the formation of cyclonic or anticyclonic circulation cells, whose stability was estimated by the appearance of the Istrian Coastal Counter Current (ICCC). The oxygenation of bottom waters during the period August–November of the last two decades has increased, whereas a decreasing trend was observed in surface waters. The frequency of hypoxic events at a larger scale in the NAd decreased since 1992, concurrently with reduced ICCC occurrences. However, the frequency of events in the western area, which is under a direct influence of Po River discharges, did not change significantly, although their intensity recently were lower than during the 1970s and 1980s.},
author = {Djakovac, Tamara and Supi{\'{c}}, Nastjenjka and {Bernardi Aubry}, Fabrizio and Degobbis, Danilo and Giani, Michele},
doi = {10.1016/j.jmarsys.2014.08.001},
issn = {09247963},
journal = {Journal of Marine Systems},
month = {jan},
pages = {179--189},
publisher = {Elsevier},
title = {{Mechanisms of hypoxia frequency changes in the northern Adriatic Sea during the period 1972–2012}},
url = {https://www.sciencedirect.com/science/article/pii/S0924796314002012 https://linkinghub.elsevier.com/retrieve/pii/S0924796314002012},
volume = {141},
year = {2015}
}
@article{Dlugokencky2003,
abstract = {The globally‐averaged atmospheric methane abundance determined from an extensive network of surface air sampling sites was constant at ∼1751 ppb from 1999 through 2002. Assuming that the methane lifetime has been constant, this implies that during this 4‐year period the global methane budget has been at steady state. We also observed a significant decrease in the difference between northern and southern polar zonal annual averages of CH4 from 1991 to 1992. Using a 3‐D transport model, we show that this change is consistent with a decrease in CH4 emissions of ∼10 Tg CH4 from north of 50°N in the early‐1990s. This decrease in emissions may have accelerated the global methane budget towards steady state. Based on current knowledge of the global methane budget and how it has changed with time, it is not possible to tell if the atmospheric methane burden has peaked, or if we are only observing a persistent, but temporary pause in its increase.},
author = {Dlugokencky, E. J. and Houwelling, S. and Bruhwiler, L. and Masarie, K.A. and Lang, P.M. and Miller, J.B. and Tans, P.P.},
doi = {10.1029/2003GL018126},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {oct},
number = {19},
pages = {1992},
publisher = {Wiley-Blackwell},
title = {{Atmospheric methane levels off: Temporary pause or a new steady-state?}},
url = {http://doi.wiley.com/10.1029/2003GL018126},
volume = {30},
year = {2003}
}
@article{Dlugokencky2011,
author = {Dlugokencky, Edward J. and Nisbet, Euan G. and Fisher, Rebecca and Lowry, David},
doi = {10.1098/rsta.2010.0341},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {may},
number = {1943},
pages = {2058--2072},
title = {{Global atmospheric methane: budget, changes and dangers}},
url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2010.0341},
volume = {369},
year = {2011}
}
@misc{Dlugokencky2019a,
author = {Dlugokencky, E.J. and Tans, P.:},
publisher = {National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA/ESRL)},
title = {{Trends in atmospheric carbon dioxide}},
url = {www.esrl.noaa.gov/gmd/ccgg/trends/global.html},
urldate = {2019-03-25},
year = {2019}
}
@article{Dlugokencky1994,
author = {Dlugokencky, E. J. and Masaire, K. A. and Lang, P. M. and Tans, P. P. and Steele, L. P. and Nisbet, E. G.},
doi = {10.1029/93GL03070},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {jan},
number = {1},
pages = {45--48},
title = {{A dramatic decrease in the growth rate of atmospheric methane in the northern hemisphere during 1992}},
url = {http://doi.wiley.com/10.1029/93GL03070},
volume = {21},
year = {1994}
}
@article{Don2012,
abstract = {Bioenergy from crops is expected to make a considerable contribution to climate change mitigation. However, bioenergy is not necessarily carbon neutral because emissions of CO2, N2O and CH4 during crop production may reduce or completely counterbalance CO2 savings of the substituted fossil fuels. These greenhouse gases (GHGs) need to be included into the carbon footprint calculation of different bioenergy crops under a range of soil conditions and management practices. This review compiles existing knowledge on agronomic and environmental constraints and GHG balances of the major European bioenergy crops, although it focuses on dedicated perennial crops such as Miscanthus and short rotation coppice species. Such second-generation crops account for only 3{\%} of the current European bioenergy production, but field data suggest they emit 40{\%} to {\textgreater}99{\%} less N2O than conventional annual crops. This is a result of lower fertilizer requirements as well as a higher N-use efficiency, due to effective N-recycling. Perennial energy crops have the potential to sequester additional carbon in soil biomass if established on former cropland (0.44 Mg soil C ha−1 yr−1 for poplar and willow and 0.66 Mg soil C ha−1 yr−1 for Miscanthus). However, there was no positive or even negative effects on the C balance if energy crops are established on former grassland. Increased bioenergy production may also result in direct and indirect land-use changes with potential high C losses when native vegetation is converted to annual crops. Although dedicated perennial energy crops have a high potential to improve the GHG balance of bioenergy production, several agronomic and economic constraints still have to be overcome.},
author = {Don, Axel and Osborne, Bruce and Hastings, Astley and Skiba, Ute and Carter, Mette S. and Drewer, Julia and Flessa, Heinz and Freibauer, Annette and Hyv{\"{o}}nen, Niina and Jones, Mike B. and Lanigan, Gary J. and Mander, {\"{U}}lo and Monti, Andrea and Djomo, Sylvestre Njakou and Valentine, John and Walter, Katja and Zegada-Lizarazu, Walter and Zenone, Terenzio},
doi = {10.1111/j.1757-1707.2011.01116.x},
issn = {17571693},
journal = {GCB Bioenergy},
language = {en},
month = {jul},
number = {4},
pages = {372--391},
title = {{Land-use change to bioenergy production in Europe: implications for the greenhouse gas balance and soil carbon}},
url = {http://doi.wiley.com/10.1111/j.1757-1707.2011.01116.x},
volume = {4},
year = {2012}
}
@article{Doney2009a,
abstract = {We quantify the mechanisms governing interannual variability in the global, upper-ocean inorganic carbon system using a hindcast simulation (1979–2004) of an ecosystem-biogeochemistry model forced with time-evolving atmospheric physics and dust deposition. We analyze the variability of three key, interrelated metrics—air–sea CO2 flux, surface-water carbon dioxide partial pressure pCO2, and upper-ocean dissolved inorganic carbon (DIC) inventory—presenting for each metric global spatial maps of the root mean square (rms) of anomalies from a model monthly climatology. The contribution of specific driving factors is diagnosed using Taylor expansions and linear regression analysis. The major regions of variability occur in the Southern Ocean, tropical Indo-Pacific, and Northern Hemisphere temperate and subpolar latitudes. Ocean circulation is the dominant factor driving variability over most of the ocean, modulating surface dissolved inorganic carbon that in turn alters surface-water pCO2 and air–sea CO2 flux variability (global integrated anomaly rms of 0.34PgCyr−1). Biological export and thermal solubility effects partially damp circulation-driven pCO2 variability in the tropics, while in the subtropics, thermal solubility contributes positively to surface-water pCO2 and air–sea CO2 flux variability. Gas transfer and net freshwater inputs induce variability in the air–sea CO2 flux in some specific regions. A component of air–sea CO2 flux variability (global integrated anomaly rms of 0.14PgCyr−1) arises from variations in biological export production induced by variations in atmospheric iron deposition downwind of dust source regions. Beginning in the mid-1990s, reduced global dust deposition generates increased air–sea CO2 outgassing in the Southern Ocean, consistent with trends derived from atmospheric CO2 inversions.},
author = {Doney, Scott C. and Lima, Ivan and Feely, Richard A. and Glover, David M. and Lindsay, Keith and Mahowald, Natalie and Moore, J. Keith and Wanninkhof, Rik},
doi = {10.1016/j.dsr2.2008.12.006},
issn = {09670645},
journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
month = {apr},
number = {8-10},
pages = {640--655},
publisher = {Pergamon},
title = {{Mechanisms governing interannual variability in upper-ocean inorganic carbon system and air–sea CO2 fluxes: Physical climate and atmospheric dust}},
url = {https://www.sciencedirect.com/science/article/pii/S096706450800427X?via{\%}3Dihub https://linkinghub.elsevier.com/retrieve/pii/S096706450800427X},
volume = {56},
year = {2009}
}
@article{Donis2017,
abstract = {Oxic lake surface waters are frequently oversaturated with methane (CH4). The contribution to the global CH4 cycle is significant, thus leading to an increasing number of studies and stimulating debates. Here we show, using a mass balance, on a temperate, mesotrophic lake, that {\~{}}90{\%} of CH4 emissions to the atmosphere is due to CH4 produced within the oxic surface mixed layer (SML) during the stratified period, while the often observed CH4 maximum at the thermocline represents only a physically driven accumulation. Negligible surface CH4 oxidation suggests that the produced 110 ± 60 nmol CH4 L−1 d−1 efficiently escapes to the atmosphere. Stable carbon isotope ratios indicate that CH4 in the SML is distinct from sedimentary CH4 production, suggesting alternative pathways and precursors. Our approach reveals CH4 production in the epilimnion that is currently overlooked, and that research on possible mechanisms behind the methane paradox should additionally focus on the lake surface layer.},
author = {Donis, D and Flury, S and St{\"{o}}ckli, A and Spangenberg, J E and Vachon, D and McGinnis, D F},
doi = {10.1038/s41467-017-01648-4},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {1661},
title = {{Full-scale evaluation of methane production under oxic conditions in a mesotrophic lake}},
url = {https://doi.org/10.1038/s41467-017-01648-4},
volume = {8},
year = {2017}
}
@article{Dore2009,
abstract = {Atmospheric carbon dioxide (CO2) is increasing at an accelerating rate, primarily due to fossil fuel combustion and land use change. A substantial fraction of anthropogenic CO2 emissions is absorbed by the oceans, resulting in a reduction of seawater pH. Continued acidification may over time have profound effects on marine biota and biogeochemical cycles. Although the physical and chemical basis for ocean acidification is well understood, there exist few field data of sufficient duration, resolution, and accuracy to document the acidification rate and to elucidate the factors governing its variability. Here we report the results of nearly 20 years of time-series measurements of seawater pH and associated parameters at Station ALOHA in the central North Pacific Ocean near Hawaii. We document a significant long-term decreasing trend of −0.0019 ± 0.0002 y−1 in surface pH, which is indistinguishable from the rate of acidification expected from equilibration with the atmosphere. Superimposed upon this trend is a strong seasonal pH cycle driven by temperature, mixing, and net photosynthetic CO2 assimilation. We also observe substantial interannual variability in surface pH, influenced by climate-induced fluctuations in upper ocean stability. Below the mixed layer, we find that the change in acidification is enhanced within distinct subsurface strata. These zones are influenced by remote water mass formation and intrusion, biological carbon remineralization, or both. We suggest that physical and biogeochemical processes alter the acidification rate with depth and time and must therefore be given due consideration when designing and interpreting ocean pH monitoring efforts and predictive models.},
author = {Dore, John E and Lukas, Roger and Sadler, Daniel W and Church, Matthew J and Karl, David M},
doi = {10.1073/pnas.0906044106},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {jul},
number = {30},
pages = {12235--12240},
pmid = {19666624},
publisher = {National Academy of Sciences},
title = {{Physical and biogeochemical modulation of ocean acidification in the central North Pacific}},
url = {https://www.pnas.org/content/106/30/12235},
volume = {106},
year = {2009}
}
@article{Drake2011,
abstract = {The earth's future climate state is highly dependent upon changes in terrestrial C storage in response to rising concentrations of atmospheric CO₂. Here we show that consistently enhanced rates of net primary production (NPP) are sustained by a C-cascade through the root-microbe-soil system; increases in the flux of C belowground under elevated CO₂ stimulated microbial activity, accelerated the rate of soil organic matter decomposition and stimulated tree uptake of N bound to this SOM. This process set into motion a positive feedback maintaining greater C gain under elevated CO₂ as a result of increases in canopy N content and higher photosynthetic N-use efficiency. The ecosystem-level consequence of the enhanced requirement for N and the exchange of plant C for N belowground is the dominance of C storage in tree biomass but the preclusion of a large C sink in the soil.},
author = {Drake, John E. and Gallet-Budynek, Anne and Hofmockel, Kirsten S. and Bernhardt, Emily S. and Billings, Sharon A. and Jackson, Robert B. and Johnsen, Kurt S. and Lichter, John and McCarthy, Heather R. and McCormack, M. Luke and Moore, David J. P. and Oren, Ram and Palmroth, Sari and Phillips, Richard P. and Pippen, Jeffrey S. and Pritchard, Seth G. and Treseder, Kathleen K. and Schlesinger, William H. and DeLucia, Evan H. and Finzi, Adrien C.},
doi = {10.1111/j.1461-0248.2011.01593.x},
isbn = {1461-0248 (Electronic)$\backslash$r1461-023X (Linking)},
issn = {1461023X},
journal = {Ecology Letters},
keywords = {Carbon sequestration,Coupled biogeochemical cycles,Coupled climate-carbon cycle models,Elevated CO2,Forest productivity,Nitrogen},
month = {apr},
number = {4},
pages = {349--357},
pmid = {21303437},
title = {{Increases in the flux of carbon belowground stimulate nitrogen uptake and sustain the long-term enhancement of forest productivity under elevated CO2}},
url = {http://doi.wiley.com/10.1111/j.1461-0248.2011.01593.x},
volume = {14},
year = {2011}
}
@article{Drake2018,
abstract = {The rate of CO2 diffusion from soils to the atmosphere (soil CO2 efflux, soil respiration; Rsoil) reflects the integrated activity of roots and microbes and is among the largest fluxes of the terrestrial global C cycle. Most experiments have demonstrated that Rsoil increases by 20?35{\%} following the exposure of an ecosystem to an atmosphere enriched in CO2 (i.e., eCO2), but such experiments have largely been performed in young and N-limited ecosystems. Here, we exposed a mature and phosphorus-limited eucalypt woodland to eCO2 and measured Rsoil across three full years with a combination of manual surveys and automated measurements. We also implemented an empirical model describing the dependence of Rsoil on volumetric soil water content (?) and soil temperature (Tsoil) to produce annual Rsoil flux estimates. Rsoil varied strongly with Tsoil, ?, and precipitation in complex and interacting ways. The realized long-term (weeks to years) temperature dependence (Q10) of Rsoil increased from {\~{}} 1.6 at low ? up to {\~{}} 3 at high ?. Additionally, Rsoil responded strongly and rapidly to precipitation events in a manner that depended on the conditions of ? and Tsoil at the beginning of the rain event; Rsoil increased by up to 300{\%} within 30?min when rain fell on dry soil that had not experience rain in the preceding week, but Rsoil was rapidly reduced by up to 70{\%} when rain fell on wet soil, leading to flooding. Repeated measures analysis of Rsoil observations over 3?years indicated no significant change in response to CO2 enrichment (P = 0.7), and elevated CO2 did not alter the dependence of Rsoil on Tsoil or ?. However, eCO2 increased Rsoil observations by {\~{}} 10{\%} under some constrained and moderate environmental conditions. Annual Rsoil flux sums estimated with an empirical model were {\~{}} 7{\%} higher in eCO2 plots than in aCO2 plots, but this difference was not statistically significant. The lack of a large eCO2 effect on Rsoil is consistent with recent evidence that aboveground net primary production was not stimulated by eCO2 in this ecosystem. The C budget of this mature woodland may be less affected by eCO2 than the young N-limited ecosystems that have been studied previously.},
author = {Drake, John E. and Macdonald, Catriona A. and Tjoelker, Mark G. and Reich, Peter B. and Singh, Brajesh K. and Anderson, Ian C. and Ellsworth, David S.},
doi = {10.1007/s10533-018-0457-7},
isbn = {1053301804},
issn = {0168-2563},
journal = {Biogeochemistry},
keywords = {Carbon cycle,Carbon dioxide,Mathematical model,Soil CO2efflux,Soil respiration},
month = {jun},
number = {1},
pages = {85--101},
publisher = {Springer International Publishing},
title = {{Three years of soil respiration in a mature eucalypt woodland exposed to atmospheric CO2 enrichment}},
url = {https://doi.org/10.1007/s10533-018-0457-7 http://link.springer.com/10.1007/s10533-018-0457-7},
volume = {139},
year = {2018}
}
@article{Drake2017b,
author = {Drake, Brandon L. and Hanson, David T. and Lowrey, Timothy K. and Sharp, Zachary D.},
doi = {10.1111/gcb.13449},
issn = {13541013},
journal = {Global Change Biology},
month = {feb},
number = {2},
pages = {782--792},
title = {{The carbon fertilization effect over a century of anthropogenic CO2 emissions: higher intracellular CO2 and more drought resistance among invasive and native grass species contrasts with increased water use efficiency for woody plants in the US Southwest}},
url = {http://doi.wiley.com/10.1111/gcb.13449},
volume = {23},
year = {2017}
}
@article{Drijfhout2015b,
abstract = {Abrupt transitions of regional climate in response to the gradual rise in atmospheric greenhouse gas concentrations are notoriously difficult to foresee. However, such events could be particularly challenging in view of the capacity required for society and ecosystems to adapt to them. We present, to our knowledge, the first systematic screening of the massive climate model ensemble informing the recent Intergovernmental Panel on Climate Change report, and reveal evidence of 37 forced regional abrupt changes in the ocean, sea ice, snow cover, permafrost, and terrestrial biosphere that arise after a certain global temperature increase. Eighteen out of 37 events occur for global warming levels of less than 2°, a threshold sometimes presented as a safe limit. Although most models predict one or more such events, any specific occurrence typically appears in only a few models. We find no compelling evidence for a general relation between the overall number of abrupt shifts and the level of global warming. However, we do note that abrupt changes in ocean circulation occur more often for moderate warming (less than 2°), whereas over land they occur more often for warming larger than 2°. Using a basic proportion test, however, we find that the number of abrupt shifts identified in Representative Concentration Pathway (RCP) 8.5 scenarios is significantly larger than in other scenarios of lower radiative forcing. This suggests the potential for a gradual trend of destabilization of the climate with respect to such shifts, due to increasing global mean temperature change.},
author = {Drijfhout, Sybren and Bathiany, Sebastian and Beaulieu, Claudie and Brovkin, Victor and Claussen, Martin and Huntingford, Chris and Scheffer, Marten and Sgubin, Giovanni and Swingedouw, Didier},
doi = {10.1073/pnas.1511451112},
isbn = {0027-8424},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {oct},
number = {43},
pages = {E5777--E5786},
pmid = {26460042},
title = {{Catalogue of abrupt shifts in Intergovernmental Panel on Climate Change climate models}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1511451112},
volume = {112},
year = {2015}
}
@article{DU2019697,
abstract = {A substantial number of experiments have so far been carried out to study the response of the C-N-P stoichiometry of terrestrial plants to the rising CO2 level of the earth. However, there is a need of systematic evaluation for assessing the impact of the elevated CO2 on plant C-N-P stoichiometry. In the present investigation, a comprehensive meta-analysis involving 386 published reports and including 4481 observations has been carried out. The goal of the research was to determine the response of plants to their C-N-P stoichiometry due to elevated levels of global atmospheric CO2. The results showed that rising CO2 altered the concentration of C (+2.19{\%}, P {\textless} 0.05), N (−9.73{\%}, P {\textless} 0.001) and P (−3.23{\%}, P {\textless} 0.001) and C:N (+13.29{\%}, P {\textless} 0.001) and N:P ratios (−7.32{\%}, P {\textless} 0.0001). Overall, a slightly increasing trend in the C:P ratio (P {\textgreater} 0.05) in the plant was observed. However, plant leaf, shoot and herbaceous type of plants showed more sensitivity to rising CO2. CO2 magnitude exhibited a positive effect (P {\textless} 0.05) on C:N ratio. Additionally, “CO2 acclimation” hypothesis as proposed by the authors of the current paper was also tested in the study. Results obtained, especially, show changes of C and N concentrations and C:P ratio to an obvious down-regulation for long-term CO2 fumigation. At spatial scales, a reduction of plant N concentration was found to be higher in the southern hemisphere. The CO2 enrichment methods affected the plant C-N-P stoichiometry. Compared to FACE (free-air CO2 enrichment), OTC (open top chamber) showed larger changes of C, N, P, and N:P. The results of the present study should, therefore, become helpful to offer a better understanding towards the response of the terrestrial plant C-N-P stoichiometry to an elevated global atmospheric CO2 in the future.},
annote = {added by A.Eliseev 22.01.2019},
author = {Du, Chenjun and Wang, Xiaodan and Zhang, Mengyao and Jing, Jie and Gao, Yongheng},
doi = {10.1016/j.scitotenv.2018.09.051},
issn = {00489697},
journal = {Science of The Total Environment},
keywords = {CO acclimation,Experiment condition,Meta-analysis,Plant stoichiometry,Rising CO,Spatial difference},
month = {feb},
pages = {697--708},
title = {{Effects of elevated CO2 on plant C–N–P stoichiometry in terrestrial ecosystems: A meta-analysis}},
url = {http://www.sciencedirect.com/science/article/pii/S0048969718334818 https://linkinghub.elsevier.com/retrieve/pii/S0048969718334818},
volume = {650},
year = {2019}
}
@article{Du2020,
author = {Du, Enzai and Terrer, C{\'{e}}sar and Pellegrini, Adam F. A. and Ahlstr{\"{o}}m, Anders and van Lissa, Caspar J. and Zhao, Xia and Xia, Nan and Wu, Xinhui and Jackson, Robert B.},
doi = {10.1038/s41561-019-0530-4},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {mar},
number = {3},
pages = {221--226},
title = {{Global patterns of terrestrial nitrogen and phosphorus limitation}},
url = {http://www.nature.com/articles/s41561-019-0530-4},
volume = {13},
year = {2020}
}
@article{Duan2020,
abstract = {Abstract A number of radiation modification approaches have been proposed to counteract anthropogenic warming by intentionally altering Earth's shortwave or longwave fluxes. While several previous studies have examined the climate effect of different radiation modification approaches, only a few have investigated the carbon cycle response. Our study examines the response of plant carbon uptake to four radiation modification approaches that are used to offset the global mean warming caused by a doubling of atmospheric CO2. Using the National Center for Atmospheric Research Community Earth System Model, we performed simulations that represent four idealized radiation modification options: solar constant reduction, sulfate aerosol increase (SAI), marine cloud brightening, and cirrus cloud thinning (CCT). Relative to the high CO2 state, all these approaches reduce gross primary production (GPP) and net primary production (NPP). In high latitudes, decrease in GPP is mainly due to the reduced plant growing season length, and in low latitudes, decrease in GPP is mainly caused by the enhanced nitrogen limitation due to surface cooling. The simulated GPP for sunlit leaves decreases for all approaches. Decrease in sunlit GPP is the largest for SAI which substantially decreases direct sunlight, and the smallest for CCT, which increases direct sunlight that reaches the land surface. GPP for shaded leaves increases in SAI associated with a substantial increase in surface diffuse sunlight, and decreases in all other cases. The combined effects of CO2 increase and radiation modification result in increases in primary production, indicating the dominant role of the CO2 fertilization effect on plant carbon uptake.},
author = {Duan, Lei and Cao, Long and Bala, Govindasamy and Caldeira, Ken},
doi = {10.1029/2019JD031883},
journal = {Journal of Geophysical Research: Atmospheres},
number = {9},
pages = {e2019JD031883},
title = {{A Model-Based Investigation of Terrestrial Plant Carbon Uptake Response to Four Radiation Modification Approaches}},
volume = {125},
year = {2020}
}
@article{ISI:000316015000001,
abstract = {Ocean acidification due to anthropogenic CO2 emissions is a dominant driver of long-term changes in pH in the open ocean, raising concern for the future of calcifying organisms, many of which are present in coastal habitats. However, changes in pH in coastal ecosystems result from a multitude of drivers, including impacts from watershed processes, nutrient inputs, and changes in ecosystem structure and metabolism. Interaction between ocean acidification due to anthropogenic CO2 emissions and the dynamic regional to local drivers of coastal ecosystems have resulted in complex regulation of pH in coastal waters. Changes in the watershed can, for example, lead to changes in alkalinity and CO2 fluxes that, together with metabolic processes and oceanic dynamics, yield high-magnitude decadal changes of up to 0.5 units in coastal pH. Metabolism results in strong diel to seasonal fluctuations in pH, with characteristic ranges of 0.3 pH units, with metabolically intense habitats exceeding this range on a daily basis. The intense variability and multiple, complex controls on pH implies that the concept of ocean acidification due to anthropogenic CO2 emissions cannot be transposed to coastal ecosystems directly. Furthermore, in coastal ecosystems, the detection of trends towards acidification is not trivial and the attribution of these changes to anthropogenic CO2 emissions is even more problematic. Coastal ecosystems may show acidification or basification, depending on the balance between the invasion of coastal waters by anthropogenic CO2, watershed export of alkalinity, organic matter and CO2, and changes in the balance between primary production, respiration and calcification rates in response to changes in nutrient inputs and losses of ecosystem components. Hence, we contend that ocean acidification from anthropogenic CO2 is largely an open-ocean syndrome and that a concept of anthropogenic impacts on marine pH, which is applicable across the entire ocean, from coastal to open-ocean environments, provides a superior framework to consider the multiple components of the anthropogenic perturbation of marine pH trajectories. The concept of anthropogenic impacts on seawater pH acknowledges that a regional focus is necessary to predict future trajectories in the pH of coastal waters and points at opportunities to manage these trajectories locally to conserve coastal organisms vulnerable to ocean acidification.},
author = {Duarte, Carlos M. and Hendriks, Iris E. and Moore, Tommy S. and Olsen, Ylva S. and Steckbauer, Alexandra and Ramajo, Laura and Carstensen, Jacob and Trotter, Julie A. and McCulloch, Malcolm},
doi = {10.1007/s12237-013-9594-3},
issn = {1559-2723},
journal = {Estuaries and Coasts},
keywords = {Alkalinity,Anthropogenic impacts,Eutrophication,Ocean acidification,Watershed changes,pH},
month = {mar},
number = {2},
pages = {221--236},
publisher = {Springer-Verlag},
title = {{Is Ocean Acidification an Open-Ocean Syndrome? Understanding Anthropogenic Impacts on Seawater pH}},
url = {http://link.springer.com/10.1007/s12237-013-9594-3},
volume = {36},
year = {2013}
}
@article{DunkleyJones2013,
abstract = {Constraining the greenhouse gas forcing, climatic warming and estimates of climate sensitivity across ancient large transient warming events is a major challenge to the palaeoclimate research community. Here we provide a new compilation and synthesis of the available marine proxy temperature data across the largest of these hyperthermals, the Paleocene-Eocene Thermal Maximum (PETM). This includes the application of consistent temperature calibrations to all data, including the most recent set of calibrations for archaeal lipid-derived palaeothermometry. This compilation provides the basis for an informed discussion of the likely range of PETM warming, the biases present in the existing record and an initial assessment of the geographical pattern of PETM ocean warming. To aid interpretation of the geographic variability of the proxy-derived estimates of PETM warming, we present a comparison of this data with the patterns of warming produced by high pCO2simulations of Eocene climates using the Hadley Centre atmosphere-ocean general circulation model (AOGCM) HadCM3L. On the basis of this comparison and taking into account the patterns of intermediate-water warming we estimate that the global mean surface temperature anomaly for the PETM is within the range of 4 to 5°C. {\textcopyright} 2013 Elsevier B.V.},
author = {{Dunkley Jones}, Tom and Lunt, Daniel J. and Schmidt, Daniela N. and Ridgwell, Andy and Sluijs, Appy and Valdes, Paul J. and Maslin, Mark},
doi = {10.1016/j.earscirev.2013.07.004},
isbn = {0012-8252},
issn = {00128252},
journal = {Earth-Science Reviews},
keywords = {Climate,Eocene,PETM,Paleocene,Warming},
month = {oct},
pages = {123--145},
title = {{Climate model and proxy data constraints on ocean warming across the Paleocene–Eocene Thermal Maximum}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012825213001207},
volume = {125},
year = {2013}
}
@article{Dupont2010,
abstract = {Ocean acidification has been proposed as a major threat for marine biodiversity. Hendriks et al. [Hendriks, I.E., Duarte, C.M., Alvarez, M., 2010. Vulnerability of marine biodiversity to ocean acidification: a meta-analysis. Estuarine, Coastal and Shelf Science, doi:10.1016/j.ecss.2009.11.022.] proposed an alternative view and suggested, based on a meta-analysis, that marine biota may be far more resistant to ocean acidification than hitherto believed. However, such a meta-analytical approach can mask more subtle features, for example differing sensitivities during the life-cycle of an organism. Using a similar metric on an echinoderm database, we show that key bottlenecks present in the life-cycle (e.g. larvae being more vulnerable than adults) and responsible for driving the whole species response may be hidden in a global meta-analysis. Our data illustrate that any ecological meta-analysis should be hypothesis driven, taking into account the complexity of biological systems, including all life-cycle stages and key biological processes. Available data allow us to conclude that near-future ocean acidification can/will have dramatic negative impact on some marine species, including echinoderms, with likely consequences at the ecosystem level.},
author = {Dupont, S. and Dorey, N. and Thorndyke, M.},
doi = {10.1016/j.ecss.2010.06.013},
issn = {02727714},
journal = {Estuarine, Coastal and Shelf Science},
month = {sep},
number = {2},
pages = {182--185},
publisher = {Academic Press},
title = {{What meta-analysis can tell us about vulnerability of marine biodiversity to ocean acidification?}},
url = {https://www.sciencedirect.com/science/article/pii/S0272771410002337 https://linkinghub.elsevier.com/retrieve/pii/S0272771410002337},
volume = {89},
year = {2010}
}
@article{Dussin2019,
abstract = {Recent observations have revealed significant fluctuations in near-shore hypoxia in the California Current Ecosystem (CCE). These fluctuations have been linked to changes in the biogeochemical properties (e.g. oxygen and nutrient contents) of the oceanic source waters of the California Current upwelling, and projections suggest the potential for decreased oxygen and increased nutrients in the source water under climate change. We examine both the separate and combined influences of these projected changes through a sequence of perturbation experiments using a regional coupled ocean dynamics/biogeochemistry (BGC) model of the CCE. The direct effect of a projected 5{\%} decline in source water oxygen is to expand the hypoxic area by 12.5{\%} in winter to 22.5{\%} in summer. This exceeds the impact of a +0.5{\%} nitrate enrichment of source waters, which expands the hypoxic area by 6.5{\%} to 12{\%} via stimulation of nearshore Net Primary Productivity (NPP), increased organic matter export, and subsequent enhanced remineralization and dissolved oxygen (DO) consumption at depth. The combined effect of these perturbations consistently surpasses the sum of the individual impacts, leading to 20{\%} to 32{\%} more hypoxic area. The combined biogeochemical impact greatly exceeds the response resulting from a 10{\%} strengthening in upwelling-favorable winds (+1{\%} in hypoxic area) or the decreased oxygen solubility associated with a 2∘C ocean warming (+3{\%}). These results emphasize the importance of improved constraints on dynamic biogeochemical changes projected along the boundaries of shelf ecosystems. While such changes are often viewed as secondary impacts of climate change relative to local warming or stratification changes, they may prove dominant drivers of coastal ecosystem change.},
author = {Dussin, R and Curchitser, E.N. and Stock, C.A. and {Van Oostende}, N},
doi = {10.1016/j.dsr2.2019.05.013},
issn = {09670645},
journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
month = {nov},
pages = {104590},
title = {{Biogeochemical drivers of changing hypoxia in the California Current Ecosystem}},
volume = {169-170},
year = {2019}
}
@article{Dymond2014,
abstract = {In British Columbia, Canada, a recent epidemic of mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902) caused widespread forest mortality. This epidemic was due in part to the changing climate, and damage from pests and diseases is expected to increase in the future. Therefore, we used a historical retrospective approach as a proxy to evaluate management options on reducing the forest health damage that may occur under a future changing climate. We assessed two landscape-scale strategies, intended to increase tree species diversity, for the response in ecosystem resilience and compared the results with the business-as-usual strategy. The assessment was based on simulation modelling of the Merritt Timber Supply Area for 1980?2060. We applied a strategy to increase the harvest of the most dominant tree species, plant more diverse species, and increase natural regeneration. This strategy resulted in greater ecological resilience (higher diversity and growing stocks), higher harvest rates, and higher, more consistent net revenue over time than the business-as-usual strategy or the strategy that only employed a diversity of planting. A sensitivity analysis indicated a high level of robustness in the results. Our study showed that it may not be necessary to compromise economic viability to reduce forest health risks and consequently improve socio-ecological resilience.},
annote = {doi: 10.1139/cjfr-2014-0146},
author = {Dymond, Caren C and Tedder, Sinclair and Spittlehouse, David L and Raymer, Brian and Hopkins, Katherine and McCallion, Katharine and Sandland, James},
doi = {10.1139/cjfr-2014-0146},
issn = {0045-5067},
journal = {Canadian Journal of Forest Research},
month = {jul},
number = {10},
pages = {1196--1205},
publisher = {NRC Research Press},
title = {{Diversifying managed forests to increase resilience}},
url = {https://doi.org/10.1139/cjfr-2014-0146},
volume = {44},
year = {2014}
}
@article{Dyonisius2020,
abstract = {Permafrost and methane hydrates are large, climate-sensitive old carbon reservoirs that have the potential to emit large quantities of methane, a potent greenhouse gas, as the Earth continues to warm. We present ice core isotopic measurements of methane (D14C, d13C, and dD) from the last deglaciation, which is a partial analog for modern warming. Our results show that methane emissions from old carbon reservoirs in response to deglacial warming were small ({\textless}19 teragrams of methane per year, 95{\%} confidence interval) and argue against similar methane emissions in response to future warming. Our results also indicate that methane emissions from biomass burning in the pre-Industrial Holocene were 22 to 56 teragrams of methane per year (95{\%} confidence interval), which is comparable to today.},
author = {Dyonisius, M. N. and Petrenko, V. V. and Smith, A. M. and Hua, Q. and Yang, B. and Schmitt, J. and Beck, J. and Seth, B. and Bock, M. and Hmiel, B. and Vimont, I. and Menking, J. A. and Shackleton, S. A. and Baggenstos, D. and Bauska, T. K. and Rhodes, R. H. and Sperlich, P. and Beaudette, R. and Harth, C. and Kalk, M. and Brook, E. J. and Fischer, H. and Severinghaus, J. P. and Weiss, R. F.},
doi = {10.1126/science.aax0504},
issn = {10959203},
journal = {Science},
number = {6480},
pages = {907--910},
pmid = {32079770},
title = {{Old carbon reservoirs were not important in the deglacial methane budget}},
volume = {367},
year = {2020}
}
@article{Earl2018,
abstract = {Fire regimes across the globe have great spatial and temporal variability, and these are influence by many factors including anthropogenic management, climate, and vegetation types. Here we utilize the satellite-based “active fire” product, from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors, to statistically analyze variability and trends in fire activity from the global to regional scales. We split up the regions by economic development, region/geographical land use, clusters of fire-abundant areas, or by religious/cultural influence. Weekly cycle tests are conducted to highlight and quantify part of the anthropogenic influence on fire regime across the world. We find that there is a strong statistically significant decline in 2001–2016 active fires globally linked to an increase in net primary productivity observed in northern Africa, along with global agricultural expansion and intensification, which generally reduces fire activity. There are high levels of variability, however. The large-scale regions exhibit either little change or decreasing in fire activity except for strong increasing trends in India and China, where rapid population increase is occurring, leading to agricultural intensification and increased crop residue burning. Variability in Canada has been linked to a warming global climate leading to a longer growing season and higher fuel loads. Areas with a strong weekly cycle give a good indication of where fire management is being applied most extensively, for example, the United States, where few areas retain a natural fire regime.},
author = {Earl, Nick and Simmonds, Ian},
doi = {10.1002/2017JD027749},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {fire activity,global scale,satellite data,trends},
month = {mar},
number = {5},
pages = {2524--2536},
title = {{Spatial and Temporal Variability and Trends in 2001–2016 Global Fire Activity}},
url = {https://onlinelibrary.wiley.com/doi/10.1002/2017JD027749},
volume = {123},
year = {2018}
}
@article{Eby2013,
abstract = {{\textless}p{\textgreater}{\textless}p{\textgreater}{\textless}strong{\textgreater}Abstract.{\textless}/strong{\textgreater} Both historical and idealized climate model experiments are performed with a variety of Earth system models of intermediate complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE and continue through to 2005. The standard simulations include changes in forcing from solar luminosity, Earth's orbital configuration, CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}, additional greenhouse gases, land use, and sulphate and volcanic aerosols. In spite of very different modelled pre-industrial global surface air temperatures, overall 20th century trends in surface air temperature and carbon uptake are reasonably well simulated when compared to observed trends. Land carbon fluxes show much more variation between models than ocean carbon fluxes, and recent land fluxes appear to be slightly underestimated. It is possible that recent modelled climate trends or climate–carbon feedbacks are overestimated resulting in too much land carbon loss or that carbon uptake due to CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater} and/or nitrogen fertilization is underestimated. Several one thousand year long, idealized, 2 × and 4 × CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater} experiments are used to quantify standard model characteristics, including transient and equilibrium climate sensitivities, and climate–carbon feedbacks. The values from EMICs generally fall within the range given by general circulation models. Seven additional historical simulations, each including a single specified forcing, are used to assess the contributions of different climate forcings to the overall climate and carbon cycle response. The response of surface air temperature is the linear sum of the individual forcings, while the carbon cycle response shows a non-linear interaction between land-use change and CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater} forcings for some models. Finally, the preindustrial portions of the last millennium simulations are used to assess historical model carbon-climate feedbacks. Given the specified forcing, there is a tendency for the EMICs to underestimate the drop in surface air temperature and CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater} between the Medieval Climate Anomaly and the Little Ice Age estimated from palaeoclimate reconstructions. This in turn could be a result of unforced variability within the climate system, uncertainty in the reconstructions of temperature and CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}, errors in the reconstructions of forcing used to drive the models, or the incomplete repr{\ldots}},
author = {Eby, M. and Weaver, A. J. and Alexander, K. and Zickfeld, K. and Abe-Ouchi, A. and Cimatoribus, A. A. and Crespin, E. and Drijfhout, S. S. and Edwards, N. R. and Eliseev, A. V. and Feulner, G. and Fichefet, T. and Forest, C. E. and Goosse, H. and Holden, P. B. and Joos, F. and Kawamiya, M. and Kicklighter, D. and Kienert, H. and Matsumoto, K. and Mokhov, I. I. and Monier, E. and Olsen, S. M. and Pedersen, J. O. P. and Perrette, M. and Philippon-Berthier, G. and Ridgwell, A. and Schlosser, A. and {Schneider von Deimling}, T. and Shaffer, G. and Smith, R. S. and Spahni, R. and Sokolov, A. P. and Steinacher, M. and Tachiiri, K. and Tokos, K. and Yoshimori, M. and Zeng, N. and Zhao, F.},
doi = {10.5194/cp-9-1111-2013},
journal = {Climate of the Past},
month = {may},
number = {3},
pages = {1111--1140},
title = {{Historical and idealized climate model experiments: an intercomparison of Earth system models of intermediate complexity}},
volume = {9},
year = {2013}
}
@article{Egleston2010,
abstract = {We derive explicit expressions of the Revelle factor and several other buffer factors of interest to climate change scientists and those studying ocean acidification. These buffer factors quantify the sensitivity of CO2 and H+ concentrations ([CO2] and [H+]) and CaCO3 saturation ($\Omega$) to changes in dissolved inorganic carbon concentration (DIC) and alkalinity (Alk). The explicit expressions of these buffer factors provide a convenient means to compare the degree of buffering of [CO2], [H+], and $\Omega$ in different regions of the oceans and at different times in the future and to gain insight into the buffering mechanisms. All six buffer factors have roughly similar values, and all reach an absolute minimum when DIC = Alk (pH ∼ 7.5). Surface maps of the buffer factors generally show stronger buffering capacity in the subtropical gyres relative to the polar regions. As the dissolution of anthropogenic CO2 increases the DIC of surface seawater over the next century, all the buffer factors will decrease, resulting in a much greater sensitivity to local variations in DIC and Alk. For example, diurnal and seasonal variations in pH and $\Omega$ caused by photosynthesis and respiration will be greatly amplified. Buffer factors provide convenient means to quantify the effect that changes in DIC and Alk have on seawater chemistry. They should also help illuminate the role that various physical and biological processes have in determining the oceanic response to an increase in atmospheric CO2.},
author = {Egleston, Eric S and Sabine, Christopher L and Morel, Fran{\c{c}}ois M M},
doi = {https://doi.org/10.1029/2008GB003407},
journal = {Global Biogeochemical Cycles},
keywords = {acidification,buffer factor,ocean chemistry},
number = {1},
title = {{Revelle revisited: Buffer factors that quantify the response of ocean chemistry to changes in DIC and alkalinity}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2008GB003407},
volume = {24},
year = {2010}
}
@article{Ehlert2017,
abstract = {AbstractThe ratio of global mean surface air temperature change to cumulative CO2 emissions, referred to as Transient Climate Response to Cumulative CO2 Emissions (TCRE), has been shown to be approximately constant on centennial time scales. The mechanisms behind this constancy are not well understood, but previous studies suggest that compensating effects of ocean heat and carbon fluxes, which are governed by the same ocean mixing processes, could be one cause for this approximate constancy. This hypothesis is investigated by forcing different versions of the University of Victoria Earth System Climate Model, which differ in the ocean mixing parameterization, with an idealized scenario of 1{\%} annually increasing atmospheric CO2 until quadrupling of the pre-industrial CO2 concentration and constant concentration thereafter. The relationship between surface air warming and cumulative emissions remains close to linear but the TCRE varies between model versions, spanning the range of 1.2-2.1 °C/EgC at the tim...},
author = {Ehlert, Dana and Zickfeld, Kirsten and Eby, Michael and Gillett, Nathan},
doi = {10.1175/JCLI-D-16-0247.1},
issn = {0894-8755},
journal = {Journal of Climate},
keywords = {Carbon cycle,Climate models},
month = {apr},
number = {8},
pages = {2921--2935},
title = {{The sensitivity of the proportionality between temperature change and cumulative CO2 emissions to ocean mixing}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0247.1},
volume = {30},
year = {2017}
}
@article{Ehlert2017c,
author = {Ehlert, Dana and Zickfeld, Kirsten},
doi = {10.1088/1748-9326/aa564a},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jan},
number = {1},
pages = {015002},
publisher = {IOP Publishing},
title = {{What determines the warming commitment after cessation of CO2 emissions?}},
url = {http://stacks.iop.org/1748-9326/12/i=1/a=015002?key=crossref.6066b34063f7fb5e4abf8e4f8031ec5a},
volume = {12},
year = {2017}
}
@article{Ekholm2016a,
abstract = {Solar radiation management (SRM) could provide a fast and low-cost option to mitigate global warming, but can also incur unwanted or unexpected climatic side-effects. As these side-effects involve substantial uncertainties, the optimal role of SRM cannot be yet determined. Here, we present probabilistic emission scenarios that limit global mean temperature increase to 2 °C under uncertainty on possible future SRM deployment. Three uncertainties relating to SRM deployment are covered: the start time, intensity and possible termination. We find that the uncertain SRM option allows very little additional GHG emissions before the SRM termination risk can be excluded, and the result proved robust over different hypothetical probability assumptions for SRM deployment. An additional CO2 concentration constraint, e.g. to mitigate ocean acidification, necessitates CO2 reductions even with strong SRM; but in such case SRM renders non-CO2 reductions unnecessary. This illustrates how the framing of climatic targets and available mitigation measures affect strongly the optimal mitigation strategies. The ability of SRM to decrease emission reduction costs is diminished by the uncertainty in SRM deployment and the possible concentration constraint, and also depends heavily on the assumed emission reduction costs. By holding SRM deployment time uncertain, we also find that carrying out safeguard emission reductions and delaying SRM deployment by 10 to 20 years increases reduction costs only moderately.},
author = {Ekholm, Tommi and Korhonen, Hannele},
doi = {10.1007/s10584-016-1828-5},
issn = {1573-1480},
journal = {Climatic Change},
number = {3},
pages = {503--515},
title = {{Climate change mitigation strategy under an uncertain Solar Radiation Management possibility}},
volume = {139},
year = {2016}
}
@article{Elberling2010a,
author = {Elberling, Bo and Christiansen, Hanne H. and Hansen, Birger U.},
doi = {10.1038/ngeo803},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {may},
number = {5},
pages = {332--335},
title = {{High nitrous oxide production from thawing permafrost}},
url = {http://www.nature.com/articles/ngeo803},
volume = {3},
year = {2010}
}
@article{Eliseev2008,
abstract = {The climate model of the Institute of Atmospheric Physics of the Russian Academy of Sciences (IAP RAS CM) has been supplemented with a module of soil thermal physics and the methane cycle, which takes into account the response of methane emissions from wetland ecosystems to climate changes. Methane emissions are allowed only from unfrozen top layers of the soil, with an additional constraint in the depth of the simulated layer. All wetland ecosystems are assumed to be water-saturated. The molar amount of the methane oxidized in the atmosphere is added to the simulated atmospheric concentration of CO2. A control preindustrial experiment and a series of numerical experiments for the 17th-21st centuries were conducted with the model forced by greenhouse gases and tropospheric sulfate aerosols. It is shown that the IAP RAS CM generally reproduces preindustrial and current characteristics of both seasonal thawing/freezing of the soil and the methane cycle. During global warming in the 21st century, the permafrost area is reduced by four million square kilometers. By the end of the 21st century, methane emissions from wetland ecosystems amount to 130-140 Mt CH4/ year for the preindustrial and current period increase to 170-200 MtCH4/year. In the aggressive anthropogenic forcing scenario A2, the atmospheric methane concentration grows steadily to 3900 ppb. In more moderate scenarios A1B and B1, the methane concentration increases until the mid-21st century, reaching -2100-2400 ppb, and then decreases. Methane oxidation in air results in a slight additional growth of the atmospheric concentration of carbon dioxide. Allowance for the interaction between processes in wetland ecosystems and the methane cycle in the IAP RAS CM leads to an additional atmospheric methane increase of 10-20{\%} depending on the anthropogenic forcing scenario and the time. The causes of this additional increase are the temperature dependence of integral methane production and the longer duration of a warm period in the soil. However, the resulting enhancement of the instantaneous greenhouse radiative forcing of atmospheric methane and an increase in the mean surface air temperature are small (globally {\textless} 0.1 W/m2and 0.05 K, respectively). {\textcopyright} MAIK Nauka 2008.},
author = {Eliseev, A. V. and Mokhov, I. I. and Arzhanov, M. M. and Demchenko, P. F. and Denisov, S. N.},
doi = {10.1134/S0001433808020011},
issn = {0001-4338},
journal = {Izvestiya, Atmospheric and Oceanic Physics},
month = {apr},
number = {2},
pages = {139--152},
title = {{Interaction of the methane cycle and processes in wetland ecosystems in a climate model of intermediate complexity}},
url = {http://link.springer.com/10.1134/S0001433808020011},
volume = {44},
year = {2008}
}
@article{Eliseev2014,
author = {Eliseev, A. V. and Mokhov, I. I. and Chernokulsky, A. V.},
doi = {10.1134/S1028334X14120034},
issn = {1028-334X},
journal = {Doklady Earth Sciences},
month = {dec},
number = {2},
pages = {1565--1569},
title = {{Influence of ground and peat fires on CO2 emissions into the atmosphere}},
url = {http://link.springer.com/10.1134/S1028334X14120034},
volume = {459},
year = {2014}
}
@article{Eliseev2014,
abstract = {Abstract. This paper presents ensemble simulations with the global climate model developed at the A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM). These simulations are forced by historical reconstructions of concentrations of well-mixed greenhouse gases (CO2, CH4, and N2O), sulfate aerosols (both in the troposphere and stratosphere), extent of crops and pastures, and total solar irradiance for AD 850–2005 (hereafter all years are taken as being AD) and by the Representative Concentration Pathway (RCP) scenarios for the same forcing agents until the year 2300. Our model implements GlobFIRM (Global FIRe Model) as a scheme for calculating characteristics of natural fires. Comparing to the original GlobFIRM model, in our implementation, the scheme is extended by a module accounting for CO2 release from soil during fires. The novel approach of our paper is to simulate natural fires in an ensemble fashion. Different ensemble members in the present paper are constructed by varying the values of parameters of the natural fires module. These members are constrained by the GFED-3.1 data set for the burnt area and CO2 release from fires and further subjected to Bayesian averaging. Our simulations are the first coupled model assessment of future changes in gross characteristics of natural fires. In our model, the present-day (1998–2011) global area burnt due to natural fires is (2.1 ± 0.4) × 106 km2 yr−1 (ensemble mean and intra-ensemble standard deviation are presented), and the respective CO2 emissions to the atmosphere are (1.4 ± 0.2) Pg C yr−1. The latter value is in agreement with the corresponding GFED estimates. The area burnt by natural fires is generally larger than the GFED estimates except in boreal Eurasia, where it is realistic, and in Australia, where it is smaller than these estimates. Regionally, the modelled CO2 emissions are larger (smaller) than the GFED estimates in Europe (in the tropics and north-eastern Eurasia). From 1998–2011 to 2091–2100, the ensemble mean global burnt area is increased by 13{\%} (28{\%}, 36{\%}, 51{\%}) under scenario RCP 2.6 (RCP 4.5, RCP 6.0, RCP 8.5). The corresponding global emissions increase is 14{\%} (29{\%}, 37{\%}, 42{\%}). From 2091–2100 to 2291–2300, under the mitigation scenario RCP 2.6 the ensemble mean global burnt area and the respective CO2 emissions slightly decrease, both by 5{\%} relative to their values in the period 2091–2100. In turn, under scenario RCP 4.5 (RCP 6.0, RCP 8.5) the ensemble mean burnt area in the period 2291–2100 is higher by 15{\%} (44{\%}, 83{\%}) than its mean value, and the ensemble mean CO2 emissions are correspondingly higher by 9{\%} (19{\%}, 31{\%}). The simulated changes of natural fire characteristics in the 21st–23rd centuries are associated mostly with the corresponding changes in boreal regions of Eurasia and North America. However, under the RCP 8.5 scenario, the increase of the burnt area and CO2 emissions in boreal regions during the 22nd and 23rd centuries is accompanied by the respective decreases in the tropics and subtropics.},
author = {Eliseev, A. V. and Mokhov, I. I. and Chernokulsky, A. V.},
doi = {10.5194/bg-11-3205-2014},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jun},
number = {12},
pages = {3205--3223},
title = {{An ensemble approach to simulate CO2 emissions from natural fires}},
url = {https://www.biogeosciences.net/11/3205/2014/},
volume = {11},
year = {2014}
}
@misc{Elkins2018,
author = {Elkins, James.W. and Dlugokencky, Ed and Hall, Bradley and Dutton, Geoff and Nance, David and Mondeel, Debra.J.},
publisher = {National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA/ESRL)},
title = {{Combined Nitrous Oxide data from the NOAA/ESRL Global Monitoring Division}},
url = {https://www.esrl.noaa.gov/gmd/hats/combined/N2O.html},
urldate = {2019-01-24},
year = {2018}
}
@article{Elling2019,
abstract = {A negative carbon isotope excursion recorded in terrestrial and marine archives reflects massive carbon emissions into the exogenic carbon reservoir during the Paleocene-Eocene Thermal Maximum. Yet, discrepancies in carbon isotope excursion estimates from different sample types lead to substantial uncertainties in the source, scale, and timing of carbon emissions. Here we show that membrane lipids of marine planktonic archaea reliably record both the carbon isotope excursion and surface ocean warming during the Paleocene-Eocene Thermal Maximum. Novel records of the isotopic composition of crenarchaeol constrain the global carbon isotope excursion magnitude to −4.0 ± 0.4‰, consistent with emission of {\textgreater}3000 Pg C from methane hydrate dissociation or {\textgreater}4400 Pg C for scenarios involving emissions from geothermal heating or oxidation of sedimentary organic matter. A pre-onset excursion in the isotopic composition of crenarchaeol and ocean temperature highlights the susceptibility of the late Paleocene carbon cycle to perturbations and suggests that climate instability preceded the Paleocene-Eocene Thermal Maximum.},
author = {Elling, Felix J. and Gottschalk, Julia and Doeana, Katiana D. and Kusch, Stephanie and Hurley, Sarah J. and Pearson, Ann},
doi = {10.1038/s41467-019-12553-3},
issn = {20411723},
journal = {Nature Communications},
number = {1},
pages = {1--10},
pmid = {31586063},
publisher = {Springer US},
title = {{Archaeal lipid biomarker constraints on the Paleocene-Eocene carbon isotope excursion}},
url = {http://dx.doi.org/10.1038/s41467-019-12553-3},
volume = {10},
year = {2019}
}
@article{ELLISON201751,
abstract = {Forest-driven water and energy cycles are poorly integrated into regional, national, continental and global decision-making on climate change adaptation, mitigation, land use and water management. This constrains humanity's ability to protect our planet's climate and life-sustaining functions. The substantial body of research we review reveals that forest, water and energy interactions provide the foundations for carbon storage, for cooling terrestrial surfaces and for distributing water resources. Forests and trees must be recognized as prime regulators within the water, energy and carbon cycles. If these functions are ignored, planners will be unable to assess, adapt to or mitigate the impacts of changing land cover and climate. Our call to action targets a reversal of paradigms, from a carbon-centric model to one that treats the hydrologic and climate-cooling effects of trees and forests as the first order of priority. For reasons of sustainability, carbon storage must remain a secondary, though valuable, by-product. The effects of tree cover on climate at local, regional and continental scales offer benefits that demand wider recognition. The forest- and tree-centered research insights we review and analyze provide a knowledge-base for improving plans, policies and actions. Our understanding of how trees and forests influence water, energy and carbon cycles has important implications, both for the structure of planning, management and governance institutions, as well as for how trees and forests might be used to improve sustainability, adaptation and mitigation efforts.},
author = {Ellison, David and Morris, Cindy E and Locatelli, Bruno and Sheil, Douglas and Cohen, Jane and Murdiyarso, Daniel and Gutierrez, Victoria and van Noordwijk, Meine and Creed, Irena F and Pokorny, Jan and Gaveau, David and Spracklen, Dominick V and Tobella, Aida Bargu{\'{e}}s and Ilstedt, Ulrik and Teuling, Adriaan J and Gebrehiwot, Solomon Gebreyohannis and Sands, David C and Muys, Bart and Verbist, Bruno and Springgay, Elaine and Sugandi, Yulia and Sullivan, Caroline A},
doi = {10.1016/j.gloenvcha.2017.01.002},
issn = {0959-3780},
journal = {Global Environmental Change},
keywords = {Adaptation,Carbon,Climate,Energy,Forest,Mitigation,Reforestation,Sustainability,Water},
pages = {51--61},
title = {{Trees, forests and water: Cool insights for a hot world}},
url = {http://www.sciencedirect.com/science/article/pii/S0959378017300134},
volume = {43},
year = {2017}
}
@article{Elsig2009,
abstract = {Reconstructions of atmospheric CO(2) concentrations based on Antarctic ice cores reveal significant changes during the Holocene epoch, but the processes responsible for these changes in CO(2) concentrations have not been unambiguously identified. Distinct characteristics in the carbon isotope signatures of the major carbon reservoirs (ocean, biosphere, sediments and atmosphere) constrain variations in the CO(2) fluxes between those reservoirs. Here we present a highly resolved atmospheric delta(13)C record for the past 11,000 years from measurements on atmospheric CO(2) trapped in an Antarctic ice core. From mass-balance inverse model calculations performed with a simplified carbon cycle model, we show that the decrease in atmospheric CO(2) of about 5 parts per million by volume (p.p.m.v.). The increase in delta(13)C of about 0.25 per thousand during the early Holocene is most probably the result of a combination of carbon uptake of about 290 gigatonnes of carbon by the land biosphere and carbon release from the ocean in response to carbonate compensation of the terrestrial uptake during the termination of the last ice age. The 20 p.p.m.v. increase of atmospheric CO(2) and the small decrease in delta(13)C of about 0.05 per thousand during the later Holocene can mostly be explained by contributions from carbonate compensation of earlier land-biosphere uptake and coral reef formation, with only a minor contribution from a small decrease of the land-biosphere carbon inventory.},
author = {Elsig, Joachim and Schmitt, Jochen and Leuenberger, Daiana and Schneider, Robert and Eyer, Marc and Leuenberger, Markus and Joos, Fortunat and Fischer, Hubertus and Stocker, Thomas F.},
doi = {10.1038/nature08393},
issn = {0028-0836},
journal = {Nature},
month = {sep},
number = {7263},
pages = {507--510},
title = {{Stable isotope constraints on Holocene carbon cycle changes from an Antarctic ice core}},
url = {http://www.nature.com/articles/nature08393},
volume = {461},
year = {2009}
}
@article{Engram2020,
author = {Engram, M. and {Walter Anthony}, K. M. and Sachs, T. and Kohnert, K. and Serafimovich, A. and Grosse, G. and Meyer, F. J.},
doi = {10.1038/s41558-020-0762-8},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jun},
number = {6},
pages = {511--517},
title = {{Remote sensing northern lake methane ebullition}},
url = {http://www.nature.com/articles/s41558-020-0762-8},
volume = {10},
year = {2020}
}
@article{Erb2018,
abstract = {Analyses of potential and actual biomass stocks indicate that trade-offs exist between conserving carbon stocks on managed land and raising the contribution of biomass to raw material and energy supply for the mitigation of climate change.},
author = {Erb, Karl-Heinz and Kastner, Thomas and Plutzar, Christoph and Bais, Anna Liza S. and Carvalhais, Nuno and Fetzel, Tamara and Gingrich, Simone and Haberl, Helmut and Lauk, Christian and Niedertscheider, Maria and Pongratz, Julia and Thurner, Martin and Luyssaert, Sebastiaan},
doi = {10.1038/nature25138},
issn = {0028-0836},
journal = {Nature},
month = {jan},
number = {7686},
pages = {73--76},
pmid = {29258288},
publisher = {Nature Publishing Group},
title = {{Unexpectedly large impact of forest management and grazing on global vegetation biomass}},
url = {http://dx.doi.org/10.1038/nature25138 http://www.nature.com/articles/nature25138},
volume = {553},
year = {2018}
}
@article{Etiope2019,
abstract = {Abstract. Methane (CH4) is a powerful greenhouse gas, whose natural and anthropogenic emissions contribute {\~{}}20{\%} to global radiative forcing. Its atmospheric budget (sources and sinks), however, has large uncertainties. Inverse modelling, using atmospheric CH4 trends, spatial gradients and isotopic source signatures, has recently improved the major source estimates and their spatial-temporal variation. Nevertheless, isotopic data lack CH4 source representativeness for many sources, and CH4 source attribution is affected by incomplete knowledge of the spatial distribution of some sources, especially those related to fossil (radiocarbon-free) and microbial gas. This gap is particularly wide for geological CH4 seepage, i.e., the natural degassing of hydrocarbons from the Earth's crust. While geological seepage is widely considered the second most important natural CH4 source after wetlands, it has been mostly neglected in top-down CH4 budget studies, partly given the lack of detailed a priori gridded emission maps. Here, we report for the first time global gridded maps of geological CH4 sources, including emission and isotopic data. The 1°x1° maps include the four main categories of natural geo-CH4 emission: (a) onshore hydrocarbon macro-seeps, including mud volcanoes, (b) submarine (offshore) seepage, (c) diffuse microseepage and (d) geothermal manifestations. An inventory of point sources and area sources was developed for each category, defining areal distribution (activity), CH4 fluxes (emission factors) and its stable C isotope composition ($\delta$13C-CH4). These parameters were determined considering geological factors that control methane origin and seepage (e.g., petroleum fields, sedimentary basins, high heat flow regions, faults, seismicity). The global geo-source map reveals that the regions with the highest CH4 emissions are all located in the northern hemisphere, in North America, the Caspian region, Europe, and in the East Siberian Arctic Shelf. The globally gridded CH4 emission estimate (37Tgyear{\&}minus;1 exclusively based on data and modeling specifically targeted for gridding, and 43{\&}ndash;50Tgyear{\&}minus;1 when extrapolated to also account for onshore and submarine seeps with no location specific measurements available) is compatible with published ranges derived by top-down and bottom-up procedures. Improved activity and emission factor data allowed to refine previously published mud volcanoes and microseepage emission estimates. The emission-wei{\ldots}},
author = {Etiope, Giuseppe and Ciotoli, Giancarlo and Schwietzke, Stefan and Schoell, Martin},
doi = {10.5194/essd-11-1-2019},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {jan},
number = {1},
pages = {1--22},
title = {{Gridded maps of geological methane emissions and their isotopic signature}},
url = {https://www.earth-syst-sci-data.net/11/1/2019/},
volume = {11},
year = {2019}
}
@article{doi:10.1002/2016GL071930,
abstract = {New calculations of the radiative forcing (RF) are presented for the three main well-mixed greenhouse gases, methane, nitrous oxide, and carbon dioxide. Methane's RF is particularly impacted because of the inclusion of the shortwave forcing; the 1750-2011 RF is about 25{\%} higher (increasing from 0.48Wm −2 to 0.61Wm −2) compared to the value in the Intergovernmental Panel on Climate Change (IPCC) 2013 assessment; the 100year global warming potential is 14{\%} higher than the IPCC value. We present new simplified expressions to calculate RF. Unlike previous expressions used by IPCC, the new ones include the overlap between CO 2 and N 2 O; for N 2 O forcing, the CO 2 overlap can be as important as the CH 4 overlap. The 1750-2011 CO 2 RF is within 1{\%} of IPCC's value but is about 10{\%} higher when CO 2 amounts reach 2000ppm, a value projected to be possible under the extended RCP8.5 scenario.},
author = {Etminan, M and Myhre, G and Highwood, E J J and Shine, K P P},
doi = {10.1002/2016GL071930},
isbn = {10.1002/2016},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {methane,radiative forcing},
month = {dec},
number = {24},
pages = {12614--12623},
title = {{Radiative forcing of carbon dioxide, methane, and nitrous oxide: A significant revision of the methane radiative forcing}},
url = {http://doi.wiley.com/10.1002/2016GL071930 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016GL071930},
volume = {43},
year = {2016}
}
@article{Fagundes2020,
abstract = {Climate change is expected to warm, deoxygenate, and acidify ocean waters. Global climate models (GCMs) predict future conditions at large spatial scales, and these predictions are then often used to parameterize laboratory experiments designed to assess biological and ecological responses to future change. However, nearshore ecosystems are affected by a range of physical processes such as tides, local winds, and surface and internal waves, causing local variability in conditions that often exceeds global climate models. Predictions of future climatic conditions at local scales, the most relevant to ecological responses, are largely lacking. To fill this critical gap, we developed a 2D implementation of the Regional Ocean Modeling System (ROMS) to downscale global climate predictions across all Representative Concentration Pathway (RCP) scenarios to smaller spatial scales, in this case the scale of a temperate reef in the northeastern Pacific. To assess the potential biological impacts of local climate variability, we then used the results from different climate scenarios to estimate how climate change may affect the survival, growth, and fertilization of a representative marine benthic invertebrate, the red abalone Haliotis rufescens, to a highly varying multi-stressor environment. We found that high frequency variability in temperature, dissolved oxygen (DO), and pH increases as pCO2 increases in the atmosphere. Extreme temperature and pH conditions are generally not expected until RCP 4.5 or greater, while frequent exposure to low DO is already occurring. In the nearshore environment simulation, strong RCP scenarios can affect red abalone growth as well as reduce fertilization during extreme conditions when compared to global scale simulations.},
author = {Fagundes, Matheus and Litvin, S Y and Micheli, F and {De Leo}, G and Boch, C A and Barry, J P and Omidvar, S and Woodson, C B},
doi = {10.1038/s41598-020-71169-6},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {14227},
title = {{Downscaling global ocean climate models improves estimates of exposure regimes in coastal environments}},
url = {https://doi.org/10.1038/s41598-020-71169-6 http://www.nature.com/articles/s41598-020-71169-6},
volume = {10},
year = {2020}
}
@article{Fajardy2017,
abstract = {Negative emissions technologies (NETs) in general and bioenergy with CO2 capture and storage (BECCS) in particular are commonly regarded as vital yet controversial to meeting our climate goals. In this contribution we present a whole-systems analysis of the BECCS value chain associated with cultivation, harvesting, transport and conversion in dedicated biomass power stations in conjunction with CCS, of a range of biomass resources-both dedicated energy crops (miscanthus, switchgrass, short rotation coppice willow), and agricultural residues (wheat straw). We explicitly consider the implications of sourcing the biomass from different regions, climates and land types. The water, carbon and energy footprints of each value chain were calculated, and their impact on the overall system water, carbon and power efficiencies was evaluated. An extensive literature review was performed and a statistical analysis of the available data is presented. In order to describe the dynamic greenhouse gas balance of such a system, a yearly accounting of the emissions was performed over the lifetime of a BECCS facility, and the carbon "breakeven time" and lifetime net CO2 removal from the atmosphere were determined. The effects of direct and indirect land use change were included, and were found to be a key determinant of the viability of a BECCS project. Overall we conclude that, depending on the conditions of its deployment, BECCS could lead to both carbon positive and negative results. The total quantity of CO2 removed from the atmosphere over the project lifetime and the carbon breakeven time were observed to be highly case specific. This has profound implications for the policy frameworks required to incentivise and regulate the widespread deployment of BECCS technology. The results of a sensitivity analysis on the model combined with the investigation of alternate supply chain scenarios elucidated key levers to improve the sustainability of BECCS: (1) measuring and limiting the impacts of direct and indirect land use change, (2) using carbon neutral power and organic fertilizer, (3) minimising biomass transport, and prioritising sea over road transport, (4) maximising the use of carbon negative fuels, and (5) exploiting alternative biomass processing options, e.g., natural drying or torrefaction. A key conclusion is that, regardless of the biomass and region studied, the sustainability of BECCS relies heavily on intelligent management of the supply chain.},
author = {Fajardy, Mathilde and {Mac Dowell}, Niall},
doi = {10.1039/c7ee00465f},
issn = {17545706},
journal = {Energy and Environmental Science},
number = {6},
pages = {1389--1426},
publisher = {Royal Society of Chemistry},
title = {{Can BECCS deliver sustainable and resource efficient negative emissions?}},
volume = {10},
year = {2017}
}
@misc{Fan2019,
abstract = {Changes in terrestrial tropical carbon stocks have an important role in the global carbon budget. However, current observational tools do not allow accurate and large-scale monitoring of the spatial distribution and dynamics of carbon stocks1. Here, we used low-frequency L-band passive microwave observations to compute a direct and spatially explicit quantification of annual aboveground carbon (AGC) fluxes and show that the tropical net AGC budget was approximately in balance during 2010 to 2017, the net budget being composed of gross losses of −2.86 PgC yr−1 offset by gross gains of −2.97 PgC yr−1 between continents. Large interannual and spatial fluctuations of tropical AGC were quantified during the wet 2011 La Ni{\~{n}}a year and throughout the extreme dry and warm 2015–2016 El Ni{\~{n}}o episode. These interannual fluctuations, controlled predominantly by semiarid biomes, were shown to be closely related to independent global atmospheric CO2 growth-rate anomalies (Pearson's r = 0.86), highlighting the pivotal role of tropical AGC in the global carbon budget.},
author = {Fan, Lei and Wigneron, Jean Pierre and Ciais, Philippe and Chave, J{\'{e}}r{\^{o}}me and Brandt, Martin and Fensholt, Rasmus and Saatchi, Sassan S. and Bastos, Ana and Al-Yaari, Amen and Hufkens, Koen and Qin, Yuanwei and Xiao, Xiangming and Chen, Chi and Myneni, Ranga B. and Fernandez-Moran, Roberto and Mialon, Arnaud and Rodriguez-Fernandez, N. J. and Kerr, Yann and Tian, Feng and Pe{\~{n}}uelas, Josep},
booktitle = {Nature Plants},
doi = {10.1038/s41477-019-0478-9},
issn = {20550278},
month = {sep},
number = {9},
pages = {944--951},
pmid = {31358958},
title = {{Satellite-observed pantropical carbon dynamics}},
url = {http://www.nature.com/articles/s41477-019-0478-9},
volume = {5},
year = {2019}
}
@article{Fang2017,
abstract = {Climate variability associated with the El Ni{\~{n}}o-Southern Oscillation (ENSO) and its consequent impacts on land carbon sink interannual variability have been used as a basis for investigating carbon cycle responses to climate variability more broadly, and to inform the sensitivity of the tropical carbon budget to climate change. Past studies have presented opposing views about whether temperature or precipitation is the primary factor driving the response of the land carbon sink to ENSO. Here, we show that the dominant driver varies with ENSO phase. Whereas tropical temperature explains sink dynamics following El Ni{\~{n}}o conditions ( r TG,P = 0.59, p {\textless} 0.01), the post La Ni{\~{n}}a sink is driven largely by tropical precipitation ( r PG,T = −0.46, p = 0.04). This finding points to an ENSO-phase-dependent interplay between water availability and temperature in controlling the carbon uptake response to climate variations in tropical ecosystems. We further find that none of a suite of ten contemporary terrestrial biosphere models captures these ENSO-phase-dependent responses, highlighting a key uncertainty in modeling climate impacts on the future of the global land carbon sink.},
author = {Fang, Yuanyuan and Michalak, Anna M. and Schwalm, Christopher R. and Huntzinger, Deborah N. and Berry, Joseph A. and Ciais, Philippe and Piao, Shilong and Poulter, Benjamin and Fisher, Joshua B. and Cook, Robert B. and Hayes, Daniel and Huang, Maoyi and Ito, Akihiko and Jain, Atul and Lei, Huimin and Lu, Chaoqun and Mao, Jiafu and Parazoo, Nicholas C. and Peng, Shushi and Ricciuto, Daniel M. and Shi, Xiaoying and Tao, Bo and Tian, Hanqin and Wang, Weile and Wei, Yaxing and Yang, Jia},
doi = {10.1088/1748-9326/aa6e8e},
issn = {1748-9326},
journal = {Environmental Research Letters},
keywords = {Climate-carbon feedback,El Ni{\~{n}}o-Southern Oscillation (ENSO),precipitation,temperature,tropical ecosystems},
month = {jun},
number = {6},
pages = {064007},
title = {{Global land carbon sink response to temperature and precipitation varies with ENSO phase}},
url = {http://stacks.iop.org/1748-9326/12/i=6/a=064007?key=crossref.e1bdd82d6181d08581cbf91f674f9764},
volume = {12},
year = {2017}
}
@misc{FAOSTAT2019,
address = {Rome, Italy},
author = {FAO},
publisher = {The Food and Agriculture Organization of the United Nations (FAO)},
title = {{FAOSTAT: Emissions – Agriculture, Emissions – Land Use, Trade (Crops and livestock products), Population, Agri-Environmental Indicators (Livestock Manure)}},
url = {http://www.fao.org/faostat/en/{\#}data},
year = {2019}
}
@article{Farias2015,
abstract = {Seasonal and inter-annual variabilities of biogeochemical variables, including nitrous oxide (N2O), an important climate active gas, were analyzed during monthly observations between 2002 and 2012 at an ocean Time-Series station in the coastal upwelling area off central Chile (36° 30.8′; 73° 15′). Oxygen, N2O, nutrients and chlorophyll-a (Chl-a) showed clear seasonal variability associated with upwelling favorable winds (spring–summer) and also inter-annual variability, which in the case of N2O was clearly observed during the occurrence of N2O hotspots with saturation levels of up to 4849{\%}. These hotspots consistently took place during the upwelling-favorable periods in 2004, 2006, 2008, 2010 and 2011, below the mixed layer (15–50 m depth) in waters with hypoxia and some accumulation. The N2O hotspots displayed excesses of N2O ($\Delta$N2O) three times higher than the average monthly anomalies (2002–2012). Estimated relationships of $\Delta$N2O versus apparent oxygen utilization (AOU), and $\Delta$N2O versus suggest that aerobic ammonium oxidation (AAO) and partial denitrification are the processes responsible for high N2O accumulation in subsurface water. Chl-a levels were reasonably correlated with the presence of the N2O hotspots, suggesting that microbial activities fuelled by high availability of organic matters lead to high N2O production. As a result, this causes a substantial N2O efflux into the atmosphere of up to 260 $\mu$mol m−2 d−1. The N2O hotspots are transient events or hot moments, which may occur more frequently than they are observed. If so, this upwelling area is producing and emitting greater than expected amounts of N2O and is therefore an important N2O source that should be considered in the global atmospheric N2O balance.},
author = {Far{\'{i}}as, L and Besoain, V and Garc{\'{i}}a-Loyola, Sebasti{\'{a}}n},
doi = {10.1088/1748-9326/10/4/044017},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {apr},
number = {4},
pages = {044017},
publisher = {IOP Publishing},
title = {{Presence of nitrous oxide hotspots in the coastal upwelling area off central Chile: an analysis of temporal variability based on ten years of a biogeochemical time series}},
url = {http://dx.doi.org/10.1088/1748-9326/10/4/044017 http://stacks.iop.org/1748-9326/10/i=4/a=044017?key=crossref.9ad05143b3884eef5a245a6a1d27e256 https://iopscience.iop.org/article/10.1088/1748-9326/10/4/044017},
volume = {10},
year = {2015}
}
@article{Fargione2018,
abstract = {Limiting climate warming to {\&}lt;2°C requires increased mitigation efforts, including land stewardship, whose potential in the United States is poorly understood. We quantified the potential of natural climate solutions (NCS)—21 conservation, restoration, and improved land management interventions on natural and agricultural lands—to increase carbon storage and avoid greenhouse gas emissions in the United States. We found a maximum potential of 1.2 (0.9 to 1.6) Pg CO2e year−1, the equivalent of 21{\%} of current net annual emissions of the United States. At current carbon market prices (USD 10 per Mg CO2e), 299 Tg CO2e year−1 could be achieved. NCS would also provide air and water filtration, flood control, soil health, wildlife habitat, and climate resilience benefits.},
author = {Fargione, Joseph E and Bassett, Steven and Boucher, Timothy and Bridgham, Scott D and Conant, Richard T and Cook-Patton, Susan C and Ellis, Peter W and Falcucci, Alessandra and Fourqurean, James W and Gopalakrishna, Trisha and Gu, Huan and Henderson, Benjamin and Hurteau, Matthew D and Kroeger, Kevin D and Kroeger, Timm and Lark, Tyler J and Leavitt, Sara M and Lomax, Guy and McDonald, Robert I and Megonigal, J Patrick and Miteva, Daniela A and Richardson, Curtis J and Sanderman, Jonathan and Shoch, David and Spawn, Seth A and Veldman, Joseph W and Williams, Christopher A and Woodbury, Peter B and Zganjar, Chris and Baranski, Marci and Elias, Patricia and Houghton, Richard A and Landis, Emily and McGlynn, Emily and Schlesinger, William H and Siikamaki, Juha V and Sutton-Grier, Ariana E and Griscom, Bronson W},
doi = {10.1126/sciadv.aat1869},
journal = {Science Advances},
month = {nov},
number = {11},
pages = {eaat1869},
title = {{Natural climate solutions for the United States}},
volume = {4},
year = {2018}
}
@article{doi:10.1111/j.1365-2486.2005.01011.x,
abstract = {Abstract Carbon sequestration programs, including afforestation and reforestation, are gaining attention globally and will alter many ecosystem processes, including water yield. Some previous analyses have addressed deforestation and water yield, while the effects of afforestation on water yield have been considered for some regions. However, to our knowledge no systematic global analysis of the effects of afforestation on water yield has been undertaken. To assess and predict these effects globally, we analyzed 26 catchment data sets with 504 observations, including annual runoff and low flow. We examined changes in the context of several variables, including original vegetation type, plantation species, plantation age, and mean annual precipitation (MAP). All of these variables should be useful for understanding and modeling the effects of afforestation on water yield. We found that annual runoff was reduced on average by 44{\%} (±3{\%}) and 31{\%} (±2{\%}) when grasslands and shrublands were afforested, respectively. Eucalypts had a larger impact than other tree species in afforested grasslands (P=0.002), reducing runoff (90) by 75{\%} (±10{\%}), compared with a 40{\%} (±3{\%}) average decrease with pines. Runoff losses increased significantly with plantation age for at least 20 years after planting, whether expressed as absolute changes (mm) or as a proportion of predicted runoff ({\%}) (P{\textless}0.001). For grasslands, absolute reductions in annual runoff were greatest at wetter sites, but proportional reductions were significantly larger in drier sites (P{\textless}0.01 and P{\textless}0.001, respectively). Afforestation effects on low flow were similar to those on total annual flow, but proportional reductions were even larger for low flow (P{\textless}0.001). These results clearly demonstrate that reductions in runoff can be expected following afforestation of grasslands and shrublands and may be most severe in drier regions. Our results suggest that, in a region where natural runoff is less than 10{\%} of MAP, afforestation should result in a complete loss of runoff; where natural runoff is 30{\%} of precipitation, it will likely be cut by half or more when trees are planted. The possibility that afforestation could cause or intensify water shortages in many locations is a tradeoff that should be explicitly addressed in carbon sequestration programs.},
author = {Farley, Kathleen A and Jobbagy, Esteban G. and Jackson, Robert B},
doi = {10.1111/j.1365-2486.2005.01011.x},
issn = {1354-1013},
journal = {Global Change Biology},
keywords = {afforestation,land-use change,plantation,runoff,water yield},
month = {oct},
number = {10},
pages = {1565--1576},
title = {{Effects of afforestation on water yield: a global synthesis with implications for policy}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2005.01011.x http://doi.wiley.com/10.1111/j.1365-2486.2005.01011.x},
volume = {11},
year = {2005}
}
@article{Farrior2015,
author = {Farrior, Caroline E. and Rodriguez-Iturbe, Ignacio and Dybzinski, Ray and Levin, Simon A. and Pacala, Stephen W.},
doi = {10.1073/pnas.1506262112},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {jun},
number = {23},
pages = {7213--7218},
title = {{Decreased water limitation under elevated CO2 amplifies potential for forest carbon sinks}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1506262112},
volume = {112},
year = {2015}
}
@article{Fassbender2017,
author = {Fassbender, Andrea J. and Sabine, Christopher L. and Palevsky, Hilary I.},
doi = {10.1002/2017GL074389},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {aug},
number = {16},
pages = {8404--8413},
title = {{Nonuniform ocean acidification and attenuation of the ocean carbon sink}},
url = {http://doi.wiley.com/10.1002/2017GL074389},
volume = {44},
year = {2017}
}
@article{Fassbender2018,
abstract = {Fingerprinting ocean acidification (OA) in U.S. West Coast waters is extremely challenging due to the large magnitude of natural carbonate chemistry variations common to these regions. Additionally, quantifying a change requires information about the initial conditions, which is not readily available in most coastal systems. In an effort to address this issue, we have collated high-quality, publicly-available data to characterize the modern seasonal carbonate chemistry variability in marine surface waters of the Pacific Northwest. Underway ship data from Version 4 of the Surface Ocean CO2 Atlas, discrete observations from various sampling platforms, and sustained measurements from regional moorings were incorporated to provide {\~{}}{\&}thinsp;100,000 inorganic carbon observations from which modern seasonal cycles were estimated. Underway ship and discrete observations were merged and gridded to a 0.1°{\&}thinsp;×{\&}thinsp;0.1° scale. Eight unique regions were identified and seasonal cycles from grid cells within each region were averaged. Data from nine surface moorings were also compiled and used to develop robust estimates of mean seasonal cycles for comparison with the eight regions. This manuscript describes our methodology and the resulting mean seasonal cycles for multiple OA metrics in an effort to provide large-scale, environmental context for ongoing research, adaptation, and management efforts throughout the Pacific Northwest. Major findings include the identification of unique chemical characteristics across the study domain. There is a clear increase in the ratio of dissolved inorganic carbon (DIC) to total alkalinity (TA) and in the seasonal cycle amplitude of carbonate system parameters when moving from the open ocean North Pacific into the Salish Sea. Due to the logarithmic nature of the pH scale (pH{\&}thinsp;={\&}thinsp;{\&}minus;log10[H+], where [H+] is the hydrogen ion concentration), lower annual mean pH values (associated with elevated DIC{\&}thinsp;:{\&}thinsp;TA) coupled with larger magnitude seasonal pH cycles results in seasonal [H+] ranges that are {\~{}}{\&}thinsp;27 times larger in Hood Canal than in the neighboring North Pacific open ocean. Organisms living in the Salish Sea are thus exposed to much larger seasonal acidity changes than those living in nearby open ocean waters. Additionally, our findings suggest that lower buffering capacities in the Salish Sea make these waters less efficient at absorbing anthropogenic carbon than open ocean waters at the same latitude. All data used in this analysis are publically available at the following websites: • Surface Ocean CO2 Atlas Version 4 coastal data, doi:10.1594/PANGAEA.866856; • National Oceanic and Atmospheric Administration (NOAA) West Coast Ocean Acidification cruise data, doi:10.3334/CDIAC/otg.CLIVAR{\_}NACP{\_}West{\_}Coast{\_}Cruise{\_}2007; doi:10.3334/CDIAC/OTG.COAST{\_}WCOA2011; doi:10.3334/CDIAC/OTG.COAST{\_}WCOA2012; doi:10.7289/V5C53HXP; • University of Washington (UW) and Washington Ocean Acidification Center cruise data, doi:10.5281/zenodo.1184657; • Washington State Department of Ecology seaplane data, 10.5281/zenodo.1184657; • NOAA Moored Autonomous pCO2 (MAPCO2) Buoy data, doi:10.3334/CDIAC/OTG.TSM{\_}LAPUSH{\_}125W{\_}48N; doi:10.3334/CDIAC/OTG.TSM{\_}WA{\_}125W{\_}47N; doi:10.3334/CDIAC/OTG.TSM{\_}DABOB{\_}122W{\_}478N; doi:10.3334/CDIAC/OTG.TSM{\_}TWANOH{\_}123W{\_}47N; • UW Oceanic Remote Chemical/Optical Analyzer Buoy data, doi:10.5281/zenodo.1184657; • NOAA Pacific Coast Ocean Observing System cruise data, doi:10.5281/zenodo.1184657.},
author = {Fassbender, Andrea J. and Alin, Simone R. and Feely, Richard A. and Sutton, Adrienne J. and Newton, Jan A. and Krembs, Christopher and Bos, Julia and Keyzers, Mya and Devol, Allan and Ruef, Wendi and Pelletier, Greg},
doi = {10.5194/essd-10-1367-2018},
issn = {18663516},
journal = {Earth System Science Data},
number = {3},
pages = {1367--1401},
title = {{Seasonal carbonate chemistry variability in marine surface waters of the US Pacific Northwest}},
volume = {10},
year = {2018}
}
@article{Fatichi2019,
abstract = {Contents Summary I. Introduction II. Discrepancy in predicting the effects of rising [CO2] on the terrestrial C sink III. Carbon and nutrient storage in plants and its modelling IV. Modelling the source and the sink: a plant perspective V. Plant‐scale water and Carbon flux models VI. Challenges for the future Acknowledgements Authors contributions References The increase in atmospheric CO2 in the future is one of the most certain projections in environmental sciences. Understanding whether vegetation carbon assimilation, growth, and changes in vegetation carbon stocks are affected by higher atmospheric CO2 and translating this understanding in mechanistic vegetation models is of utmost importance. This is highlighted by inconsistencies between global‐scale studies that attribute terrestrial carbon sinks to CO2 stimulation of gross and net primary production on the one hand, and forest inventories, tree‐scale studies, and plant physiological evidence showing a much less pronounced CO2 fertilization effect on the other hand. Here, we review how plant carbon sources and sinks are currently described in terrestrial biosphere models. We highlight an uneven representation of complexity between the modelling of photosynthesis and other processes, such as plant respiration, direct carbon sinks, and carbon allocation, largely driven by available observations. Despite a general lack of data on carbon sink dynamics to drive model improvements, ways forward toward a mechanistic representation of plant carbon sinks are discussed, leveraging on results obtained from plant‐scale models and on observations geared toward model developments.},
author = {Fatichi, Simone and Pappas, Christoforos and Zscheischler, Jakob and Leuzinger, Sebastian},
doi = {10.1111/nph.15451},
issn = {0028646X},
journal = {New Phytologist},
keywords = {carbon cycle,ecosystem modelling,nonstructural carbohydrates,photosynthesis,plant growth,respiration},
month = {jan},
number = {2},
pages = {652--668},
title = {{Modelling carbon sources and sinks in terrestrial vegetation}},
url = {http://doi.wiley.com/10.1111/nph.15451},
volume = {221},
year = {2019}
}
@article{Fatichi2016,
abstract = {Increasing concentrations of atmospheric carbon dioxide are expected to affect carbon assimilation and evapotranspiration (ET), ultimately driving changes in plant growth, hydrology, and the global carbon balance. Direct leaf biochemical effects have been widely investigated, whereas indirect effects, although documented, elude explicit quantification in experiments. Here, we used a mechanistic model to investigate the relative contributions of direct (through carbon assimilation) and indirect (via soil moisture savings due to stomatal closure, and changes in leaf area index) effects of elevated CO2 across a variety of ecosystems. We specifically determinedwhich ecosystems and climatic conditions maximize the indirect effects of elevated CO2. The simulations suggest that the indirect effects of elevated CO2 on net primary productivity are large and variable, ranging from less than 10{\%} to more than 100{\%} of the size of direct effects. For ET, indirect effects were, on average, 65{\%} of the size of direct effects. Indirect effects tended to be considerably larger in water-limited ecosystems. As a consequence, the total CO2 effect had a significant, inverse relationship with the wetness index and was directly related to vapor pressure deficit. These results have major implications for our understanding of the CO2 response of ecosystems and for global projections of CO2 fertilization, because, although direct effects are typically understood and easily reproducible in models, simulations of indirect effects are far more challenging and difficult to constrain. Our findings also provide an explanation for the discrepancies between experiments in the total CO2 effect on net primary productivity.},
author = {Fatichi, Simone and Leuzinger, Sebastian and Paschalis, Athanasios and {Adam Langley}, J. and Barraclough, Alicia Donnellan and Hovenden, Mark J.},
doi = {10.1073/pnas.1605036113},
issn = {10916490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Carbon dioxide,Evapotranspiration,FACE,Modeling,Soil moisture},
number = {45},
pages = {12757--12762},
title = {{Partitioning direct and indirect effects reveals the response of water-limited ecosystems to elevated CO2}},
volume = {113},
year = {2016}
}
@article{Fay2014a,
abstract = {{\textless}p{\textgreater}Abstract. Large-scale studies of ocean biogeochemistry and carbon cycling have often partitioned the ocean into regions along lines of latitude and longitude despite the fact that spatially more complex boundaries would be closer to the true biogeography of the ocean. Herein, we define 17 open-ocean biomes classified from four observational data sets: sea surface temperature (SST), spring/summer chlorophyll a concentrations (Chl a), ice fraction, and maximum mixed layer depth (maxMLD) on a 1° × 1° grid (available at doi:10.1594/PANGAEA.828650). By considering interannual variability for each input, we create dynamic ocean biome boundaries that shift annually between 1998 and 2010. Additionally we create a core biome map, which includes only the grid cells that do not change biome assignment across the 13 years of the time-varying biomes. These biomes can be used in future studies to distinguish large-scale ocean regions based on biogeochemical function.{\textless}/p{\textgreater}},
author = {Fay, A. R. and McKinley, G. A.},
doi = {10.5194/essd-6-273-2014},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {aug},
number = {2},
pages = {273--284},
title = {{Global open-ocean biomes: mean and temporal variability}},
url = {https://www.earth-syst-sci-data.net/6/273/2014/},
volume = {6},
year = {2014}
}
@article{Feely2016,
abstract = {Abstract The continental shelf region off the west coast of North America is seasonally exposed to water with a low aragonite saturation state by coastal upwelling of CO2-rich waters. To date, the spatial and temporal distribution of anthropogenic CO2 (Canth) within the CO2-rich waters is largely unknown. Here we adapt the multiple linear regression approach to utilize the GO-SHIP Repeat Hydrography data from the northeast Pacific to establish an annually updated relationship between Canth and potential density. This relationship was then used with the NOAA Ocean Acidification Program West Coast Ocean Acidification (WCOA) cruise data sets from 2007, 2011, 2012, and 2013 to determine the spatial variations of Canth in the upwelled water. Our results show large spatial differences in Canth in surface waters along the coast, with the lowest values (37–55 $\mu$mol kg−1) in strong upwelling regions off southern Oregon and northern California and higher values (51–63 $\mu$mol kg−1) to the north and south of this region. Coastal dissolved inorganic carbon concentrations are also elevated due to a natural remineralized component (Cbio), which represents carbon accumulated through net respiration in the seawater that has not yet degassed to the atmosphere. Average surface Canth is almost twice the surface remineralized component. In contrast, Canth is only about one third and one fifth of the remineralized component at 50 m and 100 m depth, respectively. Uptake of Canth has caused the aragonite saturation horizon to shoal by approximately 30–50 m since the preindustrial period so that undersaturated waters are well within the regions of the continental shelf that affect the shell dissolution of living pteropods. Our data show that the most severe biological impacts occur in the nearshore waters, where corrosive waters are closest to the surface. Since the pre-industrial times, pteropod shell dissolution has, on average, increased approximately 19–26{\%} in both nearshore and offshore waters.},
author = {Feely, Richard A and Alin, Simone R and Carter, Brendan and Bednar{\v{s}}ek, Nina and Hales, Burke and Chan, Francis and Hill, Tessa M and Gaylord, Brian and Sanford, Eric and Byrne, Robert H and Sabine, Christopher L and Greeley, Dana and Juranek, Lauren},
doi = {10.1016/j.ecss.2016.08.043},
issn = {02727714},
journal = {Estuarine, Coastal and Shelf Science},
keywords = {Anthropogenic CO2,California current large marine ecosystem,Ocean acidification,Pteropod dissolution,Upwelling},
month = {dec},
pages = {260--270},
title = {{Chemical and biological impacts of ocean acidification along the west coast of North America}},
url = {http://www.sciencedirect.com/science/article/pii/S0272771416302980},
volume = {183},
year = {2016}
}
@article{ISI:000279860800002,
abstract = {Puget Sound is a large estuary complex in the U.S. Pacific Northwest that is home to a diverse and economically important ecosystem threatened by anthropogenic impacts associated with climate change, urbanization, and ocean acidification. While ocean acidification has been studied in oceanic waters, little is known regarding its status in estuaries. Anthropogenically acidified coastal waters upwelling along the western North American continental margin can enter Puget Sound through the Strait of Juan de Fuca. In order to study the combined effects of ocean acidification and other natural and anthropogenic processes on Puget Sound waters, we made the first inorganic carbon measurements in this estuary on two survey cruises in February and August of 2008. Observed pH and aragonite saturation state values in surface and subsurface waters were substantially lower in parts of Puget Sound than would be expected from anthropogenic carbon dioxide (CO(2)) uptake alone. We estimate that ocean acidification can account for 24-49{\%} of the pH decrease in the deep waters of the Hood Canal sub-basin of Puget Sound relative to estimated pre-industrial values. The remaining change in pH between when seawater enters the sound and when it reaches this deep basin results from remineralization of organic matter due to natural or anthropogenically stimulated respiration processes within Puget Sound. Over time, however, the relative impact of ocean acidification could increase significantly, accounting for 49-82{\%} of the pH decrease in subsurface waters for a doubling of atmospheric CO(2). These changes may have profound impacts on the Puget Sound ecosystem over the next several decades. These estimates suggest that the role ocean acidification will play in estuaries may be different from the open ocean. Published by Elsevier Ltd.},
author = {Feely, Richard A and Alin, Simone R and Newton, Jan and Sabine, Christopher L and Warner, Mark and Devol, Allan and Krembs, Christopher and Maloy, Carol},
doi = {10.1016/j.ecss.2010.05.004},
issn = {02727714},
journal = {Estuarine, Coastal and Shelf Science},
keywords = {acidification,carbonate,estuary,pH,saturation},
month = {aug},
number = {4},
pages = {442--449},
title = {{The combined effects of ocean acidification, mixing, and respiration on pH and carbonate saturation in an urbanized estuary}},
url = {http://linkinghub.elsevier.com/retrieve/pii/S027277141000185X https://linkinghub.elsevier.com/retrieve/pii/S027277141000185X},
volume = {88},
year = {2010}
}
@article{Feely2008a,
abstract = {The absorption of atmospheric carbon dioxide (CO2) into the ocean lowers the pH of the waters. This so-called ocean acidification could have important consequences for marine ecosystems. To better understand the extent of this ocean acidification in coastal waters, we conducted hydrographic surveys along the continental shelf of western North America from central Canada to northern Mexico. We observed seawater that is undersaturated with respect to aragonite upwelling onto large portions of the continental shelf, reaching depths of ∼40 to 120 meters along most transect lines and all the way to the surface on one transect off northern California. Although seasonal upwelling of the undersaturated waters onto the shelf is a natural phenomenon in this region, the ocean uptake of anthropogenic CO2 has increased the areal extent of the affected area.},
annote = {From Duplicate 1 (Evidence for Upwelling of Corrosive "Acidified" Water onto the Continental Shelf - Feely, Richard A; Sabine, Christopher L; Hernandez-Ayon, J Martin; Ianson, Debby; Hales, Burke)

10.1126/science.1155676},
author = {Feely, Richard A and Sabine, Christopher L and Hernandez-Ayon, J Martin and Ianson, Debby and Hales, Burke},
doi = {10.1126/science.1155676},
issn = {0036-8075},
journal = {Science},
month = {jun},
number = {5882},
pages = {1490--1492},
title = {{Evidence for upwelling of corrosive “acidified” water onto the continental shelf}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1155676},
volume = {320},
year = {2008}
}
@article{Feely2012,
abstract = {Based on measurements from the WOCE/JGOFS global CO2 survey, the CLIVAR/CO2 Repeat Hydrography Program and the Canadian Line P survey, we have observed an average decrease of 0.34{\%} yr?1 in the saturation state of surface seawater in the Pacific Ocean with respect to aragonite and calcite. The upward migrations of the aragonite and calcite saturation horizons, averaging about 1 to 2 m yr?1, are the direct result of the uptake of anthropogenic CO2 by the oceans and regional changes in circulation and biogeochemical processes. The shoaling of the saturation horizon is regionally variable, with more rapid shoaling in the South Pacific where there is a larger uptake of anthropogenic CO2. In some locations, particularly in the North Pacific Subtropical Gyre and in the California Current, the decadal changes in circulation can be the dominant factor in controlling the migration of the saturation horizon. If CO2 emissions continue as projected over the rest of this century, the resulting changes in the marine carbonate system would mean that many coral reef systems in the Pacific would no longer be able to sustain a sufficiently high rate of calcification to maintain the viability of these ecosystems as a whole, and these changes perhaps could seriously impact the thousands of marine species that depend on them for survival.},
annote = {From Duplicate 2 (Decadal changes in the aragonite and calcite saturation state of the Pacific Ocean - Feely, Richard A; Sabine, Christopher L; Byrne, Robert H; Millero, Frank J; Dickson, Andrew G; Wanninkhof, Rik; Murata, Akihiko; Miller, Lisa A; Greeley, Dana)

https://doi.org/10.1029/2011GB004157},
author = {Feely, Richard A and Sabine, Christopher L and Byrne, Robert H and Millero, Frank J and Dickson, Andrew G and Wanninkhof, Rik and Murata, Akihiko and Miller, Lisa A and Greeley, Dana},
doi = {10.1029/2011GB004157},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {Pacific Ocean,acidification,aragonite,calcite,carbon dioxide,saturation state},
month = {sep},
number = {3},
pages = {2011GB004157},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Decadal changes in the aragonite and calcite saturation state of the Pacific Ocean}},
url = {https://doi.org/10.1029/2011GB004157 https://onlinelibrary.wiley.com/doi/abs/10.1029/2011GB004157},
volume = {26},
year = {2012}
}
@article{Feely2018,
abstract = {Inorganic carbon chemistry data from the surface and subsurface waters of the West Coast of North America have been compared with similar data from the northern Gulf of Mexico to demonstrate how future changes in CO2 emissions will affect chemical changes in coastal waters affected by respiration-induced hypoxia ([O2] ≤ {\~{}} 60µmolkg−1). In surface waters, the percentage change in the carbon parameters due to increasing CO2 emissions are very similar for both regions even though the absolute decrease in aragonite saturation is much higher in the warmer waters of the Gulf of Mexico. However, in subsurface waters the changes are enhanced due to differences in the initial oxygen concentration and the changes in the buffer capacity (i.e., increasing Revelle Factor) with increasing respiration from the oxidation of organic matter, with the largest impacts on pH and CO2 partial pressure (pCO2) occurring in the colder West Coast waters. As anthropogenic CO2 concentrations begin to build up in subsurface waters, increased atmospheric CO2 will expose organisms to hypercapnic conditions (pCO2 {\textgreater}1000 µatm) within subsurface depths. Since the maintenance of the extracellular pH appears as the first line of defense against external stresses, many biological response studies have been focused on pCO2-induced hypercapnia. The extent of subsurface exposure will occur sooner and be more widespread in colder waters due to their capacity to hold more dissolved oxygen and the accompanying weaker acid-base buffer capacity. Under present conditions, organisms in the West Coast are exposed to hypercapnic conditions when oxygen concentrations are near 100µmolkg−1 but will experience hypercapnia at oxygen concentrations of 260µmolkg−1 by year 2100 under the highest elevated-CO2 conditions. Hypercapnia does not occur at present in the Gulf of Mexico but will occur at oxygen concentrations of 170µmolkg−1 by the end of the century under similar conditions. The aragonite saturation horizon is currently above the hypoxic zone in the West Coast. With increasing atmospheric CO2, it is expected to shoal up close to surface waters under the IPCC Representative Concentration Pathway (RCP) 8.5 in West Coast waters, while aragonite saturation state will exhibit steeper gradients in the Gulf of Mexico. This study demonstrates how different biological thresholds (e.g., hypoxia, CaCO3 undersaturation, hypercapnia) will vary asymmetrically because of local initial conditions that are affected differently with increasing atmospheric CO2. The direction of change in amplitude of hypercapnia will be similar in both ecosystems, exposing both biological communities from the West Coast and Gulf of Mexico to intensification of stressful conditions. However, the region of lower Revelle factors (i.e., the Gulf of Mexico), currently provides an adequate refuge habitat that might no longer be the case under the most severe RCP scenarios.},
author = {Feely, Richard A and Okazaki, Remy R and Cai, Wei-Jun and Bednar{\v{s}}ek, Nina and Alin, Simone R and Byrne, Robert H and Fassbender, Andrea},
doi = {10.1016/j.csr.2017.11.002},
issn = {02784343},
journal = {Continental Shelf Research},
keywords = {CaCO undersaturation,Hypercapnia,Hypoxia,Ocean acidification},
month = {jan},
pages = {50--60},
title = {{The combined effects of acidification and hypoxia on pH and aragonite saturation in the coastal waters of the California current ecosystem and the northern Gulf of Mexico}},
url = {http://www.sciencedirect.com/science/article/pii/S0278434317303643 https://linkinghub.elsevier.com/retrieve/pii/S0278434317303643},
volume = {152},
year = {2018}
}
@article{Feely2009,
author = {Feely, Richard A and Doney, Scott and Cooley, Sarah},
doi = {10.5670/oceanog.2009.95},
issn = {10428275},
journal = {Oceanography},
month = {dec},
number = {4},
pages = {36--47},
title = {{Ocean Acidification: Present Conditions and Future Changes in a High-CO2 World}},
url = {https://tos.org/oceanography/article/ocean-acidification-present-conditions-and-future-changes-in-a-high-co2-wor},
volume = {22},
year = {2009}
}
@article{Feng2020,
author = {Feng, Ellias Yuming and Su, Bei and Oschlies, Andreas},
doi = {10.1029/2020GL088263},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {aug},
number = {16},
pages = {e2020GL088263},
title = {{Geoengineered Ocean Vertical Water Exchange Can Accelerate Global Deoxygenation}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020GL088263 https://onlinelibrary.wiley.com/doi/10.1029/2020GL088263},
volume = {47},
year = {2020}
}
@article{Fennel2019c,
author = {Fennel, Katja and Alin, Simone and Barbero, Leticia and Evans, Wiley and Bourgeois, Timoth{\'{e}}e and Cooley, Sarah and Dunne, John and Feely, Richard A. and Hernandez-Ayon, Jose Martin and Hu, Xinping and Lohrenz, Steven and Muller-Karger, Frank and Najjar, Raymond and Robbins, Lisa and Shadwick, Elizabeth and Siedlecki, Samantha and Steiner, Nadja and Sutton, Adrienne and Turk, Daniela and Vlahos, Penny and Wang, Zhaohui Aleck},
doi = {10.5194/bg-16-1281-2019},
issn = {1726-4189},
journal = {Biogeosciences},
month = {mar},
number = {6},
pages = {1281--1304},
title = {{Carbon cycling in the North American coastal ocean: a synthesis}},
url = {https://www.biogeosciences.net/16/1281/2019/},
volume = {16},
year = {2019}
}
@article{Fennel2019,
abstract = {Aquatic environments experiencing low-oxygen conditions have been described as hypoxic, suboxic, or anoxic zones; oxygen minimum zones; and, in the popular media, the misnomer “dead zones.” This review aims to elucidate important aspects underlying oxygen depletion in diverse coastal systems and provides a synthesis of general relationships between hypoxia and its controlling factors. After presenting a generic overview of the first-order processes, we review system-specific characteristics for selected estuaries where adjacent human settlements contribute to high nutrient loads, river-dominated shelves that receive large inputs of fresh water and anthropogenic nutrients, and upwelling regions where a supply of nutrient-rich, low-oxygen waters generates oxygen minimum zones without direct anthropogenic influence. We propose a nondimensional number that relates the hypoxia timescale and water residence time to guide the cross-system comparison. Our analysis reveals the basic principles underlying hypoxia generation in coastal systems and provides a framework for discussing future changes.},
annote = {doi: 10.1146/annurev-marine-010318-095138},
author = {Fennel, Katja and Testa, Jeremy M},
doi = {10.1146/annurev-marine-010318-095138},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {105--130},
publisher = {Annual Reviews},
title = {{Biogeochemical controls on coastal hypoxia}},
url = {https://doi.org/10.1146/annurev-marine-010318-095138 https://www.annualreviews.org/doi/10.1146/annurev-marine-010318-095138},
volume = {11},
year = {2019}
}
@article{Fernandez-Martinez2019,
abstract = {Elevated CO 2 concentrations increase photosynthesis and, potentially, net ecosystem production (NEP), meaning a greater CO 2 uptake. Climate, nutrients and ecosystem structure, however, influence the effect of increasing CO 2 . Here we analysed global NEP from MACC-II and Jena CarboScope atmospheric inversions and ten dynamic global vegetation models (TRENDY), using statistical models to attribute the trends in NEP to its potential drivers: CO 2 , climatic variables and land-use change. We found that an increased CO 2 was consistently associated with an increased NEP (1995–2014). Conversely, increased temperatures were negatively associated with NEP. Using the two atmospheric inversions and TRENDY, the estimated global sensitivities for CO 2 were 6.0 ± 0.1, 8.1 ± 0.3 and 3.1 ± 0.1 PgC per 100 ppm ({\~{}}1 °C increase), and −0.5 ± 0.2, −0.9 ± 0.4 and −1.1 ± 0.1 PgC °C −1 for temperature. These results indicate a positive CO 2 effect on terrestrial C sinks that is constrained by climate warming.},
author = {Fern{\'{a}}ndez-Mart{\'{i}}nez, M. and Sardans, J. and Chevallier, F. and Ciais, P. and Obersteiner, M. and Vicca, S. and Canadell, J. G. and Bastos, A. and Friedlingstein, P. and Sitch, S. and Piao, S. L. and Janssens, I. A. and Pe{\~{n}}uelas, J.},
doi = {10.1038/s41558-018-0367-7},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jan},
number = {1},
pages = {73--79},
title = {{Global trends in carbon sinks and their relationships with CO2 and temperature}},
url = {http://www.nature.com/articles/s41558-018-0367-7},
volume = {9},
year = {2019}
}
@article{Ferrari2014,
abstract = {In the modern climate, the ocean below 2 km is mainly filled by waters sinking into the abyss around Antarctica and in the North Atlantic. Paleoproxies indicate that waters of North Atlantic origin were instead absent below 2 km at the Last Glacial Maximum, resulting in an expansion of the volume occupied by Antarctic origin waters. In this study we show that this rearrangement of deep water masses is dynamically linked to the expansion of summer sea ice around Antarctica. A simple theory further suggests that these deep waters only came to the surface under sea ice, which insulated them from atmospheric forcing, and were weakly mixed with overlying waters, thus being able to store carbon for long times. This unappreciated link between the expansion of sea ice and the appearance of a voluminous and insulated water mass may help quantify the ocean's role in regulating atmospheric carbon dioxide on glacial-interglacial timescales. Previous studies pointed to many independent changes in ocean physics to account for the observed swings in atmospheric carbon dioxide. Here it is shown that many of these changes are dynamically linked and therefore must co-occur.},
archivePrefix = {arXiv},
arxivId = {arXiv:1408.1149},
author = {Ferrari, R. and Jansen, M. F. and Adkins, J. F. and Burke, A. and Stewart, A. L. and Thompson, A. F.},
doi = {10.1073/pnas.1323922111},
eprint = {arXiv:1408.1149},
isbn = {0711232105},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {jun},
number = {24},
pages = {8753--8758},
pmid = {24889624},
title = {{Antarctic sea ice control on ocean circulation in present and glacial climates}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1323922111},
volume = {111},
year = {2014}
}
@article{Ferretti2005,
abstract = {We report a 2000-year Antarctic ice-core record of stable carbon isotope measurements in atmospheric methane (delta13CH4). Large delta13CH4 variations indicate that the methane budget varied unexpectedly during the late preindustrial Holocene (circa 0 to 1700 A.D.). During the first thousand years (0 to 1000 A.D.), delta13CH4 was at least 2 per mil enriched compared to expected values, and during the following 700 years, an about 2 per mil depletion occurred. Our modeled methane source partitioning implies that biomass burning emissions were high from 0 to 1000 A.D. but reduced by almost approximately 40{\%} over the next 700 years. We suggest that both human activities and natural climate change influenced preindustrial biomass burning emissions and that these emissions have been previously understated in late preindustrial Holocene methane budget research.},
author = {Ferretti, D F and Miller, J. B. and White, J. W. C. and Etheridge, D. M. and Lassey, K. R. and Lowe, D. C. and Meure, C. M. MacFarling and Dreier, M. F. and Trudinger, C. M. and van Ommen, T. D. and Langenfelds, R. L.},
doi = {10.1126/science.1115193},
issn = {0036-8075},
journal = {Science},
month = {sep},
number = {5741},
pages = {1714--1717},
pmid = {16151008},
publisher = {American Association for the Advancement of Science},
title = {{Unexpected Changes to the Global Methane Budget over the Past 2000 Years}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.1115193 https://www.science.org/doi/10.1126/science.1115193},
volume = {309},
year = {2005}
}
@article{Field9204,
abstract = {The 2015 fire season and related smoke pollution in Indonesia was more severe than the major 2006 episode, making it the most severe season observed by the NASA Earth Observing System satellites that go back to the early 2000s, namely active fire detections from the Terra and Aqua Moderate Resolution Imaging Spectroradiometers (MODIS), MODIS aerosol optical depth, Terra Measurement of Pollution in the Troposphere (MOPITT) carbon monoxide (CO), Aqua Atmospheric Infrared Sounder (AIRS) CO, Aura Ozone Monitoring Instrument (OMI) aerosol index, and Aura Microwave Limb Sounder (MLS) CO. The MLS CO in the upper troposphere showed a plume of pollution stretching from East Africa to the western Pacific Ocean that persisted for 2 mo. Longer-term records of airport visibility in Sumatra and Kalimantan show that 2015 ranked after 1997 and alongside 1991 and 1994 as among the worst episodes on record. Analysis of yearly dry season rainfall from the Tropical Rainfall Measurement Mission (TRMM) and rain gauges shows that, due to the continued use of fire to clear and prepare land on degraded peat, the Indonesian fire environment continues to have nonlinear sensitivity to dry conditions during prolonged periods with less than 4 mm/d of precipitation, and this sensitivity appears to have increased over Kalimantan. Without significant reforms in land use and the adoption of early warning triggers tied to precipitation forecasts, these intense fire episodes will reoccur during future droughts, usually associated with El Ni{\~{n}}o events.},
author = {Field, Robert D and van der Werf, Guido R and Fanin, Thierry and Fetzer, Eric J and Fuller, Ryan and Jethva, Hiren and Levy, Robert and Livesey, Nathaniel J and Luo, Ming and Torres, Omar and Worden, Helen M},
doi = {10.1073/pnas.1524888113},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {aug},
number = {33},
pages = {9204--9209},
publisher = {National Academy of Sciences},
title = {{Indonesian fire activity and smoke pollution in 2015 show persistent nonlinear sensitivity to El Ni{\~{n}}o-induced drought}},
url = {http://www.pnas.org/content/113/33/9204 http://www.pnas.org/lookup/doi/10.1073/pnas.1524888113},
volume = {113},
year = {2016}
}
@article{Finzi2007,
abstract = {Forest ecosystems are important sinks for rising concentrations of atmospheric CO2. In previous research, we showed that net primary production (NPP) increased by 23 ± 2{\%} when four experimental forests were grown under atmospheric concentrations of CO2 predicted for the latter half of this century. Because nitrogen (N) availability commonly limits forest productivity, some combination of increased N uptake from the soil and more efficient use of the N already assimilated by trees is necessary to sustain the high rates of forest NPP under free-air CO2 enrichment (FACE). In this study, experimental evidence demonstrates that the uptake of N increased under elevated CO2 at the Rhinelander, Duke, and Oak Ridge National Laboratory FACE sites, yet fertilization studies at the Duke and Oak Ridge National Laboratory FACE sites showed that tree growth and forest NPP were strongly limited by N availability. By contrast, nitrogen-use efficiency increased under elevated CO2 at the POP-EUROFACE site, where fertilization studies showed that N was not limiting to tree growth. Some combination of increasing fine root production, increased rates of soil organic matter decomposition, and increased allocation of carbon (C) to mycorrhizal fungi is likely to account for greater N uptake under elevated CO2. Regardless of the specific mechanism, this analysis shows that the larger quantities of C entering the below-ground system under elevated CO2 result in greater N uptake, even in N-limited ecosystems. Biogeochemical models must be reformulated to allow C transfers below ground that result in additional N uptake under elevated CO2.},
author = {Finzi, A. C. and Norby, R. J. and Calfapietra, C. and Gallet-Budynek, A. and Gielen, B. and Holmes, W. E. and Hoosbeek, M. R. and Iversen, C. M. and Jackson, R. B. and Kubiske, M. E. and Ledford, J. and Liberloo, M. and Oren, R. and Polle, A. and Pritchard, S. and Zak, D. R. and Schlesinger, W. H. and Ceulemans, R.},
doi = {10.1073/pnas.0706518104},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {aug},
number = {35},
pages = {14014--14019},
title = {{Increases in nitrogen uptake rather than nitrogen-use efficiency support higher rates of temperate forest productivity under elevated CO2}},
url = {http://www.pnas.org/content/104/35/14014 http://www.pnas.org/cgi/doi/10.1073/pnas.0706518104},
volume = {104},
year = {2007}
}
@article{Fischer2019,
abstract = {There is an urgent need to develop agricultural methods that balance water supply and demand while at the same time improve resilience to climate variability. A promising instrument to address this need is biochar - a charcoal made from pyrolyzed organic material. However, it is often unclear how, if at all, biochar improves soil water availability, plant water consumption rates and crop yields. To address this question, we synthesized literature-derived observational data and evaluated the effects of biochar on evapotranspiration using a minimal soil water balance model. Results from the model were interpreted in the Budyko framework to assess how climatic conditions mediate the impacts of biochar on water fluxes. Our analysis of literature-derived observational data showed that while biochar addition generally increases the soil water holding capacity, it can have variable impacts on soil water retention relative to control conditions. Our modelling demonstrated that biochar increases long-term evapotranspiration rates, and therefore plant water availability, by increasing soil water retention capacity - especially in water-limited regions. Biochar amendments generally increased crop yields (75{\%} of the compiled studies) and, in several cases (35{\%} of the compiled studies), biochar amendments simultaneously increased crop yield and water use efficiencies. Hence, while biochar amendments are promising, the potential for variable impact highlights the need for targeted research on how biochar affects the soil-plant-water cycle.},
author = {Fischer, Benjamin M C and Manzoni, Stefano and Morillas, Laura and Garcia, Monica and Johnson, Mark S and Lyon, Steve W},
doi = {10.1016/j.scitotenv.2018.11.312},
issn = {1879-1026 (Electronic)},
journal = {Science of The Total Environment},
keywords = {Agricultural,Agriculture,Charcoal,Crops,Models,Plant Transpiration,Soil,Theoretical,Tropical Climate,Water,chemistry,methods,physiology},
language = {eng},
month = {mar},
pages = {853--862},
pmid = {30677950},
title = {{Improving agricultural water use efficiency with biochar – A synthesis of biochar effects on water storage and fluxes across scales}},
volume = {657},
year = {2019}
}
@article{Fischer2019a,
author = {Fischer, Hubertus and Schmitt, Jochen and Bock, Michael and Seth, Barbara and Joos, Fortunat and Spahni, Renato and Lienert, Sebastian and Battaglia, Gianna and Stocker, Benjamin D. and Schilt, Adrian and Brook, Edward J.},
doi = {10.5194/bg-16-3997-2019},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {20},
pages = {3997--4021},
title = {{N2O changes from the Last Glacial Maximum to the preindustrial – Part 1: Quantitative reconstruction of terrestrial and marine emissions using N2O stable isotopes in ice cores}},
url = {https://bg.copernicus.org/articles/16/3997/2019/},
volume = {16},
year = {2019}
}
@article{doi:10.1111/gcb.13910,
abstract = {Abstract Numerous current efforts seek to improve the representation of ecosystem ecology and vegetation demographic processes within Earth System Models (ESMs). These developments are widely viewed as an important step in developing greater realism in predictions of future ecosystem states and fluxes. Increased realism, however, leads to increased model complexity, with new features raising a suite of ecological questions that require empirical constraints. Here, we review the developments that permit the representation of plant demographics in ESMs, and identify issues raised by these developments that highlight important gaps in ecological understanding. These issues inevitably translate into uncertainty in model projections but also allow models to be applied to new processes and questions concerning the dynamics of real-world ecosystems. We argue that stronger and more innovative connections to data, across the range of scales considered, are required to address these gaps in understanding. The development of first-generation land surface models as a unifying framework for ecophysiological understanding stimulated much research into plant physiological traits and gas exchange. Constraining predictions at ecologically relevant spatial and temporal scales will require a similar investment of effort and intensified inter-disciplinary communication.},
author = {Fisher, Rosie A and Koven, Charles D and Anderegg, William R L and Christoffersen, Bradley O and Dietze, Michael C and Farrior, Caroline E and Holm, Jennifer A and Hurtt, George C and Knox, Ryan G and Lawrence, Peter J and Lichstein, Jeremy W and Longo, Marcos and Matheny, Ashley M and Medvigy, David and Muller-Landau, Helene C and Powell, Thomas L and Serbin, Shawn P and Sato, Hisashi and Shuman, Jacquelyn K and Smith, Benjamin and Trugman, Anna T and Viskari, Toni and Verbeeck, Hans and Weng, Ensheng and Xu, Chonggang and Xu, Xiangtao and Zhang, Tao and Moorcroft, Paul R},
doi = {10.1111/gcb.13910},
journal = {Global Change Biology},
keywords = {Earth System Model,carbon cycle,demographics,dynamic global vegetation models,ecosystem,vegetation},
number = {1},
pages = {35--54},
title = {{Vegetation demographics in Earth System Models: A review of progress and priorities}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13910},
volume = {24},
year = {2018}
}
@article{Flach2021,
abstract = {Drought and heat events affect the uptake and sequestration of carbon in terrestrial ecosystems. Factors such as the duration, timing, and intensity of extreme events influence the magnitude of impacts on ecosystem processes such as gross primary production (GPP), i.e., the ecosystem uptake of CO2. Preceding soil moisture depletion may exacerbate these impacts. However, some vegetation types may be more resilient to climate extremes than others. This effect is insufficiently understood at the global scale and is the focus of this study. Using a global upscaled product of GPP that scales up in situ land CO2 flux observations with global satellite remote sensing, we study the impact of climate extremes at the global scale. We find that GPP in grasslands and agricultural areas is generally reduced during heat and drought events. However, we also find that forests, if considered globally, appear in general to not be particularly sensitive to droughts and heat events that occurred during the analyzed period or even show increased GPP values during these events. On the one hand, normal-to-increased GPP values are in many cases plausible, e.g., when conditions prior to the event have been particularly positive. On the other hand, however, normal-to-increased GPP values in forests may also reflect a lack of sensitivity in current remote-sensing-derived GPP products to the effects of droughts and heatwaves. The overall picture calls for a differentiated consideration of different land cover types in the assessments of risks of climate extremes for ecosystem functioning.},
author = {Flach, Milan and Brenning, Alexander and Gans, Fabian and Reichstein, Markus and Sippel, Sebastian and Mahecha, Miguel D.},
doi = {10.5194/bg-18-39-2021},
issn = {17264189},
journal = {Biogeosciences},
number = {1},
pages = {39--53},
title = {{Vegetation modulates the impact of climate extremes on gross primary production}},
volume = {18},
year = {2021}
}
@article{Fleischer2019,
abstract = {Global terrestrial models currently predict that the Amazon rainforest will continue to act as a carbon sink in the future, primarily owing to the rising atmospheric carbon dioxide (CO2) concentration. Soil phosphorus impoverishment in parts of the Amazon basin largely controls its functioning, but the role of phosphorus availability has not been considered in global model ensembles—for example, during the Fifth Climate Model Intercomparison Project. Here we simulate the planned free-air CO2 enrichment experiment AmazonFACE with an ensemble of 14 terrestrial ecosystem models. We show that phosphorus availability reduces the projected CO2-induced biomass carbon growth by about 50{\%} to 79 ± 63 g C m−2 yr−1 over 15 years compared to estimates from carbon and carbon–nitrogen models. Our results suggest that the resilience of the region to climate change may be much less than previously assumed. Variation in the biomass carbon response among the phosphorus-enabled models is considerable, ranging from 5 to 140 g C m−2 yr−1, owing to the contrasting plant phosphorus use and acquisition strategies considered among the models. The Amazon forest response thus depends on the interactions and relative contributions of the phosphorus acquisition and use strategies across individuals, and to what extent these processes can be upregulated under elevated CO2.},
author = {Fleischer, Katrin and Rammig, Anja and {De Kauwe}, Martin G and Walker, Anthony P and Domingues, Tomas F and Fuchslueger, Lucia and Garcia, Sabrina and Goll, Daniel S and Grandis, Adriana and Jiang, Mingkai and Haverd, Vanessa and Hofhansl, Florian and Holm, Jennifer A and Kruijt, Bart and Leung, Felix and Medlyn, Belinda E and Mercado, Lina M and Norby, Richard J and Pak, Bernard and von Randow, Celso and Quesada, Carlos A and Schaap, Karst J and Valverde-Barrantes, Oscar J and Wang, Ying-Ping and Yang, Xiaojuan and Zaehle, S{\"{o}}nke and Zhu, Qing and Lapola, David M},
doi = {10.1038/s41561-019-0404-9},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {9},
pages = {736--741},
title = {{Amazon forest response to CO2 fertilization dependent on plant phosphorus acquisition}},
url = {https://doi.org/10.1038/s41561-019-0404-9},
volume = {12},
year = {2019}
}
@article{Fleming2011,
abstract = {Abstract. The long-term stratospheric impacts due to emissions of CO2, CH4, N2O, and ozone depleting substances (ODSs) are investigated using an updated version of the Goddard two-dimensional (2-D) model. Perturbation simulations with the ODSs, CO2, CH4, and N2O varied individually are performed to isolate the relative roles of these gases in driving stratospheric changes over the 1850–2100 time period. We also show comparisons with observations and the Goddard Earth Observing System chemistry-climate model simulations for the time period 1960–2100 to illustrate that the 2-D model captures the basic processes responsible for long-term stratospheric change. The ODSs, CO2, CH4, and N2O impact ozone via several mechanisms. ODS and N2O loading decrease stratospheric ozone via the increases in atmospheric halogen and odd nitrogen species, respectively. CO2 loading impacts ozone by: (1) cooling the stratosphere which increases ozone via the reduction in the ozone chemical loss rates, and (2) accelerating the Brewer-Dobson circulation (BDC) which redistributes ozone in the lower stratosphere. The net result of CO2 loading is an increase in global ozone in the total column and upper stratosphere. CH4 loading impacts ozone by: (1) increasing atmospheric H2O and the odd hydrogen species which decreases ozone via the enhanced HOx-ozone loss rates; (2) increasing the H2O cooling of the middle atmosphere which reduces the ozone chemical loss rates, partially offsetting the enhanced HOx-ozone loss; (3) converting active to reservoir chlorine via the reaction CH4+Cl→HCl+CH3 which leads to more ozone; and (4) increasing the NOx-ozone production in the troposphere. The net result of CH4 loading is an ozone decrease above 40–45 km, and an increase below 40–45 km and in the total column. The 2-D simulations indicate that prior to 1940, the ozone increases due to CO2 and CH4 loading outpace the ozone losses due to increasing N2O and carbon tetrachloride (CCl4) emissions, so that total column and upper stratospheric global ozone reach broad maxima during the 1920s–1930s. This precedes the significant ozone depletion during {\~{}}1960–2050 driven by the ODS loading. During the latter half of the 21st century as ODS emissions diminish, CO2, N2O, and CH4 loading will all have significant impacts on global total ozone based on the Intergovernmental Panel on Climate Change (IPCC) A1B (medium) scenario, with CO2 having the largest individual effect. Sensitivity tests illustrate that due to the strong chemical interaction between methane and chlorine, the CH4 impact on total ozone becomes significantly more positive with larger ODS loading. The model simulations also show that changes in stratospheric temperature, BDC, and age of air during 1850–2100 are controlled mainly by the CO2 and ODS loading. The simulated acceleration of the BDC causes the global average age of air above 22 km to decrease by {\~{}}1 yr from 1860–2100. The photochemical lifetimes of N2O, CFCl3, CF2Cl2, and CCl4 decrease by 11–13 {\%} during 1960–2100 due to the acceleration of the BDC, with much smaller lifetime changes ({\textless}4 {\%}) caused by changes in the photochemical loss rates.},
author = {Fleming, E. L. and Jackman, C. H. and Stolarski, R. S. and Douglass, A. R.},
doi = {10.5194/acp-11-8515-2011},
isbn = {1680-7316},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {aug},
number = {16},
pages = {8515--8541},
pmid = {11166646},
title = {{A model study of the impact of source gas changes on the stratosphere for 1850–2100}},
url = {https://www.atmos-chem-phys.net/11/8515/2011/},
volume = {11},
year = {2011}
}
@article{Flombaum2020,
author = {Flombaum, Pedro and Wang, Wei-Lei and Primeau, Francois W. and Martiny, Adam C.},
doi = {10.1038/s41561-019-0524-2},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {feb},
number = {2},
pages = {116--120},
title = {{Global picophytoplankton niche partitioning predicts overall positive response to ocean warming}},
url = {http://www.nature.com/articles/s41561-019-0524-2},
volume = {13},
year = {2020}
}
@article{Forkel2019c,
abstract = {The apparent decline in the global incidence of fire between 1996 and 2015, as measured by satellite-observations of burned area, has been related to socioeconomic and land use changes. However, recent decades have also seen changes in climate and vegetation that influence fire and fire-enabled vegetation models do not reproduce the apparent decline. Given that the satellite-derived burned area datasets are still relatively short ({\textless}20 years), this raises questions both about the robustness of the apparent decline and what causes it. We use two global satellite-derived burned area datasets and a data-driven fire model to (1) assess the spatio-temporal robustness of the burned area trends and (2) to relate the trends to underlying changes in temperature, precipitation, human population density and vegetation conditions. Although the satellite datasets and simulation all show a decline in global burned area over {\~{}}20 years, the trend is not significant and is strongly affected by the start and end year chosen for trend analysis and the year-to-year variability in burned area. The global and regional trends shown by the two satellite datasets are poorly correlated for the common overlapping period (2001–2015) and the fire model simulates changes in global and regional burned area that lie within the uncertainties of the satellite datasets. The model simulations show that recent increases in temperature would lead to increased burned area but this effect is compensated by increasing wetness or increases in population, both of which lead to declining burned area. Increases in vegetation cover and density associated with recent greening trends lead to increased burned area in fuel-limited regions. Our analyses show that global and regional burned area trends result from the interaction of compensating trends in controls of wildfire at regional scales.},
author = {Forkel, Matthias and Dorigo, Wouter and Lasslop, Gitta and Chuvieco, Emilio and Hantson, Stijn and Heil, Angelika and Teubner, Irene and Thonicke, Kirsten and Harrison, Sandy P},
doi = {10.1088/2515-7620/ab25d2},
issn = {2515-7620},
journal = {Environmental Research Communications},
month = {jun},
number = {5},
pages = {051005},
title = {{Recent global and regional trends in burned area and their compensating environmental controls}},
url = {https://iopscience.iop.org/article/10.1088/2515-7620/ab25d2},
volume = {1},
year = {2019}
}
@article{Forkel2016a,
author = {Forkel, Matthias and Carvalhais, Nuno and Rodenbeck, C. and Keeling, Ralph and Heimann, Martin and Thonicke, Kirsten and Zaehle, S{\"{o}}nke and Reichstein, Markus},
doi = {10.1126/science.aac4971},
isbn = {1095-9203 (Electronic) 0036-8075 (Linking)},
issn = {0036-8075},
journal = {Science},
month = {feb},
number = {6274},
pages = {696--699},
pmid = {26797146},
publisher = {American Association for the Advancement of Science},
title = {{Enhanced seasonal CO2 exchange caused by amplified plant productivity in northern ecosystems}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.aac4971 https://www.sciencemag.org/lookup/doi/10.1126/science.aac4971 http://science.sciencemag.org/content/351/6274/696},
volume = {351},
year = {2016}
}
@article{doi:10.1111/j.1365-2486.2010.02328.x,
abstract = {Abstract The application of calcium- and magnesium-rich materials to soil, known as liming, has long been a foundation of many agro-ecosystems worldwide because of its role in counteracting soil acidity. Although liming contributes to increased rates of respiration from soil thereby potentially reducing soils ability to act as a CO2 sink, the long-term effects of liming on soil organic carbon (Corg) sequestration are largely unknown. Here, using data spanning 129 years of the Park Grass Experiment at Rothamsted (UK), we show net Corg sequestration measured in the 0–23 cm layer at different time intervals since 1876 was 2–20 times greater in limed than in unlimed soils. The main cause of this large Corg accrual was greater biological activity in limed soils, which despite increasing soil respiration rates, led to plant C inputs being processed and incorporated into resistant soil organo-mineral pools. Limed organo-mineral soils showed: (1) greater Corg content for similar plant productivity levels (i.e. hay yields); (2) higher 14C incorporation after 1950s atomic bomb testing and (3) lower C : N ratios than unlimed organo-mineral soils, which also indicate higher microbial processing of plant C. Our results show that greater Corg sequestration in limed soils strongly reduced the global warming potential of long-term liming to permanent grassland suggesting the net contribution of agricultural liming to global warming could be lower than previously estimated. Our study demonstrates that liming might prove to be an effective mitigation strategy, especially because liming applications can be associated with a reduced use of nitrogen fertilizer which is a key cause for increased greenhouse gas emissions from agro-ecosystems.},
author = {Fornara, D A and Steinbeiss, S and McNamara, N P and Gleixner, G and Oakley, S and Poulton, P R and MacDonald, A J and Bardgett, R D},
doi = {10.1111/j.1365-2486.2010.02328.x},
journal = {Global Change Biology},
keywords = {Park Grass Experiment,agro-ecosystems,climate change mitigation,legumes,nitrogen fertilizer,soil density fractionation,soil microbial community},
number = {5},
pages = {1925--1934},
title = {{Increases in soil organic carbon sequestration can reduce the global warming potential of long-term liming to permanent grassland}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2010.02328.x},
volume = {17},
year = {2011}
}
@incollection{IPCC2018,
author = {Forster, P. and Huppmann, D. and Kriegler, E. and Mundaca, L. and Smith, C. and Rogelj, J. and S{\'{e}}f{\'{e}}rian, R.},
booktitle = {Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change,},
chapter = {2},
editor = {Masson-Delmotte, V. and Zhai, P. and P{\"{o}}rtner, H.-O. and Roberts, D. and Skea, J. and Shukla, P.R. and Pirani, A. and Moufouma-Okia, W. and P{\'{e}}an, C. and Pidcock, R. and Connors, S. and Matthews, J.B.R. and Chen, Y. and Zhou, X. and Gomis, M.I. and Lonnoy, E. and Maycock, T. and Tignor, M. and Waterfield, T.},
pages = {2SM: 1--50},
publisher = {In Press},
title = {{Mitigation Pathways Compatible with 1.5°C in the Context of Sustainable Development Supplementary Material}},
url = {https://www.ipcc.ch/sr15/download},
year = {2018}
}
@article{Forster2020,
abstract = {The global response to the COVID-19 pandemic has led to a sudden reduction of both GHG emissions and air pollutants. Here, using national mobility data, we estimate global emission reductions for ten species during the period February to June 2020. We estimate that global NOx emissions declined by as much as 30{\%} in April, contributing a short-term cooling since the start of the year. This cooling trend is offset by {\~{}}20{\%} reduction in global SO2 emissions that weakens the aerosol cooling effect, causing short-term warming. As a result, we estimate that the direct effect of the pandemic-driven response will be negligible, with a cooling of around 0.01 ± 0.005 °C by 2030 compared to a baseline scenario that follows current national policies. In contrast, with an economic recovery tilted towards green stimulus and reductions in fossil fuel investments, it is possible to avoid future warming of 0.3 °C by 2050.},
author = {Forster, Piers M. and Forster, Harriet I. and Evans, Mat J. and Gidden, Matthew J. and Jones, Chris D. and Keller, Christoph A. and Lamboll, Robin D. and Qu{\'{e}}r{\'{e}}, Corinne Le and Rogelj, Joeri and Rosen, Deborah and Schleussner, Carl Friedrich and Richardson, Thomas B. and Smith, Christopher J. and Turnock, Steven T.},
doi = {10.1038/s41558-020-0883-0},
issn = {17586798},
journal = {Nature Climate Change},
number = {10},
pages = {913--919},
publisher = {Springer US},
title = {{Current and future global climate impacts resulting from COVID-19}},
url = {http://dx.doi.org/10.1038/s41558-020-0883-0},
volume = {10},
year = {2020}
}
@article{Forzieri2017a,
abstract = {Changes in vegetation cover associated with the observed greening may affect several biophysical processes, whose net effects on climate are unclear. We analyzed remotely sensed dynamics in leaf area index (LAI) and energy fluxes in order to explore the associated variation in local climate.We show that the increasing trend in LAI contributed to the warming of boreal zones through a reduction of surface albedo and to an evaporation-driven cooling in arid regions. The interplay between LAI and surface biophysics is amplified up to five times under extreme warm-dry and cold-wet years. Altogether, these signals reveal that the recent dynamics in global vegetation have had relevant biophysical impacts on the local climates and should be considered in the design of local mitigation and adaptation plans.},
author = {Forzieri, Giovanni and Alkama, Ramdane and Miralles, Diego G. and Cescatti, Alessandro},
doi = {10.1126/science.aal1727},
issn = {10959203},
journal = {Science},
month = {jun},
number = {6343},
pages = {1180--1184},
publisher = {American Association for the Advancement of Science},
title = {{Satellites reveal contrasting responses of regional climate to the widespread greening of Earth}},
volume = {356},
year = {2017}
}
@article{Foster2017a,
abstract = {Despite an increase in solar output, the Earth's climate has apparently remained relatively stable over geological time. Here, the authors compile atmospheric CO2 data for the past 420 million years and show that this climatic response is due to the long-term decline in this powerful greenhouse gas.},
author = {Foster, Gavin L. and Royer, Dana L. and Lunt, Daniel J.},
doi = {10.1038/ncomms14845},
isbn = {2041-1723},
issn = {2041-1723},
journal = {Nature Communications},
month = {apr},
pages = {14845},
pmid = {28375201},
publisher = {Nature Publishing Group},
title = {{Future climate forcing potentially without precedent in the last 420 million years}},
url = {http://dx.doi.org/10.1038/ncomms14845 http://www.nature.com/doifinder/10.1038/ncomms14845},
volume = {8},
year = {2017}
}
@article{Fowell2018,
abstract = {Abstract Coral reefs are important ecosystems that are increasingly negatively impacted by human activities. Understanding which anthropogenic stressors play the most significant role in their decline is vital for the accurate prediction of future trends in coral reef health and for effective mitigation of these threats. Here we present annually resolved boron and carbon isotope measurements of two cores capturing the past 90 years of growth of the tropical reef-building coral Siderastrea siderea from the Belize Mesoamerican Barrier Reef System. The pairing of these two isotope systems allows us to parse the reconstructed pH change into relative changes in net ecosystem productivity and net ecosystem calcification between the two locations. This approach reveals that the relationship between seawater pH and coral calcification, at both a colony and ecosystem level, is complex and cannot simply be modeled as linear or even positive. This study also underscores both the utility of coupled $\delta$11B-$\delta$13C measurements in tracing past biogeochemical cycling in coral reefs and the complexity of this cycling relative to the open ocean.},
annote = {doi: 10.1002/2017GL076496},
author = {Fowell, S E and Foster, G L and Ries, J B and Castillo, K D and de la Vega, E and Tyrrell, T and Donald, H K and Chalk, T B},
doi = {10.1002/2017GL076496},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Belize,boron isotopes,carbon isotopes,coral},
month = {apr},
number = {7},
pages = {3228--3237},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Historical Trends in pH and Carbonate Biogeochemistry on the Belize Mesoamerican Barrier Reef System}},
url = {https://doi.org/10.1002/2017GL076496 http://doi.wiley.com/10.1002/2017GL076496},
volume = {45},
year = {2018}
}
@article{Frolicher2013,
abstract = {Tropical explosive volcanism is one of the most important natural factors that significantly impact the climate system and the carbon cycle on annual to multi-decadal time scales. The three largest explosive eruptions in the last 50 years - Agung, El Chich{\~{o}}n, and Pinatubo - occurred in spring/summer in conjunction with El Ni{\~{n}}o events and left distinct negative signals in the observational temperature and CO2 records. However, confounding factors such as seasonal variability and El Ni{\~{n}}o-Southern Oscillation (ENSO) may obscure the forcing-response relationship. We determine for the first time the extent to which initial conditions, i.e., season and phase of the ENSO, and internal variability influence the coupled climate and carbon cycle response to volcanic forcing and how this affects estimates of the terrestrial and oceanic carbon sinks. Ensemble simulations with the Earth System Model (Climate System Model 1.4-carbon) predict that the atmospheric CO2 response is ∼60{\%} larger when a volcanic eruption occurs during El Ni{\~{n}}o and in winter than during La Ni{\~{n}}a conditions. Our simulations suggest that the Pinatubo eruption contributed 11 ± 6{\%} to the 25 Pg terrestrial carbon sink inferred over the decade 1990-1999 and -2 ± 1{\%} to the 22 Pg oceanic carbon sink. In contrast to recent claims, trends in the airborne fraction of anthropogenic carbon cannot be detected when accounting for the decadal-scale influence of explosive volcanism and related uncertainties. Our results highlight the importance of considering the role of natural variability in the carbon cycle for interpretation of observations and for data-model intercomparison. {\textcopyright}2013. American Geophysical Union. All Rights Reserved.},
author = {Fr{\"{o}}licher, Thomas Lukas and Joos, Fortunat and Raible, Christoph Cornelius and Sarmiento, Jorge Louis},
doi = {10.1002/gbc.20028},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {carbon cycle,modeling,volcanoes},
number = {1},
pages = {239--251},
title = {{Atmospheric CO2 response to volcanic eruptions: The role of ENSO, season, and variability}},
volume = {27},
year = {2013}
}
@article{Frolicher2018,
author = {Fr{\"{o}}licher, Thomas L. and Laufk{\"{o}}tter, Charlotte},
doi = {10.1038/s41467-018-03163-6},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {650},
title = {{Emerging risks from marine heat waves}},
url = {http://www.nature.com/articles/s41467-018-03163-6},
volume = {9},
year = {2018}
}
@article{Frolicher2015,
author = {Fr{\"{o}}licher, Thomas L and Paynter, David J},
doi = {10.1088/1748-9326/10/7/075002},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jul},
number = {7},
pages = {075002},
publisher = {IOP Publishing},
title = {{Extending the relationship between global warming and cumulative carbon emissions to multi-millennial timescales}},
url = {http://stacks.iop.org/1748-9326/10/i=7/a=075002?key=crossref.8cb7d3783a439ed998be56b6dce26f25 https://iopscience.iop.org/article/10.1088/1748-9326/10/7/075002},
volume = {10},
year = {2015}
}
@article{Frolicher2015b,
abstract = {The authors assess the uptake, transport, and storage of oceanic anthropogenic carbon and heat over the period 1861–2005 in a new set of coupled carbon–climate Earth system models conducted for the fifth phase of the Coupled Model Intercomparison Project (CMIP5), with a particular focus on the Southern Ocean. Simulations show that the Southern Ocean south of 30°S, occupying 30{\%} of global surface ocean area, accounts for 43{\%} ± 3{\%} (42 ± 5 Pg C) of anthropogenic CO2 and 75{\%} ± 22{\%} (23 ± 9 × 1022 J) of heat uptake by the ocean over the historical period. Northward transport out of the Southern Ocean is vigorous, reducing the storage to 33 ± 6 Pg anthropogenic carbon and 12 ± 7 × 1022 J heat in the region. The CMIP5 models, as a class, tend to underestimate the observation-based global anthropogenic carbon storage but simulate trends in global ocean heat storage over the last 50 years within uncertainties of observation-based estimates. CMIP5 models suggest global and Southern Ocean CO2 uptake have been largely unaffected by recent climate variability and change. Anthropogenic carbon and heat storage show a common broad-scale pattern of change, but ocean heat storage is more structured than ocean carbon storage. The results highlight the significance of the Southern Ocean for the global climate and as the region where models differ the most in representation of anthropogenic CO2 and, in particular, heat uptake.},
annote = {From Duplicate 2 (Dominance of the Southern Ocean in Anthropogenic Carbon and Heat Uptake in CMIP5 Models - Fr{\"{o}}licher, Thomas L; Sarmiento, Jorge L; Paynter, David J; Dunne, John P; Krasting, John P; Winton, Michael)

doi: 10.1175/JCLI-D-14-00117.1},
author = {Fr{\"{o}}licher, Thomas L and Sarmiento, Jorge L and Paynter, David J and Dunne, John P and Krasting, John P and Winton, Michael},
doi = {10.1175/JCLI-D-14-00117.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jan},
number = {2},
pages = {862--886},
publisher = {American Meteorological Society},
title = {{Dominance of the Southern Ocean in Anthropogenic Carbon and Heat Uptake in CMIP5 Models}},
type = {Journal Article},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-14-00117.1 https://doi.org/10.1175/JCLI-D-14-00117.1},
volume = {28},
year = {2015}
}
@incollection{Francey2003,
address = {Geneva, Switzerland},
author = {Francey, R. J. and Steele, L. P. and Spencer, D. A. and Langenfelds, R. L. and Law, R. M. and Krummel, P. B. and Fraser, P. J. and Etheridge, D. M. and Derek, N. and Coram, S. A. and Cooper, L. N. and Allison, C. E. and Porter, L. and Baly, S.},
booktitle = {Report of the eleventh WMO/IAEA Meeting of Experts on Carbon Dioxide Concentration and Related Tracer Measurement Techniques},
editor = {Toru, Sasaki and Kazuto, Suda},
pages = {97--111},
publisher = {World Meteorological Organization (WMO)},
series = {WMO TD No. 1138},
title = {{The CSIRO (Australia) measurement of greenhouse gases in the global atmosphere}},
url = {https://library.wmo.int/index.php?lvl=notice{\_}display{\&}id=11080{\#}.YHA{\_}RtV1DIU http://hdl.handle.net/102.100.100/194315?index=1},
year = {2003}
}
@article{Frank2015,
abstract = {The Earth's carbon and hydrologic cycles are intimately coupled by gas exchange through plant stomata. However, uncertainties in the magnitude and consequences of the physiological responses of plants to elevated CO2 in natural environments hinders modelling of terrestrial water cycling and carbon storage. Here we use annually resolved long-term $\delta$13C tree-ring measurements across a European forest network to reconstruct the physiologically driven response of intercellular CO2 (Ci) caused by atmospheric CO2 (Ca) trends. When removing meteorological signals from the $\delta$13C measurements, we find that trees across Europe regulated gas exchange so that for one ppmv atmospheric CO2 increase, Ci increased by {\~{}}0.76 ppmv, most consistent with moderate control towards a constant Ci/Ca ratio. This response corresponds to twentieth-century intrinsic water-use efficiency (iWUE) increases of 14 ± 10 and 22 ± 6{\%} at broadleaf and coniferous sites, respectively. An ensemble of process-based global vegetation models shows similar CO2 effects on iWUE trends. Yet, when operating these models with climate drivers reintroduced, despite decreased stomatal opening, 5{\%} increases in European forest transpiration are calculated over the twentieth century. This counterintuitive result arises from lengthened growing seasons, enhanced evaporative demand in a warming climate, and increased leaf area, which together oppose effects of CO2-induced stomatal closure. Our study questions changes to the hydrological cycle, such as reductions in transpiration and air humidity, hypothesized to result from plant responses to anthropogenic emissions.},
archivePrefix = {arXiv},
arxivId = {arXiv:1011.1669v3},
author = {Frank, D. C. and Poulter, B. and Saurer, M. and Esper, J. and Huntingford, C. and Helle, G. and Treydte, K. and Zimmermann, N. E. and Schleser, G. H. and Ahlstr{\"{o}}m, A. and Ciais, P. and Friedlingstein, P. and Levis, S. and Lomas, M. and Sitch, S. and Viovy, N. and Andreu-Hayles, L. and Bednarz, Z. and Berninger, F. and Boettger, T. and D‘Alessandro, C. M. and Daux, V. and Filot, M. and Grabner, M. and Gutierrez, E. and Haupt, M. and Hilasvuori, E. and Jungner, H. and Kalela-Brundin, M. and Krapiec, M. and Leuenberger, M. and Loader, N. J. and Marah, H. and Masson-Delmotte, V. and Pazdur, A. and Pawelczyk, S. and Pierre, M. and Planells, O. and Pukiene, R. and Reynolds-Henne, C. E. and Rinne, K. T. and Saracino, A. and Sonninen, E. and Stievenard, M. and Switsur, V. R. and Szczepanek, M. and Szychowska-Krapiec, E. and Todaro, L. and Waterhouse, J. S. and Weigl, M.},
doi = {10.1038/nclimate2614},
eprint = {arXiv:1011.1669v3},
isbn = {1758-6798},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jun},
number = {6},
pages = {579--583},
pmid = {24907466},
title = {{Water-use efficiency and transpiration across European forests during the Anthropocene}},
url = {http://www.nature.com/articles/nclimate2614},
volume = {5},
year = {2015}
}
@article{Fransson2017,
author = {Fransson, Agneta and Chierici, Melissa and Skjelvan, Ingunn and Olsen, Are and Assmy, Philipp and Peterson, Algot K. and Spreen, Gunnar and Ward, Brian},
doi = {10.1002/2016JC012478},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
month = {jul},
number = {7},
pages = {5566--5587},
title = {{Effects of sea-ice and biogeochemical processes and storms on under-ice water fCO2 during the winter-spring transition in the high Arctic Ocean: Implications for sea-air CO2 fluxes}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2016JC012478},
volume = {122},
year = {2017}
}
@article{Fransson2015,
author = {Fransson, Agneta and Chierici, Melissa and Nomura, Daiki and Granskog, Mats A. and Kristiansen, Svein and Martma, T{\~{o}}nu and Nehrke, Gernot},
doi = {10.1002/2014JC010320},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
month = {apr},
number = {4},
pages = {2413--2429},
title = {{Effect of glacial drainage water on the CO2 system and ocean acidification state in an Arctic tidewater‐glacier fjord during two contrasting years}},
url = {http://doi.wiley.com/10.1002/2014JC010320 https://onlinelibrary.wiley.com/doi/10.1002/2014JC010320},
volume = {120},
year = {2015}
}
@article{Freing2012,
abstract = {We use transient time distributions calculated from tracer data together with in situ measurements of nitrous oxide (N(2)O) to estimate the concentration of biologically produced N(2)O and N(2)O production rates in the ocean on a global scale. Our approach to estimate the N(2)O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We estimate that the oceanic N(2)O production is dominated by nitrification with a contribution of only approximately 7 per cent by denitrification. This indicates that previously used approaches have overestimated the contribution by denitrification. Shelf areas may account for only a negligible fraction of the global production; however, estuarine sources and coastal upwelling of N(2)O are not taken into account in our study. The largest amount of subsurface N(2)O is produced in the upper 500 m of the water column. The estimated global annual subsurface N(2)O production ranges from 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr(-1). This is in agreement with estimates of the global N(2)O emissions to the atmosphere and indicates that a N(2)O source in the mixed layer is unlikely. The potential future development of the oceanic N(2)O source in view of the ongoing changes of the ocean environment (deoxygenation, warming, eutrophication and acidification) is discussed.},
author = {Freing, Alina and Wallace, Douglas W R and Bange, Hermann W},
doi = {10.1098/rstb.2011.0360},
issn = {0962-8436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
month = {may},
number = {1593},
pages = {1245--1255},
pmid = {22451110},
publisher = {The Royal Society},
title = {{Global oceanic production of nitrous oxide}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/22451110 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC3306629 http://rstb.royalsocietypublishing.org/cgi/doi/10.1098/rstb.2011.0360},
volume = {367},
year = {2012}
}
@article{doi:10.1034/j.1600-0889.2003.01461.x,
abstract = {Future climate change induced by atmospheric emissions of greenhouse gases is believed to have a large impact on the global carbon cycle. Several offline studies focusing either on the marine or on the terrestrial carbon cycle highlighted such potential effects. Two recent online studies, using ocean–atmosphere general circulation models coupled to land and ocean carbon cycle models, investigated in a consistent way the feedback between the climate change and the carbon cycle. These two studies used observed anthropogenic CO2 emissions for the 1860–1995 period and IPCC scenarios for the 1995–2100 period to force the climate – carbon cycle models. The study from the Hadley Centre group showed a very large positive feedback, atmospheric CO2 reaching 980 ppmv by 2100 if future climate impacts on the carbon cycle, but only about 700 ppmv if the carbon cycle is included but assumed to be insensitive to the climate change. The IPSL coupled climate – carbon cycle model simulated a much smaller positive feedback: climate impact on the carbon cycle leads by 2100 to an addition of less than 100 ppmv in the atmosphere. Here we perform a detailed feedback analysis to show that such differences are due to two key processes that are still poorly constrained in these coupled models: first Southern Ocean circulation, which primarily controls the geochemical uptake of CO2, and second vegetation and soil carbon response to global warming. Our analytical analysis reproduces remarkably the results obtained by the fully coupled models. Also it allows us to identify that, amongst the two processes mentioned above, the latter (the land response to global warming) is the one that essentially explains the differences between the IPSL and the Hadley results.},
author = {Friedlingstein, P. and Dufresne, J.-L. and Cox, P. M. and Rayner, P.},
doi = {10.1034/j.1600-0889.2003.01461.x},
issn = {0280-6509},
journal = {Tellus B},
month = {apr},
number = {2},
pages = {692--700},
title = {{How positive is the feedback between climate change and the carbon cycle?}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1034/j.1600-0889.2003.01461.x http://www.tellusb.net/index.php/tellusb/article/view/16765},
volume = {55},
year = {2003}
}
@article{Friedlingstein2014,
abstract = {In the context of phase 5 of the Coupled Model Intercomparison Project, most climate simulations use prescribed atmospheric CO2 concentration and therefore do not interactively include the effect of carbon cycle feedbacks. However, the representative concentration pathway 8.5 (RCP8.5) scenario has additionally been run by earth system models with prescribed CO2 emissions. This paper analyzes the climate projections of 11 earth system models (ESMs) that performed both emission-driven and concentration-driven RCP8.5 simulations. When forced by RCP8.5 CO2 emissions, models simulate a large spread in atmospheric CO2; the simulated 2100 concentrations range between 795 and 1145 ppm. Seven out of the 11 ESMs simulate a larger CO2 (on average by 44 ppm, 985 ± 97 ppm by 2100) and hence higher radiative forcing (by 0.25 W m−2) when driven by CO2 emissions than for the concentration-driven scenarios (941 ppm). However, most of these models already overestimate the present-day CO2, with the present-day biases reasonably well correlated with future atmospheric concentrations' departure from the prescribed concentration. The uncertainty in CO2 projections is mainly attributable to uncertainties in the response of the land carbon cycle. As a result of simulated higher CO2 concentrations than in the concentration-driven simulations, temperature projections are generally higher when ESMs are driven with CO2 emissions. Global surface temperature change by 2100 (relative to present day) increased by 3.9° ± 0.9°C for the emission-driven simulations compared to 3.7° ± 0.7°C in the concentration-driven simulations. Although the lower ends are comparable in both sets of simulations, the highest climate projections are significantly warmer in the emission-driven simulations because of stronger carbon cycle feedbacks.},
author = {Friedlingstein, Pierre and Meinshausen, Malte and Arora, Vivek K and Jones, Chris D and Anav, Alessandro and Liddicoat, Spencer K and Knutti, Reto},
doi = {10.1175/JCLI-D-12-00579.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jan},
number = {2},
pages = {511--526},
title = {{Uncertainties in CMIP5 climate projections due to carbon cycle feedbacks}},
type = {Journal Article},
url = {https://journals.ametsoc.org/doi/10.1175/JCLI-D-12-00579.1 http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00579.1},
volume = {27},
year = {2014}
}
@article{Friedlingstein2014b,
abstract = {{\"{i}}¿½ 2014 Macmillan Publishers Limited. All rights reserved. Efforts to limit climate change below a given temperature level require that global emissions of CO2cumulated over time remain below a limited quota. This quota varies depending on the temperature level, the desired probability of staying below this level and the contributions of other gases. In spite of this restriction, global emissions of CO2from fossil fuel combustion and cement production have continued to grow by 2.5{\%} per year on average over the past decade. Two thirds of the CO2emission quota consistent with a 2{\"{i}}¿½C temperature limit has already been used, and the total quota will likely be exhausted in a further 30 years at the 2014 emissions rates. We show that CO2emissions track the high end of the latest generation of emissions scenarios, due to lower than anticipated carbon intensity improvements of emerging economies and higher global gross domestic product growth. In the absence of more stringent mitigation, these trends are set to continue and further reduce the remaining quota until the onset of a potential new climate agreement in 2020. Breaking current emission trends in the short term is key to retaining credible climate targets within a rapidly diminishing emission quota.},
author = {Friedlingstein, P. and Andrew, R. M. and Rogelj, J. and Peters, G. P. and Canadell, J. G. and Knutti, R. and Luderer, G. and Raupach, M. R. and Schaeffer, M. and van Vuuren, D. P. and {Le Qu{\'{e}}r{\'{e}}}, C.},
doi = {10.1038/ngeo2248},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {oct},
number = {10},
pages = {709--715},
title = {{Persistent growth of CO2 emissions and implications for reaching climate targets}},
url = {http://www.nature.com/articles/ngeo2248},
volume = {7},
year = {2014}
}
@article{Friedlingstein2019,
author = {Friedlingstein, Pierre and Jones, Matthew W. and O'Sullivan, Michael and Andrew, Robbie M. and Hauck, Judith and Peters, Glen P. and Peters, Wouter and Pongratz, Julia and Sitch, Stephen and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Bakker, Dorothee C. E. and Canadell, Josep G. and Ciais, Philippe and Jackson, Robert B. and Anthoni, Peter and Barbero, Leticia and Bastos, Ana and Bastrikov, Vladislav and Becker, Meike and Bopp, Laurent and Buitenhuis, Erik and Chandra, Naveen and Chevallier, Fr{\'{e}}d{\'{e}}ric and Chini, Louise P. and Currie, Kim I. and Feely, Richard A. and Gehlen, Marion and Gilfillan, Dennis and Gkritzalis, Thanos and Goll, Daniel S. and Gruber, Nicolas and Gutekunst, S{\"{o}}ren and Harris, Ian and Haverd, Vanessa and Houghton, Richard A. and Hurtt, George and Ilyina, Tatiana and Jain, Atul K. and Joetzjer, Emilie and Kaplan, Jed O. and Kato, Etsushi and {Klein Goldewijk}, Kees and Korsbakken, Jan Ivar and Landsch{\"{u}}tzer, Peter and Lauvset, Siv K. and Lef{\`{e}}vre, Nathalie and Lenton, Andrew and Lienert, Sebastian and Lombardozzi, Danica and Marland, Gregg and McGuire, Patrick C. and Melton, Joe R. and Metzl, Nicolas and Munro, David R. and Nabel, Julia E. M. S. and Nakaoka, Shin-Ichiro and Neill, Craig and Omar, Abdirahman M. and Ono, Tsuneo and Peregon, Anna and Pierrot, Denis and Poulter, Benjamin and Rehder, Gregor and Resplandy, Laure and Robertson, Eddy and R{\"{o}}denbeck, Christian and S{\'{e}}f{\'{e}}rian, Roland and Schwinger, J{\"{o}}rg and Smith, Naomi and Tans, Pieter P. and Tian, Hanqin and Tilbrook, Bronte and Tubiello, Francesco N. and van der Werf, Guido R. and Wiltshire, Andrew J. and Zaehle, S{\"{o}}nke},
doi = {10.5194/essd-11-1783-2019},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {dec},
number = {4},
pages = {1783--1838},
title = {{Global Carbon Budget 2019}},
url = {https://www.earth-syst-sci-data.net/11/1783/2019/ https://essd.copernicus.org/articles/11/1783/2019/},
volume = {11},
year = {2019}
}
@article{Friedlingstein2006a,
abstract = {Eleven coupled climate–carbon cycle models used a common protocol to study the coupling between climate change and the carbon cycle. The models were forced by historical emissions and the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) A2 anthropogenic emissions of CO 2 for the 1850–2100 time period. For each model, two simulations were performed in order to isolate the impact of climate change on the land and ocean carbon cycle, and therefore the climate feedback on the atmospheric CO 2 concentration growth rate. There was unanimous agreement among the models that future climate change will reduce the efficiency of the earth system to absorb the anthropogenic carbon perturbation. A larger fraction of anthropogenic CO 2 will stay airborne if climate change is accounted for. By the end of the twenty-first century, this additional CO 2 varied between 20 and 200 ppm for the two extreme models, the majority of the models lying between 50 and 100 ppm. The higher CO 2 levels led to an additional climate warming ranging between 0.1° and 1.5°C.},
author = {Friedlingstein, P. and Cox, P. and Betts, R. and Bopp, L. and von Bloh, W. and Brovkin, V. and Cadule, P. and Doney, S. and Eby, M. and Fung, I. and Bala, G. and John, J. and Jones, C. and Joos, F. and Kato, T. and Kawamiya, M. and Knorr, W. and Lindsay, K. and Matthews, H. D. and Raddatz, T. and Rayner, P. and Reick, C. and Roeckner, E. and Schnitzler, K.-G. and Schnur, R. and Strassmann, K. and Weaver, A. J. and Yoshikawa, C. and Zeng, N.},
doi = {10.1175/JCLI3800.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jul},
number = {14},
pages = {3337--3353},
title = {{Climate–Carbon Cycle Feedback Analysis: Results from the C4MIP Model Intercomparison}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI3800.1},
volume = {19},
year = {2006}
}
@article{Friedlingstein2020,
author = {Friedlingstein, Pierre and O'Sullivan, Michael and Jones, Matthew W. and Andrew, Robbie M. and Hauck, Judith and Olsen, Are and Peters, Glen P. and Peters, Wouter and Pongratz, Julia and Sitch, Stephen and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Canadell, Josep G. and Ciais, Philippe and Jackson, Robert B. and Alin, Simone and Arag{\~{a}}o, Luiz E. O. C. and Arneth, Almut and Arora, Vivek and Bates, Nicholas R. and Becker, Meike and Benoit-Cattin, Alice and Bittig, Henry C. and Bopp, Laurent and Bultan, Selma and Chandra, Naveen and Chevallier, Fr{\'{e}}d{\'{e}}ric and Chini, Louise P. and Evans, Wiley and Florentie, Liesbeth and Forster, Piers M. and Gasser, Thomas and Gehlen, Marion and Gilfillan, Dennis and Gkritzalis, Thanos and Gregor, Luke and Gruber, Nicolas and Harris, Ian and Hartung, Kerstin and Haverd, Vanessa and Houghton, Richard A. and Ilyina, Tatiana and Jain, Atul K. and Joetzjer, Emilie and Kadono, Koji and Kato, Etsushi and Kitidis, Vassilis and Korsbakken, Jan Ivar and Landsch{\"{u}}tzer, Peter and Lef{\`{e}}vre, Nathalie and Lenton, Andrew and Lienert, Sebastian and Liu, Zhu and Lombardozzi, Danica and Marland, Gregg and Metzl, Nicolas and Munro, David R. and Nabel, Julia E. M. S. and Nakaoka, Shin-Ichiro and Niwa, Yosuke and O'Brien, Kevin and Ono, Tsuneo and Palmer, Paul I. and Pierrot, Denis and Poulter, Benjamin and Resplandy, Laure and Robertson, Eddy and R{\"{o}}denbeck, Christian and Schwinger, J{\"{o}}rg and S{\'{e}}f{\'{e}}rian, Roland and Skjelvan, Ingunn and Smith, Adam J. P. and Sutton, Adrienne J. and Tanhua, Toste and Tans, Pieter P. and Tian, Hanqin and Tilbrook, Bronte and van der Werf, Guido and Vuichard, Nicolas and Walker, Anthony P. and Wanninkhof, Rik and Watson, Andrew J. and Willis, David and Wiltshire, Andrew J. and Yuan, Wenping and Yue, Xu and Zaehle, S{\"{o}}nke},
doi = {10.5194/essd-12-3269-2020},
issn = {1866-3516},
journal = {Earth System Science Data},
language = {L7664},
month = {dec},
number = {4},
pages = {3269--3340},
title = {{Global Carbon Budget 2020}},
url = {https://essd.copernicus.org/preprints/essd-2020-286/ https://essd.copernicus.org/articles/12/3269/2020/},
volume = {12},
year = {2020}
}
@article{Friend2014,
abstract = {Future climate change and increasing atmospheric CO2 are expected to cause major changes in vegetation structure and function over large fractions of the global land surface. Seven global vegetation models are used to analyze possible responses to future climate simulated by a range of general circulation models run under all four representative concentration pathway scenarios of changing concentrations of greenhouse gases. All 110 simulations predict an increase in global vegetation carbon to 2100, but with substantial variation between vegetation models. For example, at 4 {\$}\backslash,{\^{}}{\{}\backslashcirc{\}}{\$}C of global land surface warming (510--758 ppm of CO2), vegetation carbon increases by 52--477 Pg C (224 Pg C mean), mainly due to CO2 fertilization of photosynthesis. Simulations agree on large regional increases across much of the boreal forest, western Amazonia, central Africa, western China, and southeast Asia, with reductions across southwestern North America, central South America, southern Mediterranean areas, southwestern Africa, and southwestern Australia. Four vegetation models display discontinuities across 4 {\$}\backslash,{\^{}}{\{}\backslashcirc{\}}{\$}C of warming, indicating global thresholds in the balance of positive and negative influences on productivity and biomass. In contrast to previous global vegetation model studies, we emphasize the importance of uncertainties in projected changes in carbon residence times. We find, when all seven models are considered for one representative concentration pathway × general circulation model combination, such uncertainties explain 30{\%} more variation in modeled vegetation carbon change than responses of net primary productivity alone, increasing to 151{\%} for non-HYBRID4 models. A change in research priorities away from production and toward structural dynamics and demographic processes is recommended.},
author = {Friend, Andrew D and Lucht, Wolfgang and Rademacher, Tim T and Keribin, Rozenn and Betts, Richard and Cadule, Patricia and Ciais, Philippe and Clark, Douglas B and Dankers, Rutger and Falloon, Pete D and Ito, Akihiko and Kahana, Ron and Kleidon, Axel and Lomas, Mark R and Nishina, Kazuya and Ostberg, Sebastian and Pavlick, Ryan and Peylin, Philippe and Schaphoff, Sibyll and Vuichard, Nicolas and Warszawski, Lila and Wiltshire, Andy and Woodward, F Ian},
doi = {10.1073/pnas.1222477110},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {mar},
number = {9},
pages = {3280--3285},
title = {{Carbon residence time dominates uncertainty in terrestrial vegetation responses to future climate and atmospheric CO2}},
url = {http://www.pnas.org/content/111/9/3280 http://www.pnas.org/lookup/doi/10.1073/pnas.1222477110},
volume = {111},
year = {2014}
}
@article{bg-13-5151-2016,
abstract = {Abstract. We examine climate change impacts on net primary production (NPP) and export production (sinking particulate flux; EP) with simulations from nine Earth system models (ESMs) performed in the framework of the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Global NPP and EP are reduced by the end of the century for the intense warming scenario of Representative Concentration Pathway (RCP) 8.5. Relative to the 1990s, NPP in the 2090s is reduced by 2–16{\%} and EP by 7–18{\%}. The models with the largest increases in stratification (and largest relative declines in NPP and EP) also show the largest positive biases in stratification for the contemporary period, suggesting overestimation of climate change impacts on NPP and EP. All of the CMIP5 models show an increase in stratification in response to surface–ocean warming and freshening, which is accompanied by decreases in surface nutrients, NPP and EP. There is considerable variability across the models in the magnitudes of NPP, EP, surface nutrient concentrations and their perturbations by climate change. The negative response of NPP and EP to increasing stratification reflects primarily a bottom-up control, as upward nutrient flux declines at the global scale. Models with dynamic phytoplankton community structure show larger declines in EP than in NPP. This pattern is driven by phytoplankton community composition shifts, with reductions in productivity by large phytoplankton as smaller phytoplankton (which export less efficiently) are favored under the increasing nutrient stress. Thus, the projections of the NPP response to climate change are critically dependent on the simulated phytoplankton community structure, the efficiency of the biological pump and the resulting levels of regenerated production, which vary widely across the models. Community structure is represented simply in the CMIP5 models, and should be expanded to better capture the spatial patterns and climate-driven changes in export efficiency.},
author = {Fu, Weiwei and Randerson, James T and Moore, J Keith},
doi = {10.5194/bg-13-5151-2016},
issn = {1726-4189},
journal = {Biogeosciences},
month = {sep},
number = {18},
pages = {5151--5170},
title = {{Climate change impacts on net primary production (NPP) and export production (EP) regulated by increasing stratification and phytoplankton community structure in the CMIP5 models}},
url = {https://www.biogeosciences.net/13/5151/2016/},
volume = {13},
year = {2016}
}
@article{Fujita2020,
author = {Fujita, Ryo and Morimoto, Shinji and Maksyutov, Shamil and Kim, Heon‐Sook and Arshinov, Mikhail and Brailsford, Gordon and Aoki, Shuji and Nakazawa, Takakiyo},
doi = {10.1029/2020JD032903},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jul},
number = {14},
pages = {e2020JD032903},
title = {{Global and Regional CH4 Emissions for 1995–2013 Derived From Atmospheric CH4, $\delta$13C‐CH4 , and $\delta$D‐CH4 Observations and a Chemical Transport Model}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020JD032903},
volume = {125},
year = {2020}
}
@article{Fuss2018a,
abstract = {The most recent IPCC assessment has left little doubt that negative emissions technologies (NETs) will play an important role in limiting warming to 2°C cost-effectively. However, currently absent is a bottom-up, systematic, reproducible, and transparent literature assessment of the different options to remove carbon from the atmosphere. In part 1 of this three-part review on NETs, we assemble a comprehensive set of relevant literature so far published, focusing on 7 technologies: bioenergy with carbon capture and storage (BECCS), afforestation and reforestation, direct air capture and storage, enhanced weathering, ocean fertilisation, biochar, and soil carbon sequestration. In this part, part 2 of the review, we comprehensively present estimates of costs, potentials, and side-effects for these technologies, and qualify them with our expert judgement. Part 3 reviews the innovation and scaling challenges that must be addressed to realise NETs deployment as a viable climate mitigation strategy. Taking into account a systematic review of the literature, our best estimates for sustainable global NET potentials in 2050 are 0.5-3.6 GtCO2/year for afforestation and reforestation, 0.5-5 GtCO2/year for BECCS, 0.2-2GtCO2/year for biochar, 2-4 GtCO2/year for enhanced weathering, 0.5-5 GtCO2/year for direct air capture, and up to 5 GtCO2/year for soil carbon sequestration. Costs vary widely across the technologies, as does their permanency and cumulative potentials. It is unlikely that a single NET will be able to sustainably meet the rates of carbon uptake described in integrated assessment pathways consistent with 1.5°C of warming.},
archivePrefix = {arXiv},
arxivId = {NIHMS150003},
author = {Fuss, Sabine and Lamb, William F. and Callaghan, Max W. and Hilaire, J{\'{e}}r{\^{o}}me and Creutzig, Felix and Amann, Thorben and Beringer, Tim and {de Oliveira Garcia}, Wagner and Hartmann, Jens and Khanna, Tarun and Luderer, Gunnar and Nemet, Gregory F. and Rogelj, Joeri and Smith, Pete and Vicente, Jos{\'{e}} Luis Vicente and Wilcox, Jennifer and {del Mar Zamora Dominguez}, Maria and Minx, Jan C.},
doi = {10.1088/1748-9326/aabf9f},
eprint = {NIHMS150003},
isbn = {1070-9878},
issn = {1748-9326},
journal = {Environmental Research Letters},
keywords = {carbon dioxide removal,climate change mitigation,negative emission technologies,scenarios},
language = {en},
month = {jun},
number = {6},
pages = {063002},
pmid = {24335434},
title = {{Negative emissions – Part 2: Costs, potentials and side effects}},
url = {http://stacks.iop.org/1748-9326/13/i=6/a=063002?key=crossref.280beee8a19ff00042252ae3ce163a06 https://iopscience.iop.org/article/10.1088/1748-9326/aabf9f},
volume = {13},
year = {2018}
}
@article{Gunther2020,
abstract = {Peatlands are strategic areas for climate change mitigation because of their matchless carbon stocks. Drained peatlands release this carbon to the atmosphere as carbon dioxide (CO2). Peatland rewetting effectively stops these CO2 emissions, but also re-establishes the emission of methane (CH4). Essentially, management must choose between CO2 emissions from drained, or CH4 emissions from rewetted, peatland. This choice must consider radiative effects and atmospheric lifetimes of both gases, with CO2 being a weak but persistent, and CH4 a strong but short-lived, greenhouse gas. The resulting climatic effects are, thus, strongly time-dependent. We used a radiative forcing model to compare forcing dynamics of global scenarios for future peatland management using areal data from the Global Peatland Database. Our results show that CH4 radiative forcing does not undermine the climate change mitigation potential of peatland rewetting. Instead, postponing rewetting increases the long-term warming effect through continued CO2 emissions.},
author = {G{\"{u}}nther, Anke and Barthelmes, Alexandra and Huth, Vytas and Joosten, Hans and Jurasinski, Gerald and Koebsch, Franziska and Couwenberg, John},
doi = {10.1038/s41467-020-15499-z},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {1644},
title = {{Prompt rewetting of drained peatlands reduces climate warming despite methane emissions}},
url = {https://doi.org/10.1038/s41467-020-15499-z},
volume = {11},
year = {2020}
}
@article{Galbraith2013,
abstract = {Over much of the ocean's surface, productivity and growth are limited by a scarcity of bioavailable nitrogen. Sedimentary $\delta$15N records spanning the last deglaciation suggest marked shifts in the nitrogen cycle during this time, but the quantification of these changes has been hindered by the complexity of nitrogen isotope cycling. Here we present a database of $\delta$15N in sediments throughout the world's oceans, including 2,329 modern seafloor samples, and 76 timeseries spanning the past 30,000 years. We show that the $\delta$15N values of modern seafloor sediments are consistent with values predicted by our knowledge of nitrogen cycling in the water column. Despite many local deglacial changes, the globally averaged $\delta$15N values of sinking organic matter were similar during the Last Glacial Maximum and Early Holocene. Considering the global isotopic mass balance, we explain these observations with the following deglacial history of nitrogen inventory processes. During the Last Glacial Maximum, the nitrogen cycle was near steady state. During the deglaciation, denitrification in the pelagic water column accelerated. The flooding of continental shelves subsequently increased denitrification at the seafloor, and denitrification reached near steady-state conditions again in the Early Holocene. We use a recent parameterization of seafloor denitrification to estimate a 30–120{\%} increase in benthic denitrification between 15,000 and 8,000 years ago. Based on the similarity of globally averaged $\delta$15N values during the Last Glacial Maximum and Early Holocene, we infer that pelagic denitrification must have increased by a similar amount between the two steady states.},
address = {Department of Earth and Planetary Science, McGill University, 3450 University Street, Montreal, Quebec H3A 2A7, Canada},
annote = {10.1038/ngeo1832},
author = {Galbraith, Eric D and Kienast, Markus},
doi = {10.1038/ngeo1832},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jul},
number = {7},
pages = {579--584},
title = {{The acceleration of oceanic denitrification during deglacial warming}},
url = {http://dx.doi.org/10.1038/ngeo1832 http://www.nature.com/doifinder/10.1038/ngeo1832 http://www.nature.com/articles/ngeo1832},
volume = {6},
year = {2013}
}
@article{Galbraith2015,
abstract = {Among the many potential explanations for the 80ppm rise of atmospheric CO2concentrations at the end of the last ice age, most involve a weakening of the oceanic soft tissue pump. Here we use global data compilations of sedimentary nitrogen isotopes and benthic oxygenation proxies to provide a synoptic global perspective on the deglacial soft tissue pump weakening. The net change between the Last Glacial Maximum and Holocene shows a removal of respired carbon everywhere that proxy data is available, with the exception of the upper 1.5km of the North Pacific, while excess nitrate accumulated in polar oceans. These observations could be explained by intensifying iron limitation, a shoaling of organic matter remineralization, and/or a change in ocean circulation, but are inconsistent with a change in the magnitude or position of the Southern mid-latitude westerlies. The net soft tissue pump weakening was front-loaded in the early deglaciation ({\~{}}17.5-{\~{}}14ka), when atmospheric $\delta$13C and $\delta$14C were changing rapidly, and appears to have contributed little net change thereafter. Superimposed on the overall deglacial trend were pronounced transient changes that coincided with variability in the Atlantic Meridional Overturning Circulation (AMOC) and bipolar seesaw. The seesaw variability is most clearly expressed as anti-phased oxygenation changes between the upper 1.5km of the North Pacific and the deep North Atlantic, consistent with an Atlantic-Pacific ventilation seesaw, but it dominated transient variability in records throughout the world. Although the soft tissue pump seesaw made little contribution to the contrast between the glacial and interglacial states, it could have contributed to deglacial variability in atmospheric CO2and might have catalyzed the deglaciation.},
author = {Galbraith, Eric D. and Jaccard, Samuel L.},
doi = {10.1016/j.quascirev.2014.11.012},
issn = {02773791},
journal = {Quaternary Science Reviews},
keywords = {Biological pump,Carbon dioxide,Dissolved oxygen,Ice ages,Iron fertilization,Marine sediments,Nitrogen isotopes,Ocean circulation},
month = {feb},
pages = {38--48},
title = {{Deglacial weakening of the oceanic soft tissue pump: global constraints from sedimentary nitrogen isotopes and oxygenation proxies}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379114004697},
volume = {109},
year = {2015}
}
@article{Galbraith2020,
abstract = {Much of the global cooling during ice ages arose from changes in ocean carbon storage that lowered atmospheric CO 2 . A slew of mechanisms, both physical and biological, have been proposed as key drivers of these changes. Here we discuss the current understanding of these mechanisms with a focus on how they altered the theoretically defined soft-tissue and biological disequilibrium carbon storage at the peak of the last ice age. Observations and models indicate a role for Antarctic sea ice through its influence on ocean circulation patterns, but other mechanisms, including changes in biological processes, must have been important as well, and may have been coordinated through links with global air temperature. Further research is required to better quantify the contributions of the various mechanisms, and there remains great potential to use the Last Glacial Maximum and the ensuing global warming as natural experiments from which to learn about climate-driven changes in the marine ecosystem.},
author = {Galbraith, Eric D. and Skinner, Luke C.},
doi = {10.1146/annurev-marine-010419-010906},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {559--586},
title = {{The biological pump during the Last Glacial Maximum}},
url = {https://www.annualreviews.org/doi/10.1146/annurev-marine-010419-010906},
volume = {12},
year = {2020}
}
@article{cp-13-1695-2017,
abstract = {Abstract. In spite of significant progress in paleoclimate reconstructions and modelling of different aspects of the past glacial cycles, the mechanisms which transform regional and seasonal variations in solar insolation into long-term and global-scale glacial{\&}ndash;interglacial cycles are still not fully understood {\&}ndash; in particular, in relation to CO2 variability. Here using the Earth system model of intermediate complexity CLIMBER-2 we performed simulations of the co-evolution of climate, ice sheets, and carbon cycle over the last 400000 years using the orbital forcing as the only external forcing. The model simulates temporal dynamics of CO2, global ice volume, and other climate system characteristics in good agreement with paleoclimate reconstructions. These results provide strong support for the idea that long and strongly asymmetric glacial cycles of the late Quaternary represent a direct but strongly nonlinear response of the Northern Hemisphere ice sheets to orbital forcing. This response is strongly amplified and globalised by the carbon cycle feedbacks. Using simulations performed with the model in different configurations, we also analyse the role of individual processes and sensitivity to the choice of model parameters. While many features of simulated glacial cycles are rather robust, some details of CO2 evolution, especially during glacial terminations, are sensitive to the choice of model parameters. Specifically, we found two major regimes of CO2 changes during terminations: in the first one, when the recovery of the Atlantic meridional overturning circulation (AMOC) occurs only at the end of the termination, a pronounced overshoot in CO2 concentration occurs at the beginning of the interglacial and CO2 remains almost constant during the interglacial or even declines towards the end, resembling Eemian CO2 dynamics. However, if the recovery of the AMOC occurs in the middle of the glacial termination, CO2 concentration continues to rise during the interglacial, similar to the Holocene. We also discuss the potential contribution of the brine rejection mechanism for the CO2 and carbon isotopes in the atmosphere and the ocean during the past glacial termination.},
author = {Ganopolski, Andrey and Brovkin, Victor},
doi = {10.5194/cp-13-1695-2017},
issn = {1814-9332},
journal = {Climate of the Past},
month = {nov},
number = {12},
pages = {1695--1716},
title = {{Simulation of climate, ice sheets and CO2 evolution during the last four glacial cycles with an Earth system model of intermediate complexity}},
url = {https://www.clim-past.net/13/1695/2017/},
volume = {13},
year = {2017}
}
@article{Gao2020a,
abstract = {As the world's largest CH4 emitter, China's CH4 emissions contribute to climate change more than the amount emitted by many developed countries combined. The rapid growth of China's coal demand has important implications for CH4 emissions from coal mining or coal mine methane (CMM) emissions. This paper aims to present an overview of bottom-up estimation of China's CMM emissions, including the trend in the last four decades and the limitations of current understanding on CH4 emissions. Although characterized by significant differences in inventory compilation, statistically, the total CMM emissions rose from 4.64 to 16.41 Tg with a peak of 21.48 Tg from 1980 to 2016. Large discrepancies of inventory results existed in previous studies, which were affected by the coverage of emission sources, emission factors and activity-level data. The disagreements can be largely attributable to the emission factors of underground mining, which contain substantial variances in both spatial and temporal dimensions. To develop more reliable CMM inventories and make targeted mitigation measures, more attention should be paid to the transparency of the estimated results, coal statistics, on-site CMM emission factors, and the emissions from abandoned coal mines. As the leading CH4 emission source in China, the estimations of CMM emissions urgently need to overcome existing and emerging challenges for compiling a consistent and accurate inventory.},
author = {Gao, Junlian and Guan, Cheng He and Zhang, Bo},
doi = {10.1016/j.scitotenv.2020.138295},
issn = {18791026},
journal = {Science of the Total Environment},
keywords = {China,Coal mining,Greenhouse gas emission inventories,Literature review,Methane emissions},
pages = {138295},
pmid = {32278176},
publisher = {Elsevier B.V.},
title = {{China's CH4 emissions from coal mining: A review of current bottom-up inventories}},
url = {https://doi.org/10.1016/j.scitotenv.2020.138295},
volume = {725},
year = {2020}
}
@article{Gasser2020,
abstract = {Emissions from land use and land cover change are a key component of the global carbon cycle. However, models are required to disentangle these emissions from the land carbon sink, as only the sum of both can be physically observed. Their assessment within the yearly communitywide effort known as the "Global Carbon Budget"remains a major difficulty, because it combines two lines of evidence that are inherently inconsistent: bookkeeping models and dynamic global vegetation models. Here, we propose a unifying approach that relies on a bookkeeping model, which embeds processes and parameters calibrated on dynamic global vegetation models, and the use of an empirical constraint. We estimate that the global CO 2 emissions from land use and land cover change were 1:36±0:42 PgC yr -1 (1$\sigma$ range) on average over the 2009-2018 period and reached a cumulative total of 206±57 PgC over the 1750-2018 period. We also estimate that land cover change induced a global loss of additional sink capacity - that is, a foregone carbon removal, not part of the emissions - of 0:68±0:57 PgC yr -1 and 32±23 PgC over the same periods, respectively. Additionally, we provide a breakdown of our results' uncertainty, including aspects such as the land use and land cover change data sets used as input and the model's biogeochemical parameters. We find that the biogeochemical uncertainty dominates our global and regional estimates with the exception of tropical regions in which the input data dominates. Our analysis further identifies key sources of uncertainty and suggests ways to strengthen the robustness of future Global Carbon Budget estimates.},
author = {Gasser, Thomas and Crepin, Le{\'{a}} and Quilcaille, Yann and Houghton, Richard A. and Ciais, Philippe and Obersteiner, Michael},
doi = {10.5194/bg-17-4075-2020},
issn = {17264189},
journal = {Biogeosciences},
number = {15},
pages = {4075--4101},
title = {{Historical CO2 emissions from land use and land cover change and their uncertainty}},
volume = {17},
year = {2020}
}
@article{Gasser2017,
abstract = {Abstract. Most emission metrics have previously been inconsistently estimated by including the climate–carbon feedback for the reference gas (i.e. CO2) but not the other species (e.g. CH4). In the fifth assessment report of the IPCC, a first attempt was made to consistently account for the climate–carbon feedback in emission metrics. This attempt was based on only one study, and therefore the IPCC concluded that more research was needed. Here, we carry out this research. First, using the simple Earth system model OSCAR v2.2, we establish a new impulse response function for the climate–carbon feedback. Second, we use this impulse response function to provide new estimates for the two most common metrics: global warming potential (GWP) and global temperature-change potential (GTP). We find that, when the climate–carbon feedback is correctly accounted for, the emission metrics of non-CO2 species increase, but in most cases not as much as initially indicated by IPCC. We also find that, when the feedback is removed for both the reference and studied species, these relative metric values only have modest changes compared to when the feedback is included (absolute metrics change more markedly). Including or excluding the climate–carbon feedback ultimately depends on the user's goal, but consistency should be ensured in either case.},
author = {Gasser, Thomas and Peters, Glen P and Fuglestvedt, Jan S and Collins, William J and Shindell, Drew T and Ciais, Philippe},
doi = {10.5194/esd-8-235-2017},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {apr},
number = {2},
pages = {235--253},
title = {{Accounting for the climate–carbon feedback in emission metrics}},
url = {https://www.earth-syst-dynam.net/8/235/2017/ https://esd.copernicus.org/articles/8/235/2017/},
volume = {8},
year = {2017}
}
@article{Gasser2018,
abstract = {Emission budgets are defined as the cumulative amount of anthropogenic CO2 emission compatible with a global temperature-change target. The simplicity of the concept has made it attractive to policy-makers, yet it relies on a linear approximation of the global carbon–climate system's response to anthropogenic CO2 emissions. Here we investigate how emission budgets are impacted by the inclusion of CO2 and CH4 emissions caused by permafrost thaw, a non-linear and tipping process of the Earth system. We use the compact Earth system model OSCAR v2.2.1, in which parameterizations of permafrost thaw, soil organic matter decomposition and CO2 and CH4 emission were introduced based on four complex land surface models that specifically represent high-latitude processes. We found that permafrost carbon release makes emission budgets path dependent (that is, budgets also depend on the pathway followed to reach the target). The median remaining budget for the 2 °C target reduces by 8{\%} (1–25{\%}) if the target is avoided and net negative emissions prove feasible, by 13{\%} (2–34{\%}) if they do not prove feasible, by 16{\%} (3–44{\%}) if the target is overshot by 0.5 °C and by 25{\%} (5–63{\%}) if it is overshot by 1 °C. (Uncertainties are the minimum-to-maximum range across the permafrost models and scenarios.) For the 1.5 °C target, reductions in the median remaining budget range from {\~{}}10{\%} to more than 100{\%}. We conclude that the world is closer to exceeding the budget for the long-term target of the Paris Climate Agreement than previously thought.},
annote = {added by A. Eliseev},
author = {Gasser, T. and Kechiar, M. and Ciais, P. and Burke, E. J. and Kleinen, T. and Zhu, D. and Huang, Y. and Ekici, A. and Obersteiner, M.},
doi = {10.1038/s41561-018-0227-0},
isbn = {1752-0894 1752-0908},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {nov},
number = {11},
pages = {830--835},
pmid = {16437473},
title = {{Path-dependent reductions in CO2 emission budgets caused by permafrost carbon release}},
url = {http://www.nature.com/articles/s41561-018-0227-0},
volume = {11},
year = {2018}
}
@article{Gatti2014,
abstract = {Feedbacks between land carbon pools and climate provide one of the largest sources of uncertainty in our predictions of global climate. Estimates of the sensitivity of the terrestrial carbon budget to climate anomalies in the tropics and the identification of the mechanisms responsible for feedback effects remain uncertain. The Amazon basin stores a vast amount of carbon, and has experienced increasingly higher temperatures and more frequent floods and droughts over the past two decades. Here we report seasonal and annual carbon balances across the Amazon basin, based on carbon dioxide and carbon monoxide measurements for the anomalously dry and wet years 2010 and 2011, respectively. We find that the Amazon basin lost 0.48 ± 0.18 petagrams of carbon per year (Pg C yr-1) during the dry year but was carbon neutral (0.06 ± 0.1 Pg C yr-1) during the wet year. Taking into account carbon losses from fire by using carbon monoxide measurements, we derived the basin net biome exchange (that is, the carbon flux between the non-burned forest and the atmosphere) revealing that during the dry year, vegetation was carbon neutral. During the wet year, vegetation was a net carbon sink of 0.25 ± 0.14 Pg C yr-1, which is roughly consistent with the mean long-term intact-forest biomass sink of 0.39 ± 0.10 Pg C yr-1 previously estimated from forest censuses. Observations from Amazonian forest plots suggest the suppression of photosynthesis during drought as the primary cause for the 2010 sink neutralization. Overall, our results suggest that moisture has an important role in determining the Amazonian carbon balance. If the recent trend of increasing precipitation extremes persists, the Amazon may become an increasing carbon source as a result of both emissions from fires and the suppression of net biome exchange by drought. {\textcopyright} 2014 Macmillan Publishers Limited. All rights reserved.},
author = {Gatti, L. V. and Gloor, M. and Miller, J. B. and Doughty, C. E. and Malhi, Y. and Domingues, L. G. and Basso, L. S. and Martinewski, A. and Correia, C. S.C. and Borges, V. F. and Freitas, S. and Braz, R. and Anderson, L. O. and Rocha, H. and Grace, J. and Phillips, O. L. and Lloyd, J.},
doi = {10.1038/nature12957},
issn = {00280836},
journal = {Nature},
number = {7486},
pages = {76--80},
pmid = {24499918},
publisher = {Nature Publishing Group},
title = {{Drought sensitivity of Amazonian carbon balance revealed by atmospheric measurements}},
volume = {506},
year = {2014}
}
@article{Gattuso2018,
abstract = {The Paris agreement target of limiting global surface warming to 1.5-2°C compared to pre-industrial levels by 2100 will heavily impact the ocean. While ambitious mitigation and adaptation are both needed, the ocean provides major opportunities for action to reduce climate change globally and its impacts on vital ecosystems and ecosystem services. A comprehensive and systematic assessment of 13 global- and local-scale, ocean-based measures was performed to help steer the development and implementation of technologies and actions towards a sustainable outcome. We show that (1) all measures have tradeoffs and multiple criteria must be used for a comprehensive assessment of their potential, (2) greatest benefit is derived by combining global and local solutions, some of which could be implemented or scaled-up immediately, (3) some measures are too uncertain to be recommended yet, (4) political consistency must be achieved through effective cross-scale governance mechanisms, (5) scientific effort must focus on effectiveness, co-benefits, disbenefits, and costs of poorly tested as well as new and emerging measures.},
author = {Gattuso, Jean-Pierre and Magnan, Alexandre K and Bopp, Laurent and Cheung, William W L and Duarte, Carlos M and Hinkel, Jochen and Mcleod, Elizabeth and Micheli, Fiorenza and Oschlies, Andreas and Williamson, Phillip and Bill{\'{e}}, Rapha{\"{e}}l and Chalastani, Vasiliki I and Gates, Ruth D and Irisson, Jean-Olivier and Middelburg, Jack J and P{\"{o}}rtner, Hans-Otto and Rau, Greg H},
doi = {10.3389/fmars.2018.00337},
isbn = {2296-7745},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {oct},
pages = {337},
title = {{Ocean Solutions to Address Climate Change and Its Effects on Marine Ecosystems}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2018.00337 https://www.frontiersin.org/article/10.3389/fmars.2018.00337/full},
volume = {5},
year = {2018}
}
@article{Gattuso2015,
abstract = {The ocean moderates anthropogenic climate change at the cost of profound alterations of its physics, chemistry, ecology, and services. Here, we evaluate and compare the risks of impacts on marine and coastal ecosystems—and the goods and services they provide—for growing cumulative carbon emissions under two contrasting emissions scenarios. The current emissions trajectory would rapidly and significantly alter many ecosystems and the associated services on which humans heavily depend. A reduced emissions scenario—consistent with the Copenhagen Accord's goal of a global temperature increase of less than 2°C—is much more favorable to the ocean but still substantially alters important marine ecosystems and associated goods and services. The management options to address ocean impacts narrow as the ocean warms and acidifies. Consequently, any new climate regime that fails to minimize ocean impacts would be incomplete and inadequate.},
archivePrefix = {arXiv},
arxivId = {arXiv:1011.1669v3},
author = {Gattuso, J.-P. and Magnan, A. and Bill{\'{e}}, R. and Cheung, W. W. L. and Howes, E. L. and Joos, F. and Allemand, D. and Bopp, L. and Cooley, S. R. and Eakin, C. M. and Hoegh-Guldberg, O. and Kelly, R. P. and P{\"{o}}rtner, H.-O. and Rogers, A. D. and Baxter, J. M. and Laffoley, D. and Osborn, D. and Rankovic, A. and Rochette, J. and Sumaila, U. R. and Treyer, S. and Turley, C.},
doi = {10.1126/science.aac4722},
eprint = {arXiv:1011.1669v3},
isbn = {10.1126/science.aac4722},
issn = {0036-8075},
journal = {Science},
month = {jul},
number = {6243},
pages = {aac4722},
pmid = {26138982},
publisher = {American Association for the Advancement of Science},
title = {{Contrasting futures for ocean and society from different anthropogenic CO2 emissions scenarios}},
url = {http://www.sciencemag.org/lookup/doi/10.1126/science.aac4722 http://science.sciencemag.org/content/349/6243/aac4722},
volume = {349},
year = {2015}
}
@article{Gattuso1998,
annote = {From Duplicate 1 (Carbon and carbonate metabolism in coastal aquatic ecosystems - Gattuso, J.-P.; Frankignoulle, M; Wollast, R)

From Duplicate 2 (Carbon and carbonate metabolism in coastal aquatic ecosystems - Gattuso, J.-P.; Frankignoulle, M; Wollast, R)

OVID{\_}CC150DQ-0015; TY - Journal The coastal zone is where land, ocean, and atmosphere interact. It exhibits a wide diversity of geomorphological types and ecosystems, each one displaying great variability in terms of physical and biogeochemical forcings. Despite its relatively modest surface area, the coastal zone plays a considerable role in the biogeochemical cycles because it receives massive inputs of terrestrial organic matter and nutrients, is among the most geochemically and biologically active areas of the biosphere, and exchanges large amounts of matter and energy with the open ocean. Coastal ecosystems have therefore attracted much attention recently and are the focus of several current national and international research programs (e.g. LOICZ, ELOISE). The primary production, respiration, calcification, carbon burial and exchange with adjacent systems, including the atmosphere, are reviewed for the major coastal ecosystems (estuaries, macrophyte communities, mangroves, coral reefs, and the remaining continental shelf). All ecosystems examined, except estuaries, are net autotrophic. The contribution of the coastal zone to the global carbon cycle both during pristine times and at present is difficult to assess due to the limited metabolic data available as well as because of major uncertainties concerning the magnitude of processes such as respiration, exchanges at the open ocean boundary, and air-sea fluxes of biogases. [References: 162] English Review

From Duplicate 2 (CARBON AND CARBONATE METABOLISM IN COASTAL AQUATIC ECOSYSTEMS - Gattuso, J.-P.; Frankignoulle, M; Wollast, R)

OVID{\_}CC150DQ-0015; TY - Journal The coastal zone is where land, ocean, and atmosphere interact. It exhibits a wide diversity of geomorphological types and ecosystems, each one displaying great variability in terms of physical and biogeochemical forcings. Despite its relatively modest surface area, the coastal zone plays a considerable role in the biogeochemical cycles because it receives massive inputs of terrestrial organic matter and nutrients, is among the most geochemically and biologically active areas of the biosphere, and exchanges large amounts of matter and energy with the open ocean. Coastal ecosystems have therefore attracted much attention recently and are the focus of several current national and international research programs (e.g. LOICZ, ELOISE). The primary production, respiration, calcification, carbon burial and exchange with adjacent systems, including the atmosphere, are reviewed for the major coastal ecosystems (estuaries, macrophyte communities, mangroves, coral reefs, and the remaining continental shelf). All ecosystems examined, except estuaries, are net autotrophic. The contribution of the coastal zone to the global carbon cycle both during pristine times and at present is difficult to assess due to the limited metabolic data available as well as because of major uncertainties concerning the magnitude of processes such as respiration, exchanges at the open ocean boundary, and air-sea fluxes of biogases. [References: 162] English Review},
author = {Gattuso, J.-P. and Frankignoulle, M and Wollast, R},
doi = {10.1146/annurev.ecolsys.29.1.405},
issn = {0066-4162},
journal = {Annual Review of Ecology and Systematics},
keywords = {Calcification,Carbon cycle,Coastal ecosystems.,Community metabolism,Community metabolism.,Coral-reef,Eelgrass zostera-marina,French-polynesia,North-atlantic ocean,Organic-carbon,Papua-new-guinea,Primary production,SOLAS,Sea co2 fluxes,Seagrass posidonia-oceanica,Tropical mangrove sediments},
month = {nov},
number = {1},
pages = {405--434},
title = {{Carbon and carbonate metabolism in coastal aquatic ecosystems}},
url = {http://www.annualreviews.org/doi/10.1146/annurev.ecolsys.29.1.405 http://www.annualreviews.org/doi/abs/10.1146/annurev.ecolsys.29.1.405},
volume = {29},
year = {1998}
}
@article{Gauthier2015,
abstract = {The boreal forest, one of the largest biomes on Earth, provides ecosystem services that benefit society at levels ranging from local to global. Currently, about two-thirds of the area covered by this biome is under some form of management, mostly for wood production. Services such as climate regulation are also provided by both the unmanaged and managed boreal forests. Although most of the boreal forests have retained the resilience to cope with current disturbances, projected environmental changes of unprecedented speed and amplitude pose a substantial threat to their health. Management options to reduce these threats are available and could be implemented, but economic incentives and a greater focus on the boreal biome in international fora are needed to support further adaptation and mitigation actions.},
author = {Gauthier, S and Bernier, P and Kuuluvainen, T and Shvidenko, A Z and Schepaschenko, D G},
doi = {10.1126/science.aaa9092},
journal = {Science},
month = {aug},
number = {6250},
pages = {819--822},
title = {{Boreal forest health and global change}},
url = {http://science.sciencemag.org/content/349/6250/819.abstract},
volume = {349},
year = {2015}
}
@article{doi:10.1029/2004GL020919,
abstract = {The potential for wetland emissions to feedback on climate change has been previously hypothesised [Houghton et al., 2001]. We assess this hypothesis using an interactive wetlands scheme radiatively coupled to an integrated climate change effects model. The scheme predicts wetland area and methane (CH4) emissions from soil temperature and water table depth, and is constrained by optimising its ability to reproduce the observed inter-annual variability in atmospheric CH4. In transient climate change simulations the wetland response amplifies the total anthropogenic radiative forcing at 2100 by about 3.5–5{\%}. The modelled increase in global CH4 flux from wetland is comparable to the projected increase in anthropogenic CH4 emissions over the 21st century under the IS92a scenario.},
author = {Gedney, N. and Cox, P. M. and Huntingford, C.},
doi = {10.1029/2004GL020919},
issn = {0094-8276},
journal = {Geophysical Research Letters},
number = {20},
pages = {L20503},
title = {{Climate feedback from wetland methane emissions}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2004GL020919 http://doi.wiley.com/10.1029/2004GL020919},
volume = {31},
year = {2004}
}
@article{Gedney_2019,
abstract = {Emissions from wetlands are the single largest source of the atmospheric greenhouse gas (GHG) methane (CH4). This may increase in a warming climate, leading to a positive feedback on climate change. For the first time, we extend interactive wetland CH4 emissions schemes to include the recently quantified, significant process of CH4 transfer through tropical trees. We constrain the parameterisations using a multi-site flux study, and biogeochemical and inversion models. This provides an estimate and uncertainty range in contemporary, large-scale wetland emissions and their response to temperature. To assess the potential for future wetland CH4 emissions to feedback on climate, the schemes are forced with simulated climate change using a ‘pattern-scaling' system, which links altered atmospheric radiative forcing to meteorology changes. We perform multiple simulations emulating 34 Earth System Models over different anthropogenic GHG emissions scenarios (RCPs). We provide a detailed assessment of the causes of uncertainty in predicting wetland CH4–climate feedback. Despite the constraints applied, uncertainty from wetland CH4 emission modelling is greater that from projected climate spread (under a given RCP). Limited knowledge of contemporary global wetland emissions restricts model calibration, producing the largest individual cause of wetland parameterisation uncertainty. Wetland feedback causes an additional temperature increase between 0.6{\%} and 5.5{\%} over the 21st century, with a feedback on climate ranging from 0.01 to 0.11 Wm−2 K−1. Wetland CH4 emissions amplify atmospheric CH4 increases by up to a further possible 25.4{\%} in one simulation, and reduce remaining allowed anthropogenic emissions to maintain the RCP2.6 temperature threshold by 8.0{\%} on average.},
author = {Gedney, N and Huntingford, C and Comyn-Platt, E and Wiltshire, A},
doi = {10.1088/1748-9326/ab2726},
journal = {Environmental Research Letters},
number = {8},
pages = {84027},
publisher = {{\{}IOP{\}} Publishing},
title = {{Significant feedbacks of wetland methane release on climate change and the causes of their uncertainty}},
url = {https://doi.org/10.1088{\%}2F1748-9326{\%}2Fab2726},
volume = {14},
year = {2019}
}
@article{Genet_2013,
abstract = {There is a substantial amount of carbon stored in the permafrost soils of boreal forest ecosystems, where it is currently protected from decomposition. The surface organic horizons insulate the deeper soil from variations in atmospheric temperature. The removal of these insulating horizons through consumption by fire increases the vulnerability of permafrost to thaw, and the carbon stored in permafrost to decomposition. In this study we ask how warming and fire regime may influence spatial and temporal changes in active layer and carbon dynamics across a boreal forest landscape in interior Alaska. To address this question, we (1) developed and tested a predictive model of the effect of fire severity on soil organic horizons that depends on landscape-level conditions and (2) used this model to evaluate the long-term consequences of warming and changes in fire regime on active layer and soil carbon dynamics of black spruce forests across interior Alaska. The predictive model of fire severity, designed from the analysis of field observations, reproduces the effect of local topography (landform category, the slope angle and aspect and flow accumulation), weather conditions (drought index, soil moisture) and fire characteristics (day of year and size of the fire) on the reduction of the organic layer caused by fire. The integration of the fire severity model into an ecosystem process-based model allowed us to document the relative importance and interactions among local topography, fire regime and climate warming on active layer and soil carbon dynamics. Lowlands were more resistant to severe fires and climate warming, showing smaller increases in active layer thickness and soil carbon loss compared to drier flat uplands and slopes. In simulations that included the effects of both warming and fire at the regional scale, fire was primarily responsible for a reduction in organic layer thickness of 0.06 m on average by 2100 that led to an increase in active layer thickness of 1.1 m on average by 2100. The combination of warming and fire led to a simulated cumulative loss of 9.6 kgC m−2 on average by 2100. Our analysis suggests that ecosystem carbon storage in boreal forests in interior Alaska is particularly vulnerable, primarily due to the combustion of organic layer thickness in fire and the related increase in active layer thickness that exposes previously protected permafrost soil carbon to decomposition.},
author = {Genet, H and McGuire, A D and Barrett, K and Breen, A and Euskirchen, E S and Johnstone, J F and Kasischke, E S and Melvin, A M and Bennett, A and Mack, M C and Rupp, T S and Schuur, A E G and Turetsky, M R and Yuan, F},
doi = {10.1088/1748-9326/8/4/045016},
journal = {Environmental Research Letters},
month = {oct},
number = {4},
pages = {45016},
publisher = {{\{}IOP{\}} Publishing},
title = {{Modeling the effects of fire severity and climate warming on active layer thickness and soil carbon storage of black spruce forests across the landscape in interior Alaska}},
url = {https://doi.org/10.1088{\%}2F1748-9326{\%}2F8{\%}2F4{\%}2F045016},
volume = {8},
year = {2013}
}
@techreport{GESAMP2019,
author = {GESAMP},
editor = {Boyd, P.W. and Vivian, C.M.G},
issn = {1020-4873},
pages = {144},
publisher = {IMO/FAO/UNESCO-IOC/UNIDO/WMO/IAEA/UN/UN Environment/ UNDP/ISA Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection},
series = {Rep. Stud. GESAMP No. 98},
title = {{High Level Review of a Wide Range of Proposed Marine Geoengineering Techniques}},
url = {http://www.gesamp.org/publications/high-level-review-of-a-wide-range-of-proposed-marine-geoengineering-techniques},
year = {2019}
}
@article{Ghosh2015,
abstract = {Atmospheric methane (CH4) increased from {\~{}}900 ppb (parts per billion, or nanomoles per mole of dry air) in 1900 to {\~{}}1800 ppb in 2010 at a rate unprecedented in any observational records. However, the contributions of the various methane sources and sinks to the CH4 increase are poorly understood. Here we use initial emissions from bottom-up inventories for anthropogenic sources, emissions from wetlands and rice paddies simulated by a{\~{}}terrestrial biogeochemical model, and an atmospheric general circulation model (AGCM)-based chemistry-transport model (i.e. ACTM) to simulate atmospheric CH4 concentrations for 1910–2010. The ACTM simulations are compared with the CH4 concentration records reconstructed from Antarctic and Arctic ice cores and firn air samples, and from direct measurements since the 1980s at multiple sites around the globe. The differences between ACTM simulations and observed CH4 concentrations are minimized to optimize the global total emissions using a mass balance calculation. During 1910–2010, the global total CH4 emission doubled from {\~{}}290 to {\~{}}580 Tg yr−1. Compared to optimized emission, the bottom-up emission data set underestimates the rate of change of global total CH4 emissions by {\~{}}30{\%} during the high growth period of 1940–1990, while it overestimates by {\~{}}380{\%} during the low growth period of 1990–2010. Further, using the CH4 stable carbon isotopic data ($\delta$13C), we attribute the emission increase during 1940–1990 primarily to enhancement of biomass burning. The total lifetime of CH4 shortened from 9.4 yr during 1910–1919 to 9 yr during 2000–2009 by the combined effect of the increasing abundance of atomic chlorine radicals (Cl) and increases in average air temperature. We show that changes of CH4 loss rate due to increased tropospheric air temperature and CH4 loss due to Cl in the stratosphere are important sources of uncertainty to more accurately estimate the global CH4 budget from $\delta$13C observations.},
author = {Ghosh, A and Patra, P K and Ishijima, K and Umezawa, T and Ito, A and Etheridge, D M and Sugawara, S and Kawamura, K and Miller, J B and Dlugokencky, E J and Krummel, P B and Fraser, P J and Steele, L P and Langenfelds, R L and Trudinger, C M and White, J W C and Vaughn, B and Saeki, T and Aoki, S and Nakazawa, T},
doi = {10.5194/acp-15-2595-2015},
journal = {Atmospheric Chemistry and Physics},
number = {5},
pages = {2595--2612},
title = {{Variations in global methane sources and sinks during 1910–2010}},
url = {https://www.atmos-chem-phys.net/15/2595/2015/},
volume = {15},
year = {2015}
}
@article{Gibson2019,
abstract = {Wildfire in boreal permafrost peatlands causes a thickening and warming of the seasonally thawed active layer, exposing large amounts of soil carbon to microbial processes and potential release as greenhouse gases. In this study, conducted in the discontinuous permafrost zone of western Canada, we monitored soil thermal regime and soil respiration throughout the 2016 growing season at an unburned peat plateau and two nearby peat plateaus that burned 16 and 9 years prior to the study. Maximum seasonal soil temperature at 40 cm depth was 4 °C warmer in the burned sites, and active layers were ∼90 cm thicker compared to the unburned site. Despite the deeper and warmer seasonally thawed active layer, we found higher soil respiration in the unburned site during the first half of the growing season. We partitioned soil respiration into contribution from shallow and deep peat using a model driven by soil temperatures at 10 and 40 cm depths. Cumulative estimated deep soil respiration throughout the growing season was four times greater in the burned sites than in the unburned site, 32 and 8 g C m-2 respectively. Concurrently, cumulative shallow soil respiration was estimated to be lower in the burned than unburned site, 49 and 80 g C m-2 respectively, likely due to the removal of the microbially labile soil carbon in the shallow peat. Differences in deep contribution to soil respiration were supported by radiocarbon analysis in fall. With effects of wildfire on soil thermal regime lasting for up to 25 years in these ecosystems, we conclude that increased loss of deep, old, soil carbon during this period is of similar magnitude as the direct carbon losses from combustion during wildfire and thus needs to be considered when assessing overall impact of wildfire on carbon cycling in permafrost peatlands.},
author = {Gibson, Carolyn M. and Estop-Aragon{\'{e}}s, Cristian and Flannigan, Mike and Thompson, Dan K. and Olefeldt, David},
doi = {10.1088/1748-9326/ab4f8d},
issn = {17489326},
journal = {Environmental Research Letters},
number = {12},
pages = {125001},
title = {{Increased deep soil respiration detected despite reduced overall respiration in permafrost peat plateaus following wildfire}},
volume = {14},
year = {2019}
}
@article{Gidden2019,
author = {Gidden, Matthew J. and Riahi, Keywan and Smith, Steven J. and Fujimori, Shinichiro and Luderer, Gunnar and Kriegler, Elmar and van Vuuren, Detlef P. and van den Berg, Maarten and Feng, Leyang and Klein, David and Calvin, Katherine and Doelman, Jonathan C. and Frank, Stefan and Fricko, Oliver and Harmsen, Mathijs and Hasegawa, Tomoko and Havlik, Petr and Hilaire, J{\'{e}}r{\^{o}}me and Hoesly, Rachel and Horing, Jill and Popp, Alexander and Stehfest, Elke and Takahashi, Kiyoshi},
doi = {10.5194/gmd-12-1443-2019},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {apr},
number = {4},
pages = {1443--1475},
title = {{Global emissions pathways under different socioeconomic scenarios for use in CMIP6: a dataset of harmonized emissions trajectories through the end of the century}},
url = {https://gmd.copernicus.org/articles/12/1443/2019/},
volume = {12},
year = {2019}
}
@article{Gillett2013,
abstract = {The ratio of warming to cumulative emissions of carbon dioxide has been shown to be approximately independent of time and emissions scenarios and directly relates emissions to temperature. It is therefore a potentially important tool for climate mitigation policy. The transient climate response to cumulative carbon emissions (TCRE), defined as the ratio of global-mean warming to cumulative emissions at CO2 doubling in a 1{\%}yr21CO2 increase experiment, ranges from 0.8 to 2.4KEgC21 in 15 models from phase 5 of the Coupled Model Intercomparison Project (CMIP5)—a somewhat broader range than that found in a previous generation of carbon–climate models. Using newly available simulations and a new observational temperature dataset to 2010,TCREis estimated from observations by dividing an observationally constrained estimate of CO2-attributable warming by an estimate of cumulative carbon emissions to date, yielding an observationally constrained 5{\%}–95{\%} range of 0.7–2.0K EgC21.},
author = {Gillett, Nathan P. and Arora, Vivek K. and Matthews, Damon and Allen, Myles R.},
doi = {10.1175/JCLI-D-12-00476.1},
isbn = {10.1175/JCLI-D-12-00476.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {sep},
number = {18},
pages = {6844--6858},
title = {{Constraining the ratio of global warming to cumulative CO2 emissions using CMIP5 simulations}},
url = {http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00476.1},
volume = {26},
year = {2013}
}
@article{Gingerich2019,
author = {Gingerich, Philip D.},
doi = {10.1029/2018PA003379},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {10.1029/2018PA003379 and carbon emissions,PETM,temporal scaling},
month = {mar},
number = {3},
pages = {329--335},
title = {{Temporal Scaling of Carbon Emission and Accumulation Rates: Modern Anthropogenic Emissions Compared to Estimates of PETM Onset Accumulation}},
url = {http://doi.wiley.com/10.1029/2018PA003379 https://onlinelibrary.wiley.com/doi/abs/10.1029/2018PA003379},
volume = {34},
year = {2019}
}
@article{Gitz2003,
author = {Gitz, Vincent and Ciais, Philippe},
doi = {10.1029/2002GB001963},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {mar},
number = {1},
pages = {1--15},
title = {{Amplifying effects of land-use change on future atmospheric CO2 levels}},
url = {http://doi.wiley.com/10.1029/2002GB001963},
volume = {17},
year = {2003}
}
@article{Glienke:2015,
abstract = {Solar Radiation Management (SRM) has been proposed as a mean to partly counteract global warming. The Geoengineering Model Intercomparison Project (GeoMIP) has simulated the climate consequences of a number of SRM techniques. Thus far, the effects on vegetation have not yet been thoroughly analyzed. Here the vegetation response to the idealized GeoMIP G1 experiment from eight fully coupled Earth system models (ESMs) is analyzed, in which a reduction of the solar constant counterbalances the radiative effects of quadrupled atmospheric CO2 concentrations (abrupt4???CO2). For most models and regions, changes in net primary productivity (NPP) are dominated by the increase in CO2, via the CO2 fertilization effect. As SRM will reduce temperatures relative to abrupt4???CO2, in high latitudes this will offset increases in NPP. In low latitudes, this cooling relative to the abrupt4???CO2 simulation decreases plant respiration while having little effect on gross primary productivity, thus increasing NPP. In Central America and the Mediterranean, generally dry regions which are expected to experience increased water stress with global warming, NPP is highest in the G1 experiment for all models due to the easing of water limitations from increased water use efficiency at high-CO2 concentrations and the reduced evaporative demand in a geoengineered climate. The largest differences in the vegetation response are between models with and without a nitrogen cycle, with a much smaller CO2 fertilization effect for the former. These results suggest that until key vegetation processes are integrated into ESM predictions, the vegetation response to SRM will remain highly uncertain.},
author = {Glienke, Susanne and Irvine, Peter J and Lawrence, Mark G},
doi = {10.1002/2015JD024202},
isbn = {2169-897X},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {Earth system mode,climate engineering,vegetation},
month = {oct},
number = {19},
pages = {10196--10213},
title = {{The impact of geoengineering on vegetation in experiment G1 of the GeoMIP}},
url = {https://doi.org/10.1002/2015JD024202 http://doi.wiley.com/10.1002/2015JD024202},
volume = {120},
year = {2015}
}
@article{Gloege2020,
author = {Gloege, Lucas and McKinley, Galen A. and Landsch{\"{u}}tzer, Peter and Fay, Amanda R. and Fr{\"{o}}licher, Thomas L. and Fyfe, John C. and Ilyina, Tatiana and Jones, Steve and Lovenduski, Nicole S. and Rodgers, Keith B. and Schlunegger, Sarah and Takano, Yohei},
doi = {10.1029/2020GB006788},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
month = {apr},
number = {4},
pages = {e2020GB006788},
publisher = {Earth and Space Science Open Archive},
title = {{Quantifying Errors in Observationally Based Estimates of Ocean Carbon Sink Variability}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2020GB006788},
volume = {35},
year = {2021}
}
@article{Gloor2010a,
abstract = {The ratio of CO2 accumulating in the atmosphere to the CO2 flux into the atmosphere due to human activity, the airborne fraction AF, is central to predict changes in earth's surface temperature due to greenhouse gas induced warming. This ratio has remained remarkably constant in the past five decades, but recent studies have reported an apparent increasing trend and interpreted it as an indication for a decrease in the efficiency of the combined sinks by the ocean and terrestrial biosphere. We investigate here whether this interpretation is correct by analyzing the processes that control long-term trends and decadal-scale variations in the AF. To this end, we use simplified linear models for describing the time evolution of an atmospheric CO2 perturbation. We find firstly that the spin-up time of the system for the AF to converge to a constant value is on the order of 200ĝ€"300 years and differs depending on whether exponentially increasing fossil fuel emissions only or the sum of fossil fuel and land use emissions are used. We find secondly that the primary control on the decadal time-scale variations of the AF is variations in the relative growth rate of the total anthropogenic CO2 emissions. Changes in sink efficiencies tend to leave a smaller imprint. Therefore, before interpreting trends in the AF as an indication of weakening carbon sink efficiency, it is necessary to account for trends and variations in AF stemming from anthropogenic emissions and other extrinsic forcing events, such as volcanic eruptions. Using atmospheric CO2 data and emission estimates for the period 1959 through 2006, and our simple predictive models for the AF, we find that likely omissions in the reported emissions from land use change and extrinsic forcing events are sufficient to explain the observed long-term trend in AF. Therefore, claims for a decreasing long-term trend in the carbon sink efficiency over the last few decades are currently not supported by atmospheric CO2 data and anthropogenic emissions estimates. {\textcopyright} Author(s) 2010.},
author = {Gloor, M. and Sarmiento, J. L. and Gruber, N.},
doi = {10.5194/acp-10-7739-2010},
issn = {16807316},
journal = {Atmospheric Chemistry and Physics},
number = {16},
pages = {7739--7751},
title = {{What can be learned about carbon cycle climate feedbacks from the CO2 airborne fraction?}},
volume = {10},
year = {2010}
}
@article{bg-9-3547-2012,
abstract = {Abstract. Terrestrial carbon (C) cycle models applied for climate projections simulate a strong increase in net primary productivity (NPP) due to elevated atmospheric CO2 concentration during the 21st century. These models usually neglect the limited availability of nitrogen (N) and phosphorus (P), nutrients that commonly limit plant growth and soil carbon turnover. To investigate how the projected C sequestration is altered when stoichiometric constraints on C cycling are considered, we incorporated a P cycle into the land surface model JSBACH (Jena Scheme for Biosphere–Atmosphere Coupling in Hamburg), which already includes representations of coupled C and N cycles. The model reveals a distinct geographic pattern of P and N limitation. Under the SRES (Special Report on Emissions Scenarios) A1B scenario, the accumulated land C uptake between 1860 and 2100 is 13{\%} (particularly at high latitudes) and 16{\%} (particularly at low latitudes) lower in simulations with N and P cycling, respectively, than in simulations without nutrient cycles. The combined effect of both nutrients reduces land C uptake by 25{\%} compared to simulations without N or P cycling. Nutrient limitation in general may be biased by the model simplicity, but the ranking of limitations is robust against the parameterization and the inflexibility of stoichiometry. After 2100, increased temperature and high CO2 concentration cause a shift from N to P limitation at high latitudes, while nutrient limitation in the tropics declines. The increase in P limitation at high-latitudes is induced by a strong increase in NPP and the low P sorption capacity of soils, while a decline in tropical NPP due to high autotrophic respiration rates alleviates N and P limitations. The quantification of P limitation remains challenging. The poorly constrained processes of soil P sorption and biochemical mineralization are identified as the main uncertainties in the strength of P limitation. Even so, our findings indicate that global land C uptake in the 21st century is likely overestimated in models that neglect P and N limitations. In the long term, insufficient P availability might become an important constraint on C cycling at high latitudes. Accordingly, we argue that the P cycle must be included in global models used for C cycle projections.},
author = {Goll, D S and Brovkin, V and Parida, B R and Reick, C H and Kattge, J and Reich, P B and van Bodegom, P M and Niinemets, {\"{U}}},
doi = {10.5194/bg-9-3547-2012},
issn = {1726-4189},
journal = {Biogeosciences},
month = {sep},
number = {9},
pages = {3547--3569},
title = {{Nutrient limitation reduces land carbon uptake in simulations with a model of combined carbon, nitrogen and phosphorus cycling}},
url = {https://www.biogeosciences.net/9/3547/2012/},
volume = {9},
year = {2012}
}
@article{Goll2017,
abstract = {Abstract. Recent advances in the representation of soil carbon decomposition and carbon–nitrogen interactions implemented previously into separate versions of the land surface scheme JSBACH are here combined in a single version, which is set to be used in the upcoming 6th phase of coupled model intercomparison project (CMIP6). Here we demonstrate that the new version of JSBACH is able to reproduce the spatial variability in the reactive nitrogen-loss pathways as derived from a compilation of $\delta$15N data (R = 0. 76, root mean square error (RMSE) = 0. 2, Taylor score = 0. 83). The inclusion of carbon–nitrogen interactions leads to a moderate reduction (−10{\%}) of the carbon-concentration feedback ($\beta$L) and has a negligible effect on the sensitivity of the land carbon cycle to warming ($\gamma$L) compared to the same version of the model without carbon–nitrogen interactions in idealized simulations (1{\%} increase in atmospheric carbon dioxide per year). In line with evidence from elevated carbon dioxide manipulation experiments, pronounced nitrogen scarcity is alleviated by (1) the accumulation of nitrogen due to enhanced nitrogen inputs by biological nitrogen fixation and reduced losses by leaching and volatilization. Warming stimulated turnover of organic nitrogen further counteracts scarcity. The strengths of the land carbon feedbacks of the recent version of JSBACH, with $\beta$L = 0. 61Pg ppm−1 and $\gamma$L = −27. 5Pg °C−1, are 34 and 53{\%} less than the averages of CMIP5 models, although the CMIP5 version of JSBACH simulated $\beta$L and $\gamma$L, which are 59 and 42{\%} higher than multi-model average. These changes are primarily due to the new decomposition model, indicating the importance of soil organic matter decomposition for land carbon feedbacks.},
author = {Goll, Daniel S. and Winkler, Alexander J. and Raddatz, Thomas and Dong, Ning and Prentice, Ian Colin and Ciais, Philippe and Brovkin, Victor},
doi = {10.5194/gmd-10-2009-2017},
isbn = {1020092017},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {may},
number = {5},
pages = {2009--2030},
title = {{Carbon–nitrogen interactions in idealized simulations with JSBACH (version 3.10)}},
url = {https://www.geosci-model-dev.net/10/2009/2017/},
volume = {10},
year = {2017}
}
@article{Gonzalez2018b,
abstract = {Abstract Termination effects of large-scale artificial ocean alkalinization (AOA) have received little attention because AOA was assumed to pose low environmental risk. With the Max Planck Institute Earth system model, we use emission-driven AOA simulations following the Representative Concentration Pathway 8.5 (RCP8.5). We find that after termination of AOA warming trends in regions of the Northern Hemisphere become ?50{\%} higher than those in RCP8.5 with rates similar to those caused by termination of solar geoengineering over the following three decades after cessation (up to 0.15 K/year). Rates of ocean acidification after termination of AOA outpace those in RCP8.5. In warm shallow regions where vulnerable coral reefs are located, decreasing trends in surface pH double (0.01 units/year) and the drop in the carbonate saturation state ($\Omega$) becomes up to 1 order of magnitude larger (0.2 units/year). Thus, termination of AOA poses higher risks to biological systems sensitive to fast-paced environmental changes than previously thought.},
annote = {doi: 10.1029/2018GL077847},
author = {Gonz{\'{a}}lez, Miriam Ferrer and Ilyina, Tatiana and Sonntag, Sebastian and Schmidt, Hauke},
doi = {10.1029/2018GL077847},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Earth system modeling,artificial ocean alkalinization,geoengineering},
month = {jul},
number = {14},
pages = {7120--7129},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Enhanced rates of regional warming and ocean acidification after termination of large-scale ocean alkalinization}},
url = {https://doi.org/10.1029/2018GL077847 http://doi.wiley.com/10.1029/2018GL077847},
volume = {45},
year = {2018}
}
@article{Gonzalez-Davila2010,
author = {Gonz{\'{a}}lez-D{\'{a}}vila, M. and Santana-Casiano, J. M. and Rueda, M. J. and Llin{\'{a}}s, O.},
doi = {10.5194/bg-7-3067-2010},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {10},
pages = {3067--3081},
title = {{The water column distribution of carbonate system variables at the ESTOC site from 1995 to 2004}},
url = {http://www.biogeosciences.net/7/3067/2010/},
volume = {7},
year = {2010}
}
@article{doi:10.1175/2010JCLI3865.1,
abstract = {Abstract Future changes in atmospheric greenhouse gas concentrations, and their associated influences on climate, will affect the future sustainability of tropical forests. While dynamic global vegetation models (DGVMs) represent the processes by which climate and vegetation interact, there is limited quantitative understanding of how specific environmental drivers each affect the simulated patterns of vegetation behavior and the resultant tropical forest fraction. Here, an attempt is made to improve on the qualitative understanding of how changes in dry season length, temperature, and CO2 combine to drive forest changes. Investigation of these topics is undertaken by integrating the Hadley Centre Climate Model version 3, run at lower spatial resolution with a coupled climate–carbon cycle (HadCM3LC), to steady state. This represents the situation where vegetation has adjusted fully to the prevailing climate and vice versa, permitting direct analysis of how climate and vegetation interact. These links are quantified by fitting the simulated tropical broadleaf tree fraction with a simple function of CO2 concentration, surface temperature, and dry season length. The resulting empirical function (denoted dry season resilience or DSR) is able to predict a sustainable tropical broadleaf fraction in this model across a very wide range of climates. The DSR function can also be used to compare the importance of different environmental drivers and to explore other emissions scenarios. While this DSR function is specific to the vegetation–land surface scheme in HadCM3LC, the method employed in this work is applicable to steady-state simulations from other vegetation–land surface schemes. The DSR metric is applied first as a framework to evaluate the DGVM by comparison of the simulated and observed forest fractions. For tropical broadleaf resilience in this model, a warming of 1°C is approximately equivalent to a 2-week increase in dry season. In HadCM3LC climate model projections under the International Panel on Climate Change's (IPCC's) Special Report on Emissions Scenarios (SRES) A1B scenario, twenty-first-century increases in forest resilience due to CO2 fertilization approximately balance the tropical mean decrease from warming (the relative importance of rainfall and temperature changes depends on the uncertain spatial pattern of rainfall change). DSR is a tool that could be applied to different vegetation models to help us understand and narrow uncertainty in tropical forest projections.},
author = {Good, Peter and Jones, Chris and Lowe, Jason and Betts, Richard and Booth, Ben and Huntingford, Chris},
doi = {10.1175/2010JCLI3865.1},
journal = {Journal of Climate},
number = {5},
pages = {1337--1349},
title = {{Quantifying environmental drivers of future tropical forest extent}},
url = {https://doi.org/10.1175/2010JCLI3865.1},
volume = {24},
year = {2011}
}
@article{doi:10.1175/JCLI-D-11-00366.1,
abstract = {AbstractFuture changes in atmospheric greenhouse gas concentrations and associated influences on climate could affect the future sustainability of tropical forests. The authors report on tropical forest projections from the new Hadley Centre Global Environmental Model version 2 Earth System configuration (HadGEM2-ES) and compare them to results from the previous generation model [third climate configuration of the Met Office Unified Model in lower resolution with carbon cycle (HadCM3LC)], which had projected near-complete dieback of the Amazon rain forest for a business as usual scenario. In contrast, HadGEM2-ES projects minimal change in Amazon forest extent. The main aim of this study is a preliminary investigation of this difference between the two models. It is found that around 40{\%} of the difference in forest dieback projections is associated with differences in the projected change in dry-season length. Differences in control climatologies of temperature and dry-season length, projected regional warming, and the forest response to climate and CO2 also all contribute to the increased survival of forest in HadGEM2-ES. However, HadGEM2-ES does not invalidate HadCM3LC: Amazon dieback remains a possible scenario of dangerous change that requires further understanding. The authors discuss the relevance to assessments of dieback risk and future work toward narrowing uncertainty about the fate of the Amazon forest.},
author = {Good, Peter and Jones, Chris and Lowe, Jason and Betts, Richard and Gedney, Nicola},
doi = {10.1175/JCLI-D-11-00366.1},
journal = {Journal of Climate},
number = {2},
pages = {495--511},
title = {{Comparing tropical forest projections from two denerations of Hadley Centre Earth System Models, HadGEM2-ES and HadCM3LC}},
url = {https://doi.org/10.1175/JCLI-D-11-00366.1},
volume = {26},
year = {2013}
}
@article{Goodkin2015,
abstract = {Abstract The oceans absorb anthropogenic CO2 from the atmosphere, lowering surface ocean pH, a concern for calcifying marine organisms. The impact of ocean acidification is challenging to predict as each species appears to respond differently and because our knowledge of natural changes to ocean pH is limited in both time and space. Here we reconstruct 222?years of biennial seawater pH variability in the Sargasso Sea from a brain coral, Diploria labyrinthiformis. Using hydrographic data from the Bermuda Atlantic Time-series Study and the coral-derived pH record, we are able to differentiate pH changes due to surface temperature versus those from ocean circulation and biogeochemical changes. We find that ocean pH does not simply reflect atmospheric CO2 trends but rather that circulation/biogeochemical changes account for {\textgreater}90{\%} of pH variability in the Sargasso Sea and more variability in the last century than would be predicted from anthropogenic uptake of CO2 alone.},
annote = {doi: 10.1002/2015GL064431},
author = {Goodkin, Nathalie F and Wang, Bo-Shian and You, Chen-Feng and Hughen, Konrad A and Grumet-Prouty, Nancy and Bates, Nicholas R and Doney, Scott C},
doi = {10.1002/2015GL064431},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {AMO,Coral del11B proxy,NAO,pH},
month = {jun},
number = {12},
pages = {4931--4939},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Ocean circulation and biogeochemistry moderate interannual and decadal surface water pH changes in the Sargasso Sea}},
url = {https://doi.org/10.1002/2015GL064431 http://doi.wiley.com/10.1002/2015GL064431},
volume = {42},
year = {2015}
}
@article{Goodwin2015,
abstract = {Climate model experiments reveal that transient global warming is nearly proportional to cumulative carbon emissions on multi-decadal to centennial timescales1, 2, 3, 4, 5. However, it is not quantitatively understood how this near-linear dependence between warming and cumulative carbon emissions arises in transient climate simulations6, 7. Here, we present a theoretically derived equation of the dependence of global warming on cumulative carbon emissions over time. For an atmosphere–ocean system, our analysis identifies a surface warming response to cumulative carbon emissions of 1.5 ± 0.7 K for every 1,000 Pg of carbon emitted. This surface warming response is reduced by typically 10–20{\%} by the end of the century and beyond. The climate response remains nearly constant on multi-decadal to centennial timescales as a result of partially opposing effects of oceanic uptake of heat and carbon8. The resulting warming then becomes proportional to cumulative carbon emissions after many centuries, as noted earlier9. When we incorporate estimates of terrestrial carbon uptake10, the surface warming response is reduced to 1.1 ± 0.5 K for every 1,000 Pg of carbon emitted, but this modification is unlikely to significantly affect how the climate response changes over time. We suggest that our theoretical framework may be used to diagnose the global warming response in climate models and mechanistically understand the differences between their projections.},
author = {Goodwin, Philip and Williams, Richard G. and Ridgwell, Andy},
doi = {10.1038/ngeo2304},
isbn = {1752-0908},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jan},
number = {1},
pages = {29--34},
title = {{Sensitivity of climate to cumulative carbon emissions due to compensation of ocean heat and carbon uptake}},
url = {http://www.nature.com/articles/ngeo2304},
volume = {8},
year = {2015}
}
@article{Goodwin2018,
abstract = {To restrict global warming to below the agreed targets requires limiting carbon emissions, the principal driver of anthropogenic warming. However, there is significant uncertainty in projecting the amount of carbon that can be emitted, in part due to the limited number of Earth system model simulations and their discrepancies with present-day observations. Here we demonstrate a novel approach to reduce the uncertainty of climate projections; using theory and geological evidence we generate a very large ensemble (3 × 104) of projections that closely match records for nine key climate metrics, which include warming and ocean heat content. Our analysis narrows the uncertainty in surface-warming projections and reduces the range in equilibrium climate sensitivity. We find that a warming target of 1.5 °C above the pre-industrial level requires the total emitted carbon from the start of year 2017 to be less than 195–205 PgC (in over 66{\%} of the simulations), whereas a warming target of 2 °C is only likely if the emitted carbon remains less than 395–455 PgC. At the current emission rates, these warming targets are reached in 17–18 years and 35–41 years, respectively, so that there is a limited window to develop a more carbon-efficient future.},
author = {Goodwin, Philip and Katavouta, Anna and Roussenov, Vassil M and Foster, Gavin L and Rohling, Eelco J and Williams, Richard G},
doi = {10.1038/s41561-017-0054-8},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {feb},
number = {2},
pages = {102--107},
title = {{Pathways to 1.5 °C and 2 °C warming based on observational and geological constraints}},
url = {https://doi.org/10.1038/s41561-017-0054-8 http://www.nature.com/articles/s41561-017-0054-8},
volume = {11},
year = {2018}
}
@article{Gottschalk2019,
author = {Gottschalk, Julia and Battaglia, Gianna and Fischer, Hubertus and Fr{\"{o}}licher, Thomas L. and Jaccard, Samuel L. and Jeltsch-Th{\"{o}}mmes, Aurich and Joos, Fortunat and K{\"{o}}hler, Peter and Meissner, Katrin J. and Menviel, Laurie and Nehrbass-Ahles, Christoph and Schmitt, Jochen and Schmittner, Andreas and Skinner, Luke C. and Stocker, Thomas F.},
doi = {10.1016/j.quascirev.2019.05.013},
issn = {02773791},
journal = {Quaternary Science Reviews},
month = {sep},
pages = {30--74},
title = {{Mechanisms of millennial-scale atmospheric CO2 change in numerical model simulations}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0277379118310473},
volume = {220},
year = {2019}
}
@article{Gottschalk2020,
author = {Gottschalk, Julia and Michel, Elisabeth and Th{\"{o}}le, Lena M and Studer, Anja S and Hasenfratz, Adam P and Schmid, Nicole and Butzin, Martin and Mazaud, Alain and Mart{\'{i}}nez-Garc{\'{i}}a, Alfredo and Szidat, S{\"{o}}nke and Jaccard, Samuel L},
doi = {10.1038/s41467-020-20034-1},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {6192},
title = {{Glacial heterogeneity in Southern Ocean carbon storage abated by fast South Indian deglacial carbon release}},
url = {https://doi.org/10.1038/s41467-020-20034-1},
volume = {11},
year = {2020}
}
@article{Gottschalk2020a,
abstract = {Past millennial-scale changes in atmospheric CO2 (CO2,atm) concentrations have often been attributed to variations in the overturning timescale of the ocean that result in changes in the marine carbon inventory. Yet, there remains a paucity of proxy evidence that documents changes in marine carbon storage globally, and that links them to abrupt climate variability in the northern hemisphere associated with perturbations of the Atlantic Meridional Overturning Circulation (AMOC). The last two glacial periods were suggested to differ in the spatial extent of the AMOC and its sensitivity to perturbations. This provides an opportunity to compare the nature of marine carbon cycle-climate feedbacks between them. Here, we reconstruct variations in respired carbon storage (via oxygenation) and the AMOC “geometry” (via carbonate ion saturation) in the deep South Atlantic. We infer decreases in deep South Atlantic respired carbon levels at times of weakened AMOC and rising CO2,atm concentrations during both glacial periods. These findings suggest a consistent pattern of increased Southern Ocean convection and/or air-sea CO2 fluxes during northern-hemisphere stadials accompanying AMOC perturbations and promoting a rise in CO2,atm levels. We find that net ocean carbon loss, and hence the magnitude of CO2,atm rise, is largely determined by the stadial duration. North Atlantic climate anomalies therefore affect Southern Ocean carbon cycling in a consistent manner, through oceanic (e.g., ventilation seesaw) and/or atmospheric processes (e.g., Ekman pumping).},
author = {Gottschalk, Julia and Skinner, Luke C and Jaccard, Samuel L and Menviel, Laurie and Nehrbass-Ahles, Christoph and Waelbroeck, Claire},
doi = {10.1016/j.quascirev.2019.106067},
issn = {0277-3791},
journal = {Quaternary Science Reviews},
keywords = {Atmospheric CO variations,Carbon cycle,Dansgaard-Oeschger cycles,Foraminifera,Glacials,Interstadials,Palaeoclimatology,Redox-sensitive elements,Southern Ocean,Stadials},
pages = {106067},
title = {{Southern Ocean link between changes in atmospheric CO2 levels and northern-hemisphere climate anomalies during the last two glacial periods}},
url = {http://www.sciencedirect.com/science/article/pii/S0277379118310461},
volume = {230},
year = {2020}
}
@article{Gottschalk2016,
abstract = {Millennial-scale climate changes during the last glacial period and deglaciation were accompanied by rapid changes in atmospheric CO2 that remain unexplained. While the role of the Southern Ocean as a 'control valve' on ocean-atmosphere CO2 exchange has been emphasized, the exact nature of this role, in particular the relative contributions of physical (for example, ocean dynamics and air-sea gas exchange) versus biological processes (for example, export productivity), remains poorly constrained. Here we combine reconstructions of bottom-water [O2], export production and (14)C ventilation ages in the sub-Antarctic Atlantic, and show that atmospheric CO2 pulses during the last glacial- and deglacial periods were consistently accompanied by decreases in the biological export of carbon and increases in deep-ocean ventilation via southern-sourced water masses. These findings demonstrate how the Southern Ocean's 'organic carbon pump' has exerted a tight control on atmospheric CO2, and thus global climate, specifically via a synergy of both physical and biological processes.},
author = {Gottschalk, Julia and Skinner, Luke C. and Lippold, J{\"{o}}rg and Vogel, Hendrik and Frank, Norbert and Jaccard, Samuel L. and Waelbroeck, Claire},
doi = {10.1038/ncomms11539},
isbn = {2041-1723 (Electronic)$\backslash$r2041-1723 (Linking)},
issn = {2041-1723},
journal = {Nature Communications},
month = {sep},
number = {1},
pages = {11539},
pmid = {27187527},
title = {{Biological and physical controls in the Southern Ocean on past millennial-scale atmospheric CO2 changes}},
url = {http://www.nature.com/articles/ncomms11539},
volume = {7},
year = {2016}
}
@article{Grassi2018,
author = {Grassi, Giacomo and House, Jo and Kurz, Werner A. and Cescatti, Alessandro and Houghton, Richard A. and Peters, Glen P. and Sanz, Maria J. and Vi{\~{n}}as, Raul Abad and Alkama, Ramdane and Arneth, Almut and Bondeau, Alberte and Dentener, Frank and Fader, Marianela and Federici, Sandro and Friedlingstein, Pierre and Jain, Atul K. and Kato, Etsushi and Koven, Charles D. and Lee, Donna and Nabel, Julia E. M. S. and Nassikas, Alexander A. and Perugini, Lucia and Rossi, Simone and Sitch, Stephen and Viovy, Nicolas and Wiltshire, Andy and Zaehle, S{\"{o}}nke},
doi = {10.1038/s41558-018-0283-x},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {oct},
number = {10},
pages = {914--920},
publisher = {Springer US},
title = {{Reconciling global-model estimates and country reporting of anthropogenic forest CO2 sinks}},
url = {http://www.nature.com/articles/s41558-018-0283-x},
volume = {8},
year = {2018}
}
@article{RN638,
abstract = {Abstract. The isotopic composition of carbon ($\Delta$14C and $\delta$13C) in atmospheric CO2 and in oceanic and terrestrial carbon reservoirs is influenced by anthropogenic emissions and by natural carbon exchanges, which can respond to and drive changes in climate. Simulations of 14C and 13C in the ocean and terrestrial components of Earth system models (ESMs) present opportunities for model evaluation and for investigation of carbon cycling, including anthropogenic CO2 emissions and uptake. The use of carbon isotopes in novel evaluation of the ESMs' component ocean and terrestrial biosphere models and in new analyses of historical changes may improve predictions of future changes in the carbon cycle and climate system. We compile existing data to produce records of $\Delta$14C and $\delta$13C in atmospheric CO2 for the historical period 1850–2015. The primary motivation for this compilation is to provide the atmospheric boundary condition for historical simulations in the Coupled Model Intercomparison Project 6 (CMIP6) for models simulating carbon isotopes in the ocean or terrestrial biosphere. The data may also be useful for other carbon cycle modelling activities.},
author = {Graven, Heather D and Allison, Colin E and Etheridge, David M and Hammer, Samuel and Keeling, Ralph F and Levin, Ingeborg and Meijer, Harro A J and Rubino, Mauro and Tans, Pieter P and Trudinger, Cathy M and Vaughn, Bruce H and White, James W C},
doi = {10.5194/gmd-10-4405-2017},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {dec},
number = {12},
pages = {4405--4417},
title = {{Compiled records of carbon isotopes in atmospheric CO2 for historical simulations in CMIP6}},
type = {Journal Article},
url = {https://www.geosci-model-dev.net/10/4405/2017/},
volume = {10},
year = {2017}
}
@article{Graven2013,
abstract = {Seasonal variations of atmospheric carbon dioxide (CO 2 ) in the Northern Hemisphere have increased since the 1950s, but sparse observations have prevented a clear assessment of the patterns of long-term change and the underlying mechanisms. We compare recent aircraft-based observations of CO 2 above the North Pacific and Arctic Oceans to earlier data from 1958 to 1961 and find that the seasonal amplitude at altitudes of 3 to 6 km increased by 50{\%} for 45° to 90°N but by less than 25{\%} for 10° to 45°N. An increase of 30 to 60{\%} in the seasonal exchange of CO 2 by northern extratropical land ecosystems, focused on boreal forests, is implicated, substantially more than simulated by current land ecosystem models. The observations appear to signal large ecological changes in northern forests and a major shift in the global carbon cycle.},
archivePrefix = {arXiv},
arxivId = {1504.04694},
author = {Graven, H. D. and Keeling, R. F. and Piper, S. C. and Patra, P. K. and Stephens, B. B. and Wofsy, S. C. and Welp, L. R. and Sweeney, C. and Tans, P. P. and Kelley, J. J. and Daube, B. C. and Kort, E. A. and Santoni, G. W. and Bent, J. D.},
doi = {10.1126/science.1239207},
eprint = {1504.04694},
isbn = {1095-9203 (Electronic)$\backslash$r0036-8075 (Linking)},
issn = {0036-8075},
journal = {Science},
month = {sep},
number = {6150},
pages = {1085--1089},
pmid = {23929948},
publisher = {American Association for the Advancement of Science},
title = {{Enhanced Seasonal Exchange of CO2 by Northern Ecosystems Since 1960}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1239207 https://www.sciencemag.org/lookup/doi/10.1126/science.1239207},
volume = {341},
year = {2013}
}
@article{Green2019,
abstract = {Although the terrestrial biosphere absorbs about 25 per cent of anthropogenic carbon dioxide (CO2) emissions, the rate of land carbon uptake remains highly uncertain, leading to uncertainties in climate projections1,2. Understanding the factors that limit or drive land carbon storage is therefore important for improving climate predictions. One potential limiting factor for land carbon uptake is soil moisture, which can reduce gross primary production through ecosystem water stress3,4, cause vegetation mortality5 and further exacerbate climate extremes due to land–atmosphere feedbacks6. Previous work has explored the impact of soil-moisture availability on past carbon-flux variability3,7,8. However, the influence of soil-moisture variability and trends on the long-term carbon sink and the mechanisms responsible for associated carbon losses remain uncertain. Here we use the data output from four Earth system models9 from a series of experiments to analyse the responses of terrestrial net biome productivity to soil-moisture changes, and find that soil-moisture variability and trends induce large CO2 fluxes (about two to three gigatons of carbon per year; comparable with the land carbon sink itself1) throughout the twenty-first century. Subseasonal and interannual soil-moisture variability generate CO2 as a result of the nonlinear response of photosynthesis and net ecosystem exchange to soil-water availability and of the increased temperature and vapour pressure deficit caused by land–atmosphere interactions. Soil-moisture variability reduces the present land carbon sink, and its increase and drying trends in several regions are expected to reduce it further. Our results emphasize that the capacity of continents to act as a future carbon sink critically depends on the nonlinear response of carbon fluxes to soil moisture and on land–atmosphere interactions. This suggests that the increasing trend in carbon uptake rate may not be sustained past the middle of the century and could result in accelerated atmospheric CO2 growth.},
author = {Green, Julia K. and Seneviratne, Sonia I. and Berg, Alexis M. and Findell, Kirsten L. and Hagemann, Stefan and Lawrence, David M. and Gentine, Pierre},
doi = {10.1038/s41586-018-0848-x},
issn = {14764687},
journal = {Nature},
number = {7740},
pages = {476--479},
pmid = {30675043},
publisher = {Springer US},
title = {{Large influence of soil moisture on long-term terrestrial carbon uptake}},
volume = {565},
year = {2019}
}
@article{Gregor2018,
abstract = {Abstract. Resolving and understanding the drivers of variability of CO2 in the Southern Ocean and its potential climate feedback is one of the major scientific challenges of the ocean-climate community. Here we use a regional approach on empirical estimates of pCO2 to understand the role that seasonal variability has in long-term CO2 changes in the Southern Ocean. Machine learning has become the preferred empirical modelling tool to interpolate time- and location-restricted ship measurements of pCO2. In this study we use an ensemble of three machine-learning products: support vector regression (SVR) and random forest regression (RFR) from Gregor et al. (2017), and the self-organising-map feed-forward neural network (SOM-FFN) method from Landsch{\"{u}}tzer et al. (2016). The interpolated estimates of $\Delta$pCO2 are separated into nine regions in the Southern Ocean defined by basin (Indian, Pacific, and Atlantic) and biomes (as defined by Fay and McKinley, 2014a). The regional approach shows that, while there is good agreement in the overall trend of the products, there are periods and regions where the confidence in estimated $\Delta$pCO2 is low due to disagreement between the products. The regional breakdown of the data highlighted the seasonal decoupling of the modes for summer and winter interannual variability. Winter interannual variability had a longer mode of variability compared to summer, which varied on a 4–6-year timescale. We separate the analysis of the $\Delta$pCO2 and its drivers into summer and winter. We find that understanding the variability of $\Delta$pCO2 and its drivers on shorter timescales is critical to resolving the long-term variability of $\Delta$pCO2. Results show that $\Delta$pCO2 is rarely driven by thermodynamics during winter, but rather by mixing and stratification due to the stronger correlation of $\Delta$pCO2 variability with mixed layer depth. Summer pCO2 variability is consistent with chlorophyll a variability, where higher concentrations of chlorophyll a correspond with lower pCO2 concentrations. In regions of low chlorophyll a concentrations, wind stress and sea surface temperature emerged as stronger drivers of $\Delta$pCO2. In summary we propose that sub-decadal variability is explained by summer drivers, while winter variability contributes to the long-term changes associated with the SAM. This approach is a useful framework to assess the drivers of $\Delta$pCO2 but would greatly benefit from improved estimates of $\Delta$pCO2 and a longer time series.},
author = {Gregor, Luke and Kok, Schalk and Monteiro, Pedro M. S.},
doi = {10.5194/bg-15-2361-2018},
issn = {1726-4189},
journal = {Biogeosciences},
month = {apr},
number = {8},
pages = {2361--2378},
title = {{Interannual drivers of the seasonal cycle of CO2 in the Southern Ocean}},
url = {https://www.biogeosciences.net/15/2361/2018/},
volume = {15},
year = {2018}
}
@article{Gregor2019a,
author = {Gregor, Luke and Lebehot, Alice D. and Kok, Schalk and {Scheel Monteiro}, Pedro M.},
doi = {10.5194/gmd-12-5113-2019},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {dec},
number = {12},
pages = {5113--5136},
title = {{A comparative assessment of the uncertainties of global surface ocean CO2 estimates using a machine-learning ensemble (CSIR-ML6 version 2019a) – have we hit the wall?}},
url = {https://gmd.copernicus.org/articles/12/5113/2019/ https://www.geosci-model-dev.net/12/5113/2019/},
volume = {12},
year = {2019}
}
@article{Gregory2009,
abstract = {Abstract Perturbations to the carbon cycle could constitute large feedbacks on future changes in atmospheric CO2 concentration and climate. This paper demonstrates how carbon cycle feedback can be expressed in formally similar ways to climate feedback, and thus compares their magnitudes. The carbon cycle gives rise to two climate feedback terms: the concentration–carbon feedback, resulting from the uptake of carbon by land and ocean as a biogeochemical response to the atmospheric CO2 concentration, and the climate–carbon feedback, resulting from the effect of climate change on carbon fluxes. In the earth system models of the Coupled Climate–Carbon Cycle Model Intercomparison Project (C4MIP), climate–carbon feedback on warming is positive and of a similar size to the cloud feedback. The concentration–carbon feedback is negative; it has generally received less attention in the literature, but in magnitude it is 4 times larger than the climate–carbon feedback and more uncertain. The concentration–carbon feed...},
archivePrefix = {arXiv},
arxivId = {arXiv:1011.1669v3},
author = {Gregory, J. M. and Jones, C. D. and Cadule, P. and Friedlingstein, P.},
doi = {10.1175/2009JCLI2949.1},
eprint = {arXiv:1011.1669v3},
isbn = {0894-8755},
issn = {0894-8755},
journal = {Journal of Climate},
month = {oct},
number = {19},
pages = {5232--5250},
pmid = {11089968},
title = {{Quantifying Carbon Cycle Feedbacks}},
url = {http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2949.1},
volume = {22},
year = {2009}
}
@article{Gregory2015,
abstract = {In the Coupled Model Intercomparison Project Phase 5 (CMIP5), the model-mean increase in global mean surface air temperature T under the 1pctCO2 scenario (atmospheric CO2 increasing at 1 yr1) durin...},
author = {Gregory, J. M. and Andrews, T. and Good, P.},
doi = {10.1098/rsta.2014.0417},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
keywords = {climate change,climate modelling,climate sensitivity,ocean heat uptake,radiative forcing},
month = {nov},
number = {2054},
pages = {20140417},
publisher = {The Royal Society Publishing},
title = {{The inconstancy of the transient climate response parameter under increasing CO2}},
url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2014.0417},
volume = {373},
year = {2015}
}
@article{Griscom2020,
abstract = {Better land stewardship is needed to achieve the Paris Agreement's temperature goal, particularly in the tropics, where greenhouse gas emissions from the destruction of ecosystems are largest, and where the potential for additional land carbon storage is greatest. As countries enhance their nationally determined contributions (NDCs) to the Paris Agreement, confusion persists about the potential contribution of better land stewardship to meeting the Agreement's goal to hold global warming below 2°C. We assess cost-effective tropical country-level potential of natural climate solutions (NCS)—protection, improved management and restoration of ecosystems—to deliver climate mitigation linked with sustainable development goals (SDGs). We identify groups of countries with distinctive NCS portfolios, and we explore factors (governance, financial capacity) influencing the feasibility of unlocking national NCS potential. Cost-effective tropical NCS offers globally significant climate mitigation in the coming decades (6.56 Pg CO 2 e yr −1 at less than 100 US{\$} per Mg CO 2 e). In half of the tropical countries, cost-effective NCS could mitigate over half of national emissions. In more than a quarter of tropical countries, cost-effective NCS potential is greater than national emissions. We identify countries where, with international financing and political will, NCS can cost-effectively deliver the majority of enhanced NDCs while transforming national economies and contributing to SDGs.},
author = {Griscom, Bronson W. and Busch, Jonah and Cook-Patton, Susan C. and Ellis, Peter W. and Funk, Jason and Leavitt, Sara M. and Lomax, Guy and Turner, Will R. and Chapman, Melissa and Engelmann, Jens and Gurwick, Noel P. and Landis, Emily and Lawrence, Deborah and Malhi, Yadvinder and {Schindler Murray}, Lisa and Navarrete, Diego and Roe, Stephanie and Scull, Sabrina and Smith, Pete and Streck, Charlotte and Walker, Wayne S. and Worthington, Thomas},
doi = {10.1098/rstb.2019.0126},
issn = {0962-8436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
month = {mar},
number = {1794},
pages = {20190126},
title = {{National mitigation potential from natural climate solutions in the tropics}},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0126},
volume = {375},
year = {2020}
}
@article{Griscom2017,
abstract = {Better stewardship of land is needed to achieve the Paris Climate Agreement goal of holding warming to below 2 °C; however, confusion persists about the specific set of land stewardship options available and their mitigation potential. To address this, we identify and quantify “natural climate solutions” (NCS): 20 conservation, restoration, and improved land management actions that increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, and agricultural lands. We find that the maximum potential of NCS—when constrained by food security, fiber security, and biodiversity conservation—is 23.8 petagrams of CO 2 equivalent (PgCO 2 e) y −1 (95{\%} CI 20.3–37.4). This is ≥30{\%} higher than prior estimates, which did not include the full range of options and safeguards considered here. About half of this maximum (11.3 PgCO 2 e y −1 ) represents cost-effective climate mitigation, assuming the social cost of CO 2 pollution is ≥100 USD MgCO 2 e −1 by 2030. Natural climate solutions can provide 37{\%} of cost-effective CO 2 mitigation needed through 2030 for a {\textgreater}66{\%} chance of holding warming to below 2 °C. One-third of this cost-effective NCS mitigation can be delivered at or below 10 USD MgCO 2 −1 . Most NCS actions—if effectively implemented—also offer water filtration, flood buffering, soil health, biodiversity habitat, and enhanced climate resilience. Work remains to better constrain uncertainty of NCS mitigation estimates. Nevertheless, existing knowledge reported here provides a robust basis for immediate global action to improve ecosystem stewardship as a major solution to climate change.},
author = {Griscom, Bronson W. and Adams, Justin and Ellis, Peter W. and Houghton, Richard A. and Lomax, Guy and Miteva, Daniela A. and Schlesinger, William H. and Shoch, David and Siikam{\"{a}}ki, Juha V. and Smith, Pete and Woodbury, Peter and Zganjar, Chris and Blackman, Allen and Campari, Jo{\~{a}}o and Conant, Richard T. and Delgado, Christopher and Elias, Patricia and Gopalakrishna, Trisha and Hamsik, Marisa R. and Herrero, Mario and Kiesecker, Joseph and Landis, Emily and Laestadius, Lars and Leavitt, Sara M. and Minnemeyer, Susan and Polasky, Stephen and Potapov, Peter and Putz, Francis E. and Sanderman, Jonathan and Silvius, Marcel and Wollenberg, Eva and Fargione, Joseph},
doi = {10.1073/pnas.1710465114},
isbn = {0027-8424},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
language = {en},
month = {oct},
number = {44},
pages = {11645--11650},
pmid = {29078344},
title = {{Natural climate solutions}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1710465114},
volume = {114},
year = {2017}
}
@article{Gromov2018,
author = {Gromov, Sergey and Brenninkmeijer, Carl A. M. and J{\"{o}}ckel, Patrick},
doi = {10.5194/acp-18-9831-2018},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {jul},
number = {13},
pages = {9831--9843},
title = {{A very limited role of tropospheric chlorine as a sink of the greenhouse gas methane}},
url = {https://acp.copernicus.org/articles/18/9831/2018/},
volume = {18},
year = {2018}
}
@article{doi:10.1111/nph.16485,
abstract = {Summary Recent decades have been characterized by increasing temperatures worldwide, resulting in an exponential climb in vapor pressure deficit (VPD). VPD has been identified as an increasingly important driver of plant functioning in terrestrial biomes and has been established as a major contributor in recent drought-induced plant mortality independent of other drivers associated with climate change. Despite this, few studies have isolated the physiological response of plant functioning to high VPD, thus limiting our understanding and ability to predict future impacts on terrestrial ecosystems. An abundance of evidence suggests that stomatal conductance declines under high VPD and transpiration increases in most species up until a given VPD threshold, leading to a cascade of subsequent impacts including reduced photosynthesis and growth, and higher risks of carbon starvation and hydraulic failure. Incorporation of photosynthetic and hydraulic traits in ‘next-generation' land-surface models has the greatest potential for improved prediction of VPD responses at the plant- and global-scale, and will yield more mechanistic simulations of plant responses to a changing climate. By providing a fully integrated framework and evaluation of the impacts of high VPD on plant function, improvements in forecasting and long-term projections of climate impacts can be made.},
author = {Grossiord, Charlotte and Buckley, Thomas N and Cernusak, Lucas A and Novick, Kimberly A and Poulter, Benjamin and Siegwolf, Rolf T W and Sperry, John S and McDowell, Nate G},
doi = {10.1111/nph.16485},
journal = {New Phytologist},
keywords = {mortality,productivity,stomatal conductance,transpiration,warming},
number = {6},
pages = {1550--1566},
title = {{Plant responses to rising vapor pressure deficit}},
url = {https://nph.onlinelibrary.wiley.com/doi/abs/10.1111/nph.16485},
volume = {226},
year = {2020}
}
@article{Gruber2008,
abstract = {With humans having an increasing impact on the planet, the interactions between the nitrogen cycle, the carbon cycle and climate are expected to become an increasingly important determinant of the Earth system.},
author = {Gruber, Nicolas and Galloway, James N},
doi = {10.1038/nature06592},
issn = {0028-0836},
journal = {Nature},
month = {jan},
number = {7176},
pages = {293--296},
publisher = {Nature Publishing Group},
title = {{An Earth-system perspective of the global nitrogen cycle}},
url = {http://dx.doi.org/10.1038/nature06592 http://www.nature.com/doifinder/10.1038/nature06592},
volume = {451},
year = {2008}
}
@article{Gruber2011,
abstract = {In the coming decades and centuries, the ocean's biogeochemical cycles and ecosystems will become increasingly stressed by at least three independent factors. Rising temperatures, ocean acidification and ocean deoxygenation will cause substantial changes in the physical, chemical and biological environment, which will then affect the ocean's biogeochemical cycles and ecosystems in ways that we are only beginning to fathom. Ocean warming will not only affect organisms and biogeochemical cycles directly, but will also increase upper ocean stratification. The changes in the ocean's carbonate chemistry induced by the uptake of anthropogenic carbon dioxide (CO2) (i.e. ocean acidification) will probably affect many organisms and processes, although in ways that are currently not well understood. Ocean deoxygenation, i.e. the loss of dissolved oxygen (O2) from the ocean, is bound to occur in a warming and more stratified ocean, causing stress to macro-organisms that critically depend on sufficient levels of oxygen. These three stressors—warming, acidification and deoxygenation—will tend to operate globally, although with distinct regional differences. The impacts of ocean acidification tend to be strongest in the high latitudes, whereas the low-oxygen regions of the low latitudes are most vulnerable to ocean deoxygenation. Specific regions, such as the eastern boundary upwelling systems, will be strongly affected by all three stressors, making them potential hotspots for change. Of additional concern are synergistic effects, such as ocean acidification-induced changes in the type and magnitude of the organic matter exported to the ocean's interior, which then might cause substantial changes in the oxygen concentration there. Ocean warming, acidification and deoxygenation are essentially irreversible on centennial time scales, i.e. once these changes have occurred, it will take centuries for the ocean to recover. With the emission of CO2 being the primary driver behind all three stressors, the primary mitigation strategy is to reduce these emissions.},
author = {Gruber, Nicolas},
doi = {10.1098/rsta.2011.0003},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {may},
number = {1943},
pages = {1980--1996},
title = {{Warming up, turning sour, losing breath: ocean biogeochemistry under global change}},
url = {http://rsta.royalsocietypublishing.org/content/369/1943/1980.abstract http://rsta.royalsocietypublishing.org/cgi/doi/10.1098/rsta.2011.0003},
volume = {369},
year = {2011}
}
@article{Gruber2019b,
abstract = {The CO2 uptake by the Southern Ocean ({\textless}35°S) varies substantially on all timescales and is a major determinant of the variations of the global ocean carbon sink. Particularly strong are the decadal changes characterized by a weakening period of the Southern Ocean carbon sink in the 1990s and a rebound after 2000. The weakening in the 1990s resulted primarily from a southward shift of the westerlies that enhanced the upwelling and outgassing of respired (i.e., natural) CO2. The concurrent reduction in the storage rate of anthropogenic CO2 in the mode and intermediate waters south of 35°S suggests that this shift also decreased the uptake of anthropogenic CO2. The rebound and the subsequent strong, decade-long reinvigoration of the carbon sink appear to have been driven by cooling in the Pacific Ocean, enhanced stratification in the Atlantic and Indian Ocean sectors, and a reduced overturning. Current-generation ocean models generally do not reproduce these variations and are poorly skilled at making decada...},
author = {Gruber, Nicolas and Landsch{\"{u}}tzer, Peter and Lovenduski, Nicole S.},
doi = {10.1146/annurev-marine-121916-063407},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {159--186},
publisher = {Annual Reviews 4139 El Camino Way, PO Box 10139, Palo Alto, California 94303-0139, USA},
title = {{The variable Southern Ocean carbon sink}},
url = {https://www.annualreviews.org/doi/10.1146/annurev-marine-121916-063407},
volume = {11},
year = {2019}
}
@article{Gruber2019d,
abstract = {We quantify the oceanic sink for anthropogenic carbon dioxide (CO 2 ) over the period 1994 to 2007 by using observations from the global repeat hydrography program and contrasting them to observations from the 1990s. Using a linear regression–based method, we find a global increase in the anthropogenic CO 2 inventory of 34 ± 4 petagrams of carbon (Pg C) between 1994 and 2007. This is equivalent to an average uptake rate of 2.6 ± 0.3 Pg C year −1 and represents 31 ± 4{\%} of the global anthropogenic CO 2 emissions over this period. Although this global ocean sink estimate is consistent with the expectation of the ocean uptake having increased in proportion to the rise in atmospheric CO 2 , substantial regional differences in storage rate are found, likely owing to climate variability–driven changes in ocean circulation.},
author = {Gruber, Nicolas and Clement, Dominic and Carter, Brendan R. and Feely, Richard A. and van Heuven, Steven and Hoppema, Mario and Ishii, Masao and Key, Robert M. and Kozyr, Alex and Lauvset, Siv K. and {Lo Monaco}, Claire and Mathis, Jeremy T. and Murata, Akihiko and Olsen, Are and Perez, Fiz F. and Sabine, Christopher L. and Tanhua, Toste and Wanninkhof, Rik},
doi = {10.1126/science.aau5153},
issn = {0036-8075},
journal = {Science},
month = {mar},
number = {6432},
pages = {1193--1199},
pmid = {30872519},
publisher = {American Association for the Advancement of Science},
title = {{The oceanic sink for anthropogenic CO2 from 1994 to 2007}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.aau5153},
volume = {363},
year = {2019}
}
@article{GU2017371,
author = {Gu, Jiangxin and Yuan, Mengxuan and Liu, Jixuan and Hao, Yaoxu and Zhou, Yingtian and Qu, Dong and Yang, Xueyun},
doi = {10.1016/j.scitotenv.2017.03.280},
issn = {00489697},
journal = {Science of The Total Environment},
keywords = {Agricultural soil,Global warming potential,Greenhouse gas mitigation,NO,Organic amendment,SOC},
month = {oct},
pages = {371--379},
title = {{Trade-off between soil organic carbon sequestration and nitrous oxide emissions from winter wheat-summer maize rotations: Implications of a 25-year fertilization experiment in Northwestern China}},
url = {http://www.sciencedirect.com/science/article/pii/S0048969717308112 https://linkinghub.elsevier.com/retrieve/pii/S0048969717308112},
volume = {595},
year = {2017}
}
@article{Guanter2014,
abstract = {Photosynthesis is the process by which plants harvest sunlight to produce sugars from carbon dioxide and water. It is the primary source of energy for all life on Earth; hence it is important to understand how this process responds to climate change and human impact. However, model-based estimates of gross primary production (GPP, output from photosynthesis) are highly uncertain, in particular over heavily managed agricultural areas. Recent advances in spectroscopy enable the space-based monitoring of sun-induced chlorophyll fluorescence (SIF) from terrestrial plants. Here we demonstrate that spaceborne SIF retrievals provide a direct measure of the GPP of cropland and grassland ecosystems. Such a strong link with crop photosynthesis is not evident for traditional remotely sensed vegetation indices, nor for more complex carbon cycle models. We use SIF observations to provide a global perspective on agricultural productivity. Our SIF-based crop GPP estimates are 50-75{\%} higher than results from state-of-the-art carbon cycle models over, for example, the US Corn Belt and the Indo-Gangetic Plain, implying that current models severely underestimate the role of management. Our results indicate that SIF data can help us improve our global models for more accurate projections of agricultural productivity and climate impact on crop yields. Extension of our approach to other ecosystems, along with increased observational capabilities for SIF in the near future, holds the prospect of reducing uncertainties in the modeling of the current and future carbon cycle.},
author = {Guanter, L. and Zhang, Y. and Jung, M. and Joiner, J. and Voigt, M. and Berry, J. A. and Frankenberg, C. and Huete, A. R. and Zarco-Tejada, P. and Lee, J.-E. and Moran, M. S. and Ponce-Campos, G. and Beer, C. and Camps-Valls, G. and Buchmann, N. and Gianelle, D. and Klumpp, K. and Cescatti, A. and Baker, J. M. and Griffis, T. J.},
doi = {10.1073/pnas.1320008111},
isbn = {0027-8424},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {apr},
number = {14},
pages = {E1327--E1333},
pmid = {24706867},
title = {{Global and time-resolved monitoring of crop photosynthesis with chlorophyll fluorescence}},
url = {http://www.pnas.org/content/111/14/E1327 http://www.pnas.org/cgi/doi/10.1073/pnas.1320008111},
volume = {111},
year = {2014}
}
@article{Guenet2018a,
abstract = {Abstract Fresh carbon input (above and belowground) contributes to soil carbon sequestration, but also accelerates decomposition of soil organic matter through biological priming mechanisms. Currently, poor understanding precludes the incorporation of these priming mechanisms into the global carbon models used for future projections. Here, we show that priming can be incorporated based on a simple equation calibrated from incubation and verified against independent litter manipulation experiments in the global land surface model, ORCHIDEE. When incorporated into ORCHIDEE, priming improved the model's representation of global soil carbon stocks and decreased soil carbon sequestration by 51{\%} (12 {\$}\backslashpm{\$}3 Pg C) during the period 1901?2010. Future projections with the same model across the range of CO2 and climate changes defined by the IPCC-RCP scenarios reveal that priming buffers the projected changes in soil carbon stocks ? both the increases due to enhanced productivity and new input to the soil, and the decreases due to warming-induced accelerated decomposition. Including priming in Earth system models leads to different projections of soil carbon changes, which are challenging to verify at large spatial scales.},
author = {Guenet, Bertrand and Camino-Serrano, Marta and Ciais, Philippe and Tifafi, Marwa and Maignan, Fabienne and Soong, Jennifer L and Janssens, Ivan A},
doi = {10.1111/gcb.14069},
isbn = {1354-1013},
issn = {13541013},
journal = {Global Change Biology},
month = {may},
number = {5},
pages = {1873--1883},
title = {{Impact of priming on global soil carbon stocks}},
url = {http://doi.wiley.com/10.1111/gcb.14069},
volume = {24},
year = {2018}
}
@article{Guerrieri2019,
abstract = {Multiple lines of evidence suggest that plant water-use efficiency (WUE)—the ratio of carbon assimilation to water loss—has increased in recent decades. Although rising atmospheric CO2 has been proposed as the principal cause, the underlying physiological mechanisms are still being debated, and implications for the global water cycle remain uncertain. Here, we addressed this gap using 30-y tree ring records of carbon and oxygen isotope measurements and basal area increment from 12 species in 8 North American mature temperate forests. Our goal was to separate the contributions of enhanced photosynthesis and reduced stomatal conductance to WUE trends and to assess consistency between multiple commonly used methods for estimating WUE. Our results show that tree ring-derived estimates of increases in WUE are consistent with estimates from atmospheric measurements and predictions based on an optimal balancing of carbon gains and water costs, but are lower than those based on ecosystem-scale flux observations. Although both physiological mechanisms contributed to rising WUE, enhanced photosynthesis was widespread, while reductions in stomatal conductance were modest and restricted to species that experienced moisture limitations. This finding challenges the hypothesis that rising WUE in forests is primarily the result of widespread, CO2-induced reductions in stomatal conductance.},
author = {Guerrieri, Rossella and Belmecheri, Soumaya and Ollinger, Scott V. and Asbjornsen, Heidi and Jennings, Katie and Xiao, Jingfeng and Stocker, Benjamin D. and Martin, Mary and Hollinger, David Y. and Bracho-Garrillo, Rosvel and Clark, Kenneth and Dore, Sabina and Kolb, Thomas and {William Munger}, J. and Novick, Kimberly and Richardson, Andrew D.},
doi = {10.1073/pnas.1905912116},
issn = {10916490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {AmeriFlux,CO2 fertilization,Stable isotopes,Tree rings,Water-use efficiency},
number = {34},
pages = {16909--16914},
pmid = {31383758},
title = {{Disentangling the role of photosynthesis and stomatal conductance on rising forest water-use efficiency}},
volume = {116},
year = {2019}
}
@article{Guidi2009,
author = {Guidi, Lionel and Stemmann, Lars and Jackson, George A. and Ibanez, Fr{\'{e}}d{\'{e}}ric and Claustre, Herv{\'{e}} and Legendre, Louis and Picheral, Marc and Gorskya, Gabriel},
doi = {10.4319/lo.2009.54.6.1951},
issn = {00243590},
journal = {Limnology and Oceanography},
month = {nov},
number = {6},
pages = {1951--1963},
title = {{Effects of phytoplankton community on production, size, and export of large aggregates: A world-ocean analysis}},
url = {http://doi.wiley.com/10.4319/lo.2009.54.6.1951},
volume = {54},
year = {2009}
}
@article{Guimberteau2018,
abstract = {Abstract. The high-latitude regions of the Northern Hemisphere are a nexus for the interaction between land surface physical properties and their exchange of carbon and energy with the atmosphere. At these latitudes, two carbon pools of planetary significance – those of the permanently frozen soils (permafrost), and of the great expanse of boreal forest – are vulnerable to destabilization in the face of currently observed climatic warming, the speed and intensity of which are expected to increase with time. Improved projections of future Arctic and boreal ecosystem transformation require improved land surface models that integrate processes specific to these cold biomes. To this end, this study lays out relevant new parameterizations in the ORCHIDEE-MICT land surface model. These describe the interactions between soil carbon, soil temperature and hydrology, and their resulting feedbacks on water and CO2 fluxes, in addition to a recently developed fire module. Outputs from ORCHIDEE-MICT, when forced by two climate input datasets, are extensively evaluated against (i) temperature gradients between the atmosphere and deep soils, (ii) the hydrological components comprising the water balance of the largest high-latitude basins, and (iii) CO2 flux and carbon stock observations. The model performance is good with respect to empirical data, despite a simulated excessive plant water stress and a positive land surface temperature bias. In addition, acute model sensitivity to the choice of input forcing data suggests that the calibration of model parameters is strongly forcing-dependent. Overall, we suggest that this new model design is at the forefront of current efforts to reliably estimate future perturbations to the high-latitude terrestrial environment.},
author = {Guimberteau, Matthieu and Zhu, Dan and Maignan, Fabienne and Huang, Ye and Yue, Chao and Dantec-N{\'{e}}d{\'{e}}lec, Sarah and Ottl{\'{e}}, Catherine and Jornet-Puig, Albert and Bastos, Ana and Laurent, Pierre and Goll, Daniel and Bowring, Simon and Chang, Jinfeng and Guenet, Bertrand and Tifafi, Marwa and Peng, Shushi and Krinner, Gerhard and Ducharne, Agn{\`{e}}s and Wang, Fuxing and Wang, Tao and Wang, Xuhui and Wang, Yilong and Yin, Zun and Lauerwald, Ronny and Joetzjer, Emilie and Qiu, Chunjing and Kim, Hyungjun and Ciais, Philippe},
doi = {10.5194/gmd-11-121-2018},
isbn = {1991-9603},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {jan},
number = {1},
pages = {121--163},
title = {{ORCHIDEE-MICT (v8.4.1), a land surface model for the high latitudes: model description and validation}},
url = {https://www.geosci-model-dev.net/11/121/2018/},
volume = {11},
year = {2018}
}
@article{Gupta2016,
abstract = {Observations along 10 shelf transects in 2012 near 10°N in the southeastern Arabian Sea revealed the usual warm oligotrophic conditions during the winter monsoon and upwelling of oxygen-deficient, nutrient-rich cool water during the summer monsoon (SM). By changing an oligotrophic to a nutrient-replete condition, the upwelling is the major process that regulates the biogeochemistry of this shelf. Its onset is perceptible at 100 m depth between January and March. The upwelling reaches the surface layer in May and intensifies during June–July but withdraws completely and abruptly by October. Despite the nutrient injection, the primary production during SM, integrated for euphotic zone, is comparable to that during the preceding spring intermonsoon (SIM). Again, as usual, the high oxygen demand coupled with low concentration in the upwelled subsurface waters causes severe oxygen depletion below the shallow pycnocline. The oxygen concentrations/saturations of 2012 on the midshelf are similar from those of mid-1958 to early 1960, except for marginally higher values during the peak upwelling period due to relatively weak upwelling in 2012. This implies little anthropogenic influence on coastal hypoxia unlike many other coastal regions. In 2012, the inner shelf system shifted from net autotrophy in SIM to net heterotrophy in SM but on an annual basis it was net autotrophic (gross primary production to community respiration ratio, GPP/R:1.11 ± 0.84) as organic production exceeded consumption.},
author = {Gupta, G V M and Sudheesh, V and Sudharma, K V and Saravanane, N and Dhanya, V. and Dhanya, K R and Lakshmi, G and Sudhakar, M and Naqvi, S W A},
doi = {10.1002/2015JG003163},
issn = {21698953},
journal = {Journal of Geophysical Research: Biogeosciences},
keywords = {0404 Anoxic and hypoxic environments,4273 Physical and biogeochemical interactions,4277 Time series experiments,4279 Upwelling and convergences,4853 Photosynthesis,biogeochemistry,dissolved oxygen,nutrients,primary production respiration,trophic status,upwelling},
month = {jan},
number = {1},
pages = {159--175},
title = {{Evolution to decay of upwelling and associated biogeochemistry over the southeastern Arabian Sea shelf}},
url = {http://dx.doi.org/10.1002/2015JG003163 http://doi.wiley.com/10.1002/2015JG003163},
volume = {121},
year = {2016}
}
@article{Gutjahr2017,
abstract = {The PalaeoceneEocene Thermal Maximum was a surface warming event associated with ecological disruption that occurred about 56 million years ago. A large amount of carbon is thought to have been released during this event, but the total amount and the sources of carbon remain uncertain. This paper combines boron and carbon isotope data in an Earth system model and finds that the source of carbon was much larger than previously thought and that most of the carbon was probably released by volcanism associated with the North Atlantic Igneous Province. The study also suggests that the amplifying organic carbonclimate feedbacks did not have a prominent role in driving the event, but that enhanced burial of organic matter was important for sequestering the released carbon and accelerating the recovery of the climate system.},
author = {Gutjahr, Marcus and Ridgwell, Andy and Sexton, Philip F. and Anagnostou, Eleni and Pearson, Paul N. and P{\"{a}}like, Heiko and Norris, Richard D. and Thomas, Ellen and Foster, Gavin L.},
doi = {10.1038/nature23646},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7669},
pages = {573--577},
pmid = {28858305},
title = {{Very large release of mostly volcanic carbon during the Palaeocene–Eocene Thermal Maximum}},
url = {http://www.nature.com/doifinder/10.1038/nature23646 http://www.nature.com/articles/nature23646},
volume = {548},
year = {2017}
}
@article{Hoglund-Isaksson2020,
author = {H{\"{o}}glund-Isaksson, Lena and G{\'{o}}mez-Sanabria, Adriana and Klimont, Zbigniew and Rafaj, Peter and Sch{\"{o}}pp, Wolfgang},
doi = {10.1088/2515-7620/ab7457},
issn = {2515-7620},
journal = {Environmental Research Communications},
month = {feb},
number = {2},
pages = {025004},
title = {{Technical potentials and costs for reducing global anthropogenic methane emissions in the 2050 timeframe – results from the GAINS model}},
url = {https://iopscience.iop.org/article/10.1088/2515-7620/ab7457},
volume = {2},
year = {2020}
}
@article{Honisch2005,
abstract = {Knowledge of past atmospheric pCO 2 is important for evaluating the role of greenhouse gases in climate forcing. Ice core records show the tight correlation between climate change and pCO 2 , but records are limited to the past {\~{}}900 kyr. We present surface ocean pH and PCO 2 data, reconstructed from boron isotopes in planktonic foraminifera over two full glacial cycles (0-140 and 300-420 kyr). The data co-vary strongly with the Vostok pCO 2-record and demonstrate that the coupling between surface ocean chemistry and the atmosphere is recorded in marine archives, allowing for quantitative estimation of atmospheric pCO 2 beyond the reach of ice cores.},
author = {H{\"{o}}nisch, B{\"{a}}rbel and Hemming, N. Gary},
doi = {10.1016/j.epsl.2005.04.027},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {boron isotopes,pCO 2,pH,planktonic foraminifera},
month = {jul},
number = {1-2},
pages = {305--314},
title = {{Surface ocean pH response to variations in pCO2 through two full glacial cycles}},
url = {www.elsevier.com/locate/epsl https://linkinghub.elsevier.com/retrieve/pii/S0012821X05002803},
volume = {236},
year = {2005}
}
@article{Hain2010,
abstract = {In a box model synthesis of Southern Ocean and North Atlantic mechanisms for lowering CO2 during ice ages, the CO2 changes are parsed into their component geochemical causes, including the soft-tissue pump, the carbonate pump, and whole ocean alkalinity. When the mechanisms are applied together, their interactions greatly modify the net CO2 change. Combining the Antarctic mechanisms (stratification, nutrient drawdown, and sea ice cover) within bounds set by observations decreases CO2 by no more than 36 ppm, a drawdown that could be caused by any one of these mechanisms in isolation. However, these Antarctic changes reverse the CO2 effect of the observed ice age shoaling of North Atlantic overturning: in isolation, the shoaling raises CO2 by 16 ppm, but alongside the Antarctic changes, it lowers CO2 by an additional 13 ppm, a 29 ppm synergy. The total CO2 decrease does not reach 80 ppm, partly because Antarctic stratification, Antarctic sea ice cover, and the shoaling of North Atlantic overturning all strengthen the sequestration of alkalinity in the deepest ocean, which increases CO2 both by itself and by decreasing whole ocean alkalinity. Increased nutrient consumption in the sub-Antarctic causes as much as an additional 35 ppm CO2 decrease, interacting minimally with the other changes. With its inclusion, the lowest ice age CO2 levels are within reach. These findings may bear on the two-stepped CO2 decrease of the last ice age.},
author = {Hain, Mathis P. and Sigman, Daniel M. and Haug, Gerald H.},
doi = {10.1029/2010GB003790},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {dec},
number = {4},
pages = {GB4023},
title = {{Carbon dioxide effects of Antarctic stratification, North Atlantic Intermediate Water formation, and subantarctic nutrient drawdown during the last ice age: Diagnosis and synthesis in a geochemical box model}},
url = {http://doi.wiley.com/10.1029/2010GB003790},
volume = {24},
year = {2010}
}
@article{Hajima2014,
abstract = {AbstractCarbon uptake by land and ocean as a biogeochemical response to increasing atmospheric CO2 concentration is called concentration?carbon feedback and is one of the carbon cycle feedbacks of the global climate. This feedback can have a major impact on climate projections with an uncertain magnitude. This paper focuses on the concentration?carbon feedback in terrestrial ecosystems, analyzing the mechanisms and strength of the feedback reproduced by Earth system models (ESMs) participating in phase 5 of the Coupled Model Intercomparison Project. It is confirmed that multiple ESMs driven by a common scenario show a large spread of concentration?carbon feedback strength among models. Examining the behavior of the carbon fluxes and pools of the models showed that the sensitivity of plant productivity to elevated CO2 is likely the key to reduce the spread, although increasing CO2 stimulates other carbon cycle processes. Simulations with a single ESM driven by different CO2 pathways demonstrated that carbon accumulation increases in scenarios with slower CO2 increase rates. Using both numerical and analytical approaches, the study showed that the difference among CO2 scenarios is a time lag of terrestrial carbon pools in response to atmospheric CO2 increase?a high rate of CO2 increase results in smaller carbon accumulations than that in an equilibrium state of a given CO2 concentration. These results demonstrate that the current quantities for concentration?carbon feedback are incapable of capturing the feedback dependency on the carbon storage state and suggest that the concentration feedback can be larger for future scenarios where the CO2 growth rate is reduced.},
annote = {doi: 10.1175/JCLI-D-13-00177.1},
author = {Hajima, Tomohiro and Tachiiri, Kaoru and Ito, Akihiko and Kawamiya, Michio},
doi = {10.1175/JCLI-D-13-00177.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {may},
number = {9},
pages = {3425--3445},
publisher = {American Meteorological Society},
title = {{Uncertainty of concentration–terrestrial carbon feedback in Earth System Models}},
url = {https://doi.org/10.1175/JCLI-D-13-00177.1 http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-13-00177.1},
volume = {27},
year = {2014}
}
@article{Hajima2020c,
abstract = {Earth system models (ESMs) are commonly used for simulating the climate–carbon (C) cycle and for projecting future global warming. While ESMs are most often applied to century-long climate simulations, millennium-long simulations, which have been conducted by other types of models but not by ESM because of the computational cost, can provide basic fundamental properties of climate–C cycle models and will be required for estimating the carbon dioxide (CO2) concentration and subsequent climate stabilization in the future. This study used two ESMs (the Model for Interdisciplinary Research on Climate, the Earth system model version (MIROC-ESM) and the MIROC Earth system version 2 for long-term simulation (MIROC-ES2L)) to investigate millennium-scale climate and C cycle adjustment to external forcing. The CO2 concentration was doubled abruptly at the beginning of the model simulations and kept at that level for the next 1000 or 2000 years; these model simulations were compared with transient simulations where the CO2 was increased at the rate of 1{\%} year−1 for up to 140 years (1pctCO2). Model simulations to separate and evaluate the C cycle feedbacks were also performed. Unlike the 1pctCO2 experiment, the change in temperature–cumulative anthropogenic C emission (∆T–CE) relationship was non-linear over the millennium time-scales; there were differences in this nonlinearity between the two ESMs. The differences in ∆T–CE among existing models suggest large uncertainty in the ∆T and CE in the millennium-long climate-C simulations. Ocean C and heat transport were found to be disconnected over millennium time-scales, leading to longer time-scale of ocean C accumulation than heat uptake. Although the experimental design used here was highly idealized, this long-lasting C uptake by the ocean should be considered as part of the stabilization of CO2 concentration and global warming. Future studies should perform millennium time-scale simulations using a hierarchy of models to clarify climate-C cycle processes and to understand the long-term response of the Earth system to anthropogenic perturbations. [Figure not available: see fulltext.].},
author = {Hajima, Tomohiro and Yamamoto, Akitomo and Kawamiya, Michio and Su, Xuanming and Watanabe, Michio and Ohgaito, Rumi and Tatebe, Hiroaki},
doi = {10.1186/s40645-020-00350-2},
issn = {21974284},
journal = {Progress in Earth and Planetary Science},
keywords = {Carbon cycle feedbacks, Transient climate response to cumulative carbon emission, Anthropogenic emission,Earth system models,Global warming,Millennium time-scales},
month = {dec},
number = {1},
pages = {1--19},
publisher = {Springer},
title = {{Millennium time-scale experiments on climate-carbon cycle with doubled CO2 concentration}},
url = {https://link.springer.com/articles/10.1186/s40645-020-00350-2 https://link.springer.com/article/10.1186/s40645-020-00350-2},
volume = {7},
year = {2020}
}
@article{Hajima2020,
author = {Hajima, Tomohiro and Watanabe, Michio and Yamamoto, Akitomo and Tatebe, Hiroaki and Noguchi, Maki A. and Abe, Manabu and Ohgaito, Rumi and Ito, Akinori and Yamazaki, Dai and Okajima, Hideki and Ito, Akihiko and Takata, Kumiko and Ogochi, Koji and Watanabe, Shingo and Kawamiya, Michio},
doi = {10.5194/gmd-13-2197-2020},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {may},
number = {5},
pages = {2197--2244},
title = {{Development of the MIROC-ES2L Earth system model and the evaluation of biogeochemical processes and feedbacks}},
url = {https://gmd.copernicus.org/articles/13/2197/2020/},
volume = {13},
year = {2020}
}
@article{Hall2007,
author = {Hall, B. D. and Dutton, G. S. and Elkins, J. W.},
doi = {10.1029/2006JD007954},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Atmospheres},
month = {may},
number = {D9},
pages = {D09305},
title = {{The NOAA nitrous oxide standard scale for atmospheric observations}},
url = {http://doi.wiley.com/10.1029/2006JD007954},
volume = {112},
year = {2007}
}
@article{Hall2019a,
abstract = {In recent years, an evaluation technique for Earth System Models (ESMs) has arisen—emergent constraints (ECs)—which rely on strong statistical relationships between aspects of current climate and future change across an ESM ensemble. Combining the EC relationship with observations could reduce uncertainty surrounding future change. Here, we articulate a framework to assess ECs, and provide indicators whereby a proposed EC may move from a strong statistical relationship to confirmation. The primary indicators are verified mechanisms and out-of-sample testing. Confirmed ECs have the potential to improve ESMs by focusing attention on the variables most relevant to climate projections. Looking forward, there may be undiscovered ECs for extremes and teleconnections, and ECs may help identify climate system tipping points.},
author = {Hall, Alex and Cox, Peter and Huntingford, Chris and Klein, Stephen},
doi = {10.1038/s41558-019-0436-6},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {apr},
number = {4},
pages = {269--278},
title = {{Progressing emergent constraints on future climate change}},
url = {http://www.nature.com/articles/s41558-019-0436-6},
volume = {9},
year = {2019}
}
@article{Hamilton2018,
author = {Hamilton, Stuart E. and Friess, Daniel A.},
doi = {10.1038/s41558-018-0090-4},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {mar},
number = {3},
pages = {240--244},
title = {{Global carbon stocks and potential emissions due to mangrove deforestation from 2000 to 2012}},
url = {http://www.nature.com/articles/s41558-018-0090-4},
volume = {8},
year = {2018}
}
@article{Hansell2009a,
abstract = {Containing as much carbon as the atmosphere, marine dissolved organic matter is one of Earth's major carbon reservoirs. With invigoration of scientific inquiries into the global carbon cycle, our ignorance of its role in ocean biogeochemistry became untenable. Rapid mobilization of relevant research two decades ago required the community to overcome early false leads, but subsequent progress in examining the global dynamics of this material has been steady. Continuous improvements in analytical skill coupled with global ocean hydrographic survey opportunities resulted in the generation of thousands of measurements throughout the major ocean basins. Here, observations and model results provide new insights into the large-scale variability of dissolved organic carbon, its contribution to the biological pump, and its deep ocean sinks.},
author = {Hansell, Dennis A. and Carlson, Craig A. and Repeta, Daniel J. and Schlitzer, Reiner},
doi = {10.5670/oceanog.2009.109},
issn = {10428275},
journal = {Oceanography},
month = {dec},
number = {4},
pages = {202--211},
title = {{Dissolved Organic Matter in the Ocean: A Controversy Stimulates New Insights}},
url = {https://tos.org/oceanography/article/dissolved-organic-matter-in-the-ocean-a-controversy-stimulates-new-insights},
volume = {22},
year = {2009}
}
@article{Hansis2015,
author = {Hansis, Eberhard and Davis, Steven J. and Pongratz, Julia},
doi = {10.1002/2014GB004997},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {Attribution,Bookkeeping model of land use emissions,Carbon flux accounting,Global carbon cycle,Land use and land cover change,Net land use flux},
month = {aug},
number = {8},
pages = {1230--1246},
title = {{Relevance of methodological choices for accounting of land use change carbon fluxes}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2014GB004997},
volume = {29},
year = {2015}
}
@article{gmd-13-3299-2020,
author = {Hantson, S and Kelley, D I and Arneth, A and Harrison, S P and Archibald, S and Bachelet, D and Forrest, M and Hickler, T and Lasslop, G and Li, F and Mangeon, S and Melton, J R and Nieradzik, L and Rabin, S S and Prentice, I C and Sheehan, T and Sitch, S and Teckentrup, L and Voulgarakis, A and Yue, C},
doi = {10.5194/gmd-13-3299-2020},
journal = {Geoscientific Model Development},
number = {7},
pages = {3299--3318},
title = {{Quantitative assessment of fire and vegetation properties in simulations with fire-enabled vegetation models from the Fire Model Intercomparison Project}},
url = {https://gmd.copernicus.org/articles/13/3299/2020/},
volume = {13},
year = {2020}
}
@incollection{Harenda2018a,
abstract = {Peatlands are unique habitats that are covering around 3{\%} of the land area and they are characterized by high sensitivity to climate. These very complex ecosystems impact both water and carbon cycle at local as well as global scale. Peatlands are also valuable ecosystems due to their mitigating features in terms of floods or soil erosion and they can store and filtrate water in the landscape as well. As a result of high moisture they can also gather a big amount of carbon and this ability makes peatlands climate coolers. On the other hand a stored carbon can be released into the atmosphere due to peat moisture decrease and it accelerate the global warming processes. Beside climate changes, peatlands are under pressure that is caused by human activities like land use changes or fires. Peatlands protection and restoration can both mitigate climate changes and water balance disturbances. A review of peatlands status and feature in the context of climate changes and human-induced disturbances are presented in this paper.},
address = {Cham, Switzerland},
author = {Harenda, Kamila M. and Lamentowicz, Mariusz and Samson, Mateusz and Chojnicki, Bogdan H.},
booktitle = {Interdisciplinary Approaches for Sustainable Development Goals: Economic Growth, Social Inclusion and Environmental Protection},
doi = {10.1007/978-3-319-71788-3_12},
editor = {Zielinski, Tymon and Sagan, Iwona and Surosz, Waldemar},
issn = {21905207},
pages = {169--187},
publisher = {Springer},
title = {{The role of peatlands and their carbon storage function in the context of climate change}},
year = {2018}
}
@article{Harper2018,
abstract = {Scenarios that limit global warming to below 2 °C by 2100 assume significant land-use change to support large-scale carbon dioxide (CO2) removal from the atmosphere by afforestation/reforestation, avoided deforestation, and Biomass Energy with Carbon Capture and Storage (BECCS). The more ambitious mitigation scenarios require even greater land area for mitigation and/or earlier adoption of CO2 removal strategies. Here we show that additional land-use change to meet a 1.5 °C climate change target could result in net losses of carbon from the land. The effectiveness of BECCS strongly depends on several assumptions related to the choice of biomass, the fate of initial above ground biomass, and the fossil-fuel emissions offset in the energy system. Depending on these factors, carbon removed from the atmosphere through BECCS could easily be offset by losses due to land-use change. If BECCS involves replacing high-carbon content ecosystems with crops, then forest-based mitigation could be more efficient for atmospheric CO2 removal than BECCS.},
author = {Harper, Anna B. and Powell, Tom and Cox, Peter M. and House, Joanna and Huntingford, Chris and Lenton, Timothy M. and Sitch, Stephen and Burke, Eleanor and Chadburn, Sarah E. and Collins, William J. and Comyn-Platt, Edward and Daioglou, Vassilis and Doelman, Jonathan C. and Hayman, Garry and Robertson, Eddy and van Vuuren, Detlef and Wiltshire, Andy and Webber, Christopher P. and Bastos, Ana and Boysen, Lena and Ciais, Philippe and Devaraju, Narayanappa and Jain, Atul K. and Krause, Andreas and Poulter, Ben and Shu, Shijie},
doi = {10.1038/s41467-018-05340-z},
isbn = {4146701805},
issn = {2041-1723},
journal = {Nature Communications},
language = {en},
month = {dec},
number = {1},
pages = {2938},
pmid = {30087330},
title = {{Land-use emissions play a critical role in land-based mitigation for Paris climate targets}},
url = {http://www.nature.com/articles/s41467-018-05340-z},
volume = {9},
year = {2018}
}
@article{Harris2014a,
abstract = {This paper describes the construction of an updated gridded climate dataset (referred to as CRU TS3.10) from monthly observations at meteorological stations across the world's land areas. Station anomalies (from 1961 to 1990 means) were interpolated into 0.5° latitude/longitude grid cells covering the global land surface (excluding Antarctica), and combined with an existing climatology to obtain absolute monthly values. The dataset includes six mostly independent climate variables (mean temperature, diurnal temperature range, precipitation, wet-day frequency, vapour pressure and cloud cover). Maximum and minimum temperatures have been arithmetically derived from these. Secondary variables (frost day frequency and potential evapotranspiration) have been estimated from the six primary variables using well-known formulae. Time series for hemispheric averages and 20 large sub-continental scale regions were calculated (for mean, maximum and minimum temperature and precipitation totals) and compared to a number of similar gridded products. The new dataset compares very favourably, with the major deviations mostly in regions and/or time periods with sparser observational data. CRU TS3.10 includes diagnostics associated with each interpolated value that indicates the number of stations used in the interpolation, allowing determination of the reliability of values in an objective way. This gridded product will be publicly available, including the input station series (http://www.cru.uea.ac.uk/ and http://badc.nerc.ac.uk/data/cru/). {\textcopyright} 2013 Royal Meteorological Society},
author = {Harris, I. and Jones, P.D. and Osborn, T.J. and Lister, D.H.},
doi = {10.1002/joc.3711},
isbn = {1097-0088},
issn = {08998418},
journal = {International Journal of Climatology},
keywords = {Gridded climate data,High resolution,Precipitation,Temperature},
month = {mar},
number = {3},
pages = {623--642},
pmid = {16338704},
title = {{Updated high-resolution grids of monthly climatic observations – the CRU TS3.10 Dataset}},
url = {http://doi.wiley.com/10.1002/joc.3711},
volume = {34},
year = {2014}
}
@article{Harrison2018,
abstract = {Abstract. Temperature exerts strong controls on the incidence and severity of fire. All else equal, warming is expected to increase fire-related carbon emissions, and thereby atmospheric CO2. But the magnitude of this feedback is very poorly known. We use a single-box model of the land biosphere to quantify this positive feedback from satellite-based estimates of biomass burning emissions for 2000–2014CE and from sedimentary charcoal records for the millennium before the industrial period. We derive an estimate of the centennial-scale feedback strength of 6.5±3.4ppmCO2 per degree of land temperature increase, based on the satellite data. However, this estimate is poorly constrained, and is largely driven by the well-documented dependence of tropical deforestation and peat fires (primarily anthropogenic) on climate variability patterns linked to the El Ni{\~{n}}o–Southern Oscillation. Palaeo-data from pre-industrial times provide the opportunity to assess the fire-related climate–carbon-cycle feedback over a longer period, with less pervasive human impacts. Past biomass burning can be quantified based on variations in either the concentration and isotopic composition of methane in ice cores (with assumptions about the isotopic signatures of different methane sources) or the abundances of charcoal preserved in sediments, which reflect landscape-scale changes in burnt biomass. These two data sources are shown here to be coherent with one another. The more numerous data from sedimentary charcoal, expressed as normalized anomalies (fractional deviations from the long-term mean), are then used – together with an estimate of mean biomass burning derived from methane isotope data – to infer a feedback strength of 5.6±3.2ppmCO2 per degree of land temperature and (for a climate sensitivity of 2.8K) a gain of 0.09±0.05. This finding indicates that the positive carbon cycle feedback from increased fire provides a substantial contribution to the overall climate–carbon-cycle feedback on centennial timescales. Although the feedback estimates from palaeo- and satellite-era data are in agreement, this is likely fortuitous because of the pervasive influence of human activities on fire regimes during recent decades.},
author = {Harrison, Sandy P. and Bartlein, Patrick J. and Brovkin, Victor and Houweling, Sander and Kloster, Silvia and Prentice, I. Colin},
doi = {10.5194/esd-9-663-2018},
isbn = {2190-4987},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {may},
number = {2},
pages = {663--677},
title = {{The biomass burning contribution to climate–carbon-cycle feedback}},
url = {https://www.earth-syst-dynam.net/9/663/2018/},
volume = {9},
year = {2018}
}
@article{Hartmann2013b,
abstract = {Chemical weathering is an integral part of both the rock and carbon cycles and is being affected by changes in land use, particularly as a result of agricultural practices such as tilling, mineral fertilization, or liming to adjust soil pH. These human activities have already altered the terrestrial chemical cycles and land‐ocean flux of major elements, although the extent remains difficult to quantify. When deployed on a grand scale, Enhanced Weathering (a form of mineral fertilization), the application of finely ground minerals over the land surface, could be used to remove CO2 from the atmosphere. The release of cations during the dissolution of such silicate minerals would convert dissolved CO2 to bicarbonate, increasing the alkalinity and pH of natural waters. Some products of mineral dissolution would precipitate in soils or be taken up by ecosystems, but a significant portion would be transported to the coastal zone and the open ocean, where the increase in alkalinity would partially counteract “ocean acidification” associated with the current marked increase in atmospheric CO2. Other elements released during this mineral dissolution, like Si, P, or K, could stimulate biological productivity, further helping to remove CO2 from the atmosphere. On land, the terrestrial carbon pool would likely increase in response to Enhanced Weathering in areas where ecosystem growth rates are currently limited by one of the nutrients that would be released during mineral dissolution. In the ocean, the biological carbon pumps (which export organic matter and CaCO3 to the deep ocean) may be altered by the resulting influx of nutrients and alkalinity to the ocean. This review merges current interdisciplinary knowledge about Enhanced Weathering, the processes involved, and the applicability as well as some of the consequences and risks of applying the method.},
author = {Hartmann, Jens and West, A. Joshua and Renforth, Phil and K{\"{o}}hler, Peter and {De La Rocha}, Christina L. and Wolf-Gladrow, Dieter A. and D{\"{u}}rr, Hans H. and Scheffran, J{\"{u}}rgen},
doi = {10.1002/rog.20004},
issn = {87551209},
journal = {Reviews of Geophysics},
month = {apr},
number = {2},
pages = {113--149},
title = {{Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification}},
url = {http://dx.doi.org/10.1002/rog.20004 http://doi.wiley.com/10.1002/rog.20004},
volume = {51},
year = {2013}
}
@article{Hasenclever2017,
abstract = {Paleo-climate records and geodynamic modelling indicate the existence of complex interactions between glacial sea level changes, volcanic degassing and atmospheric CO2, which may have modulated the climate system's descent into the last ice age. Between ∼85 and 70 kyr ago, during an interval of decreasing axial tilt, the orbital component in global temperature records gradually declined, while atmospheric CO2, instead of continuing its long-term correlation with Antarctic temperature, remained relatively stable. Here, based on novel global geodynamic models and the joint interpretation of paleo-proxy data as well as biogeochemical simulations, we show that a sea level fall in this interval caused enhanced pressure-release melting in the uppermost mantle, which may have induced a surge in magma and CO2 fluxes from mid-ocean ridges and oceanic hotspot volcanoes. Our results reveal a hitherto unrecognized negative feedback between glaciation and atmospheric CO2 predominantly controlled by marine volcanism on multi-millennial timescales of ∼5,000-15,000 years.},
author = {Hasenclever, J{\"{o}}rg and Knorr, Gregor and R{\"{u}}pke, Lars H. and K{\"{o}}hler, Peter and Morgan, Jason and Garofalo, Kristin and Barker, Stephen and Lohmann, Gerrit and Hall, Ian R.},
doi = {10.1038/ncomms15867},
issn = {2041-1723},
journal = {Nature Communications},
month = {aug},
number = {1},
pages = {15867},
pmid = {28681844},
title = {{Sea level fall during glaciation stabilized atmospheric CO2 by enhanced volcanic degassing}},
url = {http://www.nature.com/articles/ncomms15867},
volume = {8},
year = {2017}
}
@article{Hauck2010,
abstract = {The amount of anthropogenic CO2 (Cant) that entered the Weddell Sea between 1992 and 2008 (Cant1992–2008) was assessed using the extended multiple linear regression (eMLR) method. In the Warm Deep Water (WDW) and the Weddell Sea Bottom Water (WSBW), Cant1992–2008 values were insignificant, whereas values as high as 8 $\mu$mol kg−1 were observed over the shelf. Cant1992–2008 concentrations in the surface layer varied with latitude between 2 and 11 $\mu$mol kg−1. Weak intrusion of anthropogenic CO2 into Weddell Sea Deep Water (WSDW) was demonstrated (Cant1992–2008 yields 1.5–2 $\mu$mol kg−1). That more Cant1992–2008 was found in the WSDW than in the WSBW is surprising, but can be explained by intense ventilation of the WSDW originating from east of the Weddell Gyre. The invasion of Cant1992–2008 provokes a shift in the equilibria of the carbonate system, resulting in acidification and reduction of CO32− concentration. The mean decrease of pH in the upper 200 m layer was 0.016. The largest decrease of calcite and aragonite saturation states was observed at the surface. This implies that surface waters might become undersaturated with respect to aragonite in the future while the underlying WDW is still saturated. Results of this analysis suggest that complete undersaturation of surface waters in the Weddell Sea will be reached after the 21st century.},
author = {Hauck, J and Hoppema, M and Bellerby, R G J and V{\"{o}}lker, C and Wolf-Gladrow, D},
doi = {10.1029/2009JC005479},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Oceans},
keywords = {Weddell Sea,acidification,anthropogenic carbon},
month = {mar},
number = {C3},
pages = {C03004},
title = {{Data-based estimation of anthropogenic carbon and acidification in the Weddell Sea on a decadal timescale}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2009JC005479 http://doi.wiley.com/10.1029/2009JC005479},
volume = {115},
year = {2010}
}
@article{ISI:000363703800008,
abstract = {We use a suite of eight ocean biogeochemical/ecological general circulation models from the Marine Ecosystem Model Intercomparison Project and Coupled Model Intercomparison Project Phase 5 archives to explore the relative roles of changes in winds (positive trend of Southern Annular Mode, SAM) and in warming- and freshening-driven trends of upper ocean stratification in altering export production and CO2 uptake in the Southern Ocean at the end of the 21st century. The investigated models simulate a broad range of responses to climate change, with no agreement on a dominance of either the SAM or the warming signal south of 44 degrees S. In the southernmost zone, i.e., south of 58 degrees S, they concur on an increase of biological export production, while between 44 and 58 degrees S the models lack consensus on the sign of change in export. Yet in both regions, the models show an enhanced CO2 uptake during spring and summer. This is due to a larger CO2(aq) drawdown by the same amount of summer export production at a higher Revelle factor at the end of the 21st century. This strongly increases the importance of the biological carbon pump in the entire Southern Ocean. In the temperate zone, between 30 and 44 degrees S, all models show a predominance of the warming signal and a nutrient-driven reduction of export production. As a consequence, the share of the regions south of 44 degrees S to the total uptake of the Southern Ocean south of 30 degrees S is projected to increase at the end of the 21st century from 47 to 66{\%} with a commensurable decrease to the north. Despite this major reorganization of the meridional distribution of the major regions of uptake, the total uptake increases largely in line with the rising atmospheric CO2. Simulations with the MITgcm-REcoM2 model show that this is mostly driven by the strong increase of atmospheric CO2, with the climate-driven changes of natural CO2 exchange offsetting that trend only to a limited degree (approximate to 10{\%}) and with negligible impact of climate effects on anthropogenic CO2 uptake when integrated over a full annual cycle south of 30 degrees S.},
author = {Hauck, J and V{\"{o}}lker, C. and Wolf-Gladrow, D A and Laufk{\"{o}}tter, C and Vogt, M and Aumont, O and Bopp, L and Buitenhuis, E T and Doney, S C and Dunne, J and Gruber, N and Hashioka, T and John, J and Qu{\'{e}}r{\'{e}}, C. Le and Lima, I D and Nakano, H and S{\'{e}}f{\'{e}}rian, R. and Totterdell, I},
doi = {10.1002/2015GB005140},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {sep},
number = {9},
pages = {1451--1470},
title = {{On the Southern Ocean CO2 uptake and the role of the biological carbon pump in the 21st century}},
url = {http://doi.wiley.com/10.1002/2015GB005140},
volume = {29},
year = {2015}
}
@article{Hauck2015,
author = {Hauck, J. and V{\"{o}}lker, C.},
doi = {10.1002/2015GL063070},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {mar},
number = {5},
pages = {1459--1464},
title = {{Rising atmospheric CO2 leads to large impact of biology on Southern Ocean CO2 uptake via changes of the Revelle factor}},
url = {http://doi.wiley.com/10.1002/2015GL063070},
volume = {42},
year = {2015}
}
@article{Hauck2016a,
abstract = {arbon dioxide removal (CDR) approaches are efforts to reduce the atmospheric CO2 concentration. Here we use a marine carbon cycle model to investigate the effects of one CDR technique: the open ocean dissolution of the iron-containing mineral olivine. We analyse the maximum CDR potential of an annual dissolution of 3 Pg olivine during the 21st century and focus on the role of the micronutrient iron for the biological carbon pump. Distributing the products of olivine dissolution (bicarbonate, silicic acid, iron) uniformly in the global surface ocean has a maximum CDR potential of 0.57. gC/g-olivine mainly due to the alkalinisation of the ocean, with a significant contribution from the fertilisation of phytoplankton with silicic acid and iron. The part of the CDR caused by ocean fertilisation is not permanent, while the CO2 sequestered by alkalinisation would be stored in the ocean as long as alkalinity is not removed from the system. For high CO2 emission scenarios the CDR potential due to the alkalinity input becomes more efficient over time with increasing ocean acidification. The alkalinity-induced CDR potential scales linearly with the amount of olivine, while the iron-induced CDR saturates at 113 PgC per century (on average similar to 1.1 PgC. yr(-1)) for an iron input rate of 2.3. Tg. Fe. yr(-1) (1{\%} of the iron contained in 3 Pg olivine). The additional iron-related CO2 uptake occurs in the Southern Ocean and in the iron-limited regions of the Pacific. Effects of this approach on surface ocean pH are small ({\textless}0.01).},
author = {Hauck, Judith and K{\"{o}}hler, Peter and Wolf-Gladrow, Dieter and V{\"{o}}lker, Christoph},
doi = {10.1088/1748-9326/11/2/024007},
issn = {1748-9326},
journal = {Environmental Research Letters},
keywords = {article is available online,biological carbon pump,carbon dioxide removal,enhanced weathering,geoengineering,iron fertilisation,ocean alkalinisation,supplementary material for this},
month = {feb},
number = {2},
pages = {024007},
publisher = {IOP Publishing},
title = {{Iron fertilisation and century-scale effects of open ocean dissolution of olivine in a simulated CO2 removal experiment}},
url = {http://stacks.iop.org/1748-9326/11/i=2/a=024007?key=crossref.7d5ab8a17f2b2687fa59e1d3b4b66cf6 http://dx.doi.org/10.1088/1748-9326/11/2/024007 http://iopscience.iop.org/article/10.1088/1748-9326/11/2/024007},
volume = {11},
year = {2016}
}
@article{Hauck2020,
abstract = {Based on the 2019 assessment of the Global Carbon Project, the ocean took up on average, 2.5 ± 0.6 PgC yr −1 or 23 ± 5{\%} of the total anthropogenic CO 2 emissions over the decade 2009-2018. This sink estimate is based on simulation results from global ocean biogeochemical models (GOBMs) and is compared to data-products based on observations of surface ocean pCO 2 (partial pressure of CO 2) accounting for the outgassing of river-derived CO 2. Here we evaluate the GOBM simulations by comparing the simulated surface ocean pCO 2 to observations. Based on this comparison, the simulations are well-suited for quantifying the global ocean carbon sink on the timescale of the annual mean and its multi-decadal trend (RMSE {\textless}20 µatm), as well as on the timescale of multi-year variability (RMSE {\textless}10 µatm), despite the large model-data mismatch on the seasonal timescale (RMSE of 20-80 µatm). Biases in GOBMs have a small effect on the global mean ocean sink (0.05 PgC yr −1), but need to be addressed to improve the regional budgets and model-data comparison. Accounting for non-mapped areas in the data-products reduces their spread as measured by the standard deviation by a third. There is growing evidence and consistency among methods with regard to the patterns of the multi-year variability of the ocean carbon sink, with a global stagnation in the 1990s and an extra-tropical strengthening in the 2000s. GOBMs and data-products point consistently to a shift from a tropical CO 2 source to a CO 2 sink in recent years. On average, the GOBMs reveal less variations in the sink than the data-based products. Despite the reasonable simulation of surface ocean pCO 2 by the GOBMs, there are discrepancies between the resulting sink estimate from GOBMs and data-products. These discrepancies are within the uncertainty of the river flux adjustment, increase over time, and largely stem from the Southern Ocean. Progress in our understanding Hauck et al. Global Carbon Budget Ocean Sink of the global ocean carbon sink necessitates significant advancement in modeling and observing the Southern Ocean carbon sink including (i) a game-changing increase in high-quality pCO 2 observations, and (ii) a critical re-evaluation of the regional river flux adjustment.},
author = {Hauck, Judith and Zeising, Moritz and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Gruber, Nicolas and Bakker, Dorothee C. E. and Bopp, Laurent and Chau, Thi Tuyet Trang and G{\"{u}}rses, {\"{O}}zg{\"{u}}r and Ilyina, Tatiana and Landsch{\"{u}}tzer, Peter and Lenton, Andrew and Resplandy, Laure and R{\"{o}}denbeck, Christian and Schwinger, J{\"{o}}rg and S{\'{e}}f{\'{e}}rian, Roland},
doi = {10.3389/fmars.2020.571720},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
keywords = {anthropogenic CO2,ocean carbon cycle model evaluation,ocean carbon uptake,riverine carbon flux,seasonal cycle,variability of the ocean carbon sink},
month = {oct},
pages = {852},
publisher = {Frontiers Media SA},
title = {{Consistency and Challenges in the Ocean Carbon Sink Estimate for the Global Carbon Budget}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2020.571720 https://www.frontiersin.org/articles/10.3389/fmars.2020.571720/full www.frontiersin.org},
volume = {7},
year = {2020}
}
@article{Hauri2016,
author = {Hauri, Claudine and Friedrich, Tobias and Timmermann, Axel},
doi = {10.1038/nclimate2844},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {feb},
number = {2},
pages = {172--176},
publisher = {Nature Publishing Group},
title = {{Abrupt onset and prolongation of aragonite undersaturation events in the Southern Ocean}},
url = {https://doi.org/10.1038/nclimate2844 10.1038/nclimate2844 https://www.nature.com/articles/nclimate2844{\#}supplementary-information http://www.nature.com/articles/nclimate2844},
volume = {6},
year = {2016}
}
@article{Hauri2015,
abstract = {Abstract. We present 20 years of seawater inorganic carbon measurements collected along the western shelf and slope of the Antarctic Peninsula. Water column observations from summertime cruises and seasonal surface underway pCO2 measurements provide unique insights into the spatial, seasonal, and interannual variability in this dynamic system. Discrete measurements from depths {\textgreater} 2000 m align well with World Ocean Circulation Experiment observations across the time series and underline the consistency of the data set. Surface total alkalinity and dissolved inorganic carbon data showed large spatial gradients, with a concomitant wide range of {\&}Omega;arag (arag despite glacial and sea-ice meltwater input. In support of previous studies, we observed Redfield behavior of regional C / N nutrient utilization, while the C / P (80.5 ± 2.5) and N / P (11.7 ± 0.3) molar ratios were significantly lower than the Redfield elemental stoichiometric values. Seasonal salinity-based predictions of {\&}Omega;arag suggest that surface waters remained mostly supersaturated with regard to aragonite throughout the study. However, more than 20 {\%} of the predictions for winters and springs between 1999 and 2013 resulted in {\&}Omega;arag arag may have implications for important organisms such as pteropods. Even though we did not detect any statistically significant long-term trends, the combination of on$\backslash$$\backslash$-going ocean acidification and freshwater input may soon induce more unfavorable conditions than the ecosystem experiences today.},
author = {Hauri, C and Doney, S C and Takahashi, T and Erickson, M and Jiang, G and Ducklow, H W},
doi = {10.5194/bg-12-6761-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {nov},
number = {22},
pages = {6761--6779},
publisher = {Copernicus Publications},
title = {{Two decades of inorganic carbon dynamics along the West Antarctic Peninsula}},
url = {http://www.biogeosciences.net/12/6761/2015/ http://www.biogeosciences.net/12/6761/2015/bg-12-6761-2015.pdf https://www.biogeosciences.net/12/6761/2015/},
volume = {12},
year = {2015}
}
@article{Hauri2013,
abstract = {Abstract. Due to seasonal upwelling, the upper ocean waters of the California Current System (CCS) have a naturally low pH and aragonite saturation state ({\&}Omega;arag), making this region particularly prone to the effects of ocean acidification. Here, we use the Regional Oceanic Modeling System (ROMS) to conduct preindustrial and transient (1995–2050) simulations of ocean biogeochemistry in the CCS. The transient simulations were forced with increasing atmospheric pCO2 and increasing oceanic dissolved inorganic carbon concentrations at the lateral boundaries, as projected by the NCAR CSM 1.4 model for the IPCC SRES A2 scenario. Our results show a large seasonal variability in pH (range of {\~{}} 0.14) and {\&}Omega;arag ({\~{}} 0.2) for the nearshore areas (50 km from shore). This variability is created by the interplay of physical and biogeochemical processes. Despite this large variability, we find that present-day pH and {\&}Omega;arag have already moved outside of their simulated preindustrial variability envelopes (defined by ±1 temporal standard deviation) due to the rapidly increasing concentrations of atmospheric CO2. The nearshore surface pH of the northern and central CCS are simulated to move outside of their present-day variability envelopes by the mid-2040s and late 2030s, respectively. This transition may occur even earlier for nearshore surface {\&}Omega;arag, which is projected to depart from its present-day variability envelope by the early- to mid-2030s. The aragonite saturation horizon of the central CCS is projected to shoal into the upper 75 m within the next 25 yr, causing near-permanent undersaturation in subsurface waters. Due to the model's overestimation of {\&}Omega;arag, this transition may occur even earlier than simulated by the model. Overall, our study shows that the CCS joins the Arctic and Southern oceans as one of only a few known ocean regions presently approaching the dual threshold of widespread and near-permanent undersaturation with respect to aragonite and a departure from its variability envelope. In these regions, organisms may be forced to rapidly adjust to conditions that are both inherently chemically challenging and also substantially different from past conditions.},
author = {Hauri, C. and Gruber, N. and Vogt, M. and Doney, S. C. and Feely, R. A. and Lachkar, Z. and Leinweber, A. and McDonnell, A. M. P. and Munnich, M. and Plattner, G.-K.},
doi = {10.5194/bg-10-193-2013},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jan},
number = {1},
pages = {193--216},
title = {{Spatiotemporal variability and long-term trends of ocean acidification in the California Current System}},
url = {http://www.biogeosciences.net/10/193/2013/ https://www.biogeosciences.net/10/193/2013/},
volume = {10},
year = {2013}
}
@article{Hauri2020,
abstract = {Abstract. The coastal ecosystem of the Gulf of Alaska (GOA) is especially vulnerable to the effects of ocean acidification and climate change. Detection of these long-term trends requires a good understanding of the system's natural state. The GOA is a highly dynamic system that exhibits large inorganic carbon variability on subseasonal to interannual timescales. This variability is poorly understood due to the lack of observations in this expansive and remote region. We developed a new model setup for the GOA that couples the three-dimensional Regional Oceanic Model System (ROMS) and the Carbon, Ocean Biogeochemistry and Lower Trophic (COBALT) ecosystem model. To improve our conceptual understanding of the system, we conducted a hindcast simulation from 1980 to 2013. The model was explicitly forced with temporally and spatially varying coastal freshwater discharges from a high-resolution terrestrial hydrological model, thereby affecting salinity, alkalinity, dissolved inorganic carbon, and nutrient concentrations. This represents a substantial improvement over previous GOA modeling attempts. Here, we evaluate the model on seasonal to interannual timescales using the best available inorganic carbon observations. The model was particularly successful in reproducing observed aragonite oversaturation and undersaturation of near-bottom water in May and September, respectively. The largest deficiency in the model is its inability to adequately simulate springtime surface inorganic carbon chemistry, as it overestimates surface dissolved inorganic carbon, which translates into an underestimation of the surface aragonite saturation state at this time. We also use the model to describe the seasonal cycle and drivers of inorganic carbon parameters along the Seward Line transect in under-sampled months. Model output suggests that the majority of the near-bottom water along the Seward Line is seasonally undersaturated with respect to aragonite between June and January, as a result of upwelling and remineralization. Such an extensive period of reoccurring aragonite undersaturation may be harmful to ocean acidification-sensitive organisms. Furthermore, the influence of freshwater not only decreases the aragonite saturation state in coastal surface waters in summer and fall, but it simultaneously decreases the surface partial pressure of carbon dioxide (pCO2), thereby decoupling the aragonite saturation state from pCO2. The full seasonal cycle and geographic extent of{\ldots}},
author = {Hauri, Claudine and Schultz, Cristina and Hedstrom, Katherine and Danielson, Seth and Irving, Brita and Doney, Scott C and Dussin, Raphael and Curchitser, Enrique N and Hill, David F and Stock, Charles A},
doi = {10.5194/bg-17-3837-2020},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jul},
number = {14},
pages = {3837--3857},
title = {{A regional hindcast model simulating ecosystem dynamics, inorganic carbon chemistry, and ocean acidification in the Gulf of Alaska}},
volume = {17},
year = {2020}
}
@article{Haustein2017,
abstract = {We propose a simple real-time index of global human-induced warming and assess its robustness to uncertainties in climate forcing and short-term climate fluctuations. This index provides improved scientific context for temperature stabilisation targets and has the potential to decrease the volatility of climate policy. We quantify uncertainties arising from temperature observations, climate radiative forcings, internal variability and the model response. Our index and the associated rate of human-induced warming is compatible with a range of other more sophisticated methods to estimate the human contribution to observed global temperature change.},
author = {Haustein, K and Allen, M R and Forster, P M and Otto, F E L and Mitchell, D M and Matthews, H D and Frame, D J},
doi = {10.1038/s41598-017-14828-5},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {15417},
title = {{A real-time Global Warming Index}},
url = {https://doi.org/10.1038/s41598-017-14828-5 http://www.nature.com/articles/s41598-017-14828-5},
volume = {7},
year = {2017}
}
@article{Haynes2020a,
abstract = {The Paleocene–Eocene Thermal Maximum (PETM) (55.6 Mya) was a geologically rapid carbon-release event that is considered the closest natural analog to anthropogenic CO 2 emissions. Recent work has used boron-based proxies in planktic foraminifera to characterize the extent of surface-ocean acidification that occurred during the event. However, seawater acidity alone provides an incomplete constraint on the nature and source of carbon release. Here, we apply previously undescribed culture calibrations for the B/Ca proxy in planktic foraminifera and use them to calculate relative changes in seawater-dissolved inorganic carbon (DIC) concentration, surmising that Pacific surface-ocean DIC increased by + 1 , 010 − 646 + 1,415 µmol/kg during the peak-PETM. Making reasonable assumptions for the pre-PETM oceanic DIC inventory, we provide a fully data-driven estimate of the PETM carbon source. Our reconstruction yields a mean source carbon $\delta$ 13 C of −10‰ and a mean increase in the oceanic C inventory of +14,900 petagrams of carbon (PgC), pointing to volcanic CO 2 emissions as the main carbon source responsible for PETM warming.},
author = {Haynes, Laura L. and H{\"{o}}nisch, B{\"{a}}rbel},
doi = {10.1073/pnas.2003197117},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {sep},
number = {39},
pages = {24088--24095},
title = {{The seawater carbon inventory at the Paleocene–Eocene Thermal Maximum}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.2003197117},
volume = {117},
year = {2020}
}
@article{He2016,
abstract = {Soil is the largest terrestrial carbon reservoir and may influence the sign and magnitude of carbon cycle–climate feedbacks. Many Earth system models (ESMs) estimate a significant soil carbon sink by 2100, yet the underlying carbon dynamics determining this response have not been systematically tested against observations. We used 14C data from 157 globally distributed soil profiles sampled to 1-meter depth to show that ESMs underestimated the mean age of soil carbon by a factor of more than six (430 ± 50 years versus 3100 ± 1800 years). Consequently, ESMs overestimated the carbon sequestration potential of soils by a factor of nearly two (40 ± 27{\%}). These inconsistencies suggest that ESMs must better represent carbon stabilization processes and the turnover time of slow and passive reservoirs when simulating future atmospheric carbon dioxide dynamics.},
author = {He, Yujie and Trumbore, Susan E and Torn, Margaret S and Harden, Jennifer W and Vaughn, Lydia J S and Allison, Steven D and Randerson, James T},
doi = {10.1126/science.aad4273},
journal = {Science},
month = {sep},
number = {6306},
pages = {1419--1424},
title = {{Radiocarbon constraints imply reduced carbon uptake by soils during the 21st century}},
url = {http://science.sciencemag.org/content/353/6306/1419.abstract},
volume = {353},
year = {2016}
}
@article{He2020,
author = {He, Jian and Naik, Vaishali and Horowitz, Larry W. and Dlugokencky, Ed and Thoning, Kirk},
doi = {10.5194/acp-20-805-2020},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {jan},
number = {2},
pages = {805--827},
title = {{Investigation of the global methane budget over 1980–2017 using GFDL-AM4.1}},
url = {https://acp.copernicus.org/articles/20/805/2020/},
volume = {20},
year = {2020}
}
@article{Heck2018,
abstract = {Under the Paris Agreement, 195 nations have committed to holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and to strive to limit the increase to 1.5 °C (ref. 1). It is noted that this requires "a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of the century"1. This either calls for zero greenhouse gas (GHG) emissions or a balance between positive and negative emissions (NE)2,3. Roadmaps and socio-economic scenarios compatible with a 2 °C or 1.5 °C goal depend upon NE via bioenergy with carbon capture and storage (BECCS) to balance remaining GHG emissions4–7. However, large-scale deployment of BECCS would imply significant impacts on many Earth system components besides atmospheric CO2 concentrations8,9. Here we explore the feasibility of NE via BECCS from dedicated plantations and potential trade-offs with planetary boundaries (PBs)10,11 for multiple socio-economic pathways. We show that while large-scale BECCS is intended to lower the pressure on the PB for climate change, it would most likely steer the Earth system closer to the PB for freshwater use and lead to further transgression of the PBs for land-system change, biosphere integrity and biogeochemical flows.},
author = {Heck, Vera and Gerten, Dieter and Lucht, Wolfgang and Popp, Alexander},
doi = {10.1038/s41558-017-0064-y},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {feb},
number = {2},
pages = {151--155},
title = {{Biomass-based negative emissions difficult to reconcile with planetary boundaries}},
url = {https://doi.org/10.1038/s41558-017-0064-y http://www.nature.com/articles/s41558-017-0064-y},
volume = {8},
year = {2018}
}
@article{Heck2016,
abstract = {Biological carbon sequestration through implementation of biomass plantations is currently being discussed as an option for climate engineering (CE) should mitigation efforts fail to substantially reduce greenhouse gas emissions. As it is a plant-based CE option that extracts CO2 from the atmosphere, it might be considered a ‘green' CE method that moves the biosphere closer to its natural, i.e. pre-Neolithic, state. Here, we test this hypothesis by comparing the biogeochemical (water- and carbon-related) changes induced by biomass plantations compared to those induced by historical human land cover and land use change. Results indicate that large-scale biomass plantations would produce a biogeochemical shift in the terrestrial biosphere which is, in absolute terms, even larger than that already produced by historical land use change. However, the nature of change would differ between a world dominated by biomass plantations and the current world inheriting the effects of historical land use, highlighting that large-scale tCDR would represent an additional distinct and massive human intervention into the biosphere. Contrasting the limited possibilities of tCDR to reduce the pressure on the planetary boundary for climate change with the potential negative implications on the status of other planetary boundaries highlights that tCDR via biomass plantations should not be considered a ‘green' CE method but a full scale engineering intervention.},
author = {Heck, Vera and Gerten, Dieter and Lucht, Wolfgang and Boysen, Lena R.},
doi = {10.1016/j.gloplacha.2015.12.008},
issn = {09218181},
journal = {Global and Planetary Change},
month = {feb},
pages = {123--130},
title = {{Is extensive terrestrial carbon dioxide removal a ‘green' form of geoengineering? A global modelling study}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0921818115301612},
volume = {137},
year = {2016}
}
@article{Helm2011,
abstract = {Comparing the high-quality oxygen climatology from the World Ocean Circulation Experiment to earlier data we reveal near-global decreases in oxygen levels in the upper ocean between the 1970s and the 1990s. This globally averaged oxygen decrease is ?0.93 ± 0.23?mol l?1, which is equivalent to annual oxygen losses of ?0.55 ± 0.13 ? 1014 mol yr?1(100?1000 m). The strongest decreases in oxygen occur in the mid-latitudes of both hemispheres, near regions where there is strong water renewal and exchange between the ocean interior and surface waters. Approximately 15{\%} of global oxygen decrease can be explained by a warmer mixed-layer reducing the capacity of water to store oxygen, while the remainder is consistent with an overall decrease in the exchange between surface waters and the ocean interior. Here we suggest that this reduction in water mass renewal rates on a global scale is a consequence of increased stratification caused by warmer surface waters. These observations support climate model simulations of oxygen change under global warming scenarios.},
annote = {doi: 10.1029/2011GL049513},
author = {Helm, Kieran P and Bindoff, Nathaniel L and Church, John A},
doi = {10.1029/2011GL049513},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {density surfaces,isopycnal,overturning circulation,oxygen,oxygen concentration,thermohaline circulation},
month = {dec},
number = {23},
pages = {L23602},
publisher = {Wiley-Blackwell},
title = {{Observed decreases in oxygen content of the global ocean}},
url = {https://doi.org/10.1029/2011GL049513 http://doi.wiley.com/10.1029/2011GL049513},
volume = {38},
year = {2011}
}
@article{HEMES2019202,
abstract = {Restoring degraded peat soils presents an attractive, but largely untested, climate change mitigation approach. Drained peat soils used for agriculture can be large greenhouse gas sources. By restoring subsided peat soils to managed, impounded wetlands, significant agricultural emissions are avoided, and soil carbon can be sequestered and protected. Here, we synthesize 36 site-years of continuous carbon dioxide and methane flux data from a mesonetwork of eddy covariance towers in the Sacramento-San Joaquin Delta in California, USA to compute carbon and greenhouse gas budgets for drained agricultural land uses and compare these to restored deltaic wetlands. We found that restored wetlands effectively sequestered carbon and halted soil carbon loss associated with drained agricultural land uses. Depending on the age and disturbance regime of the restored wetland, many land use conversions from agriculture to restored wetland resulted in emission reductions over a 100-year timescale. With a simple model of radiative forcing and atmospheric lifetimes, we showed that restored wetlands do not begin to accrue greenhouse gas benefits until nearly a half century, and become net sinks from the atmosphere after a century. Due to substantial interannual variability and uncertainty about the multi-decadal successional trajectory of managed, restored wetlands, ongoing ecosystem flux measurements are critical for understanding the long-term impacts of wetland restoration for climate change mitigation.},
author = {Hemes, Kyle S and Chamberlain, Samuel D and Eichelmann, Elke and Anthony, Tyler and Valach, Amy and Kasak, Kuno and Szutu, Daphne and Verfaillie, Joe and Silver, Whendee L and Baldocchi, Dennis D},
doi = {10.1016/j.agrformet.2019.01.017},
issn = {0168-1923},
journal = {Agricultural and Forest Meteorology},
keywords = {Carbon dioxide,Greenhouse gas,Methane,Peat soil,Sequestration,Wetland restoration},
pages = {202--214},
title = {{Assessing the carbon and climate benefit of restoring degraded agricultural peat soils to managed wetlands}},
url = {http://www.sciencedirect.com/science/article/pii/S0168192319300176},
volume = {268},
year = {2019}
}
@article{Henderson2015,
abstract = {This study provides estimates of the net GHG mitigation potential of a selected range of management practices in the world's native and cultivated grazing lands. The Century and Daycent models are used to calculate the changes in soil carbon stocks, soil N2O emissions, and forage removals by ruminants associated with these practices. GLEAM is used in combination with these models to establish grazing area boundaries and to parameterize links between forage consumption, animal production and animal GHG emissions. This study provides an alternative to the usual approach of extrapolating from a small number of field studies and by modeling the linkage between soil, forage and animals it sheds new light on the net mitigation potential of C sequestration practices in the world's grazing lands. Three different mitigation practices are assessed in this study, namely, improved grazing management, legume sowing and N fertilization. We estimate that optimization of grazing pressure could sequester 148Tg CO2yr−1. The soil C sequestration potential of 203Tg CO2yr−1 for legume sowing was higher than for improved grazing management, despite being applied over a much smaller total area. However, N2O emissions from legumes were estimated to offset 28{\%} of its global C sequestration benefits, in CO2 equivalent terms. Conversely, N2O emissions from N fertilization exceeded soil C sequestration, in all regions. Our estimated potential for increasing C stocks though in grazing lands is lower than earlier worldwide estimates (Smith et al., 2007, Lal, 2004), mainly due to the much smaller grazing land area over which we estimate mitigation practices to be effective. A big concern is the high risk of the practices, particularly legumes, increasing soil-based GHGs if applied outside of this relatively small effective area. More work is needed to develop indicators, based on biophysical and management characteristics of grazing lands, to identify amenable areas before these practices can be considered ready for large scale implementation. The additional ruminant GHG emissions associated with higher forage output are likely to substantially reduce the mitigation potential of these practices, but could contribute to more GHG-efficient livestock production.},
author = {Henderson, Benjamin B. and Gerber, Pierre J. and Hilinski, Tom E. and Falcucci, Alessandra and Ojima, Dennis S. and Salvatore, Mirella and Conant, Richard T.},
doi = {10.1016/j.agee.2015.03.029},
issn = {01678809},
journal = {Agriculture, Ecosystems {\&} Environment},
month = {sep},
pages = {91--100},
title = {{Greenhouse gas mitigation potential of the world's grazing lands: Modeling soil carbon and nitrogen fluxes of mitigation practices}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880915001139},
volume = {207},
year = {2015}
}
@article{Henehan2013111,
abstract = {The boron isotope-pH proxy, applied to mixed-layer planktic foraminifera, has great potential for estimating past CO2 levels, which in turn is crucial to advance our understanding of how this greenhouse gas influences Earth's climate. Previous culture experiments have shown that, although the boron isotopic compositions of various planktic foraminifera are pH dependent, they do not agree with the aqueous geochemical basis of the proxy. Here we outline the results of culture experiments on Globigerinoides ruber (white) across a range of pH (∼7.5–8.2) and analysed via multicollector inductively-coupled plasma mass spectrometry (MC-ICPMS), and compare these data to core-top and sediment-trap samples to derive a robust new species-specific boron isotope-pH calibration. Consistent with earlier culture studies, we show a reduced pH dependency of the boron isotopic composition of symbiont-bearing planktonic foraminifera compared to borate ion in seawater. We also present evidence for a size fraction effect in the $\delta$11B of G. ruber. Finally, we reconstruct atmospheric CO2 concentrations over the last deglacial using our new calibration at two equatorial sites, ODP Site 999A and Site GeoB1523-1. These data provide further grounding for the application of the boron isotope-pH proxy in reconstructions of past atmospheric CO2 levels.},
author = {Henehan, Michael J and Rae, James W.B. and Foster, Gavin L and Erez, Jonathan and Prentice, Katherine C and Kucera, Michal and Bostock, Helen C and Mart{\'{i}}nez-Bot{\'{i}}, Miguel A and Milton, J Andy and Wilson, Paul A and Marshall, Brittney J and Elliott, Tim},
doi = {10.1016/j.epsl.2012.12.029},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {Globigerinoides ruber,MC-ICPMS,boron isotopes,culture calibration,pCO2 reconstruction,planktic foraminifera},
month = {feb},
number = {0},
pages = {111--122},
title = {{Calibration of the boron isotope proxy in the planktonic foraminifera Globigerinoides ruber for use in palaeo-CO2 reconstruction}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X12007157 http://linkinghub.elsevier.com/retrieve/pii/S0012821X12007157 https://linkinghub.elsevier.com/retrieve/pii/S0012821X12007157},
volume = {364},
year = {2013}
}
@article{Henley2020,
abstract = {The Southern Ocean plays a critical role in regulating global climate as a major sink for atmospheric carbon dioxide (CO2), and in global ocean biogeochemistry by supplying nutrients to the global thermocline, thereby influencing global primary production and carbon export. Biogeochemical processes within the Southern Ocean regulate regional primary production and biological carbon uptake, primarily through iron supply, and support ecosystem functioning over a range of spatial and temporal scales. Here, we assimilate existing knowledge and present new data to examine the biogeochemical cycles of iron, carbon and major nutrients, their key drivers and their responses to, and roles in, contemporary climate and environmental change. Projected increases in iron supply, coupled with increases in light availability to phytoplankton through increased near-surface stratification and longer ice-free periods, are very likely to increase primary production and carbon export around Antarctica. Biological carbon uptake is likely to increase for the Southern Ocean as a whole, whilst there is greater uncertainty around projections of primary production in the Sub-Antarctic and basin-wide changes in phytoplankton species composition, as well as their biogeochemical consequences. Phytoplankton, zooplankton, higher trophic level organisms and microbial communities are strongly influenced by Southern Ocean biogeochemistry, in particular through nutrient supply and ocean acidification. In turn, these organisms exert important controls on biogeochemistry through carbon storage and export, nutrient recycling and redistribution, and benthic-pelagic coupling. The key processes described in this paper are summarised in the Graphical Abstract. Climate-mediated changes in Southern Ocean biogeochemistry over the coming decades are very likely to impact primary production, sea-air CO2 exchange and ecosystem functioning within and beyond this vast and critically important ocean region.},
author = {Henley, Sian F and Cavan, Emma L and Fawcett, Sarah E and Kerr, Rodrigo and Monteiro, Thiago and Sherrell, Robert M and Bowie, Andrew R and Boyd, Philip W and Barnes, David K A and Schloss, Irene R and Marshall, Tanya and Flynn, Raquel and Smith, Shantelle},
doi = {10.3389/fmars.2020.00581},
isbn = {2296-7745},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {jul},
pages = {581},
title = {{Changing Biogeochemistry of the Southern Ocean and Its Ecosystem Implications}},
volume = {7},
year = {2020}
}
@article{ISI:000371515300020,
abstract = {Understanding the influence of anthropogenic forcing on the marine biosphere is a high priority. Climate change-driven trends need to be accurately assessed and detected in a timely manner. As part of the effort towards detection of long-term trends, a network of ocean observatories and time series stations provide high quality data for a number of key parameters, such as pH, oxygen concentration or primary production (PP). Here, we use an ensemble of global coupled climate models to assess the temporal and spatial scales over which observations of eight biogeochemically relevant variables must be made to robustly detect a long-term trend. We find that, as a global average, continuous time series are required for between 14 (pH) and 32 (PP) years to distinguish a climate change trend from natural variability. Regional differences are extensive, with low latitudes and the Arctic generally needing shorter time series ({\textless}similar to 30years) to detect trends than other areas. In addition, we quantify the footprint' of existing and planned time series stations, that is the area over which a station is representative of a broader region. Footprints are generally largest for pH and sea surface temperature, but nevertheless the existing network of observatories only represents 9-15{\%} of the global ocean surface. Our results present a quantitative framework for assessing the adequacy of current and future ocean observing networks for detection and monitoring of climate change-driven responses in the marine ecosystem.},
author = {Henson, Stephanie A and Beaulieu, Claudie and Lampitt, Richard},
doi = {10.1111/gcb.13152},
issn = {13541013},
journal = {Global Change Biology},
month = {apr},
number = {4},
pages = {1561--1571},
title = {{Observing climate change trends in ocean biogeochemistry: when and where}},
url = {http://doi.wiley.com/10.1111/gcb.13152},
volume = {22},
year = {2016}
}
@article{Herndl2013,
author = {Herndl, Gerhard J. and Reinthaler, Thomas},
doi = {10.1038/ngeo1921},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {sep},
number = {9},
pages = {718--724},
title = {{Microbial control of the dark end of the biological pump}},
url = {http://www.nature.com/articles/ngeo1921},
volume = {6},
year = {2013}
}
@article{herrington14,
abstract = {Abstract. Recent studies have identified an approximately proportional relationship between global warming and cumulative carbon emissions, yet the robustness of this relationship has not been tested over a broad range of cumulative emissions and emission rates. This study explores the path dependence of the climate and carbon cycle response using an Earth system model of intermediate complexity forced with 24 idealized emissions scenarios across five cumulative emission groups (1275–5275 Gt C) with varying rates of emission. We find the century-scale climate and carbon cycle response after cessation of emissions to be approximately independent of emission pathway for all cumulative emission levels considered. The ratio of global mean temperature change to cumulative emissions – referred to as the transient climate response to cumulative carbon emissions (TCRE) – is found to be constant for cumulative emissions lower than {\&}sim;1500 Gt C but to decline with higher cumulative emissions. The TCRE is also found to decrease with increasing emission rate. The response of Arctic sea ice is found to be approximately proportional to cumulative emissions, while the response of the Atlantic Meridional Overturning Circulation does not scale linearly with cumulative emissions, as its peak response is strongly dependent on emission rate. Ocean carbon uptake weakens with increasing cumulative emissions, while land carbon uptake displays non-monotonic behavior, increasing up to a cumulative emission threshold of {\&}sim;2000 Gt C and then declining.},
author = {Herrington, T and Zickfeld, K},
doi = {10.5194/esd-5-409-2014},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {nov},
number = {2},
pages = {409--422},
title = {{Path independence of climate and carbon cycle response over a broad range of cumulative carbon emissions}},
url = {https://www.earth-syst-dynam.net/5/409/2014/},
volume = {5},
year = {2014}
}
@article{Hewitt2016a,
abstract = {There is mounting evidence that resolving mesoscale eddies and western boundary currents as well as topographically controlled flows can play an important role in air-sea interaction associated with vertical and lateral transports of heat and salt. Here we describe the development of the Met Office Global Coupled Model version 2 (GC2) with increased resolution relative to the standard model: the ocean resolution is increased from 1/4 to 1/12° (28 to 9 km at the Equator), the atmosphere resolution increased from 60 km (N216) to 25 km (N512) and the coupling period reduced from 3 hourly to hourly. The technical developments that were required to build a version of the model at higher resolution are described as well as results from a 20-year simulation. The results demonstrate the key role played by the enhanced resolution of the ocean model: reduced sea surface temperature (SST) biases, improved ocean heat transports, deeper and stronger overturning circulation and a stronger Antarctic Circumpolar Current. Our results suggest that the improvements seen here require high resolution in both atmosphere and ocean components as well as high-frequency coupling. These results add to the body of evidence suggesting that ocean resolution is an important consideration when developing coupled models for weather and climate applications.},
author = {Hewitt, Helene T. and Roberts, Malcolm J. and Hyder, Pat and Graham, Tim and Rae, Jamie and Belcher, Stephen E. and Bourdall{\'{e}}-Badie, Romain and Copsey, Dan and Coward, Andrew and Guiavarch, Catherine and Harris, Chris and Hill, Richard and Hirschi, Jo{\"{e}}l J.M. and Madec, Gurvan and Mizielinski, Matthew S. and Neininger, Erica and New, Adrian L. and Rioual, Jean Christophe and Sinha, Bablu and Storkey, David and Shelly, Ann and Thorpe, Livia and Wood, Richard A.},
doi = {10.5194/gmd-9-3655-2016},
issn = {19919603},
journal = {Geoscientific Model Development},
month = {oct},
number = {10},
pages = {3655--3670},
publisher = {Copernicus GmbH},
title = {{The impact of resolving the Rossby radius at mid-latitudes in the ocean: Results from a high-resolution version of the Met Office GC2 coupled model}},
volume = {9},
year = {2016}
}
@article{HicksPries2013,
abstract = {Abstract Ecosystem respiration (Reco) is one of the largest terrestrial carbon (C) fluxes. The effect of climate change on Reco depends on the responses of its autotrophic and heterotrophic components. How autotrophic and heterotrophic respiration sources respond to climate change is especially important in ecosystems underlain by permafrost. Permafrost ecosystems contain vast stores of soil C (1672 Pg) and are located in northern latitudes where climate change is accelerated. Warming will cause a positive feedback to climate change if heterotrophic respiration increases without corresponding increases in primary production. We quantified the response of autotrophic and heterotrophic respiration to permafrost thaw across the 2008 and 2009 growing seasons. We partitioned Reco using ?14C and $\delta$13C into four sources?two autotrophic (above ? and belowground plant structures) and two heterotrophic (young and old soil). We sampled the ?14C and $\delta$13C of sources using incubations and the ?14C and $\delta$13C of Reco using field measurements. We then used a Bayesian mixing model to solve for the most likely contributions of each source to Reco. Autotrophic respiration ranged from 40 to 70{\%} of Reco and was greatest at the height of the growing season. Old soil heterotrophic respiration ranged from 6 to 18{\%} of Reco and was greatest where permafrost thaw was deepest. Overall, growing season fluxes of autotrophic and old soil heterotrophic respiration increased as permafrost thaw deepened. Areas with greater thaw also had the greatest primary production. Warming in permafrost ecosystems therefore leads to increased plant and old soil respiration that is initially compensated by increased net primary productivity. However, barring large shifts in plant community composition, future increases in old soil respiration will likely outpace productivity, resulting in a positive feedback to climate change.},
annote = {https://doi.org/10.1111/gcb.12058},
author = {{Hicks Pries}, Caitlin E and Schuur, Edward A G and Crummer, Kathryn G},
doi = {10.1111/gcb.12058},
issn = {1354-1013},
journal = {Global Change Biology},
keywords = {autotrophic respiration,ecosystem respiration,heterotrophic respiration,partitioning,permafrost thaw,radiocarbon,seasonality,$\delta$13C},
month = {feb},
number = {2},
pages = {649--661},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Thawing permafrost increases old soil and autotrophic respiration in tundra: Partitioning ecosystem respiration using $\delta$13C and ∆14C}},
url = {https://doi.org/10.1111/gcb.12058},
volume = {19},
year = {2013}
}
@article{HicksPries2017,
abstract = {Soils contain about twice as much carbon as Earth{\&}{\#}039;s atmosphere, so their response to warming is crucial to understanding carbon fluxes in a changing climate. Past studies have heated soil to a depth of 5 to 20 cm to examine such fluxes. Hicks Pries et al. heated the ground to a depth of 100 cm. Extending measurements to that depth revealed that 4°C of warming increased annual soil respiration by 34 to 37{\%}—a considerable amount more than previously observed.Science, this issue p. 1420Soil organic carbon harbors three times as much carbon as Earth's atmosphere, and its decomposition is a potentially large climate change feedback and major source of uncertainty in climate projections. The response of whole-soil profiles to warming has not been tested in situ. In a deep warming experiment in mineral soil, we found that CO2 production from all soil depths increased with 4°C warming; annual soil respiration increased by 34 to 37{\%}. All depths responded to warming with similar temperature sensitivities, driven by decomposition of decadal-aged carbon. Whole-soil warming reveals a larger soil respiration response than many in situ experiments (most of which only warm the surface soil) and models.},
author = {{Hicks Pries}, Caitlin E and Castanha, C and Porras, R C and Torn, M S},
doi = {10.1126/science.aal1319},
journal = {Science},
month = {mar},
number = {6332},
pages = {1420--1423},
title = {{The whole-soil carbon flux in response to warming}},
url = {http://science.sciencemag.org/content/355/6332/1420.abstract},
volume = {355},
year = {2017}
}
@article{Higgins2012,
annote = {added by A.Eliseev 25.01.2019},
author = {Higgins, Steven I and Scheiter, Simon},
doi = {10.1038/nature11238},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7410},
pages = {209--212},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Atmospheric CO2 forces abrupt vegetation shifts locally, but not globally}},
url = {https://doi.org/10.1038/nature11238 https://www.nature.com/articles/nature11238{\#}supplementary-information http://www.nature.com/articles/nature11238},
volume = {488},
year = {2012}
}
@article{Hirota232,
abstract = {It has been suggested that tropical forest and savanna could represent alternative stable states, implying critical transitions at tipping points in response to altered climate or other drivers. So far, evidence for this idea has remained elusive, and integrated climate models assume smooth vegetation responses. We analyzed data on the distribution of tree cover in Africa, Australia, and South America to reveal strong evidence for the existence of three distinct attractors: forest, savanna, and a treeless state. Empirical reconstruction of the basins of attraction indicates that the resilience of the states varies in a universal way with precipitation. These results allow the identification of regions where forest or savanna may most easily tip into an alternative state, and they pave the way to a new generation of coupled climate models.},
annote = {added by A.Eliseev 25.01.2019},
author = {Hirota, Marina and Holmgren, Milena and {Van Nes}, Egbert H and Scheffer, Marten},
doi = {10.1126/science.1210657},
issn = {0036-8075},
journal = {Science},
month = {oct},
number = {6053},
pages = {232--235},
publisher = {American Association for the Advancement of Science},
title = {{Global resilience of tropical forest and savanna to critical transitions}},
url = {http://science.sciencemag.org/content/334/6053/232 http://www.sciencemag.org/cgi/doi/10.1126/science.1210657},
volume = {334},
year = {2011}
}
@article{Hmiel2020,
abstract = {Atmospheric methane (CH4) is a potent greenhouse gas, and its mole fraction has more than doubled since the preindustrial era1. Fossil fuel extraction and use are among the largest anthropogenic sources of CH4 emissions, but the precise magnitude of these contributions is a subject of debate2,3. Carbon-14 in CH4 (14CH4) can be used to distinguish between fossil (14C-free) CH4 emissions and contemporaneous biogenic sources; however, poorly constrained direct 14CH4 emissions from nuclear reactors have complicated this approach since the middle of the 20th century4,5. Moreover, the partitioning of total fossil CH4 emissions (presently 172 to 195 teragrams CH4 per year)2,3 between anthropogenic and natural geological sources (such as seeps and mud volcanoes) is under debate; emission inventories suggest that the latter account for about 40 to 60 teragrams CH4 per year6,7. Geological emissions were less than 15.4 teragrams CH4 per year at the end of the Pleistocene, about 11,600 years ago8, but that period is an imperfect analogue for present-day emissions owing to the large terrestrial ice sheet cover, lower sea level and extensive permafrost. Here we use preindustrial-era ice core 14CH4 measurements to show that natural geological CH4 emissions to the atmosphere were about 1.6 teragrams CH4 per year, with a maximum of 5.4 teragrams CH4 per year (95 per cent confidence limit)—an order of magnitude lower than the currently used estimates. This result indicates that anthropogenic fossil CH4 emissions are underestimated by about 38 to 58 teragrams CH4 per year, or about 25 to 40 per cent of recent estimates. Our record highlights the human impact on the atmosphere and climate, provides a firm target for inventories of the global CH4 budget, and will help to inform strategies for targeted emission reductions},
author = {Hmiel, Benjamin and Petrenko, V. V. and Dyonisius, M. N. and Buizert, C. and Smith, A. M. and Place, P. F. and Harth, C. and Beaudette, R. and Hua, Q. and Yang, B. and Vimont, I. and Michel, S. E. and Severinghaus, J. P. and Etheridge, D. and Bromley, T. and Schmitt, J. and Fa{\"{i}}n, X. and Weiss, R. F. and Dlugokencky, E.},
doi = {10.1038/s41586-020-1991-8},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7795},
pages = {409--412},
title = {{Preindustrial 14CH4 indicates greater anthropogenic fossil CH4 emissions}},
url = {http://www.nature.com/articles/s41586-020-1991-8},
volume = {578},
year = {2020}
}
@article{Hoffman2014,
author = {Hoffman, F. M. and Randerson, J. T. and Arora, V. K. and Bao, Q. and Cadule, P. and Ji, D. and Jones, C. D. and Kawamiya, M. and Khatiwala, S. and Lindsay, K. and Obata, A. and Shevliakova, E. and Six, K. D. and Tjiputra, J. F. and Volodin, E. M. and Wu, T.},
doi = {10.1002/2013JG002381},
issn = {21698953},
journal = {Journal of Geophysical Research: Biogeosciences},
keywords = {Intergovernmental Panel on Climate Change (IPCC),carbon cycle feedbacks,climate,climate warming,greenhouse gases,terrestrial and oceanic carbon sinks,uncertainty quantification},
month = {feb},
number = {2},
pages = {141--162},
publisher = {Wiley-Blackwell},
title = {{Causes and implications of persistent atmospheric carbon dioxide biases in Earth System Models}},
url = {http://doi.wiley.com/10.1002/2013JG002381},
volume = {119},
year = {2014}
}
@article{Holden2018b,
abstract = {Western United States wildfire increases have been generally attributed to warming temperatures, either through effects on winter snowpack or summer evaporation. However, near-surface air temperature and evaporative demand are strongly influenced by moisture availability and these interactions and their role in regulating fire activity have never been fully explored. Here we show that previously unnoted declines in summer precipitation from 1979 to 2016 across 31–45{\%} of the forested areas in the western United States are strongly associated with burned area variations. The number of wetting rain days (WRD; days with precipitation ≥2.54 mm) during the fire season partially regulated the temperature and subsequent vapor pressure deficit (VPD) previously implicated as a primary driver of annual wildfire area burned. We use path analysis to decompose the relative influence of declining snowpack, rising temperatures, and declining precipitation on observed fire activity increases. After accounting for interactions, the net effect of WRD anomalies on wildfire area burned was more than 2.5 times greater than the net effect of VPD, and both the WRD and VPD effects were substantially greater than the influence of winter snowpack. These results suggest that precipitation during the fire season exerts the strongest control on burned area either directly through its wetting effects or indirectly through feedbacks to VPD. If these trends persist, decreases in summer precipitation and the associated summertime aridity increases would lead to more burned area across the western United States with far-reaching ecological and socioeconomic impacts.},
author = {Holden, Zachary A. and Swanson, Alan and Luce, Charles H. and Jolly, W. Matt and Maneta, Marco and Oyler, Jared W. and Warren, Dyer A. and Parsons, Russell and Affleck, David},
doi = {10.1073/pnas.1802316115},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Climate change,Hydrology,Wildfire},
month = {sep},
number = {36},
pages = {E8349--E8357},
title = {{Decreasing fire season precipitation increased recent western US forest wildfire activity}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1802316115},
volume = {115},
year = {2018}
}
@article{Holl2020a,
author = {Holl, Karen D and Brancalion, Pedro H S},
doi = {10.1126/science.aba8232},
issn = {0036-8075},
journal = {Science},
number = {6491},
pages = {580--581},
publisher = {American Association for the Advancement of Science},
title = {{Tree planting is not a simple solution}},
volume = {368},
year = {2020}
}
@article{bg-17-2853-2020,
author = {Holl, D and Pfeiffer, E.-M. and Kutzbach, L},
doi = {10.5194/bg-17-2853-2020},
journal = {Biogeosciences},
number = {10},
pages = {2853--2874},
title = {{Comparison of eddy covariance CO2 and CH4 fluxes from mined and recently rewetted sections in a northwestern German cutover bog}},
url = {https://bg.copernicus.org/articles/17/2853/2020/},
volume = {17},
year = {2020}
}
@article{Hoogakker2015,
abstract = {During the last and penultimate glacial maxima, atmospheric CO2 concentrations were lower than present, possibly in part because of increased storage of respired carbon in the deep oceans1. The amount of respired carbon present in a water mass can be calculated from its oxygen content through apparent oxygen utilization; the oxygen content can in turn be calculated from the carbon isotope gradient within the sediment column2. Here we analyse the shells of benthic foraminifera occurring at the sediment surface and the oxic/anoxic interface on the Portuguese Margin to reconstruct the carbon isotope gradient and hence bottom-water oxygenation over the past 150,000 years. We find that bottom-water oxygen concentrations were 45 and 65 $\mu$mol kg−1 lower than present during the last and penultimate glacial maxima, respectively. We calculate that concentrations of remineralized organic carbon were at least twice as high as today during the glacial maxima. We attribute these changes to decreased ventilation linked to a reorganization of ocean circulation3 and a strengthened global biological pump4. If the respired carbon pool was of a similar size throughout the entire glacial deep Atlantic basin, then this sink could account for 15 and 20 per cent of the glacial PCO2 drawdown during the last and penultimate glacial maxima.},
author = {Hoogakker, Babette A. A. and Elderfield, Henry and Schmiedl, Gerhard and McCave, I. Nick and Rickaby, Rosalind E. M.},
doi = {10.1038/ngeo2317},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jan},
number = {1},
pages = {40--43},
title = {{Glacial–interglacial changes in bottom-water oxygen content on the Portuguese margin}},
url = {http://www.nature.com/articles/ngeo2317},
volume = {8},
year = {2015}
}
@article{Hoogakker2018a,
author = {Hoogakker, Babette A. A. and Lu, Zunli and Umling, Natalie and Jones, Luke and Zhou, Xiaoli and Rickaby, Rosalind E. M. and Thunell, Robert and Cartapanis, Olivier and Galbraith, Eric},
doi = {10.1038/s41586-018-0589-x},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7727},
pages = {410--413},
title = {{Glacial expansion of oxygen-depleted seawater in the eastern tropical Pacific}},
url = {http://www.nature.com/articles/s41586-018-0589-x},
volume = {562},
year = {2018}
}
@article{Hopcroft2017,
abstract = {Atmospheric methane (CH 4) varied with climate during the Quaternary, rising from a concentration of 375 p.p.b.v. during the last glacial maximum (LGM) 21,000 years ago, to 680 p.p.b.v. at the beginning of the industrial revolution. However, the causes of this increase remain unclear; proposed hypotheses rely on fluctuations in either the magnitude of CH 4 sources or CH 4 atmospheric lifetime, or both. Here we use an Earth System model to provide a comprehensive assessment of these competing hypotheses, including estimates of uncertainty. We show that in this model, the global LGM CH 4 source was reduced by 28-46{\%}, and the lifetime increased by 2-8{\%}, with a best-estimate LGM CH 4 concentration of 463-480 p.p.b.v. Simulating the observed LGM concentration requires a 46-49{\%} reduction in sources, indicating that we cannot reconcile the observed amplitude. This highlights the need for better understanding of the effects of low CO 2 and cooler climate on wetlands and other natural CH 4 sources.},
author = {Hopcroft, Peter O. and Valdes, Paul J. and O'Connor, Fiona M. and Kaplan, Jed O. and Beerling, David J.},
doi = {10.1038/ncomms14383},
issn = {20411723},
journal = {Nature Communications},
pages = {14383},
pmid = {28220787},
title = {{Understanding the glacial methane cycle}},
volume = {8},
year = {2017}
}
@article{Hopwood2020,
author = {Hopwood, M J and Carroll, D and Dunse, T and Hodson, A and Holding, J M and Iriarte, J L and Ribeiro, S and Achterberg, E P and Cantoni, C and Carlson, D F and Chierici, M and Clarke, J S and Cozzi, S and Fransson, A and Juul-Pedersen, T and Winding, M H S and Meire, L},
doi = {10.5194/tc-14-1347-2020},
journal = {The Cryosphere},
number = {4},
pages = {1347--1383},
title = {{Review article: How does glacier discharge affect marine biogeochemistry and primary production in the Arctic?}},
url = {https://tc.copernicus.org/articles/14/1347/2020/},
volume = {14},
year = {2020}
}
@article{Horowitz2020,
abstract = {Abstract Marine cloud brightening (MCB) is proposed to offset global warming by emitting sea salt aerosols to the tropical marine boundary layer, which increases aerosol and cloud albedo. Sea salt aerosol is the main source of tropospheric reactive chlorine (Cly) and bromine (Bry). The effects of additional sea salt on atmospheric chemistry have not been explored. We simulate sea salt aerosol injections for MCB under two scenarios (212–569 Tg/a) in the GEOS-Chem global chemical transport model, only considering their impacts as a halogen source. Globally, tropospheric Cly and Bry increase (20–40$\backslash${\%}), leading to decreased ozone (−3 to −6$\backslash${\%}). Consequently, OH decreases (−3 to −5$\backslash${\%}), which increases the methane lifetime (3–6$\backslash${\%}). Our results suggest that the chemistry of the additional sea salt leads to minor total radiative forcing compared to that of the sea salt aerosol itself ({\~{}}2$\backslash${\%}) but may have potential implications for surface ozone pollution in tropical coastal regions.},
author = {Horowitz, Hannah M and Holmes, Christopher and Wright, Alicia and Sherwen, Tom{\'{a}}s and Wang, Xuan and Evans, Mat and Huang, Jiayue and Jaegl{\'{e}}, Lyatt and Chen, Qianjie and Zhai, Shuting and Alexander, Becky},
doi = {10.1029/2019GL085838},
journal = {Geophysical Research Letters},
number = {4},
pages = {e2019GL085838},
title = {{Effects of Sea Salt Aerosol Emissions for Marine Cloud Brightening on Atmospheric Chemistry: Implications for Radiative Forcing}},
volume = {47},
year = {2020}
}
@article{Hossaini2016,
author = {Hossaini, Ryan and Chipperfield, Martyn P. and Saiz-Lopez, Alfonso and Fernandez, Rafael and Monks, Sarah and Feng, Wuhu and Brauer, Peter and von Glasow, Roland},
doi = {10.1002/2016JD025756},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {dec},
number = {23},
pages = {14271--14297},
title = {{A global model of tropospheric chlorine chemistry: Organic versus inorganic sources and impact on methane oxidation}},
url = {http://doi.wiley.com/10.1002/2016JD025756},
volume = {121},
year = {2016}
}
@article{Houghton2017,
abstract = {The net flux of carbon from land use and land cover change (LULCC) is an important term in the global carbon balance. Here we report a new estimate of annual fluxes from 1850 to 2015, updating earlier analyses with new estimates of both historical and current rates of LULCC and including emissions from draining and burning of peatlands in Southeast Asia. For most of the 186 countries included we relied on data from Food and Agriculture Organization to document changes in the areas of croplands and pastures since 1960 and changes in the areas of forests and “other land” since 1990. For earlier years we used other sources of information. We used a bookkeeping model that prescribed changes in carbon density of vegetation and soils for 20 types of ecosystems and five land uses. The total net flux attributable to LULCC over the period 1850–2015is calculated tohavebeen145±16 PgC(1 standard deviation).Mostof the emissionswerefromthe tropics (102±5.8 Pg C), generally increasing over time to a maximum of 2.10 PgCyr?1 in 1997. Outside the tropics emissions were roughly constant at 0.5 PgCyr?1 until 1940, declined to zero around 1970, and then became negative. For the most recent decade (2006–2015) global net emissions from LULCC averaged 1.11 (±0.35) PgCyr?1, consisting of a net source from the tropics (1.41±0.17 PgCyr?1), a net sink in northern midlatitudes (?0.28±0.21 PgCyr?1), and carbon neutrality in southern midlatitudes},
author = {Houghton, R. A. and Nassikas, Alexander A.},
doi = {10.1002/2016GB005546},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {mar},
number = {3},
pages = {456--472},
title = {{Global and regional fluxes of carbon from land use and land cover change 1850–2015}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016GB005546 http://doi.wiley.com/10.1002/2016GB005546},
volume = {31},
year = {2017}
}
@article{Houghton2013,
abstract = {This study proposes that carbon fluxes identified as being from land use and land-cover change (LULCC) include only that component of a flux that can be attributed to LULCC, exclusive of the effects of environmental change (CO2 , climate, N, etc.). This proposal seems too obvious to need saying, but published estimates of the LULCC flux are widely variable for reasons that have more to do with modeling environmental effects than with LULCC.},
author = {Houghton, Richard A.},
doi = {10.1111/gcb.12233},
isbn = {1354-1013 (Print)$\backslash$r1354-1013 (Linking)},
issn = {13541013},
journal = {Global Change Biology},
keywords = {Carbon,Carbon models,Environmental change,Land use,Land-cover change,UNFCCC},
month = {sep},
number = {9},
pages = {2609--2612},
pmid = {23625734},
title = {{Keeping management effects separate from environmental effects in terrestrial carbon accounting}},
url = {http://doi.wiley.com/10.1111/gcb.12233},
volume = {19},
year = {2013}
}
@article{Houweling2015,
abstract = {This study presents the outcome of an inverse modeling intercomparison experiment on the use of total column CO2 retrievals from Greenhouse Gas Observing Satellite (GOSAT) for quantifying global sources and sinks of CO2. Eight research groups submitted inverse modeling results for the first year of GOSAT measurements. Inversions were carried out using only GOSAT data, a combination of GOSAT and surface measurements, and using only surface measurements. As expected, the most robust flux estimates are obtained at large scales (e.g., within 20{\%} of the annual flux at the global scale), and they quickly diverge toward the scale of the subcontinental TRANSCOM regions and beyond (to {\textgreater}100{\%} of the annual flux). We focus our analysis on a shift in the CO2 uptake over land from the Tropics toward the Northern Hemisphere Extra tropics of ∼1 PgC/yr when GOSAT data are used in the inversions. This shift is largely driven by TRANSCOM regions Europe and Northern Africa, showing, respectively, an increased uptake and release of 0.7 and 0.9 PgC/yr. Inversions using GOSAT data show a reduced gradient between midlatitudes of the Northern Hemisphere and the Tropics, consistent with the latitudinal shift in carbon uptake. However, the reduced gradients degrade the agreement with background aircraft and surface measurements. To narrow the range of inversion-derived flux, estimates will require further efforts to understand the differences not only between the retrieval schemes but also between inverse models, as their contributions to the overall uncertainty are estimated to be of similar magnitude.},
author = {Houweling, S. and Baker, D. and Basu, S. and Boesch, H. and Butz, A. and Chevallier, F. and Deng, F. and Dlugokencky, E. J. and Feng, L. and Ganshin, A. and Hasekamp, O. and Jones, D. and Maksyutov, S. and Marshall, J. and Oda, T. and O'Dell, C. W. and Oshchepkov, S. and Palmer, P. I. and Peylin, P. and Poussi, Z. and Reum, F. and Takagi, H. and Yoshida, Y. and Zhuravlev, R.},
doi = {10.1002/2014JD022962},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {may},
number = {10},
pages = {5253--5266},
title = {{An intercomparison of inverse models for estimating sources and sinks of CO2 using GOSAT measurements}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014JD022962 http://doi.wiley.com/10.1002/2014JD022962},
volume = {120},
year = {2015}
}
@article{Hovenden2019a,
author = {Hovenden, Mark J. and Leuzinger, Sebastian and Newton, Paul C. D. and Fletcher, Andrew and Fatichi, Simone and L{\"{u}}scher, Andreas and Reich, Peter B. and Andresen, Louise C. and Beier, Claus and Blumenthal, Dana M. and Chiariello, Nona R. and Dukes, Jeffrey S. and Kellner, Juliane and Hofmockel, Kirsten and Niklaus, Pascal A. and Song, Jian and Wan, Shiqiang and Classen, Aim{\'{e}}e T. and Langley, J. Adam},
doi = {10.1038/s41477-018-0356-x},
issn = {2055-0278},
journal = {Nature Plants},
month = {feb},
number = {2},
pages = {167--173},
title = {{Globally consistent influences of seasonal precipitation limit grassland biomass response to elevated CO2}},
volume = {5},
year = {2019}
}
@article{Howard2017,
author = {Howard, Jennifer and McLeod, Elizabeth and Thomas, Sebastian and Eastwood, Erin and Fox, Matthew and Wenzel, Lauren and Pidgeon, Emily},
doi = {10.1002/aqc.2809},
issn = {10527613},
journal = {Aquatic Conservation: Marine and Freshwater Ecosystems},
month = {sep},
pages = {100--115},
title = {{The potential to integrate blue carbon into MPA design and management}},
url = {http://doi.wiley.com/10.1002/aqc.2809},
volume = {27},
year = {2017}
}
@article{Howarth2019,
author = {Howarth, Robert W.},
doi = {10.5194/bg-16-3033-2019},
issn = {1726-4189},
journal = {Biogeosciences},
keywords = {howarth2019},
month = {aug},
number = {15},
pages = {3033--3046},
title = {{Ideas and perspectives: is shale gas a major driver of recent increase in global atmospheric methane?}},
url = {https://bg.copernicus.org/articles/16/3033/2019/},
volume = {16},
year = {2019}
}
@article{Hristov2013a,
abstract = {The goal of this review was to analyze published data related to mitigation of enteric methane (CH4) emissions from ruminant animals to document the most effective and sustainable strategies. Increasing forage digestibility and digestible forage intake was one of the major recommended CH4 mitigation practices. Although responses vary, CH4 emissions can be reduced when corn silage replaces grass silage in the diet. Feeding legume silages could also lower CH4 emissions compared to grass silage due to their lower fiber concentration. Dietary lipids can be effective in reducing CH4 emissions, but their applicability will depend on effects on feed intake, fiber digestibility, production, and milk composition. Inclusion of concentrate feeds in the diet of ruminants will likely decrease CH4 emission intensity (Ei; CH4 per unit animal product), particularly when inclusion is above 40{\%} of dietary dry matter and rumen function is not impaired. Supplementation of diets containing medium to poor quality forages with small amounts of concentrate feed will typically decrease CH4 Ei. Nitrates show promise as CH4 mitigation agents, but more studies are needed to fully understand their impact on whole-farm greenhouse gas emissions, animal productivity, and animal health. Through their effect on feed efficiency and rumen stoichiometry, ionophores are likely to have a moderate CH4 mitigating effect in ruminants fed high-grain or mixed grain-forage diets. Tannins may also reduce CH4 emissions although in some situations intake and milk production may be compromised. Some direct-fed microbials, such as yeast-based products, might have a moderate CH4-mitigating effect through increasing animal productivity and feed efficiency, but the effect is likely to be inconsistent. Vaccines against rumen archaea may offer mitigation opportunities in the future although the extent of CH4 reduction is likely to be small and adaptation by ruminal microbes and persistence of the effect is unknown. Overall, improving forage quality and the overall efficiency of dietary nutrient use is an effective way of decreasing CH4 Ei. Several feed supplements have a potential to reduce CH4 emission from ruminants although their long-term effect has not been well established and some are toxic or may not be economically feasible.},
author = {Hristov, A. N. and Oh, J. and Firkins, J. L. and Dijkstra, J. and Kebreab, E. and Waghorn, G. and Makkar, H. P. S. and Adesogan, A. T. and Yang, W. and Lee, C. and Gerber, P. J. and Henderson, B. and Tricarico, J. M.},
doi = {10.2527/jas.2013-6583},
issn = {0021-8812},
journal = {Journal of Animal Science},
month = {nov},
number = {11},
pages = {5045--5069},
pmid = {24045497},
title = {{Mitigation of methane and nitrous oxide emissions from animal operations: I. A review of enteric methane mitigation options}},
volume = {91},
year = {2013}
}
@article{Hu2016,
abstract = {Estimates of global riverine nitrous oxide (N2O) emissions contain great uncertainty. We conducted a meta‐analysis incorporating 169 observations from published literature to estimate global riverine N2O emission rates and emission factors. Riverine N2O flux was significantly correlated with NH4, NO3 and DIN (NH4 + NO3) concentrations, loads and yields. The emission factors EF(a) (i.e., the ratio of N2O emission rate and DIN load) and EF(b) (i.e., the ratio of N2O and DIN concentrations) values were comparable and showed negative correlations with nitrogen concentration, load and yield and water discharge, but positive correlations with the dissolved organic carbon : DIN ratio. After individually evaluating 82 potential regression models based on EF(a) or EF(b) for global, temperate zone and subtropical zone datasets, a power function of DIN yield multiplied by watershed area was determined to provide the best fit between modeled and observed riverine N2O emission rates (EF(a): R2 = 0.92 for both global and climatic zone models, n = 70; EF(b): R2 = 0.91 for global model and R2 = 0.90 for climatic zone models, n = 70). Using recent estimates of DIN loads for 6400 rivers, models estimated global riverine N2O emission rates of 29.6–35.3 (mean = 32.2) Gg N2O–N yr−1 and emission factors of 0.16–0.19{\%} (mean = 0.17{\%}). Global riverine N2O emission rates are forecasted to increase by 35{\%}, 25{\%}, 18{\%} and 3{\%} in 2050 compared to the 2000s under the Millennium Ecosystem Assessment's Global Orchestration, Order from Strength, Technogarden, and Adapting Mosaic scenarios, respectively. Previous studies may overestimate global riverine N2O emission rates (300–2100 Gg N2O–N yr−1) because they ignore declining emission factor values with increasing nitrogen levels and channel size, as well as neglect differences in emission factors corresponding to different nitrogen forms. Riverine N2O emission estimates will be further enhanced through refining emission factor estimates, extending measurements longitudinally along entire river networks and improving estimates of global riverine nitrogen loads.},
author = {Hu, Minpeng and Chen, Dingjiang and Dahlgren, Randy A.},
doi = {10.1111/gcb.13351},
issn = {13541013},
journal = {Global Change Biology},
month = {nov},
number = {11},
pages = {3566--3582},
publisher = {Wiley/Blackwell (10.1111)},
title = {{Modeling nitrous oxide emission from rivers: a global assessment}},
url = {http://doi.wiley.com/10.1111/gcb.13351},
volume = {22},
year = {2016}
}
@article{doi:10.1029/2009JG001270,
abstract = {Recent climatic warming has resulted in pronounced environmental changes in the Arctic, including shrub cover expansion and sea ice shrinkage. These changes foreshadow more dramatic impacts that will occur if the warming trend continues. Among the major challenges in anticipating these impacts are “surprises” stemming from changes in system components that have remained relatively stable in the historic record. Tundra burning is potentially one such component. Here we report paleoecological evidence showing that recent tundra burning is unprecedented in the central Alaskan Arctic within the last 5000 years. Analysis of lake sediment cores reveals peak values of charcoal accumulation corresponding to the Anaktuvuk River Fire in 2007, with no evidence of other fire events throughout the past five millennia in that area. Atmospheric reanalysis suggests that the fire was favored by exceptionally warm and dry weather conditions in summer and early autumn. Boosted regression tree modeling shows that such conditions also explain 95{\%} of the interannual variability in tundra area burned throughout Alaska over the past 60 years and that the response of tundra burning to climatic warming is nonlinear. These results contribute to an emerging body of evidence suggesting that tundra ecosystems can burn more frequently under suitable climatic and fuel conditions. The Anaktuvuk River Fire coincides with extreme sea ice retreat, and tundra area burned in Alaska is moderately correlated with sea ice extent from 1979 to 2009 (r = −0.43, p = 0.02). Recurrences of large tundra fires as a result of sea ice disappearance may represent a novel manifestation of coupled marine-terrestrial responses to climatic warming.},
author = {Hu, Feng Sheng and Higuera, Philip E and Walsh, John E and Chapman, William L and Duffy, Paul A and Brubaker, Linda B and Chipman, Melissa L},
doi = {10.1029/2009JG001270},
journal = {Journal of Geophysical Research: Biogeosciences},
keywords = {Arctic,charcoal records,climatic warming,paleoecology,sea ice retreat,tundra fire},
number = {G4},
pages = {G04002},
title = {{Tundra burning in Alaska: Linkages to climatic change and sea ice retreat}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2009JG001270},
volume = {115},
year = {2010}
}
@article{Hua2016b,
abstract = {Reforestation is a critical means of addressing the environmental and social problems of deforestation. China's Grain-for-Green Program (GFGP) is the world's largest reforestation scheme. Here we provide the first nationwide assessment of the tree composition of GFGP forests and the first combined ecological and economic study aimed at understanding GFGP's biodiversity implications. Across China, GFGP forests are overwhelmingly monocultures or compositionally simple mixed forests. Focusing on birds and bees in Sichuan Province, we find that GFGP reforestation results in modest gains (via mixed forest) and losses (via monocultures) of bird diversity, along with major losses of bee diversity. Moreover, all current modes of GFGP reforestation fall short of restoring biodiversity to levels approximating native forests. However, even within existing modes of reforestation, GFGP can achieve greater biodiversity gains by promoting mixed forests over monocultures; doing so is unlikely to entail major opportunity costs or pose unforeseen economic risks to households.},
author = {Hua, Fangyuan and Wang, Xiaoyang and Zheng, Xinlei and Fisher, Brendan and Wang, Lin and Zhu, Jianguo and Tang, Ya and Yu, Douglas W and Wilcove, David S},
doi = {10.1038/ncomms12717},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {12717},
title = {{Opportunities for biodiversity gains under the world's largest reforestation programme}},
volume = {7},
year = {2016}
}
@article{Huang2019a,
abstract = {Biochar amendment is a good means of mitigating methane (CH4) and nitrous oxide (N2O) emissions. However, the effects of biochar amendment on N2O and CH4 reduction in soil under rotation with different soil moisture contents is not well understood. To understand CH4 and N2O flux from soil with biochar amendment under water-unsaturated and water-saturated conditions, a field experiment was conducted in a tobacco-rice rotation field in subtropical China to investigate N2O and CH4 emissions following soil amendment with tobacco straw biochar at rates of 0, 10, 40 and 80 t{\textperiodcentered}ha−1 (B0, B10, B40 and B80, respectively). N2O and CH4 emissions were monitored by a closed-chamber method in the water-unsaturated tobacco (UT) and water-saturated rice (SR) seasons during the 2015 planting season. The soil pH increased from 5.4 in the control to 6.1 in the soil amended with biochar at 80 t{\textperiodcentered}ha−1 in the UT season. During both the UT and SR seasons, with biochar amendment at 40 and 80 t{\textperiodcentered}ha−1, the soil bulk density (BD) decreased, while the soil organic matter (SOM) and available potassium (Av. K) contents increased. N2O flux was significantly greater in UT than in SR in the controls but decreased with the application of biochar during both the UT and SR seasons. The cumulative CH4 emission decreased with the rate of biochar application and the methanotroph pmoA gene copy number in soils and increased with the methanogenic archaea 16Sr DNA gene copy number in soils during the rice-cropping season. These results indicated that biochar amendment could decrease methanogenic archaea and increase of methanotroph pmoA gene, which are the mechanistic origin for CH4 reduction.},
author = {Huang, Yibin and Wang, Chengji and Lin, Cheng and Zhang, Yushu and Chen, Xi and Tang, Lina and Liu, Cenwei and Chen, Qingrong and Onwuka, Mabel Ifeoma and Song, Tieying},
doi = {10.1038/s41598-019-53044-1},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {17277},
title = {{Methane and Nitrous Oxide Flux after Biochar Application in Subtropical Acidic Paddy Soils under Tobacco-Rice Rotation}},
url = {https://doi.org/10.1038/s41598-019-53044-1},
volume = {9},
year = {2019}
}
@article{Hugelius2014,
abstract = {Abstract. Soils and other unconsolidated deposits in the northern circumpolar permafrost region store large amounts of soil organic carbon (SOC). This SOC is potentially vulnerable to remobilization following soil warming and permafrost thaw, but SOC stock estimates were poorly constrained and quantitative error estimates were lacking. This study presents revised estimates of permafrost SOC stocks, including quantitative uncertainty estimates, in the 0–3 m depth range in soils as well as for sediments deeper than 3 m in deltaic deposits of major rivers and in the Yedoma region of Siberia and Alaska. Revised estimates are based on significantly larger databases compared to previous studies. Despite this there is evidence of significant remaining regional data gaps. Estimates remain particularly poorly constrained for soils in the High Arctic region and physiographic regions with thin sedimentary overburden (mountains, highlands and plateaus) as well as for deposits below 3 m depth in deltas and the Yedoma region. While some components of the revised SOC stocks are similar in magnitude to those previously reported for this region, there are substantial differences in other components, including the fraction of perennially frozen SOC. Upscaled based on regional soil maps, estimated permafrost region SOC stocks are 217 ± 12 and 472 ± 27 Pg for the 0–0.3 and 0–1 m soil depths, respectively (±95{\%} confidence intervals). Storage of SOC in 0–3 m of soils is estimated to 1035 ± 150 Pg. Of this, 34 ± 16 Pg C is stored in poorly developed soils of the High Arctic. Based on generalized calculations, storage of SOC below 3 m of surface soils in deltaic alluvium of major Arctic rivers is estimated as 91 ± 52 Pg. In the Yedoma region, estimated SOC stocks below 3 m depth are 181 ± 54 Pg, of which 74 ± 20 Pg is stored in intact Yedoma (late Pleistocene ice- and organic-rich silty sediments) with the remainder in refrozen thermokarst deposits. Total estimated SOC storage for the permafrost region is {\&}sim;1300 Pg with an uncertainty range of {\&}sim;1100 to 1500 Pg. Of this, {\&}sim;500 Pg is in non-permafrost soils, seasonally thawed in the active layer or in deeper taliks, while {\&}sim;800 Pg is perennially frozen. This represents a substantial {\&}sim;300 Pg lowering of the estimated perennially frozen SOC stock compared to previous estimates.},
author = {Hugelius, G and Strauss, J and Zubrzycki, S and Harden, J W and Schuur, E A G and Ping, C.-L. and Schirrmeister, L and Grosse, G and Michaelson, G J and Koven, C D and O{\&}apos;Donnell, J. A. and Elberling, B and Mishra, U and Camill, P and Yu, Z and Palmtag, J and Kuhry, P},
doi = {10.5194/bg-11-6573-2014},
issn = {1726-4189},
journal = {Biogeosciences},
month = {dec},
number = {23},
pages = {6573--6593},
title = {{Estimated stocks of circumpolar permafrost carbon with quantified uncertainty ranges and identified data gaps}},
url = {http://www.biogeosciences.net/11/6573/2014/ https://www.biogeosciences.net/11/6573/2014/},
volume = {11},
year = {2014}
}
@article{Humphrey2018,
abstract = {Land ecosystems absorb on average 30 per cent of anthropogenic carbon dioxide (CO2) emissions, thereby slowing the increase of CO2 concentration in the atmosphere1. Year-to-year variations in the atmospheric CO2 growth rate are mostly due to fluctuating carbon uptake by land ecosystems1. The sensitivity of these fluctuations to changes in tropical temperature has been well documented2,3,4,5,6, but identifying the role of global water availability has proved to be elusive. So far, the only usable proxies for water availability have been time-lagged precipitation anomalies and drought indices3,4,5, owing to a lack of direct observations. Here, we use recent observations of terrestrial water storage changes derived from satellite gravimetry7 to investigate terrestrial water effects on carbon cycle variability at global to regional scales. We show that the CO2 growth rate is strongly sensitive to observed changes in terrestrial water storage, drier years being associated with faster atmospheric CO2 growth. We demonstrate that this global relationship is independent of known temperature effects and is underestimated in current carbon cycle models. Our results indicate that interannual fluctuations in terrestrial water storage strongly affect the terrestrial carbon sink and highlight the importance of the interactions between the water and carbon cycles.},
author = {Humphrey, Vincent and Zscheischler, Jakob and Ciais, Philippe and Gudmundsson, Lukas and Sitch, Stephen and Seneviratne, Sonia I},
doi = {10.1038/s41586-018-0424-4},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7720},
pages = {628--631},
publisher = {Nature Publishing Group},
title = {{Sensitivity of atmospheric CO2 growth rate to observed changes in terrestrial water storage}},
url = {https://www.nature.com/articles/s41586-018-0424-4 http://www.nature.com/articles/s41586-018-0424-4},
volume = {560},
year = {2018}
}
@article{Hungate2013,
author = {Hungate, Bruce A. and Dijkstra, Paul and Wu, Zhuoting and Duval, Benjamin D. and Day, Frank P. and Johnson, Dale W. and Megonigal, J. Patrick and Brown, Alisha L. P. and Garland, Jay L.},
doi = {10.1111/nph.12333},
issn = {0028646X},
journal = {New Phytologist},
month = {nov},
number = {3},
pages = {753--766},
title = {{Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO2 exposure in a subtropical oak woodland}},
url = {http://doi.wiley.com/10.1111/nph.12333},
volume = {200},
year = {2013}
}
@article{HUNTER2013105,
abstract = {The global submarine inventory of methane hydrate is thought to be considerable. The stability of marine hydrates is sensitive to changes in temperature and pressure and once destabilised, hydrates release methane into sediments and ocean and potentially into the atmosphere, creating a positive feedback with climate change. Here we present results from a multi-model study investigating how the methane hydrate inventory dynamically responds to different scenarios of future climate and sea level change. The results indicate that a warming-induced reduction is dominant even when assuming rather extreme rates of sea level rise (up to 20 mm yr−1) under moderate warming scenarios (RCP 4.5). Over the next century modelled hydrate dissociation is focussed in the top of Arctic and Subarctic sediments beneath water depth. Predicted dissociation rates are particularly sensitive to the modelled vertical hydrate distribution within sediments. Under the worst case business-as-usual scenario (RCP 8.5), upper estimates of resulting global sea-floor methane fluxes could exceed estimates of natural global fluxes by 2100 , although subsequent oxidation in the water column could reduce peak atmospheric release rates to 0.75–1.4 Tg CH4 yr−1.},
author = {Hunter, S.J. and Goldobin, D.S. and Haywood, A.M. and Ridgwell, A and Rees, J.G.},
doi = {10.1016/j.epsl.2013.02.017},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {anthropogenic,climate change,methane hydrate},
month = {apr},
pages = {105--115},
title = {{Sensitivity of the global submarine hydrate inventory to scenarios of future climate change}},
url = {http://www.sciencedirect.com/science/article/pii/S0012821X13000848 https://linkinghub.elsevier.com/retrieve/pii/S0012821X13000848},
volume = {367},
year = {2013}
}
@article{Huntingford2013a,
annote = {added by A.Eliseev 25.01.2019},
author = {Huntingford, Chris and Zelazowski, Przemyslaw and Galbraith, David and Mercado, Lina M and Sitch, Stephen and Fisher, Rosie and Lomas, Mark and Walker, Anthony P and Jones, Chris D and Booth, Ben B B and Malhi, Yadvinder and Hemming, Debbie and Kay, Gillian and Good, Peter and Lewis, Simon L and Phillips, Oliver L and Atkin, Owen K and Lloyd, Jon and Gloor, Emanuel and Zaragoza-Castells, Joana and Meir, Patrick and Betts, Richard and Harris, Phil P and Nobre, Carlos and Marengo, Jose and Cox, Peter M},
doi = {10.1038/ngeo1741},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {apr},
number = {4},
pages = {268--273},
publisher = {Nature Publishing Group},
title = {{Simulated resilience of tropical rainforests to CO2-induced climate change}},
url = {https://doi.org/10.1038/ngeo1741 https://www.nature.com/articles/ngeo1741{\#}supplementary-information http://www.nature.com/articles/ngeo1741},
volume = {6},
year = {2013}
}
@article{Huntingford2017,
abstract = {Land-atmosphere exchanges influence atmospheric CO2. Emphasis has been on describing photosynthetic CO2 uptake, but less on respiration losses. New global datasets describe upper canopy dark respiration (Rd) and temperature dependencies. This allows characterisation of baseline Rd, instantaneous temperature responses and longer-term thermal acclimation effects. Here we show the global implications of these parameterisations with a global gridded land model. This model aggregates Rd to whole-plant respiration Rp, driven with meteorological forcings spanning uncertainty across climate change models. For pre-industrial estimates, new baseline Rd increases Rp and especially in the tropics. Compared to new baseline, revised instantaneous response decreases Rp for mid-latitudes, while acclimation lowers this for the tropics with increases elsewhere. Under global warming, new Rd estimates amplify modelled respiration increases, although partially lowered by acclimation. Future measurements will refine how Rd aggregates to whole-plant respiration. Our analysis suggests Rp could be around 30{\%} higher than existing estimates.},
author = {Huntingford, Chris and Atkin, Owen K and {Martinez-de la Torre}, Alberto and Mercado, Lina M and Heskel, Mary A and Harper, Anna B and Bloomfield, Keith J and O'Sullivan, Odhran S and Reich, Peter B and Wythers, Kirk R and Butler, Ethan E and Chen, Ming and Griffin, Kevin L and Meir, Patrick and Tjoelker, Mark G and Turnbull, Matthew H and Sitch, Stephen and Wiltshire, Andy and Malhi, Yadvinder},
doi = {10.1038/s41467-017-01774-z},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {1602},
title = {{Implications of improved representations of plant respiration in a changing climate}},
url = {https://doi.org/10.1038/s41467-017-01774-z http://www.nature.com/articles/s41467-017-01774-z},
volume = {8},
year = {2017}
}
@article{Huntzinger2017a,
abstract = {Terrestrial ecosystems play a vital role in regulating the accumulation of carbon (C) in the atmosphere. Understanding the factors controlling land C uptake is critical for reducing uncertainties in projections of future climate. The relative importance of changing climate, rising atmospheric CO2, and other factors, however, remains unclear despite decades of research. Here, we use an ensemble of land models to show that models disagree on the primary driver of cumulative C uptake for 85{\%} of vegetated land area. Disagreement is largest in model sensitivity to rising atmospheric CO2 which shows almost twice the variability in cumulative land uptake since 1901 (1 s.d. of 212.8 PgC vs. 138.5 PgC, respectively). We find that variability in CO2 and temperature sensitivity is attributable, in part, to their compensatory effects on C uptake, whereby comparable estimates of C uptake can arise by invoking different sensitivities to key environmental conditions. Conversely, divergent estimates of C uptake can occur despite being based on the same environmental sensitivities. Together, these findings imply an important limitation to the predictability of C cycling and climate under unprecedented environmental conditions. We suggest that the carbon modeling community prioritize a probabilistic multi-model approach to generate more robust C cycle projections.},
author = {Huntzinger, D. N. and Michalak, A. M. and Schwalm, C. and Ciais, P. and King, A. W. and Fang, Y. and Schaefer, K. and Wei, Y. and Cook, R. B. and Fisher, J. B. and Hayes, D. and Huang, M. and Ito, A. and Jain, A. K. and Lei, H. and Lu, C. and Maignan, F. and Mao, J. and Parazoo, N. and Peng, S. and Poulter, B. and Ricciuto, D. and Shi, X. and Tian, H. and Wang, W. and Zeng, N. and Zhao, F.},
doi = {10.1038/s41598-017-03818-2},
isbn = {2045-2322},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {4765},
title = {{Uncertainty in the response of terrestrial carbon sink to environmental drivers undermines carbon–climate feedback predictions}},
url = {https://www.nature.com/articles/s41598-017-03818-2 http://www.nature.com/articles/s41598-017-03818-2},
volume = {7},
year = {2017}
}
@article{Hupp2020,
author = {Hupp, Brittany and Kelly, D. Clay},
doi = {10.1029/2020PA004018},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
month = {nov},
number = {11},
pages = {e2020PA004018},
title = {{Delays, Discrepancies, and Distortions: Size-Dependent Sediment Mixing and the Deep-Sea Record of the Paleocene-Eocene Thermal Maximum From ODP Site 690 (Weddell Sea)}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2020PA004018},
volume = {35},
year = {2020}
}
@article{Huppmann2018,
abstract = {Scenarios have supported assessments of the IPCC for decades. A new scenario ensemble and a suite of visualization and analysis tools is now made available alongside the IPCC 1.5 °C Special Report to improve transparency and re-use of scenario data across research communities.},
author = {Huppmann, Daniel and Rogelj, Joeri and Kriegler, Elmar and Krey, Volker and Riahi, Keywan},
doi = {10.1038/s41558-018-0317-4},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {dec},
number = {12},
pages = {1027--1030},
title = {{A new scenario resource for integrated 1.5 °C research}},
url = {https://doi.org/10.1038/s41558-018-0317-4 http://www.nature.com/articles/s41558-018-0317-4},
volume = {8},
year = {2018}
}
@article{Hurd2018,
abstract = {Ocean acidification is a global phenomenon, but it is overlaid by pronounced regional variability modulated by local physics, chemistry and biology. Recognition of its multifaceted nature and the interplay of acidification with other ocean drivers has led to international and regional initiatives to establish observation networks and develop unifying principles for biological responses. There is growing awareness of the threat presented by ocean acidification to ecosystem services and the socio-economic consequences are becoming increasingly apparent and quantifiable. In this higher-CO2 world, future challenges involve better design and rigorous testing of adaptation, mitigation and intervention options to offset the effects of ocean acidification at scales ranging from local to regional.},
author = {Hurd, Catriona L and Lenton, Andrew and Tilbrook, Bronte and Boyd, Philip W},
doi = {10.1038/s41558-018-0211-0},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {aug},
number = {8},
pages = {686--694},
title = {{Current understanding and challenges for oceans in a higher-CO2 world}},
url = {https://doi.org/10.1038/s41558-018-0211-0 http://www.nature.com/articles/s41558-018-0211-0},
volume = {8},
year = {2018}
}
@article{Hurtt2020,
abstract = {50 times the information content of the datasets used in CMIP5 and are designed to enable new and improved estimates of the combined effects of land use on the global carbon–climate system.]]{\textgreater}},
author = {Hurtt, George C. and Chini, Louise and Sahajpal, Ritvik and Frolking, Steve and Bodirsky, Benjamin L. and Calvin, Katherine and Doelman, Jonathan C. and Fisk, Justin and Fujimori, Shinichiro and {Klein Goldewijk}, Kees and Hasegawa, Tomoko and Havlik, Peter and Heinimann, Andreas and Humpen{\"{o}}der, Florian and Jungclaus, Johan and Kaplan, Jed O. and Kennedy, Jennifer and Krisztin, Tam{\'{a}}s and Lawrence, David and Lawrence, Peter and Ma, Lei and Mertz, Ole and Pongratz, Julia and Popp, Alexander and Poulter, Benjamin and Riahi, Keywan and Shevliakova, Elena and Stehfest, Elke and Thornton, Peter and Tubiello, Francesco N. and van Vuuren, Detlef P. and Zhang, Xin},
doi = {10.5194/gmd-13-5425-2020},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {nov},
number = {11},
pages = {5425--5464},
title = {{Harmonization of global land use change and management for the period 850–2100 (LUH2) for CMIP6}},
url = {https://gmd.copernicus.org/articles/13/5425/2020/},
volume = {13},
year = {2020}
}
@article{Huybers2017,
author = {Huybers, Peter and Langmuir, Charles H.},
doi = {10.1016/j.epsl.2016.09.021},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
month = {jan},
pages = {238--249},
title = {{Delayed CO2 emissions from mid-ocean ridge volcanism as a possible cause of late-Pleistocene glacial cycles}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X16305015},
volume = {457},
year = {2017}
}
@techreport{IEA2017,
address = {Paris, France},
author = {IEA},
doi = {10.1787/co2_fuel-2017-en},
isbn = {9789264278196},
pages = {529},
publisher = {International Energy Agency (IEA)},
title = {{CO2 Emissions from Fuel Combustion 2017}},
year = {2017}
}
@article{Iida2015a,
author = {Iida, Yosuke and Kojima, Atsushi and Takatani, Yusuke and Nakano, Toshiya and Sugimoto, Hiroyuki and Midorikawa, Takashi and Ishii, Masao},
doi = {10.1007/s10872-015-0306-4},
issn = {0916-8370},
journal = {Journal of Oceanography},
month = {dec},
number = {6},
pages = {637--661},
title = {{Trends in pCO2 and sea–air CO2 flux over the global open oceans for the last two decades}},
url = {http://link.springer.com/10.1007/s10872-015-0306-4},
volume = {71},
year = {2015}
}
@article{Iida2020,
abstract = {Ocean acidification is likely to impact marine ecosystems and human societies adversely and is a carbon cycle issue of great concern. Projecting the degree of ocean acidification and the carbon-climate feedback will require understanding the current status, variability, and trends of ocean inorganic carbon system variables and the ocean carbon sink. With this goal in mind, we reconstructed total alkalinity (TA), dissolved inorganic carbon (DIC), CO2 partial pressure (pCO2sea), sea–air CO2 flux, pH, and aragonite saturation state ($\Omega$arg) for the global ocean based on measurements of pCO2sea and TA. We used a multiple linear regression approach to derive relationships to explain TA and DIC and obtained monthly 1° × 1° gridded values of TA and DIC for the period 1993–2018. These data were converted to pCO2sea, pH, and $\Omega$arg, and monthly sea-air CO2 fluxes were obtained in combination with atmospheric CO2. Mean annual sea–air CO2 flux and its rate of change were estimated to be − 2.0 ± 0.5 PgC year−1 and − 0.3 (PgC year−1) decade−1, respectively. Our analysis revealed that oceanic CO2 uptake decreased during the 1990s and has been increasing since 2000. Our estimate of the globally averaged rate of pH change, − 0.0181 ± 0.0001 decade−1, was consistent with that expected from the trend of atmospheric CO2 growth. However, rates of decline of pH were relatively slow in the Southern Ocean (− 0.0165 ± 0.0001{\textperiodcentered}decade−1) and in the western equatorial Pacific (− 0.0148 ± 0.0002{\textperiodcentered}decade−1). Our estimate of the globally averaged rate of pH change can be used to verify Indicator 14.3.1 of Sustainable Development Goals.},
author = {Iida, Yosuke and Takatani, Yusuke and Kojima, Atsushi and Ishii, Masao},
doi = {10.1007/s10872-020-00571-5},
issn = {0916-8370},
journal = {Journal of Oceanography},
month = {apr},
number = {2},
pages = {323--358},
title = {{Global trends of ocean CO2 sink and ocean acidification: an observation-based reconstruction of surface ocean inorganic carbon variables}},
url = {https://doi.org/10.1007/s10872-020-00571-5 https://link.springer.com/10.1007/s10872-020-00571-5},
volume = {77},
year = {2021}
}
@article{https://doi.org/10.1029/2020GL090695,
abstract = {Abstract Inter-annual to decadal variability in the strength of the land and ocean carbon sinks impede accurate predictions of year-to-year atmospheric carbon dioxide (CO2) growth rate. Such information is crucial to verify the effectiveness of fossil fuel emissions reduction measures. Using a multi-model framework comprising prediction systems initialized by the observed state of the physical climate, we find a predictive skill for the global ocean carbon sink of up to 6 years for some models. Longer regional predictability horizons are found across single models. On land, a predictive skill of up to 2 years is primarily maintained in the tropics and extra-tropics enabled by the initialization of the physical climate. We further show that anomalies of atmospheric CO2 growth rate inferred from natural variations of the land and ocean carbon sinks are predictable at lead time of 2 years and the skill is limited by the land carbon sink predictability horizon.},
annote = {e2020GL090695 2020GL090695},
author = {Ilyina, T and Li, H and Spring, A and M{\"{u}}ller, W A and Bopp, L and Chikamoto, M O and Danabasoglu, G and Dobrynin, M and Dunne, J and Fransner, F and Friedlingstein, P and Lee, W and Lovenduski, N S and Merryfield, W J and Mignot, J and Park, J Y and S{\'{e}}f{\'{e}}rian, R and Sospedra-Alfonso, R and Watanabe, M and Yeager, S},
doi = {https://doi.org/10.1029/2020GL090695},
journal = {Geophysical Research Letters},
keywords = {atmospheric CO2,carbon sinks,predictions},
number = {6},
pages = {e2020GL090695},
title = {{Predictable Variations of the Carbon Sinks and Atmospheric CO2 Growth in a Multi-Model Framework}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020GL090695},
volume = {48},
year = {2021}
}
@techreport{IOC2018,
address = {Paris, France},
author = {IOC},
pages = {17},
publisher = {Intergovernmental Oceanographic Commission (IOC)},
title = {{Indicator Methodology for 14.3.1}},
url = {http://goa-on.org/resources/sdg{\_}14.3.1{\_}indicator.php},
year = {2019}
}
@techreport{IBPES2018,
abstract = {The objective of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is to provide Governments, the private sector, and civil society with scientifically credible and independent up-to-date assessments of available knowledge, to make better-informed decisions at the local, regional and international levels. This thematic Assessment of Land Degradation and Restoration has been carried out by 98 selected authors and 7 early career fellows, assisted by 79 contributing authors, who have analyzed a large body of knowledge, including about 4,000 scientific and other sources. It represents the state of knowledge of land degradation and restoration. Its chapters and their executive summaries were accepted, and its summary for policymakers was approved, by the Plenary of IPBES at its sixth session (18-24 March 2018, Medell{\'{i}}n, Colombia). This Report provides a critical assessment of the full range of issues facing decision makers, including the importance, status, trends and threats to biodiversity and nature's contributions to people, as well as policy and management response options. Establishing the underlying causes of land degradation provides policymakers with the information needed to develop appropriate response options, technologies, policies, financial incentives and behavior changes. The Report recognizes that combatting land degradation, which is a pervasive, systemic phenomenon occurring in all parts of the world, is an urgent priority in order to protect the biodiversity and ecosystem services that are vital to all life on Earth and to ensure human well-being. Land degradation negatively impacts 3.2 billion people, and represents an economic loss in the order of 10{\%} of annual global gross product. The Report concludes that avoiding land degradation and restoring degraded lands makes sound economic sense, resulting in, inter-alia, increased food and water security, increased employment, improved gender equality, and avoidance of conflict and migration. Avoiding land degradation and restoring degraded lands are also essential for meeting the Sustainable Development Goals.},
address = {Bonn, Germany},
author = {IPBES},
doi = {10.5281/zenodo.3237392},
editor = {Montanarella, L. and Scholes, R. and Brainich, A.},
pages = {744},
publisher = {Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)},
title = {{The IPBES assessment report on land degradation and restoration}},
url = {https://www.ipbes.net/assessment-reports/ldr},
year = {2018}
}
@techreport{IPCC2018,
author = {IPCC},
editor = {Masson-Delmotte, V. and Zhai, P. and P{\"{o}}rtner, H.-O. and Roberts, D. and Skea, J. and Shukla, P.R. and Pirani, A. and Moufouma-Okia, W. and P{\'{e}}an, C. and Pidcock, R. and Connors, S. and Matthews, J.B.R. and Chen, Y. and Zhou, X. and Gomis, M.I. and Lonnoy, E. and Maycock, T. and Tignor, M. and Waterfield, T.},
pages = {616},
publisher = {In Press},
title = {{Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change,}},
url = {https://www.ipcc.ch/sr15},
year = {2018}
}
@incollection{IPCC2013j,
address = {Cambridge, United Kingdom and New York, NY, USA},
author = {IPCC},
booktitle = {Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change},
chapter = {SPM},
doi = {10.1017/CBO9781107415324.004},
editor = {Stocker, T.F. and Qin, D. and Plattner, G.-K. and Tignor, M. and Allen, S.K. and Boschung, J. and Nauels, A. and Xia, Y. and Bex, V. and Midgley, P.M.},
isbn = {9781107661820},
pages = {3--29},
publisher = {Cambridge University Press},
title = {{Summary for Policymakers}},
type = {Book Section},
url = {https://www.ipcc.ch/report/ar5/wg1},
year = {2013}
}
@techreport{IPCC2014,
address = {Geneva, Switzerland},
author = {IPCC},
editor = {{Core Writing Team} and Pachauri, R K and Meyer, L A},
pages = {151},
publisher = {IPCC},
title = {{Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change}},
url = {https://www.ipcc.ch/report/ar5/syr},
year = {2014}
}
@techreport{IPCC2019c,
author = {IPCC},
editor = {P{\"{o}}rtner, H.-O. and Roberts, D.C. and Masson-Delmotte, V. and Zhai, P. and Tignor, M. and Poloczanska, E. and Mintenbeck, K. and Alegr{\'{i}}a, A. and Nicolai, M. and Okem, A. and Petzold, J. and Rama, B. and Weyer, N.M.},
pages = {755},
publisher = {In Press},
title = {{IPCC Special Report on the Ocean and Cryosphere in a Changing Climate}},
url = {https://www.ipcc.ch/report/srocc},
year = {2019}
}
@techreport{IPCC2019b,
author = {IPCC},
editor = {Shukla, P.R. and Skea, J. and Buendia, E. Calvo and Masson-Delmotte, V. and P{\"{o}}rtner, H.-O. and Roberts, D.C. and Zhai, P. and Slade, R. and Connors, S. and van Diemen, R. and Ferrat, M. and Haughey, E. and Luz, S. and Neogi, S. and Pathak, M. and Petzold, J. and Pereira, J. Portugal and Vyas, P. and Huntley, E. and Kissick, K. and Belkacemi, M. and Malley, J.},
pages = {896},
publisher = {In Press},
title = {{Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems}},
url = {https://www.ipcc.ch/srccl},
year = {2019}
}
@incollection{IPCC2019a,
author = {IPCC},
booktitle = {IPCC Special Report on the Ocean and Cryosphere in a Changing Climate},
editor = {P{\"{o}}rtner, H.-O. and Roberts, D.C. and Masson-Delmotte, V. and Zhai, P. and Tignor, M. and Poloczanska, E. and Mintenbeck, K. and Nicolai, M. and Okem, A. and Petzold, J. and Rama, B. and Weyer, N.},
pages = {3--35},
publisher = {In Press},
title = {{Summary for Policymakers}},
url = {https://www.ipcc.ch/srocc/chapter/summary-for-policymakers},
year = {2019}
}
@techreport{IPCC2013a,
author = {IPCC},
doi = {10.1017/CBO9781107415324.004},
editor = {Stocker, T.F. and Qin, D. and Plattner, G.-K. and Tignor, M. and Allen, S.K. and Boschung, J. and Nauels, A. and Xia, Y. and Bex, V. and Midgley, P.M.},
isbn = {978-1-107-05799-1},
pages = {1535},
publisher = {Cambridge University Press},
title = {{Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change}},
url = {https://www.ipcc.ch/report/ar5/wg1},
year = {2013}
}
@article{Isabel2020,
abstract = {Abstract Forest ecosystems provide important ecological services and resources, from habitat for biodiversity to the production of environmentally friendly products, and play a key role in the global carbon cycle. Humanity is counting on forests to sequester and store a substantial portion of the anthropogenic carbon dioxide produced globally. However, the unprecedented rate of climate change, deforestation, and accidental importation of invasive insects and diseases are threatening the health and productivity of forests, and their capacity to provide these services. Knowledge of genetic diversity, local adaptation, and genetic control of key traits is required to predict the adaptive capacity of tree populations, inform forest management and conservation decisions, and improve breeding for productive trees that will withstand the challenges of the 21st century. Genomic approaches have well accelerated the generation of knowledge of the genetic and evolutionary underpinnings of nonmodel tree species, and advanced their applications to address these challenges. This special issue of Evolutionary Applications features 14 papers that demonstrate the value of a wide range of genomic approaches that can be used to better understand the biology of forest trees, including species that are widespread and managed for timber production, and others that are threatened or endangered, or serve important ecological roles. We highlight some of the major advances, ranging from understanding the evolution of genomes since the period when gymnosperms separated from angiosperms 300 million years ago to using genomic selection to accelerate breeding for tree health and productivity. We also discuss some of the challenges and future directions for applying genomic tools to address long-standing questions about forest trees.},
annote = {https://doi.org/10.1111/eva.12902},
author = {Isabel, Nathalie and Holliday, Jason A and Aitken, Sally N},
doi = {10.1111/eva.12902},
issn = {1752-4571},
journal = {Evolutionary Applications},
keywords = {assisted gene flow,cyberinfrastructure,forest management,genomic selection,hybridization,insect and disease resistance,landscape genomics,nonmodel species,tree breeding},
month = {jan},
number = {1},
pages = {3--10},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Forest genomics: Advancing climate adaptation, forest health, productivity, and conservation}},
url = {https://doi.org/10.1111/eva.12902},
volume = {13},
year = {2020}
}
@article{Ishidoya2012,
author = {Ishidoya, Shigeyuki and Aoki, Shuji and Goto, Daisuke and Nakazawa, Takakiyo and Taguchi, Shoichi and Patra, PrabirK.},
doi = {10.3402/tellusb.v64i0.18964},
issn = {1600-0889},
journal = {Tellus B: Chemical and Physical Meteorology},
month = {jan},
number = {1},
pages = {18964},
title = {{Time and space variations of the O2/N2 ratio in the troposphere over Japan and estimation of the global CO2 budget for the period 2000–2010}},
url = {https://www.tandfonline.com/doi/full/10.3402/tellusb.v64i0.18964},
volume = {64},
year = {2012}
}
@article{Ishii,
abstract = {Identifying ocean acidification and its controlling mechanisms is an important priority within the broader question of understanding how sustained anthropogenic CO2 emissions are harming the health of ocean. Through extensive analysis of observational data products for ocean inorganic carbon, here we quantify the rate at which acidification is occurring in the western tropical Pacific Warm Pool, revealing -0.0013 ±0.0001 yr-1 for pH and -0.0083±0.0007 yr-1 for the saturation index of aragonite for the years 1985-2016. However, the mean rate of total dissolved inorganic carbon increase (+0.81 ±0.06 µmol kg-1 yr-1) sustaining acidification was {\~{}}20{\%} slower than what would be expected if it were simply controlled by the rate of atmospheric CO2 increase and transmitted through local air-sea CO2 equilibration. Joint Lagrangian and Eulerian model diagnostics indicate that the acidification of the Warm Pool occurs primarily through the anthropogenic CO2 that invades the ocean in the extra-tropics, is transported to the tropics through the thermocline shallow overturning circulation, and then re-emerges into surface waters within the tropics through the Equatorial Undercurrent from below. An interior residence time of several years to decades, acting in conjunction with the accelerating CO2 growth in the atmosphere, can be expected to contribute to modulating the rate of Warm Pool acidification.},
author = {Ishii, Masao and Rodgers, Keith B. and Inoue, Hisayuki Y. and Toyama, Katsuya and Sasano, Daisuke and Kosugi, Naohiro and Ono, Hisashi and Enyo, Kazutaka and Nakano, Toshiya and Iudicone, Daniele and Blanke, Bruno and Aumont, Olivier and Feely, Richard A.},
doi = {10.1029/2019GB006368},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {Equatorial Undercurrent,ocean acidification,shallow meridional overturning circulations,western tropical Pacific Warm Pool},
month = {aug},
number = {8},
pages = {e2019GB006368},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Ocean Acidification From Below in the Tropical Pacific}},
url = {https://doi.org/10.1029/2019GB006368 https://onlinelibrary.wiley.com/doi/10.1029/2019GB006368},
volume = {34},
year = {2020}
}
@article{Ishijima2007,
abstract = {Histories of atmospheric N2O concentration and its $\delta$15N and $\delta$18O were reconstructed for the period 1952–2001 on the basis of the analyses of firn air collected at the North Greenland Ice Core Project (NGRIP), Greenland, and Dome Fuji and H72, Antarctica. The N2O concentration increased from 290 ppbv in 1952 to 316 ppbv in 2001, which agrees well with the results from atmospheric observations and polar ice core analyses. The $\delta$15N and $\delta$18O showed a secular decrease, the respective values being 8.9 and 21.5‰ in 1952 and 7.0 and 20.5‰ in 2001. Their rates of change also varied, from about −0.02‰ yr−1 in the 1950s to about −0.04‰ yr−1 in 1960–2001 for $\delta$15N, and from about 0‰ yr−1 to −0.02‰ yr−1 for $\delta$18O. The isotopic budgetary calculations using a two‐box model indicated that anthropogenic N2O emission from soils played a main role in the atmospheric N2O increase after industrialization, as well as that the average isotopic ratio of anthropogenic N2O has potentially been changed temporally.},
author = {Ishijima, Kentaro and Sugawara, Satoshi and Kawamura, Kenji and Hashida, Gen and Morimoto, Shinji and Murayama, Shohei and Aoki, Shuji and Nakazawa, Takakiyo},
doi = {10.1029/2006JD007208},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Atmospheres},
month = {feb},
number = {D3},
pages = {D03305},
publisher = {Wiley-Blackwell},
title = {{Temporal variations of the atmospheric nitrous oxide concentration and its $\delta$15N and $\delta$18O for the latter half of the 20th century reconstructed from firn air analyses}},
url = {http://doi.wiley.com/10.1029/2006JD007208},
volume = {112},
year = {2007}
}
@article{Ito2017a,
abstract = {Abstract Historic observations of dissolved oxygen (O2) in the ocean are analyzed to quantify multidecadal trends and variability from 1958 to 2015. Additional quality control is applied, and the resultant oxygen anomaly field is used to quantify upper ocean O2 trends at global and hemispheric scales. A widespread negative O2 trend is beginning to emerge from the envelope of interannual variability. Ocean reanalysis data are used to evaluate relationships with changes in ocean heat content (OHC) and oxygen solubility (O2,sat). Global O2 decline is evident after the 1980s, accompanied by an increase in global OHC. The global upper ocean O2 inventory (0?1000 m) changed at the rate of ?243 ± 124 T mol O2 per decade. Further, the O2 inventory is negatively correlated with the OHC (r = ?0.86; 0?1000 m) and the regression coefficient of O2 to OHC is approximately ?8.2 ± 0.66 nmol O2 J?1, on the same order of magnitude as the simulated O2-heat relationship typically found in ocean climate models. Variability and trends in the observed upper ocean O2 concentration are dominated by the apparent oxygen utilization component with relatively small contributions from O2,sat. This indicates that changing ocean circulation, mixing, and/or biochemical processes, rather than the direct thermally induced solubility effects, are the primary drivers for the observed O2 changes. The spatial patterns of the multidecadal trend include regions of enhanced ocean deoxygenation including the subpolar North Pacific, eastern boundary upwelling systems, and tropical oxygen minimum zones. Further studies are warranted to understand and attribute the global O2 trends and their regional expressions.},
annote = {doi: 10.1002/2017GL073613},
author = {Ito, Takamitsu and Minobe, Shoshiro and Long, Matthew C and Deutsch, Curtis},
doi = {10.1002/2017GL073613},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {biogeochemical cycling,climate change,climate impacts,data analysis,global warming,marine chemistry},
month = {may},
number = {9},
pages = {4214--4223},
publisher = {Wiley-Blackwell},
title = {{Upper ocean O2 trends: 1958–2015}},
url = {https://doi.org/10.1002/2017GL073613 http://doi.wiley.com/10.1002/2017GL073613},
volume = {44},
year = {2017}
}
@article{Ito2015,
abstract = {Abstract We investigate the mechanisms controlling the evolution of Southern Ocean carbon storage under a future climate warming scenario. A subset of Coupled Model Intercomparison Project Phase 5 models predicts that the inventory of biologically sequestered carbon south of 40°S increases about 18?34?Pg?C by 2100 relative to the preindustrial condition. Sensitivity experiments with an ocean circulation and biogeochemistry model illustrates the impacts of the wind and buoyancy forcings under a warming climate. Intensified and poleward shifted westerly wind strengthens the upper overturning circulation, not only leading to an increased uptake of anthropogenic CO2 but also releasing biologically regenerated carbon to the atmosphere. Freshening of Antarctic Surface Water causes a slowdown of the lower overturning circulation, leading to an increased Southern Ocean biological carbon storage. The rectified effect of these processes operating together is the sustained growth of the carbon storage in the Southern Ocean, even under the warming climate with a weaker global ocean carbon uptake.},
annote = {doi: 10.1002/2015GL064320},
author = {Ito, Takamitsu and Bracco, Annalisa and Deutsch, Curtis and Frenzel, Hartmut and Long, Matthew and Takano, Yohei},
doi = {10.1002/2015GL064320},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {CMIP-5,MITgcm,Southern Ocean,climate change,ocean carbon uptake},
month = {jun},
number = {11},
pages = {4516--4522},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Sustained growth of the Southern Ocean carbon storage in a warming climate}},
url = {https://doi.org/10.1002/2015GL064320 http://doi.wiley.com/10.1002/2015GL064320},
volume = {42},
year = {2015}
}
@article{Ito2020,
author = {Ito, Akihiko},
doi = {10.1016/j.polar.2020.100558},
issn = {18739652},
journal = {Polar Science},
keywords = {ito2020},
month = {aug},
pages = {100558},
title = {{Bottom-up evaluation of the regional methane budget of northern lands from 1980 to 2015}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1873965220300670},
volume = {27},
year = {2020}
}
@article{Ito2019,
abstract = {The global carbon budget of terrestrial ecosystems is chiefly determined by major flows of carbon dioxide (CO2) such as photosynthesis and respiration, but various minor flows exert considerable influence in determining carbon stocks and their turnover. This study assessed the effects of eight minor carbon flows on the terrestrial carbon budget using a process-based model, the Vegetation Integrative SImulator for Trace gases (VISIT), which included non-CO2 carbon flows, such as methane and biogenic volatile organic compound (BVOC) emissions and subsurface carbon exports and disturbances such as biomass burning, land-use changes, and harvest activities. The range of model-associated uncertainty was evaluated through parameter-ensemble simulations and the results were compared with corresponding observational and modeling studies. In the historical period of 1901 2016, the VISIT simulation indicated that the minor flows substantially influenced terrestrial carbon stocks, flows, and budgets. The simulations estimated mean net ecosystem production in 2000 2009 as 3.21±1.1 PgC yr-1 without minor flows and 6.85±0.9 PgC yr-1 with minor flows. Including minor carbon flows yielded an estimated net biome production of 1.62±1.0 PgC yr-1 in the same period. Biomass burning, wood harvest, export of organic carbon by water erosion, and BVOC emissions had impacts on the global terrestrial carbon budget amounting to around 1 Pg Cyr-1 with specific interannual variabilities. After including the minor flows, ecosystem carbon storage was suppressed by about 440 Pg C, and its mean residence time was shortened by about 2.4 years. The minor flows occur heterogeneously over the land, such that BVOC emission, subsurface export, and wood harvest occur mainly in the tropics, and biomass burning occurs extensively in boreal forests. They also differ in their decadal trends, due to differences in their driving factors. Aggregating the simulation results by land-cover type, cropland fraction, and annual precipitation yielded more insight into the contributions of these minor flows to the terrestrial carbon budget. Considering their substantial and unique roles, these minor flows should be taken into account in the global carbon budget in an integrated manner.},
author = {Ito, Akihiko},
doi = {10.5194/esd-10-685-2019},
issn = {21904987},
journal = {Earth System Dynamics},
number = {4},
pages = {685--709},
title = {{Disequilibrium of terrestrial ecosystem CO2 budget caused by disturbance-induced emissions and non-CO2 carbon export flows: A global model assessment}},
volume = {10},
year = {2019}
}
@article{Iudicone2016,
abstract = {The shallow overturning circulation of the oceans transports heat from the tropics to the mid-latitudes. This overturning also influences the uptake and storage of anthropogenic carbon (Cant). We demonstrate this by quantifying the relative importance of ocean thermodynamics, circulation and biogeochemistry in a global biochemistry and circulation model. Almost 2/3 of the Cant ocean uptake enters via gas exchange in waters that are lighter than the base of the ventilated thermocline. However, almost 2/3 of the excess Cant is stored below the thermocline. Our analysis shows that subtropical waters are a dominant component in the formation of subpolar waters and that these water masses essentially form a common Cant reservoir. This new method developed and presented here is intrinsically Lagrangian, as it by construction only considers the velocity or transport of waters across isopycnals. More generally, our approach provides an integral framework for linking ocean thermodynamics with biogeochemistry.},
author = {Iudicone, Daniele and Rodgers, Keith B and Plancherel, Yves and Aumont, Olivier and Ito, Takamitsu and Key, Robert M and Madec, Gurvan and Ishii, Masao},
doi = {10.1038/srep35473},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {35473},
title = {{The formation of the ocean's anthropogenic carbon reservoir}},
url = {https://doi.org/10.1038/srep35473},
volume = {6},
year = {2016}
}
@article{Jaccard2016,
abstract = {No single mechanism can account for the full amplitude of past atmospheric carbon dioxide (CO2) concentration variability over glacial–interglacial cycles1. A build-up of carbon in the deep ocean has been shown to have occurred during the Last Glacial Maximum2,3. However, the mechanisms responsible for the release of the deeply sequestered carbon to the atmosphere at deglaciation, and the relative importance of deep ocean sequestration in regulating millennial-timescale variations in atmospheric CO2 concentration before the Last Glacial Maximum, have remained unclear. Here we present sedimentary redox-sensitive trace-metal records from the Antarctic Zone of the Southern Ocean that provide a reconstruction of transient changes in deep ocean oxygenation and, by inference, respired carbon storage throughout the last glacial cycle. Our data suggest that respired carbon was removed from the abyssal Southern Ocean during the Northern Hemisphere cold phases of the deglaciation, when atmospheric CO2 concentration increased rapidly, reflecting—at least in part—a combination of dwindling iron fertilization by dust and enhanced deep ocean ventilation. Furthermore, our records show that the observed covariation between atmospheric CO2 concentration and abyssal Southern Ocean oxygenation was maintained throughout most of the past 80,000 years. This suggests that on millennial timescales deep ocean circulation and iron fertilization in the Southern Ocean played a consistent role in modifying atmospheric CO2 concentration.},
author = {Jaccard, Samuel L and Galbraith, Eric D and Mart{\'{i}}nez-Garc{\'{i}}a, Alfredo and Anderson, Robert F},
doi = {10.1038/nature16514},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7589},
pages = {207--210},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Covariation of deep Southern Ocean oxygenation and atmospheric CO2 through the last ice age}},
url = {http://dx.doi.org/10.1038/nature16514 10.1038/nature16514 http://www.nature.com/articles/nature16514},
volume = {530},
year = {2016}
}
@article{Jaccard2014,
author = {Jaccard, Samuel L. and Galbraith, Eric D. and Fr{\"{o}}licher, Thomas L. and Gruber, Nicolas},
doi = {10.5670/oceanog.2014.05},
issn = {10428275},
journal = {Oceanography},
month = {mar},
number = {1},
pages = {26--35},
title = {{Ocean (de)oxygenation across the last deglaciation: insights for the future}},
url = {https://tos.org/oceanography/article/ocean-deoxygenation-across-the-last-deglaciation-insights-for-the-future},
volume = {27},
year = {2014}
}
@article{Jaccard2012,
abstract = {During the last glacial termination, the solubility of gases in the ocean decreased as ocean temperatures rose. However, marine sediments have not unanimously recorded ocean deoxygenation throughout this time. Some records show increasing oxygenation since the Last Glacial Maximum, particularly in the deep sea, while many document abrupt oxygenation changes, often associated with apparent changes in the formation rate of North Atlantic Deep Water. Here we present a global compilation of marine sediment proxy records that reveals remarkable coherency between regional oxygenation changes throughout deglaciation. The upper ocean generally became less oxygenated, but this general trend included pauses and even reversals, reflecting changes in nutrient supply, respiration rates and ventilation. The most pronounced deoxygenation episode in the upper ocean occurred midway through the deglaciation, associated with a reinvigoration of North Atlantic Deep Water formation. At this time, the upper Indo-Pacific Ocean was less oxygenated than today. Meanwhile, the bulk of the deep ocean became more oxygenated over the deglaciation, reflecting a transfer of respired carbon to the atmosphere. The observed divergence from a simple solubility control emphasizes the degree to which oxygen consumption patterns can be altered by changes in ocean circulation and marine ecosystems.},
author = {Jaccard, Samuel L. and Galbraith, Eric D.},
doi = {10.1038/ngeo1352},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {feb},
number = {2},
pages = {151--156},
title = {{Large climate-driven changes of oceanic oxygen concentrations during the last deglaciation}},
url = {http://www.nature.com/articles/ngeo1352},
volume = {5},
year = {2012}
}
@article{Jackson2017b,
abstract = {Soil organic matter (SOM) anchors global terrestrial productivity and food and fiber supply. SOM retains water and soil nutrients and stores more global carbon than do plants and the atmosphere combined. SOM is also decomposed by microbes, returning CO2, a greenhouse gas, to the atmosphere. Unfortunately, soil carbon stocks have been widely lost or degraded through land use changes and unsustainable forest and agricultural practices. To understand its structure and function and to maintain and restore SOM, we need a better appreciation of soil organic carbon (SOC) saturation capacity and the retention of above- and belowground inputs in SOM. Our analysis suggests root inputs are approximately five times more likely than an equivalent mass of aboveground litter to be stabilized as SOM. Microbes, particularly fungi and bacteria, and soil faunal food webs strongly influence SOM decomposition at shallower depths, whereas mineral associations drive stabilization at depths greater than ∼30 cm. Global uncertaint...},
author = {Jackson, Robert B. and Lajtha, Kate and Crow, Susan E. and Hugelius, Gustaf and Kramer, Marc G. and Pi{\~{n}}eiro, Gervasio},
doi = {10.1146/annurev-ecolsys-112414-054234},
isbn = {978-0-8243-1448-4},
issn = {1543-592X},
journal = {Annual Review of Ecology, Evolution, and Systematics},
month = {nov},
number = {1},
pages = {419--445},
title = {{The ecology of soil carbon: pools, vulnerabilities, and biotic and abiotic controls}},
url = {http://www.annualreviews.org/doi/10.1146/annurev-ecolsys-112414-054234},
volume = {48},
year = {2017}
}
@article{Jackson2020,
author = {Jackson, R B and Saunois, M and Bousquet, P and Canadell, J G and Poulter, B and Stavert, A R and Bergamaschi, P and Niwa, Y and Segers, A and Tsuruta, A},
doi = {10.1088/1748-9326/ab9ed2},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jul},
number = {7},
pages = {071002},
title = {{Increasing anthropogenic methane emissions arise equally from agricultural and fossil fuel sources}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/ab9ed2},
volume = {15},
year = {2020}
}
@article{Jackson2019,
abstract = {Zeolites and other technologies should be evaluated and pursued for reducing methane concentrations in the atmosphere from 1,860 ppb to preindustrial levels of {\~{}}750 ppb. Such a goal of atmospheric restoration provides a positive framework for change at a time when climate action is desperately needed.},
author = {Jackson, R B and Solomon, E I and Canadell, J G and Cargnello, M and Field, C B},
doi = {10.1038/s41893-019-0299-x},
issn = {2398-9629},
journal = {Nature Sustainability},
number = {6},
pages = {436--438},
title = {{Methane removal and atmospheric restoration}},
url = {https://doi.org/10.1038/s41893-019-0299-x},
volume = {2},
year = {2019}
}
@article{Jackson2005,
abstract = {Carbon sequestration strategies highlight tree plantations without considering their full environmental consequences. We combined field research, synthesis of more than 600 observations, and climate and economic modeling to document substantial losses in stream flow, and increased soil salinization and acidification, with afforestation. Plantations decreased stream flow by 227 millimeters per year globally (52{\%}), with 13{\%} of streams drying completely for at least 1 year. Regional modeling of U.S. plantation scenarios suggests that climate feedbacks are unlikely to offset such water losses and could exacerbate them. Plantations can help control groundwater recharge and upwelling but reduce stream flow and salinize and acidify some soils.},
author = {Jackson, Robert B. and Jobb{\'{a}}gy, Esteban G. and Avissar, Roni and Roy, Somnath Baidya and Barrett, Damian J. and Cook, Charles W. and Farley, Kathleen A. and {Le Maitre}, David C. and McCarl, Bruce A. and Murray, Brian C.},
doi = {10.1126/science.1119282},
issn = {00368075},
journal = {Science},
number = {5756},
pages = {1944--1947},
pmid = {16373572},
title = {{Atmospheric science: Trading water for carbon with biological carbon sequestration}},
volume = {310},
year = {2005}
}
@article{Jacobson2007,
abstract = {We have constructed an inverse estimate of surface fluxes of carbon dioxide using both atmospheric and oceanic observational constraints. This global estimate is spatially resolved into 11 land regions and 11 ocean regions, and is calculated as a temporal mean for the period 1992?1996. The method interprets in situ observations of carbon dioxide concentration in the ocean and atmosphere with transport estimates from global circulation models. Uncertainty in the modeled circulation is explicitly considered in this inversion by using a suite of 16 atmospheric and 10 oceanic transport simulations. The inversion analysis, coupled with estimates of river carbon delivery, indicates that the open ocean had a net carbon uptake from the atmosphere during the period 1992?96 of 1.7 PgC yr?1, consisting of an uptake of 2.1 PgC yr?1 of anthropogenic carbon and a natural outgassing of about 0.5 PgC yr?1 of carbon fixed on land and transported through rivers to the open ocean. The formal uncertainty on this oceanic uptake, despite a comprehensive effort to quantify sources of error due to modeling biases, uncertain riverine carbon load, and biogeochemical assumptions, is driven down to 0.2 PgC yr?1 by the large number and relatively even spatial distribution of oceanic observations used. Other sources of error, for which quantifiable estimates are not currently available, such as unresolved transport and large region inversion bias, may increase this uncertainty.},
annote = {doi: 10.1029/2005GB002556},
author = {Jacobson, Andrew R and {Mikaloff Fletcher}, Sara E and Gruber, Nicolas and Sarmiento, Jorge L and Gloor, Manuel},
doi = {10.1029/2005GB002556},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {carbon,inversion},
month = {mar},
number = {1},
pages = {GB1019},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{A joint atmosphere–ocean inversion for surface fluxes of carbon dioxide: 1. Methods and global-scale fluxes}},
url = {https://doi.org/10.1029/2005GB002556 http://doi.wiley.com/10.1029/2005GB002556},
volume = {21},
year = {2007}
}
@article{Jans2018,
abstract = {Integrated assessment model scenarios project rising deployment of biomass-using energy systems in climate change mitigation scenarios. But there is concern that bioenergy deployment will increase competition for land and water resources and obstruct objectives such as nature protection, the preservation of carbon-rich ecosystems, and food security. To study the relative importance of water and land availability as biophysical constraints to bioenergy deployment at a global scale, we use a process-detailed, spatially explicit biosphere model to simulate rain-fed and irrigated biomass plantation supply along with the corresponding water consumption for different scenarios concerning availability of land and water resources. We find that global plantation supplies are mainly limited by land availability and only secondarily by freshwater availability. As a theoretical upper limit, if all suitable lands on Earth, besides land currently used in agriculture, were available for bioenergy plantations (“Food first” scenario), total plantation supply would be in the range 2,010–2,300 EJ/year depending on water availability and use. Excluding all currently protected areas reduces the supply by 60{\%}. Excluding also areas where conversion to biomass plantations causes carbon emissions that might be considered unacceptably high will reduce the total plantation supply further. For example, excluding all areas where soil and vegetation carbon stocks exceed 150 tC/ha (“Carbon threshold savanna” scenario) reduces the supply to 170–290 EJ/year. With decreasing land availability, the amount of water available for irrigation becomes vitally important. In the least restrictive land availability scenario (“Food first”), up to 77{\%} of global plantation biomass supply is obtained without additional irrigation. This share is reduced to 31{\%} for the most restrictive “Carbon threshold savanna” scenario. The results highlight the critical—and geographically varying—importance of co-managing land and water resources if substantial contributions of bioenergy are to be reached in mitigation portfolios.},
author = {Jans, Yvonne and Berndes, G{\"{o}}ran and Heinke, Jens and Lucht, Wolfgang and Gerten, Dieter},
doi = {10.1111/gcbb.12530},
issn = {17571707},
journal = {GCB Bioenergy},
keywords = {biodiversity,bioenergy,climate change,global biosphere model,mitigation},
number = {9},
pages = {628--644},
title = {{Biomass production in plantations: Land constraints increase dependency on irrigation water}},
volume = {10},
year = {2018}
}
@article{Janssens-Maenhout2017,
author = {Janssens-Maenhout, Greet and Crippa, Monica and Guizzardi, Diego and Muntean, Marilena and Schaaf, Edwin and Dentener, Frank and Bergamaschi, Peter and Pagliari, Valerio and Olivier, Jos G. J. and Peters, Jeroen A. H. W. and van Aardenne, John A. and Monni, Suvi and Doering, Ulrike and Petrescu, A. M. Roxana and Solazzo, Efisio and Oreggioni, Gabriel D.},
doi = {10.5194/essd-11-959-2019},
isbn = {8484421589},
issn = {1866-3516},
journal = {Earth System Science Data},
keywords = {Jassens-Maenhout2019},
month = {jul},
number = {3},
pages = {959--1002},
title = {{EDGAR v4.3.2 Global Atlas of the three major greenhouse gas emissions for the period 1970–2012}},
url = {https://essd.copernicus.org/articles/11/959/2019/},
volume = {11},
year = {2019}
}
@article{JEFFERY2016251,
author = {Jeffery, Simon and Verheijen, Frank G.A. and Kammann, Claudia and Abalos, Diego},
doi = {10.1016/j.soilbio.2016.07.021},
issn = {00380717},
journal = {Soil Biology and Biochemistry},
keywords = {Biochar,Greenhouse gas,Meta-analysis,Methane,Soil,Standardised mean difference},
month = {oct},
pages = {251--258},
title = {{Biochar effects on methane emissions from soils: A meta-analysis}},
url = {http://www.sciencedirect.com/science/article/pii/S0038071716301663 https://linkinghub.elsevier.com/retrieve/pii/S0038071716301663},
volume = {101},
year = {2016}
}
@article{Jeffrey2019,
author = {Jeffrey, Luke C. and Reithmaier, Gloria and Sippo, James Z. and Johnston, Scott G. and Tait, Douglas R. and Harada, Yota and Maher, Damien T.},
doi = {10.1111/nph.15995},
issn = {0028-646X},
journal = {New Phytologist},
month = {oct},
number = {1},
pages = {146--154},
title = {{Are methane emissions from mangrove stems a cryptic carbon loss pathway? Insights from a catastrophic forest mortality}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.15995},
volume = {224},
year = {2019}
}
@article{Jeltsch-Thommes2018,
author = {Jeltsch-Th{\"{o}}mmes, Aurich and Battaglia, Gianna and Cartapanis, Olivier and Jaccard, Samuel L and Joos, Fortunat},
doi = {10.5194/cp-15-849-2019},
issn = {1814-9332},
journal = {Climate of the Past},
month = {apr},
number = {2},
pages = {849--879},
title = {{Low terrestrial carbon storage at the Last Glacial Maximum: constraints from multi-proxy data}},
url = {https://www.clim-past-discuss.net/cp-2018-167/ https://www.clim-past.net/15/849/2019/},
volume = {15},
year = {2019}
}
@article{Jenkins2018,
abstract = {The relationship between cumulative CO2 emissions and CO2-induced warming is determined by the Transient Climate Response to Emissions (TCRE), but total anthropogenic warming also depends on non-CO2 forcing, complicating the interpretation of emissions budgets based on CO2 alone. An alternative is to frame emissions budgets in terms of CO2-forcing-equivalent (CO2-fe) emissions—the CO2 emissions that would yield a given total anthropogenic radiative forcing pathway. Unlike conventional “CO2-equivalent” emissions, these are directly related to warming by the TCRE and need to fall to zero to stabilize warming: hence, CO2-fe emissions generalize the concept of a cumulative carbon budget to multigas scenarios. Cumulative CO2-fe emissions from 1870 to 2015 inclusive are found to be 2,900 ± 600 GtCO2-fe, increasing at a rate of 67 ± 9.5 GtCO2-fe/yr. A TCRE range of 0.8–2.5°C per 1,000 GtC implies a total budget for 0.6°C of additional warming above the present decade of 880–2,750 GtCO2-fe, with 1,290 GtCO2-fe implied by the Coupled Model Intercomparison Project Phase 5 median response, corresponding to 19 years' CO2-fe emissions at the current rate.},
author = {Jenkins, S. and Millar, R. J. and Leach, N. and Allen, M. R.},
doi = {10.1002/2017GL076173},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {climate stabilization,cumulative carbon budget,forcing equivalent index,greenhouse gas metric},
month = {mar},
number = {6},
pages = {2795--2804},
publisher = {Blackwell Publishing Ltd},
title = {{Framing Climate Goals in Terms of Cumulative CO2-Forcing-Equivalent Emissions}},
url = {http://doi.wiley.com/10.1002/2017GL076173},
volume = {45},
year = {2018}
}
@article{Ji2015,
author = {Ji, Qixing and Babbin, Andrew R. and Jayakumar, Amal and Oleynik, Sergey and Ward, Bess B.},
doi = {10.1002/2015GL066853},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {dec},
number = {24},
pages = {10755--10764},
title = {{Nitrous oxide production by nitrification and denitrification in the Eastern Tropical South Pacific oxygen minimum zone}},
url = {http://doi.wiley.com/10.1002/2015GL066853},
volume = {42},
year = {2015}
}
@article{Ji2019,
author = {Ji, Qixing and Altabet, Mark A. and Bange, Hermann W. and Graco, Michelle I. and Ma, Xiao and Ar{\'{e}}valo-Mart{\'{i}}nez, Damian L. and Grundle, Damian S.},
doi = {10.5194/bg-16-2079-2019},
issn = {1726-4189},
journal = {Biogeosciences},
month = {may},
number = {9},
pages = {2079--2093},
title = {{Investigating the effect of El Ni{\~{n}}o on nitrous oxide distribution in the eastern tropical South Pacific}},
url = {https://www.biogeosciences.net/16/2079/2019/},
volume = {16},
year = {2019}
}
@incollection{Jia2019,
author = {Jia, G. and Shevliakova, E. and Artaxo, P. and Noblet-Ducoudr{\'{e}}, N. De and Houghton, R. and House, J. and Kitajima, K. and Lennard, C. and Popp, A. and Sirin, A. and Sukumar, R. and Verchot, L.},
booktitle = {Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems.},
editor = {Shukla, P.R. and Skea, J. and Buendia, E. Calvo and Masson-Delmotte, V. and P{\"{o}}rtner, H.-O. and Roberts, D.C. and Zhai, P. and Slade, R. and Connors, S. and van Diemen, R. and Ferrat, M. and Haughey, E. and Luz, S. and Neogi, S. and Pathak, M. and Petzold, J. and Pereira, J. Portugal and Vyas, P. and Huntley, E. and Kissick, K. and Belkacemi, M. and Malley, J.},
pages = {131--248},
publisher = {In Press},
title = {{Land–climate interactions}},
url = {https://www.ipcc.ch/srccl/chapter/chapter-2},
year = {2019}
}
@article{Jiang2020b,
author = {Jiang, Mingkai and Caldararu, Silvia and Zhang, Haiyang and Fleischer, Katrin and Crous, Kristine Y. and Yang, Jinyan and {De Kauwe}, Martin G. and Ellsworth, David S. and Reich, Peter B. and Tissue, David T. and Zaehle, S{\"{o}}nke and Medlyn, Belinda E.},
doi = {10.1111/gcb.15277},
issn = {1354-1013},
journal = {Global Change Biology},
month = {oct},
number = {10},
pages = {5856--5873},
title = {{Low phosphorus supply constrains plant responses to elevated CO2 : A meta‐analysis}},
url = {https://onlinelibrary.wiley.com/doi/10.1111/gcb.15277},
volume = {26},
year = {2020}
}
@article{Jiang2020a,
author = {Jiang, Mingkai and Medlyn, Belinda E. and Drake, John E. and Duursma, Remko A. and Anderson, Ian C. and Barton, Craig V. M. and Boer, Matthias M. and Carrillo, Yolima and Casta{\~{n}}eda-G{\'{o}}mez, Laura and Collins, Luke and Crous, Kristine Y. and {De Kauwe}, Martin G. and dos Santos, Bruna M. and Emmerson, Kathryn M. and Facey, Sarah L. and Gherlenda, Andrew N. and Gimeno, Teresa E. and Hasegawa, Shun and Johnson, Scott N. and K{\"{a}}nnaste, Astrid and Macdonald, Catriona A. and Mahmud, Kashif and Moore, Ben D. and Nazaries, Lo{\"{i}}c and Neilson, Elizabeth H. J. and Nielsen, Uffe N. and Niinemets, {\"{U}}lo and Noh, Nam Jin and Ochoa-Hueso, Ra{\'{u}}l and Pathare, Varsha S. and Pendall, Elise and Pihlblad, Johanna and Pi{\~{n}}eiro, Juan and Powell, Jeff R. and Power, Sally A. and Reich, Peter B. and Renchon, Alexandre A. and Riegler, Markus and Rinnan, Riikka and Rymer, Paul D. and Salom{\'{o}}n, Roberto L. and Singh, Brajesh K. and Smith, Benjamin and Tjoelker, Mark G. and Walker, Jennifer K. M. and Wujeska-Klause, Agnieszka and Yang, Jinyan and Zaehle, S{\"{o}}nke and Ellsworth, David S.},
doi = {10.1038/s41586-020-2128-9},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7802},
pages = {227--231},
title = {{The fate of carbon in a mature forest under carbon dioxide enrichment}},
url = {http://www.nature.com/articles/s41586-020-2128-9},
volume = {580},
year = {2020}
}
@article{Jiang2018a,
abstract = {Solar geoengineering has been proposed as a potential mechanism to counteract global warming. Here we use the University of Victoria Earth System Model (UVic) to simulate the effect of idealized sunshade geoengineering on the global carbon cycle. We conduct two simulations. The first is the A2 simulation, where the model is driven by prescribed emission scenario based on the SRES A2 CO2 emission pathway. The second is the solar geoengineering simulation in which the model is driven by the A2 CO2 emission scenario combined with sunshade solar geoengineering. In the model, solar geoengineering is represented by a spatially uniform reduction in solar insolation that is implemented at year 2020 to offset CO2-induced global mean surface temperature change. Our results show that solar geoengineering increases global carbon uptake relative to A2, in particular CO2 uptake by the terrestrial biosphere. The increase in land carbon uptake is mainly associated with increased net primary production (NPP) in the tropics in the geoengineering simulation, which prevents excess warming in tropics. By year 2100, solar geoengineering decreases A2-simulated atmospheric CO2 by 110 ppm (12{\%}) and causes a 60{\%} (251 Pg C) increase in land carbon accumulation compared to A2. Solar geoengineering also prevents the reduction in ocean oxygen concentration caused by increased ocean temperatures and decreased ocean ventilation, but reduces global ocean NPP. Our results suggest that to fully access the climate effect of solar geoengineering, the response of the global carbon cycle should be taken into account.},
author = {Jiang, Jiu and Zhang, Han and Cao, Long},
doi = {10.1007/s11430-017-9210-0},
issn = {1869-1897},
journal = {Science China Earth Sciences},
number = {9},
pages = {1306--1315},
title = {{Simulated effect of sunshade solar geoengineering on the global carbon cycle}},
volume = {61},
year = {2018}
}
@article{Jiang2019,
abstract = {The ocean's chemistry is changing due to the uptake of anthropogenic carbon dioxide (CO 2 ). This phenomenon, commonly referred to as “Ocean Acidification”, is endangering coral reefs and the broader marine ecosystems. In this study, we combine a recent observational seawater CO 2 data product, i.e., the 6 th version of the Surface Ocean CO 2 Atlas (1991–2018, {\~{}}23 million observations), with temporal trends at individual locations of the global ocean from a robust Earth System Model to provide a high-resolution regionally varying view of global surface ocean pH and the Revelle Factor. The climatology extends from the pre-Industrial era (1750 C.E.) to the end of this century under historical atmospheric CO 2 concentrations (pre-2005) and the Representative Concentrations Pathways (post-2005) of the Intergovernmental Panel on Climate Change (IPCC)'s 5 th Assessment Report. By linking the modeled pH trends to the observed modern pH distribution, the climatology benefits from recent improvements in both model design and observational data coverage, and is likely to provide improved regional OA trajectories than the model output could alone, therefore, will help guide the regional OA adaptation strategies. We show that air-sea CO 2 disequilibrium is the dominant mode of spatial variability for surface pH, and discuss why pH and calcium carbonate mineral saturation states, two important metrics for OA, show contrasting spatial variability.},
author = {Jiang, Li-Qing and Carter, Brendan R and Feely, Richard A and Lauvset, Siv K and Olsen, Are},
doi = {10.1038/s41598-019-55039-4},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {18624},
title = {{Surface ocean pH and buffer capacity: past, present and future}},
url = {https://doi.org/10.1038/s41598-019-55039-4 http://www.nature.com/articles/s41598-019-55039-4},
volume = {9},
year = {2019}
}
@article{Jiang2021,
abstract = {●Elevated atmospheric CO2 (eCa) may benefit plants during drought by reducing stomatal conductance (gs) but any ‘water savings effect' could be neutralized by concurrent stimulation of leaf area. We investigated whether eCa enhanced water savings, thereby ameliorating the impact of drought on carbon and water relations in trees. ●We report leaf‐level gas exchange and whole‐plant and soil water relations during a short‐term dry‐down in two Eucalyptus species with contrasting drought tolerance. Plants had previously been established for 9‐11 months in steady‐state conditions of ambient (aCa) and eCa, with half of each treatment group exposed to sustained drought for 5‐7 months. ●The lower stomatal conductance under eCa did not lead to soil moisture savings during the dry‐down due to the counteractive effect of increased whole‐plant leaf area. Nonetheless, eCa‐grown plants maintained higher photosynthetic rates and leaf water potentials, making them less stressed during the dry‐down, despite being larger. These effects were more pronounced in the xeric species than the mesic species, and in previously water‐stressed plants. ●Our findings indicate that eCa may enhance plant performance during drought despite a lack of soil water savings, especially in species with more conservative growth and water‐use strategies.},
author = {Jiang, Mingkai and Kelly, Jeff W.G. and Atwell, Brian J. and Tissue, David T. and Medlyn, Belinda E.},
doi = {10.1111/nph.17233},
issn = {0028-646X},
journal = {New Phytologist},
keywords = {biomass,co 2 enrichment,drought,drought by reducing stomatal,dry-down,ec a,elevated atmospheric co 2,leaf gas exchange,may benefit plants during,physiology,plant hydraulic,water-savings},
number = {2016},
title = {{Drought by CO2 interactions in trees: a test of the water savings mechanism}},
year = {2021}
}
@article{Jiao2014,
abstract = {Abstract. This paper reviews progress on understanding biological carbon sequestration in the ocean with special reference to the microbial formation and transformation of recalcitrant dissolved organic carbon (RDOC), the microbial carbon pump (MCP). We propose that RDOC is a concept with a wide continuum of recalcitrance. Most RDOC compounds maintain their levels of recalcitrance only in a specific environmental context (RDOCt). The ocean RDOC pool also contains compounds that may be inaccessible to microbes due to their extremely low concentration (RDOCc). This differentiation allows us to appreciate the linkage between microbial source and RDOC composition on a range of temporal and spatial scales. Analyses of biomarkers and isotopic records show intensive MCP processes in the Proterozoic oceans when the MCP could have played a significant role in regulating climate. Understanding the dynamics of the MCP in conjunction with the better constrained biological pump (BP) over geological timescales could help to predict future climate trends. Integration of the MCP and the BP will require new research approaches and opportunities. Major goals include understanding the interactions between particulate organic carbon (POC) and RDOC that contribute to sequestration efficiency, and the concurrent determination of the chemical composition of organic carbon, microbial community composition and enzymatic activity. Molecular biomarkers and isotopic tracers should be employed to link water column processes to sediment records, as well as to link present-day observations to paleo-evolution. Ecosystem models need to be developed based on empirical relationships derived from bioassay experiments and field investigations in order to predict the dynamics of carbon cycling along the stability continuum of POC and RDOC under potential global change scenarios. We propose that inorganic nutrient input to coastal waters may reduce the capacity for carbon sequestration as RDOC. The nutrient regime enabling maximum carbon storage from combined POC flux and RDOC formation should therefore be sought.},
author = {Jiao, N. and Robinson, C. and Azam, F. and Thomas, H. and Baltar, F. and Dang, H. and Hardman-Mountford, N. J. and Johnson, M. and Kirchman, D. L. and Koch, B. P. and Legendre, L. and Li, C. and Liu, J. and Luo, T. and Luo, Y.-W. and Mitra, A. and Romanou, A. and Tang, K. and Wang, X. and Zhang, C. and Zhang, R.},
doi = {10.5194/bg-11-5285-2014},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {19},
pages = {5285--5306},
title = {{Mechanisms of microbial carbon sequestration in the ocean – future research directions}},
url = {https://bg.copernicus.org/articles/11/5285/2014/},
volume = {11},
year = {2014}
}
@article{Jiao2019,
abstract = {The high vapor pressure deficit (VPD) in some arid and semi-arid climates creates undesirable conditions for the growth of tomato plants (Solanum lycopersicum L., cv. Jinpeng). The global CO2 concentration ([CO2]) has also risen in recent years to levels above 400 $\mu$mol{\textperiodcentered}mol−1. However, the coordinated effect of VPD and [CO2] on tomato plant growth remains unclear, especially at VPDs of 5–6 kPa or even higher that are extremely detrimental to plant growth. Here, we explore the interaction of VPD and [CO2] on plant water status, stomatal characteristics, and gas exchange parameters in summer greenhouses in a semi-arid area. Plants were grown in four adjacent glass greenhouses with different environmental conditions: (i) high VPD + low [CO2] representing natural/control conditions; (ii) high VPD + high [CO2] representing enriched CO2; (iii) low VPD + low [CO2] representing reduced VPD; and (iv) low VPD + high [CO2] representing reduced VPD and enriched CO2. Reducing the VPD alleviated the water stress of the plant and increased the gas exchange area of the leaf, which was beneficial to the entry of CO2 into the leaf. At this time, the increase of [CO2] was more beneficial to promote the photosynthetic rate and then improve the water use efficiency and yield.},
author = {Jiao, Xiao Cong and Song, Xiao Ming and Zhang, Da Long and Du, Qing Jie and Li, Jian Ming},
doi = {10.1038/s41598-019-45232-w},
issn = {20452322},
journal = {Scientific Reports},
number = {1},
pages = {1--10},
pmid = {31213627},
publisher = {Springer US},
title = {{Coordination between vapor pressure deficit and CO2 on the regulation of photosynthesis and productivity in greenhouse tomato production}},
url = {http://dx.doi.org/10.1038/s41598-019-45232-w},
volume = {9},
year = {2019}
}
@article{Jickells2017,
abstract = {We report a new synthesis of best estimates of the inputs of fixed nitrogen to the world ocean via atmospheric deposition and compare this to fluvial inputs and dinitrogen fixation. We evaluate the scale of human perturbation of these fluxes. Fluvial inputs dominate inputs to the continental shelf, and we estimate that about 75{\%} of this fluvial nitrogen escapes from the shelf to the open ocean. Biological dinitrogen fixation is the main external source of nitrogen to the open ocean, i.e., beyond the continental shelf. Atmospheric deposition is the primary mechanism by which land-based nitrogen inputs, and hence human perturbations of the nitrogen cycle, reach the open ocean. We estimate that anthropogenic inputs are currently leading to an increase in overall ocean carbon sequestration of {\~{}}0.4{\%} (equivalent to an uptake of 0.15 Pg C yr−1 and less than the Duce et al. (2008) estimate). The resulting reduction in climate change forcing from this ocean CO2 uptake is offset to a small extent by an increase in ocean N2O emissions. We identify four important feedbacks in the ocean atmosphere nitrogen system that need to be better quantified to improve our understanding of the perturbation of ocean biogeochemistry by atmospheric nitrogen inputs. These feedbacks are recycling of (1) ammonia and (2) organic nitrogen from the ocean to the atmosphere and back, (3) the suppression of nitrogen fixation by increased nitrogen concentrations in surface waters from atmospheric deposition, and (4) increased loss of nitrogen from the ocean by denitrification due to increased productivity stimulated by atmospheric inputs.},
author = {Jickells, T D and Buitenhuis, E and Altieri, K and Baker, A R and Capone, D and Duce, R A and Dentener, F and Fennel, K and Kanakidou, M and LaRoche, J and Lee, K and Liss, P and Middelburg, J J and Moore, J K and Okin, G and Oschlies, A and Sarin, M and Seitzinger, S and Sharples, J and Singh, A and Suntharalingam, P and Uematsu, M and Zamora, L M},
doi = {10.1002/2016GB005586},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {0312 Air/sea constituent fluxes,0469 Nitrogen cycling,4805 Biogeochemical cycles,and modelin,atmospheric deposition,nitrogen,ocean,processes},
month = {jan},
number = {2},
pages = {289--305},
title = {{A reevaluation of the magnitude and impacts of anthropogenic atmospheric nitrogen inputs on the ocean}},
url = {http://dx.doi.org/10.1002/2016GB005586 http://doi.wiley.com/10.1002/2016GB005586},
volume = {31},
year = {2017}
}
@article{Jin2015,
abstract = {The area burned by Southern California wildfires has increased in recent decades, with implications for human health, infrastructure, and ecosystem management. Meteorology and fuel structure are universally recognized controllers of wildfire, but their relative importance, and hence the efficacy of abatement and suppression efforts, remains controversial. Southern California's wildfires can be partitioned by meteorology: fires typically occur either during Santa Ana winds (SA fires) in October through April, or warm and dry periods in June through September (non-SA fires). Previous work has not quantitatively distinguished between these fire regimes when assessing economic impacts or climate change influence. Here we separate five decades of fire perimeters into those coinciding with and without SA winds. The two fire types contributed almost equally to burned area, yet SA fires were responsible for 80{\%} of cumulative 1990–2009 economic losses ({\$}3.1 Billion). The damage disparity was driven by fire characteristics: SA fires spread three times faster, occurred closer to urban areas, and burned into areas with greater housing values. Non-SA fires were comparatively more sensitive to age-dependent fuels, often occurred in higher elevation forests, lasted for extended periods, and accounted for 70{\%} of total suppression costs. An improved distinction of fire type has implications for future projections and management. The area burned in non-SA fires is projected to increase 77{\%} (±43{\%}) by the mid-21st century with warmer and drier summers, and the SA area burned is projected to increase 64{\%} (±76{\%}), underscoring the need to evaluate the allocation and effectiveness of suppression investments.},
author = {Jin, Yufang and Goulden, Michael L and Faivre, Nicolas and Veraverbeke, Sander and Sun, Fengpeng and Hall, Alex and Hand, Michael S and Hook, Simon and Randerson, James T},
doi = {10.1088/1748-9326/10/9/094005},
issn = {1748-9326},
journal = {Environmental Research Letters},
number = {9},
pages = {94005},
publisher = {IOP Publishing},
title = {{Identification of two distinct fire regimes in Southern California: implications for economic impact and future change}},
url = {http://dx.doi.org/10.1088/1748-9326/10/9/094005},
volume = {10},
year = {2015}
}
@article{Jokinen2018a,
author = {Jokinen, Sami A and Virtasalo, Joonas J and Jilbert, Tom and Kaiser, J{\'{e}}r{\^{o}}me and Dellwig, Olaf and Arz, Helge W and H{\"{a}}nninen, Jari and Arppe, Laura and Collander, Miia and Saarinen, Timo},
doi = {10.5194/bg-15-3975-2018},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jul},
number = {13},
pages = {3975--4001},
title = {{A 1500-year multiproxy record of coastal hypoxia from the northern Baltic Sea indicates unprecedented deoxygenation over the 20th century}},
volume = {15},
year = {2018}
}
@article{Jolly2015a,
abstract = {Climate strongly influences global wildfire activity, and recent wildfire surges may signal fire weather-induced pyrogeographic shifts. Here we use three daily global climate data sets and three fire danger indices to develop a simple annual metric of fire weather season length, and map spatio-temporal trends from 1979 to 2013. We show that fire weather seasons have lengthened across 29.6 million km{\textless}sup{\textgreater}2{\textless}/sup{\textgreater} (25.3{\%}) of the Earth's vegetated surface, resulting in an 18.7{\%} increase in global mean fire weather season length. We also show a doubling (108.1{\%} increase) of global burnable area affected by long fire weather seasons ({\textgreater}1.0 $\sigma$ above the historical mean) and an increased global frequency of long fire weather seasons across 62.4 million km{\textless}sup{\textgreater}2{\textless}/sup{\textgreater} (53.4{\%}) during the second half of the study period. If these fire weather changes are coupled with ignition sources and available fuel, they could markedly impact global ecosystems, societies, economies and climate.},
author = {Jolly, W. Matt and Cochrane, Mark A. and Freeborn, Patrick H. and Holden, Zachary A. and Brown, Timothy J. and Williamson, Grant J. and Bowman, David M.J.S.},
doi = {10.1038/ncomms8537},
issn = {20411723},
journal = {Nature Communications},
title = {{Climate-induced variations in global wildfire danger from 1979 to 2013}},
year = {2015}
}
@article{Jones2016b,
author = {Jones, C. D. and Ciais, P and Davis, S J and Friedlingstein, P and Gasser, T and Peters, G P and Rogelj, J and van Vuuren, D P and Canadell, J G and Cowie, A and Jackson, R B and Jonas, M and Kriegler, E and Littleton, E and Lowe, J A and Milne, J and Shrestha, G and Smith, P and Torvanger, A and Wiltshire, A},
doi = {10.1088/1748-9326/11/9/095012},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {sep},
number = {9},
pages = {095012},
publisher = {IOP Publishing},
title = {{Simulating the earth system response to negative emissions}},
url = {http://stacks.iop.org/1748-9326/11/i=9/a=095012?key=crossref.6b5747055a178d1c59ffa940adb33091},
volume = {11},
year = {2016}
}
@article{Jones2013b,
abstract = {We have examined changes in climate which result from the sudden termination of geoengineering after 50 years of offsetting a 1{\%} per annum increase in CO2 concentrations by a reduction of solar radiation, as simulated by 11 different climate models in experiment G2 of the Geoengineering Model Intercomparison Project. The models agree on a rapid increase in global-mean temperature following termination accompanied by increases in global-mean precipitation rate and decreases in sea-ice cover. There is no agreement on the impact of geoengineering termination on the rate of change of global-mean plant net primary productivity. There is a considerable degree of consensus for the geographical distribution of temperature change following termination, with faster warming at high latitudes and over land. There is also considerable agreement regarding the distribution of reductions in Arctic sea-ice, but less so for the Antarctic. There is much less agreement regarding the patterns of change in precipitation and net primary productivity, with a greater degree of consensus at higher latitudes.},
author = {Jones, Andy and Haywood, Jim M. and Alterskjaer, Kari and Boucher, Olivier and Cole, Jason N. S. and Curry, Charles L. and Irvine, Peter J. and Ji, Duoying and Kravitz, Ben and {Egill Kristj{\'{a}}nsson}, J{\'{o}}n and Moore, John C. and Niemeier, Ulrike and Robock, Alan and Schmidt, Hauke and Singh, Balwinder and Tilmes, Simone and Watanabe, Shingo and Yoon, Jin-Ho},
doi = {10.1002/jgrd.50762},
isbn = {2169-8996},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {sep},
number = {17},
pages = {9743--9752},
title = {{The impact of abrupt suspension of solar radiation management (termination effect) in experiment G2 of the Geoengineering Model Intercomparison Project (GeoMIP)}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/jgrd.50762 http://doi.wiley.com/10.1002/jgrd.50762},
volume = {118},
year = {2013}
}
@article{Jones2016c,
abstract = {Abstract. Coordinated experimental design and implementation has become a cornerstone of global climate modelling. Model Intercomparison Projects (MIPs) enable systematic and robust analysis of results across many models, by reducing the influence of ad hoc differences in model set-up or experimental boundary conditions. As it enters its 6th phase, the Coupled Model Intercomparison Project (CMIP6) has grown significantly in scope with the design and documentation of individual simulations delegated to individual climate science communities. The Coupled Climate–Carbon Cycle Model Intercomparison Project (C4MIP) takes responsibility for design, documentation, and analysis of carbon cycle feedbacks and interactions in climate simulations. These feedbacks are potentially large and play a leading-order contribution in determining the atmospheric composition in response to human emissions of CO2 and in the setting of emissions targets to stabilize climate or avoid dangerous climate change. For over a decade, C4MIP has coordinated coupled climate–carbon cycle simulations, and in this paper we describe the C4MIP simulations that will be formally part of CMIP6. While the climate–carbon cycle community has created this experimental design, the simulations also fit within the wider CMIP activity, conform to some common standards including documentation and diagnostic requests, and are designed to complement the CMIP core experiments known as the Diagnostic, Evaluation and Characterization of Klima (DECK). C4MIP has three key strands of scientific motivation and the requested simulations are designed to satisfy their needs: (1) pre-industrial and historical simulations (formally part of the common set of CMIP6 experiments) to enable model evaluation, (2) idealized coupled and partially coupled simulations with 1{\%} per year increases in CO2 to enable diagnosis of feedback strength and its components, (3) future scenario simulations to project how the Earth system will respond to anthropogenic activity over the 21st century and beyond. This paper documents in detail these simulations, explains their rationale and planned analysis, and describes how to set up and run the simulations. Particular attention is paid to boundary conditions, input data, and requested output diagnostics. It is important that modelling groups participating in C4MIP adhere as closely as possible to this experimental design.},
author = {Jones, Chris D. and Arora, Vivek and Friedlingstein, Pierre and Bopp, Laurent and Brovkin, Victor and Dunne, John and Graven, Heather and Hoffman, Forrest and Ilyina, Tatiana and John, Jasmin G. and Jung, Martin and Kawamiya, Michio and Koven, Charlie and Pongratz, Julia and Raddatz, Thomas and Randerson, James T. and Zaehle, S{\"{o}}nke},
doi = {10.5194/gmd-9-2853-2016},
isbn = {1991-9603},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {aug},
number = {8},
pages = {2853--2880},
title = {{C4MIP – The Coupled Climate–Carbon Cycle Model Intercomparison Project: experimental protocol for CMIP6}},
type = {Journal Article},
url = {https://www.geosci-model-dev.net/9/2853/2016/},
volume = {9},
year = {2016}
}
@article{Jones2013c,
abstract = {AbstractThe carbon cycle is a crucial Earth system component affecting climate and atmospheric composition. The response of natural carbon uptake to CO2 and climate change will determine anthropogenic emissions compatible with a target CO2 pathway. For phase 5 of the Coupled Model Intercomparison Project (CMIP5), four future representative concentration pathways (RCPs) have been generated by integrated assessment models (IAMs) and used as scenarios by state-of-the-art climate models, enabling quantification of compatible carbon emissions for the four scenarios by complex, process-based models. Here, the authors present results from 15 such Earth system GCMs for future changes in land and ocean carbon storage and the implications for anthropogenic emissions. The results are consistent with the underlying scenarios but show substantial model spread. Uncertainty in land carbon uptake due to differences among models is comparable with the spread across scenarios. Model estimates of historical fossil-fuel emissions agree well with reconstructions, and future projections for representative concentration pathway 2.6 (RCP2.6) and RCP4.5 are consistent with the IAMs. For high-end scenarios (RCP6.0 and RCP8.5), GCMs simulate smaller compatible emissions than the IAMs, indicating a larger climate?carbon cycle feedback in the GCMs in these scenarios. For the RCP2.6 mitigation scenario, an average reduction of 50{\%} in emissions by 2050 from 1990 levels is required but with very large model spread (14{\%}?96{\%}). The models also disagree on both the requirement for sustained negative emissions to achieve the RCP2.6 CO2 concentration and the success of this scenario to restrict global warming below 2°C. All models agree that the future airborne fraction depends strongly on the emissions profile with higher airborne fraction for higher emissions scenarios.},
annote = {doi: 10.1175/JCLI-D-12-00554.1},
author = {Jones, Chris D. and Robertson, Eddy and Arora, Vivek and Friedlingstein, Pierre and Shevliakova, Elena and Bopp, Laurent and Brovkin, Victor and Hajima, Tomohiro and Kato, Etsushi and Kawamiya, Michio and Liddicoat, Spencer and Lindsay, Keith and Reick, Christian H and Roelandt, Caroline and Segschneider, Joachim and Tjiputra, Jerry},
doi = {10.1175/JCLI-D-12-00554.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jul},
number = {13},
pages = {4398--4413},
publisher = {American Meteorological Society},
title = {{Twenty-First-Century Compatible CO2 Emissions and Airborne Fraction Simulated by CMIP5 Earth System Models under Four Representative Concentration Pathways}},
url = {https://doi.org/10.1175/JCLI-D-12-00554.1 http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00554.1},
volume = {26},
year = {2013}
}
@article{Jones2009a,
author = {Jones, Chris D. and Lowe, Jason and Liddicoat, Spencer and Betts, Richard},
doi = {10.1038/ngeo555},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jul},
number = {7},
pages = {484--487},
publisher = {Nature Publishing Group},
title = {{Committed terrestrial ecosystem changes due to climate change}},
url = {http://www.nature.com/articles/ngeo555},
volume = {2},
year = {2009}
}
@article{Jones2020,
author = {Jones, Matthew W and Abatzoglou, John T and Veraverbeke, Sander and Andela, Niels and Lasslop, Gitta and Adam, J P},
file = {::},
title = {{Human activities modulate regional fire trends despite the upwards pressure of global climate change}},
year = {2020}
}
@article{Jones2019,
author = {Jones, Chris D. and Fr{\"{o}}licher, Thomas L. and Koven, Charles and MacDougall, Andrew H. and Matthews, H. Damon and Zickfeld, Kirsten and Rogelj, Joeri and Tokarska, Katarzyna B. and Gillett, Nathan P. and Ilyina, Tatiana and Meinshausen, Malte and Mengis, Nadine and S{\'{e}}f{\'{e}}rian, Roland and Eby, Michael and Burger, Friedrich A.},
doi = {10.5194/gmd-12-4375-2019},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {oct},
number = {10},
pages = {4375--4385},
title = {{The Zero Emissions Commitment Model Intercomparison Project (ZECMIP) contribution to C4MIP: quantifying committed climate changes following zero carbon emissions}},
url = {https://www.geosci-model-dev.net/12/4375/2019/ https://gmd.copernicus.org/articles/12/4375/2019/},
volume = {12},
year = {2019}
}
@article{Jones,
abstract = {To achieve the goals of the Paris Agreement requires deep and rapid reductions in anthropogenic CO2 emissions, but uncertainty surrounds the magnitude and depth of reductions. Earth system models provide a means to quantify the link from emissions to global climate change. Using the concept of TCRE - the transient climate response to cumulative carbon emissions - we can estimate the remaining carbon budget to achieve 1.5 or 2 °C. But the uncertainty is large, and this hinders the usefulness of the concept. Uncertainty in carbon budgets associated with a given global temperature rise is determined by the physical Earth system, and therefore Earth system modelling has a clear and high priority remit to address and reduce this uncertainty. Here we explore multi-model carbon cycle simulations across three generations of Earth system models to quantitatively assess the sources of uncertainty which propagate through to TCRE. Our analysis brings new insights which will allow us to determine how we can better direct our research priorities in order to reduce this uncertainty. We emphasise that uses of carbon budget estimates must bear in mind the uncertainty stemming from the biogeophysical Earth system, and we recommend specific areas where the carbon cycle research community needs to re-focus activity in order to try to reduce this uncertainty. We conclude that we should revise focus from the climate feedback on the carbon cycle to place more emphasis on CO2 as the main driver of carbon sinks and their long-term behaviour. Our proposed framework will enable multiple constraints on components of the carbon cycle to propagate to constraints on remaining carbon budgets.},
author = {Jones, Chris D. and Friedlingstein, Pierre},
doi = {10.1088/1748-9326/ab858a},
issn = {1748-9326},
journal = {Environmental Research Letters},
keywords = {carbon budgets,carbon cycle feedbacks,constraints,research priorities},
month = {jun},
number = {7},
pages = {074019},
publisher = {Institute of Physics Publishing},
title = {{Quantifying process-level uncertainty contributions to TCRE and carbon budgets for meeting Paris Agreement climate targets}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/ab858a https://doi.org/10.1088/1748-9326/ab858a},
volume = {15},
year = {2020}
}
@article{Jones2019b,
abstract = {Large Igneous Provinces (LIPs) are associated with the largest climate perturbations in Earth's history. The North Atlantic Igneous Province (NAIP) and Paleocene-Eocene Thermal Maximum (PETM) constitute an exemplar of this association. As yet we have no means to reconstruct the pacing of LIP greenhouse gas emissions for comparison with climate records at millennial resolution. Here, we calculate carbon-based greenhouse gas fluxes associated with the NAIP at sub-millennial resolution by linking measurements of the mantle convection process that generated NAIP magma with observations of the individual geological structures that controlled gas emissions in a Monte Carlo framework. These simulations predict peak emissions flux of 0.2–0.5 PgC yr–1 and show that the NAIP could have initiated PETM climate change. This is the first predictive model of carbon emissions flux from any proposed PETM carbon source that is directly constrained by observations of the geological structures that controlled the emissions.},
author = {Jones, Stephen M and Hoggett, Murray and Greene, Sarah E and {Dunkley Jones}, Tom},
doi = {10.1038/s41467-019-12957-1},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {5547},
title = {{Large Igneous Province thermogenic greenhouse gas flux could have initiated Paleocene–Eocene Thermal Maximum climate change}},
url = {https://doi.org/10.1038/s41467-019-12957-1},
volume = {10},
year = {2019}
}
@article{doi:10.1029/2000GB001375,
abstract = {A coupled physical-biogeochemical climate model that includes a dynamic global vegetation model and a representation of a coupled atmosphere-ocean general circulation model is driven by the nonintervention emission scenarios recently developed by the Intergovernmental Panel on Climate Change (IPCC). Atmospheric CO2, carbon sinks, radiative forcing by greenhouse gases (GHGs) and aerosols, changes in the fields of surface-air temperature, precipitation, cloud cover, ocean thermal expansion, and vegetation structure are projected. Up to 2100, atmospheric CO2 increases to 540 ppm for the lowest and to 960 ppm for the highest emission scenario analyzed. Sensitivity analyses suggest an uncertainty in these projections of −10 to +30{\%} for a given emission scenario. Radiative forcing is estimated to increase between 3 and 8 W m−2 between now and 2100. Simulated warmer conditions in North America and Eurasia affect ecosystem structure: boreal trees expand poleward in high latitudes and are partly replaced by temperate trees and grasses at lower latitudes. The consequences for terrestrial carbon storage depend on the assumed sensitivity of climate to radiative forcing, the sensitivity of soil respiration to temperature, and the rate of increase in radiative forcing by both CO2 and other GHGs. In the most extreme cases, the terrestrial biosphere becomes a source of carbon during the second half of the century. High GHG emissions and high contributions of non-CO2 agents to radiative forcing favor a transient terrestrial carbon source by enhancing warming and the associated release of soil carbon.},
annote = {added by A.Eliseev 25.01.2019},
author = {Joos, Fortunat and Prentice, I Colin and Sitch, Stephen and Meyer, Robert and Hooss, Georg and Plattner, Gian-Kasper and Gerber, Stefan and Hasselmann, Klaus},
doi = {10.1029/2000GB001375},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {dec},
number = {4},
pages = {891--907},
title = {{Global warming feedbacks on terrestrial carbon uptake under the Intergovernmental Panel on Climate Change (IPCC) emission scenarios}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2000GB001375 http://doi.wiley.com/10.1029/2000GB001375},
volume = {15},
year = {2001}
}
@article{acp-13-2793-2013,
abstract = {Abstract. The responses of carbon dioxide (CO2) and other climate variables to an emission pulse of CO2 into the atmosphere are often used to compute the Global Warming Potential (GWP) and Global Temperature change Potential (GTP), to characterize the response timescales of Earth System models, and to build reduced-form models. In this carbon cycle-climate model intercomparison project, which spans the full model hierarchy, we quantify responses to emission pulses of different magnitudes injected under different conditions. The CO2 response shows the known rapid decline in the first few decades followed by a millennium-scale tail. For a 100 Gt-C emission pulse added to a constant CO2 concentration of 389 ppm, 25 ± 9{\%} is still found in the atmosphere after 1000 yr; the ocean has absorbed 59 ± 12{\%} and the land the remainder (16 ± 14{\%}). The response in global mean surface air temperature is an increase by 0.20 ± 0.12 °C within the first twenty years; thereafter and until year 1000, temperature decreases only slightly, whereas ocean heat content and sea level continue to rise. Our best estimate for the Absolute Global Warming Potential, given by the time-integrated response in CO2 at year 100 multiplied by its radiative efficiency, is 92.5 × 10{\&}minus;15 yr W m−2 per kg-CO2. This value very likely (5 to 95{\%} confidence) lies within the range of (68 to 117) × 10{\&}minus;15 yr W m−2 per kg-CO2. Estimates for time-integrated response in CO2 published in the IPCC First, Second, and Fourth Assessment and our multi-model best estimate all agree within 15{\%} during the first 100 yr. The integrated CO2 response, normalized by the pulse size, is lower for pre-industrial conditions, compared to present day, and lower for smaller pulses than larger pulses. In contrast, the response in temperature, sea level and ocean heat content is less sensitive to these choices. Although, choices in pulse size, background concentration, and model lead to uncertainties, the most important and subjective choice to determine AGWP of CO2 and GWP is the time horizon.},
author = {Joos, F and Roth, R and Fuglestvedt, J S and Peters, G P and Enting, I G and von Bloh, W and Brovkin, V and Burke, E J and Eby, M and Edwards, N R and Friedrich, T and Fr{\"{o}}licher, T L and Halloran, P R and Holden, P B and Jones, C and Kleinen, T and Mackenzie, F T and Matsumoto, K and Meinshausen, M and Plattner, G.-K. and Reisinger, A and Segschneider, J and Shaffer, G and Steinacher, M and Strassmann, K and Tanaka, K and Timmermann, A and Weaver, A J},
doi = {10.5194/acp-13-2793-2013},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {mar},
number = {5},
pages = {2793--2825},
title = {{Carbon dioxide and climate impulse response functions for the computation of greenhouse gas metrics: a multi-model analysis}},
url = {https://www.atmos-chem-phys.net/13/2793/2013/},
volume = {13},
year = {2013}
}
@article{Joos2020,
author = {Joos, Fortunat and Spahni, Renato and Stocker, Benjamin D. and Lienert, Sebastian and M{\"{u}}ller, Jurek and Fischer, Hubertus and Schmitt, Jochen and Prentice, I. Colin and Otto-Bliesner, Bette and Liu, Zhengyu},
doi = {10.5194/bg-17-3511-2020},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jul},
number = {13},
pages = {3511--3543},
title = {{N2O changes from the Last Glacial Maximum to the preindustrial – Part 2: terrestrial N2O emissions and carbon–nitrogen cycle interactions}},
url = {https://bg.copernicus.org/articles/17/3511/2020/},
volume = {17},
year = {2020}
}
@article{Jung2017c,
abstract = {Large interannual variations in the measured growth rate of atmospheric carbon dioxide (CO2) originate primarily from fluctuations in carbon uptake by land ecosystems1,2,3. It remains uncertain, however, to what extent temperature and water availability control the carbon balance of land ecosystems across spatial and temporal scales3,4,5,6,7,8,9,10,11,12,13,14. Here we use empirical models based on eddy covariance data15 and process-based models16,17 to investigate the effect of changes in temperature and water availability on gross primary productivity (GPP), terrestrial ecosystem respiration (TER) and net ecosystem exchange (NEE) at local and global scales. We find that water availability is the dominant driver of the local interannual variability in GPP and TER. To a lesser extent this is true also for NEE at the local scale, but when integrated globally, temporal NEE variability is mostly driven by temperature fluctuations. We suggest that this apparent paradox can be explained by two compensatory water effects. Temporal water-driven GPP and TER variations compensate locally, dampening water-driven NEE variability. Spatial water availability anomalies also compensate, leaving a dominant temperature signal in the year-to-year fluctuations of the land carbon sink. These findings help to reconcile seemingly contradictory reports regarding the importance of temperature and water in controlling the interannual variability of the terrestrial carbon balance3,4,5,6,9,11,12,14. Our study indicates that spatial climate covariation drives the global carbon cycle response.},
author = {Jung, Martin and Reichstein, Markus and Schwalm, Christopher R. and Huntingford, Chris and Sitch, Stephen and Ahlstr{\"{o}}m, Anders and Arneth, Almut and Camps-Valls, Gustau and Ciais, Philippe and Friedlingstein, Pierre and Gans, Fabian and Ichii, Kazuhito and Jain, Atul K. and Kato, Etsushi and Papale, Dario and Poulter, Ben and Raduly, Botond and R{\"{o}}denbeck, Christian and Tramontana, Gianluca and Viovy, Nicolas and Wang, Ying-Ping and Weber, Ulrich and Zaehle, S{\"{o}}nke and Zeng, Ning},
doi = {10.1038/nature20780},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {jan},
number = {7638},
pages = {516--520},
pmid = {15752562685542250875},
publisher = {Nature Publishing Group},
title = {{Compensatory water effects link yearly global land CO2 sink changes to temperature}},
url = {http://www.nature.com/articles/nature20780 http://dx.doi.org/10.1038/nature20780},
volume = {541},
year = {2017}
}
@article{Junium2018,
abstract = {The degree to which ocean deoxygenation will alter the function of marine communities remains unclear but may be best constrained by detailed study of intervals of rapid warming in the geologic past. The Paleocene–Eocene Thermal Maximum (PETM) was an interval of rapid warming that was the result of increasing contents of greenhouse gases in the atmosphere that had wide ranging effects on ecosystems globally. Here, we present stable nitrogen isotope data from the Eastern Peri-Tethys Ocean that record a significant transition in the nitrogen cycle. At the initiation of the PETM, the nitrogen isotopic composition of sediments decreased by {\~{}}6‰ to as low as −3.4‰, signaling reorganization of the marine nitrogen cycle. Warming, changes in ocean circulation, and deoxygenation caused a transition to nitrogen cycle to conditions that were most similar to those experienced during Oceanic Anoxic Events of the Mesozoic.},
author = {Junium, Christopher K. and Dickson, Alexander J. and Uveges, Benjamin T.},
doi = {10.1038/s41467-018-05486-w},
isbn = {4146701805486},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {3186},
title = {{Perturbation to the nitrogen cycle during rapid Early Eocene global warming}},
url = {http://www.nature.com/articles/s41467-018-05486-w},
volume = {9},
year = {2018}
}
@article{Kohler2014,
abstract = {Ice core records show evidence for an abrupt, and thus far unexplained, increase in atmospheric CO2 levels {\~{}}14,600 years ago. Here, the authors combine ice core data, a precisely dated decline in atmospheric 14C and numerical simulations, and propose thawing permafrost as a possible source of this event.},
author = {K{\"{o}}hler, Peter and Knorr, Gregor and Bard, Edouard},
doi = {10.1038/ncomms6520},
issn = {2041-1723},
journal = {Nature Communications},
keywords = {Atmospheric science,Biogeochemistry,Palaeoclimate},
month = {dec},
number = {1},
pages = {5520},
publisher = {Nature Publishing Group},
title = {{Permafrost thawing as a possible source of abrupt carbon release at the onset of the B{\o}lling/Aller{\o}d}},
url = {http://www.nature.com/articles/ncomms6520},
volume = {5},
year = {2014}
}
@article{Kalidindi2015,
author = {Kalidindi, Sirisha and Bala, Govindasamy and Modak, Angshuman and Caldeira, Ken},
doi = {10.1007/s00382-014-2240-3},
issn = {0930-7575},
journal = {Climate Dynamics},
month = {may},
number = {9-10},
pages = {2909--2925},
publisher = {Springer Berlin Heidelberg},
title = {{Modeling of solar radiation management: a comparison of simulations using reduced solar constant and stratospheric sulphate aerosols}},
url = {http://link.springer.com/10.1007/s00382-014-2240-3},
volume = {44},
year = {2015}
}
@article{Kalliokoski2020,
abstract = {The pressure to increase forest and land carbon stocks simultaneously with increasing forest based biomass harvest for energy and materials emphasizes the need for dedicated analyses of impacts and possible trade-offs between these different mitigation options including also forest related biophysical factors, surface albedo and the formation of biogenic Secondary Organic Aerosols (SOA). We analyzed the change in global radiative forcing (RF) due to changes in these climatic agents as affected by the change in state of Finnish forests under increased or decreased harvest scenarios from a baseline. We also included avoided emissions due to wood material and energy substitution. Increasing harvests from baseline (65{\%} of Current Annual Increment) decreased the total carbon sink (carbon in trees, soil and harvested wood products) at least for 50 years. When we coupled this change in carbon with other biosphere responses, surface albedo and aerosols, decreasing harvests from the baseline produced the largest cooling effect during 50 years. Accounting also for the avoided emissions due to increased wood use, the RF responses of the two lowest harvest scenarios were within uncertainty range. Our results show that the effects of forest management on SOA formation should be included in the analyses trying to deduce the net climate impact of forest use. The inclusion of the rarely considered SOA effects enforces the view that the lower the harvest, the more climatic cooling boreal forests provide. These results should act as a caution mark for policy makers who are emphasizing the increased utilization of forest biomass for short-living products and bioenergy as an efficient measure to mitigate climate change.},
author = {Kalliokoski, Tuomo and B{\"{a}}ck, Jaana and Boy, Michael and Kulmala, Markku and Kuusinen, Nea and M{\"{a}}kel{\"{a}}, Annikki and Minkkinen, Kari and Minunno, Francesco and Paasonen, Pauli and Peltoniemi, Mikko and Taipale, Ditte and Valsta, Lauri and Vanhatalo, Anni and Zhou, Luxi and Zhou, Putian and Berninger, Frank},
doi = {10.3389/ffgc.2020.562044},
issn = {2624-893X},
journal = {Frontiers in Forests and Global Change},
pages = {112},
title = {{Mitigation Impact of Different Harvest Scenarios of Finnish Forests That Account for Albedo, Aerosols, and Trade-Offs of Carbon Sequestration and Avoided Emissions}},
volume = {3},
year = {2020}
}
@article{ClaudiaKammannJimIppolitoNikolasHagemannNilsBorchardMariaLuzCayuelaJoseM.EstavilloTeresaFuertes-MendizabalSimonJefferyJurgenKernJeffNovakDanielRasseSannaSaarnioHans-PeterSchmidt2017,
abstract = {Agriculture and land use change has significantly increased atmospheric emissions of the non-CO2 green-house gases (GHG) nitrous oxide (N2O) and methane (CH4). Since human nutritional and bioenergy needs continue to increase, at a shrinking global land area for production, novel land management strategies are required that reduce the GHG footprint per unit of yield. Here we review the potential of biochar to reduce N2O and CH4 emissions from agricultural practices including potential mechanisms behind observed effects. Furthermore, we investigate alternative uses of biochar in agricultural land management that may significantly reduce the GHG-emissions-per-unit-of-product footprint, such as (i) pyrolysis of manures as hygienic alternative to direct soil application, (ii) using biochar as fertilizer carrier matrix for underfoot fertilization, biochar use (iii) as composting additive or (iv) as feed additive in animal husbandry or for manure treatment. We conclude that the largest future research needs lay in conducting life-cycle GHG assessments when using biochar as an on-farm management tool for nutrient-rich biomass waste streams.},
author = {Kammann, Claudia and Ippoloto, Jim and Hagemann, Nikolas and Borchard, Nils and Cayuela, Maria Luz and Estavillo, Jos{\'{e}} M. and Fuertes-Mendizabal, Teresa and Jeffery, Simon and Kern, J{\"{u}}rgen and Novak, Jeff and Rasse, Daniel and Saarnio, Sanna and Schmidt, Hans-Peter and Spokas, Kurt and Wrage-M{\"{o}}nning, N.},
doi = {10.3846/16486897.2017.1319375},
issn = {1648-6897},
journal = {Journal of Environmental Engineering and Landscape Management},
month = {jun},
number = {2},
pages = {114--139},
title = {{Biochar as a Tool to Reduce the Agricultural Greenhouse-gas Burden – Knowns, Unknowns and Future Research Needs}},
url = {http://dx.doi.org/10.3846/16486897.2017.1319375 http://journals.vgtu.lt/index.php/JEELM/article/view/1632},
volume = {25},
year = {2017}
}
@article{Kantola2017,
abstract = { Conventional row crop agriculture for both food and fuel is a source of carbon dioxide (CO2) and nitrous oxide (N2O) to the atmosphere, and intensifying production on agricultural land increases the potential for soil C loss and soil acidification due to fertilizer use. Enhanced weathering (EW) in agricultural soils—applying crushed silicate rock as a soil amendment—is a method for combating global climate change while increasing nutrient availability to plants. EW uses land that is already producing food and fuel to sequester carbon (C), and reduces N2O loss through pH buffering. As biofuel use increases, EW in bioenergy crops offers the opportunity to sequester CO2 while reducing fossil fuel combustion. Uncertainties remain in the long-term effects and global implications of large-scale efforts to directly manipulate Earth's atmospheric CO2 composition, but EW in agricultural lands is an opportunity to employ these soils to sequester atmospheric C while benefitting crop production and the global climate. },
author = {Kantola, Ilsa B and Masters, Michael D and Beerling, David J and Long, Stephen P and DeLucia, Evan H},
doi = {10.1098/rsbl.2016.0714},
journal = {Biology Letters},
number = {4},
pages = {20160714},
title = {{Potential of global croplands and bioenergy crops for climate change mitigation through deployment for enhanced weathering}},
volume = {13},
year = {2017}
}
@article{Karelin2017,
abstract = {Various human footprints on the flux of biogenic greenhouse gases from permafrost-affected soils in Arctic and boreal domains in Russia are considered. Tendencies of significant growth or suppression of soil CO2 fluxes change across types of human impact. Overall, the human impacts increase the mean value and variance of local soil CO2 flux. Human footprint on methane exchange between soil and atmosphere is mediated by drainage. However, all the types of human impact suppress the sources and increase sinks of methane to the land ecosystems. N2O flux grew under the considered types of human impact. Based on the results, we suggest that human footprint on soil greenhouse gases fluxes is comparable to the effect of climate change at an annual to decadal timescales.},
author = {Karelin, D V and Goryachkin, S V and Zamolodchikov, D G and Dolgikh, A V and Zazovskaya, E P and Shishkov, V A and Kraev, G N},
doi = {10.1134/S1028334X17120133},
issn = {1531-8354},
journal = {Doklady Earth Sciences},
number = {2},
pages = {1467--1469},
title = {{Human footprints on greenhouse gas fluxes in cryogenic ecosystems}},
url = {https://doi.org/10.1134/S1028334X17120133},
volume = {477},
year = {2017}
}
@article{Karhu2011,
abstract = {Biochar addition to agricultural soil has been suggested to mitigate climate change through increased biogenic carbon storage and reduction of greenhouse gas emissions. We measured the fluxes of N2O, CO2, and CH4 after adding 9tha−1 biochar on an agricultural soil in Southern Finland in May 2009. We conducted these measurements twice a week for 1.5 months, between sowing and canopy closure, to capture the period of highest N2O emissions, where the potential for mitigation would also be highest. Biochar addition increased CH4 uptake (96{\%} increase in the average cumulative CH4 uptake), but no statistically significant differences were observed in the CO2 and N2O emissions between the biochar amended and control plots. Added biochar increased soil water holding capacity by 11{\%}. Further studies are needed to clarify whether this may help balance fluctuations in water availability to plants in the future climate with more frequent drought periods.},
author = {Karhu, Kristiina and Mattila, Tuomas and Bergstr{\"{o}}m, Irina and Regina, Kristiina},
doi = {https://doi.org/10.1016/j.agee.2010.12.005},
issn = {0167-8809},
journal = {Agriculture, Ecosystems {\&} Environment},
number = {1},
pages = {309--313},
title = {{Biochar addition to agricultural soil increased CH4 uptake and water holding capacity – Results from a short-term pilot field study}},
volume = {140},
year = {2011}
}
@article{Katavouta2018a,
abstract = {The Transient Climate Response to Emissions (TCRE), the ratio of surface warming and cumulative carbon emissions, is controlled by a product of thermal and carbon contributions. The carbon contribution involves the airborne fraction and the ratio of ocean saturated and atmospheric carbon inventories, with this ratio controlled by ocean carbonate chemistry. The evolution of the carbon contribution to the TCRE is illustrated in a hierarchy of models: a box model of the atmosphere-ocean and an Earth system model, both integrated for 1,000 years, and a suite of Earth system models integrated for 140 years. For all models, there is the same generic carbonate chemistry response: An acidifying ocean during emissions leads to a decrease in the ratio of the ocean saturated and atmospheric carbon inventories and the carbon contribution to the TCRE. Hence, ocean carbonate chemistry is important in controlling the magnitude of the TCRE and its evolution in time.},
annote = {From Duplicate 3 (Reconciling atmospheric and oceanic views of the Transient Climate Response to Emissions - Katavouta, Anna; Williams, Richard G.; Goodwin, Philip; Roussenov, Vassil)

From Duplicate 1 (Reconciling Atmospheric and Oceanic Views of the Transient Climate Response to Emissions - Katavouta, Anna; Williams, Richard G; Goodwin, Philip; Roussenov, Vassil)

doi: 10.1029/2018GL077849

From Duplicate 4 (Reconciling atmospheric and oceanic views of the Transient Climate Response to Emissions - Katavouta, Anna; Williams, Richard G; Goodwin, Philip; Roussenov, Vassil)

doi: 10.1029/2018GL077849},
author = {Katavouta, Anna and Williams, Richard G. and Goodwin, Philip and Roussenov, Vassil},
doi = {10.1029/2018GL077849},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {jun},
number = {12},
pages = {6205--6214},
publisher = {Wiley-Blackwell},
title = {{Reconciling Atmospheric and Oceanic Views of the Transient Climate Response to Emissions}},
url = {http://doi.wiley.com/10.1029/2018GL077849 https://doi.org/10.1029/2018GL077849},
volume = {45},
year = {2018}
}
@article{Katavouta2019a,
abstract = {The surface warming response to carbon emissions is affected by how the ocean sequesters excess heat and carbon supplied to the climate system. This ocean uptake involves the ventilation mechanism, where heat and carbon are taken up by the mixed layer and transferred to the thermocline and deep ocean. The effect of ocean ventilation on the surface warming response to carbon emissions is explored using simplified conceptual models of the atmosphere and ocean with and without explicit representation of the meridional overturning. Sensitivity experiments are conducted to investigate the effects of (i) mixed layer thickness, (ii) rate of ventilation of the ocean interior, (iii) strength of the meridional overturning, and (iv) extent of subduction in the Southern Ocean. Our diagnostics focus on a climate metric, the transient climate response to carbon emissions (TCRE), defined by the ratio of surface warming to the cumulative carbon emissions, which may be expressed in terms of separate thermal and carbon contributions. The variability in the thermal contribution due to changes in ocean ventilation dominates the variability in the TCRE on time scales from years to centuries, while that of the carbon contribution dominates on time scales from centuries to millennia. These ventilated controls are primarily from changes in the mixed layer thickness on decadal time scales, and in the rate of ventilated transfer from the mixed layer to the thermocline and deep ocean on centennial and millennial time scales, which is itself affected by the strength of the meridional overturning and extent of subduction in the Southern Ocean.},
author = {Katavouta, Anna and Williams, Richard G. and Goodwin, Philip},
doi = {10.1175/JCLI-D-18-0829.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {aug},
number = {16},
pages = {5085--5105},
title = {{The Effect of Ocean Ventilation on the Transient Climate Response to Emissions}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-18-0829.1},
volume = {32},
year = {2019}
}
@article{Kato2014,
author = {Kato, Etsushi and Yamagata, Yoshiki},
doi = {10.1002/2014EF000249},
issn = {23284277},
journal = {Earth's Future},
language = {en},
month = {sep},
number = {9},
pages = {421--439},
title = {{BECCS capability of dedicated bioenergy crops under a future land-use scenario targeting net negative carbon emissions}},
url = {http://doi.wiley.com/10.1002/2014EF000249},
volume = {2},
year = {2014}
}
@article{Kattge2007,
abstract = {ABSTRACT The Farquhar et?al. model of C3 photosynthesis is frequently used to study the effect of global changes on the biosphere. Its two main parameters representing photosynthetic capacity, Vcmax and Jmax, have been observed to acclimate to plant growth temperature for single species, but a general formulation has never been derived. Here, we present a reanalysis of data from 36 plant species to quantify the temperature dependence of Vcmax and Jmax with a focus on plant growth temperature, i.e. the plants' average ambient temperature during the preceding month. The temperature dependence of Vcmax and Jmax within each data set was described very well by a modified Arrhenius function that accounts for a decrease of Vcmax and Jmax at high temperatures. Three parameters were optimized: base rate, activation energy and entropy term. An effect of plant growth temperature on base rate and activation energy could not be observed, but it significantly affected the entropy term. This caused the optimum temperature of Vcmax and Jmax to increase by 0.44?°C and 0.33?°C per 1?°C increase of growth temperature. While the base rate of Vcmax and Jmax seemed not to be affected, the ratio Jmax?:?Vcmax at 25?°C significantly decreased with increasing growth temperature. This moderate temperature acclimation is sufficient to double-modelled photosynthesis at 40?°C, if plants are grown at 25?°C instead of 17?°C.},
author = {Kattge, Jens and Knorr, Wolfgang},
doi = {10.1111/j.1365-3040.2007.01690.x},
issn = {0140-7791},
journal = {Plant, Cell {\&} Environment},
month = {sep},
number = {9},
pages = {1176--1190},
publisher = {John Wiley {\&} Sons, Ltd (10.1111)},
title = {{Temperature acclimation in a biochemical model of photosynthesis: a reanalysis of data from 36 species}},
volume = {30},
year = {2007}
}
@article{Kaushal201711234,
abstract = {Salinization and alkalinization impact water quality, but these processes have been studied separately, except in arid regions. Globally, salinization has been largely attributed to agriculture, resource extraction, and land clearing. Alkalinization has been attributed to recovery from acidification, with less recognition as an environmental issue. We show that salinization and alkalinization are linked, and trends in these processes impact most of the drainage area of the United States. Increases in salinity and alkalinity are caused by inputs of salts containing strong bases and carbonates that originate from anthropogenic sources and accelerated weathering. We develop a conceptual model unifying our understanding of salinization and alkalinization and its drivers and impacts on fresh water in North America over the past century.Salt pollution and human-accelerated weathering are shifting the chemical composition of major ions in fresh water and increasing salinization and alkalinization across North America. We propose a concept, the freshwater salinization syndrome, which links salinization and alkalinization processes. This syndrome manifests as concurrent trends in specific conductance, pH, alkalinity, and base cations. Although individual trends can vary in strength, changes in salinization and alkalinization have affected 37{\%} and 90{\%}, respectively, of the drainage area of the contiguous United States over the past century. Across 232 United States Geological Survey (USGS) monitoring sites, 66{\%} of stream and river sites showed a statistical increase in pH, which often began decades before acid rain regulations. The syndrome is most prominent in the densely populated eastern and midwestern United States, where salinity and alkalinity have increased most rapidly. The syndrome is caused by salt pollution (e.g., road deicers, irrigation runoff, sewage, potash), accelerated weathering and soil cation exchange, mining and resource extraction, and the presence of easily weathered minerals used in agriculture (lime) and urbanization (concrete). Increasing salts with strong bases and carbonates elevate acid neutralizing capacity and pH, and increasing sodium from salt pollution eventually displaces base cations on soil exchange sites, which further increases pH and alkalinization. Symptoms of the syndrome can include: infrastructure corrosion, contaminant mobilization, and variations in coastal ocean acidification caused by increasingly alkaline river inputs. Unless regulated and managed, the freshwater salinization syndrome can have significant impacts on ecosystem services such as safe drinking water, contaminant retention, and biodiversity.},
author = {Kaushal, Sujay S and Likens, Gene E and Pace, Michael L and Utz, Ryan M and Haq, Shahan and Gorman, Julia and Grese, Melissa},
doi = {10.1073/pnas.1711234115},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {jan},
number = {4},
pages = {E574--E583},
publisher = {National Academy of Sciences},
title = {{Freshwater salinization syndrome on a continental scale}},
url = {http://www.pnas.org/content/early/2018/01/03/1711234115 http://www.pnas.org/lookup/doi/10.1073/pnas.1711234115},
volume = {115},
year = {2018}
}
@article{Kawahata2019a,
author = {Kawahata, Hodaka and Fujita, Kazuhiko and Iguchi, Akira and Inoue, Mayuri and Iwasaki, Shinya and Kuroyanagi, Azumi and Maeda, Ayumi and Manaka, Takuya and Moriya, Kazuyoshi and Takagi, Haruka and Toyofuku, Takashi and Yoshimura, Toshihiro and Suzuki, Atsushi},
doi = {10.1186/s40645-018-0239-9},
issn = {2197-4284},
journal = {Progress in Earth and Planetary Science},
month = {dec},
number = {1},
pages = {5},
title = {{Perspective on the response of marine calcifiers to global warming and ocean acidification – Behavior of corals and foraminifera in a high CO2 world “hot house”}},
url = {https://progearthplanetsci.springeropen.com/articles/10.1186/s40645-018-0239-9},
volume = {6},
year = {2019}
}
@article{Keeling2017a,
abstract = {Climate change and rising CO2 are altering the behavior of land plants in ways that influence how much biomass they produce relative to how much water they need for growth. This study shows that it is possible to detect changes occurring in plants using long-term measurements of the isotopic composition of atmospheric CO2. These measurements imply that plants have globally increased their water use efficiency at the leaf level in proportion to the rise in atmospheric CO2 over the past few decades. While the full implications remain to be explored, the results help to quantify the extent to which the biosphere has become less constrained by water stress globally.A decrease in the 13C/12C ratio of atmospheric CO2 has been documented by direct observations since 1978 and from ice core measurements since the industrial revolution. This decrease, known as the 13C-Suess effect, is driven primarily by the input of fossil fuel-derived CO2 but is also sensitive to land and ocean carbon cycling and uptake. Using updated records, we show that no plausible combination of sources and sinks of CO2 from fossil fuel, land, and oceans can explain the observed 13C-Suess effect unless an increase has occurred in the 13C/12C isotopic discrimination of land photosynthesis. A trend toward greater discrimination under higher CO2 levels is broadly consistent with tree ring studies over the past century, with field and chamber experiments, and with geological records of C3 plants at times of altered atmospheric CO2, but increasing discrimination has not previously been included in studies of long-term atmospheric 13C/12C measurements. We further show that the inferred discrimination increase of 0.014 {\{}$\backslash$textpm{\}} 0.007{\{}$\backslash$textperthousand{\}} ppm-1 is largely explained by photorespiratory and mesophyll effects. This result implies that, at the global scale, land plants have regulated their stomatal conductance so as to allow the CO2 partial pressure within stomatal cavities and their intrinsic water use efficiency to increase in nearly constant proportion to the rise in atmospheric CO2 concentration.},
author = {Keeling, Ralph F and Graven, Heather D and Welp, Lisa R and Resplandy, Laure and Bi, Jian and Piper, Stephen C and Sun, Ying and Bollenbacher, Alane and Meijer, Harro A J},
doi = {10.1073/pnas.1619240114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {sep},
number = {39},
pages = {10361--10366},
publisher = {National Academy of Sciences},
title = {{Atmospheric evidence for a global secular increase in carbon isotopic discrimination of land photosynthesis}},
url = {http://www.pnas.org/content/114/39/10361 http://www.pnas.org/lookup/doi/10.1073/pnas.1619240114},
volume = {114},
year = {2017}
}
@incollection{Keeling2014,
abstract = {A very close coupling exists between changes in atmospheric O2 and CO2 concentrations, owing to the chemistry of photosynthesis, respiration, and combustion. The coupling is not perfect, however, because CO2 variations are partially buffered by reactions involving the inorganic carbon system in seawater, which has no effect on O2. Measurements over the past two decades document variations in O2 on a range of space and time scales, including a long-term decrease driven mostly by fossil fuel burning and seasonal cycles driven by exchanges with the land biosphere and the oceans. In this chapter, these and other features seen in the measurements are described, also discussing variations in the tracer ‘atmospheric potential oxygen,' which is a linear combination of O2 and CO2 designed to be insensitive to exchanges from the land biosphere and thereby sensitive mostly to oceanic processes. Challenges associated with measuring variations in O2 are addressed, and various applications of the observations are discussed, including quantifying the magnitude of the global land and ocean carbon sinks and testing ocean biogeochemical models. An updated budget for global carbon sinks based on O2 measurements from the Scripps O2 program is presented for the decades of the 1990s and 2000s.},
author = {Keeling, R F and Manning, A C},
booktitle = {Treatise on Geochemistry (Second Edition)},
doi = {10.1016/B978-0-08-095975-7.00420-4},
editor = {Holland, Heinrich D and Turekian, Karl K},
isbn = {978-0-08-098300-4},
keywords = {Atmospheric CO,Atmospheric O,Biogeochemical cycles,Carbon cycle,Carbon sinks},
pages = {385--404},
publisher = {Elsevier},
title = {{Studies of Recent Changes in Atmospheric O2 Content}},
url = {http://www.sciencedirect.com/science/article/pii/B9780080959757004204},
year = {2014}
}
@article{Keeling1960b,
author = {Keeling, Charles D.},
doi = {10.1111/j.2153-3490.1960.tb01300.x},
issn = {00402826},
journal = {Tellus},
month = {may},
number = {2},
pages = {200--203},
title = {{The Concentration and Isotopic Abundances of Carbon Dioxide in the Atmosphere}},
volume = {12},
year = {1960}
}
@techreport{Keeling2001b,
address = {San Diego, CA, USA},
author = {Keeling, C. D. and Whorf, T. P. and Wahlen, M. and van der Plicht, J.},
pages = {28},
publisher = {Scripps Institution of Oceanography, University of California San Diego},
series = {SIO Reference No. 01–06},
title = {{Exchanges of Atmospheric CO2 and 13CO2 with the Terrestrial Biosphere and Oceans from 1978 to 2000. I. Global Aspects}},
url = {https://escholarship.org/uc/item/09v319r9},
year = {2001}
}
@article{Keith2015,
abstract = {The risks and benefits of solar geoengineering, or solar radiation management (SRM), depend on assumptions about its implementation. Claims that SRM will reduce precipitation, increase ocean acidification or deplete stratospheric ozone, or that it must be continued forever once started, are not inherent features of SRM; rather, they are features of common scenarios for its implementation. Most analyses assume, for example, that SRM would be used to stop the increase in global temperature or restore temperature to pre-industrial values. We argue that these are poor scenario choices on which to base policy-relevant judgements about SRM. As a basis for further analysis, we provide a scenario that is temporary in that its end point is zero SRM, is moderate in that it offsets only half of the growth in anthropogenic climate forcing and is responsive in that it recognizes that the amount of SRM will be adjusted in light of new information.},
author = {Keith, David W. and MacMartin, Douglas G.},
doi = {10.1038/nclimate2493},
isbn = {1758-6798},
issn = {17586798},
journal = {Nature Climate Change},
number = {3},
pages = {201--206},
title = {{A temporary, moderate and responsive scenario for solar geoengineering}},
volume = {5},
year = {2015}
}
@article{Keith2021,
abstract = {Nature-based solutions (NbS) can address climate change, biodiversity loss, human well-being and their interactions in an integrated way. A major barrier to achieving this is the lack of comprehensiveness in current carbon accounting which has focused on flows rather than stocks of carbon and led to perverse outcomes. We propose a new comprehensive approach to carbon accounting based on the whole carbon cycle, covering both stocks and flows, and linking changes due to human activities with responses in the biosphere and atmosphere. We identify enhancements to accounting, namely; inclusion of all carbon reservoirs, changes in their condition and stability, disaggregated flows, and coverage of all land areas. This comprehensive approach recognises that both carbon stocks (as storage) and carbon flows (as sequestration) contribute to the ecosystem service of global climate regulation. In contrast, current ecosystem services measurement and accounting commonly use only carbon sequestration measured as net flows, while greenhouse gas inventories use flows from sources to sinks. This flow-based accounting has incentivised planting and maintaining young forests with high carbon uptake rates, resulting, perversely, in failing to reveal the greater mitigation benefit from protecting larger, more stable and resilient carbon stocks in natural forests. We demonstrate the benefits of carbon storage and sequestration for climate mitigation, in theory as ecosystem services within an ecosystem accounting framework, and in practice using field data that reveals differences in results between accounting for stocks or flows. Our proposed holistic and comprehensive carbon accounting makes transparent the benefits, trade-offs and shortcomings of NbS actions for climate mitigation and sustainability outcomes. Adopting this approach is imperative for revision of ecosystem accounting systems under the System of Environmental-Economic Accounting and contributing to evidence-based decision-making for international conventions on climate (UNFCCC), biodiversity (CBD) and sustainability (SDGs).},
author = {Keith, Heather and Vardon, Michael and Obst, Carl and Young, Virginia and Houghton, Richard A. and Mackey, Brendan},
doi = {10.1016/j.scitotenv.2020.144341},
issn = {18791026},
journal = {Science of the Total Environment},
pages = {144341},
publisher = {Elsevier B.V.},
title = {{Evaluating nature-based solutions for climate mitigation and conservation requires comprehensive carbon accounting}},
volume = {769},
year = {2021}
}
@article{Kell2011,
abstract = {AbstractBackground. The soil represents a reservoir that contains at least twice as much carbon as does the atmosphere, yet (apart from ‘root crops') mainly ju},
author = {Kell, Douglas B.},
doi = {10.1093/aob/mcr175},
issn = {0305-7364},
journal = {Annals of Botany},
language = {en},
month = {sep},
number = {3},
pages = {407--418},
title = {{Breeding crop plants with deep roots: their role in sustainable carbon, nutrient and water sequestration}},
url = {https://academic.oup.com/aob/article-lookup/doi/10.1093/aob/mcr175},
volume = {108},
year = {2011}
}
@article{Keller2014a,
abstract = {The realization that mitigation efforts to reduce carbon dioxide emissions have, until now, been relatively ineffective has led to an increasing interest in climate engineering as a possible means of preventing the potentially catastrophic consequences of climate change. While many studies have addressed the potential effectiveness of individual methods there have been few attempts to compare them. Here we use an Earth system model to compare the effectiveness and side effects of afforestation, artificial ocean upwelling, ocean iron fertilization, ocean alkalinization and solar radiation management during a high carbon dioxide-emission scenario. We find that even when applied continuously and at scales as large as currently deemed possible, all methods are, individually, either relatively ineffective with limited ({\textless}8{\%}) warming reductions, or they have potentially severe side effects and cannot be stopped without causing rapid climate change. Our simulations suggest that the potential for these types of climate engineering to make up for failed mitigation may be very limited.},
author = {Keller, David P. and Feng, Ellias Y. and Oschlies, Andreas},
doi = {10.1038/ncomms4304},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {3304},
pmid = {24569320},
publisher = {Nature Publishing Group},
title = {{Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario}},
url = {http://www.nature.com/articles/ncomms4304},
volume = {5},
year = {2014}
}
@article{RN637,
abstract = {Abstract. The recent IPCC reports state that continued anthropogenic greenhouse gas emissions are changing the climate, threatening severe, pervasive and irreversible impacts. Slow progress in emissions reduction to mitigate climate change is resulting in increased attention to what is called geoengineering, climate engineering, or climate intervention – deliberate interventions to counter climate change that seek to either modify the Earth's radiation budget or remove greenhouse gases such as CO2 from the atmosphere. When focused on CO2, the latter of these categories is called carbon dioxide removal (CDR). Future emission scenarios that stay well below 2 °C, and all emission scenarios that do not exceed 1.5 °C warming by the year 2100, require some form of CDR. At present, there is little consensus on the climate impacts and atmospheric CO2 reduction efficacy of the different types of proposed CDR. To address this need, the Carbon Dioxide Removal Model Intercomparison Project (or CDRMIP) was initiated. This project brings together models of the Earth system in a common framework to explore the potential, impacts, and challenges of CDR. Here, we describe the first set of CDRMIP experiments, which are formally part of the 6th Coupled Model Intercomparison Project (CMIP6). These experiments are designed to address questions concerning CDR-induced climate reversibility, the response of the Earth system to direct atmospheric CO2 removal (direct air capture and storage), and the CDR potential and impacts of afforestation and reforestation, as well as ocean alkalinization.{\textgreater}},
author = {Keller, David P and Lenton, Andrew and Scott, Vivian and Vaughan, Naomi E and Bauer, Nico and Ji, Duoying and Jones, Chris D and Kravitz, Ben and Muri, Helene and Zickfeld, Kirsten},
doi = {10.5194/gmd-11-1133-2018},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {mar},
number = {3},
pages = {1133--1160},
title = {{The Carbon Dioxide Removal Model Intercomparison Project (CDRMIP): rationale and experimental protocol for CMIP6}},
type = {Journal Article},
url = {https://www.geosci-model-dev.net/11/1133/2018/},
volume = {11},
year = {2018}
}
@incollection{Keller2019,
address = {Boca Raton, FL, USA},
author = {Keller, J.K.},
booktitle = {A Blue Carbon Primer: The State of Coastal Wetland Carbon Science, Practice and Policy},
doi = {10.1201/9780429435362},
editor = {Windham-Myers, L. and Crooks, S. and Troxler},
pages = {93--106},
publisher = {CRC Press},
title = {{Greenhouse gases}},
year = {2018}
}
@article{Keller2018,
abstract = {Increasing atmospheric CO2 is having detrimental effects on the Earth system. Societies have recognized that anthropogenic CO2 release must be rapidly reduced to avoid potentially catastrophic impacts. Achieving this via emissions reductions alone will be very difficult. Carbon dioxide removal (CDR) has been suggested to complement and compensate for insufficient emissions reductions, through increasing natural carbon sinks, engineering new carbon sinks, or combining natural uptake with engineered storage. Here, we review the carbon cycle responses to different CDR approaches and highlight the often-overlooked interaction and feedbacks between carbon reservoirs that ultimately determines CDR efficacy. We also identify future research that will be needed if CDR is to play a role in climate change mitigation, these include coordinated studies to better understand (i) the underlying mechanisms of each method, (ii) how they could be explicitly simulated, (iii) how reversible changes in the climate and carbon cycle are, and (iv) how to evaluate and monitor CDR.},
author = {Keller, David P. and Lenton, Andrew and Littleton, Emma W. and Oschlies, Andreas and Scott, Vivian and Vaughan, Naomi E.},
doi = {10.1007/s40641-018-0104-3},
issn = {2198-6061},
journal = {Current Climate Change Reports},
keywords = {Carbon cycle,Carbon cycle feedbacks,Carbon dioxide removal (CDR),Climate change,Climate feedbacks,Mitigation,Negative emissions},
month = {sep},
number = {3},
pages = {250--265},
publisher = {Current Climate Change Reports},
title = {{The Effects of Carbon Dioxide Removal on the Carbon Cycle}},
url = {http://link.springer.com/10.1007/s40641-018-0104-3},
volume = {4},
year = {2018}
}
@incollection{Keller2019a,
address = {Cham, Switzerland},
author = {Keller, David P.},
booktitle = {Handbook on Marine Environment Protection: Science, Impacts and Sustainable Management},
doi = {10.1007/978-3-319-60156-4_13},
editor = {Salomon, M. and Markus, T.},
isbn = {978-3- 319-60154-0},
pages = {261--276},
publisher = {Springer},
title = {{Marine climate engineering}},
year = {2019}
}
@article{Kelly2016a,
abstract = {? Models of tree responses to climate typically project that elevated atmospheric CO2 con- centration (eCa) will reduce drought impacts on forests. We tested one of the mechanisms underlying this interaction, the ‘low Ci effect', in which stomatal closure in drought conditions reduces the intercellular CO2 concentration (Ci), resulting in a larger relative enhancement of photosynthesis with eCa, and, consequently, a larger relative biomass response. ? We grew two Eucalyptus species of contrasting drought tolerance at ambient and elevated Ca for 6–9 months in large pots maintained at 50{\%} (drought) and 100{\%} field capacity. ? Droughted plants did not have significantly lower Ci than well-watered plants, which we attributed to long-term changes in leaf area. Hence, there should not have been an interaction between eCa and water availability on biomass, and we did not detect one. The xeric species did have higher Ci than the mesic species, indicating lower water-use efficiency, but both species exhibited similar responses of photosynthesis and biomass to eCa, owing to compen- satory differences in the photosynthetic response to Ci. ? Our results demonstrate that long-term acclimation to drought, and coordination among species traits may be important for predicting plant responses to eCa under low water avail- ability.},
author = {Kelly, Jeff W. G. and Duursma, Remko A. and Atwell, Brian J. and Tissue, David T. and Medlyn, Belinda E.},
doi = {10.1111/nph.13715},
isbn = {1469-8137 (Electronic) 0028-646X (Linking)},
issn = {0028646X},
journal = {New Phytologist},
month = {mar},
number = {4},
pages = {1600--1612},
pmid = {26526873},
title = {{Drought × CO2 interactions in trees: a test of the low-intercellular CO2 concentration (Ci) mechanism}},
url = {http://doi.wiley.com/10.1111/nph.13715},
volume = {209},
year = {2016}
}
@article{Kemp2015,
author = {Kemp, David B. and Eichenseer, Kilian and Kiessling, Wolfgang},
doi = {10.1038/ncomms9890},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {8890},
title = {{Maximum rates of climate change are systematically underestimated in the geological record}},
url = {http://www.nature.com/articles/ncomms9890},
volume = {6},
year = {2015}
}
@incollection{Kennedy2019b,
address = {Boca Raton, FL, USA},
author = {Kennedy, H. and Fourqueran, J. and Papadimitriou, S.},
booktitle = {A Blue Carbon Primer: The State of Coastal Wetland Carbon Science, Practice and Policy},
doi = {10.1201/9780429435362},
editor = {Windham-Myers, L. and Crooks, S. and Troxler, T.},
isbn = {9780429435362},
pages = {107--119},
publisher = {CRC Press},
title = {{The calcium carbonate cycle in seagrass ecosystems}},
year = {2018}
}
@article{Keppler2019,
abstract = {The Southern Ocean south of 35°S accounts for approximately half of the annual oceanic carbon uptake, thereby substantially mitigating the effects of anthropogenic carbon dioxide (CO 2 ) emissions. The intensity of this important carbon sink varies considerably on inter-annual to decadal timescales. However, the drivers of this variability are still debated, challenging our ability to accurately predict the future role of the Southern Ocean in absorbing atmospheric carbon. Analysing mapped sea-air CO 2 fluxes, estimated from upscaled surface ocean CO 2 measurements, we find that the overall Southern Ocean carbon sink has weakened since {\~{}}2011, reversing the trend of the reinvigoration period of the 2000s. Although we find significant regional positive and negative responses of the Southern Ocean carbon uptake to changes in the Southern Annular Mode (SAM) over the past 35 years, the net effect of the SAM on the Southern Ocean carbon sink variability is approximately zero, due to the opposing effects of enhanced outgassing in upwelling regions and enhanced carbon uptake elsewhere. Instead, regional shifts in sea level pressure, linked to zonal wavenumber 3 (ZW3) and related changes in surface winds substantially contribute to the inter-annual to decadal variability of the Southern Ocean carbon sink.},
author = {Keppler, Lydia and Landsch{\"{u}}tzer, Peter},
doi = {10.1038/s41598-019-43826-y},
issn = {2045-2322},
journal = {Scientific Reports},
keywords = {Marine chemistry,Physical oceanography},
month = {dec},
number = {1},
pages = {7384},
pmid = {31089173},
publisher = {Nature Publishing Group},
title = {{Regional Wind Variability Modulates the Southern Ocean Carbon Sink}},
url = {www.nature.com/scientificreports http://www.nature.com/articles/s41598-019-43826-y},
volume = {9},
year = {2019}
}
@article{Keppler2020,
abstract = {The seasonal cycle represents one of the largest signals of dissolved inorganic carbon (DIC) in the ocean, yet these seasonal variations are not well established at a global scale. Here, we present the Mapped Observation-Based Oceanic DIC (MOBO-DIC) product, a monthly DIC climatology developed based on the DIC measurements from GLODAPv2.2019 and a two-step neural network method to interpolate and map the measurements. MOBO-DIC extends from the surface down to 2,000 m and from 65°N to 65°S. We find the largest seasonal amplitudes of surface DIC in the northern high-latitude Pacific (∼30 to {\textgreater}50 $\mu$mol kg−1). Surface DIC maxima occur in hemispheric spring and minima in fall, driven by the input of DIC into the upper ocean by mixing during winter, and net community production (NCP) driven drawdown of DIC over summer. The seasonal pattern seen at the surface extends to a nodal depth of {\textless}50 m in the tropics and several hundred meters in the subtropics. Below the nodal depth, the seasonal cycle of DIC has the opposite phase, primarily owing to the seasonal accumulation of DIC stemming from the remineralization of sinking organic matter. The well-captured seasonal drawdown of DIC in the mid-latitudes (23° to 65°) allows us to estimate the spring-to-fall NCP in this region. We find a spatially relatively uniform spring-to-fall NCP of 1.9 ± 1.3 mol C m−2 yr−1, which sums to 3.9 ± 2.7 Pg C yr−1 over this region. This corresponds to a global spring-to-fall NCP of 8.2 ± 5.6 Pg C yr−1.},
author = {Keppler, L. and Landsch{\"{u}}tzer, P. and Gruber, N. and Lauvset, S. K. and Stemmler, I.},
doi = {10.1029/2020GB006571},
issn = {19449224},
journal = {Global Biogeochemical Cycles},
keywords = {DIC,NCP,SOM-FFN,monthly climatology,neural networks,seasonal variability},
number = {12},
pages = {e2020GB006571},
title = {{Seasonal Carbon Dynamics in the Near-Global Ocean}},
volume = {34},
year = {2020}
}
@article{Khatiwala2019,
abstract = {The prevailing hypothesis for lower atmospheric carbon dioxide (CO 2 ) concentrations during glacial periods is an increased efficiency of the ocean's biological pump. However, tests of this and other hypotheses have been hampered by the difficulty to accurately quantify ocean carbon components. Here, we use an observationally constrained earth system model to precisely quantify these components and the role that different processes play in simulated glacial-interglacial CO 2 variations. We find that air-sea disequilibrium greatly amplifies the effects of cooler temperatures and iron fertilization on glacial ocean carbon storage even as the efficiency of the soft-tissue biological pump decreases. These two processes, which have previously been regarded as minor, explain most of our simulated glacial CO 2 drawdown, while ocean circulation and sea ice extent, hitherto considered dominant, emerge as relatively small contributors.},
author = {Khatiwala, S. and Schmittner, A. and Muglia, J.},
doi = {10.1126/sciadv.aaw4981},
issn = {2375-2548},
journal = {Science Advances},
month = {jun},
number = {6},
pages = {eaaw4981},
title = {{Air–sea disequilibrium enhances ocean carbon storage during glacial periods}},
url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aaw4981},
volume = {5},
year = {2019}
}
@article{Kicklighter_2014,
abstract = {Climate change will alter ecosystem metabolism and may lead to a redistribution of vegetation and changes in fire regimes in Northern Eurasia over the 21st century. Land management decisions will interact with these climate-driven changes to reshape the region's landscape. Here we present an assessment of the potential consequences of climate change on land use and associated land carbon sink activity for Northern Eurasia in the context of climate-induced vegetation shifts. Under a ‘business-as-usual' scenario, climate-induced vegetation shifts allow expansion of areas devoted to food crop production (15{\%}) and pastures (39{\%}) over the 21st century. Under a climate stabilization scenario, climate-induced vegetation shifts permit expansion of areas devoted to cellulosic biofuel production (25{\%}) and pastures (21{\%}), but reduce the expansion of areas devoted to food crop production by 10{\%}. In both climate scenarios, vegetation shifts further reduce the areas devoted to timber production by 6–8{\%} over this same time period. Fire associated with climate-induced vegetation shifts causes the region to become more of a carbon source than if no vegetation shifts occur. Consideration of the interactions between climate-induced vegetation shifts and human activities through a modeling framework has provided clues to how humans may be able to adapt to a changing world and identified the trade-offs, including unintended consequences, associated with proposed climate/energy policies.},
author = {Kicklighter, D W and Cai, Y and Zhuang, Q and Parfenova, E I and Paltsev, S and Sokolov, A P and Melillo, J M and Reilly, J M and Tchebakova, N M and Lu, X},
doi = {10.1088/1748-9326/9/3/035004},
journal = {Environmental Research Letters},
month = {mar},
number = {3},
pages = {35004},
publisher = {{\{}IOP{\}} Publishing},
title = {{Potential influence of climate-induced vegetation shifts on future land use and associated land carbon fluxes in Northern Eurasia}},
url = {https://doi.org/10.1088{\%}2F1748-9326{\%}2F9{\%}2F3{\%}2F035004},
volume = {9},
year = {2014}
}
@article{Kirschke2013,
abstract = {Methane is an important greenhouse gas, responsible for about 20{\%} of the warming induced by long-lived greenhouse gases since pre-industrial times. By reacting with hydroxyl radicals, methane reduces the oxidizing capacity of the atmosphere and generates ozone in the troposphere. Although most sources and sinks of methane have been identified, their relative contributions to atmospheric methane levels are highly uncertain. As such, the factors responsible for the observed stabilization of atmospheric methane levels in the early 2000s, and the renewed rise after 2006, remain unclear. Here, we construct decadal budgets for methane sources and sinks between 1980 and 2010, using a combination of atmospheric measurements and results from chemical transport models, ecosystem models, climate chemistry models and inventories of anthropogenic emissions. The resultant budgets suggest that data-driven approaches and ecosystem models overestimate total natural emissions. We build three contrasting emission scenarios — which differ in fossil fuel and microbial emissions — to explain the decadal variability in atmospheric methane levels detected, here and in previous studies, since 1985. Although uncertainties in emission trends do not allow definitive conclusions to be drawn, we show that the observed stabilization of methane levels between 1999 and 2006 can potentially be explained by decreasing-to-stable fossil fuel emissions, combined with stable-to-increasing microbial emissions. We show that a rise in natural wetland emissions and fossil fuel emissions probably accounts for the renewed increase in global methane levels after 2006, although the relative contribution of these two sources remains uncertain.},
author = {Kirschke, Stefanie and Bousquet, Philippe and Ciais, Philippe and Saunois, Marielle and Canadell, Josep G and Dlugokencky, Edward J and Bergamaschi, Peter and Bergmann, Daniel and Blake, Donald R and Bruhwiler, Lori and Cameron-Smith, Philip and Castaldi, Simona and Chevallier, Fr{\'{e}}d{\'{e}}ric and Feng, Liang and Fraser, Annemarie and Heimann, Martin and Hodson, Elke L and Houweling, Sander and Josse, B{\'{e}}atrice and Fraser, Paul J and Krummel, Paul B and Lamarque, Jean-Fran{\c{c}}ois and Langenfelds, Ray L and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Naik, Vaishali and O'Doherty, Simon and Palmer, Paul I and Pison, Isabelle and Plummer, David and Poulter, Benjamin and Prinn, Ronald G and Rigby, Matt and Ringeval, Bruno and Santini, Monia and Schmidt, Martina and Shindell, Drew T and Simpson, Isobel J and Spahni, Renato and Steele, L Paul and Strode, Sarah A and Sudo, Kengo and Szopa, Sophie and van der Werf, Guido R and Voulgarakis, Apostolos and van Weele, Michiel and Weiss, Ray F and Williams, Jason E and Zeng, Guang},
doi = {10.1038/ngeo1955},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {oct},
number = {10},
pages = {813--823},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Three decades of global methane sources and sinks}},
url = {http://dx.doi.org/10.1038/ngeo1955 http://www.nature.com/articles/ngeo1955},
volume = {6},
year = {2013}
}
@article{Turner2018,
abstract = {One contribution of 11 to a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'. The Paleocene-Eocene Thermal Maximum (PETM, approx. 56 Ma) provides a test case for investigating how the Earth system responds to rapid greenhouse gas-driven warming. However, current rates of carbon emissions are approximately 10 Pg C yr −1 , whereas those proposed for the PETM span orders of magnitude-from 1 Pg C yr −1 to greater than the anthropogenic rate. Emissions rate estimates for the PETM are hampered by uncertainty over the total mass of PETM carbon released as well as the PETM onset duration. Here, I review constraints on the onset duration of the carbon isotope excursion (CIE) that is characteristic of the event with a focus on carbon cycle model-based attempts that forgo the need for a traditional sedimentary age model. I also review and compare existing PETM carbon input scenarios employing the Earth system model cGENIE and suggest another possibility-that abrupt input of an isotopically depleted carbon source combined with elevated volcanic outgassing over a longer interval can together account for key features of the PETM CIE. This article is part of a discussion meeting issue 'Hyperthermals: rapid and extreme global warming in our geological past'.},
author = {{Kirtland Turner}, Sandra},
doi = {10.1098/rsta.2017.0082},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
keywords = {Subject Areas: biogeochemistry,carbon emissions,climatology,earth system modelling,geochemistry Keywords: Paleocene-Eocene Thermal Ma},
month = {oct},
number = {2130},
pages = {20170082},
title = {{Constraints on the onset duration of the Paleocene–Eocene Thermal Maximum}},
url = {http://dx. http://rsta.royalsocietypublishing.org/lookup/doi/10.1098/rsta.2017.0082},
volume = {376},
year = {2018}
}
@article{KirtlandTurner2017,
abstract = {Knowledge of the onset duration of the Paleocene-Eocene Thermal Maximum - the largest known greenhouse-gas-driven global warming event of the Cenozoic - is central to drawing inferences for future climate change. Single-foraminifera measurements of the associated carbon isotope excursion from Maud Rise (South Atlantic Ocean) are controversial, as they seem to indicate geologically instantaneous carbon release and anomalously long ocean mixing. Here, we fundamentally reinterpret this record and extract the likely PETM onset duration. First, we employ an Earth system model to illustrate how the response of ocean circulation to warming does not support the interpretation of instantaneous carbon release. Instead, we use a novel sediment-mixing model to show how changes in the relative population sizes of calcareous plankton, combined with sediment mixing, can explain the observations. Furthermore, for any plausible PETM onset duration and sampling methodology, we place a probability on not sampling an intermediate, syn-excursion isotopic value. Assuming mixed-layer carbonate production continued at Maud Rise, we deduce the PETM onset was likely {\textless}5 kyr.},
author = {{Kirtland Turner}, Sandra and Hull, Pincelli M. and Kump, Lee R. and Ridgwell, Andy},
doi = {10.1038/s41467-017-00292-2},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {353},
pmid = {28842564},
publisher = {Springer US},
title = {{A probabilistic assessment of the rapidity of PETM onset}},
url = {http://dx.doi.org/10.1038/s41467-017-00292-2 http://www.nature.com/articles/s41467-017-00292-2},
volume = {8},
year = {2017}
}
@article{rs10050677,
abstract = {Formation of gas emission craters (GEC) is a new process in the permafrost zone, leading to considerable terrain changes. Yet their role in changing the relief is local, incomparable in the volume of the removed deposits to other destructive cryogenic processes. However, the relief-forming role of GECs is not limited to the appearance of the crater itself, but also results in positive and negative microforms as well. Negative microforms are rounded hollows, surrounded by piles of ejected or extruded deposits. Hypotheses related to the origin of these forms are put forward and supported by an analysis of multi-temporal satellite images, field observations and photographs of GECs. Remote sensing data specifically was used for interpretation of landform origin, measuring distances and density of material scattering, identifying scattered material through analysis of repeated imagery. Remote-sensing and field data reliably substantiate an impact nature of the hollows around GECs. It is found that scattering of frozen blocks at a distance of up to 293 m from a GEC is capable of creating an impact hollow. These data indicate the influence of GEC on the relief through the formation of a microrelief within a radius of 15{\&}ndash;20 times the radius of the crater itself. Our study aims at the prediction of risk zones.},
annote = {added by A.Eliseev 25.01.2019},
author = {Kizyakov, Alexander and Khomutov, Artem and Zimin, Mikhail and Khairullin, Rustam and Babkina, Elena and Dvornikov, Yury and Leibman, Marina},
doi = {10.3390/rs10050677},
issn = {2072-4292},
journal = {Remote Sensing},
month = {apr},
number = {5},
pages = {677},
title = {{Microrelief associated with gas emission craters: remote-sensing and field-based study}},
url = {http://www.mdpi.com/2072-4292/10/5/677},
volume = {10},
year = {2018}
}
@article{rs9101023,
abstract = {Gas Emission Craters (GEC) represent a new phenomenon in permafrost regions discovered in the north of West Siberia. In this study we use very-high-resolution Worldview satellite stereopairs and Resurs-P images to reveal and measure the geomorphic features that preceded and followed GEC formation on the Yamal and Gydan peninsulas. Analysis of DEMs allowed us to: (1) distinguish different terrain positions of the GEC, at the foot of a gentle slope (Yamal), and on an upper edge of a terrace slope; (2) notice that the formation of both Yamal and Gydan GECs were preceded by mound development; (3) measure a funnel-shaped upper part and a cylindrical lower part for each crater; (4) and measure the expansion and plan form modification of GECs. Although the general characteristics of both craters are similar, there are differences when comparing both key sites in detail. The height of the mound and diameter of the resulting GEC in Yamal exceeds that in Gydan; GEC-1 was surrounded by a well-developed parapet, while AntGEC did not show any considerable accumulative body. Thus, using very-high-resolution remote sensing data allowed us to discriminate geomorphic features and relief positions characteristic for GEC formation. GECs are a potential threat to commercial facilities in permafrost and indigenous settlements, especially because at present there is no statistically significant number of study objects to identify the local environmental conditions in which the formation of new GEC is possible.},
annote = {added by A.Eliseev 25.01.2019},
author = {Kizyakov, Alexander and Zimin, Mikhail and Sonyushkin, Anton and Dvornikov, Yury and Khomutov, Artem and Leibman, Marina},
doi = {10.3390/rs9101023},
issn = {2072-4292},
journal = {Remote Sensing},
month = {oct},
number = {10},
pages = {1023},
title = {{Comparison of gas emission crater geomorphodynamics on Yamal and Gydan Peninsulas (Russia), based on repeat very-high-resolution stereopairs}},
url = {http://www.mdpi.com/2072-4292/9/10/1023},
volume = {9},
year = {2017}
}
@article{Kleber2007,
abstract = {In this paper, we propose a structure for organo-mineral associations in soils based on recent insights concerning the molecular structure of soil organic matter (SOM), and on extensive published evidence from empirical studies of organo-mineral interfaces. Our conceptual model assumes that SOM consists of a heterogeneous mixture of compounds that display a range of amphiphilic or surfactant-like properties, and are capable of self-organization in aqueous solution. An extension of this self-organizational behavior in solution, we suggest that SOM sorbs to mineral surfaces in a discrete zonal sequence. In the contact zone, the formation of particularly strong organo-mineral associations appears to be favored by situations where either (i) polar organic functional groups of amphiphiles interact via ligand exchange with singly coordinated mineral hydroxyls, forming stable inner-sphere complexes, or (ii) proteinaceous materials unfold upon adsorption, thus increasing adhesive strength by adding hydrophobic interactions to electrostatic binding. Entropic considerations dictate that exposed hydrophobic portions of amphiphilic molecules adsorbed directly to mineral surfaces be shielded from the polar aqueous phase through association with hydrophobic moieties of other amphiphilic molecules. This process can create a membrane-like bilayer containing a hydrophobic zone, whose components may exchange more easily with the surrounding soil solution than those in the contact zone, but which are still retained with considerable force. Sorbed to the hydrophilic exterior of hemimicellar coatings, or to adsorbed proteins, are organic molecules forming an outer region, or kinetic zone, that is loosely retained by cation bridging, hydrogen bonding, and other interactions. Organic material in the kinetic zone may experience high exchange rates with the surrounding soil solution, leading to short residence times for individual molecular fragments. The thickness of this outer region would depend more on input than on the availability of binding sites, and would largely be controlled by exchange kinetics. Movement of organics into and out of this outer region can thus be viewed as similar to a phase-partitioning process. The zonal concept of organo-mineral interactions presented here offers a new basis for understanding and predicting the retention of organic compounds, including contaminants, in soils and sediments.},
author = {Kleber, M and Sollins, P and Sutton, R},
doi = {10.1007/s10533-007-9103-5},
issn = {1573-515X},
journal = {Biogeochemistry},
number = {1},
pages = {9--24},
title = {{A conceptual model of organo-mineral interactions in soils: self-assembly of organic molecular fragments into zonal structures on mineral surfaces}},
url = {https://doi.org/10.1007/s10533-007-9103-5},
volume = {85},
year = {2007}
}
@article{Goldewijk2017,
abstract = {Abstract. This paper presents an update and extension of HYDE, the History Database of the Global Environment (HYDE version 3.2). HYDE is an internally consistent combination of historical population estimates and allocation algorithms with time-dependent weighting maps for land use. Categories include cropland, with new distinctions for irrigated and rain-fed crops (other than rice) and irrigated and rain-fed rice. Grazing lands are also provided, divided into more intensively used pasture and less intensively used rangeland, and further specified with respect to conversion of natural vegetation to facilitate global change modellers. Population is represented by maps of total, urban, rural population, population density and built-up area. The period covered is 10 000 before Common Era (BCE) to 2015 Common Era (CE). All data can be downloaded from https://doi.org/10.17026/dans-25g-gez3. We estimate that global population increased from 4.4 million people (we also estimate a lower range},
author = {{Klein Goldewijk}, Kees and Beusen, Arthur and Doelman, Jonathan and Stehfest, Elke},
doi = {10.5194/essd-9-927-2017},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {dec},
number = {2},
pages = {927--953},
title = {{Anthropogenic land use estimates for the Holocene – HYDE 3.2}},
url = {https://essd.copernicus.org/articles/9/927/2017/},
volume = {9},
year = {2017}
}
@article{Kleinen2018,
author = {Kleinen, Thomas and Brovkin, Victor},
doi = {10.1088/1748-9326/aad824},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {aug},
number = {9},
pages = {094001},
publisher = {{\{}IOP{\}} Publishing},
title = {{Pathway-dependent fate of permafrost region carbon}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/aad824},
volume = {13},
year = {2018}
}
@article{Kleinen2020,
abstract = {We investigate the changes in terrestrial natural methane emissions between the Last Glacial Maximum (LGM) and preindustrial (PI) periods by performing timeslice experiments with a methane-enabled version of MPIESM, the Max Planck Institute Earth System Model. We consider all natural sources of methane except for emissions from wild animals and geological sources, i.e. emissions from wetlands, fires, and termites. Changes are dominated by changes in tropical wetland emissions, with midto-high-latitude wetlands playing a secondary role, and all other natural sources being of minor importance. The emissions are determined by the interplay of vegetation productivity, a function of CO2 and temperature; source area size, affected by sea level and ice sheet extent; and the state of the West African monsoon, with increased emissions from northern Africa during strong monsoon phases. We show that it is possible to explain the difference in atmospheric methane between LGM and PI purely by changes in emissions. As emissions more than double between LGM and PI, changes in the atmospheric lifetime of CH4, as proposed in other studies, are not required.},
author = {Kleinen, Thomas and Mikolajewicz, Uwe and Brovkin, Victor},
doi = {10.5194/cp-16-575-2020},
issn = {18149332},
journal = {Climate of the Past},
number = {2},
pages = {575--595},
title = {{Terrestrial methane emissions from the Last Glacial Maximum to the preindustrial period}},
volume = {16},
year = {2020}
}
@article{Kloster2017,
abstract = {Earth System Models (ESMs) have recently integrated fire processes in their vegetation model components to account for fire as an important disturbance process for vegetation dynamics and agent in the land carbon cycle. The present study analyses the performance of ESMs that participated in the 5th Coupled Model Intercomparison Project (CMIP5) in simulating historical and future fire occurrence. The global present day (1981 to 2005) burned area simulated in the analysed ESMs ranges between 149 and 208Mha, which is substantially lower than the most recent observation based estimate of 399Mha (GFEDv4s averaged over the time period 1997 to 2015). Simulated global fire carbon emissions, however, are with 2.0PgC/year to 2.7PgC/year on the higher end compared to the GFEDv4s estimate of 2.2PgC/year. Regionally, largest differences are found for Africa. Over the historical period (1850 to 2005) changes in simulated fire carbon emissions range between an increase of +43{\%} and a decrease of −35{\%}. For the future (2005 to 2100) we analysed the CMIP5 simulations following the representative concentration pathways (RCPs) 26, 45, and 85, for which the strongest changes in global fire carbon emissions simulated in the single ESMs amount to +8{\%}, +52{\%} and +58{\%}, respectively. Overall, however, there is little agreement between the single ESMs on how fire occurrence changed over the past or will change in the future. Furthermore, contrasting simulated changes in fire carbon emissions and changes in annual mean precipitation shows no emergent pattern among the different analysed ESMs on the regional or global scale. This indicates differences in the single fire model representations that should be subject of upcoming fire model intercomparison studies. The increasing information derived from observational datasets (charcoal, ice-cores, satellite, inventories) will help to further constrain the trajectories of fire models.},
author = {Kloster, Silvia and Lasslop, Gitta},
doi = {10.1016/j.gloplacha.2016.12.017},
isbn = {0921-8181},
journal = {Global and Planetary Change},
pages = {58--69},
title = {{Historical and future fire occurrence (1850 to 2100) simulated in CMIP5 Earth System Models}},
url = {http://www.sciencedirect.com/science/article/pii/S0921818116303770},
volume = {150},
year = {2017}
}
@article{Knauer2017,
author = {Knauer, J{\"{u}}rgen and Zaehle, S{\"{o}}nke and Reichstein, Markus and Medlyn, Belinda E. and Forkel, Matthias and Hagemann, Stefan and Werner, Christiane},
doi = {10.1111/nph.14288},
issn = {0028-646X},
journal = {New Phytologist},
month = {mar},
number = {4},
pages = {1654--1666},
title = {{The response of ecosystem water‐use efficiency to rising atmospheric CO2 concentrations: sensitivity and large‐scale biogeochemical implications}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.14288},
volume = {213},
year = {2017}
}
@article{Knutti2015a,
author = {Knutti, Reto and Rogelj, Joeri},
doi = {10.1007/s10584-015-1340-3},
issn = {0165-0009},
journal = {Climatic Change},
month = {dec},
number = {3},
pages = {361--373},
publisher = {Springer Netherlands},
title = {{The legacy of our CO2 emissions: a clash of scientific facts, politics and ethics}},
url = {http://link.springer.com/10.1007/s10584-015-1340-3},
volume = {133},
year = {2015}
}
@article{bg-13-827-2016,
abstract = {Abstract. Depth profiles of nitrous oxide (N2O) were measured during six cruises to the upwelling area and oxygen minimum zone (OMZ) off Peru in 2009 and 2012/2013, covering both the coastal shelf region and the adjacent open ocean. N2O profiles displayed a strong sensitivity towards oxygen concentrations. Open ocean profiles with distances to the shelf break larger than the first baroclinic Rossby radius of deformation showed a transition from a broad maximum close to the Equator to a double-peak structure south of 5°S where the oxygen minimum was more pronounced. Maximum N2O concentrations in the open ocean were about 80nM. A linear relationship between $\Delta$N2O and apparent oxygen utilization (AOU) could be found for measurements within the upper oxycline, with a slope similar to studies in other oceanic regions. In contrast, N2O profiles close to the shelf revealed a much higher variability, and N2O concentrations higher than 100nM were often observed. The highest N2O concentration measured at the shelf was ∼ 850nM. Due to the extremely sharp oxygen gradients at the shelf, N2O maxima occurred in very shallow water depths of less than 50m. In the coastal area, a linear relationship between $\Delta$N2O and AOU could not be observed as extremely high $\Delta$N2O values were scattered over the full range of oxygen concentrations. The data points that showed the strongest deviation from a linear $\Delta$N2O∕AOU relationship also showed signals of intense nitrogen loss. These results indicate that the coastal upwelling at the Peruvian coast and the subsequent strong remineralization in the water column causes conditions that lead to extreme N2O accumulation, most likely due to the interplay of intense mixing and high rates of remineralization which lead to a rapid switching of the OMZ waters between anoxic and oxic conditions. This, in turn, could trigger incomplete denitrification or pulses of increased nitrification with extreme N2O production.},
author = {Kock, A and Ar{\'{e}}valo-Mart{\'{i}}nez, D. L. and L{\"{o}}scher, C R and Bange, H W},
doi = {10.5194/bg-13-827-2016},
issn = {1726-4189},
journal = {Biogeosciences},
month = {feb},
number = {3},
pages = {827--840},
publisher = {Copernicus Publications},
title = {{Extreme N2O accumulation in the coastal oxygen minimum zone off Peru}},
url = {https://www.biogeosciences.net/13/827/2016/ http://www.biogeosciences.net/13/827/2016/ http://www.biogeosciences.net/13/827/2016/bg-13-827-2016.pdf},
volume = {13},
year = {2016}
}
@article{Kock2012,
abstract = {Abstract. Sea-to-air and diapycnal fluxes of nitrous oxide (N2O) into the mixed layer were determined during three cruises to the upwelling region off Mauritania. Sea-to-air fluxes as well as diapycnal fluxes were elevated close to the shelf break, but elevated sea-to-air fluxes reached further offshore as a result of the offshore transport of upwelled water masses. To calculate a mixed layer budget for N2O we compared the regionally averaged sea-to-air and diapycnal fluxes and estimated the potential contribution of other processes, such as vertical advection and biological N2O production in the mixed layer. Using common parameterizations for the gas transfer velocity, the comparison of the average sea-to-air and diapycnal N2O fluxes indicated that the mean sea-to-air flux is about three to four times larger than the diapycnal flux. Neither vertical and horizontal advection nor biological production were found sufficient to close the mixed layer budget. Instead, the sea-to-air flux, calculated using a parameterization that takes into account the attenuating effect of surfactants on gas exchange, is in the same range as the diapycnal flux. From our observations we conclude that common parameterizations for the gas transfer velocity likely overestimate the air-sea gas exchange within highly productive upwelling zones.},
author = {Kock, A. and Schafstall, J. and Dengler, M. and Brandt, P. and Bange, H. W.},
doi = {10.5194/bg-9-957-2012},
issn = {1726-4189},
journal = {Biogeosciences},
month = {mar},
number = {3},
pages = {957--964},
title = {{Sea-to-air and diapycnal nitrous oxide fluxes in the eastern tropical North Atlantic Ocean}},
url = {https://www.biogeosciences.net/9/957/2012/},
volume = {9},
year = {2012}
}
@article{Koffieaay4444,
abstract = {Wetlands are a major source of methane (CH4) and contribute between 30 and 40{\%} to the total CH4 emissions. Wetland CH4 emissions depend on temperature, water table depth, and both the quantity and quality of organic matter. Global warming will affect these three drivers of methanogenesis, raising questions about the feedbacks between natural methane production and climate change. Until present the large-scale response of wetland CH4 emissions to climate has been investigated with land-surface models that have produced contrasting results. Here, we produce a novel global estimate of wetland methane emissions based on atmospheric inverse modeling of CH4 fluxes and observed temperature and precipitation. Our data-driven model suggests that by 2100, current emissions may increase by 50{\%} to 80{\%}, which is within the range of 50{\%} and 150{\%} reported in previous studies. This finding highlights the importance of limiting global warming below 2{\{}$\backslash$textdegree{\}}C to avoid substantial climate feedbacks driven by methane emissions from natural wetlands.},
author = {Koffi, Ernest N and Bergamaschi, Peter and Alkama, Romain and Cescatti, Alessandro},
doi = {10.1126/sciadv.aay4444},
journal = {Science Advances},
number = {15},
pages = {eaay4444},
publisher = {American Association for the Advancement of Science},
title = {{An observation-constrained assessment of the climate sensitivity and future trajectories of wetland methane emissions}},
url = {https://advances.sciencemag.org/content/6/15/eaay4444},
volume = {6},
year = {2020}
}
@article{Kohnert2017,
abstract = {Arctic permafrost caps vast amounts of old, geologic methane (CH4) in subsurface reservoirs. Thawing permafrost opens pathways for this CH4 to migrate to the surface. However, the occurrence of geologic emissions and their contribution to the CH4 budget in addition to recent, biogenic CH4 is uncertain. Here we present a high-resolution (100 m × 100 m) regional (10,000 km²) CH4 flux map of the Mackenzie Delta, Canada, based on airborne CH4 flux data from July 2012 and 2013. We identify strong, likely geologic emissions solely where the permafrost is discontinuous. These peaks are 13 times larger than typical biogenic emissions. Whereas microbial CH4 production largely depends on recent air and soil temperature, geologic CH4 was produced over millions of years and can be released year-round provided open pathways exist. Therefore, even though they only occur on about 1{\%} of the area, geologic hotspots contribute 17{\%} to the annual CH4 emission estimate of our study area. We suggest that this share may increase if ongoing permafrost thaw opens new pathways. We conclude that, due to permafrost thaw, hydrocarbon-rich areas, prevalent in the Arctic, may see increased emission of geologic CH4 in the future, in addition to enhanced microbial CH4 production.},
author = {Kohnert, Katrin and Serafimovich, Andrei and Metzger, Stefan and Hartmann, J{\"{o}}rg and Sachs, Torsten},
doi = {10.1038/s41598-017-05783-2},
issn = {2045-2322},
journal = {Scientific Reports},
number = {1},
pages = {5828},
title = {{Strong geologic methane emissions from discontinuous terrestrial permafrost in the Mackenzie Delta, Canada}},
url = {https://doi.org/10.1038/s41598-017-05783-2},
volume = {7},
year = {2017}
}
@article{Kone2009,
abstract = {We report partial pressure of CO2 (pCO2) and ancillary data in three rivers (Bia, Tano{\'{e}}, and Como{\'{e}}) and five lagoons (Tendo, Aby, Ebri{\'{e}}, Potou, and Grand-Lahou) in Ivory Coast (West Africa), during four cruises covering the main climatic seasons. The three rivers were oversaturated in CO2 with respect to atmospheric equilibrium, and the seasonal variability of pCO2 was due to dilution during the flooding period. Surface waters of the Potou, Ebri{\'{e}}, and Grand-Lahou lagoons were oversaturated in CO2 during all seasons. These lagoons behaved similarly to the oligohaline regions of macrotidal estuaries that are CO2 sources to the atmosphere due to net ecosystem heterotrophy and inputs of riverine CO2 rich waters. The Aby and Tendo lagoons were undersaturated in CO2 with respect to the atmosphere because of their permanent haline stratification (unlike the other lagoons) that seemed to lead to higher phytoplankton production and export of organic carbon below the pycnocline.},
author = {Kon{\'{e}}, Y J M and Abril, G and Kouadio, K N and Delille, B and Borges, A V},
doi = {10.1007/s12237-008-9121-0},
issn = {1559-2723},
journal = {Estuaries and Coasts},
month = {mar},
number = {2},
pages = {246--260},
title = {{Seasonal Variability of Carbon Dioxide in the Rivers and Lagoons of Ivory Coast (West Africa)}},
url = {https://doi.org/10.1007/s12237-008-9121-0 http://link.springer.com/10.1007/s12237-008-9121-0},
volume = {32},
year = {2009}
}
@article{Kortelainen2020,
author = {Kortelainen, Pirkko and Larmola, Tuula and Rantakari, Miitta and Juutinen, Sari and Alm, Jukka and Martikainen, Pertti J.},
doi = {10.1111/gcb.14928},
issn = {1354-1013},
journal = {Global Change Biology},
month = {mar},
number = {3},
pages = {1432--1445},
title = {{Lakes as nitrous oxide sources in the boreal landscape}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14928},
volume = {26},
year = {2020}
}
@article{M.KoskinenL.MaanaviljaM.NieminenK.Minkkinen2016,
author = {Koskinen, M. and Maanavilja, L. and Nieminen, M. and Minkkinen, K. and Tuittila, E.},
doi = {10.19189/MaP.2015.OMB.202},
journal = {Mires and Peat},
number = {02},
pages = {1--13},
title = {{High methane emissions from restored Norway spruce swamps in southern Finland over one growing season}},
volume = {17},
year = {2016}
}
@article{Kosugi2016a,
abstract = {We made comprehensive surface water CO2 chemistry observations in the Japan Sea during each autumn from 2010 to 2014. The partial pressure of CO2 (pCO2) in surface water, 312–329 $\mu$atm, was 10–30 $\mu$atm lower in the Japan Sea than in the same latitude range of the western North Pacific adjacent to Japan. According to the sensitivity analysis of pCO2, the lower pCO2 in the Japan Sea was primarily attributable to a large seasonal decrease of pCO2 associated with strong cooling in autumn, particularly in the northern Japan Sea. In contrast, the lower pCO2 in relatively warm, freshwater in the southern Japan Sea was attributable to not only the thermodynamic effect of the temperature changes but also high total alkalinity. This alkalinity had its origin in Changjiang River and was transported by Changjiang diluted water (CDW) which seasonally runs into the Japan Sea from the East China Sea. The input of total alkalinity through CDW also elevated the saturation state of calcium carbonate minerals and mitigated the effects of anthropogenic ocean acidification, at least during autumn. These biogeochemical impacts of CDW in the Japan Sea last until November, although the inflow from the East China Sea to the Japan Sea almost ceases by the end of September. The long duration of the high saturation state of calcium carbonate benefits calcareous marine organisms.},
author = {Kosugi, Naohiro and Sasano, Daisuke and Ishii, Masao and Enyo, Kazutaka and Saito, Shu},
doi = {10.1002/2016JC011838},
issn = {21699275},
journal = {Journal of Geophysical Research: Oceans},
month = {aug},
number = {8},
pages = {6536--6549},
title = {{Autumn CO2 chemistry in the Japan Sea and the impact of discharges from the Changjiang River}},
volume = {121},
year = {2016}
}
@article{Koven:2017,
abstract = {The projected loss of soil carbon to the atmosphere resulting from climate change is a potentially large but highly uncertain feedback to warming. The magnitude of this feedback is poorly constrained by observations and theory, and is disparately represented in Earth system models (ESMs)1,2,3. To assess the climatological temperature sensitivity of soil carbon, we calculate apparent soil carbon turnover times4 that reflect long-term and broad-scale rates of decomposition. Here, we show that the climatological temperature control on carbon turnover in the top metre of global soils is more sensitive in cold climates than in warm climates and argue that it is critical to capture this emergent ecosystem property in global-scale models. We present a simplified model that explains the observed high cold-climate sensitivity using only the physical scaling of soil freeze–thaw state across climate gradients. Current ESMs fail to capture this pattern, except in an ESM that explicitly resolves vertical gradients in soil climate and carbon turnover. An observed weak tropical temperature sensitivity emerges in a different model that explicitly resolves mineralogical control on decomposition. These results support projections of strong carbon–climate feedbacks from northern soils5,6 and demonstrate a method for ESMs to capture this emergent behaviour.},
author = {Koven, Charles D and Hugelius, Gustaf and Lawrence, David M and Wieder, William R},
doi = {10.1038/nclimate3421},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {nov},
number = {11},
pages = {817--822},
publisher = {Nature Publishing Group SN -},
title = {{Higher climatological temperature sensitivity of soil carbon in cold than warm climates}},
url = {http://dx.doi.org/10.1038/nclimate3421 http://www.nature.com/articles/nclimate3421},
volume = {7},
year = {2017}
}
@article{Koven:2015c,
abstract = {Abstract. To better understand sources of uncertainty in projections of terrestrial carbon cycle feedbacks, we present an approach to separate the controls on modeled carbon changes. We separate carbon changes into four categories using a linearized, equilibrium approach: those arising from changed inputs (productivity-driven changes), and outputs (turnover-driven changes), of both the live and dead carbon pools. Using Coupled Model Intercomparison Project Phase 5 (CMIP5) simulations for five models, we find that changes to the live pools are primarily explained by productivity-driven changes, with only one model showing large compensating changes to live carbon turnover times. For dead carbon pools, the situation is more complex as all models predict a large reduction in turnover times in response to increases in productivity. This response arises from the common representation of a broad spectrum of decomposition turnover times via a multi-pool approach, in which flux-weighted turnover times are faster than mass-weighted turnover times. This leads to a shift in the distribution of carbon among dead pools in response to changes in inputs, and therefore a transient but long-lived reduction in turnover times. Since this behavior, a reduction in inferred turnover times resulting from an increase in inputs, is superficially similar to priming processes, but occurring without the mechanisms responsible for priming, we call the phenomenon "false priming", and show that it masks much of the intrinsic changes to dead carbon turnover times as a result of changing climate. These patterns hold across the fully coupled, biogeochemically coupled, and radiatively coupled 1 {\%} yr−1 increasing CO2 experiments. We disaggregate inter-model uncertainty in the globally integrated equilibrium carbon responses to initial turnover times, initial productivity, fractional changes in turnover, and fractional changes in productivity. For both the live and dead carbon pools, inter-model spread in carbon changes arising from initial conditions is dominated by model disagreement on turnover times, whereas inter-model spread in carbon changes from fractional changes to these terms is dominated by model disagreement on changes to productivity in response to both warming and CO2 fertilization. However, the lack of changing turnover time control on carbon responses, for both live and dead carbon pools, in response to the imposed forcings may arise from a common lack of process representation behind changing turnover times (e.g., allocation and mortality for live carbon; permafrost, microbial dynamics, and mineral stabilization for dead carbon), rather than a true estimate of the importance of these processes.},
author = {Koven, C D and Chambers, J Q and Georgiou, K and Knox, R and Negron-Juarez, R and Riley, W J and Arora, V K and Brovkin, Victor and Friedlingstein, P and Jones, C D},
doi = {10.5194/bg-12-5211-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {sep},
number = {17},
pages = {5211--5228},
publisher = {Copernicus GmbH on behalf of the European Geosciences Union},
title = {{Controls on terrestrial carbon feedbacks by productivity versus turnover in the CMIP5 Earth System Models}},
url = {https://www.biogeosciences.net/12/5211/2015/},
volume = {12},
year = {2015}
}
@article{Koven2015,
abstract = {Permafrost soils contain enormous amounts of organic carbon whose stability is contingent on remaining frozen. With future warming, these soils may release carbon to the atmosphere and act as a positive feedback to climate change. Significant uncertainty remains on the postthaw carbon dynamics of permafrost-affected ecosystems, in particular since most of the carbon resides at depth where decomposition dynamics may differ from surface soils, and since nitrogen mineralized by decomposition may enhance plant growth. Here we show, using a carbon−nitrogen model that includes permafrost processes forced in an unmitigated warming scenario, that the future carbon balance of the permafrost region is highly sensitive to the decomposability of deeper carbon, with the net balance ranging from 21 Pg C to 164 Pg C losses by 2300. Increased soil nitrogen mineralization reduces nutrient limitations, but the impact of deep nitrogen on the carbon budget is small due to enhanced nitrogen availability from warming surface soils and seasonal asynchrony between deeper nitrogen availability and plant nitrogen demands. Although nitrogen dynamics are highly uncertain, the future carbon balance of this region is projected to hinge more on the rate and extent of permafrost thaw and soil decomposition than on enhanced nitrogen availability for vegetation growth resulting from permafrost thaw.},
author = {Koven, Charles D and Lawrence, David M and Riley, William J},
doi = {10.1073/pnas.1415123112},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {mar},
number = {12},
pages = {3752--3757},
title = {{Permafrost carbon–climate feedback is sensitive to deep soil carbon decomposability but not deep soil nitrogen dynamics}},
url = {http://www.pnas.org/content/112/12/3752 http://www.pnas.org/lookup/doi/10.1073/pnas.1415123112},
volume = {112},
year = {2015}
}
@article{Koven:2015b,
author = {Koven, C D and Schuur, E A G and Sch{\"{a}}del, C and Bohn, T J and Burke, E J and Chen, G. and Chen, X and Ciais, P and Grosse, G and Harden, J W and Hayes, D J and Hugelius, G and Jafarov, E E and Krinner, G and Kuhry, P and Lawrence, D M and MacDougall, A H and Marchenko, S S and McGuire, A D and Natali, S M and Nicolsky, D J and Olefeldt, D and Peng, S and Romanovsky, V E and Schaefer, K M and Strauss, J and Treat, C C and Turetsky, M},
doi = {10.1098/rsta.2014.0423},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {nov},
number = {2054},
pages = {20140423},
title = {{A simplified, data-constrained approach to estimate the permafrost carbon–climate feedback}},
url = {http://rsta.royalsocietypublishing.org/content/373/2054/20140423.abstract http://rsta.royalsocietypublishing.org/lookup/doi/10.1098/rsta.2014.0423},
volume = {373},
year = {2015}
}
@article{Koven2013,
abstract = {Climate change can be thought of in terms of geographical shifts in climate properties. Tracking the geographical movement of analogous climate conditions between historical and future climate model simulations, and calculating the impact of such shifts on vegetation carbon storage, suggests that boreal forests will lose carbon as low-carbon ecosystems shift in.},
author = {Koven, Charles D},
doi = {10.1038/ngeo1801},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {6},
pages = {452--456},
title = {{Boreal carbon loss due to poleward shift in low-carbon ecosystems}},
url = {https://doi.org/10.1038/ngeo1801},
volume = {6},
year = {2013}
}
@article{Krause2017,
abstract = {Abstract. Land management for carbon storage is discussed as being indispensable for climate change mitigation because of its large potential to remove carbon dioxide from the atmosphere, and to avoid further emissions from deforestation. However, the acceptance and feasibility of land-based mitigation projects depends on potential side effects on other important ecosystem functions and their services. Here, we use projections of future land use and land cover for different land-based mitigation options from two land-use models (IMAGE and MAgPIE) and evaluate their effects with a global dynamic vegetation model (LPJ-GUESS). In the land-use models, carbon removal was achieved either via growth of bioenergy crops combined with carbon capture and storage, via avoided deforestation and afforestation, or via a combination of both. We compare these scenarios to a reference scenario without land-based mitigation and analyse the LPJ-GUESS simulations with the aim of assessing synergies and trade-offs across a range of ecosystem service indicators: carbon storage, surface albedo, evapotranspiration, water runoff, crop production, nitrogen loss, and emissions of biogenic volatile organic compounds. In our mitigation simulations cumulative carbon storage by year 2099 ranged between 55 and 89 GtC. Other ecosystem service indicators were influenced heterogeneously both positively and negatively, with large variability across regions and land-use scenarios. Avoided deforestation and afforestation led to an increase in evapotranspiration and enhanced emissions of biogenic volatile organic compounds, and to a decrease in albedo, runoff, and nitrogen loss. Crop production could also decrease in the afforestation scenarios as a result of reduced crop area, especially for MAgPIE land-use patterns, if assumed increases in crop yields cannot be realized. Bioenergy-based climate change mitigation was projected to affect less area globally than in the forest expansion scenarios, and resulted in less pronounced changes in most ecosystem service indicators than forest-based mitigation, but included a possible decrease in nitrogen loss, crop production, and biogenic volatile organic compounds emissions.},
author = {Krause, Andreas and Pugh, Thomas A. M. and Bayer, Anita D. and Doelman, Jonathan C. and Humpen{\"{o}}der, Florian and Anthoni, Peter and Olin, Stefan and Bodirsky, Benjamin L. and Popp, Alexander and Stehfest, Elke and Arneth, Almut},
doi = {10.5194/bg-14-4829-2017},
issn = {1726-4189},
journal = {Biogeosciences},
language = {en},
month = {nov},
number = {21},
pages = {4829--4850},
title = {{Global consequences of afforestation and bioenergy cultivation on ecosystem service indicators}},
url = {https://bg.copernicus.org/articles/14/4829/2017/},
volume = {14},
year = {2017}
}
@article{Kravitz2011,
abstract = {To evaluate the effects of stratospheric geoengineering with sulphate aerosols, we propose standard forcing scenarios to be applied to multiple climate models to compare their results and determine the robustness of their responses. Thus far, different modeling groups have used different forcing scenarios for both global warming and geoengineering, complicating the comparison of results. We recommend four experiments to explore the extent to which geoengineering might offset climate change projected in some of the Climate Model Intercomparison Project 5 experiments. These experiments focus on stratospheric aerosols, but future experiments under this framework may focus on different means of geoengineering.},
author = {Kravitz, Ben and Robock, Alan and Boucher, Olivier and Schmidt, Hauke and Taylor, Karl E. and Stenchikov, Georgiy and Schulz, Michael},
doi = {10.1002/asl.316},
isbn = {1530-261X},
issn = {1530261X},
journal = {Atmospheric Science Letters},
keywords = {CMIP5,Climate modeling,Geoengineering,Model evaluation,Monsoon,SRM},
month = {apr},
number = {2},
pages = {162--167},
pmid = {21190044},
title = {{The Geoengineering Model Intercomparison Project (GeoMIP)}},
url = {http://doi.wiley.com/10.1002/asl.316},
volume = {12},
year = {2011}
}
@article{doi:10.1002/2014GB005011,
abstract = {AbstractLarge amounts of methane hydrate locked up within marine sediments are vulnerable to climate change. Changes in bottom water temperatures may lead to their destabilization and the release of methane into the water column or even the atmosphere. In a multimodel approach, the possible impact of destabilizing methane hydrates onto global climate within the next century is evaluated. The focus is set on changing bottom water temperatures to infer the response of the global methane hydrate inventory to future climate change. Present and future bottom water temperatures are evaluated by the combined use of hindcast high-resolution ocean circulation simulations and climate modeling for the next century. The changing global hydrate inventory is computed using the parameterized transfer function recently proposed by Wallmann et al. (2012). We find that the present-day world's total marine methane hydrate inventory is estimated to be 1146 Gt of methane carbon. Within the next 100 years this global inventory may be reduced by ∼0.03{\%} (releasing ∼473 Mt methane from the seafloor). Compared to the present-day annual emissions of anthropogenic methane, the amount of methane released from melting hydrates by 2100 is small and will not have a major impact on the global climate. On a regional scale, ocean bottom warming over the next 100 years will result in a relatively large decrease in the methane hydrate deposits, with the Arctic and Blake Ridge region, offshore South Carolina, being most affected.},
author = {Kretschmer, Kerstin and Biastoch, Arne and R{\"{u}}pke, Lars and Burwicz, Ewa},
doi = {10.1002/2014GB005011},
journal = {Global Biogeochemical Cycles},
keywords = {climate change,gas hydrates,global estimates,methane},
number = {5},
pages = {610--625},
title = {{Modeling the fate of methane hydrates under global warming}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014GB005011},
volume = {29},
year = {2015}
}
@article{Krishnamohan2020,
abstract = {Abstract Solar geoengineering by deliberate injection of sulfate aerosols in the stratosphere is one of the proposed options to counter anthropogenic climate warming. In this study, we focus on the effect of a specific microphysical property of sulfate aerosols in the stratosphere: hygroscopic growth—the tendency of particles to grow by accumulating water. We show that stratospheric sulfate aerosols, for a given mass of sulfates, cause more cooling when prescribed at the lower levels of the stratosphere because of hygroscopic growth. The larger relative humidity in the lower stratosphere causes an increase in the aerosol size through hygroscopic growth that leads to a larger scattering efficiency. In our study, hygroscopic growth provides an additional cooling of 23$\backslash${\%} (0.7 K) when 20 Mt-SO4 of sulfate aerosols, an amount that approximately offsets the warming due to a doubling of CO2, are prescribed at 100 hPa. The hygroscopic effect becomes weaker at higher levels as relative humidity decreases with height. Hygroscopic growth also leads to secondary effects such as an increase in near-infrared shortwave absorption by the aerosols that causes a decrease in high clouds and an increase in stratospheric water vapor. The altitude dependence of the effects of hygroscopic growth is opposite to that of sedimentation effects or the fast adjustment effects due to aerosol-induced warming identified in a recent study.},
author = {Krishnamohan, K.-P. S.-P. and Bala, Govindasamy and Cao, Long and Duan, Lei and Caldeira, Ken},
doi = {10.1029/2019EF001326},
journal = {Earth's Future},
number = {2},
pages = {e2019EF001326},
title = {{The Climatic Effects of Hygroscopic Growth of Sulfate Aerosols in the Stratosphere}},
volume = {8},
year = {2020}
}
@article{Krishnamohan2019,
author = {Krishnamohan, K.-P. S.-P. and Bala, G and Cao, L and Duan, L and Caldeira, K},
doi = {10.5194/esd-10-885-2019},
journal = {Earth System Dynamics},
number = {4},
pages = {885--900},
title = {{Climate system response to stratospheric sulfate aerosols: sensitivity to altitude of aerosol layer}},
volume = {10},
year = {2019}
}
@article{Krumhardt2019,
author = {Krumhardt, K. M. and Lovenduski, N. S. and Long, M. C. and Levy, M. and Lindsay, K. and Moore, J. K. and Nissen, C.},
doi = {10.1029/2018MS001483},
issn = {1942-2466},
journal = {Journal of Advances in Modeling Earth Systems},
month = {may},
number = {5},
pages = {1418--1437},
title = {{Coccolithophore Growth and Calcification in an Acidified Ocean: Insights From Community Earth System Model Simulations}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018MS001483},
volume = {11},
year = {2019}
}
@article{Kubota2017,
abstract = {Marine calcifying organisms, such as stony corals, are under threat by rapid ocean acidification (OA) arising from the oceanic uptake of anthropogenic CO2. To better understand how organisms and ecosystems will adapt to or be damaged by the resulting environmental changes, field observations are crucial. Here, we show clear evidence, based on boron isotopic ratio ($\delta$11B) measurements, that OA is affecting the pH of the calcification fluid (pHCF) in Porites corals within the western North Pacific Subtropical Gyre at two separate locations, Chichijima Island (Ogasawara Archipelago) and Kikaijima Island. Corals from each location have displayed a rapid decline in $\delta$11B since 1960. A comparison with the pH of the ambient seawater (pHSW) near these islands, estimated from a large number of shipboard measurements of seawater CO2 chemistry and atmospheric CO2, indicates that pHCF is sensitive to changes in pHSW. This suggests that the calcification fluid of corals will become less supersaturated with respect to aragonite by the middle of this century (pHCF = {\~{}}8.3 when pHSW = {\~{}}8.0 in 2050), earlier than previously expected, despite the pHCF-upregulating mechanism of corals.},
author = {Kubota, Kaoru and Yokoyama, Yusuke and Ishikawa, Tsuyoshi and Suzuki, Atsushi and Ishii, Masao},
doi = {10.1038/s41598-017-07680-0},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {7694},
title = {{Rapid decline in pH of coral calcification fluid due to incorporation of anthropogenic CO2}},
url = {https://doi.org/10.1038/s41598-017-07680-0 http://www.nature.com/articles/s41598-017-07680-0},
volume = {7},
year = {2017}
}
@article{Kumarathunge2019,
abstract = {Summary The temperature response of photosynthesis is one of the key factors determining predicted responses to warming in global vegetation models (GVMs). The response may vary geographically, owing to genetic adaptation to climate, and temporally, as a result of acclimation to changes in ambient temperature. Our goal was to develop a robust quantitative global model representing acclimation and adaptation of photosynthetic temperature responses. We quantified and modelled key mechanisms responsible for photosynthetic temperature acclimation and adaptation using a global dataset of photosynthetic CO2 response curves, including data from 141 C3 species from tropical rainforest to Arctic tundra. We separated temperature acclimation and adaptation processes by considering seasonal and common-garden datasets, respectively. The observed global variation in the temperature optimum of photosynthesis was primarily explained by biochemical limitations to photosynthesis, rather than stomatal conductance or respiration. We found acclimation to growth temperature to be a stronger driver of this variation than adaptation to temperature at climate of origin. We developed a summary model to represent photosynthetic temperature responses and showed that it predicted the observed global variation in optimal temperatures with high accuracy. This novel algorithm should enable improved prediction of the function of global ecosystems in a warming climate.},
annote = {doi: 10.1111/nph.15668},
author = {Kumarathunge, Dushan P and Medlyn, Belinda E and Drake, John E and Tjoelker, Mark G and Aspinwall, Michael J and Battaglia, Michael and Cano, Francisco J and Carter, Kelsey R and Cavaleri, Molly A and Cernusak, Lucas A and Chambers, Jeffrey Q and Crous, Kristine Y and {De Kauwe}, Martin G and Dillaway, Dylan N and Dreyer, Erwin and Ellsworth, David S and Ghannoum, Oula and Han, Qingmin and Hikosaka, Kouki and Jensen, Anna M and Kelly, Jeff W G and Kruger, Eric L and Mercado, Lina M and Onoda, Yusuke and Reich, Peter B and Rogers, Alistair and Slot, Martijn and Smith, Nicholas G and Tarvainen, Lasse and Tissue, David T and Togashi, Henrique F and Tribuzy, Edgard S and Uddling, Johan and V{\aa}rhammar, Angelica and Wallin, G{\"{o}}ran and Warren, Jeffrey M and Way, Danielle A},
doi = {10.1111/nph.15668},
issn = {0028-646X},
journal = {New Phytologist},
keywords = {ACi curves,Jmax,Vcmax,climate of origin,global vegetation models (GVMs),growth temperature,maximum carboxylation capacity,maximum electron transport rate},
month = {apr},
number = {2},
pages = {768--784},
publisher = {John Wiley {\&} Sons, Ltd (10.1111)},
title = {{Acclimation and adaptation components of the temperature dependence of plant photosynthesis at the global scale}},
url = {https://doi.org/10.1111/nph.15668},
volume = {222},
year = {2019}
}
@article{Kuypers6478,
abstract = {In many oceanic regions, growth of phytoplankton is nitrogen-limited because fixation of N2 cannot make up for the removal of fixed inorganic nitrogen (NH+ 4, NO- 2, and NO- 3) by anaerobic microbial processes. Globally, 30-50{\%} of the total nitrogen loss occurs in oxygen-minimum zones (OMZs) and is commonly attributed to denitrification (reduction of nitrate to N2 by heterotrophic bacteria). Here, we show that instead, the anammox process (the anaerobic oxidation of ammonium by nitrite to yield N2) is mainly responsible for nitrogen loss in the OMZ waters of one of the most productive regions of the world ocean, the Benguela upwelling system. Our in situ experiments indicate that nitrate is not directly converted to N2 by heterotrophic denitrification in the suboxic zone. In the Benguela system, nutrient profiles, anammox rates, abundances of anammox cells, and specific biomarker lipids indicate that anammox bacteria are responsible for massive losses of fixed nitrogen. We have identified and directly linked anammox bacteria to the removal of fixed inorganic nitrogen in the OMZ waters of an open-ocean setting. We hypothesize that anammox could also be responsible for substantial nitrogen loss from other OMZ waters of the ocean.},
author = {Kuypers, Marcel M M and Lavik, Gaute and Woebken, Dagmar and Schmid, Markus and Fuchs, Bernhard M and Amann, Rudolf and Jorgensen, B. B. and Jetten, Mike S M},
doi = {10.1073/pnas.0502088102},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {may},
number = {18},
pages = {6478--6483},
publisher = {National Academy of Sciences},
title = {{Massive nitrogen loss from the Benguela upwelling system through anaerobic ammonium oxidation}},
url = {https://www.pnas.org/content/102/18/6478 http://www.pnas.org/cgi/doi/10.1073/pnas.0502088102},
volume = {102},
year = {2005}
}
@article{Kwiatkowski2018,
abstract = {How ocean acidification will affect marine organisms depends on changes in both the long-term mean and the short-term temporal variability of carbonate chemistry1–8. Although the decadal-to-centennial response to atmospheric CO2 and climate change is constrained by observations and models1, 9, little is known about corresponding changes in seasonality10–12, particularly for pH. Here we assess the latter by analysing nine earth system models (ESMs) forced with a business-as-usual emissions scenario 13 . During the twenty-first century, the seasonal cycle of surface-ocean pH was attenuated by 16 ± 7{\%}, on average, whereas that for hydrogen ion concentration [H+] was amplified by 81 ± 16{\%}. Simultaneously, the seasonal amplitude of the aragonite saturation state ($\Omega$arag) was attenuated except in the subtropics, where it was amplified. These contrasting changes derive from regionally varying sensitivities of these variables to atmospheric CO2 and climate change and to diverging trends in seasonal extremes in the primary controlling variables (temperature, dissolved inorganic carbon and alkalinity). Projected seasonality changes will tend to exacerbate the impacts of increasing [H+] on marine organisms during the summer and ameliorate the impacts during the winter, although the opposite holds in the high latitudes. Similarly, over most of the ocean, impacts from declining $\Omega$arag are likely to be intensified during the summer and dampened during the winter.},
author = {Kwiatkowski, Lester and Orr, James C.},
doi = {10.1038/s41558-017-0054-0},
issn = {1758-678X},
journal = {Nature Climate Change},
keywords = {Biogeochemistry,Climate,Marine chemistry,change impacts},
month = {feb},
number = {2},
pages = {141--145},
publisher = {Nature Publishing Group},
title = {{Diverging seasonal extremes for ocean acidification during the twenty-first century}},
url = {http://www.nature.com/articles/s41558-017-0054-0},
volume = {8},
year = {2018}
}
@article{RN623,
abstract = {Marine primary production is a fundamental component of the Earth system, providing the main source of food and energy to the marine food web, and influencing the concentration of atmospheric CO 2 (refs 1,2). Earth system model (ESM) projections of global marine primary production are highly uncertain with models projecting both increases3,4 and declines of up to 20{\%} by 21005,6. This uncertainty is predominantly driven by the sensitivity of tropical ocean primary production to climate change, with the latest ESMs suggesting twenty-first-century tropical declines of between 1 and 30{\%} (refs 5,6). Here we identify an emergent relationship7,8,9,10,11 between the long-term sensitivity of tropical ocean primary production to rising equatorial zone sea surface temperature (SST) and the interannual sensitivity of primary production to El Ni{\~{n}}o/Southern Oscillation (ENSO)-driven SST anomalies. Satellite-based observations of the ENSO sensitivity of tropical primary production are then used to constrain projections of the long-term climate impact on primary production. We estimate that tropical primary production will decline by 3 ± 1{\%} per kelvin increase in equatorial zone SST. Under a business-as-usual emissions scenario this results in an 11 ± 6{\%} decline in tropical marine primary production and a 6 ± 3{\%} decline in global marine primary production by 2100.},
author = {Kwiatkowski, Lester and Bopp, Laurent and Aumont, Olivier and Ciais, Philippe and Cox, Peter M and Laufk{\"{o}}tter, Charlotte and Li, Yue and S{\'{e}}f{\'{e}}rian, Roland},
doi = {10.1038/nclimate3265},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {may},
number = {5},
pages = {355--358},
title = {{Emergent constraints on projections of declining primary production in the tropical oceans}},
type = {Journal Article},
url = {http://www.nature.com/articles/nclimate3265 https://doi.org/10.1038/nclimate3265},
volume = {7},
year = {2017}
}
@article{Kwiatkowski2020,
abstract = {Abstract. Anthropogenic climate change is projected to lead to ocean warming, acidification, deoxygenation, reductions in near-surface nutrients, and changes to primary production, all of which are expected to affect marine ecosystems. Here we assess projections of these drivers of environmental change over the twenty-first century from Earth system models (ESMs) participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6) that were forced under the CMIP6 Shared Socioeconomic Pathways (SSPs). Projections are compared to those from the previous generation (CMIP5) forced under the Representative Concentration Pathways (RCPs). A total of 10 CMIP5 and 13 CMIP6 models are used in the two multi-model ensembles. Under the high-emission scenario SSP5-8.5, the multi-model global mean change (2080–2099 mean values relative to 1870–1899) ± the inter-model SD in sea surface temperature, surface pH, subsurface (100–600 m) oxygen concentration, euphotic (0–100 m) nitrate concentration, and depth-integrated primary production is +3.47±0.78 ∘C, -0.44±0.005, -13.27±5.28, -1.06±0.45 mmol m−3 and -2.99±9.11 {\%}, respectively. Under the low-emission, high-mitigation scenario SSP1-2.6, the corresponding global changes are +1.42±0.32 ∘C, -0.16±0.002, -6.36±2.92, -0.52±0.23 mmol m−3, and -0.56±4.12 {\%}. Projected exposure of the marine ecosystem to these drivers of ocean change depends largely on the extent of future emissions, consistent with previous studies. The ESMs in CMIP6 generally project greater warming, acidification, deoxygenation, and nitrate reductions but lesser primary production declines than those from CMIP5 under comparable radiative forcing. The increased projected ocean warming results from a general increase in the climate sensitivity of CMIP6 models relative to those of CMIP5. This enhanced warming increases upper-ocean stratification in CMIP6 projections, which contributes to greater reductions in upper-ocean nitrate and subsurface oxygen ventilation. The greater surface acidification in CMIP6 is primarily a consequence of the SSPs having higher associated atmospheric CO2 concentrations than their RCP analogues for the same radiative forcing. We find no consistent reduction in inter-model uncertainties, and even an increase in net primary production inter-model uncertainties in CMIP6, as compared to CMIP5.},
author = {Kwiatkowski, Lester and Torres, Olivier and Bopp, Laurent and Aumont, Olivier and Chamberlain, Matthew and Christian, James R. and Dunne, John P. and Gehlen, Marion and Ilyina, Tatiana and John, Jasmin G. and Lenton, Andrew and Li, Hongmei and Lovenduski, Nicole S. and Orr, James C. and Palmieri, Julien and Santana-Falc{\'{o}}n, Yeray and Schwinger, J{\"{o}}rg and S{\'{e}}f{\'{e}}rian, Roland and Stock, Charles A. and Tagliabue, Alessandro and Takano, Yohei and Tjiputra, Jerry and Toyama, Katsuya and Tsujino, Hiroyuki and Watanabe, Michio and Yamamoto, Akitomo and Yool, Andrew and Ziehn, Tilo},
doi = {10.5194/bg-17-3439-2020},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jul},
number = {13},
pages = {3439--3470},
publisher = {Copernicus Publications},
title = {{Twenty-first century ocean warming, acidification, deoxygenation, and upper-ocean nutrient and primary production decline from CMIP6 model projections}},
url = {https://bg.copernicus.org/articles/17/3439/2020/ https://bg.copernicus.org/articles/17/3439/2020/bg-17-3439-2020.pdf https://www.biogeosciences.net/17/3439/2020/},
volume = {17},
year = {2020}
}
@article{Luthi2008,
abstract = {Changes in past atmospheric carbon dioxide concentrations can be determined by measuring the composition of air trapped in ice cores from Antarctica. So far, the Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric carbon dioxide levels over the past 650,000 years1,2,3,4. Here we present results of the lowest 200 m of the Dome C ice core, extending the record of atmospheric carbon dioxide concentration by two complete glacial cycles to 800,000 yr before present. From previously published data1,2,3,4,5,6,7,8 and the present work, we find that atmospheric carbon dioxide is strongly correlated with Antarctic temperature throughout eight glacial cycles but with significantly lower concentrations between 650,000 and 750,000 yr before present. Carbon dioxide levels are below 180 parts per million by volume (p.p.m.v.) for a period of 3,000 yr during Marine Isotope Stage 16, possibly reflecting more pronounced oceanic carbon storage. We report the lowest carbon dioxide concentration measured in an ice core, which extends the pre-industrial range of carbon dioxide concentrations during the late Quaternary by about 10 p.p.m.v. to 172–300 p.p.m.v.},
author = {L{\"{u}}thi, Dieter and {Le Floch}, Martine and Bereiter, Bernhard and Blunier, Thomas and Barnola, Jean-Marc and Siegenthaler, Urs and Raynaud, Dominique and Jouzel, Jean and Fischer, Hubertus and Kawamura, Kenji and Stocker, Thomas F.},
doi = {10.1038/nature06949},
issn = {0028-0836},
journal = {Nature},
month = {may},
number = {7193},
pages = {379--382},
publisher = {Nature Publishing Group},
title = {{High-resolution carbon dioxide concentration record 650,000–800,000 years before present}},
url = {http://www.nature.com/doifinder/10.1038/nature06949},
volume = {453},
year = {2008}
}
@article{Lade2018,
abstract = {Abstract. Changes to climate–carbon cycle feedbacks may significantly affect the Earth system's response to greenhouse gas emissions. These feedbacks are usually analysed from numerical output of complex and arguably opaque Earth system models. Here, we construct a stylised global climate–carbon cycle model, test its output against comprehensive Earth system models, and investigate the strengths of its climate–carbon cycle feedbacks analytically. The analytical expressions we obtain aid understanding of carbon cycle feedbacks and the operation of the carbon cycle. Specific results include that different feedback formalisms measure fundamentally the same climate–carbon cycle processes; temperature dependence of the solubility pump, biological pump, and CO2 solubility all contribute approximately equally to the ocean climate–carbon feedback; and concentration–carbon feedbacks may be more sensitive to future climate change than climate–carbon feedbacks. Simple models such as that developed here also provide workbenches for simple but mechanistically based explorations of Earth system processes, such as interactions and feedbacks between the planetary boundaries, that are currently too uncertain to be included in comprehensive Earth system models.},
author = {Lade, Steven J and Donges, Jonathan F and Fetzer, Ingo and Anderies, John M and Beer, Christian and Cornell, Sarah E and Gasser, Thomas and Norberg, Jon and Richardson, Katherine and Rockstr{\"{o}}m, Johan and Steffen, Will},
doi = {10.5194/esd-9-507-2018},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {may},
number = {2},
pages = {507--523},
title = {{Analytically tractable climate–carbon cycle feedbacks under 21st century anthropogenic forcing}},
url = {https://www.earth-syst-dynam.net/9/507/2018/},
volume = {9},
year = {2018}
}
@article{Lamarche-Gagnon2019,
abstract = {Ice sheets are currently ignored in global methane budgets1,2. Although ice sheets have been proposed to contain large reserves of methane that may contribute to a rise in atmospheric methane concentration if released during periods of rapid ice retreat3,4, no data exist on the current methane footprint of ice sheets. Here we find that subglacially produced methane is rapidly driven to the ice margin by the efficient drainage system of a subglacial catchment of the Greenland ice sheet. We report the continuous export of methane-supersaturated waters (CH4(aq)) from the ice-sheet bed during the melt season. Pulses of high CH4(aq) concentration coincide with supraglacially forced subglacial flushing events, confirming a subglacial source and highlighting the influence of melt on methane export. Sustained methane fluxes over the melt season are indicative of subglacial methane reserves that exceed methane export, with an estimated 6.3 tonnes (discharge-weighted mean; range from 2.4 to 11 tonnes) of CH4(aq) transported laterally from the ice-sheet bed. Stable-isotope analyses reveal a microbial origin for methane, probably from a mixture of inorganic and ancient organic carbon buried beneath the ice. We show that subglacial hydrology is crucial for controlling methane fluxes from the ice sheet, with efficient drainage limiting the extent of methane oxidation5 to about 17 per cent of methane exported. Atmospheric evasion is the main methane sink once runoff reaches the ice margin, with estimated diffusive fluxes (4.4 to 28 millimoles of CH4 per square metre per day) rivalling that of major world rivers6. Overall, our results indicate that ice sheets overlie extensive, biologically active methanogenic wetlands and that high rates of methane export to the atmosphere can occur via efficient subglacial drainage pathways. Our findings suggest that such environments have been previously underappreciated and should be considered in Earth's methane budget.},
author = {Lamarche-Gagnon, Guillaume and Wadham, Jemma L. and {Sherwood Lollar}, Barbara and Arndt, Sandra and Fietzek, Peer and Beaton, Alexander D. and Tedstone, Andrew J. and Telling, Jon and Bagshaw, Elizabeth A. and Hawkings, Jon R. and Kohler, Tyler J. and Zarsky, Jakub D. and Mowlem, Matthew C. and Anesio, Alexandre M. and Stibal, Marek},
doi = {10.1038/s41586-018-0800-0},
issn = {0028-0836},
journal = {Nature},
month = {jan},
number = {7737},
pages = {73--77},
title = {{Greenland melt drives continuous export of methane from the ice-sheet bed}},
url = {http://www.nature.com/articles/s41586-018-0800-0},
volume = {565},
year = {2019}
}
@article{Lambert2021,
abstract = {The last time Earth's climate experienced geologically rapid global warming was associated with the last glacial termination, when atmospheric CO2 concentrations rose from 180 ppmv during the Last Glacial Maximum (LGM, 26-19 kaBP) to ∼260 ppmv by the early Holocene (12-8 kaBP). About one quarter of that difference is thought to be due to a stronger biological pump during glacial times, driven by increased aeolian dust deposition and hence greater iron availability in ocean surface waters. However, dust supply did not change uniformly or in synchrony over the deglacial transition and what is not known is the relative importance of different oceanic regions and how this may have changed in time. Using an Earth system model of intermediate complexity, we quantify the sensitivity of atmospheric CO2 to regional changes in iron supply, and test six different global dust reconstructions in order to explore uncertainty in past dust changes. We confirm the Southern Ocean ({\textgreater}34°S) as the region most sensitive to iron fertilization, with the Atlantic and Pacific sectors accounting for about 41±23{\%} and 16±10{\%}, respectively, of the total CO2 reduction from global iron fertilization. However, the North Pacific contributes 28±3{\%} to the total implying an important role for Northern Hemisphere processes in driving deglacial CO2 rise. In addition, our analysis reveals an unexpected regional-temporal disparity, and while Southern Hemisphere iron fertilization influences atmospheric CO2 relatively constantly throughout the termination the impact of the Northern Hemisphere only occurs during the later stages of the termination.},
author = {Lambert, Fabrice and Opazo, Natalia and Ridgwell, Andy and Winckler, Gisela and Lamy, Frank and Shaffer, Gary and Kohfeld, Karen and Ohgaito, Rumi and Albani, Samuel and Abe-Ouchi, Ayako},
doi = {10.1016/j.epsl.2020.116675},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {CO2,dust,iron fertilization,paleoclimate,termination},
pages = {116675},
title = {{Regional patterns and temporal evolution of ocean iron fertilization and CO2 drawdown during the last glacial termination}},
volume = {554},
year = {2021}
}
@article{Lan2019,
author = {Lan, Xin and Tans, Pieter and Sweeney, Colm and Andrews, Arlyn and Dlugokencky, Edward and Schwietzke, Stefan and Kofler, Jonathan and McKain, Kathryn and Thoning, Kirk and Crotwell, Molly and Montzka, Stephen and Miller, Benjamin R. and Biraud, S{\'{e}}bastien C.},
doi = {10.1029/2018GL081731},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {may},
number = {9},
pages = {4991--4999},
title = {{Long‐Term Measurements Show Little Evidence for Large Increases in Total U.S. Methane Emissions Over the Past Decade}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL081731},
volume = {46},
year = {2019}
}
@article{Landolfi2017,
author = {Landolfi, A. and Somes, C. J. and Koeve, W. and Zamora, L. M. and Oschlies, A.},
doi = {10.1002/2017GB005633},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {aug},
number = {8},
pages = {1236--1255},
title = {{Oceanic nitrogen cycling and N2 flux perturbations in the Anthropocene}},
url = {http://doi.wiley.com/10.1002/2017GB005633},
volume = {31},
year = {2017}
}
@article{Landschutzer2018,
abstract = {The increase of atmospheric CO2 (ref. 1) has been predicted to impact the seasonal cycle of inorganic carbon in the global ocean2,3, yet the observational evidence to verify this prediction has been missing. Here, using an observation-based product of the oceanic partial pressure of CO2 (pCO2) covering the past 34 years, we find that the winter-to-summer difference of the pCO2 has increased on average by 2.2 ± 0.4 $\mu$atm per decade from 1982 to 2015 poleward of 10° latitude. This is largely in agreement with the trend expected from thermodynamic considerations. Most of the increase stems from the seasonality of the drivers acting on an increasing oceanic pCO2 caused by the uptake of anthropogenic CO2 from the atmosphere. In the high latitudes, the concurrent ocean-acidification-induced changes in the buffer capacity of the ocean enhance this effect. This strengthening of the seasonal winter-to-summer difference pushes the global ocean towards critical thresholds earlier, inducing stress to ocean ecosystems and fisheries4. Our study provides observational evidence for this strengthening seasonal difference in the oceanic carbon cycle on a global scale, illustrating the inevitable consequences of anthropogenic CO2 emissions.},
author = {Landsch{\"{u}}tzer, Peter and Gruber, Nicolas and Bakker, Dorothee C E and Stemmler, Irene and Six, Katharina D},
doi = {10.1038/s41558-017-0057-x},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {feb},
number = {2},
pages = {146--150},
title = {{Strengthening seasonal marine CO2 variations due to increasing atmospheric CO2}},
url = {https://doi.org/10.1038/s41558-017-0057-x http://www.nature.com/articles/s41558-017-0057-x},
volume = {8},
year = {2018}
}
@article{Landschutzer2015,
abstract = {Has global warming slowed the uptake of atmospheric CO2 by the Southern Ocean? Landsch{\"{u}}tzer et al. say no (see the Perspective by Fletcher). Previous work suggested that the strength of the Southern Ocean carbon sink fell during the 1990s. This raised concerns that such a decline would exacerbate the rise of atmospheric CO2 and thereby increase global surface air temperatures and ocean acidity. The newer data show that the Southern Ocean carbon sink strengthened again over the past decade, which illustrates the dynamic nature of the process and alleviates some of the anxiety about its earlier weakening trend.Science, this issue p. 1221; see also p. 1165Several studies have suggested that the carbon sink in the Southern Ocean—the ocean's strongest region for the uptake of anthropogenic CO2 —has weakened in recent decades. We demonstrated, on the basis of multidecadal analyses of surface ocean CO2 observations, that this weakening trend stopped around 2002, and by 2012, the Southern Ocean had regained its expected strength based on the growth of atmospheric CO2. All three Southern Ocean sectors have contributed to this reinvigoration of the carbon sink, yet differences in the processes between sectors exist, related to a tendency toward a zonally more asymmetric atmospheric circulation. The large decadal variations in the Southern Ocean carbon sink suggest a rather dynamic ocean carbon cycle that varies more in time than previously recognized.},
author = {Landsch{\"{u}}tzer, Peter and Gruber, Nicolas and Haumann, F Alexander and R{\"{o}}denbeck, Christian and Bakker, Dorothee C E and van Heuven, Steven and Hoppema, Mario and Metzl, Nicolas and Sweeney, Colm and Takahashi, Taro and Tilbrook, Bronte and Wanninkhof, Rik},
doi = {10.1126/science.aab2620},
issn = {0036-8075},
journal = {Science},
month = {sep},
number = {6253},
pages = {1221--1224},
title = {{The reinvigoration of the Southern Ocean carbon sink}},
url = {http://science.sciencemag.org/content/349/6253/1221.abstract http://www.sciencemag.org/lookup/doi/10.1126/science.aab2620},
volume = {349},
year = {2015}
}
@article{Landschutzer2014,
abstract = {We present a new observation‐based estimate of the global oceanic carbon dioxide (CO2) sink and its temporal variation on a monthly basis from 1998 through 2011 and at a spatial resolution of 1°×1°. This sink estimate rests upon a neural network‐based mapping of global surface ocean observations of the partial pressure of CO2 (pCO2) from the Surface Ocean CO2 Atlas database. The resulting pCO2 has small biases when evaluated against independent observations in the different ocean basins, but larger randomly distributed differences exist particularly in high latitudes. The seasonal climatology of our neural network‐based product agrees overall well with the Takahashi et al. (2009) climatology, although our product produces a stronger seasonal cycle at high latitudes. From our global pCO2 product, we compute a mean net global ocean (excluding the Arctic Ocean and coastal regions) CO2 uptake flux of −1.42 ± 0.53 Pg C yr−1, which is in good agreement with ocean inversion‐based estimates. Our data indicate a moderate level of interannual variability in the ocean carbon sink (±0.12 Pg C yr−1, 1$\sigma$) from 1998 through 2011, mostly originating from the equatorial Pacific Ocean, and associated with the El Ni{\~{n}}o–Southern Oscillation. Accounting for steady state riverine and Arctic Ocean carbon fluxes our estimate further implies a mean anthropogenic CO2 uptake of −1.99 ± 0.59 Pg C yr−1 over the analysis period. From this estimate plus the most recent estimates for fossil fuel emissions and atmospheric CO2 accumulation, we infer a mean global land sink of −2.82 ± 0.85 Pg C yr−1 over the 1998 through 2011 period with strong interannual variation.},
author = {Landsch{\"{u}}tzer, P. and Gruber, N. and Bakker, D. C. E. and Schuster, U.},
doi = {10.1002/2014GB004853},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {sep},
number = {9},
pages = {927--949},
publisher = {Wiley-Blackwell},
title = {{Recent variability of the global ocean carbon sink}},
url = {http://doi.wiley.com/10.1002/2014GB004853},
volume = {28},
year = {2014}
}
@article{Landschutzer2016,
abstract = {We investigate the variations of the ocean CO2 sink during the past three decades using global surface ocean maps of the partial pressure of CO2 reconstructed from observations contained in the Surface Ocean CO2 Atlas Version 2. To create these maps, we used the neural network‐based data interpolation method of Landsch{\"{u}}tzer et al. (2014) but extended the work in time from 1998 to 2011 to the period from 1982 through 2011. Our results suggest strong decadal variations in the global ocean carbon sink around a long‐term increase that corresponds roughly to that expected from the rise in atmospheric CO2. The sink is estimated to have weakened during the 1990s toward a minimum uptake of only −0.8 ± 0.5 Pg C yr−1 in 2000 and thereafter to have strengthened considerably to rates of more than −2.0 ± 0.5 Pg C yr−1. These decadal variations originate mostly from the extratropical oceans, while the tropical regions contribute primarily to interannual variations. Changes in sea surface temperature affecting the solubility of CO2 explain part of these variations, particularly at subtropical latitudes. But most of the higher‐latitude changes are attributed to modifications in the surface concentration of dissolved inorganic carbon and alkalinity, induced by decadal variations in atmospheric forcing, with patterns that are reminiscent of those of the Northern and Southern Annular Modes. These decadal variations lead to a substantially smaller cumulative anthropogenic CO2 uptake of the ocean over the 1982 through 2011 period (reduction of 7.5 ± 5.5 Pg C) relative to that derived by the Global Carbon Budget.},
author = {Landsch{\"{u}}tzer, Peter and Gruber, Nicolas and Bakker, Dorothee C. E.},
doi = {10.1002/2015GB005359},
journal = {Global Biogeochemical Cycles},
month = {oct},
number = {10},
pages = {1396--1417},
publisher = {Wiley-Blackwell},
title = {{Decadal variations and trends of the global ocean carbon sink}},
url = {http://doi.wiley.com/10.1002/2015GB005359},
volume = {30},
year = {2016}
}
@article{Landschutzer2019,
author = {Landsch{\"{u}}tzer, Peter and Ilyina, Tatiana and Lovenduski, Nicole S.},
doi = {10.1029/2018GL081756},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {mar},
number = {5},
pages = {2670--2679},
title = {{Detecting Regional Modes of Variability in Observation-Based Surface Ocean pCO2}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL081756},
volume = {46},
year = {2019}
}
@article{Landschutzer2020a,
abstract = {In this study, we present the first combined open- and coastal-ocean pCO2 mapped monthly climatology (Landsch{\"{u}}tzer et al., 2020b, https://doi.org/10.25921/qb25-f418, https://www.nodc.noaa.gov/ocads/ oceans/MPI-ULB-SOM{\_}FFN{\_}clim.html, last access: 8 April 2020) constructed from observations collected between 1998 and 2015 extracted from the Surface Ocean CO2 Atlas (SOCAT) database. We combine two neural network-based pCO2 products, one from the open ocean and the other from the coastal ocean, and investigate their consistency along their common overlap areas. While the difference between open- and coastal-ocean estimates along the overlap area increases with latitude, it remains close to 0 $\mu$atm globally. Stronger discrepancies, however, exist on the regional level resulting in differences that exceed 10{\%} of the climatological mean pCO2, or an order of magnitude larger than the uncertainty from state-of-the-art measurements. This also illustrates the potential of such an analysis to highlight where we lack a good representation of the aquatic continuum and future research should be dedicated. A regional analysis further shows that the seasonal carbon dynamics at the coast-open interface are well represented in our climatology. While our combined product is only a first step towards a true representation of both the open-ocean and the coastal-ocean air-sea CO2 flux in marine carbon budgets, we show it is a feasible task and the present data product already constitutes a valuable tool to investigate and quantify the dynamics of the air-sea CO2 exchange consistently for oceanic regions regardless of its distance to the coast.},
author = {Landsch{\"{u}}tzer, Peter and Laruelle, Goulven G. and Roobaert, Alizee and Regnier, Pierre},
doi = {10.5194/essd-12-2537-2020},
issn = {18663516},
journal = {Earth System Science Data},
month = {oct},
number = {4},
pages = {2537--2553},
publisher = {Copernicus GmbH},
title = {{A uniform pCO2 climatology combining open and coastal oceans}},
volume = {12},
year = {2020}
}
@article{Laruelle2014,
abstract = {Over the past decade, estimates of the atmospheric CO2 uptake by continental shelf seas were constrained within the 0.18–0.45 Pg C yr−1 range. However, most of those estimates are based on extrapolations from limited data sets of local flux measurements (n {\textless} 100). Here we propose to derive the CO2 air-sea exchange of the shelf seas by extracting 3 {\textperiodcentered} 106 direct surface ocean CO2 measurements from the global database SOCAT (Surface Ocean CO2 Atlas), atmospheric CO2 values from GlobalVIEW and calculating gas transfer rates using readily available global temperature, salinity, and wind speed fields. We then aggregate our results using a global segmentation of the shelf in 45 units and 152 subunits to establish a consistent regionalized CO2 exchange budget at the global scale. Within each unit, the data density determines the spatial and temporal resolutions at which the air-sea CO2 fluxes are calculated and range from a 0.5° resolution in the best surveyed regions to a whole unit resolution in areas where data coverage is limited. Our approach also accounts, for the first time, for the partial sea ice cover of polar shelves. Our new regionalized global CO2 sink estimate of 0.19 ± 0.05 Pg C yr−1 falls in the low end of previous estimates. Reported to an ice-free surface area of 22 {\textperiodcentered} 106 km2, this value yields a flux density of 0.7 mol C m−2 yr−1, {\~{}}40{\%} more intense than that of the open ocean. Our results also highlight the significant contribution of Arctic shelves to this global CO2 uptake (0.07 Pg C yr−1).},
author = {Laruelle, Goulven G and Lauerwald, Ronny and Pfeil, Benjamin and Regnier, Pierre},
doi = {10.1002/2014GB004832},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {0428 Carbon cycling,4219 Continental shelf and slope processes,4504 Air/sea interactions,CO2,carbon cycle,coastal ocean},
month = {nov},
number = {11},
pages = {1199--1214},
title = {{Regionalized global budget of the CO2 exchange at the air-water interface in continental shelf seas}},
url = {http://dx.doi.org/10.1002/2014GB004832 http://doi.wiley.com/10.1002/2014GB004832},
volume = {28},
year = {2014}
}
@article{Laruelle2017a,
abstract = {Abstract. In spite of the recent strong increase in the number of measurements of the partial pressure of CO2 in the surface ocean (pCO2), the air–sea CO2 balance of the continental shelf seas remains poorly quantified. This is a consequence of these regions remaining strongly under-sampled in both time and space and of surface pCO2 exhibiting much higher temporal and spatial variability in these regions compared to the open ocean. Here, we use a modified version of a two-step artificial neural network method (SOM-FFN; Landsch{\"{u}}tzer et al., 2013) to interpolate the pCO2 data along the continental margins with a spatial resolution of 0.25° and with monthly resolution from 1998 to 2015. The most important modifications compared to the original SOM-FFN method are (i) the much higher spatial resolution and (ii) the inclusion of sea ice and wind speed as predictors of pCO2. The SOM-FFN is first trained with pCO2 measurements extracted from the SOCATv4 database. Then, the validity of our interpolation, in both space and time, is assessed by comparing the generated pCO2 field with independent data extracted from the LDVEO2015 database. The new coastal pCO2 product confirms a previously suggested general meridional trend of the annual mean pCO2 in all the continental shelves with high values in the tropics and dropping to values beneath those of the atmosphere at higher latitudes. The monthly resolution of our data product permits us to reveal significant differences in the seasonality of pCO2 across the ocean basins. The shelves of the western and northern Pacific, as well as the shelves in the temperate northern Atlantic, display particularly pronounced seasonal variations in pCO2, while the shelves in the southeastern Atlantic and in the southern Pacific reveal a much smaller seasonality. The calculation of temperature normalized pCO2 for several latitudes in different oceanic basins confirms that the seasonality in shelf pCO2 cannot solely be explained by temperature-induced changes in solubility but are also the result of seasonal changes in circulation, mixing and biological productivity. Our results also reveal that the amplitudes of both thermal and nonthermal seasonal variations in pCO2 are significantly larger at high latitudes. Finally, because this product's spatial extent includes parts of the open ocean as well, it can be readily merged with existing global open-ocean products to produce a true global perspective of the spatial and temporal variabi{\ldots}},
author = {Laruelle, Goulven G. and Landsch{\"{u}}tzer, Peter and Gruber, Nicolas and Tison, Jean-Louis and Delille, Bruno and Regnier, Pierre},
doi = {10.5194/bg-14-4545-2017},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {19},
pages = {4545--4561},
title = {{Global high-resolution monthly CO2 climatology for the coastal ocean derived from neural network interpolation}},
volume = {14},
year = {2017}
}
@article{Laruelle2018a,
abstract = {It has been speculated that the partial pressure of carbon dioxide (pCO2) in shelf waters may lag the rise in atmospheric CO2. Here, we show that this is the case across many shelf regions, implying a tendency for enhanced shelf uptake of atmospheric CO2. This result is based on analysis of long-term trends in the air–sea pCO2 gradient ($\Delta$pCO2) using a global surface ocean pCO2 database spanning a period of up to 35 years. Using wintertime data only, we find that $\Delta$pCO2 increased in 653 of the 825 0.5° cells for which a trend could be calculated, with 325 of these cells showing a significant increase in excess of +0.5 $\mu$atm yr−1 (p {\textless} 0.05). Although noisier, the deseasonalized annual data suggest similar results. If this were a global trend, it would support the idea that shelves might have switched from a source to a sink of CO2 during the last century.},
author = {Laruelle, Goulven G. and Cai, Wei-Jun and Hu, Xinping and Gruber, Nicolas and Mackenzie, Fred T. and Regnier, Pierre},
doi = {10.1038/s41467-017-02738-z},
issn = {2041-1723},
journal = {Nature Communications},
keywords = {Carbon cycle,Marine chemistry},
month = {dec},
number = {1},
pages = {454},
publisher = {Nature Publishing Group},
title = {{Continental shelves as a variable but increasing global sink for atmospheric carbon dioxide}},
url = {https://doi.org/10.1038/s41467-017-02738-z http://www.nature.com/articles/s41467-017-02738-z},
volume = {9},
year = {2018}
}
@article{Lassey2007,
abstract = {Little is known about how the methane source inventory and sinks have evolved over recent centuries. New and detailed records of methane mixing ratio and isotopic composition (12CH4, 13CH4 and 14CH4) from analyses of air trapped in polar ice and firn can enhance this knowledge. We use existing bottom-up constructions of the source history, including "EDGAR"-based constructions, as inputs to a model of the evolving global budget for methane and for its carbon isotope composition through the 20th century. By matching such budgets to atmospheric data, we examine the constraints imposed by isotope information on those budget evolutions. Reconciling both 12CH4 and 13CH4 budgets with EDGAR-based source histories requires a combination of: a greater proportion of emissions from biomass burning and/or of fossil methane than EDGAR constructions suggest; a greater contribution from natural such emissions than is commonly supposed; and/or a significant role for active chlorine or other highly-fractionating tropospheric sink as has been independently proposed. Examining a companion budget evolution for 14CH4 exposes uncertainties in inferring the fossil-methane source from atmospheric 14CH4 data. Specifically, methane evolution during the nuclear era is sensitive to the cycling dynamics of "bomb 14C" (originating from atmospheric weapons tests) through the biosphere. In addition, since ca. 1970, direct production and release of 14CH4 from nuclear-power facilities is influential but poorly quantified. Atmospheric 14CH4 determinations in the nuclear era have the potential to better characterize both biospheric carbon cycling, from photosynthesis to methane synthesis, and the nuclear-power source.},
author = {Lassey, K. R. and Etheridge, D. M. and Lowe, D. C. and Smith, A. M. and Ferretti, D. F.},
doi = {10.5194/acp-7-2119-2007},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {may},
number = {8},
pages = {2119--2139},
title = {{Centennial evolution of the atmospheric methane budget: what do the carbon isotopes tell us?}},
url = {http://www.atmos-chem-phys.net/7/2119/2007/},
volume = {7},
year = {2007}
}
@article{doi:10.1002/2016GL069365,
abstract = {Abstract The presence of multiple stable states has far-reaching consequences for a system's susceptibility to disturbances, including the possibility of abrupt transitions between stable states. The occurrence of multiple stable states of vegetation is supported by ecological theory, models, and observations. Here we describe the occurrence of multiple stable states of tree cover in a global dynamic vegetation model and provide the first global picture on multiple stable states of tree cover due to a fire-vegetation feedback. The multiple stable states occur in the transition zones between grasslands and forests, mainly in Africa and Asia. By sensitivity simulations and simplifying the relevant model equations we show that the occurrence of multiple states is caused by the sensitivity of the fire disturbance rate to the presence of woody plant types.},
annote = {added by A.Eliseev 25.01.2019},
author = {Lasslop, G and Brovkin, V and Reick, C H and Bathiany, S and Kloster, S},
doi = {10.1002/2016GL069365},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {fire-vegetation feedback,global fire modeling,multiple stable states of tree cover},
month = {jun},
number = {12},
pages = {6324--6331},
title = {{Multiple stable states of tree cover in a global land surface model due to a fire-vegetation feedback}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016GL069365 http://doi.wiley.com/10.1002/2016GL069365},
volume = {43},
year = {2016}
}
@article{Lasslop2020,
abstract = {Abstract In this study, we use simulations from seven global vegetation models to provide the first multi-model estimate of fire impacts on global tree cover and the carbon cycle under current climate and anthropogenic land use conditions, averaged for the years 2001?2012. Fire globally reduces the tree covered area and vegetation carbon storage by 10{\%}. Regionally, the effects are much stronger, up to 20{\%} for certain latitudinal bands, and 17{\%} in savanna regions. Global fire effects on total carbon storage and carbon turnover times are lower with the effect on gross primary productivity (GPP) close to 0. We find the strongest impacts of fire in savanna regions. Climatic conditions in regions with the highest burned area differ from regions with highest absolute fire impact, which are characterized by higher precipitation. Our estimates of fire-induced vegetation change are lower than previous studies. We attribute these differences to different definitions of vegetation change and effects of anthropogenic land use, which were not considered in previous studies and decreases the impact of fire on tree cover. Accounting for fires significantly improves the spatial patterns of simulated tree cover, which demonstrates the need to represent fire in dynamic vegetation models. Based upon comparisons between models and observations, process understanding and representation in models, we assess a higher confidence in the fire impact on tree cover and vegetation carbon compared to GPP, total carbon storage and turnover times. We have higher confidence in the spatial patterns compared to the global totals of the simulated fire impact. As we used an ensemble of state-of-the-art fire models, including effects of land use and the ensemble median or mean compares better to observational datasets than any individual model, we consider the here presented results to be the current best estimate of global fire effects on ecosystems.},
annote = {doi: 10.1111/gcb.15160},
author = {Lasslop, Gitta and Hantson, Stijn and Harrison, Sandy P and Bachelet, Dominique and Burton, Chantelle and Forkel, Matthias and Forrest, Matthew and Li, Fang and Melton, Joe R and Yue, Chao and Archibald, Sally and Scheiter, Simon and Arneth, Almut and Hickler, Thomas and Sitch, Stephen},
doi = {10.1111/gcb.15160},
issn = {1354-1013},
journal = {Global Change Biology},
keywords = {global fire modelling,terrestrial carbon cycle,vegetation modelling,wildfires},
month = {sep},
number = {9},
pages = {5027--5041},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Global ecosystems and fire: Multi-model assessment of fire-induced tree-cover and carbon storage reduction}},
url = {https://doi.org/10.1111/gcb.15160},
volume = {26},
year = {2020}
}
@article{Lasslop2019,
abstract = {Purpose of Review: Understanding of how fire affects the carbon cycle and climate is crucial for climate change adaptation and mitigation strategies. As those are often based on Earth system model simulations, we identify recent progress and research needs that can improve the model representation of fire and its impacts. Recent Findings: New constraints of fire effects on the carbon cycle and climate are provided by the quantification of the carbon ages and effects of vegetation types and traits. For global scale modelling, the low understanding of the human–fire relationship is limiting. Summary: Recent developments allow improvements in Earth system models with respect to the influences of vegetation on climate, peatland burning and the pyrogenic carbon cycle. Better understanding of human influences is required. Given the impacts of fire on carbon storage and climate, thorough understanding of the effects of fire in the Earth system is crucial to support climate change mitigation and adaptation.},
author = {Lasslop, Gitta and Coppola, Alysha I. and Voulgarakis, Apostolos and Yue, Chao and Veraverbeke, Sander},
doi = {10.1007/s40641-019-00128-9},
issn = {21986061},
journal = {Current Climate Change Reports},
number = {2},
pages = {112--123},
title = {{Influence of Fire on the Carbon Cycle and Climate}},
volume = {5},
year = {2019}
}
@article{Lauerwald2019,
author = {Lauerwald, R. and Regnier, P. and Figueiredo, V. and Enrich‐Prast, A. and Bastviken, D. and Lehner, B. and Maavara, T. and Raymond, P.},
doi = {10.1029/2019GB006261},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
month = {dec},
number = {12},
pages = {1564--1581},
title = {{Natural Lakes Are a Minor Global Source of N2O to the Atmosphere}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GB006261},
volume = {33},
year = {2019}
}
@article{Lauerwald2015,
author = {Lauerwald, Ronny and Laruelle, Goulven G. and Hartmann, Jens and Ciais, Philippe and Regnier, Pierre A.G.},
doi = {10.1002/2014GB004941},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {may},
number = {5},
pages = {534--554},
title = {{Spatial patterns in CO2 evasion from the global river network}},
url = {http://doi.wiley.com/10.1002/2014GB004941},
volume = {29},
year = {2015}
}
@article{ISI:000365901800009,
abstract = {Abstract. Past model studies have projected a global decrease in marine net primary production (NPP) over the 21st century, but these studies focused on the multi-model mean rather than on the large inter-model differences. Here, we analyze model-simulated changes in NPP for the 21st century under IPCC's high-emission scenario RCP8.5. We use a suite of nine coupled carbon–climate Earth system models with embedded marine ecosystem models and focus on the spread between the different models and the underlying reasons. Globally, NPP decreases in five out of the nine models over the course of the 21st century, while three show no significant trend and one even simulates an increase. The largest model spread occurs in the low latitudes (between 30° S and 30° N), with individual models simulating relative changes between −25 and +40 {\%}. Of the seven models diagnosing a net decrease in NPP in the low latitudes, only three simulate this to be a consequence of the classical interpretation, i.e., a stronger nutrient limitation due to increased stratification leading to reduced phytoplankton growth. In the other four, warming-induced increases in phytoplankton growth outbalance the stronger nutrient limitation. However, temperature-driven increases in grazing and other loss processes cause a net decrease in phytoplankton biomass and reduce NPP despite higher growth rates. One model projects a strong increase in NPP in the low latitudes, caused by an intensification of the microbial loop, while NPP in the remaining model changes by less than 0.5 {\%}. While models consistently project increases NPP in the Southern Ocean, the regional inter-model range is also very substantial. In most models, this increase in NPP is driven by temperature, but it is also modulated by changes in light, macronutrients and iron as well as grazing. Overall, current projections of future changes in global marine NPP are subject to large uncertainties and necessitate a dedicated and sustained effort to improve the models and the concepts and data that guide their development.},
author = {Laufk{\"{o}}tter, C and Vogt, M and Gruber, N and Aita-Noguchi, M and Aumont, O and Bopp, L and Buitenhuis, E and Doney, S C and Dunne, J and Hashioka, T and Hauck, J and Hirata, T and John, J and {Le Qu{\'{e}}r{\'{e}}}, C. and Lima, I D and Nakano, H and Seferian, R and Totterdell, I and Vichi, M and V{\"{o}}lker, C.},
doi = {10.5194/bg-12-6955-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {dec},
number = {23},
pages = {6955--6984},
title = {{Drivers and uncertainties of future global marine primary production in marine ecosystem models}},
url = {https://www.biogeosciences.net/12/6955/2015/},
volume = {12},
year = {2015}
}
@article{Laufkotter2020,
author = {Laufk{\"{o}}tter, Charlotte and Zscheischler, Jakob and Fr{\"{o}}licher, Thomas},
doi = {10.1126/science.aba0690},
journal = {Science},
number = {6511},
pages = {1621--1625},
title = {{High-impact marine heatwaves attributable to human-induced global warming}},
volume = {369},
year = {2020}
}
@article{Laufkoetter2015,
abstract = {Past model studies have projected a global decrease in marine net primary production (NPP) over the 21st century, but these studies focused on the multi-model mean rather than on the large inter-model differences. Here, we analyze model-simulated changes in NPP for the 21st century under IPCC's high-emission scenario RCP8.5. We use a suite of nine coupled carbon-climate Earth system models with embedded marine ecosystem models and focus on the spread between the different models and the underlying reasons. Globally, NPP decreases in five out of the nine models over the course of the 21st century, while three show no significant trend and one even simulates an increase. The largest model spread occurs in the low latitudes (between 30 degrees S and 30 degrees N), with individual models simulating relative changes between -25 and +40 {\%}. Of the seven models diagnosing a net decrease in NPP in the low latitudes, only three simulate this to be a consequence of the classical interpretation, i.e., a stronger nutrient limitation due to increased stratification leading to reduced phytoplankton growth. In the other four, warming-induced increases in phytoplankton growth outbalance the stronger nutrient limitation. However, temperature-driven increases in grazing and other loss processes cause a net decrease in phytoplankton biomass and reduce NPP despite higher growth rates. One model projects a strong increase in NPP in the low latitudes, caused by an intensification of the microbial loop, while NPP in the remaining model changes by less than 0.5 {\%}. While models consistently project increases NPP in the Southern Ocean, the regional inter-model range is also very substantial. In most models, this increase in NPP is driven by temperature, but it is also modulated by changes in light, macronutrients and iron as well as grazing. Overall, current projections of future changes in global marine NPP are subject to large uncertainties and necessitate a dedicated and sustained effort to improve the models and the concepts and data that guide their development.},
author = {Laufkoetter, C and Vogt, M and Gruber, N and Aita-Noguchi, M and Aumont, O and Bopp, L and Buitenhuis, E and Doney, S C and Dunne, J and Hashioka, T and Hauck, J and Hirata, T and John, J and {Le Quere}, C and Lima, I D and Nakano, H and Seferian, R and Totterdell, I and Vichi, M and Voelker, C},
doi = {10.5194/bg-12-6955-2015},
issn = {1726-4170},
journal = {Biogeosciences},
number = {23},
pages = {6955--6984},
title = {{Drivers and uncertainties of future global marine primary production in marine ecosystem models}},
volume = {12},
year = {2015}
}
@article{Laurent2017,
abstract = {Abstract Nutrient inputs from the Mississippi/Atchafalaya River system into the northern Gulf of Mexico promote high phytoplankton production and lead to high respiration rates. Respiration coupled with water column stratification results in seasonal summer hypoxia in bottom waters on the shelf. In addition to consuming oxygen, respiration produces carbon dioxide (CO2), thus lowering the pH and acidifying bottom waters. Here we present a high-resolution biogeochemical model simulating this eutrophication-driven acidification and investigate the dominant underlying processes. The model shows the recurring development of an extended area of acidified bottom waters in summer on the northern Gulf of Mexico shelf that coincides with hypoxic waters. Not reported before, acidified waters are confined to a thin bottom boundary layer where the production of CO2 by benthic metabolic processes is dominant. Despite a reduced saturation state, acidified waters remain supersaturated with respect to aragonite.},
annote = {doi: 10.1002/2016GL071881},
author = {Laurent, Arnaud and Fennel, Katja and Cai, Wei-Jun and Huang, Wei-Jen and Barbero, Leticia and Wanninkhof, Rik},
doi = {10.1002/2016GL071881},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Mississippi,acidification,biogeochemical model,eutrophication,hypoxia,northern Gulf of Mexico},
month = {jan},
number = {2},
pages = {946--956},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Eutrophication-induced acidification of coastal waters in the northern Gulf of Mexico: Insights into origin and processes from a coupled physical–biogeochemical model}},
url = {https://doi.org/10.1002/2016GL071881 http://doi.wiley.com/10.1002/2016GL071881},
volume = {44},
year = {2017}
}
@article{Lauvset,
abstract = {Ocean acidification evolves on the background of a natural ocean pH variability that is the result of the interplay between ocean mixing, biological production and remineralization, calcium carbonate cycling, temperature and pressure changes across the water column. While previous studies have analyzed these processes and their impacts on ocean carbonate chemistry, none have attempted to quantify their impacts on interior ocean pH globally. Here we evaluate how anthropogenic changes and natural processes collectively act on ocean pH, and how these processes set the vulnerability of regions to future changes in ocean acidification. We use the mapped data product from the Global Ocean Data Analysis Project version 2 (GLODAPv2), a novel method to estimate preformed total alkalinity based on a combination of a total matrix intercomparison (TMI) and locally interpolated regressions (LIRs), and a comprehensive uncertainty analysis. We find the most important natural process is organic matter remineralization, with CaCO3 cycling being the second most important process. The estimates of the impact of anthropogenic CO2 changes on pH reaffirm the large and well understood anthropogenic impact on pH in the surface ocean, and put it in the context of natural pH distribution variability in the interior ocean. We also show that in some areas natural processes appear to enhance ocean acidification.},
author = {Lauvset, S. K. and Carter, B. R. and P{\`{e}}rez, F. F. and Jiang, L.‐Q. and Feely, R. A. and Velo, Anton and Olsen, Are},
doi = {10.1029/2019GB006229},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
month = {jan},
number = {1},
pages = {2019GB006229},
title = {{Processes Driving Global Interior Ocean pH Distribution}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2019GB006229},
volume = {34},
year = {2020}
}
@article{Lauvset2017a,
author = {Lauvset, S K and Tjiputra, J and Muri, H},
doi = {10.5194/bg-14-5675-2017},
journal = {Biogeosciences},
number = {24},
pages = {5675--5691},
title = {{Climate engineering and the ocean: effects on biogeochemistry and primary production}},
volume = {14},
year = {2017}
}
@article{Lauvset2015a,
abstract = {Abstract. We report global long-term trends in surface ocean pH using a new pH data set computed by combining fCO2 observations from the Surface Ocean CO2 Atlas (SOCAT) version 2 with surface alkalinity estimates based on temperature and salinity. Trends were determined over the periods 1981–2011 and 1991–2011 for a set of 17 biomes using a weighted linear least squares method. We observe significant decreases in surface ocean pH in {\~{}}70{\%} of all biomes and a mean rate of decrease of 0.0018 ± 0.0004 yr−1 for 1991–2011. We are not able to calculate a global trend for 1981–2011 because too few biomes have enough data for this. In half the biomes, the rate of change is commensurate with the trends expected based on the assumption that the surface ocean pH change is only driven by the surface ocean CO2 chemistry remaining in a transient equilibrium with the increase in atmospheric CO2. In the remaining biomes, deviations from such equilibrium may reflect that the trend of surface ocean fCO2 is not equal to that of the atmosphere, most notably in the equatorial Pacific Ocean, or may reflect changes in the oceanic buffer (Revelle) factor. We conclude that well-planned and long-term sustained observational networks are key to reliably document the ongoing and future changes in ocean carbon chemistry due to anthropogenic forcing.},
author = {Lauvset, S K and Gruber, N and Landsch{\"{u}}tzer, P and Olsen, A and Tjiputra, J},
doi = {10.5194/bg-12-1285-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {mar},
number = {5},
pages = {1285--1298},
title = {{Trends and drivers in global surface ocean pH over the past 3 decades}},
url = {https://www.biogeosciences.net/12/1285/2015/ https://bg.copernicus.org/articles/12/1285/2015/},
volume = {12},
year = {2015}
}
@article{Lavergne2019,
author = {Lavergne, Ali{\'{e}}nor and Graven, Heather and {De Kauwe}, Martin G. and Keenan, Trevor F. and Medlyn, Belinda E. and Prentice, Iain Colin},
doi = {10.1111/gcb.14634},
issn = {1354-1013},
journal = {Global Change Biology},
month = {jul},
number = {7},
pages = {2242--2257},
title = {{Observed and modelled historical trends in the water-use efficiency of plants and ecosystems}},
url = {https://onlinelibrary.wiley.com/doi/10.1111/gcb.14634},
volume = {25},
year = {2019}
}
@article{esd-8-1237-2017,
abstract = {Abstract. Tropical forests have been a permanent feature of the Amazon basin for at least 55 million years, yet climate change and land use threaten the forest's future over the next century. Understory forest fires, which are common under the current climate in frontier forests, may accelerate Amazon forest losses from climate-driven dieback and deforestation. Far from land use frontiers, scarce fire ignitions and high moisture levels preclude significant burning, yet projected climate and land use changes may increase fire activity in these remote regions. Here, we used a fire model specifically parameterized for Amazon understory fires to examine the interactions between anthropogenic activities and climate under current and projected conditions. In a scenario of low mitigation efforts with substantial land use expansion and climate change {\&}ndash; Representative Concentration Pathway (RCP) 8.5 {\&}ndash; projected understory fires increase in frequency and duration, burning 4{\&}ndash;28 times more forest in 2080{\&}ndash;2100 than during 1990{\&}ndash;2010. In contrast, active climate mitigation and land use contraction in RCP4.5 constrain the projected increase in fire activity to 0.9{\&}ndash;5.4 times contemporary burned area. Importantly, if climate mitigation is not successful, land use contraction alone is very effective under low to moderate climate change, but does little to reduce fire activity under the most severe climate projections. These results underscore the potential for a fire-driven transformation of Amazon forests if recent regional policies for forest conservation are not paired with global efforts to mitigate climate change.},
annote = {added by A.Eliseev 25.01.2019},
author = {{Le Page}, Yannick and Morton, Douglas and Hartin, Corinne and Bond-Lamberty, Ben and Pereira, Jos{\'{e}} Miguel Cardoso and Hurtt, George and Asrar, Ghassem},
doi = {10.5194/esd-8-1237-2017},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {dec},
number = {4},
pages = {1237--1246},
title = {{Synergy between land use and climate change increases future fire risk in Amazon forests}},
url = {https://www.earth-syst-dynam.net/8/1237/2017/},
volume = {8},
year = {2017}
}
@article{LeQuere2020,
abstract = {Government policies during the COVID-19 pandemic have drastically altered patterns of energy demand around the world. Many international borders were closed and populations were confined to their homes, which reduced transport and changed consumption patterns. Here we compile government policies and activity data to estimate the decrease in CO2 emissions during forced confinements. Daily global CO2 emissions decreased by –17{\%} (–11 to –25{\%} for ±1$\sigma$) by early April 2020 compared with the mean 2019 levels, just under half from changes in surface transport. At their peak, emissions in individual countries decreased by –26{\%} on average. The impact on 2020 annual emissions depends on the duration of the confinement, with a low estimate of –4{\%} (–2 to –7{\%}) if prepandemic conditions return by mid-June, and a high estimate of –7{\%} (–3 to –13{\%}) if some restrictions remain worldwide until the end of 2020. Government actions and economic incentives postcrisis will likely influence the global CO2 emissions path for decades.},
author = {{Le Qu{\'{e}}r{\'{e}}}, Corinne and Jackson, Robert B. and Jones, Matthew W. and Smith, Adam J.P. and Abernethy, Sam and Andrew, Robbie M. and De-Gol, Anthony J. and Willis, David R. and Shan, Yuli and Canadell, Josep G. and Friedlingstein, Pierre and Creutzig, Felix and Peters, Glen P.},
doi = {10.1038/s41558-020-0797-x},
isbn = {4155802007},
issn = {17586798},
journal = {Nature Climate Change},
number = {7},
pages = {647--653},
publisher = {Springer US},
title = {{Temporary reduction in daily global CO2 emissions during the COVID-19 forced confinement}},
url = {http://dx.doi.org/10.1038/s41558-020-0797-x},
volume = {10},
year = {2020}
}
@article{Quere2018,
abstract = {Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the global carbon budget – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. CO2 emissions from fossil fuels and industry (EFF) are based on energy statistics and cement production data, respectively, while emissions from land-use change (ELUC), mainly deforestation, are based on land-cover change data and bookkeeping models. The global atmospheric CO2 concentration is measured directly and its rate of growth (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) and terrestrial CO2 sink (SLAND) are estimated with global process models constrained by observations. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1$\sigma$. For the last decade available (2007–2016), EFF was 9.4 ± 0.5 GtC yr−1, ELUC 1.3 ± 0.7 GtC yr−1, GATM 4.7 ± 0.1 GtC yr−1, SOCEAN 2.4 ± 0.5 GtC yr−1, and SLAND 3.0 ± 0.8 GtC yr−1, with a budget imbalance BIM of 0.6 GtC yr−1 indicating overestimated emissions and/or underestimated sinks. For year 2016 alone, the growth in EFF was approximately zero and emissions remained at 9.9 ± 0.5 GtC yr−1. Also for 2016, ELUC was 1.3 ± 0.7 GtC yr−1, GATM was 6.1 ± 0.2 GtC yr−1, SOCEAN was 2.6 ± 0.5 GtC yr−1, and SLAND was 2.7 ± 1.0 GtC yr−1, with a small BIM of −0.3 GtC. GATM continued to be higher in 2016 compared to the past decade (2007–2016), reflecting in part the high fossil emissions and the small SLAND consistent with El Ni{\~{n}}o conditions. The global atmospheric CO2 concentration reached 402.8 ± 0.1 ppm averaged over 2016. For 2017, preliminary data for the first 6–9 months indicate a renewed growth in EFF of +2.0 {\%} (range of 0.8 to 3.0 {\%}) based on national emissions projections for China, USA, and India, and projections of gross domestic product (GDP) corrected for recent changes in the carbon intensity of the economy for the rest of the world. This living data update documents changes in the methods and data sets used in this new global carbon budget compared with previous publications of this data set (Le Qu{\'{e}}r{\'{e}} et al., 2016, 2015b, a, 2014, 2013). All results presented here can be downloaded from https://doi.org/10.18160/GCP-2017 (GCP, 2017).},
author = {{Le Qu{\'{e}}r{\'{e}}}, Corinne and Andrew, Robbie M. and Friedlingstein, Pierre and Sitch, Stephen and Pongratz, Julia and Manning, Andrew C. and Korsbakken, Jan Ivar and Peters, Glen P. and Canadell, Josep G. and Jackson, Robert B. and Boden, Thomas A. and Tans, Pieter P. and Andrews, Oliver D. and Arora, Vivek K. and Bakker, Dorothee C. E. and Barbero, Leticia and Becker, Meike and Betts, Richard A. and Bopp, Laurent and Chevallier, Fr{\'{e}}d{\'{e}}ric and Chini, Louise P. and Ciais, Philippe and Cosca, Catherine E. and Cross, Jessica and Currie, Kim and Gasser, Thomas and Harris, Ian and Hauck, Judith and Haverd, Vanessa and Houghton, Richard A. and Hunt, Christopher W. and Hurtt, George and Ilyina, Tatiana and Jain, Atul K. and Kato, Etsushi and Kautz, Markus and Keeling, Ralph F. and {Klein Goldewijk}, Kees and K{\"{o}}rtzinger, Arne and Landsch{\"{u}}tzer, Peter and Lef{\`{e}}vre, Nathalie and Lenton, Andrew and Lienert, Sebastian and Lima, Ivan and Lombardozzi, Danica and Metzl, Nicolas and Millero, Frank and Monteiro, Pedro M. S. and Munro, David R. and Nabel, Julia E. M. S. and Nakaoka, Shin-ichiro and Nojiri, Yukihiro and Padin, X. Antonio and Peregon, Anna and Pfeil, Benjamin and Pierrot, Denis and Poulter, Benjamin and Rehder, Gregor and Reimer, Janet and R{\"{o}}denbeck, Christian and Schwinger, J{\"{o}}rg and S{\'{e}}f{\'{e}}rian, Roland and Skjelvan, Ingunn and Stocker, Benjamin D. and Tian, Hanqin and Tilbrook, Bronte and Tubiello, Francesco N. and van der Laan-Luijkx, Ingrid T. and van der Werf, Guido R. and van Heuven, Steven and Viovy, Nicolas and Vuichard, Nicolas and Walker, Anthony P. and Watson, Andrew J. and Wiltshire, Andrew J. and Zaehle, S{\"{o}}nke and Zhu, Dan},
doi = {10.5194/essd-10-405-2018},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {mar},
number = {1},
pages = {405--448},
title = {{Global Carbon Budget 2017}},
url = {https://doi.org/10.5194/essd-10-405-2018 https://www.earth-syst-sci-data.net/10/405/2018/ https://essd.copernicus.org/articles/10/405/2018/},
volume = {10},
year = {2018}
}
@article{LeQuere2018c,
abstract = {Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFF) are based on energy statistics and cement production data, while emissions from land use and land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) and terrestrial CO2 sink (SLAND) are estimated with global process models constrained by observations. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1$\sigma$. For the last decade available (2008–2017), EFF was 9.4±0.5GtCyr−1, ELUC 1.5±0.7GtCyr−1, GATM 4.7±0.02GtCyr−1, SOCEAN 2.4±0.5GtCyr−1, and SLAND 3.2±0.8GtCyr−1, with a budget imbalance BIM of 0.5GtCyr−1 indicating overestimated emissions and/or underestimated sinks. For the year 2017 alone, the growth in EFF was about 1.6{\%} and emissions increased to 9.9±0.5GtCyr−1. Also for 2017, ELUC was 1.4±0.7GtCyr−1, GATM was 4.6±0.2GtCyr−1, SOCEAN was 2.5±0.5GtCyr−1, and SLAND was 3.8±0.8GtCyr−1, with a BIM of 0.3GtC. The global atmospheric CO2 concentration reached 405.0±0.1ppm averaged over 2017. For 2018, preliminary data for the first 6–9 months indicate a renewed growth in EFF of +2.7{\%} (range of 1.8{\%} to 3.7{\%}) based on national emission projections for China, the US, the EU, and India and projections of gross domestic product corrected for recent changes in the carbon intensity of the economy for the rest of the world. The analysis presented here shows that the mean and trend in the five components of the global carbon budget are consistently estimated over the period of 1959–2017, but discrepancies of up to 1GtCyr−1 persist for the representation of semi-decadal variability in CO2 fluxes. A detailed comparison among individual estimates and the introduction of a broad range of observations show (1) no consensus in the mean and trend in land-use change emissions, (2) a persistent low agreement among the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) an apparent underestimation of the CO2 variability by ocean models, originating outside the tropics. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding the global carbon cycle compared with previous publications of this data set (Le Qu{\'{e}}r{\'{e}} et al., 2018, 2016, 2015a, b, 2014, 2013). All results presented here can be downloaded from https://doi.org/10.18160/GCP-2018. ]]{\textgreater}},
author = {{Le Qu{\'{e}}r{\'{e}}}, Corinne and Andrew, Robbie M. and Friedlingstein, Pierre and Sitch, Stephen and Hauck, Judith and Pongratz, Julia and Pickers, Penelope A. and Korsbakken, Jan Ivar and Peters, Glen P. and Canadell, Josep G. and Arneth, Almut and Arora, Vivek K. and Barbero, Leticia and Bastos, Ana and Bopp, Laurent and Chevallier, Fr{\'{e}}d{\'{e}}ric and Chini, Louise P. and Ciais, Philippe and Doney, Scott C. and Gkritzalis, Thanos and Goll, Daniel S. and Harris, Ian and Haverd, Vanessa and Hoffman, Forrest M. and Hoppema, Mario and Houghton, Richard A. and Hurtt, George and Ilyina, Tatiana and Jain, Atul K. and Johannessen, Truls and Jones, Chris D. and Kato, Etsushi and Keeling, Ralph F. and Goldewijk, Kees Klein and Landsch{\"{u}}tzer, Peter and Lef{\`{e}}vre, Nathalie and Lienert, Sebastian and Liu, Zhu and Lombardozzi, Danica and Metzl, Nicolas and Munro, David R. and Nabel, Julia E. M. S. and Nakaoka, Shin-ichiro and Neill, Craig and Olsen, Are and Ono, Tsueno and Patra, Prabir and Peregon, Anna and Peters, Wouter and Peylin, Philippe and Pfeil, Benjamin and Pierrot, Denis and Poulter, Benjamin and Rehder, Gregor and Resplandy, Laure and Robertson, Eddy and Rocher, Matthias and R{\"{o}}denbeck, Christian and Schuster, Ute and Schwinger, J{\"{o}}rg and S{\'{e}}f{\'{e}}rian, Roland and Skjelvan, Ingunn and Steinhoff, Tobias and Sutton, Adrienne and Tans, Pieter P. and Tian, Hanqin and Tilbrook, Bronte and Tubiello, Francesco N. and van der Laan-Luijkx, Ingrid T. and van der Werf, Guido R. and Viovy, Nicolas and Walker, Anthony P. and Wiltshire, Andrew J. and Wright, Rebecca and Zaehle, S{\"{o}}nke and Zheng, Bo},
doi = {10.5194/essd-10-2141-2018},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {dec},
number = {4},
pages = {2141--2194},
title = {{Global Carbon Budget 2018}},
url = {https://www.earth-syst-sci-data-discuss.net/essd-2018-120/ https://www.earth-syst-sci-data.net/10/2141/2018/ https://essd.copernicus.org/articles/10/2141/2018/},
volume = {10},
year = {2018}
}
@article{leduc15,
author = {Leduc, Martin and Matthews, H Damon and de El{\'{i}}a, Ram{\'{o}}n},
doi = {10.1175/JCLI-D-14-00500.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {dec},
number = {24},
pages = {9955--9968},
title = {{Quantifying the limits of a linear temperature response to cumulative CO2 emissions}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-14-00500.1},
volume = {28},
year = {2015}
}
@article{Leduc2016a,
abstract = {An analysis of the regional climate response to cumulative CO2 emissions establishes a clear quantitative link between the total amount of CO2 emitted and the magnitude of local climate warming.},
author = {Leduc, Martin and Matthews, H. Damon and de El{\'{i}}a, Ram{\'{o}}n},
doi = {10.1038/nclimate2913},
issn = {1758-678X},
journal = {Nature Climate Change},
keywords = {Climate and Earth system modelling,Projection and prediction},
month = {may},
number = {5},
pages = {474--478},
publisher = {Nature Publishing Group},
title = {{Regional estimates of the transient climate response to cumulative CO2 emissions}},
url = {http://www.nature.com/articles/nclimate2913},
volume = {6},
year = {2016}
}
@article{Lee2011,
abstract = {The number of clean development mechanism (CDM) projects aimed at reducing N2O emissions has increased in recent years. While N2O reduction projects account for only 2.6{\%} of all CDM projects, these N2O reduction projects account for 13{\%} of the total reduction of all greenhouse gases measured on a CO2 equivalent basis under the CDM. China is the host nation for half of all N2O CDM reduction projects while approximately 78{\%} of the N2O reduction technologies for these CDM projects come from Japan, the UK, and Switzerland. This paper consists of an investigation of the present status of and prospects for CDM projects to reduce N2O emissions based on the data of the United Nations Framework Convention on Climate Change (UNFCCC). N2O reduction in CDM projects has been applied to production plants for such chemicals as nitric acid, adipic acid, and caprolactam. The technologies for N2O reduction used in these CDM projects were thermal or catalytic decomposition and selective catalytic reduction with the selection of a specific reduction strategy dependent upon the underlying production process. This paper presents case studies which examine the application of specific N2O reduction technologies that have been implemented under the CDM. The CDM market for N2O reductions from the industrial sector is nearing saturation and therefore further growth will likely be dependent upon technological progress and the ability to deploy N2O reduction technologies with combustion based stationary sources and mobile sources. A particular focus of technological development efforts should be cost effectiveness and development of technologies that can simultaneously reduce N2O and NOx emissions.},
author = {Lee, Seung-Jae and Ryu, In-Soo and Kim, Byung-Moon and Moon, Seung-Hyun},
doi = {10.1016/j.ijggc.2010.07.001},
issn = {17505836},
journal = {International Journal of Greenhouse Gas Control},
month = {jan},
number = {1},
pages = {167--176},
publisher = {Elsevier},
title = {{A review of the current application of N2O emission reduction in CDM projects}},
url = {https://www.sciencedirect.com/science/article/pii/S1750583610001131?via{\%}3Dihub https://linkinghub.elsevier.com/retrieve/pii/S1750583610001131},
volume = {5},
year = {2011}
}
@article{Lee2019a,
abstract = {Abstract Climate engineering arises as one of the potential methods that could contribute to meeting the 1.5 °C global warming target agreed under the Paris Agreement. We examine how permafrost and high-latitude vegetation respond to the large-scale implementation of climate engineering. Specifically, we explore the impacts of applying the solar radiation management method of stratospheric aerosol injections (SAI) on permafrost temperature and the global extent of near-surface permafrost area. We compare the RCP8.5 and RCP4.5 scenarios to several SAI deployment scenarios using the Norwegian Earth System Model (CE1 = moderate SAI scenario to bring down the global mean warming in RCP8.5 to the RCP4.5 level, CE2 = aggresive SAI scenario to maintain the global mean temperature toward the preindustrial level). We show that large-scale application of SAI may help slow down the current rate of permafrost degradation for a wide range of emission scenarios. Between the RCP4.5 and CE1 simulations, the differences in the permafrost degradation may be attributed to the spatial variations in surface air temperature, rainfall, and snowfall, which lead to the differences in the timing of permafrost degradation up to 40 years. Although atmospheric temperatures in CE1 and RCP4.5 simulations are similar, net primary production is higher in CE1 due to CO2 fertilization. Our investigation of permafrost extent under large-scale SAI application scenarios suggests that circum-Arctic permafrost area and extent is rather sensitive to temperature changes created under such SAI application. Our results highlight the importance of investigating the regional effects of climate engineering, particularly in high-latitude ecosystems.},
author = {Lee, Hanna and Ekici, Altug and Tjiputra, Jerry and Muri, Helene and Chadburn, Sarah E and Lawrence, David M and Schwinger, J{\"{o}}rg},
doi = {10.1029/2018EF001146},
journal = {Earth's Future},
number = {6},
pages = {605--614},
title = {{The Response of Permafrost and High-Latitude Ecosystems Under Large-Scale Stratospheric Aerosol Injection and Its Termination}},
volume = {7},
year = {2019}
}
@article{Legendre2015,
author = {Legendre, Louis and Rivkin, Richard B. and Weinbauer, Markus G. and Guidi, Lionel and Uitz, Julia},
doi = {10.1016/j.pocean.2015.01.008},
issn = {00796611},
journal = {Progress in Oceanography},
month = {may},
pages = {432--450},
title = {{The microbial carbon pump concept: Potential biogeochemical significance in the globally changing ocean}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0079661115000105},
volume = {134},
year = {2015}
}
@incollection{Lehmann2015,
address = {London, UK},
author = {Lehmann, Johannes and Abiven, Samuel and Kleber, Markus and Pan, Genxing and Singh, Bhupinder Pal and Sohi, Saran and Zimmermann, Andrew and Lehmann, Jascha and Joseph, Stephen},
booktitle = {Biochar for Environmental Management: Science, Technology and Implementation (Second Edition)},
doi = {10.4324/9780203762264},
editor = {Lehmann, Johannes and Joseph, Stephen},
pages = {233----80},
publisher = {Routledge},
title = {{Persistence of biochar in soil}},
volume = {2},
year = {2015}
}
@article{Lehmann2014,
abstract = {Savannas are structurally similar across the three major continents where they occur, leading to the assumption that the factors controlling vegetation structure and function are broadly similar, too. Lehmann et al. (p. 548) report the results of an extensive analysis of ground-based tree abundance in savannas, sampled at more than 2000 sites in Africa, Australia, and South America. All savannas, independent of region, shared a common functional property in the way that moisture and fire regulated tree abundance. However, despite qualitative similarity in the moisture–fire–tree-biomass relationships among continents, key quantitative differences exist among the three regions, presumably as a result of unique evolutionary histories and climatic domains. Ecologists have long sought to understand the factors controlling the structure of savanna vegetation. Using data from 2154 sites in savannas across Africa, Australia, and South America, we found that increasing moisture availability drives increases in fire and tree basal area, whereas fire reduces tree basal area. However, among continents, the magnitude of these effects varied substantially, so that a single model cannot adequately represent savanna woody biomass across these regions. Historical and environmental differences drive the regional variation in the functional relationships between woody vegetation, fire, and climate. These same differences will determine the regional responses of vegetation to future climates, with implications for global carbon stocks.},
author = {Lehmann, Caroline E R and Anderson, T Michael and Sankaran, Mahesh and Higgins, Steven I and Archibald, Sally and Hoffmann, William A and Hanan, Niall P and Williams, Richard J and Fensham, Roderick J and Felfili, Jeanine and Hutley, Lindsay B and Ratnam, Jayashree and {San Jose}, Jose and Montes, Ruben and Franklin, Don and Russell-Smith, Jeremy and Ryan, Casey M and Durigan, Giselda and Hiernaux, Pierre and Haidar, Ricardo and Bowman, David M J S and Bond, William J},
doi = {10.1126/science.1247355},
journal = {Science},
month = {jan},
number = {6170},
pages = {548--552},
title = {{Savanna Vegetation–Fire–Climate Relationships Differ Among Continents}},
url = {http://science.sciencemag.org/content/343/6170/548.abstract},
volume = {343},
year = {2014}
}
@article{Leifeld2019,
abstract = {Land-use change disturbs the function of peatland as a natural carbon sink and triggers high GHG emissions1. Nevertheless, historical trends and future trajectories of GHG budgets from soil do not explicitly include peatlands2,3. Here, we provide an estimate of the past and future role of global peatlands as either a source or sink of GHGs based on scenario timelines of land conversion. Between 1850 and 2015, temperate and boreal regions lost 26.7 million ha, and tropical regions 24.7 million ha, of natural peatland. By 2100, peatland conversion in tropical regions might increase to 36.3 million ha. Cumulative emissions from drained sites reached 80 ± 20 PgCO2e in 2015 and will add up to 249 ± 38 Pg by 2100. At the same time, the number of intact sites accumulating peat will decline. In 1960 the global peatland biome turned from a net sink into a net source of soil-derived GHGs. Annual back-conversion of most of the drained area would render peatlands GHG neutral, whereas emissions from peatland may comprise 12–41{\%} of the GHG emission budget for keeping global warming below +1.5 to +2 °C without rehabilitation.},
author = {Leifeld, Jens and W{\"{u}}st-Galley, Chlo{\'{e}} and Page, Susan},
doi = {10.1038/s41558-019-0615-5},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {12},
pages = {945--947},
title = {{Intact and managed peatland soils as a source and sink of GHGs from 1850 to 2100}},
volume = {9},
year = {2019}
}
@article{Lemordant2018,
abstract = {Predicting how increasing atmospheric CO2 will affect the hydrologic cycle is of utmost importance for a range of applications ranging from ecological services to human life and activities. A typical perspective is that hydrologic change is driven by precipitation and radiation changes due to climate change, and that the land surface will adjust. Using Earth system models with decoupled surface (vegetation physiology) and atmospheric (radiative) CO2 responses, we here show that the CO2 physiological response has a dominant role in evapotranspiration and evaporative fraction changes and has a major effect on long-term runoff compared with radiative or precipitation changes due to increased atmospheric CO2. This major effect is true for most hydrological stress variables over the largest fraction of the globe, except for soil moisture, which exhibits a more nonlinear response. This highlights the key role of vegetation in controlling future terrestrial hydrologic response and emphasizes that the carbon and water cycles are intimately coupled over land.},
author = {Lemordant, L{\'{e}}o and Gentine, Pierre and Swann, Abigail S. and Cook, Benjamin I. and Scheff, Jacob},
doi = {10.1073/pnas.1720712115},
isbn = {1720712115},
issn = {10916490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Climate change,Coupling,Hydrology,Land–atmosphere,Vegetation physiology,Water cycle},
number = {16},
pages = {4093--4098},
pmid = {29610293},
title = {{Critical impact of vegetation physiology on the continental hydrologic cycle in response to increasing CO2}},
volume = {115},
year = {2018}
}
@article{Lencina-Avila2018,
abstract = {It is arduous to gather a good spatial and temporal dataset of marine carbonate properties, especially in the Southern Ocean. In this study, we have reconstructed the carbonate system in the Gerlache Strait, a coastal zone of the Northern Antarctic Peninsula. We also analyzed the impact of ocean acidification by calculating the tipping points of the calcium carbonate saturation states and pH (i.e., when saturation state and pH goes below one and 7, respectively). Hydrographic and carbonate data from three distinct data sets (GOAL - 2013-2016, FRUELA 1996, and World Ocean Database - 1965-2004) have been joined and used to reconstruct the carbonate system from the past 50 years. Temporal annual mean trends were determined depending on the water column depth-layer. The northern Gerlache Strait showed a significant increasing trend of total inorganic carbon concentrations (1.0024 +/- 0.34 mu mol kg(-1)) and related pH decreasing trend (-0.0026 +/- 0.0009 sws) in the surface mixed layer ({\textgreater} 60 m). The properties variability is relatively different (magnitudes and signs) between the northern and southern sectors of the Gerlache Strait, which indicate that adjacent regions to the Gerlache Strait to the southwest and north, respectively, may major influence the regional carbonate dynamics. Results also show that episodic under-saturation conditions, in relation to aragonite within the surface mixed layer, may already occur, especially in regions close to large glaciers.},
author = {Lencina-Avila, Jannine M and Goyet, Catherine and Kerr, Rodrigo and Orselli, Iole B.M. and Mata, Mauricio M and Touratier, Franck},
doi = {10.1016/j.dsr2.2017.10.018},
issn = {09670645},
journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
month = {mar},
number = {SI},
pages = {193--205},
title = {{Past and future evolution of the marine carbonate system in a coastal zone of the Northern Antarctic Peninsula}},
volume = {149},
year = {2018}
}
@article{Lennartz2014a,
abstract = {Abstract. The Boknis Eck (BE) time series station, initiated in 1957, is one of the longest-operated time series stations worldwide. We present the first statistical evaluation of a data set of nine physical, chemical and biological parameters in the period of 1957–2013. In the past three to five decades, all of the measured parameters underwent significant long-term changes. Most striking is an ongoing decline in bottom water oxygen concentration, despite a significant decrease of nutrient and chlorophyll a concentrations. Temperature-enhanced oxygen consumption in the bottom water and a prolongation of the stratification period are discussed as possible reasons for the ongoing oxygen decline despite declining eutrophication. Observations at the BE station were compared with model output of the Kiel Baltic Sea Ice Ocean Model (BSIOM). Reproduced trends were in good agreement with observed trends for temperature and oxygen, but generally the oxygen concentration at the bottom has been overestimated.},
author = {Lennartz, S T and Lehmann, A and Herrford, J and Malien, F and Hansen, H.-P. and Biester, H and Bange, H W},
doi = {10.5194/bg-11-6323-2014},
issn = {1726-4189},
journal = {Biogeosciences},
month = {nov},
number = {22},
pages = {6323--6339},
title = {{Long-term trends at the Boknis Eck time series station (Baltic Sea), 1957–2013: does climate change counteract the decline in eutrophication?}},
volume = {11},
year = {2014}
}
@article{Lenton2008,
abstract = {The term ‘‘tipping point'' commonly refers to a critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system. Here we introduce the term ‘‘tipping element'' to describe large-scale components of the Earth system that may pass a tipping point. We critically evaluate potential policy-relevant tipping elements in the climate system under anthropogenic forcing, drawing on the pertinent literature and a recent international workshop to compile a short list, and we assess where their tipping points lie. An expert elicitation is used to help rank their sensitivity to global warming and the uncertainty about the underlying physical mechanisms. Then we explain how, in principle, early warning systems could be established to detect the proximity of some tipping points.},
author = {Lenton, T. M. and Held, H. and Kriegler, E. and Hall, J. W. and Lucht, W. and Rahmstorf, S. and Schellnhuber, H. J.},
doi = {10.1073/pnas.0705414105},
isbn = {1091-6490 (Electronic) 0027-8424 (Linking)},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {feb},
number = {6},
pages = {1786--1793},
pmid = {18258748},
title = {{Tipping elements in the Earth's climate system}},
url = {http://www.pnas.org/content/105/6/1786 http://www.pnas.org/cgi/doi/10.1073/pnas.0705414105},
volume = {105},
year = {2008}
}
@article{Leung2020,
author = {Leung, Shirley W. and Weber, Thomas and Cram, Jacob A. and Deutsch, Curtis},
doi = {10.5194/bg-18-229-2021},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jan},
number = {1},
pages = {229--250},
title = {{Variable particle size distributions reduce the sensitivity of global export flux to climate change}},
url = {https://bg.copernicus.org/articles/18/229/2021/},
volume = {18},
year = {2021}
}
@article{Leutert2020,
abstract = {The middle Miocene climate transition ({\~{}}14 million years ago) was characterized by a dramatic increase in the volume of the Antarctic ice sheet. The driving mechanism of this transition remains under discussion, with hypotheses including circulation changes, declining carbon dioxide in the atmosphere and orbital forcing. Southern Ocean records of planktic foraminiferal Mg/Ca have previously been interpreted to indicate a cooling of 6–7 °C and a decrease in salinity that preceded Antarctic cryosphere expansion by up to {\~{}}300,000 years. This interpretation has led to the hypothesis that changes in meridional heat and vapour transport along with an early thermal isolation of Antarctica from extrapolar climates played a fundamental role in triggering ice growth. Here we revisit the middle Miocene Southern Ocean temperature evolution using clumped isotope and lipid biomarker temperature proxies. Our records indicate that the Southern Ocean cooling and the associated salinity decrease occurred in phase with the expansion of the Antarctic ice sheet. We demonstrate that the timing and magnitude of the Southern Ocean temperature change seen in previous reconstructions can be explained if we consider pH as an additional, non-thermal, control on foraminiferal Mg/Ca ratios. Therefore, our new dataset challenges the view of a thermal isolation of Antarctica preceding ice sheet expansion, and suggests a strong coupling between Southern Ocean conditions and Antarctic ice volume in times of declining atmospheric carbon dioxide.},
author = {Leutert, Thomas J. and Auderset, Alexandra and Mart{\'{i}}nez-Garc{\'{i}}a, Alfredo and Modestou, Sevasti and Meckler, A. Nele},
doi = {10.1038/s41561-020-0623-0},
issn = {17520908},
journal = {Nature Geoscience},
number = {9},
pages = {634--639},
title = {{Coupled Southern Ocean cooling and Antarctic ice sheet expansion during the middle Miocene}},
volume = {13},
year = {2020}
}
@article{doi:10.1111/j.1600-0889.2009.00446.x,
abstract = {ABSTRACT Global high-precision atmospheric $\Delta$14CO2 records covering the last two decades are presented, and evaluated in terms of changing (radio)carbon sources and sinks, using the coarse-grid carbon cycle model GRACE. Dedicated simulations of global trends and interhemispheric differences with respect to atmospheric CO2 as well as $\delta$13CO2 and $\Delta$14CO2, are shown to be in good agreement with the available observations (1940–2008). While until the 1990s the decreasing trend of $\Delta$14CO2 was governed by equilibration of the atmospheric bomb 14C perturbation with the oceans and terrestrial biosphere, the largest perturbation today are emissions of 14C-free fossil fuel CO2. This source presently depletes global atmospheric $\Delta$14CO2 by 12–14‰ yr−1, which is partially compensated by 14CO2 release from the biosphere, industrial 14C emissions and natural 14C production. Fossil fuel emissions also drive the changing north–south gradient, showing lower $\Delta$14C in the northern hemisphere only since 2002. The fossil fuel-induced north–south (and also troposphere–stratosphere) $\Delta$14CO2 gradient today also drives the tropospheric $\Delta$14CO2 seasonality through variations of air mass exchange between these atmospheric compartments. Neither the observed temporal trend nor the $\Delta$14CO2 north–south gradient may constrain global fossil fuel CO2 emissions to better than 25{\%}, due to large uncertainties in other components of the (radio)carbon cycle.},
author = {Levin, Ingeborg and Naegler, Tobias and Kromer, Bernd and Diehl, Moritz and Francey, Roger and Gomez-Pelaez, Angel and Steele, Paul and Wagenbach, Dietmar and Weller, Rolf and Worthy, Douglas},
doi = {10.1111/j.1600-0889.2009.00446.x},
issn = {1600-0889},
journal = {Tellus B: Chemical and Physical Meteorology},
month = {jan},
number = {1},
pages = {26--46},
title = {{Observations and modelling of the global distribution and long-term trend of atmospheric 14CO2}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0889.2009.00446.x https://www.tandfonline.com/doi/full/10.1111/j.1600-0889.2009.00446.x},
volume = {62},
year = {2010}
}
@article{Levin2015,
abstract = {Accelerated oxygen loss in both coastal and open oceans is generating complex biological responses; future understanding and management will require holistic integration of currently fragmented oxygen observation and research programmes.},
author = {Levin, Lisa A. and Breitburg, Denise L.},
doi = {10.1038/nclimate2595},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {may},
number = {5},
pages = {401--403},
publisher = {Nature Publishing Group},
title = {{Linking coasts and seas to address ocean deoxygenation}},
volume = {5},
year = {2015}
}
@article{Levin2015b,
abstract = {The oceans' continental margins face strong and rapid change, forced by a combination of direct human activity, anthropogenic CO2-induced climate change, and natural variability. Stimulated by discussions in Goa, India at the IMBER IMBIZO III, we (1) provide an overview of the drivers of biogeochemical variation and change on margins, (2) compare temporal trends in hydrographic and biogeochemical data across different margins, (3) review ecosystem responses to these changes, (4) highlight the importance of margin time series for detecting and attributing change and (5) examine societal responses to changing margin biogeochemistry and ecosystems. We synthesize information over a wide range of margin settings in order to identify the commonalities and distinctions among continental margin ecosystems. Key drivers of biogeochemical variation include long-term climate cycles, CO2-induced warming, acidification, and deoxygenation, as well as sea level rise, eutrophication, hydrologic and water cycle alteration, changing land use, fishing, and species invasion. Ecosystem responses are complex and impact major margin services. These include primary production, fisheries production, nutrient cycling, shoreline protection, chemical buffering, and biodiversity. Despite regional differences, the societal consequences of these changes are unarguably large and mandate coherent actions to reduce, mitigate and adapt to multiple stressors on continental margins.},
author = {Levin, Lisa A and Liu, Kon-Kee and Emeis, Kay-Christian and Breitburg, Denise L and Cloern, James and Deutsch, Curtis and Giani, Michele and Goffart, Anne and Hofmann, Eileen E and Lachkar, Zouhair and Limburg, Karin and Liu, Su-Mei and Montes, Enrique and Naqvi, Wajih and Ragueneau, Olivier and Rabouille, Christophe and Sarkar, Santosh Kumar and Swaney, Dennis P and Wassman, Paul and Wishner, Karen F},
doi = {https://doi.org/10.1016/j.jmarsys.2014.04.016},
issn = {0924-7963},
journal = {Journal of Marine Systems},
pages = {3--17},
title = {{Comparative biogeochemistry–ecosystem–human interactions on dynamic continental margins}},
volume = {141},
year = {2015}
}
@article{Levin2018,
abstract = {Oxygen loss in the ocean, termed deoxygenation, is a major consequence of climate change and is exacerbated by other aspects of global change. An average global loss of 2{\%} or more has been recorded in the open ocean over the past 50?100 years, but with greater oxygen declines in intermediate waters (100?600 m) of the North Pacific, the East Pacific, tropical waters, and the Southern Ocean. Although ocean warming contributions to oxygen declines through a reduction in oxygen solubility and stratification effects on ventilation are reasonably well understood, it has been a major challenge to identify drivers and modifying factors that explain different regional patterns, especially in the tropical oceans. Changes in respiration, circulation (including upwelling), nutrient inputs, and possibly methane release contribute to oxygen loss, often indirectly through stimulation of biological production and biological consumption. Microbes mediate many feedbacks in oxygen minimum zones that can either exacerbate or ameliorate deoxygenation via interacting nitrogen, sulfur, and carbon cycles. The paleo-record reflects drivers of and feedbacks to deoxygenation that have played out through the Phanerozoic on centennial, millennial, and hundred-million-year timescales. Natural oxygen variability has made it difficult to detect the emergence of a climate-forced signal of oxygen loss, but new modeling efforts now project emergence to occur in many areas in 15?25 years. Continued global deoxygenation is projected for the next 100 or more years under most emissions scenarios, but with regional heterogeneity. Notably, even small changes in oxygenation can have significant biological effects. New efforts to systematically observe oxygen changes throughout the open ocean are needed to help address gaps in understanding of ocean deoxygenation patterns and drivers.},
annote = {doi: 10.1146/annurev-marine-121916-063359},
author = {Levin, Lisa A},
doi = {10.1146/annurev-marine-121916-063359},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {229--260},
publisher = {Annual Reviews},
title = {{Manifestation, Drivers, and Emergence of Open Ocean Deoxygenation}},
url = {https://doi.org/10.1146/annurev-marine-121916-063359 http://www.annualreviews.org/doi/10.1146/annurev-marine-121916-063359},
volume = {10},
year = {2018}
}
@article{Levine:2016,
abstract = {Amazon forests, which store ∼50{\%} of tropical forest carbon and play a vital role in global water, energy, and carbon cycling, are predicted to experience both longer and more intense dry seasons by the end of the 21st century. However, the climate sensitivity of this ecosystem remains uncertain: several studies have predicted large-scale die-back of the Amazon, whereas several more recent studies predict that the biome will remain largely intact. Combining remote-sensing and ground-based observations with a size- and age-structured terrestrial ecosystem model, we explore the sensitivity and ecological resilience of these forests to changes in climate. We demonstrate that water stress operating at the scale of individual plants, combined with spatial variation in soil texture, explains observed patterns of variation in ecosystem biomass, composition, and dynamics across the region, and strongly influences the ecosystem's resilience to changes in dry season length. Specifically, our analysis suggests that in contrast to existing predictions of either stability or catastrophic biomass loss, the Amazon forest's response to a drying regional climate is likely to be an immediate, graded, heterogeneous transition from high-biomass moist forests to transitional dry forests and woody savannah-like states. Fire, logging, and other anthropogenic disturbances may, however, exacerbate these climate change-induced ecosystem transitions.},
author = {Levine, Naomi M and Zhang, Ke and Longo, Marcos and Baccini, Alessandro and Phillips, Oliver L and Lewis, Simon L and Alvarez-D{\'{a}}vila, Esteban and {Segalin de Andrade}, Ana Cristina and Brienen, Roel J W and Erwin, Terry L and Feldpausch, Ted R and {Monteagudo Mendoza}, Abel Lorenzo and {Nu{\~{n}}ez Vargas}, Percy and Prieto, Adriana and Silva-Espejo, Javier Eduardo and Malhi, Yadvinder and Moorcroft, Paul R},
doi = {10.1073/pnas.1511344112},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {jan},
number = {3},
pages = {793--797},
title = {{Ecosystem heterogeneity determines the ecological resilience of the Amazon to climate change}},
url = {http://www.pnas.org/content/113/3/793.abstract http://www.pnas.org/lookup/doi/10.1073/pnas.1511344112},
volume = {113},
year = {2016}
}
@article{Levy2013,
abstract = {Although they are key components of the surface ocean carbon budget, physical processes inducing carbon fluxes across the mixed-layer base, i.e., subduction and obduction, have received much less attention than biological processes. Using a global model analysis of the preindustrial ocean, physical carbon fluxes are quantified and compared to the other carbon fluxes in and out of the surface mixed layer, i.e., air-sea CO2gas exchange and sedimentation of biogenic material. Model-based carbon obduction and subduction are evaluated against independent data-based estimates to the extent that was possible. We find that climatological physical fluxes of dissolved inorganic carbon (DIC) are two orders of magnitude larger than the other carbon fluxes and vary over the globe at smaller spatial scale. At temperate latitudes, the subduction of DIC and to a much lesser extent ({\textless}10{\%}) the sinking of particles maintain CO2undersaturation, whereas DIC is obducted back to the surface in the tropical band (75{\%}) and Southern Ocean (25{\%}). At the global scale, these two large counter-balancing fluxes of DIC amount to +275.5 PgC yr-1 for the supply by obduction and -264.5 PgC yr-1 for the removal by subduction which is ∼ 3 to 5 times larger than previous estimates. Moreover, we find that subduction of organic carbon (dissolved and particulate) represents ∼ 20{\%} of the total export of organic carbon: at the global scale, we evaluate that of the 11 PgC yr-1 of organic material lost from the surface every year, 2.1 PgC yr-1 is lost through subduction of organic carbon. Our results emphasize the strong sensitivity of the oceanic carbon cycle to changes in mixed-layer depth, ocean currents, and wind. Key Points Global physical DIC fluxes across the mixed-layer are +275/ -264 PgC/yr DIC physical fluxes are 50-100 times larger than sedimentation and CO2 flux Organic C physical flux is 30{\%} of total organic C export from the surface {\textcopyright}2013. American Geophysical Union. All Rights Reserved.},
author = {Levy, M. and Bopp, L. and Karleskind, P. and Resplandy, L. and Ethe, C. and Pinsard, F.},
doi = {10.1002/gbc.20092},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {biogeochemical model,carbon pumps,mixed-layer carbon budget,preindustrial ocean,subduction/obduction},
number = {4},
pages = {1001--1012},
title = {{Physical pathways for carbon transfers between the surface mixed layer and the ocean interior}},
volume = {27},
year = {2013}
}
@article{Lewis2019,
author = {Lewis, Simon L. and Wheeler, Charlotte E. and Mitchard, Edward T. A. and Koch, Alexander},
doi = {10.1038/d41586-019-01026-8},
issn = {0028-0836},
journal = {Nature},
keywords = {Climate change,Environmental sciences,Policy},
number = {7750},
pages = {25--28},
title = {{Regenerate natural forest to store carbon}},
url = {http://www.nature.com/articles/d41586-019-01026-8},
volume = {568},
year = {2019}
}
@article{Li2016c,
abstract = {Conventional calculations of the global carbon budget infer the land sink as a residual between emissions, atmospheric accumulation, and the ocean sink. Thus, the land sink accumulates the errors from the other flux terms and bears the largest uncertainty. Here, we present a Bayesian fusion approach that combines multiple observations in different carbon reservoirs to optimize the land (B) and ocean (O) carbon sinks, land use change emissions (L), and indirectly fossil fuel emissions (F) from 1980 to 2014. Compared with the conventional approach, Bayesian optimization decreases the uncertainties in B by 41{\%} and in O by 46{\%}. The L uncertainty decreases by 47{\%}, whereas F uncertainty is marginally improved through the knowledge of natural fluxes. Both ocean and net land uptake (B + L) rates have positive trends of 29 ± 8 and 37 ± 17 Tg C⋅y(-2) since 1980, respectively. Our Bayesian fusion of multiple observations reduces uncertainties, thereby allowing us to isolate important variability in global carbon cycle processes.},
author = {Li, Wei and Ciais, Philippe and Wang, Yilong and Peng, Shushi and Broquet, Gr{\'{e}}goire and Ballantyne, Ashley P. and Canadell, Josep G. and Cooper, Leila and Friedlingstein, Pierre and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Myneni, Ranga B. and Peters, Glen P. and Piao, Shilong and Pongratz, Julia},
doi = {10.1073/pnas.1603956113},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {nov},
number = {46},
pages = {13104--13108},
pmid = {27799533},
title = {{Reducing uncertainties in decadal variability of the global carbon budget with multiple datasets}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1603956113},
volume = {113},
year = {2016}
}
@article{Li2016,
abstract = {Abstract Oxygen depletion in estuaries is a worldwide problem with detrimental effects on many organisms. Although nutrient loading has been stabilized for a number of these systems, seasonal hypoxia persists and displays large year-to-year variations, with larger hypoxic volumes in wetter years and smaller hypoxic volumes in drier years. Data analysis points to climate as a driver of interannual hypoxia variability, but nutrient inputs covary with freshwater flow. Here we report an oxygen budget analysis of Chesapeake Bay to quantify relative contributions of physical and biogeochemical processes. Vertical diffusive flux declines with river discharge, whereas longitudinal advective flux increases with river discharge, such that their total supply of oxygen to bottom water is relatively unchanged. However, water column respiration exhibits large interannual fluctuations and is correlated with primary production and hypoxic volume. Hence, the model results suggest that nutrient loading is the main mechanism driving interannual hypoxia variability in Chesapeake Bay.},
annote = {doi: 10.1002/2015GL067334},
author = {Li, Ming and Lee, Younjoo J and Testa, Jeremy M and Li, Yun and Ni, Wenfei and Kemp, W Michael and {Di Toro}, Dominic M},
doi = {10.1002/2015GL067334},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {climate,hypoxia,interannual variability,nutrient loading},
month = {mar},
number = {5},
pages = {2127--2134},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{What drives interannual variability of hypoxia in Chesapeake Bay: Climate forcing versus nutrient loading?}},
url = {https://doi.org/10.1002/2015GL067334 http://doi.wiley.com/10.1002/2015GL067334},
volume = {43},
year = {2016}
}
@article{Li2019,
abstract = {Strong decadal variations in the oceanic uptake of carbon dioxide (CO 2 ) observed over the past three decades challenge our ability to predict the strength of the ocean carbon sink. By assimilating atmospheric and oceanic observational data products into an Earth system model–based decadal prediction system, we can reproduce the observed variations of the ocean carbon uptake globally. We find that variations of the ocean CO 2 uptake are predictable up to 2 years in advance globally, albeit there is evidence for a higher predictive skill up to 5 years regionally. We further suggest that while temperature variations largely determine shorter-term ({\textless}3 years) predictability, nonthermal drivers are responsible for longer-term ({\textgreater}3 years) predictability, especially at high latitudes.},
author = {Li, H. and Ilyina, T. and M{\"{u}}ller, W. A. and Landsch{\"{u}}tzer, P.},
doi = {10.1126/sciadv.aav6471},
issn = {2375-2548},
journal = {Science Advances},
month = {apr},
number = {4},
pages = {eaav6471},
title = {{Predicting the variable ocean carbon sink}},
url = {http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aav6471},
volume = {5},
year = {2019}
}
@article{Li2016a,
abstract = {As a major CO2 sink, the North Atlantic, especially its subpolar gyre region, is essential for the global carbon cycle. Decadal fluctuations of CO2 uptake in the North Atlantic subpolar gyre region are associated with the evolution of the North Atlantic Oscillation, the Atlantic meridional overturning circulation, ocean mixing and sea surface temperature anomalies. While variations in the physical state of the ocean can be predicted several years in advance by initialization of Earth system models, predictability of CO2 uptake has remained unexplored. Here we investigate the predictability of CO2 uptake variations by initialization of the MPI-ESM decadal prediction system. We find large multi-year variability in oceanic CO2 uptake and demonstrate that its potential predictive skill in the western subpolar gyre region is up to 4-7 years. The predictive skill is mainly maintained in winter and is attributed to the improved physical state of the ocean.},
author = {Li, Hongmei and Ilyina, Tatiana and M{\"{u}}ller, Wolfgang A. and Sienz, Frank},
doi = {10.1038/ncomms11076},
issn = {2041-1723},
journal = {Nature Communications},
month = {apr},
number = {1},
pages = {11076},
title = {{Decadal predictions of the North Atlantic CO2 uptake}},
url = {http://www.nature.com/articles/ncomms11076},
volume = {7},
year = {2016}
}
@article{Li2018c,
abstract = {Abstract The net flux of CO2 exchanged with the atmosphere following grassland-related land-use change (LUC) depends on the subsequent temporal dynamics of soil organic carbon (SOC). Yet, the magnitude and timing of these dynamics are still unclear. We compiled a global data set of 836 paired-sites to quantify temporal SOC changes after grassland-related LUC. In order to discriminate between SOC losses from the initial ecosystem and gains from the secondary one, the post-LUC time series of SOC data was combined with satellite-based net primary production observations as a proxy of carbon input to the soil. Globally, land conversion from either cropland or forest into grassland leads to SOC accumulation; the reverse shows net SOC loss. The SOC response curves vary between different regions. Conversion of cropland to managed grassland results in more SOC accumulation than natural grassland recovery from abandoned cropland. We did not consider the biophysical variables (e.g., climate conditions and soil properties) when fitting the SOC turnover rate into the observation data but analyzed the relationships between the fitted turnover rate and these variables. The SOC turnover rate is significantly correlated with temperature and precipitation (p {\textless} 0.05), but not with the clay fraction of soils (p {\textgreater} 0.05). Comparing our results with predictions from bookkeeping models, we found that bookkeeping models overestimate by 56{\%} of the long-term (100 years horizon) cumulative SOC emissions for grassland-related LUC types in tropical and temperate regions since 2000. We also tested the spatial representativeness of our data set and calculated SOC response curves using the representative subset of sites in each region. Our study provides new insight into the impact grassland-related LUC on the global carbon budget and sheds light on the potential of grassland conservation for climate mitigation.},
author = {Li, Wei and Ciais, Philippe and Guenet, Bertrand and Peng, Shushi and Chang, Jinfeng and Chaplot, Vincent and Khudyaev, Sergey and Peregon, Anna and Piao, Shilong and Wang, Yilong and Yue, Chao},
doi = {10.1111/gcb.14328},
issn = {13541013},
journal = {Global Change Biology},
month = {oct},
number = {10},
pages = {4731--4746},
publisher = {John Wiley {\&} Sons, Ltd (10.1111)},
title = {{Temporal response of soil organic carbon after grassland-related land-use change}},
url = {http://doi.wiley.com/10.1111/gcb.14328},
volume = {24},
year = {2018}
}
@article{Li2018,
abstract = {We investigate the internal decadal variability of the ocean carbon uptake using 100 ensemble simulations based on the Max Planck Institute Earth system model (MPI‐ESM). We find that on decadal time scales, internal variability (ensemble spread) is as large as the forced temporal variability (ensemble mean), and the largest internal variability is found in major carbon sink regions, that is, the 50–65°S band of the Southern Ocean, the North Pacific, and the North Atlantic. The MPI‐ESM ensemble produces both positive and negative 10 year trends in the ocean carbon uptake in agreement with observational estimates. Negative decadal trends are projected to occur in the future under RCP4.5 scenario. Due to the large internal variability, the Southern Ocean and the North Pacific require the most ensemble members (more than 53 and 46, respectively) to reproduce the forced decadal trends. This number increases up to 79 in future decades as CO2 emission trajectory changes.},
author = {Li, Hongmei and Ilyina, Tatiana},
doi = {10.1002/2017GL075370},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Earth system models,decadal trends,forced signal,internal variability,large ensemble simulations,oceanic carbon uptake},
month = {jan},
number = {2},
pages = {916--925},
publisher = {Wiley-Blackwell},
title = {{Current and future decadal trends in the oceanic carbon uptake are dominated by internal variability}},
url = {http://doi.wiley.com/10.1002/2017GL075370 https://onlinelibrary.wiley.com/doi/abs/10.1002/2017GL075370},
volume = {45},
year = {2018}
}
@article{Li2020a,
abstract = {The Southern Ocean plays a crucial role in regulating atmospheric CO2 on centennial to millennial time scales. However, observations of sufficient resolution to explore this have been lacking. Here, we report high-resolution, multiproxy records based on precisely dated deep-sea corals from the Southern Ocean. Paired deep (∆14C and 11B) and surface (15N) proxy data point to enhanced upwelling coupled with reduced efficiency of the biological pump at 14.6 and 11.7 thousand years (ka) ago, which would have facilitated rapid carbon release to the atmosphere. Transient periods of unusually well-ventilated waters in the deep Southern Ocean occurred at 16.3 and 12.8 ka ago. Contemporaneous atmospheric carbon records indicate that these Southern Ocean ventilation events are also important in releasing respired carbon from the deep ocean to the atmosphere. Our results thus highlight two distinct modes of Southern Ocean circulation and biogeochemistry associated with centennial-scale atmospheric CO2 jumps during the last deglaciation.},
author = {Li, Tao and Robinson, Laura F. and Chen, Tianyu and Wang, Xingchen T. and Burke, Andrea and Rae, James W.B. and Pegrum-Haram, Albertine and Knowles, Timothy D.J. and Li, Gaojun and Chen, Jun and Ng, Hong Chin and Prokopenko, Maria and Rowland, George H. and Samperiz, Ana and Stewart, Joseph A. and Southon, John and Spooner, Peter T.},
doi = {10.1126/sciadv.abb3807},
issn = {23752548},
journal = {Science Advances},
number = {42},
pages = {1--10},
pmid = {33067227},
title = {{Rapid shifts in circulation and biogeochemistry of the Southern Ocean during deglacial carbon cycle events}},
volume = {6},
year = {2020}
}
@article{Li2020b,
abstract = {The frequency and intensity of droughts have increased over the decades, leading to increased forest decline. The response of forest to drought can be evaluated by both its sensitivity to drought (resistance) and its post-drought recovery rate (resilience). However, it remains uncertain how drought resistance and resilience of forests change over time under climate change. We assessed the spatiotemporal dynamics of forest resistance and resilience to drought over the past century (1901–2015) with global tree ring data records from 2,935 sites, in conjunction with plant trait data. We found that gymnosperms and angiosperms showed different spatial patterns of drought resistance and resilience, driven by variations in eco-physiological traits. Resistance and resilience also varied with drought seasonal timing. Surprisingly, we found that the trade-off between resistance and resilience for gymnosperms, previously reported only spatially, also occurred at the temporal scale. In particular, drought resilience markedly increased, but resistance decreased, for gymnosperms between 1950–1969 and 1990–2009, indicating that previous model simulations assuming invariant resistance may have underestimated the impacts of drought on gymnosperm-dominated forests under future climate change.},
author = {Li, Xiangyi and Piao, Shilong and Wang, Kai and Wang, Xuhui and Wang, Tao and Ciais, Philippe and Chen, Anping and Lian, Xu and Peng, Shushi and Pe{\~{n}}uelas, Josep},
doi = {10.1038/s41559-020-1217-3},
isbn = {4155902012173},
issn = {2397334X},
journal = {Nature Ecology {\&} Evolution},
number = {8},
pages = {1075--1083},
pmid = {32541804},
publisher = {Springer US},
title = {{Temporal trade-off between gymnosperm resistance and resilience increases forest sensitivity to extreme drought}},
url = {http://dx.doi.org/10.1038/s41559-020-1217-3},
volume = {4},
year = {2020}
}
@article{Lian9999,
abstract = {in press},
author = {Lian, Xu and Piao, Shilong and Chen, Anping and Huntingford, Chris and Fu, Bojie and Li, Laurent Z. X. and Huang, Jianping and Sheffield, Justin and Berg, Alexis M. and Keenan, Trevor F. and McVicar, Tim R. and Wada, Yoshihide and Wang, Xuhui and Wang, Tao and Yang, Yuting and Roderick, Michael L.},
doi = {10.1038/s43017-021-00144-0},
issn = {2662-138X},
journal = {Nature Reviews Earth {\&} Environment},
month = {apr},
number = {4},
pages = {232--250},
title = {{Multifaceted characteristics of dryland aridity changes in a warming world}},
url = {http://www.nature.com/articles/s43017-021-00144-0},
volume = {2},
year = {2021}
}
@article{Lilly2019,
abstract = {Abstract We analyzed impacts of the 2014?2015 Pacific Warm Anomaly and 2015?2016 El Ni{\~{n}}o on physical and biogeochemical variables at two southern California Current System moorings (CCE2, nearshore upwelling off Point Conception; CCE1, offshore California Current). Nitrate and Chl-a fluorescence were {\textless}1 ?M and {\textless}1 Standardized Fluorescence Unit, respectively, at CCE2 for the entire durations of the Warm Anomaly and El Ni{\~{n}}o, the two longest periods of such low values in our time series. Negative nitrate and Chl-a anomalies at CCE2 were interrupted briefly by upwelling conditions in spring 2015. Near-surface temperature anomalies appeared simultaneously at both moorings in spring 2014, indicating region-wide onset of Warm Anomaly temperatures, although sustained negative nitrate and Chl-a anomalies only occurred offshore at CCE1 during El Ni{\~{n}}o (summer 2015 to spring 2016). Warm Anomaly temperature changes were expressed more strongly in near-surface ({\textless}40 m) than subsurface (75 m) waters at both moorings, while El Ni{\~{n}}o produced comparable temperature anomalies at near-surface and subsurface depths. Nearshore $\Omega$aragonite at 76 m showed notably fewer undersaturation events during both warm periods, suggesting an environment more conducive to calcifying organisms. Planktonic calcifying molluscs (pteropods and heteropods) increased markedly in springs 2014 and 2016 and remained modestly elevated in spring 2015. Moorings provide high-frequency measurements essential for resolving the onset timing of anomalous conditions and frequency and duration of short-term (days-to-weeks) perturbations (reduced nitrate and aragonite undersaturation events) that can affect marine organisms.},
annote = {From Duplicate 1 (Biogeochemical Anomalies at Two Southern California Current System Moorings During the 2014–2016 Warm Anomaly‐El Ni{\~{n}}o Sequence - Lilly, Laura E; Send, Uwe; Lankhorst, Matthias; Martz, Todd R; Feely, Richard A; Sutton, Adrienne J; Ohman, Mark D)

doi: 10.1029/2019JC015255},
author = {Lilly, Laura E and Send, Uwe and Lankhorst, Matthias and Martz, Todd R and Feely, Richard A and Sutton, Adrienne J and Ohman, Mark D},
doi = {10.1029/2019JC015255},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {California Current System,El Ni{\~{n}}o,aragonite saturation,moorings,pteropods,warm anomaly},
month = {oct},
number = {10},
pages = {6886--6903},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Biogeochemical Anomalies at Two Southern California Current System Moorings During the 2014–2016 Warm Anomaly-El Ni{\~{n}}o Sequence}},
url = {https://doi.org/10.1029/2019JC015255 https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015255 https://onlinelibrary.wiley.com/doi/10.1029/2019JC015255},
volume = {124},
year = {2019}
}
@article{Limburg2020a,
abstract = {Earth's ocean is losing oxygen; since the mid-20th century, 1{\%}–2{\%} of the global ocean oxygen inventory has been lost, and over 700 coastal sites have reported new or worsening low-oxygen conditions. This “ocean deoxygenation” is increasing and of great concern because of the potential magnitude of adverse changes to both global and local marine ecosystems. Oxygen is fundamental for life and biogeochemical processes in the ocean. In coastal and shelf regions and semi-enclosed seas, over-fertilization of waters largely from agriculture, sewage, and airborne sources creates algal blooms that die and decay, consuming oxygen. Globally, climate warming both exacerbates the problems from eutrophication and reduces the introduction of oxygen to the interior of the ocean. We discuss mechanisms, scale, assessments, projections, and impacts, including impacts to human well-being, at the individual, community, and ecosystem levels. Deoxygenation together with other stressors presents a major environmental challenge to sustainability and human use of the ocean.},
author = {Limburg, Karin E and Breitburg, Denise and Swaney, Dennis P and Jacinto, Gil},
doi = {10.1016/j.oneear.2020.01.001},
issn = {2590-3322},
journal = {One Earth},
number = {1},
pages = {24--29},
title = {{Ocean Deoxygenation: A Primer}},
volume = {2},
year = {2020}
}
@article{10.1093/treephys/tpr141,
abstract = {The response of photosynthesis to temperature is a central facet of plant response to climate. Such responses have been found to be highly variable among species and among studies. Understanding this variability is key when trying to predict the effects of rising global temperatures on plant productivity. There are three major factors affecting the response of leaf net photosynthesis to temperature (An–T): (i) photosynthetic biochemistry, (ii) respiration and (iii) vapour pressure deficit (D) and stomatal sensitivity to vapour pressure deficit during measurements. The overall goal of our study was to quantify the relative contribution of each of these factors in determining the response of An to temperature. We first conducted a sensitivity analysis with a coupled photosynthesis–stomatal (An–gs) model, using ranges for parameters of each factor taken from the literature, and quantified how these parameters affected the An–T response. Second, we applied the An–gs model to two example sets of field data, which had different optimum temperatures (Topt) of An, to analyse which factors were most important in causing the difference. We found that each of the three factors could have an equally large effect on Topt of An. In our comparison between two field datasets, the major cause for the difference in Topt was not the biochemical component, but rather the differences in respiratory components and in D conditions during measurements. We concluded that shifts in An–T responses are not always driven by acclimation of photosynthetic biochemistry, but can result from other factors. The D conditions during measurements and stomatal responses to D also need to be quantified if we are to better understand and predict shifts in An–T with climate.},
author = {Lin, Yan-Shih and Medlyn, Belinda E and Ellsworth, David S},
doi = {10.1093/treephys/tpr141},
issn = {0829-318X},
journal = {Tree Physiology},
number = {2},
pages = {219--231},
title = {{Temperature responses of leaf net photosynthesis: the role of component processes}},
url = {https://doi.org/10.1093/treephys/tpr141},
volume = {32},
year = {2012}
}
@article{Lindgren2018,
abstract = {Atmospheric concentrations of carbon dioxide increased between the Last Glacial Maximum (LGM, around 21,000 years ago) and the preindustrial era1. It is thought that the evolution of this atmospheric carbon dioxide (and that of atmospheric methane) during the glacial-to-interglacial transition was influenced by organic carbon that was stored in permafrost during the LGM and then underwent decomposition and release following thaw2,3. It has also been suggested that the rather erratic atmospheric $\delta$13C and ∆14C signals seen during deglaciation1,4 could partly be explained by the presence of a large terrestrial inert LGM carbon stock, despite the biosphere being less productive (and therefore storing less carbon)5,6. Here we present an empirically derived estimate of the carbon stored in permafrost during the LGM by reconstructing the extent and carbon content of LGM biomes, peatland regions and deep sedimentary deposits. We find that the total estimated soil carbon stock for the LGM northern permafrost region is smaller than the estimated present-day storage (in both permafrost and non-permafrost soils) for the same region. A substantial decrease in the permafrost area from the LGM to the present day has been accompanied by a roughly 400-petagram increase in the total soil carbon stock. This increase in soil carbon suggests that permafrost carbon has made no net contribution to the atmospheric carbon pool since the LGM. However, our results also indicate potential postglacial reductions in the portion of the carbon stock that is trapped in permafrost, of around 1,000 petagrams, supporting earlier studies7. We further find that carbon has shifted from being primarily stored in permafrost mineral soils and loess deposits during the LGM, to being roughly equally divided between peatlands, mineral soils and permafrost loess deposits today.},
author = {Lindgren, Amelie and Hugelius, Gustaf and Kuhry, Peter},
doi = {10.1038/s41586-018-0371-0},
issn = {1476-4687},
journal = {Nature},
number = {7717},
pages = {219--222},
title = {{Extensive loss of past permafrost carbon but a net accumulation into present-day soils}},
url = {https://doi.org/10.1038/s41586-018-0371-0},
volume = {560},
year = {2018}
}
@article{Lippold2016,
abstract = {Reconstructing past modes of ocean circulation is an essential task in paleoclimatology and paleoceanography. To this end, we combine two sedimentary proxies, Nd isotopes ($\epsilon$Nd) and the 231Pa/230Th ratio, both of which are not directly involved in the global carbon cycle, but allow the reconstruction of water mass provenance and provide information about the past strength of overturning circulation, respectively. In this study, combined 231Pa/230Th and $\epsilon$Nd down-core profiles from six Atlantic Ocean sediment cores are presented. The data set is complemented by the two available combined data sets from the literature. From this we derive a comprehensive picture of spatial and temporal patterns and the dynamic changes of the Atlantic Meridional Overturning Circulation over the past {\~{}}25 ka. Our results provide evidence for a consistent pattern of glacial/stadial advances of Southern Sourced Water along with a northward circulation mode for all cores in the deeper ({\textgreater}3000 m) Atlantic. Results from shallower core sites support an active overturning cell of shoaled Northern Sourced Water during the LGM and the subsequent deglaciation. Furthermore, we report evidence for a short-lived period of intensified AMOC in the early Holocene.},
author = {Lippold, J{\"{o}}rg and Gutjahr, Marcus and Blaser, Patrick and Christner, Emanuel and {de Carvalho Ferreira}, Maria Luiza and Mulitza, Stefan and Christl, Marcus and Wombacher, Frank and B{\"{o}}hm, Evelyn and Antz, Benny and Cartapanis, Olivier and Vogel, Hendrik and Jaccard, Samuel L.},
doi = {10.1016/j.epsl.2016.04.013},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {231Pa/230Th,Atlantic Meridional Overturning Circulation,Deep sea sediments,Deglaciation,Last Glacial Maximum,$\epsilon$Nd},
month = {jul},
pages = {68--78},
title = {{Deep water provenance and dynamics of the (de)glacial Atlantic meridional overturning circulation}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X16301698},
volume = {445},
year = {2016}
}
@article{Liu2017d,
author = {Liu, Zunqi and He, Tianyi and Cao, Ting and Yang, Tiexing and Meng, Jun and Chen, Wenfu},
doi = {10.4067/S0718-95162017005000037},
issn = {0718-9516},
journal = {Journal of soil science and plant nutrition},
number = {2},
pages = {515--528},
publisher = {scielocl},
title = {{Effects of biochar application on nitrogen leaching, ammonia volatilization and nitrogen use efficiency in two distinct soils}},
url = {https://scielo.conicyt.cl/scielo.php?script=sci{\_}arttext{\&}pid=S0718-95162017000200018{\&}nrm=iso http://www.scielo.cl/scielo.php?script=sci{\_}arttext{\&}pid=S0718-95162017005000037{\&}lng=en{\&}nrm=iso{\&}tlng=en},
volume = {17},
year = {2017}
}
@article{Liu2014,
abstract = {Acceleration of modern acidification in the South China Sea driven by anthropogenic CO2},
author = {Liu, Yi and Peng, Zicheng and Zhou, Renjun and Song, Shaohua and Liu, Weiguo and You, Chen-Feng and Lin, Yen-Po and Yu, Kefu and Wu, Chung-Che and Wei, Gangjian and Xie, Luhua and Burr, George S. and Shen, Chuan-Chou},
doi = {10.1038/srep05148},
issn = {2045-2322},
journal = {Scientific Reports},
keywords = {Climate,Marine chemistry,Palaeoclimate,change impacts},
month = {may},
number = {1},
pages = {5148},
publisher = {Nature Publishing Group},
title = {{Acceleration of modern acidification in the South China Sea driven by anthropogenic CO2}},
url = {http://www.nature.com/articles/srep05148},
volume = {4},
year = {2014}
}
@article{Liu2016,
abstract = {A hydrologically contained field study, to assess biochar (produced from mixed crop straws) influence upon soil hydraulic properties and dissolved organic carbon (DOC) leaching, was conducted on a loamy soil (entisol). The soil, noted for its low plant-available water and low soil organic matter, is the most important arable soil type in the upper reaches of the Yangtze River catchment, China. Pore size distribution characterization (by N2 adsorption, mercury intrusion, and water retention) showed that the biochar had a tri-modal pore size distribution. This included pores with diameters in the range of 0.1--10 {\$}\mu{\$}m that can retain plant-available water. Comparison of soil water retention curves between the control (0) and the biochar plots (16 t ha−1 on dry weight basis) demonstrated biochar amendment to increase soil water holding capacity. However, significant increases in DOC concentration of soil pore water in both the plough layer and the undisturbed subsoil layer were observed in the biochar-amended plots. An increased loss of DOC relative to the control was observed upon rainfall events. Measurements of excitation-emission matrix (EEM) fluorescence indicated the DOC increment originated primarily from the organic carbon pool in the soil that became more soluble following biochar incorporation.},
author = {Liu, Chen and Wang, Honglan and Tang, Xiangyu and Guan, Zhuo and Reid, Brian J and Rajapaksha, Anushka Upamali and Ok, Yong Sik and Sun, Hui},
doi = {10.1007/s11356-015-4885-9},
issn = {1614-7499},
journal = {Environmental Science and Pollution Research},
number = {2},
pages = {995--1006},
title = {{Biochar increased water holding capacity but accelerated organic carbon leaching from a sloping farmland soil in China}},
volume = {23},
year = {2016}
}
@article{Liu_2019,
abstract = {The directionality of the response of gross primary productivity (GPP) to climate has been shown to vary across the globe. This effect has been hypothesized to be the result of the interaction between multiple bioclimatic factors, including environmental energy (i.e. temperature and radiation) and water availability. This is due to the tight coupling between water and carbon cycling in plants and the fact that temperature often drives plant water demand. Using GPP data extracted from 188 sites of FLUXNET2015 and observation-driven terrestrial biosphere models (TBMs), we disentangled the confounding effects of temperature, precipitation and carbon dioxide on GPP, and examined their long-term effects on productivity across the globe. Based on the FLUXNET2015 data, we observed a decline in the positive effect of temperature on GPP, while the positive effects of precipitation and CO2 were becoming stronger during 2000–2014. Using data derived from TBMs between 1980 and 2010 we found similar effects globally. The modeled data allowed us to investigate these effects more thoroughly over space and time. In arid regions, the modeled response to precipitation increased since 1950, approximately 30 years earlier than in humid regions. We further observed the negative effects of summer temperature on GPP in arid regions, suggesting greater aridity stress on productivity under global warming. Our results imply that aridity stress, triggered by rising temperatures, has reduced the positive influence of temperature on GPP, while increased precipitation and elevated CO2 may alleviate negative aridity impacts.},
author = {Liu, Zhiyong and Chen, Lei and Smith, Nicholas G and Yuan, Wenping and Chen, Xiaohong and Zhou, Guoyi and Alam, Syed Ashraful and Lin, Kairong and Zhao, Tongtiegang and Zhou, Ping and Chu, Chengjin and Ma, Hanqing and Liu, Jianquan},
doi = {10.1088/1748-9326/ab57c5},
journal = {Environmental Research Letters},
month = {dec},
number = {12},
pages = {124044},
publisher = {{\{}IOP{\}} Publishing},
title = {{Global divergent responses of primary productivity to water, energy, and CO2}},
url = {https://doi.org/10.1088{\%}2F1748-9326{\%}2Fab57c5},
volume = {14},
year = {2019}
}
@article{Liu2017,
abstract = {The 2015-2016 El Nino led to historically high temperatures and low precipitation over the tropics, while the growth rate of atmospheric carbon dioxide (CO2) was the largest on record. Here we quantify the response of tropical net biosphere exchange, gross primary production, biomass burning, and respiration to these climate anomalies by assimilating column CO2, solar-induced chlorophyll fluorescence, and carbon monoxide observations from multiple satellites. Relative to the 2011 La Nina, the pantropical biosphere released 2.5 +/- 0.34 gigatons more carbon into the atmosphere in 2015, consisting of approximately even contributions from three tropical continents but dominated by diverse carbon exchange processes. The heterogeneity of the carbon-exchange processes indicated here challenges previous studies that suggested that a single dominant process determines carbon cycle interannual variability.},
annote = {Liu, Junjie
Bowman, Kevin W
Schimel, David S
Parazoo, Nicolas C
Jiang, Zhe
Lee, Meemong
Bloom, A Anthony
Wunch, Debra
Frankenberg, Christian
Sun, Ying
O'Dell, Christopher W
Gurney, Kevin R
Menemenlis, Dimitris
Gierach, Michelle
Crisp, David
Eldering, Annmarie
eng
Research Support, U.S. Gov't, Non-P.H.S.
New York, N.Y.
2017/10/14 06:00
Science. 2017 Oct 13;358(6360). pii: 358/6360/eaam5690. doi: 10.1126/science.aam5690.},
author = {Liu, Junjie and Bowman, Kevin W and Schimel, David S and Parazoo, Nicolas C and Jiang, Zhe and Lee, Meemong and Bloom, A Anthony and Wunch, Debra and Frankenberg, Christian and Sun, Ying and O'Dell, Christopher W. and Gurney, Kevin R and Menemenlis, Dimitris and Gierach, Michelle and Crisp, David and Eldering, Annmarie},
doi = {10.1126/science.aam5690},
issn = {0036-8075},
journal = {Science},
month = {oct},
number = {6360},
pages = {eaam5690},
pmid = {29026011},
title = {{Contrasting carbon cycle responses of the tropical continents to the 2015–2016 El Ni{\~{n}}o}},
url = {https://www.science.org/doi/10.1126/science.aam5690},
volume = {358},
year = {2017}
}
@article{Liu2020a,
abstract = {The COVID-19 pandemic is impacting human activities, and in turn energy use and carbon dioxide (CO 2 ) emissions. Here we present daily estimates of country-level CO 2 emissions for different sectors based on near-real-time activity data. The key result is an abrupt 8.8{\%} decrease in global CO 2 emissions (−1551 Mt CO 2 ) in the first half of 2020 compared to the same period in 2019. The magnitude of this decrease is larger than during previous economic downturns or World War II. The timing of emissions decreases corresponds to lockdown measures in each country. By July 1st, the pandemic's effects on global emissions diminished as lockdown restrictions relaxed and some economic activities restarted, especially in China and several European countries, but substantial differences persist between countries, with continuing emission declines in the U.S. where coronavirus cases are still increasing substantially.},
author = {Liu, Zhu and Ciais, Philippe and Deng, Zhu and Lei, Ruixue and Davis, Steven J and Feng, Sha and Zheng, Bo and Cui, Duo and Dou, Xinyu and Zhu, Biqing and Guo, Rui and Ke, Piyu and Sun, Taochun and Lu, Chenxi and He, Pan and Wang, Yuan and Yue, Xu and Wang, Yilong and Lei, Yadong and Zhou, Hao and Cai, Zhaonan and Wu, Yuhui and Guo, Runtao and Han, Tingxuan and Xue, Jinjun and Boucher, Olivier and Boucher, Eulalie and Chevallier, Fr{\'{e}}d{\'{e}}ric and Tanaka, Katsumasa and Wei, Yimin and Zhong, Haiwang and Kang, Chongqing and Zhang, Ning and Chen, Bin and Xi, Fengming and Liu, Miaomiao and Br{\'{e}}on, Fran{\c{c}}ois-Marie and Lu, Yonglong and Zhang, Qiang and Guan, Dabo and Gong, Peng and Kammen, Daniel M and He, Kebin and Schellnhuber, Hans Joachim},
doi = {10.1038/s41467-020-18922-7},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {5172},
title = {{Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic}},
url = {https://doi.org/10.1038/s41467-020-18922-7 http://www.nature.com/articles/s41467-020-18922-7},
volume = {11},
year = {2020}
}
@article{Liu2020,
abstract = {Nitrous oxide (N2O) is approximately 265 times more potent than carbon dioxide (CO2) in atmospheric warming. Degraded peatlands are important sources of N2O. The more a peat soil is degraded, the higher the N2O-N emissions from peat. In this study, soil bulk density was used as a proxy for peat degradation to predict N2O-N emissions. Here we report that the annual N2O-N emissions from European managed peatlands (EU-28) sum up to approximately 145 Gg N year−1. From the viewpoint of greenhouse gas emissions, highly degraded agriculturally used peatlands should be rewetted first to optimally reduce cumulative N2O-N emissions. Compared to a business-as-usual scenario (no peatland rewetting), rewetting of all drained European peatlands until 2050 using the suggested strategy reduces the cumulative N2O-N emissions by 70{\%}. In conclusion, the status of peat degradation should be made a pivotal criterion in prioritising peatlands for restoration.},
author = {Liu, Haojie and Wrage-M{\"{o}}nnig, Nicole and Lennartz, Bernd},
doi = {10.1038/s43247-020-00017-2},
issn = {2662-4435},
journal = {Communications Earth {\&} Environment},
number = {1},
pages = {17},
title = {{Rewetting strategies to reduce nitrous oxide emissions from European peatlands}},
url = {https://doi.org/10.1038/s43247-020-00017-2},
volume = {1},
year = {2020}
}
@article{Liu2020b,
abstract = {Dryness stress can limit vegetation growth and is often characterized by low soil moisture (SM) and high atmospheric water demand (vapor pressure deficit, VPD). However, the relative role of SM and VPD in limiting ecosystem production remains debated and is difficult to disentangle, as SM and VPD are coupled through land-atmosphere interactions, hindering the ability to predict ecosystem responses to dryness. Here, we combine satellite observations of solar-induced fluorescence with estimates of SM and VPD and show that SM is the dominant driver of dryness stress on ecosystem production across more than 70{\%} of vegetated land areas with valid data. Moreover, after accounting for SM-VPD coupling, VPD effects on ecosystem production are much smaller across large areas. We also find that SM stress is strongest in semi-arid ecosystems. Our results clarify a longstanding question and open new avenues for improving models to allow a better management of drought risk.},
author = {Liu, Laibao and Gudmundsson, Lukas and Hauser, Mathias and Qin, Dahe and Li, Shuangcheng and Seneviratne, Sonia I.},
doi = {10.1038/s41467-020-18631-1},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {4892},
pmid = {32994398},
publisher = {Springer US},
title = {{Soil moisture dominates dryness stress on ecosystem production globally}},
url = {http://dx.doi.org/10.1038/s41467-020-18631-1 https://www.nature.com/articles/s41467-020-18631-1},
volume = {11},
year = {2020}
}
@article{Llanillo2013a,
abstract = {Abstract. Temporal changes in the water mass distribution and biogeochemical signals in the tropical eastern South Pacific are investigated with the help of an extended optimum multi-parameter (OMP) analysis, a technique for inverse modeling of mixing and biogeochemical processes through a multidimensional least-square fit. Two ship occupations of a meridional section along 85°50' W from 14° S to 1° N are analysed during relatively warm (El Ni{\~{n}}o/El Viejo, March 1993) and cold (La Ni{\~{n}}a/La Vieja, February 2009) upper-ocean phases. The largest El Ni{\~{n}}o–Southern Oscillation (ENSO) impact was found in the water properties and water mass distribution in the upper 200 m north of 10° S. ENSO promotes the vertical motion of the oxygen minimum zone (OMZ) associated with the hypoxic equatorial subsurface water (ESSW). During a cold phase the core of the ESSW is found at shallower layers, replacing shallow (top 200 m) subtropical surface water (STW). The heave of isopycnals due to ENSO partially explains the intrusion of oxygen-rich and nutrient-poor antarctic intermediate water (AAIW) into the depth range of 150–500 m. The other cause of the AAIW increase at shallower depths is that this water mass flowed along shallower isopycnals in 2009. The shift in the vertical location of AAIW reaching the OMZ induces changes in the amount of oxygen advected and respired inside the OMZ: the larger the oxygen supply, the greater the respiration and the lower the nitrate loss through denitrification. Variations in the intensity of the zonal currents in the equatorial current system, which ventilates the OMZ from the west, are used to explain the patchy latitudinal changes of seawater properties observed along the repeated section. Significant changes reach down to 800 m, suggesting that decadal variability (Pacific decadal oscillation) is also a potential driver in the observed variability.},
author = {Llanillo, P J and Karstensen, J and Pelegr{\'{i}}, J. L. and Stramma, L},
doi = {10.5194/bg-10-6339-2013},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {10},
pages = {6339--6355},
title = {{Physical and biogeochemical forcing of oxygen and nitrate changes during El Ni{\~{n}}o/El Viejo and La Ni{\~{n}}a/La Vieja upper-ocean phases in the tropical eastern South Pacific along 86°W}},
url = {https://bg.copernicus.org/articles/10/6339/2013/},
volume = {10},
year = {2013}
}
@article{doi:10.1111/j.1365-2486.2011.02624.x,
abstract = {Abstract Current climatic trends involve both increasing temperatures and climatic variability, with extreme events becoming more frequent. Increasing concern on extreme climatic events has triggered research on vegetation shifts. However, evidences of vegetation shifts resulting from these events are still relatively rare. Empirical evidence supports the existence of stabilizing processes minimizing and counteracting the effects of these events, reinforcing community resilience. We propose a demographic framework to understand this inertia to change based on the balance between adult mortality induced by the event and enhanced recruitment or adult survival after the event. The stabilizing processes potentially contributing to this compensation include attenuation of the adult mortality caused by the event, due to site quality variability, to tolerance, phenotypic variability, and plasticity at population level, and to facilitative interactions. Mortality compensation may also occur by increasing future survival due to beneficial effect on growth and survival of the new conditions derived from global warming and increased climatic variability, to lowered competition resulting from reduced density in affected stands, or to antagonistic release when pathogens or predators are vulnerable to the event or the ongoing climatic conditions. Finally, mortality compensation may appear by enhanced recruitment due to release of competition with established vegetation, for instance as a consequence of gap openings after event-caused mortality, or to the new conditions, which may be more favorable for seedling establishment, or to enhanced mutualistic interactions (pollination, dispersal). There are important challenges imposed by the need of long-term studies, but a research agenda focused on potentially stabilizing processes is well suited to understand the variety of responses, including lack of sudden changes and community inertia that are frequently observed in vegetation under extreme events. This understanding is crucial for the establishment of sound management strategies and actions addressed to improve ecosystem resilience under climate change scenarios.},
annote = {added by A.Eliseev 25.01.2019},
author = {Lloret, Francisco and Escudero, Adrian and Iriondo, Jos{\'{e}} Mar{\'{i}}a and Mart{\'{i}}nez-Vilalta, Jordi and Valladares, Fernando},
doi = {10.1111/j.1365-2486.2011.02624.x},
issn = {13541013},
journal = {Global Change Biology},
keywords = {climate change,extreme climatic events,forest dieback,plant community resilience,vegetation dynamics},
month = {mar},
number = {3},
pages = {797--805},
title = {{Extreme climatic events and vegetation: the role of stabilizing processes}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2486.2011.02624.x http://doi.wiley.com/10.1111/j.1365-2486.2011.02624.x},
volume = {18},
year = {2012}
}
@article{Loisel2014,
author = {Loisel, Julie and Yu, Zicheng and Beilman, David W and Camill, Philip and Alm, Jukka and Amesbury, Matthew J and Anderson, David and Andersson, Sofia and Bochicchio, Christopher and Barber, Keith and Belyea, Lisa R and Bunbury, Joan and Chambers, Frank M and Charman, Daniel J and {De Vleeschouwer}, Fran{\c{c}}ois and Fia{\l}kiewicz-Kozie{\l}, Barbara and Finkelstein, Sarah A and Ga{\l}ka, Mariusz and Garneau, Michelle and Hammarlund, Dan and Hinchcliffe, William and Holmquist, James and Hughes, Paul and Jones, Miriam C and Klein, Eric S and Kokfelt, Ulla and Korhola, Atte and Kuhry, Peter and Lamarre, Alexandre and Lamentowicz, Mariusz and Large, David and Lavoie, Martin and MacDonald, Glen and Magnan, Gabriel and M{\"{a}}kil{\"{a}}, Markku and Mallon, Gunnar and Mathijssen, Paul and Mauquoy, Dmitri and McCarroll, Julia and Moore, Tim R and Nichols, Jonathan and O'Reilly, Benjamin and Oksanen, Pirita and Packalen, Maara and Peteet, Dorothy and Richard, Pierre JH and Robinson, Stephen and Ronkainen, Tiina and Rundgren, Mats and Sannel, A Britta K and Tarnocai, Charles and Thom, Tim and Tuittila, Eeva-Stiina and Turetsky, Merritt and V{\"{a}}liranta, Minna and van der Linden, Marjolein and van Geel, Bas and van Bellen, Simon and Vitt, Dale and Zhao, Yan and Zhou, Weijian},
doi = {10.1177/0959683614538073},
issn = {0959-6836},
journal = {The Holocene},
month = {sep},
number = {9},
pages = {1028--1042},
title = {{A database and synthesis of northern peatland soil properties and Holocene carbon and nitrogen accumulation}},
url = {http://journals.sagepub.com/doi/10.1177/0959683614538073},
volume = {24},
year = {2014}
}
@article{Lombardozzi2015a,
abstract = {Abstract Earth System Models typically use static responses to temperature to calculate photosynthesis and respiration, but experimental evidence suggests that many plants acclimate to prevailing temperatures. We incorporated representations of photosynthetic and leaf respiratory temperature acclimation into the Community Land Model, the terrestrial component of the Community Earth System Model. These processes increased terrestrial carbon pools by 20?Pg?C (22{\%}) at the end of the 21st century under a business-as-usual (Representative Concentration Pathway 8.5) climate scenario. Including the less certain estimates of stem and root respiration acclimation increased terrestrial carbon pools by an additional 17?Pg?C ({\~{}}40{\%} overall increase). High latitudes gained the most carbon with acclimation, and tropical carbon pools increased least. However, results from both of these regions remain uncertain; few relevant data exist for tropical and boreal plants or for extreme temperatures. Constraining these uncertainties will produce more realistic estimates of land carbon feedbacks throughout the 21st century.},
author = {Lombardozzi, Danica L and Bonan, Gordon B and Smith, Nicholas G and Dukes, Jeffrey S and Fisher, Rosie A},
doi = {10.1002/2015GL065934},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {oct},
number = {20},
pages = {8624--8631},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Temperature acclimation of photosynthesis and respiration: A key uncertainty in the carbon cycle–climate feedback}},
url = {http://doi.wiley.com/10.1002/2015GL065934},
volume = {42},
year = {2015}
}
@article{Long2016a,
abstract = {Abstract Anthropogenically forced trends in oceanic dissolved oxygen are evaluated in Earth system models in the context of natural variability. A large ensemble of a single Earth system model is used to clearly identify the forced component of change in interior oxygen distributions and to evaluate the magnitude of this signal relative to noise generated by internal climate variability. The time of emergence of forced trends is quantified on the basis of anomalies in oxygen concentrations and trends. We find that the forced signal should already be evident in the southern Indian Ocean and parts of the eastern tropical Pacific and Atlantic basins; widespread detection of forced deoxygenation is possible by 2030–2040. In addition to considering spatially discrete metrics of detection, we evaluate the similarity of the spatial structures associated with natural variability and the forced trend. Outside of the subtropics, these patterns are not wholly distinct on the isopycnal surfaces considered, and therefore, this approach does not provide significantly advanced detection. Our results clearly demonstrate the strong impact of natural climate variability on interior oxygen distributions, providing an important context for interpreting observations.},
author = {Long, Matthew C and Deutsch, Curtis and Ito, Taka},
doi = {10.1002/2015GB005310},
journal = {Global Biogeochemical Cycles},
number = {2},
pages = {381--397},
title = {{Finding forced trends in oceanic oxygen}},
volume = {30},
year = {2016}
}
@article{https://doi.org/10.1002/jpln.201400058,
abstract = {Abstract Pyrogenic carbon (C) is produced by incomplete combustion of fuels including organic matter (OM). Certain ranges in the combustion continuum are termed ‘black carbon' (BC). Because of its assumed persistence, surface soils in large parts of the world contain BC with up to 80{\%} of surface soil organic C (SOC) stocks and up to 32{\%} of subsoil SOC in agricultural soils consisting of BC. High SOC stocks and high levels of soil fertility in some ancient soils containing charcoal (e.g., terra preta de {\'{I}}ndio) have recently been used as strategies for soil applications of biochar, an engineered BC material similar to charcoal but with the purposeful use as a soil conditioner (1) to mitigate increases in atmospheric carbon dioxide (CO2) by SOC sequestration and (2) to enhance soil fertility. However, effects of biochar on soils and crop productivity cannot be generalized as they are biochar-, plant- and site-specific. For example, the largest potential increases in crop yields were reported in areas with highly weathered soils, such as those characterizing much of the humid tropics. Soils of high inherent fertility, characterizing much of the world's important agricultural areas, appear to be less likely to benefit from biochar. It has been hypothesized that both liming and aggregating/moistening effects of biochar improved crop productivity. Meta-analyses of biochar effects on SOC sequestration have not yet been reported. To effectively mitigate climate change by SOC sequestration, a net removal of C and storage in soil relative to atmospheric CO2 must occur and persist for several hundred years to a few millennia. At deeper soil depths, SOC is characterized by long turnover times, enhanced stabilization, and less vulnerability to loss by decomposition and erosion. In fact, some studies have reported preferential long-term accumulation of BC at deeper depths. Thus, it is hypothesized that surface applied biochar-C (1) must be translocated to subsoil layers and (2) result in deepening of SOC distribution for a notable contribution to climate change mitigation. Detailed studies are needed to understand how surface-applied biochar can move to deeper soil depths, and how its application affects organic C input to deeper soil depths. Based on this knowledge, biochar systems for climate change mitigation through SOC sequestration can be designed. It is critically important to identify mechanisms underlying the sometimes observed negative effects of biochar application on biomass, yield and SOC as biochar may persist in soils for long periods of time as well as the impacts on downstream environments and the net climate impact when biochar particles become airborne.},
author = {Lorenz, Klaus and Lal, Rattan},
doi = {10.1002/jpln.201400058},
journal = {Journal of Plant Nutrition and Soil Science},
keywords = {biochar,black carbon,crop productivity,soil organic carbon sequestration},
number = {5},
pages = {651--670},
title = {{Biochar application to soil for climate change mitigation by soil organic carbon sequestration}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/jpln.201400058},
volume = {177},
year = {2014}
}
@article{Loulergue2008,
abstract = {Atmospheric methane is an important greenhouse gas and a sensitive indicator of climate change and millennial-scale temperature variability1. Its concentrations over the past 650,000 years have varied between ∼350 and ∼800 parts per 109 by volume (p.p.b.v.) during glacial and interglacial periods, respectively2. In comparison, present-day methane levels of ∼1,770 p.p.b.v. have been reported3. Insights into the external forcing factors and internal feedbacks controlling atmospheric methane are essential for predicting the methane budget in a warmer world3. Here we present a detailed atmospheric methane record from the EPICA Dome C ice core that extends the history of this greenhouse gas to 800,000 yr before present. The average time resolution of the new data is ∼380 yr and permits the identification of orbital and millennial-scale features. Spectral analyses indicate that the long-term variability in atmospheric methane levels is dominated by ∼100,000 yr glacial–interglacial cycles up to ∼400,000 yr ago with an increasing contribution of the precessional component during the four more recent climatic cycles. We suggest that changes in the strength of tropical methane sources and sinks (wetlands, atmospheric oxidation), possibly influenced by changes in monsoon systems and the position of the intertropical convergence zone, controlled the atmospheric methane budget, with an additional source input during major terminations as the retreat of the northern ice sheet allowed higher methane emissions from extending periglacial wetlands. Millennial-scale changes in methane levels identified in our record as being associated with Antarctic isotope maxima events1,4 are indicative of ubiquitous millennial-scale temperature variability during the past eight glacial cycles.},
author = {Loulergue, Laetitia and Schilt, Adrian and Spahni, Renato and Masson-Delmotte, Val{\'{e}}rie and Blunier, Thomas and Lemieux, B{\'{e}}n{\'{e}}dicte and Barnola, Jean-Marc and Raynaud, Dominique and Stocker, Thomas F. and Chappellaz, J{\'{e}}r{\^{o}}me},
doi = {10.1038/nature06950},
issn = {0028-0836},
journal = {Nature},
month = {may},
number = {7193},
pages = {383--386},
publisher = {Nature Publishing Group},
title = {{Orbital and millennial-scale features of atmospheric CH4 over the past 800,000 years}},
url = {http://www.nature.com/doifinder/10.1038/nature06950},
volume = {453},
year = {2008}
}
@article{Lovelock2019,
abstract = {Blue Carbon is a term coined in 2009 to draw attention to the degradation of marine and coastal ecosystems and the need to conserve and restore them to mitigate climate change and for the other ecosystem services they provide. Blue Carbon has multiple meanings, which we aim to clarify here, which reflect the original descriptions of the concept including (1) all organic matter captured by marine organisms, and (2) how marine ecosystems could be managed to reduce greenhouse gas emissions and thereby contribute to climate change mitigation and conservation. The multifaceted nature of the Blue Carbon concept has led to unprecedented collaboration across disciplines, where scientists, conservationists and policy makers have interacted intensely to advance shared goals. Some coastal ecosystems (mangroves, tidal marshes and seagrass) are established Blue Carbon ecosystems as they often have high carbon stocks, support long-term carbon storage, offer the potential to manage greenhouse gas emissions and support other adaptation policies. Some marine ecosystems do not meet key criteria for inclusion within the Blue Carbon framework (e.g. fish, bivalves and coral reefs). Others have gaps in scientific understanding of carbon stocks or greenhouse gas fluxes, or currently there is limited potential for management or accounting for carbon sequestration (macroalgae and phytoplankton), but may be considered Blue Carbon ecosystems in the future, once these gaps are addressed.},
author = {Lovelock, Catherine E. and Duarte, Carlos M.},
doi = {10.1098/rsbl.2018.0781},
issn = {1744-9561},
journal = {Biology Letters},
month = {mar},
number = {3},
pages = {20180781},
title = {{Dimensions of Blue Carbon and emerging perspectives}},
url = {https://royalsocietypublishing.org/doi/10.1098/rsbl.2018.0781},
volume = {15},
year = {2019}
}
@article{Lovenduski2019b,
author = {Lovenduski, Nicole S. and Yeager, Stephen G. and Lindsay, Keith and Long, Matthew C.},
doi = {10.5194/esd-10-45-2019},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {jan},
number = {1},
pages = {45--57},
title = {{Predicting near-term variability in ocean carbon uptake}},
url = {https://www.earth-syst-dynam.net/10/45/2019/},
volume = {10},
year = {2019}
}
@article{Lovenduski2019c,
author = {Lovenduski, Nicole S and Bonan, Gordon B and Yeager, Stephen G and Lindsay, Keith and Lombardozzi, Danica L},
doi = {10.1088/1748-9326/ab5c55},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {dec},
number = {12},
pages = {124074},
title = {{High predictability of terrestrial carbon fluxes from an initialized decadal prediction system}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/ab5c55},
volume = {14},
year = {2019}
}
@article{Lowe2018,
abstract = {A number of studies have examined the size of the allowable global cumulative carbon budget compatible with limiting twenty-first century global average temperature rise to below 2°C and below 1.5°C relative to pre-industrial levels. These estimates of cumulative emissions have a number of uncertainties including those associated with the climate sensitivity and the global carbon cycle. Although the IPCC fifth assessment report contained information on a range of Earth system feedbacks, such as carbon released by thawing of permafrost or methane production by wetlands as a result of climate change, the impact of many of these Earth system processes on the allowable carbon budgets remains to be quantified. Here, we make initial estimates to show that the combined impact from typically unrepresented Earth system processes may be important for the achievability of limiting warming to 1.5°C or 2°C above pre-industrial levels. The size of the effects range up to around a 350 GtCO2budget reduction for a 1.5°C warming limit and around a 500 GtCO2reduction for achieving a warming limit of 2°C. Median estimates for the extra Earth system forcing lead to around 100 GtCO2and 150 GtCO2, respectively, for the two warming limits. Our estimates are equivalent to several years of anthropogenic carbon dioxide emissions at present rates. In addition to the likely reduction of the allowable global carbon budgets, the extra feedbacks also bring forward the date at which a given warming threshold is likely to be exceeded for a particular emission pathway.This article is part of the theme issue 'The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.},
author = {Lowe, Jason A. and Bernie, Daniel},
doi = {10.1098/rsta.2017.0263},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
keywords = {Carbon budget,Climate sensitivity,Earth system processes,Mitigation},
month = {may},
number = {2119},
pages = {20170263},
pmid = {29610375},
title = {{The impact of Earth system feedbacks on carbon budgets and climate response}},
url = {http://rsta.royalsocietypublishing.org/lookup/doi/10.1098/rsta.2017.0263},
volume = {376},
year = {2018}
}
@article{Lowe2019,
abstract = {Ocean acidification poses serious threats to coastal ecosystem services, yet few empirical studies have investigated how local ecological processes may modulate global changes of pH from rising atmospheric CO2. We quantified patterns of pH variability as a function of atmospheric CO2 and local physical and biological processes at 83 sites over 25 years in the Salish Sea and two NE Pacific estuaries. Mean seawater pH decreased significantly at −0.009 ± 0.0005 pH yr−1 (0.22 pH over 25 years), with spatially variable rates ranging up to 10 times greater than atmospheric CO2-driven ocean acidification. Dissolved oxygen saturation ({\%}DO) decreased by −0.24 ± 0.036{\%} yr−1, with site-specific trends similar to pH. Mean pH shifted from {\textless}7.6 in winter to {\textgreater}8.0 in summer concomitant to the seasonal shift from heterotrophy ({\%}DO {\textless} 100) to autotrophy ({\%}DO {\textgreater} 100) and dramatic shifts in aragonite saturation state critical to shell-forming organisms (probability of undersaturation was {\textgreater}80{\%} in winter, but {\textless}20{\%} in summer). {\%}DO overwhelmed the influence of atmospheric CO2, temperature and salinity on pH across scales. Collectively, these observations provide evidence that local ecosystem processes modulate ocean acidification, and support the adoption of an ecosystem perspective to ocean acidification and multiple stressors in productive aquatic habitats.},
author = {Lowe, Alexander T and Bos, Julia and Ruesink, Jennifer},
doi = {10.1038/s41598-018-37764-4},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {963},
title = {{Ecosystem metabolism drives pH variability and modulates long-term ocean acidification in the Northeast Pacific coastal ocean}},
url = {https://doi.org/10.1038/s41598-018-37764-4 http://www.nature.com/articles/s41598-018-37764-4},
volume = {9},
year = {2019}
}
@article{Lu2016,
abstract = {While recent findings based on satellite records indicate a positive trend in vegetation greenness over global drylands, the reasons remain elusive. We hypothesize that enhanced levels of atmospheric CO2 play an important role in the observed greening through the CO2 effect on plant water savings and consequent available soil water increases. Meta-analytic techniques were used to compare soil water content under ambient and elevated CO2 treatments across a range of climate regimes, vegetation types, soil textures and land management practices. Based on 1705 field measurements from 21 distinct sites, a consistent and statistically significant increase in the availability of soil water (11{\%}) was observed under elevated CO2 treatments in both drylands and non-drylands, with a statistically stronger response over drylands (17{\%} vs. 9{\%}). Given the inherent water limitation in drylands, it is suggested that the additional soil water availability is a likely driver of observed increases in vegetation greenness.},
author = {Lu, Xuefei and Wang, Lixin and McCabe, Matthew F.},
doi = {10.1038/srep20716},
issn = {20452322},
journal = {Scientific Reports},
number = {February},
pages = {1--7},
pmid = {26869389},
publisher = {Nature Publishing Group},
title = {{Elevated CO2 as a driver of global dryland greening}},
volume = {6},
year = {2016}
}
@article{Lucht2006,
abstract = {Dynamic Global Vegetation Models (DGVMs) compute the terrestrial carbon balance as well as the transient spatial distribution of vegetation. We study two scenarios of moderate and strong climate change (2.9 K and 5.3 K temperature increase over present) to investigate the spatial redistribution of major vegetation types and their carbon balance in the year 2100.},
annote = {added by A.Eliseev 25.01.2019},
author = {Lucht, Wolfgang and Schaphoff, Sibyll and Erbrecht, Tim and Heyder, Ursula and Cramer, Wolfgang},
doi = {10.1186/1750-0680-1-6},
issn = {1750-0680},
journal = {Carbon Balance and Management},
month = {dec},
number = {1},
pages = {6},
title = {{Terrestrial vegetation redistribution and carbon balance under climate change}},
url = {https://doi.org/10.1186/1750-0680-1-6 https://cbmjournal.biomedcentral.com/articles/10.1186/1750-0680-1-6},
volume = {1},
year = {2006}
}
@article{Luijendijk2020,
abstract = {The flow of fresh groundwater may provide substantial inputs of nutrients and solutes to the oceans. However, the extent to which hydrogeological parameters control groundwater flow to the world's oceans has not been quantified systematically. Here we present a spatially resolved global model of coastal groundwater discharge to show that the contribution of fresh groundwater accounts for {\~{}}0.6{\%} (0.004{\%}–1.3{\%}) of the total freshwater input and {\~{}}2{\%} (0.003{\%}–7.7{\%}) of the solute input for carbon, nitrogen, silica and strontium. However, the coastal discharge of fresh groundwater and nutrients displays a high spatial variability and for an estimated 26{\%} (0.4{\%}–39{\%}) of the world's estuaries, 17{\%} (0.3{\%}–31{\%}) of the salt marshes and 14{\%} (0.1–26{\%}) of the coral reefs, the flux of terrestrial groundwater exceeds 25{\%} of the river flux and poses a risk for pollution and eutrophication.},
author = {Luijendijk, Elco and Gleeson, Tom and Moosdorf, Nils},
doi = {10.1038/s41467-020-15064-8},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {1260},
title = {{Fresh groundwater discharge insignificant for the world's oceans but important for coastal ecosystems}},
url = {https://doi.org/10.1038/s41467-020-15064-8 http://www.nature.com/articles/s41467-020-15064-8},
volume = {11},
year = {2020}
}
@article{Lund2016,
author = {Lund, D. C. and Asimow, P. D. and Farley, K. A. and Rooney, T. O. and Seeley, E. and Jackson, E. W. and Durham, Z. M.},
doi = {10.1126/science.aad4296},
issn = {0036-8075},
journal = {Science},
month = {jan},
number = {6272},
pages = {478--482},
title = {{Enhanced East Pacific Rise hydrothermal activity during the last two glacial terminations}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.aad4296},
volume = {351},
year = {2016}
}
@article{Lundin2017,
abstract = {Restoration of wetlands is a high priority world-wide. Peat extraction areas can be restored by rewetting, however affecting the environment. It could be expected to turn the drained peat-cutover area from a source to a sink of most elements. This study examined effects of such rewetting on peat, hydrology and water chemistry over 15 years at two sites in Sweden; the nutrient-poor Porla peatland and the nutrient-rich V{\"{a}}stk{\"{a}}rr peatland. Rewetting caused minor changes to peat chemistry, but at the V{\"{a}}stk{\"{a}}rr site ammonium concentrations increased in superficial peat layers while nitrate decreased. In terms of hydrology, rewetting of the Porla site decreased annual runoff and both high and low discharges. Water pH at the Porla site stayed fairly stable, but at the V{\"{a}}stk{\"{a}}rr site pH, after an initial 4 years dip, gradually increased to higher values than before rewetting. Water colour and organic matter content were fairly stable, but slightly lower values were found after 15 years than in initial 4--5 years. The concentrations of base cations and of inorganic N were lower after rewetting, while total P was higher. However, these impacts could change from an initial phase as the wetlands in the long-term perspective develop into mires.},
author = {Lundin, Lars and Nilsson, Torbj{\"{o}}rn and Jordan, Sabine and Lode, Elve and Str{\"{o}}mgren, Monika},
doi = {10.1007/s11273-016-9524-9},
issn = {1572-9834},
journal = {Wetlands Ecology and Management},
number = {4},
pages = {405--419},
title = {{Impacts of rewetting on peat, hydrology and water chemical composition over 15 years in two finished peat extraction areas in Sweden}},
volume = {25},
year = {2017}
}
@article{Lunt2011,
abstract = {The early Eocene was marked by a series of abrupt warming events. Numerical modelling suggests that the events were the result of nonlinear interactions between orbital forcing, ocean circulation and the carbon cycle.},
author = {Lunt, Daniel J and Ridgwell, Andy and Sluijs, Appy and Zachos, James and Hunter, Stephen and Haywood, Alan},
doi = {10.1038/ngeo1266},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {11},
pages = {775--778},
title = {{A model for orbital pacing of methane hydrate destabilization during the Palaeogene}},
url = {https://doi.org/10.1038/ngeo1266},
volume = {4},
year = {2011}
}
@article{Luo2016,
abstract = {Soil carbon (C) is a critical component of Earth system models (ESMs) and its diverse representations are a major source of the large spread across models in the terrestrial C sink from the 3rd to 5th assessment reports of the Intergovernmental Panel on Climate Change (IPCC). Improving soil C projections is of a high priority for Earth system modeling in the future IPCC and other assessments. To achieve this goal, we suggest that (1) model structures should reflect real-world processes, (2) parameters should be calibrated to match model outputs with observations, and (3) external forcing variables should accurately prescribe the environmental conditions that soils experience. Firstly, most soil C cycle models simulate C input from litter production and C release through decomposition. The latter process has traditionally been represented by 1st-order decay functions, regulated primarily by temperature, moisture, litter quality, and soil texture. While this formulation well captures macroscopic SOC dynamics, better understanding is needed of their underlying mechanisms as related to microbial processes, depth-dependent environmental controls, and other processes that strongly affect soil C dynamics. Secondly, incomplete use of observations in model parameterization is a major cause of bias in soil C projections from ESMs. Optimal parameter calibration with both pool- and flux-based datasets through data assimilation is among the highest priorities for near-term research to reduce biases among ESMs. Thirdly, external variables are represented inconsistently among ESMs, leading to differences in modeled soil C dynamics. We recommend the implementation of traceability analyses to identify how external variables and model parameterizations influence SOC dynamics in different ESMs. Overall, projections of the terrestrial C sink can be substantially improved when reliable datasets are available to select the most representative model structure, constrain parameters, and prescribe forcing fields.},
author = {Luo, Yiqi and Ahlstr{\"{o}}m, Anders and Allison, Steven D and Batjes, Niels H and Brovkin, Victor and Carvalhais, Nuno and Chappell, Adrian and Ciais, Philippe and Davidson, Eric A and Finzi, Adien and Georgiou, Katerina and Guenet, Bertrand and Hararuk, Oleksandra and Harden, Jennifer W and He, Yujie and Hopkins, Francesca and Jiang, Lifen and Koven, Charlie and Jackson, Robert B and Jones, Chris D and Lara, Mark J and Liang, Junyi and McGuire, A David and Parton, William and Peng, Changhui and Randerson, James T and Salazar, Alejandro and Sierra, Carlos A and Smith, Matthew J and Tian, Hanqin and Todd-Brown, Katherine E O and Torn, Margaret and van Groenigen, Kees Jan and Wang, Ying Ping and West, Tristram O and Wei, Yaxing and Wieder, William R and Xia, Jianyang and Xu, Xiaofeng and Xu, Xiaofeng and Zhou, Tao},
doi = {10.1002/2015GB005239},
isbn = {1944-9224},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {jan},
number = {1},
pages = {40--56},
title = {{Toward more realistic projections of soil carbon dynamics by Earth system models}},
url = {http://dx.doi.org/10.1002/2015GB005239 http://doi.wiley.com/10.1002/2015GB005239},
volume = {30},
year = {2016}
}
@article{Lyons2019a,
abstract = {A hallmark of the rapid and massive release of carbon during the Palaeocene–Eocene Thermal Maximum is the global negative carbon isotope excursion. The delayed recovery of the carbon isotope excursion, however, indicates that CO2 inputs continued well after the initial rapid onset, although there is no consensus about the source of this secondary carbon. Here we suggest this secondary input might have derived partly from the oxidation of remobilized sedimentary fossil carbon. We measured the biomarker indicators of thermal maturation in shelf records from the US Mid-Atlantic coast, constructed biomarker mixing models to constrain the amount of fossil carbon in US Mid-Atlantic and Tanzania coastal records, estimated the fossil carbon accumulation rate in coastal sediments and determined the range of global CO2 release from fossil carbon reservoirs. This work provides evidence for an order of magnitude increase in fossil carbon delivery to the oceans that began {\~{}}10–20 kyr after the event onset and demonstrates that the oxidation of remobilized fossil carbon released between 102 and 104 PgC as CO2 during the body of the Palaeocene–Eocene Thermal Maximum. The estimated mass is sufficient to have sustained the elevated atmospheric CO2 levels required by the prolonged global carbon isotope excursion. Even after considering uncertainties in the sedimentation rates, these results indicate that the enhanced erosion, mobilization and oxidation of ancient sedimentary carbon contributed to the delayed recovery of the climate system for many thousands of years.},
author = {Lyons, Shelby L and Baczynski, Allison A and Babila, Tali L and Bralower, Timothy J and Hajek, Elizabeth A and Kump, Lee R and Polites, Ellen G and Self-Trail, Jean M and Trampush, Sheila M and Vornlocher, Jamie R and Zachos, James C and Freeman, Katherine H},
doi = {10.1038/s41561-018-0277-3},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {1},
pages = {54--60},
title = {{Palaeocene–Eocene Thermal Maximum prolonged by fossil carbon oxidation}},
url = {https://doi.org/10.1038/s41561-018-0277-3},
volume = {12},
year = {2019}
}
@article{Maavara2019,
author = {Maavara, Taylor and Lauerwald, Ronny and Laruelle, Goulven G. and Akbarzadeh, Zahra and Bouskill, Nicholas J. and {Van Cappellen}, Philippe and Regnier, Pierre},
doi = {10.1111/gcb.14504},
issn = {13541013},
journal = {Global Change Biology},
month = {feb},
number = {2},
pages = {473--488},
title = {{Nitrous oxide emissions from inland waters: Are IPCC estimates too high?}},
url = {http://doi.wiley.com/10.1111/gcb.14504},
volume = {25},
year = {2019}
}
@article{MacDougall2020,
abstract = {Abstract. The Zero Emissions Commitment (ZEC) is the change in global mean temperature expected to occur following the cessation of net CO2 emissions and as such is a critical parameter for calculating the remaining carbon budget. The Zero Emissions Commitment Model Intercomparison Project (ZECMIP) was established to gain a better understanding of the potential magnitude and sign of ZEC, in addition to the processes that underlie this metric. A total of 18 Earth system models of both full and intermediate complexity participated in ZECMIP. All models conducted an experiment where atmospheric CO2 concentration increases exponentially until 1000 PgC has been emitted. Thereafter emissions are set to zero and models are configured to allow free evolution of atmospheric CO2 concentration. Many models conducted additional second-priority simulations with different cumulative emission totals and an alternative idealized emissions pathway with a gradual transition to zero emissions. The inter-model range of ZEC 50 years after emissions cease for the 1000 PgC experiment is −0.36 to 0.29 ∘C, with a model ensemble mean of −0.07 ∘C, median of −0.05 ∘C, and standard deviation of 0.19 ∘C. Models exhibit a wide variety of behaviours after emissions cease, with some models continuing to warm for decades to millennia and others cooling substantially. Analysis shows that both the carbon uptake by the ocean and the terrestrial biosphere are important for counteracting the warming effect from the reduction in ocean heat uptake in the decades after emissions cease. This warming effect is difficult to constrain due to high uncertainty in the efficacy of ocean heat uptake. Overall, the most likely value of ZEC on multi-decadal timescales is close to zero, consistent with previous model experiments and simple theory.},
author = {MacDougall, Andrew H. and Fr{\"{o}}licher, Thomas L. and Jones, Chris D. and Rogelj, Joeri and Matthews, H. Damon and Zickfeld, Kirsten and Arora, Vivek K. and Barrett, Noah J. and Brovkin, Victor and Burger, Friedrich A. and Eby, Micheal and Eliseev, Alexey V. and Hajima, Tomohiro and Holden, Philip B. and Jeltsch-Th{\"{o}}mmes, Aurich and Koven, Charles and Mengis, Nadine and Menviel, Laurie and Michou, Martine and Mokhov, Igor I. and Oka, Akira and Schwinger, J{\"{o}}rg and S{\'{e}}f{\'{e}}rian, Roland and Shaffer, Gary and Sokolov, Andrei and Tachiiri, Kaoru and Tjiputra, Jerry and Wiltshire, Andrew and Ziehn, Tilo},
doi = {10.5194/bg-17-2987-2020},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jun},
number = {11},
pages = {2987--3016},
publisher = {Copernicus GmbH},
title = {{Is there warming in the pipeline? A multi-model analysis of the Zero Emissions Commitment from CO2}},
url = {https://bg.copernicus.org/articles/17/2987/2020/},
volume = {17},
year = {2020}
}
@article{MacDougall2017a,
abstract = {Virtually all Earth system models (ESM) show a near proportional relationship between cumulative emissions of CO2 and change in global mean temperature, a relationship which is independent of the emissions pathway taken to reach a cumulative emissions total. The relationship, which has been named the Transient Climate Response to Cumulative CO2 Emissions (TCRE), gives rise to the concept of a ‘carbon budget'. That is, a finite amount of carbon that can be burnt whilst remaining below some chosen global temperature change threshold, such as the 2.0 °C target set by the Paris Agreement. Here we show that the path-independence of TCRE arises from the partitioning ratio of anthropogenic carbon between the ocean and the atmosphere being almost the same as the partitioning ratio of enhanced radiative forcing between the ocean and space. That these ratios are so close in value is a coincidence unique to CO2. The simple model used here is underlain by many assumptions and simplifications but does reproduce key aspects of the climate system relevant to the path-independence of carbon budgets. Our results place TCRE and carbon budgets on firm physical foundations and therefore help validate the use of these metrics for climate policy.},
author = {MacDougall, Andrew H.},
doi = {10.1038/s41598-017-10557-x},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {10373},
pmid = {28871166},
publisher = {Springer US},
title = {{The oceanic origin of path-independent carbon budgets}},
url = {http://dx.doi.org/10.1038/s41598-017-10557-x http://www.nature.com/articles/s41598-017-10557-x},
volume = {7},
year = {2017}
}
@article{MacDougall2017,
abstract = {AbstractAn emergent property of most Earth system models is a near linear relationship between cumulative emission of CO2 and change in global near surface temperature. This relationship, which has been named the transient climate response to cumulative CO2 emissions (TCRE), implies a finite budget of fossil fuel carbon that can be burnt over all time consistent with a chosen temperature change target. Carbon budgets are inversely proportional to the value of TCRE and are therefore sensitive to the uncertainty in TCRE. Here we have used a perturbed physics approach with an Earth system model of intermediate complexity to assess the uncertainty in the TCRE that arises from uncertainty in the rate of transient temperature change and the effect of this uncertainty on carbon cycle feedbacks. The experiments are conducted using an idealized 1{\%} per year increase in CO2 concentration. Additionally we have emulated the temperature output of 23 Climate Model Intercomparison Project Phase Five (CMIP5) models. The e...},
author = {MacDougall, Andrew H. and Swart, Neil C. and Knutti, Reto},
doi = {10.1175/JCLI-D-16-0205.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jan},
number = {2},
pages = {813--827},
title = {{The uncertainty in the transient climate response to cumulative CO2 emissions arising from the uncertainty in physical climate parameters}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0205.1},
volume = {30},
year = {2017}
}
@article{MacDougall2015,
abstract = {AbstractThe transient climate response to cumulative CO2 emissions (TCRE) is a useful metric of climate warming that directly relates the cause of climate change (cumulative carbon emissions) to the most used index of climate change (global mean near surface temperature change). In this manuscript analytical reasoning is used to investigate why TCRE is near constant over a range of cumulative emissions up to 2000 Pg of carbon. In addition, a climate model of intermediate complexity, forced with a constant flux of CO2 emissions, is used to explore the effect of terrestrial carbon cycle feedback strength on TCRE. The analysis reveals that TCRE emerges from the diminishing radiative forcing from CO2 per unit mass being compensated for by the diminishing ability of the ocean to take up heat and carbon. The relationship is maintained as long as the ocean uptake of carbon, which is simulated to be a function of CO2 emissions rate, dominates changes in the airborne fraction of carbon. Strong terrestrial carbon c...},
author = {MacDougall, Andrew H. and Friedlingstein, Pierre},
doi = {10.1175/JCLI-D-14-00036.1},
isbn = {10.1175/JCLI-D-14-00036.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {may},
number = {10},
pages = {4217--4230},
title = {{The origin and limits of the near proportionality between climate warming and cumulative CO2 emissions}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-14-00036.1},
volume = {28},
year = {2015}
}
@article{MacDougall2016,
abstract = {The transient climate response to cumulative CO2 emissions (TCRE) is a metric of climate change that directly relates the primary cause of climate change (cumulative CO2 emissions) to global mean temperature change. The metric was developed once researchers noticed that the cumulative CO2 versus temperature change curve was nearly linear for almost all Earth system model output. Here, recent literature on the origin, limits, and value of TCRE is reviewed. TCRE appears to emerge from the diminishing radiative forcing per unit mass of atmospheric CO2 being compensated by diminishing efficiency of ocean heat uptake and the modulation of airborne fraction of carbon by ocean processes. The best estimate of the value of TCRE is between 0.8 to 2.5 K EgC−1. Overall, TCRE has been shown to be a conceptually simple and robust metric of climate warming with many applications in formulating climate policy.},
author = {MacDougall, Andrew H.},
doi = {10.1007/s40641-015-0030-6},
issn = {2198-6061},
journal = {Current Climate Change Reports},
keywords = {carbon budget,ccr,climate change,tcre},
month = {mar},
number = {1},
pages = {39--47},
title = {{The Transient Response to Cumulative CO2 Emissions: a Review}},
url = {http://link.springer.com/10.1007/s40641-015-0030-6},
volume = {2},
year = {2016}
}
@article{MacDougall2015a,
author = {MacDougall, Andrew H and Zickfeld, Kirsten and Knutti, Reto and Matthews, H Damon},
doi = {10.1088/1748-9326/10/12/125003},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {dec},
number = {12},
pages = {125003},
publisher = {IOP Publishing},
title = {{Sensitivity of carbon budgets to permafrost carbon feedbacks and non-CO2 forcings}},
url = {http://stacks.iop.org/1748-9326/10/i=12/a=125003?key=crossref.0500b56b16f814bd29bef9c1b908cd5b},
volume = {10},
year = {2015}
}
@article{MacDougall2016a,
abstract = {Abstract. The soils of the northern hemispheric permafrost region are estimated to contain 1100 to 1500 Pg of carbon. A substantial fraction of this carbon has been frozen and therefore protected from microbial decay for millennia. As anthropogenic climate warming progresses much of this permafrost is expected to thaw. Here we conduct perturbed model experiments on a climate model of intermediate complexity, with an improved permafrost carbon module, to estimate with formal uncertainty bounds the release of carbon from permafrost soils by the year 2100 and 2300 CE. We estimate that by year 2100 the permafrost region may release between 56 (13 to 118) Pg C under Representative Concentration Pathway (RCP) 2.6 and 102 (27 to 199) Pg C under RCP 8.5, with substantially more to be released under each scenario by the year 2300. Our analysis suggests that the two parameters that contribute most to the uncertainty in the release of carbon from permafrost soils are the size of the non-passive fraction of the permafrost carbon pool and the equilibrium climate sensitivity. A subset of 25 model variants are integrated 8000 years into the future under continued RCP forcing. Under the moderate RCP 4.5 forcing a remnant near-surface permafrost region persists in the high Arctic, eventually developing a new permafrost carbon pool. Overall our simulations suggest that the permafrost carbon cycle feedback to climate change will make a significant contribution to climate change over the next centuries and millennia, releasing a quantity of carbon 3 to 54 {\%} of the cumulative anthropogenic total.},
author = {MacDougall, Andrew H. and Knutti, Reto},
doi = {10.5194/bg-13-2123-2016},
issn = {1726-4189},
journal = {Biogeosciences},
month = {apr},
number = {7},
pages = {2123--2136},
title = {{Projecting the release of carbon from permafrost soils using a perturbed parameter ensemble modelling approach}},
url = {https://bg.copernicus.org/articles/13/2123/2016/},
volume = {13},
year = {2016}
}
@article{MacDougall2016b,
author = {MacDougall, Andrew H. and Knutti, Reto},
doi = {10.1002/2016GL068964},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {jun},
number = {11},
pages = {5833--5840},
title = {{Enhancement of non-CO2 radiative forcing via intensified carbon cycle feedbacks}},
url = {http://doi.wiley.com/10.1002/2016GL068964},
volume = {43},
year = {2016}
}
@article{MacFarlingMeure2006,
abstract = {New measurements of atmospheric greenhouse gas concentrations in ice from Law Dome, Antarctica reproduce published Law Dome CO2 and CH4 records, extend them back to 2000 years BP, and include N2O. They have very high air age resolution, data density and measurement precision. Firn air measurements span the past 65 years and overlap with the ice core and direct atmospheric observations. Major increases in CO2, CH4 and N2O concentrations during the past 200 years followed a period of relative stability beforehand. Decadal variations during the industrial period include the stabilization of CO2 and slowing of CH4 and N2O growth in the 1940s and 1950s. Variations of up to 10 ppm CO2, 40 ppb CH4 and 10 ppb N2O occurred throughout the preindustrial period. Methane concentrations grew by 100 ppb from AD 0 to 1800, possibly due to early anthropogenic emissions.},
author = {{MacFarling Meure}, C. and Etheridge, D. and Trudinger, C. and Steele, P. and Langenfelds, R. and van Ommen, T. and Smith, A. and Elkins, J.},
doi = {10.1029/2006GL026152},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {jul},
number = {14},
pages = {L14810},
publisher = {Wiley-Blackwell},
title = {{Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP}},
url = {http://doi.wiley.com/10.1029/2006GL026152 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2006GL026152},
volume = {33},
year = {2006}
}
@article{MacMartin2014a,
abstract = { Solar geoengineering has been suggested as a tool that might reduce damage from anthropogenic climate change. Analysis often assumes that geoengineering would be used to maintain a constant global mean temperature. Under this scenario, geoengineering would be required either indefinitely (on societal time scales) or until atmospheric CO2 concentrations were sufficiently reduced. Impacts of climate change, however, are related to the rate of change as well as its magnitude. We thus describe an alternative scenario in which solar geoengineering is used only to constrain the rate of change of global mean temperature; this leads to a finite deployment period for any emissions pathway that stabilizes global mean temperature. The length of deployment and amount of geoengineering required depends on the emissions pathway and allowable rate of change, e.g. in our simulations, reducing the maximum approximately 0.3°C per decade rate of change in an RCP 4.5 pathway to 0.1°C per decade would require geoengineering for 160 years; under RCP 6.0, the required time nearly doubles. We demonstrate that feedback control can limit rates of change in a climate model. Finally, we note that a decision to terminate use of solar geoengineering does not automatically imply rapid temperature increases: feedback could be used to limit rates of change in a gradual phase-out. },
author = {MacMartin, Douglas G and Caldeira, Ken and Keith, David W},
doi = {10.1098/rsta.2014.0134},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
number = {2031},
pages = {20140134},
title = {{Solar geoengineering to limit the rate of temperature change}},
volume = {372},
year = {2014}
}
@article{Macreadie2019,
author = {Macreadie, Peter I. and Anton, Andrea and Raven, John A. and Beaumont, Nicola and Connolly, Rod M. and Friess, Daniel A. and Kelleway, Jeffrey J. and Kennedy, Hilary and Kuwae, Tomohiro and Lavery, Paul S. and Lovelock, Catherine E. and Smale, Dan A. and Apostolaki, Eugenia T. and Atwood, Trisha B. and Baldock, Jeff and Bianchi, Thomas S. and Chmura, Gail L. and Eyre, Bradley D. and Fourqurean, James W. and Hall-Spencer, Jason M. and Huxham, Mark and Hendriks, Iris E. and Krause-Jensen, Dorte and Laffoley, Dan and Luisetti, Tiziana and Marb{\`{a}}, N{\'{u}}ria and Masque, Pere and McGlathery, Karen J. and Megonigal, J. Patrick and Murdiyarso, Daniel and Russell, Bayden D. and Santos, Rui and Serrano, Oscar and Silliman, Brian R. and Watanabe, Kenta and Duarte, Carlos M.},
doi = {10.1038/s41467-019-11693-w},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {3998},
title = {{The future of Blue Carbon science}},
url = {http://www.nature.com/articles/s41467-019-11693-w},
volume = {10},
year = {2019}
}
@article{Mahowald2017,
author = {Mahowald, Natalie M. and Scanza, Rachel and Brahney, Janice and Goodale, Christine L. and Hess, Peter G. and Moore, J. Keith and Neff, Jason},
doi = {10.1007/s40641-017-0056-z},
issn = {2198-6061},
journal = {Current Climate Change Reports},
month = {mar},
number = {1},
pages = {16--31},
publisher = {Springer International Publishing},
title = {{Aerosol deposition impacts on land and ocean carbon cycles}},
url = {http://link.springer.com/10.1007/s40641-017-0056-z},
volume = {3},
year = {2017}
}
@article{MALAKHOVA2020103249,
abstract = {Temperature and sea level changes in the Pleistocene are uncertain. This leads to uncertainty in the associated response of the thermal state of the subsea sediments. We quantified the upper bound of the latter uncertainty in idealised simulations with a model for thermophysical processes in the sediments. At the coast and at the shallow and intermediate–depth shelves and except during relatively isolated time intervals, this bound for permafrost base depth and for the methane hydrate stability zone (MHSZ) characteristics (depth of its bottom boundary and its thickness) is ≤45{\%} provided that the geothermal heat flux (GHF) is not larger than 80mWm−2. These values are much smaller than the uncertainty metrics for the forcing data, which are typically ≥65{\%}. However, for the intermediate shelf with a larger geothermal heat flux and for the deep shelf irrespective of GHF, different forcing time series may even lead to qualitatively different behaviour of the sediment thermophysical characteristics. We found that prescription of sea level changes plays a crucial role in uncertainty of the simulated subsea permafrost and MHSZ in the deep shelf sediments. In addition, we also quantified uncertainty for estimated apparent response time scales. The relative uncertainty for permafrost base depth and hydrate stability zone thickness time scales is ≤20{\%} for most cases. We found no systematic dependence of our results on accounting for millennium–scale temperature variability provided that timescales of the order of 104yr are resolved by forcing datasets.},
author = {Malakhova, Valentina V and Eliseev, Alexey V},
doi = {10.1016/j.gloplacha.2020.103249},
issn = {0921-8181},
journal = {Global and Planetary Change},
keywords = {Glacial cycles,Paleoreconstructions,Response timescales,Subsea methane hydrates,Subsea permafrost},
pages = {103249},
title = {{Uncertainty in temperature and sea level datasets for the Pleistocene glacial cycles: Implications for thermal state of the subsea sediments}},
url = {http://www.sciencedirect.com/science/article/pii/S0921818120301405},
volume = {192},
year = {2020}
}
@article{Malakhova2017,
abstract = {Climate warming may lead to degradation of the subsea permafrost developed during Pleistocene glaciations and release methane from the hydrates, which are stored in this permafrost. It is important to quantify time scales at which this release is plausible. While, in principle, such time scale might be inferred from paleoarchives, this is hampered by considerable uncertainty associated with paleodata. In the present paper, to reduce such uncertainty, one-dimensional simulations with a model for thermal state of subsea sediments forced by the data obtained from the ice core reconstructions are performed. It is shown that heat propagates in the sediments with a time scale of ∼ 10–20 kyr. This time scale is longer than the present interglacial and is determined by the time needed for heat penetration in the unfrozen part of thick sediments. We highlight also that timings of shelf exposure during oceanic regressions and flooding during transgressions are important for simulating thermal state of the sediments and methane hydrates stability zone (HSZ). These timings should be resolved with respect to the contemporary shelf depth (SD). During glacial cycles, the temperature at the top of the sediments is a major driver for moving the HSZ vertical boundaries irrespective of SD. In turn, pressure due to oceanic water is additionally important for SD ≥ 50 m. Thus, oceanic transgressions and regressions do not instantly determine onsets of HSZ and/or its disappearance. Finally, impact of initial conditions in the subsea sediments is lost after ∼ 100 kyr. Our results are moderately sensitive to intensity of geothermal heat flux.},
author = {Malakhova, Valentina V. and Eliseev, Alexey V.},
doi = {10.1016/j.gloplacha.2017.08.007},
issn = {09218181},
journal = {Global and Planetary Change},
keywords = {Glacial cycles,Subsea methane hydrates,Subsea permafrost},
month = {oct},
pages = {18--25},
title = {{The role of heat transfer time scale in the evolution of the subsea permafrost and associated methane hydrates stability zone during glacial cycles}},
url = {https://www.sciencedirect.com/science/article/pii/S0921818117301273?via{\%}3Dihub https://linkinghub.elsevier.com/retrieve/pii/S0921818117301273},
volume = {157},
year = {2017}
}
@article{Malhi2018,
abstract = {One contribution of 22 to a discussion meeting issue 'The impact of the 2015/2016 El Ni{\~{n}}o on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.},
author = {Malhi, Yadvinder and Rowland, Lucy and Arag{\~{a}}o, Luiz E. O. C. and Fisher, Rosie A.},
doi = {10.1098/rstb.2017.0298},
issn = {0962-8436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
month = {nov},
number = {1760},
pages = {20170298},
title = {{New insights into the variability of the tropical land carbon cycle from the El Ni{\~{n}}o of 2015/2016}},
url = {http://rstb.royalsocietypublishing.org/lookup/doi/10.1098/rstb.2017.0298},
volume = {373},
year = {2018}
}
@article{Manizza2012,
abstract = {ABSTRACTThe seasonal dynamics of the air–sea gas flux of oxygen (O2) are controlled by multiple processes occurring simultaneously. Previous studies showed how to separate the thermal component from the total O2 flux to quantify the residual oxygen flux due to biological processes. However, this biological signal includes the effect of both net euphotic zone production (NEZP) and subsurface water ventilation. To help understand and separate these two components, we use a large-scale ocean general circulation model (OGCM), globally configured, and coupled to a biogeochemical model. The combined model implements not only the oceanic cycle of O2 but also the cycles of nitrous oxide (N2O), argon (Ar) and nitrogen (N2). For this study, we apply a technique to distinguish the fluxes of O2 driven separately by thermal forcing, NEZP, and address the role of ocean ventilation by carrying separate O2 components in the model driven by solubility, NEZP and ventilation. Model results show that the ventilation componen...},
author = {Manizza, Manfredi and Keeling, Ralph F. and Nevison, Cynthia D.},
doi = {10.3402/tellusb.v64i0.18429},
issn = {1600-0889},
journal = {Tellus B: Chemical and Physical Meteorology},
month = {jan},
number = {1},
pages = {18429},
publisher = {Taylor {\&} Francis},
title = {{On the processes controlling the seasonal cycles of the air–sea fluxes of O2 and N2O: A modelling study}},
url = {https://www.tandfonline.com/doi/full/10.3402/tellusb.v64i0.18429},
volume = {64},
year = {2012}
}
@article{Mankin2019,
abstract = {Plants are expected to generate more global-scale runoff under increasing atmospheric carbon dioxide concentrations through their influence on surface resistance to evapotranspiration. Recent studies using Earth System Models from phase 5 of the Coupled Model Intercomparison Project ostensibly reaffirm this result, further suggesting that plants will ameliorate the dire reductions in water availability projected by other studies that use aridity metrics. Here we complicate this narrative by analysing the change in precipitation partitioning to plants, runoff and storage in multiple Earth system models under both high carbon dioxide concentrations and warming. We show that projected plant responses directly reduce future runoff across vast swaths of North America, Europe and Asia because bulk canopy water demands increase with additional vegetation growth and longer and warmer growing seasons. These runoff declines occur despite increased surface resistance to evapotranspiration and vegetation total water use efficiency, even in regions with increasing or unchanging precipitation. We demonstrate that constraining the large uncertainty in the multimodel ensemble with regional-scale observations of evapotranspiration partitioning strengthens these results. We conclude that terrestrial vegetation plays a large and unresolved role in shaping future regional freshwater availability, one that will not ubiquitously ameliorate future warming-driven surface drying.},
author = {Mankin, Justin S. and Seager, Richard and Smerdon, Jason E. and Cook, Benjamin I. and Williams, A. Park},
doi = {10.1038/s41561-019-0480-x},
issn = {17520908},
journal = {Nature Geoscience},
number = {12},
pages = {983--988},
publisher = {Springer US},
title = {{Mid-latitude freshwater availability reduced by projected vegetation responses to climate change}},
url = {http://dx.doi.org/10.1038/s41561-019-0480-x},
volume = {12},
year = {2019}
}
@article{Mao2016,
abstract = {Significant land greening in the northern extratropical latitudes (NEL) has been documented through satellite observations during the past three decades1, 2, 3, 4, 5. This enhanced vegetation growth has broad implications for surface energy, water and carbon budgets, and ecosystem services across multiple scales6, 7, 8. Discernible human impacts on the Earth's climate system have been revealed by using statistical frameworks of detection–attribution9, 10, 11. These impacts, however, were not previously identified on the NEL greening signal, owing to the lack of long-term observational records, possible bias of satellite data, different algorithms used to calculate vegetation greenness, and the lack of suitable simulations from coupled Earth system models (ESMs). Here we have overcome these challenges to attribute recent changes in NEL vegetation activity. We used two 30-year-long remote-sensing-based leaf area index (LAI) data sets12, 13, simulations from 19 coupled ESMs with interactive vegetation, and a formal detection and attribution algorithm14, 15. Our findings reveal that the observed greening record is consistent with an assumption of anthropogenic forcings, where greenhouse gases play a dominant role, but is not consistent with simulations that include only natural forcings and internal climate variability. These results provide the first clear evidence of a discernible human fingerprint on physiological vegetation changes other than phenology and range shifts11.},
author = {Mao, Jiafu and Ribes, Aur{\'{e}}lien and Yan, Binyan and Shi, Xiaoying and Thornton, Peter E. and S{\'{e}}f{\'{e}}rian, Roland and Ciais, Philippe and Myneni, Ranga B. and Douville, Herv{\'{e}} and Piao, Shilong and Zhu, Zaichun and Dickinson, Robert E. and Dai, Yongjiu and Ricciuto, Daniel M. and Jin, Mingzhou and Hoffman, Forrest M. and Wang, Bin and Huang, Mengtian and Lian, Xu},
doi = {10.1038/nclimate3056},
isbn = {1758-678X},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {oct},
number = {10},
pages = {959--963},
title = {{Human-induced greening of the northern extratropical land surface}},
url = {https://www.nature.com/articles/nclimate3056 http://www.nature.com/articles/nclimate3056},
volume = {6},
year = {2016}
}
@article{Marcott2014a,
abstract = {Global climate and the concentration of atmospheric carbon dioxide (CO2) are correlated over recent glacial cycles. The combination of processes responsible for a rise in atmospheric CO2 at the last glacial termination (23,000 to 9,000 years ago), however, remains uncertain. Establishing the timing and rate of CO2 changes in the past provides critical insight into the mechanisms that influence the carbon cycle and helps put present and future anthropogenic emissions in context. Here we present CO2 and methane (CH4) records of the last deglaciation from a new high-accumulation West Antarctic ice core with unprecedented temporal resolution and precise chronology. We show that although low-frequency CO2 variations parallel changes in Antarctic temperature, abrupt CO2 changes occur that have a clear relationship with abrupt climate changes in the Northern Hemisphere. A significant proportion of the direct radiative forcing associated with the rise in atmospheric CO2 occurred in three sudden steps, each of 10 to 15 parts per million. Every step took place in less than two centuries and was followed by no notable change in atmospheric CO2 for about 1,000 to 1,500 years. Slow, millennial-scale ventilation of Southern Ocean CO2-rich, deep-ocean water masses is thought to have been fundamental to the rise in atmospheric CO2 associated with the glacial termination, given the strong covariance of CO2 levels and Antarctic temperatures. Our data establish a contribution from an abrupt, centennial-scale mode of CO2 variability that is not directly related to Antarctic temperature. We suggest that processes operating on centennial timescales, probably involving the Atlantic meridional overturning circulation, seem to be influencing global carbon-cycle dynamics and are at present not widely considered in Earth system models.},
author = {Marcott, Shaun A. and Bauska, Thomas K. and Buizert, Christo and Steig, Eric J. and Rosen, Julia L. and Cuffey, Kurt M. and Fudge, T. J. and Severinghaus, Jeffery P. and Ahn, Jinho and Kalk, Michael L. and McConnell, Joseph R. and Sowers, Todd and Taylor, Kendrick C. and White, James W. C. and Brook, Edward J.},
doi = {10.1038/nature13799},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7524},
pages = {616--619},
pmid = {25355363},
title = {{Centennial-scale changes in the global carbon cycle during the last deglaciation}},
url = {http://www.nature.com/articles/nature13799},
volume = {514},
year = {2014}
}
@article{Marshall2015,
author = {Marshall, John and Scott, Jeffery R. and Armour, Kyle C. and Campin, J.-M. and Kelley, Maxwell and Romanou, Anastasia},
doi = {10.1007/s00382-014-2308-0},
issn = {0930-7575},
journal = {Climate Dynamics},
month = {apr},
number = {7-8},
pages = {2287--2299},
title = {{The ocean's role in the transient response of climate to abrupt greenhouse gas forcing}},
url = {http://link.springer.com/10.1007/s00382-014-2308-0},
volume = {44},
year = {2015}
}
@article{Martinez-Boti2015a,
abstract = {Theory and climate modelling suggest that the sensitivity of Earth's climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO 2) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth's climate sensitivity to CO 2-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleisto-cene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice-albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO 2 levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO 2. Since the start of the industrial revolution, the concentration of atmospheric CO 2 (and other greenhouse gases) has increased dramatically (from ,280 to ,400 parts per million) 1. It has been known for over 100 years that changes in greenhouse gas concentration will cause the surface temperature of Earth to vary 2. A wide range of observations reveals that the sensitivity of Earth's surface temperature to radiative forcing amounts to ,3 K warming per doubling of atmospheric CO 2 concentration (with a 66{\%} confidence range of 1.5-4.5 K; see refs 1 and 3), caused by direct radiative forcing by CO 2 plus the action of a number of fast-acting positive feedback mechanisms, mainly related to atmospheric water vapour content and sea-ice and cloud albedo. Uncertainty in the magnitude of these feedbacks confounds our ability to determine the exact equilibrium climate sensitivity (ECS; the equilibrium global temperature change for a doubling of CO 2 on timescales of about a century, after all 'fast' feedbacks have had time to operate; see ref. 3 for more detail). Although the likely range of values for ECS is 1.5-4.5 K per CO 2 doubling, there is a small but finite possibility that climate sensitivity may exceed 5 K (see ref. 1). Understanding the likely value of ECS clearly has important implications for the magnitude, eventual impact and potential mitigation of future climate change. Any long-range forecast of global temperature (that is, beyond the next 100 years) must also consider the possibility that ECS could depend on the background state of the climate 4,5. That is, in a warmer world, some feedbacks that determine ECS could become more efficient and/or new feedbacks could become active to give additional warmth for a given change in radiative forcing (such as those relating to methane cycling 6 , atmospheric water vapour concentrations 5,7,8 , in addition to changes in the relative opacity of CO 2 to long-wave radiation 5,9). One approach to identify whether ECS depends on the climate background state is to reconstruct ECS during periods in the geological past when Earth was warmer than today. The Pliocene (2.6-5.3 million years (Myr) ago) is one such time, with the warmest intervals between 3.0 Myr and 3.3 Myr ago about 3 K globally warmer than pre-industrial times 10,11 ; the mean sea level was 12-32 m above the present level 12,13. Although most of this warmth is commonly ascribed to increased atmospheric CO 2 levels 14 , it has been suggested that simple comparisons of the observed temperature change in the geological record with the climate forcing from CO 2 alone are unable to constrain ECS 10. Instead, a parameter termed the Earth system sensitivity (ESS) is defined, as the change in global temperature for a doubling of CO 2 once both fast and slow feedbacks have acted and the whole Earth system has reached equilibrium. (In contrast, ECS excludes the slow feedbacks; for a discussion of fast versus slow feedbacks, see ref. 3.) The most important slow feedbacks are those related to ice-albedo and vegetation-albedo changes. Because of these slow feedbacks, Pliocene ESS is thought to have been ,50{\%} higher than ECS 10,15 , with some existing geological data suggesting a Pliocene ESS range of 7-10 K per CO 2 doubling 16 , which greatly exceeds a modern ESS estimate of ,4 K per CO 2 doubling 10. If ECS was similarly enhanced, then that would imply that either extra positive fast feedbacks operated, or that existing positive fast feedbacks were more efficient, thus increasing the temperature response for a given level of CO 2 forcing. Understanding past climate sensitivity depends critically on the accuracy of the CO 2 data used. Despite a tendency towards increased agreement between different CO 2 proxies 17 , individual estimates of the partial pressure of CO 2 (p CO2) for the Pliocene still range from ,190 matm to ,440 matm (Fig. 1a, b) and there is little coherence in the trends described by the various techniques (Fig. 1a, b). This hinders any effort to accurately},
author = {Mart{\'{i}}nez-Bot{\'{i}}, M A and Foster, G L and Chalk, T B and Rohling, E J and Sexton, P F and Lunt, D J and Pancost, R D and Badger, M P S and Schmidt, D. N.},
doi = {10.1038/nature14145},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7537},
pages = {49--54},
title = {{Plio-Pleistocene climate sensitivity evaluated using high-resolution CO2 records}},
url = {https://www.nature.com/articles/nature14145 http://www.nature.com/articles/nature14145},
volume = {518},
year = {2015}
}
@article{Martinez-Boti2015b,
abstract = {Atmospheric CO2 fluctuations over glacial–interglacial cycles remain a major challenge to our understanding of the carbon cycle and the climate system. Leading hypotheses put forward to explain glacial– interglacial atmospheric CO2 variations invoke changes in deep-ocean carbon storage, probably modulated by processes in the Southern Ocean, where much of the deep ocean is ventilated. A central aspect of such models is that, during deglaciations, an isolated glacial deep ocean carbon reservoir is reconnected with the atmosphere, driving the atmospheric CO2 rise observed in ice-core records. However, direct documentation of changes in surface ocean carbon contentand the associated transfer of carbon to the atmosphere during deglaciations has been hindered by the lack of proxy reconstructions that unambiguously reflect the oceanic carbonate system. Radiocarbon activity tracks changes in ocean ventilation, but not in ocean carbon content, whereas proxies that record increased deglacial upwelling do not constrain the proportion of upwelled carbon that is degassed relative to that which is taken up by the biological pump. Here we apply the boron isotope pH proxy in planktic foraminifera to two sediment cores from the sub-Antarctic, Atlantic and the eastern equatorial Pacific as a more direct tracer of oceanic CO2 outgassing. We show that surface waters at both locations, which partly derive from deep water upwelled in the Southern Ocean, became a significant source of carbon to the atmosphere during the last deglaciation, when the concentration of atmospheric CO2 was increasing. This oceanic CO2 outgassing supports the view that the ventilation of a deep-ocean carbon reservoir in the Southern Ocean had a key role in the deglacial CO2 rise, although our results allow for the possibility that processes operating in other regions may also have been important for the glacial–interglacial ocean–atmosphere exchange of carbon.},
author = {Mart{\'{i}}nez-Bot{\'{i}}, M. A. and Marino, G. and Foster, G. L. and Ziveri, P. and Henehan, M. J. and Rae, J. W. B. and Mortyn, P. G. and Vance, D.},
doi = {10.1038/nature14155},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7538},
pages = {219--222},
title = {{Boron isotope evidence for oceanic carbon dioxide leakage during the last deglaciation}},
url = {http://www.nature.com/articles/nature14155 https://www.nature.com/articles/nature14155},
volume = {518},
year = {2015}
}
@article{Martinez-Garcia2014,
abstract = {John H. Martin, who discovered widespread iron limitation of ocean productivity, proposed that dust-borne iron fertilization of Southern Ocean phytoplankton caused the ice age reduction in atmospheric carbon dioxide (CO2). In a sediment core from the Subantarctic Atlantic, we measured foraminifera-bound nitrogen isotopes to reconstruct ice age nitrate consumption, burial fluxes of iron, and proxies for productivity. Peak glacial times and millennial cold events are characterized by increases in dust flux, productivity, and the degree of nitrate consumption; this combination is uniquely consistent with Subantarctic iron fertilization. The associated strengthening of the Southern Ocean's biological pump can explain the lowering of CO2 at the transition from mid-climate states to full ice age conditions as well as the millennial-scale CO2 oscillations.},
annote = {10.1126/science.1246848},
author = {Mart{\'{i}}nez-Garc{\'{i}}a, A. and Sigman, Daniel M and Ren, Haojia and Anderson, Robert F and Straub, Marietta and Hodell, David A and Jaccard, Samuel L and Eglinton, Timothy I and Haug, Gerald H},
doi = {10.1126/science.1246848},
issn = {0036-8075},
journal = {Science},
month = {mar},
number = {6177},
pages = {1347--1350},
title = {{Iron Fertilization of the Subantarctic Ocean During the Last Ice Age}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1246848},
volume = {343},
year = {2014}
}
@article{Martinez-Rey2015,
abstract = {Abstract. The ocean is a substantial source of nitrous oxide (N2O) to the atmosphere, but little is known about how this flux might change in the future. Here, we investigate the potential evolution of marine N2O emissions in the 21st century in response to anthropogenic climate change using the global ocean biogeochemical model NEMO-PISCES. Assuming nitrification as the dominant N2O formation pathway, we implemented two different parameterizations of N2O production which differ primarily under low-oxygen (O2) conditions. When forced with output from a climate model simulation run under the business-as-usual high-CO2 concentration scenario (RCP8.5), our simulations suggest a decrease of 4 to 12 {\%} in N2O emissions from 2005 to 2100, i.e., a reduction from 4.03/3.71 to 3.54/3.56 TgN yr−1 depending on the parameterization. The emissions decrease strongly in the western basins of the Pacific and Atlantic oceans, while they tend to increase above the oxygen minimum zones (OMZs), i.e., in the eastern tropical Pacific and in the northern Indian Ocean. The reduction in N2O emissions is caused on the one hand by weakened nitrification as a consequence of reduced primary and export production, and on the other hand by stronger vertical stratification, which reduces the transport of N2O from the ocean interior to the ocean surface. The higher emissions over the OMZ are linked to an expansion of these zones under global warming, which leads to increased N2O production, associated primarily with denitrification. While there are many uncertainties in the relative contribution and changes in the N2O production pathways, the increasing storage seems unequivocal and determines largely the decrease in N2O emissions in the future. From the perspective of a global climate system, the averaged feedback strength associated with the projected decrease in oceanic N2O emissions amounts to around −0.009 W m−2 K−1, which is comparable to the potential increase from terrestrial N2O sources. However, the assessment for a potential balance between the terrestrial and marine feedbacks calls for an improved representation of N2O production terms in fully coupled next-generation Earth system models.},
author = {Martinez-Rey, J. and Bopp, L. and Gehlen, M. and Tagliabue, A. and Gruber, N.},
doi = {10.5194/bg-12-4133-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jul},
number = {13},
pages = {4133--4148},
title = {{Projections of oceanic N2O emissions in the 21st century using the IPSL Earth system model}},
url = {https://www.biogeosciences.net/12/4133/2015/},
volume = {12},
year = {2015}
}
@article{Mastrotheodoros2017,
author = {Mastrotheodoros, Theodoros and Pappas, Christoforos and Molnar, Peter and Burlando, Paolo and Keenan, Trevor F. and Gentine, Pierre and Gough, Christopher M. and Fatichi, Simone},
doi = {10.1002/2017JG003890},
issn = {21698953},
journal = {Journal of Geophysical Research: Biogeosciences},
month = {sep},
number = {9},
pages = {2393--2408},
title = {{Linking plant functional trait plasticity and the large increase in forest water use efficiency}},
url = {http://doi.wiley.com/10.1002/2017JG003890},
volume = {122},
year = {2017}
}
@article{Matear2014a,
abstract = {Abstract. Ocean acidification (OA) is the consequence of rising atmospheric CO2 levels, and it is occurring in conjunction with global warming. Observational studies show that OA will impact ocean biogeochemical cycles. Here, we use an Earth system model under the RCP8.5 emission scenario to evaluate and quantify the first-order impacts of OA on marine biogeochemical cycles, and its potential feedback on our future climate. We find that OA impacts have only a small impact on the future atmospheric CO2 (less than 45 ppm) and global warming (less than a 0.25 K) by 2100. While the climate change feedbacks are small, OA impacts may significantly alter the distribution of biological production and remineralisation, which would alter the dissolved oxygen distribution in the ocean interior. Our results demonstrate that the consequences of OA will not be through its impact on climate change, but on how it impacts the flow of energy in marine ecosystems, which may significantly impact their productivity, composition and diversity.},
author = {Matear, R. J. and Lenton, A.},
doi = {10.5194/bg-11-3965-2014},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jul},
number = {14},
pages = {3965--3983},
title = {{Quantifying the impact of ocean acidification on our future climate}},
url = {https://www.biogeosciences.net/11/3965/2014/},
volume = {11},
year = {2014}
}
@article{Matear2018,
author = {Matear, Richard J. and Lenton, Andrew},
doi = {10.5194/bg-15-1721-2018},
isbn = {1726-4189},
issn = {1726-4189},
journal = {Biogeosciences},
month = {mar},
number = {6},
pages = {1721--1732},
title = {{Carbon–climate feedbacks accelerate ocean acidification}},
url = {https://www.biogeosciences.net/15/1721/2018/ https://bg.copernicus.org/articles/15/1721/2018/},
volume = {15},
year = {2018}
}
@article{Mathesius2015,
author = {Mathesius, Sabine and Hofmann, Matthias and Caldeira, Ken and Schellnhuber, Hans Joachim},
doi = {10.1038/nclimate2729},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {dec},
number = {12},
pages = {1107--1113},
title = {{Long-term response of oceans to CO2 removal from the atmosphere}},
url = {http://www.nature.com/articles/nclimate2729},
volume = {5},
year = {2015}
}
@article{Matthews2009,
abstract = {The global temperature response to increasing atmospheric CO2 is often quantified by metrics such as equilibrium climate sensitivity and transient climate response1. These approaches, however, do not account for carbon cycle feedbacks and therefore do not fully represent the net response of the Earth system to anthropogenic CO2 emissions. Climate–carbon modelling experiments have shown that: (1) the warming per unit CO2 emitted does not depend on the background CO2 concentration2; (2) the total allowable emissions for climate stabilization do not depend on the timing of those emissions3,4,5; and (3) the temperature response to a pulse of CO2 is approximately constant on timescales of decades to centuries3,6,7,8. Here we generalize these results and show that the carbon–climate response (CCR), defined as the ratio of temperature change to cumulative carbon emissions, is approximately independent of both the atmospheric CO2 concentration and its rate of change on these timescales. From observational constraints, we estimate CCR to be in the range 1.0–2.1 °C per trillion tonnes of carbon (Tt C) emitted (5th to 95th percentiles), consistent with twenty-first-century CCR values simulated by climate–carbon models. Uncertainty in land-use CO2 emissions and aerosol forcing, however, means that higher observationally constrained values cannot be excluded. The CCR, when evaluated from climate–carbon models under idealized conditions, represents a simple yet robust metric for comparing models, which aggregates both climate feedbacks and carbon cycle feedbacks. CCR is also likely to be a useful concept for climate change mitigation and policy; by combining the uncertainties associated with climate sensitivity, carbon sinks and climate–carbon feedbacks into a single quantity, the CCR allows CO2-induced global mean temperature change to be inferred directly from cumulative carbon emissions.},
author = {Matthews, H Damon and Gillett, Nathan P and Stott, Peter A and Zickfeld, Kirsten},
doi = {10.1038/nature08047},
issn = {0028-0836},
journal = {Nature},
month = {jun},
number = {7248},
pages = {829--832},
publisher = {Macmillan Publishers Limited. All rights reserved},
title = {{The proportionality of global warming to cumulative carbon emissions}},
url = {http://dx.doi.org/10.1038/nature08047 http://www.nature.com/articles/nature08047},
volume = {459},
year = {2009}
}
@article{Matthews2017,
author = {Matthews, H. Damon and Landry, Jean-S{\'{e}}bastien and Partanen, Antti-Ilari and Allen, Myles and Eby, Michael and Forster, Piers M. and Friedlingstein, Pierre and Zickfeld, Kirsten},
doi = {10.1007/s40641-017-0055-0},
issn = {2198-6061},
journal = {Current Climate Change Reports},
month = {mar},
number = {1},
pages = {69--77},
publisher = {Springer International Publishing},
title = {{Estimating carbon budgets for ambitious climate targets}},
url = {http://link.springer.com/10.1007/s40641-017-0055-0},
volume = {3},
year = {2017}
}
@article{Matthews2012a,
abstract = {The primary objective of the United Nations Framework Convention on Climate Change is to stabilize greenhouse gas concentrations at a level that will avoid dangerous climate impacts. However, greenhouse gas concentration stabilization is an awkward framework within which to assess dangerous climate change on account of the significant lag between a given concentration level and the eventual equilibrium temperature change. By contrast, recent research has shown that global temperature change can be well described by a given cumulative carbon emissions budget. Here, we propose that cumulative carbon emissions represent an alternative framework that is applicable both as a tool for climate mitigation as well as for the assessment of potential climate impacts. We show first that both atmospheric CO2 concentration at a given year and the associated temperature change are generally associated with a unique cumulative carbon emissions budget that is largely independent of the emissions scenario. The rate of glob...},
author = {Matthews, H. D. and Solomon, S. and Pierrehumbert, R.},
doi = {10.1098/rsta.2012.0064},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
keywords = {allowable emissions,carbon dioxide,climate change,climate stabilization,global warming,greenhouse gases},
month = {sep},
number = {1974},
pages = {4365--4379},
publisher = {The Royal Society Publishing},
title = {{Cumulative carbon as a policy framework for achieving climate stabilization}},
url = {http://rsta.royalsocietypublishing.org/cgi/doi/10.1098/rsta.2012.0064},
volume = {370},
year = {2012}
}
@article{Matthews2013,
author = {Matthews, H Damon and Solomon, Susan},
doi = {10.1126/science.1236372},
issn = {0036-8075},
journal = {Science},
month = {apr},
number = {6131},
pages = {438--439},
publisher = {American Association for the Advancement of Science},
title = {{Irreversible does not mean unavoidable}},
url = {http://science.sciencemag.org/content/340/6131/438 http://www.sciencemag.org/cgi/doi/10.1126/science.1236372},
volume = {340},
year = {2013}
}
@article{Matthews2007a,
abstract = {Geoengineering (the intentional modification of Earth's climate) has been proposed as a means of reducing CO2-induced climate warming while greenhouse gas emissions continue. Most proposals involve managing incoming solar radiation such that future greenhouse gas forcing is counteracted by reduced solar forcing. In this study, we assess the transient climate response to geoengineering under a business-as-usual CO2 emissions scenario by using an intermediate-complexity global climate model that includes an interactive carbon cycle. We find that the climate system responds quickly to artificially reduced insolation; hence, there may be little cost to delaying the deployment of geoengineering strategies until such a time as "dangerous" climate change is imminent. Spatial temperature patterns in the geoengineered simulation are comparable with preindustrial temperatures, although this is not true for precipitation. Carbon sinks in the model increase in response to geoengineering. Because geoengineering acts to mask climate warming, there is a direct CO2-driven increase in carbon uptake without an offsetting temperature-driven suppression of carbon sinks. However, this strengthening of carbon sinks, combined with the potential for rapid climate adjustment to changes in solar forcing, leads to serious consequences should geoengineering fail or be stopped abruptly. Such a scenario could lead to very rapid climate change, with warming rates up to 20 times greater than present-day rates. This warming rebound would be larger and more sustained should climate sensitivity prove to be higher than expected. Thus, employing geoengineering schemes with continued carbon emissions could lead to severe risks for the global climate system.},
author = {Matthews, H. D. and Caldeira, K.},
doi = {10.1073/pnas.0700419104},
isbn = {0027-8424},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {24},
pages = {9949--9954},
pmid = {17548822},
title = {{Transient climate carbon simulations of planetary geoengineering}},
volume = {104},
year = {2007}
}
@article{Matthews,
abstract = {The remaining carbon budget quantifies the future CO2 emissions to limit global warming below a desired level. Carbon budgets are subject to uncertainty in the Transient Climate Response to Cumulative CO2 Emissions (TCRE), as well as to non-CO2 climate influences. Here we estimate the TCRE using observational constraints, and integrate the geophysical and socioeconomic uncertainties affecting the distribution of the remaining carbon budget. We estimate a median TCRE of 0.44 °C and 5–95{\%} range of 0.32–0.62 °C per 1000 GtCO2 emitted. Considering only geophysical uncertainties, our median estimate of the 1.5 °C remaining carbon budget is 440 GtCO2 from 2020 onwards, with a range of 230–670 GtCO2, (for a 67–33{\%} chance of not exceeding the target). Additional socioeconomic uncertainty related to human decisions regarding future non-CO2 emissions scenarios can further shift the median 1.5 °C remaining carbon budget by ±170 GtCO2.},
author = {Matthews, H. Damon and Tokarska, Katarzyna B. and Rogelj, Joeri and Smith, Christopher J. and MacDougall, Andrew H. and Haustein, Karsten and Mengis, Nadine and Sippel, Sebastian and Forster, Piers M. and Knutti, Reto},
doi = {10.1038/s43247-020-00064-9},
journal = {Communications Earth {\&} Environment},
number = {1},
pages = {1--11},
title = {{An integrated approach to quantifying uncertainties in the remaining carbon budget}},
url = {https://doi.org/10.1038/s43247-020-00064-9},
volume = {2},
year = {2021}
}
@article{Matthews2020,
author = {Matthews, H Damon and Tokarska, Katarzyna B and Nicholls, Zebedee R J and Rogelj, Joeri and Canadell, Josep G and Friedlingstein, Pierre and Forster, Piers M and Gillett, Nathan P and Ilyina, Tatiana and Jackson, Robert B and Jones, Chris D and Koven, Charles and Knutti, Reto and Macdougall, Andrew H and Meinshausen, Malte and Mengis, Nadine and Zickfeld, Kirsten},
doi = {10.1038/s41561-020-00663-3},
isbn = {4156102000663},
journal = {Nature Geoscience},
number = {12},
pages = {769--779},
title = {{Opportunities and challenges in using remaining carbon budgets to guide climate policy}},
volume = {13},
year = {2020}
}
@article{MattsdotterBjork2014a,
author = {{Mattsdotter Bj{\"{o}}rk}, M and Fransson, A and Torstensson, A and Chierici, M},
doi = {10.5194/bg-11-57-2014},
journal = {Biogeosciences},
number = {1},
pages = {57--73},
title = {{Ocean acidification state in western Antarctic surface waters: controls and interannual variability}},
url = {https://bg.copernicus.org/articles/11/57/2014/},
volume = {11},
year = {2014}
}
@article{Maxwell2019,
abstract = {Intact tropical forests, free from substantial anthropogenic influence, store and sequester large amounts of atmospheric carbon but are currently neglected in international climate policy. We show that between 2000 and 2013, direct clearance of intact tropical forest areas accounted for 3.2{\%} of gross carbon emissions from all deforestation across the pantropics. However, full carbon accounting requires the consideration of forgone carbon sequestration, selective logging, edge effects, and defaunation. When these factors were considered, the net carbon impact resulting from intact tropical forest loss between 2000 and 2013 increased by a factor of 6 (626{\%}), from 0.34 (0.37 to 0.21) to 2.12 (2.85 to 1.00) petagrams of carbon (equivalent to approximately 2 years of global land use change emissions). The climate mitigation value of conserving the 549 million ha of tropical forest that remains intact is therefore significant but will soon dwindle if their rate of loss continues to accelerate.},
author = {Maxwell, Sean L and Evans, Tom and Watson, James E M and Morel, Alexandra and Grantham, Hedley and Duncan, Adam and Harris, Nancy and Potapov, Peter and Runting, Rebecca K and Venter, Oscar and Wang, Stephanie and Malhi, Yadvinder},
doi = {10.1126/sciadv.aax2546},
journal = {Science Advances},
month = {oct},
number = {10},
pages = {eaax2546},
title = {{Degradation and forgone removals increase the carbon impact of intact forest loss by 626{\%}}},
url = {http://advances.sciencemag.org/content/5/10/eaax2546.abstract},
volume = {5},
year = {2019}
}
@article{McCormack2016,
annote = {doi: 10.1080/1943815X.2016.1159578},
author = {McCormack, Caitlin G and Born, Wanda and Irvine, Peter J and Achterberg, Eric P and Amano, Tatsuya and Ardron, Jeff and Foster, Pru N and Gattuso, Jean-Pierre and Hawkins, Stephen J and Hendy, Erica and Kissling, W Daniel and Lluch-Cota, Salvador E and Murphy, Eugene J and Ostle, Nick and Owens, Nicholas J.P. and Perry, R Ian and P{\"{o}}rtner, Hans O and Scholes, Robert J and Schurr, Frank M and Schweiger, Oliver and Settele, Josef and Smith, Rebecca K. and Smith, Sarah and Thompson, Jill and Tittensor, Derek P and van Kleunen, Mark and Vivian, Chris and Vohland, Katrin and Warren, Rachel and Watkinson, Andrew R and Widdicombe, Steve and Williamson, Phillip and Woods, Emma and Blackstock, Jason J and Sutherland, William J},
doi = {10.1080/1943815X.2016.1159578},
issn = {1943-815X},
journal = {Journal of Integrative Environmental Sciences},
month = {mar},
number = {2-4},
pages = {1--26},
publisher = {Taylor {\&} Francis},
title = {{Key impacts of climate engineering on biodiversity and ecosystems, with priorities for future research}},
url = {https://doi.org/10.1080/1943815X.2016.1159578 http://www.tandfonline.com/doi/full/10.1080/1943815X.2016.1159578},
volume = {13},
year = {2016}
}
@article{McCusker2014,
abstract = {Solar radiation management (SRM) has been proposed as a means to alleviate the climate impacts of ongoing anthropogenic greenhouse gas (GHG) emissions. However, its efficacy depends on its indefinite maintenance, without interruption from a variety of possible sources, such as technological failure or global cooperation breakdown. Here, we consider the scenario in which SRM—via stratospheric aerosol injection—is terminated abruptly following an implementation period during which anthropogenic GHG emissions have continued. We show that upon cessation of SRM, an abrupt, spatially broad, and sustained warming over land occurs that is well outside 20th century climate variability bounds. Global mean precipitation also increases rapidly following cessation, however spatial patterns are less coherent than temperature, with almost half of land areas experiencing drying trends. We further show that the rate of warming—of critical importance for ecological and human systems—is principally controlled by background GHG levels. Thus, a risk of abrupt and dangerous warming is inherent to the large-scale implementation of SRM, and can be diminished only through concurrent strong reductions in anthropogenic GHG emissions.},
author = {McCusker, Kelly E. and Armour, Kyle C. and Bitz, Cecilia M. and Battisti, David S.},
doi = {10.1088/1748-9326/9/2/024005},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jan},
number = {2},
pages = {024005},
title = {{Rapid and extensive warming following cessation of solar radiation management}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/9/2/024005},
volume = {9},
year = {2014}
}
@article{McDaniel2019,
abstract = {Land-use change is a prominent feature of the Anthropocene. Transitions between natural and human-managed ecosystems affect biogeochemical cycles in many ways, but soil processes are among the least understood. We used a global meta-analysis (62 studies, 1670 paired comparisons) to examine effects of land conversion on soil–atmosphere fluxes of methane (CH4) and nitrous oxide (N2O) from upland soils, and determine soil and environmental factors driving these effects. Conversion from a natural ecosystem to any anthropogenic land use increased soil CH4 and N2O fluxes by 234 kg CO2-equivalents ha−1 y−1, on average. Reversion of managed ecosystems to that resembling natural ecosystems did not fully reverse those effects, even after 80 years. In general, neither the type of ecosystem converted, nor the type of subsequent anthropogenic land use, affected the magnitude of increase in soil emissions. Land-use changes in wetter ecosystems resulted in greater increases in CH4 fluxes, but reduced N2O fluxes. An interacting suite of soil variables influenced CH4 and N2O fluxes, with availability of inorganic nitrogen (that is, extractable ammonium and nitrate), pH, total carbon, and microclimate being strong mediators of effects of land-use change. In addition, time after a change in land use emerged as a critical factor explaining the effects of land-use change—with increased emissions of both greenhouse gases diminishing rapidly after conversion. Further research is needed to elucidate complex biotic and abiotic mechanisms that drive land-use change effects on soil greenhouse gas emissions, but particularly during this initial disturbance when emissions are greatest relative to native vegetation. Efforts to mitigate emissions will be severely hampered by this gap in knowledge.},
author = {McDaniel, M D and Saha, D and Dumont, M G and Hern{\'{a}}ndez, M and Adams, M A},
doi = {10.1007/s10021-019-00347-z},
issn = {1435-0629},
journal = {Ecosystems},
number = {6},
pages = {1424--1443},
title = {{The effect of land-use change on soil CH4 and N2O fluxes: a global meta-analysis}},
volume = {22},
year = {2019}
}
@article{McDermid2021,
abstract = {Key Points: • We evaluate the separate and combined biophysical vegetation effects on hydroclimate in a high-CO2 world using the GISS ModelE global climate model • Increased leaf areas enhance soil moisture drying at lower latitudes; reduced stomatal conductance enhances high-latitude warming • Increased leaf area and reduced stomatal conductance also produce complex nonlinear and either competing or mutually amplifying regional hydroclimate responses Abstract: Biophysical vegetation responses to elevated atmospheric carbon dioxide (CO2) affect regional hydroclimate through two competing mechanisms. Higher CO2 increases leaf area (LAI), thereby increasing transpiration and water losses. Simultaneously, elevated CO2 reduces stomatal conductance and transpiration, thereby increasing rootzone soil moisture. Which mechanism dominates in the future is highly uncertain, partly because these two processes are difficult to explicitly separate within dynamic vegetation models. We address this challenge by using the GISS ModelE global climate model to conduct a novel set of idealized 2xCO2 sensitivity experiments to: evaluate the total vegetation biophysical contribution to regional climate change under high CO2; and quantify the separate contributions of enhanced LAI and reduced stomatal conductance to regional hydroclimate responses. We find that increased LAI exacerbates soil moisture deficits across the sub-tropics and more water-limited regions, but also attenuates warming by {\~{}}0.5-1˚C in the US Southwest, Central Asia, Southeast Asia, and northern South America. Reduced stomatal conductance effects contribute {\~{}}1˚C of summertime warming. For some regions, enhanced LAI and reduced stomatal conductance produce nonlinear and either competing or mutually-amplifying hydroclimate responses. In northeastern Australia, these effects combine to exacerbate radiation-forced warming and contribute to year-round water limitation. Conversely, at higher latitudes these combined effects result in less warming than would otherwise be predicted due to nonlinear responses. These results highlight substantial regional variation in CO2-driven vegetation responses and the importance of improving model representations of these processes to better quantify regional hydroclimate impacts.},
author = {McDermid, Sonali Shukla and Cook, Benjamin I. and {De Kauwe}, Martin G. and Mankin, Justin and Smerdon, Jason E. and Williams, A. Park and Seager, Richard and Puma, Michael J. and Aleinov, Igor and Kelley, Maxwell and Nazarenko, Larissa},
doi = {10.1029/2020JD034108},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {mar},
number = {5},
pages = {e2020JD034108},
title = {{Disentangling the Regional Climate Impacts of Competing Vegetation Responses to Elevated Atmospheric CO2}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2020JD034108},
volume = {126},
year = {2021}
}
@article{doi:10.1111/nph.15027,
abstract = {Summary Tree mortality rates appear to be increasing in moist tropical forests (MTFs) with significant carbon cycle consequences. Here, we review the state of knowledge regarding MTF tree mortality, create a conceptual framework with testable hypotheses regarding the drivers, mechanisms and interactions that may underlie increasing MTF mortality rates, and identify the next steps for improved understanding and reduced prediction. Increasing mortality rates are associated with rising temperature and vapor pressure deficit, liana abundance, drought, wind events, fire and, possibly, CO2 fertilization-induced increases in stand thinning or acceleration of trees reaching larger, more vulnerable heights. The majority of these mortality drivers may kill trees in part through carbon starvation and hydraulic failure. The relative importance of each driver is unknown. High species diversity may buffer MTFs against large-scale mortality events, but recent and expected trends in mortality drivers give reason for concern regarding increasing mortality within MTFs. Models of tropical tree mortality are advancing the representation of hydraulics, carbon and demography, but require more empirical knowledge regarding the most common drivers and their subsequent mechanisms. We outline critical datasets and model developments required to test hypotheses regarding the underlying causes of increasing MTF mortality rates, and improve prediction of future mortality under climate change.},
author = {McDowell, Nate and Allen, Craig D and Anderson-Teixeira, Kristina and Brando, Paulo and Brienen, Roel and Chambers, Jeff and Christoffersen, Brad and Davies, Stuart and Doughty, Chris and Duque, Alvaro and Espirito-Santo, Fernando and Fisher, Rosie and Fontes, Clarissa G and Galbraith, David and Goodsman, Devin and Grossiord, Charlotte and Hartmann, Henrik and Holm, Jennifer and Johnson, Daniel J and Kassim, Abd. Rahman and Keller, Michael and Koven, Charlie and Kueppers, Lara and Kumagai, Tomo'omi and Malhi, Yadvinder and McMahon, Sean M and Mencuccini, Maurizio and Meir, Patrick and Moorcroft, Paul and Muller-Landau, Helene C and Phillips, Oliver L and Powell, Thomas and Sierra, Carlos A and Sperry, John and Warren, Jeff and Xu, Chonggang and Xu, Xiangtao},
doi = {10.1111/nph.15027},
journal = {New Phytologist},
keywords = {CO2 fertilization,carbon (C) starvation,forest mortality,hydraulic failure,tropical forests},
number = {3},
pages = {851--869},
title = {{Drivers and mechanisms of tree mortality in moist tropical forests}},
url = {https://nph.onlinelibrary.wiley.com/doi/abs/10.1111/nph.15027},
volume = {219},
year = {2018}
}
@article{McDowell2015,
abstract = {Forest dynamics are the processes of recruitment, growth, death, and turnover of the constituent tree species of the forest community. These processes are driven by disturbances both natural and anthropogenic. McDowell et al. review recent progress in understanding the drivers of forest dynamics and how these are interacting and changing in the context of global climate change. The authors show that shifts in forest dynamics are already occurring, and the emerging pattern is that global forests are tending toward younger stands with faster turnover as old-growth forest with stable dynamics are dwindling.},
author = {McDowell, Nate G. and Allen, Craig D. and Anderson-Teixeira, Kristina and Aukema, Brian H. and Bond-Lamberty, Ben and Chini, Louise and Clark, James S. and Dietze, Michael and Grossiord, Charlotte and Hanbury-Brown, Adam and Hurtt, George C. and Jackson, Robert B. and Johnson, Daniel J. and Kueppers, Lara and Lichstein, Jeremy W. and Ogle, Kiona and Poulter, Benjamin and Pugh, Thomas A. M. and Seidl, Rupert and Turner, Monica G. and Uriarte, Maria and Walker, Anthony P. and Xu, Chonggang},
doi = {10.1126/science.aaz9463},
issn = {0036-8075},
journal = {Science},
keywords = {CESM,CO2,CO2 enrichment,CO2 fertilization,Carbon starvation,Climate change,Drought,ESA centennial paper,Extreme events,Forest die-off,Forest hydrology,Forests,Global change,Hydraulic failure,Insect pests,Pathogens,Sap flow,Soil moisture,Thermal imagery,Tree mortality,VPD response,Web-FACE,Woodlands,drought,ecosystems,fluxes,hydrology,mortality,productivity,runoff,soil moisture,stomatal conductance,transpiration,vapor pressure deficit,vegetation,warming,water cycle,water use efficiency},
month = {may},
number = {6494},
pages = {eaaz9463},
publisher = {Springer US},
title = {{Pervasive shifts in forest dynamics in a changing world}},
url = {https://www.science.org/doi/10.1126/science.aaz9463},
volume = {368},
year = {2020}
}
@article{McGuire2018,
abstract = {We conducted a model-based assessment of changes in permafrost area and carbon storage for simulations driven by RCP4.5 and RCP8.5 projections between 2010 and 2299 for the northern permafrost region. All models simulating carbon represented soil with depth, a critical structural feature needed to represent the permafrost carbon–climate feedback, but that is not a universal feature of all climate models. Between 2010 and 2299, simulations indicated losses of permafrost between 3 and 5 million km 2 for the RCP4.5 climate and between 6 and 16 million km 2 for the RCP8.5 climate. For the RCP4.5 projection, cumulative change in soil carbon varied between 66-Pg C (10 15 -g carbon) loss to 70-Pg C gain. For the RCP8.5 projection, losses in soil carbon varied between 74 and 652 Pg C (mean loss, 341 Pg C). For the RCP4.5 projection, gains in vegetation carbon were largely responsible for the overall projected net gains in ecosystem carbon by 2299 (8- to 244-Pg C gains). In contrast, for the RCP8.5 projection, gains in vegetation carbon were not great enough to compensate for the losses of carbon projected by four of the five models; changes in ecosystem carbon ranged from a 641-Pg C loss to a 167-Pg C gain (mean, 208-Pg C loss). The models indicate that substantial net losses of ecosystem carbon would not occur until after 2100. This assessment suggests that effective mitigation efforts during the remainder of this century could attenuate the negative consequences of the permafrost carbon–climate feedback.},
author = {McGuire, A David and Lawrence, David M and Koven, Charles and Clein, Joy S and Burke, Eleanor and Chen, Guangsheng and Jafarov, Elchin and MacDougall, Andrew H and Marchenko, Sergey and Nicolsky, Dmitry and Peng, Shushi and Rinke, Annette and Ciais, Philippe and Gouttevin, Isabelle and Hayes, Daniel J and Ji, Duoying and Krinner, Gerhard and Moore, John C and Romanovsky, Vladimir and Sch{\"{a}}del, Christina and Schaefer, Kevin and Schuur, Edward A G and Zhuang, Qianlai},
doi = {10.1073/pnas.1719903115},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {apr},
number = {15},
pages = {3882--3887},
title = {{Dependence of the evolution of carbon dynamics in the northern permafrost region on the trajectory of climate change}},
url = {http://www.pnas.org/content/115/15/3882.abstract http://www.pnas.org/lookup/doi/10.1073/pnas.1719903115},
volume = {115},
year = {2018}
}
@article{McInerney2011,
abstract = {During the Paleocene-Eocene Thermal Maximum (PETM), ∼56 Mya, thousands of petagrams of carbon were released into the ocean-atmosphere system with attendant changes in the carbon cycle, climate, ocean chemistry, and marine and continental ecosystems. The period of carbon release is thought to have lasted {\textless}20 ka, the duration of the whole event was ∼200 ka, and the global temperature increase was 5–8°C. Terrestrial and marine organisms experienced large shifts in geographic ranges, rapid evolution, and changes in trophic ecology, but few groups suffered major extinctions with the exception of benthic foraminifera. The PETM provides valuable insights into the carbon cycle, climate system, and biotic responses to environmental change that are relevant to long-term future global changes.},
author = {McInerney, Francesca A. and Wing, Scott L.},
doi = {10.1146/annurev-earth-040610-133431},
issn = {0084-6597},
journal = {Annual Review of Earth and Planetary Sciences},
keywords = {PETM,carbon cycle,global warming,paleoclimate,paleoecology},
month = {may},
number = {1},
pages = {489--516},
publisher = {Annual Reviews},
title = {{The Paleocene-Eocene Thermal Maximum: A Perturbation of Carbon Cycle, Climate, and Biosphere with Implications for the Future}},
url = {http://www.annualreviews.org/doi/10.1146/annurev-earth-040610-133431},
volume = {39},
year = {2011}
}
@article{McKinley2016,
abstract = {A climate modelling experiment is used to identify where ocean carbon uptake should change as a result of anthropogenic climate change and to distinguish these changes from internal climate variability; we may be able to detect changing uptake in some oceanic regions between 2020 and 2050, but until then, internal climate variability will preclude such detection.},
author = {McKinley, Galen A. and Pilcher, Darren J. and Fay, Amanda R. and Lindsay, Keith and Long, Matthew C. and Lovenduski, Nicole S.},
doi = {10.1038/nature16958},
issn = {0028-0836},
journal = {Nature},
keywords = {Biogeochemistry,Marine chemistry},
month = {feb},
number = {7591},
pages = {469--472},
publisher = {Nature Publishing Group},
title = {{Timescales for detection of trends in the ocean carbon sink}},
url = {http://www.nature.com/articles/nature16958},
volume = {530},
year = {2016}
}
@article{McKinley2017,
abstract = {{\textcopyright}2017 by Annual Reviews. All rights reserved. Since preindustrial times, the ocean has removed from the atmosphere 41{\%} of the carbon emitted by human industrial activities. Despite significant uncertainties, the balance of evidence indicates that the globally integrated rate of ocean carbon uptake is increasing in response to increasing atmospheric CO2 concentrations. The El Ni{\~{n}}o-Southern Oscillation in the equatorial Pacific dominates interannual variability of the globally integrated sink. Modes of climate variability in high latitudes are correlated with variability in regional carbon sinks, but mechanistic understanding is incomplete. Regional sink variability, combined with sparse sampling, means that the growing oceanic sink cannot yet be directly detected from available surface data. Accurate and precise shipboard observations need to be continued and increasingly complemented with autonomous observations. These data, together with a variety of mechanistic and diagnostic models, are needed for better understanding, long-term monitoring, and future projections of this critical climate regulation service.},
author = {McKinley, Galen A. and Fay, Amanda R. and Lovenduski, Nicole S. and Pilcher, Darren J.},
doi = {10.1146/annurev-marine-010816-060529},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {125--150},
title = {{Natural Variability and Anthropogenic Trends in the Ocean Carbon Sink}},
url = {http://www.annualreviews.org/doi/10.1146/annurev-marine-010816-060529},
volume = {9},
year = {2017}
}
@article{McKinley,
abstract = {The ocean has absorbed the equivalent of 39{\%} of industrial‐age fossil carbon emissions, significantly modulating the growth rate of atmospheric CO2 and its associated impacts on climate. Despite the importance of the ocean carbon sink to climate, our understanding of the causes of its interannual‐to‐decadal variability remains limited. This hinders our ability to attribute its past behavior and project its future. A key period of interest is the 1990s, when the ocean carbon sink did not grow as expected. Previous explanations of this behavior have focused on variability internal to the ocean or associated with coupled atmosphere/ocean modes. Here, we use an idealized upper ocean box model to illustrate that two external forcings are sufficient to explain the pattern and magnitude of sink variability since the mid‐1980s. First, the global‐scale reduction in the decadal‐average ocean carbon sink in the 1990s is attributable to the slowed growth rate of atmospheric pCO2. The acceleration of atmospheric pCO2 growth after 2001 drove recovery of the sink. Second, the global sea surface temperature response to the 1991 eruption of Mt Pinatubo explains the timing of the global sink within the 1990s. These results are consistent with previous experiments using ocean hindcast models with variable atmospheric pCO2 and with and without climate variability. The fact that variability in the growth rate of atmospheric pCO2 directly imprints on the ocean sink implies that there will be an immediate reduction in ocean carbon uptake as atmospheric pCO2 responds to cuts in anthropogenic emissions.},
author = {McKinley, Galen A. and Fay, Amanda R. and Eddebbar, Yassir A. and Gloege, Lucas and Lovenduski, Nicole S.},
doi = {10.1029/2019AV000149},
issn = {2576-604X},
journal = {AGU Advances},
keywords = {carbon cycle,forced,internal,ocean carbon sink},
month = {jun},
number = {2},
pages = {e2019AV000149},
publisher = {American Geophysical Union (AGU)},
title = {{External Forcing Explains Recent Decadal Variability of the Ocean Carbon Sink}},
volume = {1},
year = {2020}
}
@article{Mcleod2011,
abstract = {Recent research has highlighted the valuable role that coastal and marine ecosystems play in sequestering carbon dioxide (CO2). The carbon (C) sequestered in vegetated coastal ecosystems, specifically mangrove forests, seagrass beds, and salt marshes, has been termed ?blue carbon?. Although their global area is one to two orders of magnitude smaller than that of terrestrial forests, the contribution of vegetated coastal habitats per unit area to long-term C sequestration is much greater, in part because of their efficiency in trapping suspended matter and associated organic C during tidal inundation. Despite the value of mangrove forests, seagrass beds, and salt marshes in sequestering C, and the other goods and services they provide, these systems are being lost at critical rates and action is urgently needed to prevent further degradation and loss. Recognition of the C sequestration value of vegetated coastal ecosystems provides a strong argument for their protection and restoration; however, it is necessary to improve scientific understanding of the underlying mechanisms that control C sequestration in these ecosystems. Here, we identify key areas of uncertainty and specific actions needed to address them.},
annote = {doi: 10.1890/110004},
author = {Mcleod, Elizabeth and Chmura, Gail L and Bouillon, Steven and Salm, Rodney and Bj{\"{o}}rk, Mats and Duarte, Carlos M and Lovelock, Catherine E and Schlesinger, William H and Silliman, Brian R},
doi = {10.1890/110004},
issn = {1540-9295},
journal = {Frontiers in Ecology and the Environment},
month = {dec},
number = {10},
pages = {552--560},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{A blueprint for blue carbon: toward an improved understanding of the role of vegetated coastal habitats in sequestering CO2}},
url = {https://doi.org/10.1890/110004 http://doi.wiley.com/10.1890/110004},
volume = {9},
year = {2011}
}
@article{McManus2004,
abstract = {The Atlantic meridional overturning circulation is widely believed to affect climate. Changes in ocean circulation have been inferred from records of the deep water chemical composition derived from sedimentary nutrient proxies, but their impact on climate is difficult to assess because such reconstructions provide insufficient constraints on the rate of overturning. Here we report measurements of 231Pa/230Th, a kinematic proxy for the meridional overturning circulation, in a sediment core from the subtropical North Atlantic Ocean. We find that the meridional overturning was nearly, or completely, eliminated during the coldest deglacial interval in the North Atlantic region, beginning with the catastrophic iceberg discharge Heinrich event H1, 17,500 yr ago, and declined sharply but briefly into the Younger Dryas cold event, about 12,700 yr ago. Following these cold events, the 231Pa/230Th record indicates that rapid accelerations of the meridional overturning circulation were concurrent with the two strongest regional warming events during deglaciation. These results confirm the significance of variations in the rate of the Atlantic meridional overturning circulation for abrupt climate changes.},
author = {McManus, J. F. and Francois, R. and Gherardi, J.-M. and Keigwin, L. D. and Brown-Leger, S.},
doi = {10.1038/nature02494},
isbn = {1476-4687 (Electronic)$\backslash$r0028-0836 (Linking)},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {6985},
pages = {834--837},
pmid = {15103371},
title = {{Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes}},
url = {http://www.nature.com/articles/nature02494},
volume = {428},
year = {2004}
}
@article{McNeil2016,
abstract = {Data-based projections suggest that the natural CO2 cycle could be amplified by up to ten times by 2100 in some oceanic regions if atmospheric CO2 concentrations continue to increase, which could detrimentally affect major fisheries.},
author = {McNeil, Ben I. and Sasse, Tristan P.},
doi = {10.1038/nature16156},
issn = {0028-0836},
journal = {Nature},
keywords = {Biogeochemistry,Marine chemistry},
month = {jan},
number = {7586},
pages = {383--386},
publisher = {Nature Publishing Group},
title = {{Future ocean hypercapnia driven by anthropogenic amplification of the natural CO2 cycle}},
url = {http://www.nature.com/articles/nature16156},
volume = {529},
year = {2016}
}
@article{McNorton2018,
author = {McNorton, Joe and Wilson, Chris and Gloor, Manuel and Parker, Rob J and Boesch, Hartmut and Feng, Wuhu and Hossaini, Ryan and Chipperfield, Martyn P},
doi = {10.5194/acp-18-18149-2018},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {dec},
number = {24},
pages = {18149--18168},
publisher = {Copernicus Publications},
title = {{Attribution of recent increases in atmospheric methane through 3-D inverse modelling}},
url = {https://acp.copernicus.org/articles/18/18149/2018/},
volume = {18},
year = {2018}
}
@article{Medlyn2015,
abstract = {Ecosystem responses to rising CO2 concentrations are a major source of uncertainty in climate change projections. Data from ecosystem-scale Free-Air CO2 Enrichment (FACE) experiments provide a unique opportunity to reduce this uncertainty. The recent FACE Model-Data Synthesis project aimed to use the information gathered in two forest FACE experiments to assess and improve land ecosystem models. A new 'assumption-centred' model intercomparison approach was used, in which participating models were evaluated against experimental data based on the ways in which they represent key ecological processes. By identifying and evaluating the main assumptions causing differences among models, the assumption-centred approach produced a clear roadmap for reducing model uncertainty. Here, we explain this approach and summarize the resulting research agenda. We encourage the application of this approach in other model intercomparison projects to fundamentally improve predictive understanding of the Earth system.},
author = {Medlyn, Belinda E. and Zaehle, S{\"{o}}nke and {De Kauwe}, Martin G. and Walker, Anthony P. and Dietze, Michael C. and Hanson, Paul J. and Hickler, Thomas and Jain, Atul K. and Luo, Yiqi and Parton, William and Prentice, I. Colin and Thornton, Peter E. and Wang, Shusen and Wang, Ying-Ping and Weng, Ensheng and Iversen, Colleen M. and McCarthy, Heather R. and Warren, Jeffrey M. and Oren, Ram and Norby, Richard J.},
doi = {10.1038/nclimate2621},
isbn = {1758-678X},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jun},
number = {6},
pages = {528--534},
publisher = {Nature Publishing Group},
title = {{Using ecosystem experiments to improve vegetation models}},
url = {http://dx.doi.org/10.1038/nclimate2621 http://www.nature.com/articles/nclimate2621},
volume = {5},
year = {2015}
}
@article{Medlyn2016,
abstract = {The response of terrestrial ecosystems to rising atmospheric CO2 concentration (Ca ), particularly under nutrient limited conditions, is a major uncertainty in Earth System models. The Eucalyptus Free-Air CO2 Enrichment (EucFACE) experiment, recently established in a nutrient-and water-limited woodland, presents a unique opportunity to address this uncertainty, but can best do so if key model uncertainties have been identified in advance. We applied seven vegetation models, which have previously been comprehensively assessed against earlier forest FACE experiments, to simulate a priori possible outcomes from EucFACE. Our goals were to provide quantitative projections against which to evaluate data as they are collected, and to identify key measurements that should be made in the experiment to allow discrimination among alternative model assumptions in a post-experiment model intercomparison. Simulated responses of annual net primary productivity (NPP) to elevated Ca ranged from 0.5 to 25{\%} across models. The simulated reduction of NPP during a low rainfall year also varied widely, from 24{\%} to 70{\%}. Key processes where assumptions caused disagreement among models included nutrient limitations to growth; feedbacks to nutrient uptake; autotrophic respiration; and the impact of low soil moisture availability on plant processes. Knowledge of the causes of variation among models is now guiding data collection in the experiment, with the expectation that the experimental data can optimally inform future model improvements. This article is protected by copyright. All rights reserved.},
author = {Medlyn, Belinda E. and {De Kauwe}, Martin G. and Zaehle, S{\"{o}}nke and Walker, Anthony P. and Duursma, Remko A. and Luus, Kristina and Mishurov, Mikhail and Pak, Bernard and Smith, Benjamin and Wang, Ying-Ping and Yang, Xiaojuan and Crous, Kristine Y. and Drake, John E. and Gimeno, Teresa E. and Macdonald, Catriona A. and Norby, Richard J. and Power, Sally A. and Tjoelker, Mark G. and Ellsworth, David S.},
doi = {10.1111/gcb.13268},
isbn = {7034894671},
issn = {13541013},
journal = {Global Change Biology},
keywords = {Eucalyptus tereticornis,carbon dioxide,drought,ecosystem model,phosphorus},
month = {aug},
number = {8},
pages = {2834--2851},
pmid = {26946185},
title = {{Using models to guide field experiments: a priori predictions for the CO2 response of a nutrient- and water-limited native Eucalypt woodland}},
url = {http://doi.wiley.com/10.1111/gcb.13268},
volume = {22},
year = {2016}
}
@article{Meier2017,
abstract = {Theory and experiments suggest that rhizodeposition can accelerate N-cycling by stimulating microbial decomposition of soil organic matter (SOM). However, there are remarkably few experimental demonstrations on the degree to which variations in root exudation alter rhizosphere N dynamics in the field. We conducted a series of in situ substrate addition experiments and a modeling exercise to investigate how exudate mimics and enzyme solutions (at varying concentrations) influence rhizosphere SOM and N dynamics in a loblolly pine (Pinus taeda) plantation (Duke Forest). Exudates were added semi-continuously to unfertilized and fertilized soils in summer and fall; enzymes were added during the following summer. Exudate additions enhanced the microbial biomass specific activities of enzymes that degrade fast-cycling N pools (i.e., amino acids and amino sugars), and increased microbial allocation to N-degrading compounds. More, such effects occurred at low exudate concentrations in unfertilized soil and at higher concentrations in fertilized soil. Direct additions of a subset of enzymes (amino sugar- and cellulose-degrading) to soils increased net N mineralization rates, but additions of enzymes that cleave slow-cycling SOM did not. We conclude that exudates can stimulate microbes to decompose labile SOM and release N without concomitant changes in microbial biomass, yet the investment of plants to trigger this effect may be greater in N-rich soils.},
author = {Meier, Ina C. and Finzi, Adrien C. and Phillips, Richard P.},
doi = {10.1016/j.soilbio.2016.12.004},
isbn = {1847491863},
issn = {00380717},
journal = {Soil Biology and Biochemistry},
keywords = {Extracellular enzymes,Labile SOM pools,Microbial decomposition simulation model,N fertilization,Rhizosimulators,Root exudation},
month = {mar},
pages = {119--128},
publisher = {Elsevier Ltd},
title = {{Root exudates increase N availability by stimulating microbial turnover of fast-cycling N pools}},
url = {http://dx.doi.org/10.1016/j.soilbio.2016.12.004 https://linkinghub.elsevier.com/retrieve/pii/S0038071716307180},
volume = {106},
year = {2017}
}
@article{Meinshausen2009a,
abstract = {The politically defined threshold of dangerous climate change is an increase of 2 degrees Celsius in the mean global temperature. Simulations here show that when carbon dioxide and a full suite of positive and negative radiative forcings are considered, total emissions from 2000 to 2050 of about 1,400 gigatonnes of carbon dioxide yield a 50{\%} probability of exceeding this threshold by the end of the twenty-first century. 'Business as usual' emissions will probably meet or exceed this 50{\%} probability.},
author = {Meinshausen, Malte and Meinshausen, Nicolai and Hare, William and Raper, Sarah C. B. and Frieler, Katja and Knutti, Reto and Frame, David J. and Allen, Myles R.},
doi = {10.1038/nature08017},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7242},
pages = {1158--1162},
publisher = {Nature Publishing Group},
title = {{Greenhouse-gas emission targets for limiting global warming to 2°C}},
url = {http://www.nature.com/articles/nature08017},
volume = {458},
year = {2009}
}
@article{Meinshausen2011,
author = {Meinshausen, M. and Raper, S. C. B. and Wigley, T. M. L.},
doi = {10.5194/acp-11-1417-2011},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {feb},
number = {4},
pages = {1417--1456},
title = {{Emulating coupled atmosphere-ocean and carbon cycle models with a simpler model, MAGICC6 – Part 1: Model description and calibration}},
volume = {11},
year = {2011}
}
@article{Meinshausen2017,
abstract = {{\textless}p{\textgreater}{\textless}p{\textgreater}{\textless}strong{\textgreater}Abstract.{\textless}/strong{\textgreater} Atmospheric greenhouse gas (GHG) concentrations are at unprecedented, record-high levels compared to the last 800{\textless}span class="thinspace"{\textgreater}{\textless}/span{\textgreater}000 years. Those elevated GHG concentrations warm the planet and – partially offset by net cooling effects by aerosols – are largely responsible for the observed warming over the past 150 years. An accurate representation of GHG concentrations is hence important to understand and model recent climate change. So far, community efforts to create composite datasets of GHG concentrations with seasonal and latitudinal information have focused on marine boundary layer conditions and recent trends since the 1980s. Here, we provide consolidated datasets of historical atmospheric concentrations (mole fractions) of 43 GHGs to be used in the Climate Model Intercomparison Project – Phase 6 (CMIP6) experiments. The presented datasets are based on AGAGE and NOAA networks, firn and ice core data, and archived air data, and a large set of published studies. In contrast to previous intercomparisons, the new datasets are latitudinally resolved and include seasonality. We focus on the period 1850–2014 for historical CMIP6 runs, but data are also provided for the last 2000 years. We provide consolidated datasets in various spatiotemporal resolutions for carbon dioxide (CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}), methane (CH{\textless}sub{\textgreater}4{\textless}/sub{\textgreater}) and nitrous oxide (N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O), as well as 40 other GHGs, namely 17 ozone-depleting substances, 11 hydrofluorocarbons (HFCs), 9 perfluorocarbons (PFCs), sulfur hexafluoride (SF{\textless}sub{\textgreater}6{\textless}/sub{\textgreater}), nitrogen trifluoride (NF{\textless}sub{\textgreater}3{\textless}/sub{\textgreater}) and sulfuryl fluoride (SO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}F{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}). In addition, we provide three equivalence species that aggregate concentrations of GHGs other than CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}, CH{\textless}sub{\textgreater}4{\textless}/sub{\textgreater} and N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O, weighted by their radiative forcing efficiencies. For the year 1850, which is used for pre-industrial control runs, we estimate annual global-mean surface concentrations of CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater} at 284.3{\textless}span class="thinspace"{\textgreater}{\textless}/span{\textgreater}ppm, CH{\textless}sub{\textgreater}4{\textless}/sub{\textgreater} at 808.2{\textless}span class="thinspace"{\textgreater}{\textless}/span{\textgreater}ppb and N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O at 273.0{\textless}span class="thinspace"{\textgreater}{\textless}/span{\textgreater}ppb. The data are available at {\textless}a href="https://esgf-node.llnl.gov/search/input4mips/" target="{\_}blank"{\textgreater}https://esgf-node.llnl.gov/search/input4mips/{\textless}/a{\textgreater} and {\textless}a href="http://www.climatecollege.unimelb.edu.au/cmip6" target="{\_}blank"{\textgreater}http://www.climatecollege.unimelb.edu.au/cmip6{\textless}/a{\textgreater}. While the minimum CMIP6 recommendation is to{\ldots}},
author = {Meinshausen, Malte and Vogel, Elisabeth and Nauels, Alexander and Lorbacher, Katja and Meinshausen, Nicolai and Etheridge, David M. and Fraser, Paul J. and Montzka, Stephen A. and Rayner, Peter J. and Trudinger, Cathy M. and Krummel, Paul B. and Beyerle, Urs and Canadell, Josep G. and Daniel, John S. and Enting, Ian G. and Law, Rachel M. and Lunder, Chris R. and O{\&}apos;Doherty, Simon and Prinn, Ron G. and Reimann, Stefan and Rubino, Mauro and Velders, Guus J. M. and Vollmer, Martin K. and Wang, Ray H. J. and Weiss, Ray},
doi = {10.5194/gmd-10-2057-2017},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {may},
number = {5},
pages = {2057--2116},
title = {{Historical greenhouse gas concentrations for climate modelling (CMIP6)}},
volume = {10},
year = {2017}
}
@article{Meinshausen2011a,
abstract = {Abstract. Intercomparisons of coupled atmosphere-ocean general circulation models (AOGCMs) and carbon cycle models are important for galvanizing our current scientific knowledge to project future climate. Interpreting such intercomparisons faces major challenges, not least because different models have been forced with different sets of forcing agents. Here, we show how an emulation approach with MAGICC6 can address such problems. In a companion paper (Meinshausen et al., 2011a), we show how the lower complexity carbon cycle-climate model MAGICC6 can be calibrated to emulate, with considerable accuracy, globally aggregated characteristics of these more complex models. Building on that, we examine here the Coupled Model Intercomparison Project's Phase 3 results (CMIP3). If forcing agents missed by individual AOGCMs in CMIP3 are considered, this reduces ensemble average temperature change from pre-industrial times to 2100 under SRES A1B by 0.4 °C. Differences in the results from the 1980 to 1999 base period (as reported in IPCC AR4) to 2100 are negligible, however, although there are some differences in the trajectories over the 21st century. In a second part of this study, we consider the new RCP scenarios that are to be investigated under the forthcoming CMIP5 intercomparison for the IPCC Fifth Assessment Report. For the highest scenario, RCP8.5, relative to pre-industrial levels, we project a median warming of around 4.6 °C by 2100 and more than 7 °C by 2300. For the lowest RCP scenario, RCP3-PD, the corresponding warming is around 1.5 °C by 2100, decreasing to around 1.1 °C by 2300 based on our AOGCM and carbon cycle model emulations. Implied cumulative CO2 emissions over the 21st century for RCP8.5 and RCP3-PD are 1881 GtC (1697 to 2034 GtC, 80{\%} uncertainty range) and 381 GtC (334 to 488 GtC), when prescribing CO2 concentrations and accounting for uncertainty in the carbon cycle. Lastly, we assess the reasons why a previous MAGICC version (4.2) used in IPCC AR4 gave roughly 10{\%} larger warmings over the 21st century compared to the CMIP3 average. We find that forcing differences and the use of slightly too high climate sensitivities inferred from idealized high-forcing runs were the major reasons for this difference.},
author = {Meinshausen, M. and Wigley, T. M. L. and Raper, S. C. B.},
doi = {10.5194/acp-11-1457-2011},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {feb},
number = {4},
pages = {1457--1471},
title = {{Emulating atmosphere–ocean and carbon cycle models with a simpler model, MAGICC6 – Part 2: Applications}},
volume = {11},
year = {2011}
}
@article{Meinshausen2011d,
author = {Meinshausen, Malte and Smith, S. J. and Calvin, K. and Daniel, J. S. and Kainuma, M. L. T. and Lamarque, J-F. and Matsumoto, K. and Montzka, S. A. and Raper, S. C. B. and Riahi, K. and Thomson, A. and Velders, G. J. M. and van Vuuren, D.P. P.},
doi = {10.1007/s10584-011-0156-z},
issn = {0165-0009},
journal = {Climatic Change},
month = {nov},
number = {1-2},
pages = {213--241},
title = {{The RCP greenhouse gas concentrations and their extensions from 1765 to 2300}},
volume = {109},
year = {2011}
}
@article{Meinshausen2020,
abstract = {Anthropogenic increases in atmospheric greenhouse gas concentrations are the main driver of current and future climate change. The integrated assessment community has quantified anthropogenic emissions for the shared socioeconomic pathway (SSP) scenarios, each of which represents a different future socio-economic projection and political environment. Here, we provide the greenhouse gas concentrations for these SSP scenarios - using the reduced-complexity climate-carbon-cycle model MAGICC7.0.We extend historical, observationally based concentration data with SSP concentration projections from 2015 to 2500 for 43 greenhouse gases with monthly and latitudinal resolution. CO2 concentrations by 2100 range from 393 to 1135 ppm for the lowest (SSP1-1.9) and highest (SSP5-8.5) emission scenarios, respectively. We also provide the concentration extensions beyond 2100 based on assumptions regarding the trajectories of fossil fuels and land use change emissions, net negative emissions, and the fraction of non-CO 2 emissions. By 2150, CO2 concentrations in the lowest emission scenario are approximately 350 ppm and approximately plateau at that leveluntil 2500, whereas the highest fossil-fuel-driven scenario projects CO 2 concentrations of 1737 ppm and reaches concentrations beyond 2000 ppm by 2250. We estimate that the share of CO2 in the total radiative forcing contribution of all considered 43 long-lived greenhouse gases increases from 66{\%} for the present day to roughly 68{\%} to 85{\%} by the time of maximum forcing in the 21st century. For this estimation, we updated simple radiative forcing parameterizations that reflect the Oslo Line-By-Line model results. In comparison to the representative concentration pathways (RCPs), the five main SSPs (SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) are more evenly spaced and extend to lower 2100 radiative forcing and temperatures. Performing two pairs of six-member historical ensembles with CESM1.2.2, we estimate the effect on surface air temperatures of applying latitudinally and seasonally resolved GHG concentrations. We find that the ensemble differences in the March-April-May (MAM) season provide a regional warming in higher northern latitudes of up to 0.4K over the historical period, latitudinally averaged of about 0.1 K, which we estimate to be comparable to the upper bound (5{\%} level) of natural variability. In comparison to the comparatively straight line of the last 2000 years, the greenhouse gas concentrations since the onset of the industrial period and this studies' projections over the next 100 to 500 years unequivocally depict a "hockey-stick"upwards shape. The SSP concentration time series derived in this study provide a harmonized set of input assumptions for long-term climate science analysis; they also provide an indication of the wide set of futures that societal developments and policy implementations can lead to - ranging from multiple degrees of future warming on the one side to approximately 1.5 °C warming on the other.},
author = {Meinshausen, Malte and Nicholls, Zebedee R.J. and Lewis, Jared and Gidden, Matthew J. and Vogel, Elisabeth and Freund, Mandy and Beyerle, Urs and Gessner, Claudia and Nauels, Alexander and Bauer, Nico and Canadell, Josep G. and Daniel, John S. and John, Andrew and Krummel, Paul B. and Luderer, Gunnar and Meinshausen, Nicolai and Montzka, Stephen A. and Rayner, Peter J. and Reimann, Stefan and Smith, Steven J. and {Van Den Berg}, Marten and Velders, Guus J.M. and Vollmer, Martin K. and Wang, Ray H.J.},
doi = {10.5194/gmd-13-3571-2020},
issn = {19919603},
journal = {Geoscientific Model Development},
month = {aug},
number = {8},
pages = {3571--3605},
publisher = {Copernicus GmbH},
title = {{The shared socio-economic pathway (SSP) greenhouse gas concentrations and their extensions to 2500}},
volume = {13},
year = {2020}
}
@article{Meli2014,
abstract = {Wetlands are valuable ecosystems because they harbor a huge biodiversity and provide key services to societies. When natural or human factors degrade wetlands, ecological restoration is often carried out to recover biodiversity and ecosystem services (ES). Although such restorations are routinely performed, we lack systematic, evidence-based assessments of their effectiveness on the recovery of biodiversity and ES. Here we performed a meta-analysis of 70 experimental studies in order to assess the effectiveness of ecological restoration and identify what factors affect it. We compared selected ecosystem performance variables between degraded and restored wetlands and between restored and natural wetlands using response ratios and random-effects categorical modeling. We assessed how context factors such as ecosystem type, main agent of degradation, restoration action, experimental design, and restoration age influenced post-restoration biodiversity and ES. Biodiversity showed excellent recovery, though the precise recovery depended strongly on the type of organisms involved. Restored wetlands showed 36{\%} higher levels of provisioning, regulating and supporting ES than did degraded wetlands. In fact, wetlands showed levels of provisioning and cultural ES similar to those of natural wetlands; however, their levels of supporting and regulating ES were, respectively, 16{\%} and 22{\%} lower than in natural wetlands. Recovery of biodiversity and of ES were positively correlated, indicating a win-win restoration outcome. The extent to which restoration increased biodiversity and ES in degraded wetlands depended primarily on the main agent of degradation, restoration actions, experimental design, and ecosystem type. In contrast, the choice of specific restoration actions alone explained most differences between restored and natural wetlands. These results highlight the importance of comprehensive, multi-factorial assessment to determine the ecological status of degraded, restored and natural wetlands and thereby evaluate the effectiveness of ecological restorations. Future research on wetland restoration should also seek to identify which restoration actions work best for specific habitats.},
author = {Meli, Paula and {Rey Benayas}, Jos{\'{e}} Mar{\'{i}}a and Balvanera, Patricia and {Mart{\'{i}}nez Ramos}, Miguel},
doi = {10.1371/journal.pone.0093507},
issn = {1932-6203},
journal = {PLOS ONE},
language = {eng},
month = {apr},
number = {4},
pages = {e93507},
publisher = {Public Library of Science},
title = {{Restoration enhances wetland biodiversity and ecosystem service supply, but results are context-dependent: a meta-analysis}},
volume = {9},
year = {2014}
}
@article{Melillo2017,
abstract = {In a 26-year soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon cycling to investigate the potential consequences for the climate system. We found that soil warming results in a four-phase pattern of soil organic matter decay and carbon dioxide fluxes to the atmosphere, with phases of substantial soil carbon loss alternating with phases of no detectable loss. Several factors combine to affect the timing, magnitude, and thermal acclimation of soil carbon loss. These include depletion of microbially accessible carbon pools, reductions in microbial biomass, a shift in microbial carbon use efficiency, and changes in microbial community composition. Our results support projections of a long-term, self-reinforcing carbon feedback from mid-latitude forests to the climate system as the world warms.},
author = {Melillo, J M and Frey, S D and DeAngelis, K M and Werner, W J and Bernard, M J and Bowles, F P and Pold, G and Knorr, M A and Grandy, A S},
doi = {10.1126/science.aan2874},
issn = {0036-8075},
journal = {Science},
month = {oct},
number = {6359},
pages = {101--105},
title = {{Long-term pattern and magnitude of soil carbon feedback to the climate system in a warming world}},
url = {http://science.sciencemag.org/content/358/6359/101.abstract http://www.sciencemag.org/lookup/doi/10.1126/science.aan2874},
volume = {358},
year = {2017}
}
@article{Melillo2011,
abstract = {Soil warming has the potential to alter both soil and plant processes that affect carbon storage in forest ecosystems. We have quantified these effects in a large, long-term (7-y) soil-warming study in a deciduous forest in New England. Soil warming has resulted in carbon losses from the soil and stimulated carbon gains in the woody tissue of trees. The warming-enhanced decay of soil organic matter also released enough additional inorganic nitrogen into the soil solution to support the observed increases in plant carbon storage. Although soil warming has resulted in a cumulative net loss of carbon from a New England forest relative to a control area over the 7-y study, the annual net losses generally decreased over time as plant carbon storage increased. In the seventh year, warming-induced soil carbon losses were almost totally compensated for by plant carbon gains in response to warming. We attribute the plant gains primarily to warming-induced increases in nitrogen availability. This study underscores the importance of incorporating carbon-nitrogen interactions in atmosphere-ocean-land earth system models to accurately simulate land feedbacks to the climate system.},
author = {Melillo, J. M. and Butler, S. and Johnson, J. and Mohan, J. and Steudler, P. and Lux, H. and Burrows, E. and Bowles, F. and Smith, R. and Scott, L. and Vario, C. and Hill, T. and Burton, A. and Zhou, Y.-M. and Tang, J.},
doi = {10.1073/pnas.1018189108},
isbn = {0027-8424},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {jun},
number = {23},
pages = {9508--9512},
pmid = {21606374},
title = {{Soil warming, carbon–nitrogen interactions, and forest carbon budgets}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1018189108},
volume = {108},
year = {2011}
}
@article{bg-10-753-2013,
abstract = {Abstract. Global wetlands are believed to be climate sensitive, and are the largest natural emitters of methane (CH4). Increased wetland CH4 emissions could act as a positive feedback to future warming. The Wetland and Wetland CH4 Inter-comparison of Models Project (WETCHIMP) investigated our present ability to simulate large-scale wetland characteristics and corresponding CH4 emissions. To ensure inter-comparability, we used a common experimental protocol driving all models with the same climate and carbon dioxide (CO2) forcing datasets. The WETCHIMP experiments were conducted for model equilibrium states as well as transient simulations covering the last century. Sensitivity experiments investigated model response to changes in selected forcing inputs (precipitation, temperature, and atmospheric CO2 concentration). Ten models participated, covering the spectrum from simple to relatively complex, including models tailored either for regional or global simulations. The models also varied in methods to calculate wetland size and location, with some models simulating wetland area prognostically, while other models relied on remotely sensed inundation datasets, or an approach intermediate between the two. Four major conclusions emerged from the project. First, the suite of models demonstrate extensive disagreement in their simulations of wetland areal extent and CH4 emissions, in both space and time. Simple metrics of wetland area, such as the latitudinal gradient, show large variability, principally between models that use inundation dataset information and those that independently determine wetland area. Agreement between the models improves for zonally summed CH4 emissions, but large variation between the models remains. For annual global CH4 emissions, the models vary by ±40{\%} of the all-model mean (190 Tg CH4 yr−1). Second, all models show a strong positive response to increased atmospheric CO2 concentrations (857 ppm) in both CH4 emissions and wetland area. In response to increasing global temperatures (+3.4 °C globally spatially uniform), on average, the models decreased wetland area and CH4 fluxes, primarily in the tropics, but the magnitude and sign of the response varied greatly. Models were least sensitive to increased global precipitation (+3.9 {\%} globally spatially uniform) with a consistent small positive response in CH4 fluxes and wetland area. Results from the 20th century transient simulation show that interactions between climate forcings could have strong non-linear effects. Third, we presently do not have sufficient wetland methane observation datasets adequate to evaluate model fluxes at a spatial scale comparable to model grid cells (commonly 0.5°). This limitation severely restricts our ability to model global wetland CH4 emissions with confidence. Our simulated wetland extents are also difficult to evaluate due to extensive disagreements between wetland mapping and remotely sensed inundation datasets. Fourth, the large range in predicted CH4 emission rates leads to the conclusion that there is both substantial parameter and structural uncertainty in large-scale CH4 emission models, even after uncertainties in wetland areas are accounted for.},
author = {Melton, J R and Wania, R and Hodson, E L and Poulter, B and Ringeval, B and Spahni, R and Bohn, T and Avis, C A and Beerling, D J and Chen, G and Eliseev, A V and Denisov, S N and Hopcroft, P O and Lettenmaier, D P and Riley, W J and Singarayer, J S and Subin, Z M and Tian, H and Z{\"{u}}rcher, S and Brovkin, V and van Bodegom, P M and Kleinen, T and Yu, Z C and Kaplan, J O},
doi = {10.5194/bg-10-753-2013},
issn = {1726-4189},
journal = {Biogeosciences},
month = {feb},
number = {2},
pages = {753--788},
title = {{Present state of global wetland extent and wetland methane modelling: conclusions from a model inter-comparison project (WETCHIMP)}},
url = {https://www.biogeosciences.net/10/753/2013/},
volume = {10},
year = {2013}
}
@article{Mendonca2017,
abstract = {Burial in sediments removes organic carbon (OC) from the short-term biosphere-atmosphere carbon (C) cycle, and therefore prevents greenhouse gas production in natural systems. Although OC burial in lakes and reservoirs is faster than in the ocean, the magnitude of inland water OC burial is not well constrained. Here we generate the first global-scale and regionally resolved estimate of modern OC burial in lakes and reservoirs, deriving from a comprehensive compilation of literature data. We coupled statistical models to inland water area inventories to estimate a yearly OC burial of 0.15 (range, 0.06-0.25) Pg C, of which {\~{}}40{\%} is stored in reservoirs. Relatively higher OC burial rates are predicted for warm and dry regions. While we report lower burial than previously estimated, lake and reservoir OC burial corresponded to {\~{}}20{\%} of their C emissions, making them an important C sink that is likely to increase with eutrophication and river damming.},
author = {Mendon{\c{c}}a, Raquel and M{\"{u}}ller, Roger A. and Clow, David and Verpoorter, Charles and Raymond, Peter and Tranvik, Lars J. and Sobek, Sebastian},
doi = {10.1038/s41467-017-01789-6},
issn = {20411723},
journal = {Nature Communications},
number = {1},
pages = {1--6},
pmid = {29162815},
publisher = {Springer US},
title = {{Organic carbon burial in global lakes and reservoirs}},
url = {http://dx.doi.org/10.1038/s41467-017-01789-6},
volume = {8},
year = {2017}
}
@article{Menezes-Silva2019,
abstract = {Anthropogenic activities such as uncontrolled deforestation and increasing greenhouse gas emissions are responsible for triggering a series of environmental imbalances that affect the Earth's complex climate dynamics. As a consequence of these changes, several climate models forecast an intensification of extreme weather events over the upcoming decades, including heat waves and increasingly severe drought and flood episodes. The occurrence of such extreme weather will prompt profound changes in several plant communities, resulting in massive forest dieback events that can trigger a massive loss of biodiversity in several biomes worldwide. Despite the gravity of the situation, our knowledge regarding how extreme weather events can undermine the performance, survival, and distribution of forest species remains very fragmented. Therefore, the present review aimed to provide a broad and integrated perspective of the main biochemical, physiological, and morpho-anatomical disorders that may compromise the performance and survival of forest species exposed to climate change factors, particularly drought, flooding, and global warming. In addition, we also discuss the controversial effects of high CO2 concentrations in enhancing plant growth and reducing the deleterious effects of some extreme climatic events. We conclude with a discussion about the possible effects that the factors associated with the climate change might have on species distribution and forest composition.},
author = {Menezes-Silva, Paulo Eduardo and Loram-Louren{\c{c}}o, Lucas and Alves, Rauander Douglas Ferreira Barros and Sousa, Let{\'{i}}cia Ferreira and Almeida, Sabrina Emanuella da Silva and Farnese, Fernanda Santos},
doi = {10.1002/ece3.5663},
issn = {20457758},
journal = {Ecology and Evolution},
keywords = {climate change,drought,flooding,global warming,high CO2 concentration,tree mortality},
number = {20},
pages = {11979--11999},
title = {{Different ways to die in a changing world: Consequences of climate change for tree species performance and survival through an ecophysiological perspective}},
volume = {9},
year = {2019}
}
@article{Mengis2018,
abstract = {Estimates of the 1.5 °C carbon budget vary widely among recent studies, emphasizing the need to better understand and quantify key sources of uncertainty. Here we quantify the impact of carbon cycle uncertainty and non-CO2 forcing on the 1.5 °C carbon budget in the context of a prescribed 1.5 °C temperature stabilization scenario. We use Bayes theorem to weight members of a perturbed parameter ensemble with varying land and ocean carbon uptake, to derive an estimate for the fossil fuel (FF) carbon budget of 469 PgC since 1850, with a 95{\%} likelihood range of (411,528) PgC. CO2 emissions from land-use change (LUC) add about 230 PgC. Our best estimate of the total (FF + LUC) carbon budget for 1.5 °C is therefore 699 PgC, which corresponds to about 11 years of current emissions. Non-CO2 greenhouse gas and aerosol emissions represent equivalent cumulative CO2 emissions of about 510 PgC and −180 PgC for 1.5 °C, respectively. The increased LUC, high non-CO2 emissions and decreased aerosols in our scenario, cause the long-term FF carbon budget to decrease following temperature stabilization. In this scenario, negative emissions would be required to compensate not only for the increasing non-CO2 climate forcing, but also for the declining natural carbon sinks.},
author = {Mengis, Nadine and Partanen, Antti-Ilari and Jalbert, Jonathan and Matthews, H. Damon},
doi = {10.1038/s41598-018-24241-1},
issn = {2045-2322},
journal = {Scientific Reports},
keywords = {Carbon cycle,Climate and Earth system modelling,Climate change},
month = {dec},
number = {1},
pages = {5831},
publisher = {Nature Publishing Group},
title = {{1.5 °C carbon budget dependent on carbon cycle uncertainty and future non-CO2 forcing}},
url = {http://www.nature.com/articles/s41598-018-24241-1},
volume = {8},
year = {2018}
}
@article{gmd-13-4183-2020,
author = {Mengis, N and Keller, D P and MacDougall, A H and Eby, M and Wright, N and Meissner, K J and Oschlies, A and Schmittner, A and MacIsaac, A J and Matthews, H D and Zickfeld, K},
doi = {10.5194/gmd-13-4183-2020},
journal = {Geoscientific Model Development},
number = {9},
pages = {4183--4204},
title = {{Evaluation of the University of Victoria Earth System Climate Model version 2.10 (UVic ESCM 2.10)}},
url = {https://gmd.copernicus.org/articles/13/4183/2020/},
volume = {13},
year = {2020}
}
@article{Menviel2012,
abstract = {The Bern3D model was applied to quantify the mechanisms of carbon cycle changes during the Holocene (last 11,000 years). We rely on scenarios from the literature to prescribe the evolution of shallow water carbonate deposition and of land carbon inventory changes over the glacial termination (18,000 to 11,000 years ago) and the Holocene and modify these scenarios within uncertainties. Model results are consistent with Holocene records of atmospheric CO2 and $\delta$13C as well as the spatiotemporal evolution of $\delta$13C and carbonate ion concentration in the deep sea. Deposition of shallow water carbonate, carbonate compensation of land uptake during the glacial termination, land carbon uptake and release during the Holocene, and the response of the ocean-sediment system to marine changes during the termination contribute roughly equally to the reconstructed late Holocene pCO2 rise of 20 ppmv. The 5 ppmv early Holocene pCO2 decrease reflects terrestrial uptake largely compensated by carbonate deposition and ocean sediment responses. Additional small contributions arise from Holocene changes in sea surface temperature, ocean circulation, and export productivity. The Holocene pCO2 variations result from the subtle balance of forcings and processes acting on different timescales and partly in opposite direction as well as from memory effects associated with changes occurring during the termination. Different interglacial periods with different forcing histories are thus expected to yield different pCO2 evolutions as documented by ice cores.},
author = {Menviel, L. and Joos, F.},
doi = {10.1029/2011PA002224},
issn = {08838305},
journal = {Paleoceanography},
month = {mar},
number = {1},
pages = {PA1207},
title = {{Toward explaining the Holocene carbon dioxide and carbon isotope records: Results from transient ocean carbon cycle–climate simulations}},
url = {http://doi.wiley.com/10.1029/2011PA002224},
volume = {27},
year = {2012}
}
@article{RN629,
author = {Mercado, Lina M and Medlyn, Belinda E and Huntingford, Chris and Oliver, Rebecca J and Clark, Douglas B and Sitch, Stephen and Zelazowski, Przemyslaw and Kattge, Jens and Harper, Anna B and Cox, Peter M},
doi = {10.1111/nph.15100},
issn = {0028646X},
journal = {New Phytologist},
month = {jun},
number = {4},
pages = {1462--1477},
title = {{Large sensitivity in land carbon storage due to geographical and temporal variation in the thermal response of photosynthetic capacity}},
type = {Journal Article},
url = {http://doi.wiley.com/10.1111/nph.15100},
volume = {218},
year = {2018}
}
@article{Mercado2009,
abstract = {Plant photosynthesis tends to increase with irradiance. However, recent theoretical and observational studies have demonstrated that photosynthesis is also more efficient under diffuse light conditions. Changes in cloud cover or atmospheric aerosol loadings, arising from either volcanic or anthropogenic emissions, alter both the total photosynthetically active radiation reaching the surface and the fraction of this radiation that is diffuse, with uncertain overall effects on global plant productivity and the land carbon sink. Here we estimate the impact of variations in diffuse fraction on the land carbon sink using a global model modified to account for the effects of variations in both direct and diffuse radiation on canopy photosynthesis. We estimate that variations in diffuse fraction, associated largely with the 'global dimming' period, enhanced the land carbon sink by approximately one-quarter between 1960 and 1999. However, under a climate mitigation scenario for the twenty-first century in which sulphate aerosols decline before atmospheric CO(2) is stabilized, this 'diffuse-radiation' fertilization effect declines rapidly to near zero by the end of the twenty-first century.},
author = {Mercado, Lina M. and Bellouin, Nicolas and Sitch, Stephen and Boucher, Olivier and Huntingford, Chris and Wild, Martin and Cox, Peter M.},
doi = {10.1038/nature07949},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7241},
pages = {1014--1017},
pmid = {19396143},
title = {{Impact of changes in diffuse radiation on the global land carbon sink}},
url = {http://www.nature.com/articles/nature07949},
volume = {458},
year = {2009}
}
@incollection{Meredith2019,
author = {Meredith, Michael and Sommerkorn, Martin and Cassotta, Sandra and Derksen, Chris and Ekaykin, Alexey and Hollowed, Anne and Kofinas, Gary and Mackintosh, Andrew and Melbourne-Thomas, Jess and Muelbert, Mônica M.C. and Ottersen, Geir and Pritchard, Hamish and Schuur, Edward A.G.},
booktitle = {IPCC Special Report on the Ocean and Cryosphere in a Changing Climate},
editor = {Pörtner, H.-O. and Roberts, D.C. and Masson-Delmotte, V. and Zhai, P. and Tignor, M. and Poloczanska, E. and Mintenbeck, K. and Alegría, A. and Nicolai, M. and Okem, A. and Petzold, J. and Rama, B. and Weyer, N.M.},
pages = {203--320},
publisher = {In Press},
title = {{Polar Regions}},
url = {https://www.ipcc.ch/srocc/chapter/chapter-3-2},
year = {2019}
}
@article{Merlivat2018,
abstract = {Abstract. Two 3-year time series of hourly measurements of the fugacity of CO2 (fCO2) in the upper 10m of the surface layer of the northwestern Mediterranean Sea have been recorded by CARIOCA sensors almost two decades apart, in 1995–1997 and 2013–2015. By combining them with the alkalinity derived from measured temperature and salinity, we calculate changes in pH and dissolved inorganic carbon (DIC). DIC increased in surface seawater by ∼25µmolkg−1 and fCO2 by 40µatm, whereas seawater pH decreased by ∼0.04 (0.0022yr−1). The DIC increase is about 15{\%} larger than expected from the equilibrium with atmospheric CO2. This could result from natural variability, e.g. the increase between the two periods in the frequency and intensity of winter convection events. Likewise, it could be the signature of the contribution of the Atlantic Ocean as a source of anthropogenic carbon to the Mediterranean Sea through the Strait of Gibraltar. We then estimate that the part of DIC accumulated over the last 18 years represents ∼30{\%} of the total inventory of anthropogenic carbon in the Mediterranean Sea. ]]{\textgreater}},
author = {Merlivat, Liliane and Boutin, Jacqueline and Antoine, David and Beaumont, Laurence and Golbol, Melek and Vellucci, Vincenzo},
doi = {10.5194/bg-15-5653-2018},
issn = {1726-4189},
journal = {Biogeosciences},
month = {sep},
number = {18},
pages = {5653--5662},
title = {{Increase of dissolved inorganic carbon and decrease in pH in near-surface waters in the Mediterranean Sea during the past two decades}},
url = {https://www.biogeosciences.net/15/5653/2018/},
volume = {15},
year = {2018}
}
@article{Messier2019,
abstract = {Human impacts on Earth's ecosystems have greatly intensified in the last decades. This is reflected in unexpected disturbance events, as well as new and increasing socio-economic demands, all of which are affecting the resilience of forest ecosystems worldwide and the provision of important ecosystem services. This Anthropocene era is forcing us to reconsider past and current forest management and silvicultural practices, and search for new ones that are more flexible and better at dealing with the increasing uncertainty brought about by these accelerating and cumulative global changes. Here, we briefly review the focus and limitations of past and current forest management and silvicultural practices mainly as developed in Europe and North America. We then discuss some recent promising concepts, such as managing forests as complex adaptive systems, and approaches based on resilience, functional diversity, assisted migration and multi-species plantations, to propose a novel approach to integrate the functionality of species-traits into a functional complex network approach as a flexible and multi-scale way to manage forests for the Anthropocene. This approach takes into consideration the high level of uncertainty associated with future environmental and societal changes. It relies on the quantification and dynamic monitoring of functional diversity and complex network indices to manage forests as a functional complex network. Using this novel approach, the most efficient forest management and silvicultural practices can be determined, as well as where, at what scale, and at what intensity landscape-scale resistance, resilience and adaptive capacity of forests to global changes can be improved.},
author = {Messier, Christian and Bauhus, J{\"{u}}rgen and Doyon, Frederik and Maure, Fanny and Sousa-Silva, Rita and Nolet, Philippe and Mina, Marco and Aquilu{\'{e}}, N{\'{u}}ria and Fortin, Marie-Jos{\'{e}}e and Puettmann, Klaus},
doi = {10.1186/s40663-019-0166-2},
issn = {2197-5620},
journal = {Forest Ecosystems},
number = {1},
pages = {21},
title = {{The functional complex network approach to foster forest resilience to global changes}},
url = {https://doi.org/10.1186/s40663-019-0166-2},
volume = {6},
year = {2019}
}
@article{Meyer2019,
abstract = {During the last deglaciation (18-8 kyr BP), shelf flooding and warming presumably led to a large-scale decomposition of permafrost soils in the mid-to-high latitudes of the Northern Hemisphere. Microbial degradation of old organic matter released from the decomposing permafrost potentially contributed to the deglacial rise in atmospheric CO2 and also to the declining atmospheric radiocarbon contents ($\Delta$14C). The significance of permafrost for the atmospheric carbon pool is not well understood as the timing of the carbon activation is poorly constrained by proxy data. Here, we trace the mobilization of organic matter from permafrost in the Pacific sector of Beringia over the last 22 kyr using mass-accumulation rates and radiocarbon signatures of terrigenous biomarkers in four sediment cores from the Bering Sea and the Northwest Pacific. We find that pronounced reworking and thus the vulnerability of old organic carbon to remineralization commenced during the early deglaciation (∼16.8 kyr BP) when meltwater runoff in the Yukon River intensified riverbank erosion of permafrost soils and fluvial discharge. Regional deglaciation in Alaska additionally mobilized significant fractions of fossil, petrogenic organic matter at this time. Permafrost decomposition across Beringia's Pacific sector occurred in two major pulses that match the Bolling-Allerod and Preboreal warm spells and rapidly initiated within centuries. The carbon mobilization likely resulted from massive shelf flooding during meltwater pulses 1A (∼14.6 kyr BP) and 1B (∼11.5 kyr BP) followed by permafrost thaw in the hinterland. Our findings emphasize that coastal erosion was a major control to rapidly mobilize permafrost carbon along Beringia's Pacific coast at ∼14.6 and ∼11.5 kyr BP implying that shelf flooding in Beringia may partly explain the centennial-scale rises in atmospheric CO2 at these times. Around 16.5 kyr BP, the mobilization of old terrigenous organic matter caused by meltwater-floods may have additionally contributed to increasing CO2 levels.},
author = {Meyer, Vera D. and Hefter, Jens and K{\"{o}}hler, Peter and Tiedemann, Ralf and Gersonde, Rainer and Wacker, Lukas and Mollenhauer, Gesine},
doi = {10.1088/1748-9326/ab2653},
issn = {17489326},
journal = {Environmental Research Letters},
keywords = {Bering Sea,Beringia,Northwest Pacific,atmospheric CO2,biomarker,deglaciation,permafrost decomposition},
number = {8},
pages = {085003},
publisher = {IOP Publishing},
title = {{Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming}},
volume = {14},
year = {2019}
}
@article{Meyerholt2020,
author = {Meyerholt, Johannes and Sickel, Kerstin and Zaehle, S{\"{o}}nke},
doi = {10.1111/gcb.15114},
issn = {1354-1013},
journal = {Global Change Biology},
month = {jul},
number = {7},
pages = {3978--3996},
title = {{Ensemble projections elucidate effects of uncertainty in terrestrial nitrogen limitation on future carbon uptake}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.15114},
volume = {26},
year = {2020}
}
@article{Middelburg2009,
author = {Middelburg, J J and Levin, L A},
doi = {10.5194/bg-6-1273-2009},
journal = {Biogeosciences},
number = {7},
pages = {1273--1293},
title = {{Coastal hypoxia and sediment biogeochemistry}},
volume = {6},
year = {2009}
}
@article{Midorikawa2012b,
abstract = {The Southern Ocean is an important region for investigation because it has a major effect on global air-to-sea CO2 fluxes and because of the ocean acidification resulting from the uptake of anthropogenic carbon, leading to serious consequences for marine ecosystems in the near future. We estimated long-term trends of ocean acidification in surface waters of the Pacific sector of the Southern Ocean, based on the summer observational records of oceanic CO2 partial pressure and related surface properties during 1969–2003. The computed pH time series exhibited substantial decreasing trends in the extensive region from the subtropical to polar zones. The mean rates of pH decrease over the 35-year period were 0.0011 to 0.0013yr−1 in the zones north of the Polar Front and were larger in the polar zone (0.0020yr−1). The contribution of trends in sea surface temperature to the trends of pH decrease was small in all zones. The high rate of pH decrease in the polar zone was attributed to the supply of dissolved inorganic carbon from lower layers, enhanced by intensified wind stress and superimposed onto the accumulation of anthropogenic CO2. A preliminary evaluation of thermodynamic changes in the upper carbonate system, using observational results, projected that the polar zone south of the Polar Front would be undersaturated with respect to aragonite in summer after 80 years.},
author = {Midorikawa, Takashi and Inoue, Hisayuki Y and Ishii, Masao and Sasano, Daisuke and Kosugi, Naohiro and Hashida, Gen and Nakaoka, Shin-ichiro and Suzuki, Toru},
doi = {10.1016/j.dsr.2011.12.003},
issn = {09670637},
journal = {Deep Sea Research Part I: Oceanographic Research Papers},
keywords = {Long-term trend,Ocean acidification,Ocean carbon sink,Oceanic CO partial pressure,Southern Ocean,pH},
month = {mar},
pages = {131--139},
title = {{Decreasing pH trend estimated from 35-year time series of carbonate parameters in the Pacific sector of the Southern Ocean in summer}},
url = {http://www.sciencedirect.com/science/article/pii/S0967063711002354 https://linkinghub.elsevier.com/retrieve/pii/S0967063711002354},
volume = {61},
year = {2012}
}
@article{Millar2018,
abstract = {The historical observational record offers a way to constrain the relationship between cumulative carbon dioxide emissions and global mean warming. We use a standard detection and attribution technique, along with observational uncertainties to estimate the all-forcing or ‘effective' transient climate response to cumulative emissions (TCRE) from the observational record. Accounting for observational uncertainty and uncertainty in historical non-CO2 radiative forcing gives a best-estimate from the historical record of 1.84°C/TtC (1.43–2.37°C/TtC 5–95{\%} uncertainty) for the effective TCRE and 1.31°C/TtC (0.88–2.60°C/TtC 5–95{\%} uncertainty) for the CO2-only TCRE. While the best-estimate TCRE lies in the lower half of the IPCC likely range, the high upper bound is associated with the not-ruled-out possibility of a strongly negative aerosol forcing. Earth System Models have a higher effective TCRE range when compared like-for-like with the observations over the historical period, associated in part with a slight underestimate of diagnosed cumulative emissions relative to the observational best-estimate, a larger ensemble mean-simulated CO2-induced warming, and rapid post-2000 non-CO2 warming in some ensemble members.This article is part of the theme issue ‘The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels{\&}{\#}039;.},
author = {Millar, Richard J. and Friedlingstein, Pierre},
doi = {10.1098/rsta.2016.0449},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
keywords = {Carbon budgets,Carbon cycle,Climate change,Paris agreement},
month = {may},
number = {2119},
pages = {20160449},
pmid = {29610381},
title = {{The utility of the historical record for assessing the transient climate response to cumulative emissions}},
url = {http://rsta.royalsocietypublishing.org/lookup/doi/10.1098/rsta.2016.0449},
volume = {376},
year = {2018}
}
@article{Millar2017b,
abstract = {If CO2 emissions after 2015 do not exceed 200 GtC, climate warming after 2015 will fall below 0.6 °C in 66{\%} of CMIP5 models, according to an analysis based on combining a simple climate–carbon-cycle model with estimated ranges for key climate system properties.},
author = {Millar, Richard J. and Fuglestvedt, Jan S. and Friedlingstein, Pierre and Rogelj, Joeri and Grubb, Michael J. and Matthews, H. Damon and Skeie, Ragnhild B. and Forster, Piers M. and Frame, David J. and Allen, Myles R.},
doi = {10.1038/ngeo3031},
issn = {1752-0894},
journal = {Nature Geoscience},
keywords = {Climate,Climate and Earth system modelling,change mitigation},
month = {oct},
number = {10},
pages = {741--747},
publisher = {Nature Publishing Group},
title = {{Emission budgets and pathways consistent with limiting warming to 1.5 °C}},
url = {http://www.nature.com/doifinder/10.1038/ngeo3031 http://www.nature.com/articles/ngeo3031},
volume = {10},
year = {2017}
}
@article{Millar2017,
abstract = {{\textless}p{\textgreater}Abstract. Projections of the response to anthropogenic emission scenarios, evaluation of some greenhouse gas metrics, and estimates of the social cost of carbon often require a simple model that links emissions of carbon dioxide (CO2) to atmospheric concentrations and global temperature changes. An essential requirement of such a model is to reproduce typical global surface temperature and atmospheric CO2 responses displayed by more complex Earth system models (ESMs) under a range of emission scenarios, as well as an ability to sample the range of ESM response in a transparent, accessible and reproducible form. Here we adapt the simple model of the Intergovernmental Panel on Climate Change 5th Assessment Report (IPCC AR5) to explicitly represent the state dependence of the CO2 airborne fraction. Our adapted model (FAIR) reproduces the range of behaviour shown in full and intermediate complexity ESMs under several idealised carbon pulse and exponential concentration increase experiments. We find that the inclusion of a linear increase in 100-year integrated airborne fraction with cumulative carbon uptake and global temperature change substantially improves the representation of the response of the climate system to CO2 on a range of timescales and under a range of experimental designs.{\textless}/p{\textgreater}},
author = {Millar, Richard J. and Nicholls, Zebedee R. and Friedlingstein, Pierre and Allen, Myles R.},
doi = {10.5194/acp-17-7213-2017},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {jun},
number = {11},
pages = {7213--7228},
publisher = {Copernicus GmbH},
title = {{A modified impulse-response representation of the global near-surface air temperature and atmospheric concentration response to carbon dioxide emissions}},
url = {https://acp.copernicus.org/articles/17/7213/2017/},
volume = {17},
year = {2017}
}
@article{Miller2019,
author = {Miller, Scot M. and Michalak, Anna M. and Detmers, Robert G. and Hasekamp, Otto P. and Bruhwiler, Lori M. P. and Schwietzke, Stefan},
doi = {10.1038/s41467-018-07891-7},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {303},
title = {{China's coal mine methane regulations have not curbed growing emissions}},
url = {http://www.nature.com/articles/s41467-018-07891-7},
volume = {10},
year = {2019}
}
@article{Millero2009,
author = {Millero, Frank and Woosley, Ryan and DiTrolio, Benjamin and Waters, Jason},
doi = {10.5670/oceanog.2009.98},
issn = {10428275},
journal = {Oceanography},
month = {dec},
number = {4},
pages = {72--85},
title = {{Effect of Ocean Acidification on the Speciation of Metals in Seawater}},
url = {http://www.tos.org/oceanography/archive/22-4{\_}millero.html https://tos.org/oceanography/article/effect-of-ocean-acidification-on-the-speciation-of-metals-in-seawater},
volume = {22},
year = {2009}
}
@article{Milly2016,
abstract = {By various measures (drought area and intensity, climatic aridity index, and climatic water deficits), some observational analyses have suggested that much of the Earth's land has been drying during recent decades, but such drying seems inconsistent with observations of dryland greening and decreasing pan evaporation. 'Offline' analyses of climate-model outputs from anthropogenic climate change (ACC) experiments portend continuation of putative drying through the twenty-first century, despite an expected increase in global land precipitation. A ubiquitous increase in estimates of potential evapotranspiration (PET), driven by atmospheric warming, underlies the drying trends, but may be a methodological artefact. Here we show that the PET estimator commonly used (the Penman-Monteith PET for either an open-water surface or a reference crop) severely overpredicts the changes in non-water-stressed evapotranspiration computed in the climate models themselves in ACC experiments. This overprediction is partially due to neglect of stomatal conductance reductions commonly induced by increasing atmospheric CO2 concentrations in climate models. Our findings imply that historical and future tendencies towards continental drying, as characterized by offline-computed runoff, as well as other PET-dependent metrics, may be considerably weaker and less extensive than previously thought.},
author = {Milly, P. C.D. and Dunne, K. A.},
doi = {10.1038/nclimate3046},
issn = {17586798},
journal = {Nature Climate Change},
number = {10},
pages = {946--949},
title = {{Potential evapotranspiration and continental drying}},
volume = {6},
year = {2016}
}
@article{Minschwaner1993,
abstract = {An accurate line‐by‐line model is used to evaluate effects of absorption in the Schumann‐Runge bands of O2 on transmission of ultraviolet radiation. Allowing also for absorption in the Herzberg continuum, the model is shown to provide a reliable simulation of observed transmission in the spectral interval 192 to 200 nm. The model is used to evaluate rates for photolysis of N2O, CFCl3, and CF2Cl2, and to infer global loss rates (1.22×l010 kg N yr−1, 7.21×107 and 3.04×l07 kg Cl yr−1, respectively) and instantaneous lifetimes (123, 44, and 116 years, respectively) appropriate for 1980. A parameterized version of the line‐by‐line model enabling rapid evaluation of transmission in the Schumann‐Runge region is described. Photochemical calculations employing the parameterization and constrained by data from the Atmospheric Trace Molecule Spectroscopy experiment are used to examine the budget of odd oxygen. Consistent with previous studies, it is shown that photochemical loss of odd oxygen exceeds production by photolysis of O2 for altitudes above 40 km. The imbalance between production and loss is shown to be consistent with a source of odd oxygen proportional to the product of the mixing ratio and photolysis rate of ozone, which suggests that processes involving vibrationally excited O2 may play an important role in production of odd oxygen.},
author = {Minschwaner, K. and Salawitch, R. J. and McElroy, M. B.},
doi = {10.1029/93JD00223},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jun},
number = {D6},
pages = {10543},
publisher = {Wiley-Blackwell},
title = {{Absorption of solar radiation by O2: Implications for O3 and lifetimes of N2O, CFCl3, and CF2Cl2}},
url = {http://doi.wiley.com/10.1029/93JD00223},
volume = {98},
year = {1993}
}
@article{Minshull2016,
abstract = {Abstract During the Paleocene-Eocene Thermal Maximum (PETM), the carbon isotopic signature ($\delta$13C) of surface carbon-bearing phases decreased abruptly by at least 2.5 to 3.0‰. This carbon isotope excursion (CIE) has been attributed to widespread methane hydrate dissociation in response to rapid ocean warming. We ran a thermohydraulic modeling code to simulate hydrate dissociation due to ocean warming for various PETM scenarios. Our results show that hydrate dissociation in response to such warming can be rapid but suggest that methane release to the ocean is modest and delayed by hundreds to thousands of years after the onset of dissociation, limiting the potential for positive feedback from emission-induced warming. In all of our simulations at least half of the dissociated hydrate methane remains beneath the seabed, suggesting that the pre-PETM hydrate inventory needed to account for all of the CIE is at least double that required for isotopic mass balance.},
author = {Minshull, T A and Mar{\'{i}}n-Moreno, H and {Armstrong McKay}, D I and Wilson, P A},
doi = {10.1002/2016GL069676},
journal = {Geophysical Research Letters},
number = {16},
pages = {8637--8644},
title = {{Mechanistic insights into a hydrate contribution to the Paleocene-Eocene carbon cycle perturbation from coupled thermohydraulic simulations}},
volume = {43},
year = {2016}
}
@article{Mishra2020,
abstract = {Large stocks of soil organic carbon (SOC) have accumulated in the Northern Hemisphere permafrost region, but their current amounts and future fate remain uncertain. By analyzing dataset combining {\textgreater}2700 soil profiles with environmental variables in a geospatial framework, we generated spatially explicit estimates of permafrost-region SOC stocks, quantified spatial heterogeneity, and identified key environmental predictors. We estimated that 1014 − 175 + 194 Pg C are stored in the top 3 m of permafrost region soils. The greatest uncertainties occurred in circumpolar toe-slope positions and in flat areas of the Tibetan region. We found that soil wetness index and elevation are the dominant topographic controllers and surface air temperature (circumpolar region) and precipitation (Tibetan region) are significant climatic controllers of SOC stocks. Our results provide first high-resolution geospatial assessment of permafrost region SOC stocks and their relationships with environmental factors, which are crucial for modeling the response of permafrost affected soils to changing climate.},
author = {Mishra, Umakant and Hugelius, Gustaf and Shelef, Eitan and Yang, Yuanhe and Strauss, Jens and Lupachev, Alexey and Harden, Jennifer W. and Jastrow, Julie D. and Ping, Chien-Lu and Riley, William J. and Schuur, Edward A. G. and Matamala, Roser and Siewert, Matthias and Nave, Lucas E. and Koven, Charles D. and Fuchs, Matthias and Palmtag, Juri and Kuhry, Peter and Treat, Claire C. and Zubrzycki, Sebastian and Hoffman, Forrest M. and Elberling, Bo and Camill, Philip and Veremeeva, Alexandra and Orr, Andrew},
doi = {10.1126/sciadv.aaz5236},
issn = {2375-2548},
journal = {Science Advances},
month = {feb},
number = {9},
pages = {eaaz5236},
title = {{Spatial heterogeneity and environmental predictors of permafrost region soil organic carbon stocks}},
url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aaz5236},
volume = {7},
year = {2021}
}
@article{Moffitt2015a,
abstract = {Anthropogenic climate change is predicted to decrease oceanic oxygen (O2) concentrations, with potentially significant effects on marine ecosystems. Geologically recent episodes of abrupt climatic warming provide opportunities to assess the effects of changing oxygenation on marine communities. Thus far, this knowledge has been largely restricted to investigations using Foraminifera, with little being known about ecosystem-scale responses to abrupt, climate-forced deoxygenation. We here present high-resolution records based on the first comprehensive quantitative analysis, to our knowledge, of changes in marine metazoans (Mollusca, Echinodermata, Arthropoda, and Annelida; {\textgreater}5,400 fossils and trace fossils) in response to the global warming associated with the last glacial to interglacial episode. The molluscan archive is dominated by extremophile taxa, including those containing endosymbiotic sulfur-oxidizing bacteria (Lucinoma aequizonatum) and those that graze on filamentous sulfur-oxidizing benthic bacterial mats (Alia permodesta). This record, from 16,100 to 3,400 y ago, demonstrates that seafloor invertebrate communities are subject to major turnover in response to relatively minor inferred changes in oxygenation ({\textgreater}1.5 to {\textless}0.5 mL⋅L(-1) [O2]) associated with abrupt ({\textless}100 y) warming of the eastern Pacific. The biotic turnover and recovery events within the record expand known rates of marine biological recovery by an order of magnitude, from {\textless}100 to {\textgreater}1,000 y, and illustrate the crucial role of climate and oceanographic change in driving long-term successional changes in ocean ecosystems.},
author = {Moffitt, Sarah E. and Hill, Tessa M. and Roopnarine, Peter D. and Kennett, James P.},
doi = {10.1073/pnas.1417130112},
isbn = {1091-6490 (Electronic) 0027-8424 (Linking)},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {apr},
number = {15},
pages = {4684--4689},
pmid = {25825727},
title = {{Response of seafloor ecosystems to abrupt global climate change}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1417130112},
volume = {112},
year = {2015}
}
@article{Mongwe2018a,
abstract = {Abstract. The Southern Ocean forms an important component of the Earth system as a major sink of CO2 and heat. Recent studies based on the Coupled Model Intercomparison Project version 5 (CMIP5) Earth system models (ESMs) show that CMIP5 models disagree on the phasing of the seasonal cycle of the CO2 flux (FCO2) and compare poorly with available observation products for the Southern Ocean. Because the seasonal cycle is the dominant mode of CO2 variability in the Southern Ocean, its simulation is a rigorous test for models and their long-term projections. Here we examine the competing roles of temperature and dissolved inorganic carbon (DIC) as drivers of the seasonal cycle of pCO2 in the Southern Ocean to explain the mechanistic basis for the seasonal biases in CMIP5 models. We find that despite significant differences in the spatial characteristics of the mean annual fluxes, the intra-model homogeneity in the seasonal cycle of FCO2 is greater than observational products. FCO2 biases in CMIP5 models can be grouped into two main categories, i.e., group-SST and group-DIC. Group-SST models show an exaggeration of the seasonal rates of change of sea surface temperature (SST) in autumn and spring during the cooling and warming peaks. These higher-than-observed rates of change of SST tip the control of the seasonal cycle of pCO2 and FCO2 towards SST and result in a divergence between the observed and modeled seasonal cycles, particularly in the Sub-Antarctic Zone. While almost all analyzed models (9 out of 10) show these SST-driven biases, 3 out of 10 (namely NorESM1-ME, HadGEM-ES and MPI-ESM, collectively the group-DIC models) compensate for the solubility bias because of their overly exaggerated primary production, such that biologically driven DIC changes mainly regulate the seasonal cycle of FCO2. ]]{\textgreater}},
author = {Mongwe, N. Precious and Vichi, Marcello and Monteiro, Pedro M. S.},
doi = {10.5194/bg-15-2851-2018},
issn = {1726-4189},
journal = {Biogeosciences},
month = {may},
number = {9},
pages = {2851--2872},
title = {{The seasonal cycle of pCO2 and CO2 fluxes in the Southern Ocean: diagnosing anomalies in CMIP5 Earth system models}},
url = {https://www.biogeosciences.net/15/2851/2018/},
volume = {15},
year = {2018}
}
@article{Monnin2001,
abstract = {A record of atmospheric carbon dioxide (CO2) concentration during the transition from the Last Glacial Maximum to the Holocene, obtained from the Dome Concordia, Antarctica, ice core, reveals that an increase of 76 parts per million by volume occurred over a period of 6000 years in four clearly distinguishable intervals. The close correlation between CO2 concentration and Antarctic temperature indicates that the Southern Ocean played an important role in causing the CO2 increase. However, the similarity of changes in CO2 concentration and variations of atmospheric methane concentration suggests that processes in the tropics and in the Northern Hemisphere, where the main sources for methane are located, also had substantial effects on atmospheric CO2 concentrations.},
author = {Monnin, Eric},
doi = {10.1126/science.291.5501.112},
issn = {00368075},
journal = {Science},
month = {jan},
number = {5501},
pages = {112--114},
publisher = {American Association for the Advancement of Science},
title = {{Atmospheric CO2 Concentrations over the Last Glacial Termination}},
url = {http://science.sciencemag.org/content/291/5501/112 http://www.sciencemag.org/cgi/doi/10.1126/science.291.5501.112},
volume = {291},
year = {2001}
}
@article{Monteiro2020a,
abstract = {We show an annual overview of the sea-air CO 2 exchanges and primary drivers in the Gerlache Strait, a hotspot for climate change that is ecologically important in the northern Antarctic Peninsula. In autumn and winter, episodic upwelling events increase the remineralized carbon in the sea surface, leading the region to act as a moderate or strong CO 2 source to the atmosphere of up to 40 mmol m –2 day –1 . During summer and late spring, photosynthesis decreases the CO 2 partial pressure in the surface seawater, enhancing ocean CO 2 uptake, which reaches values higher than − 40 mmol m –2 day –1 . Thus, autumn/winter CO 2 outgassing is nearly balanced by an only 4-month period of intense ocean CO 2 ingassing during summer/spring. Hence, the estimated annual net sea-air CO 2 flux from 2002 to 2017 was 1.24 ± 4.33 mmol m –2 day –1 , opposing the common CO 2 sink behaviour observed in other coastal regions around Antarctica. The main drivers of changes in the surface CO 2 system in this region were total dissolved inorganic carbon and total alkalinity, revealing dominant influences of both physical and biological processes. These findings demonstrate the importance of Antarctica coastal zones as summer carbon sinks and emphasize the need to better understand local/regional seasonal sensitivity to the net CO 2 flux effect on the Southern Ocean carbon cycle, especially considering the impacts caused by climate change.},
author = {Monteiro, Thiago and Kerr, Rodrigo and Machado, Eunice da Costa},
doi = {10.1038/s41598-020-71814-0},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {14875},
title = {{Seasonal variability of net sea–air CO2 fluxes in a coastal region of the northern Antarctic Peninsula}},
volume = {10},
year = {2020}
}
@article{Monteiro2020b,
abstract = {The Southern Ocean is a globally important carbon sink region. However, the austral coastal zones are usually not considered in global estimations due to their general undersampling and large regional dynamics. Thus, estimations of carbon uptake in the Southern Ocean may differ considerably from current values, i.e., without accounting for coastal regions. Here, we conducted a case study in the Gerlache Strait, an ecologically important Antarctic coastal zone. We show that the net sea-air CO2 flux (FCO2) in the strait may reach the same or greater magnitudes than those in large open sea regions around Antarctica during summer, despite having a much smaller area. A large mean FCO2 of -31 +/- 19 mmol m(-2) d(-1) was observed in the strong CO2 sink years (i.e., FCO2 {\textless} -12 mmol m(-2) d(-1)), in contrast to -1 +/- 7 mmol m(-2) d(-1 )in CO(2 )near-equilibrium conditions (i.e., CO(2 )sea-air difference approximate to 0). This variability is mainly modulated by phytoplankton activity and likely upwelling processes. We also identified two cycles of variability with 2-year and 4-year periodicities from 1999 to 2017. The 2-year periodicity becomes stronger after 2012, intensifying the strong CO2 sink scenario in the Gerlache Strait. Our findings reinforce the importance of polar coastal zones as CO(2 )sinks during the austral summer and the need to broaden our understanding of the role of these regions at other time scales.},
author = {Monteiro, Thiago and Kerr, Rodrigo and Orselli, Iole B.M. and Lencina-Avila, Jannine M},
doi = {10.1016/j.pocean.2020.102267},
issn = {00796611},
journal = {Progress in Oceanography},
month = {apr},
pages = {102267},
title = {{Towards an intensified summer CO2 sink behaviour in the Southern Ocean coastal regions}},
volume = {183},
year = {2020}
}
@article{Moy2019,
abstract = {Glacial–interglacial changes in atmospheric CO2 are generally attributed to changes in seawater carbon chemistry in response to large-scale shifts in the ocean's biogeochemistry and general circulation. The Southern Ocean currently takes up more CO2 than any other and it is likely to have played a crucial role in regulating past atmospheric CO2. However, the physical, biological and chemical variables that control ocean–atmosphere CO2 exchange during glacial–interglacial cycles are not completely understood. Here we use boron isotopes and carbon isotopes in planktonic foraminifera and an alkenone-based proxy of temperature to reconstruct seawater pH and CO2 partial pressure in sub-Antarctic surface waters south of Tasmania over the past 25,000 years, and investigate the mechanisms that regulate seawater CO2. The new record shows that surface waters in this region were a sink for atmospheric CO2 during the Last Glacial Maximum. Our reconstruction suggests changes in the strength of the biological pump and the release of deep-ocean CO2 to surface waters contributed to the last deglacial rise in atmospheric CO2. These findings demonstrate that variations in upwelling intensity and the distribution of Southern Ocean water masses in this sector played a key role in regulating atmospheric CO2 during the last glacial–interglacial cycle.},
author = {Moy, Andrew D. and Palmer, Martin R. and Howard, William R. and Bijma, Jelle and Cooper, Matthew J. and Calvo, Eva and Pelejero, Carles and Gagan, Michael K. and Chalk, Thomas B.},
doi = {10.1038/s41561-019-0473-9},
issn = {17520908},
journal = {Nature Geoscience},
number = {12},
pages = {1006--1011},
publisher = {Springer US},
title = {{Varied contribution of the Southern Ocean to deglacial atmospheric CO2 rise}},
url = {http://dx.doi.org/10.1038/s41561-019-0473-9},
volume = {12},
year = {2019}
}
@article{Muri2018,
abstract = {AbstractConsidering the ambitious climate targets of the Paris Agreement to limit global warming to 2 °C, with aspirations of even 1.5 °C, questions arise on how to achieve this. Climate geoengineering has been proposed as a potential tool to minimise global harm from anthropogenic climate change. Here, an Earth System model is used to evaluate the climate response when transferring from a high CO2 forcing scenario, RCP8.5, to a middle-of-the-road forcing scenario, like RCP4.5, using aerosol geoengineering. Three different techniques are considered: stratospheric aerosol injections (SAI), marine sky brightening (MSB) and cirrus cloud thinning (CCT). The climate states appearing in the climate geoengineering cases are found to be closer to RCP4.5 than RCP8.5 and many anthropogenic global warming symptoms are alleviated. All three techniques result in comparable global mean temperature evolutions. However, there are some notable differences in other climate variables due to the nature of the forcings applie...},
author = {Muri, Helene and Tjiputra, Jerry and Otter{\aa}, Odd Helge and Adakudlu, Muralidhar and Lauvset, Siv K. and Grini, Alf and Schulz, Michael and Niemeier, Ulrike and Kristj{\'{a}}nsson, J{\'{o}}n Egill},
doi = {10.1175/JCLI-D-17-0620.1},
issn = {08948755},
journal = {Journal of Climate},
number = {16},
pages = {6319--6340},
title = {{Climate response to aerosol geoengineering: A multimethod comparison}},
volume = {31},
year = {2018}
}
@article{Murray2015,
abstract = {Abstract Nitrous oxide is a powerful, long-lived greenhouse gas, but we know little about the role of estuarine areas in the global N2O budget. This review summarizes 56 studies of N2O fluxes and associated biogeochemical controlling factors in estuarine open waters, salt marshes, mangroves, and intertidal sediments. The majority of in situ N2O production occurs as a result of sediment denitrification, although the water column contributes N2O through nitrification in suspended particles. The most important factors controlling N2O fluxes seem to be dissolved inorganic nitrogen (DIN) and oxygen availability, which in turn are affected by tidal cycles, groundwater inputs, and macrophyte density. The heterogeneity of coastal environments leads to a high variability in observations, but on average estuarine open water, intertidal and vegetated environments are sites of a small positive N2O flux to the atmosphere (range 0.15?0.91; median 0.31; Tg N2O-N yr?1). Global changes in macrophyte distribution and anthropogenic nitrogen loading are expected to increase N2O emissions from estuaries. We estimate that a doubling of current median NO3? concentrations would increase the global estuary water?air N2O flux by about 0.45 Tg N2O-N yr?1 or about 190{\%}. A loss of 50{\%} of mangrove habitat, being converted to unvegetated intertidal area, would result in a net decrease in N2O emissions of 0.002 Tg N2O-N yr?1. In contrast, conversion of 50{\%} of salt marsh to unvegetated area would result in a net increase of 0.001 Tg N2O-N yr?1. Decreased oxygen concentrations may inhibit production of N2O by nitrification; however, sediment denitrification and the associated ratio of N2O:N2 is expected to increase.},
annote = {doi: 10.1111/gcb.12923},
author = {Murray, Rachel H and Erler, Dirk V and Eyre, Bradley D},
doi = {10.1111/gcb.12923},
issn = {13541013},
journal = {Global Change Biology},
keywords = {denitrification,estuary,greenhouse gas,intertidal,mangrove,mudflat,nitrous oxide,salt marsh},
month = {sep},
number = {9},
pages = {3219--3245},
publisher = {John Wiley {\&} Sons, Ltd (10.1111)},
title = {{Nitrous oxide fluxes in estuarine environments: response to global change}},
url = {https://doi.org/10.1111/gcb.12923 http://doi.wiley.com/10.1111/gcb.12923},
volume = {21},
year = {2015}
}
@article{Myers_Smith_2011,
abstract = {Recent research using repeat photography, long-term ecological monitoring and dendrochronology has documented shrub expansion in arctic, high-latitude and alpine tundra ecosystems. Here, we (1) synthesize these findings, (2) present a conceptual framework that identifies mechanisms and constraints on shrub increase, (3) explore causes, feedbacks and implications of the increased shrub cover in tundra ecosystems, and (4) address potential lines of investigation for future research. Satellite observations from around the circumpolar Arctic, showing increased productivity, measured as changes in ‘greenness', have coincided with a general rise in high-latitude air temperatures and have been partly attributed to increases in shrub cover. Studies indicate that warming temperatures, changes in snow cover, altered disturbance regimes as a result of permafrost thaw, tundra fires, and anthropogenic activities or changes in herbivory intensity are all contributing to observed changes in shrub abundance. A large-scale increase in shrub cover will change the structure of tundra ecosystems and alter energy fluxes, regional climate, soil–atmosphere exchange of water, carbon and nutrients, and ecological interactions between species. In order to project future rates of shrub expansion and understand the feedbacks to ecosystem and climate processes, future research should investigate the species or trait-specific responses of shrubs to climate change including: (1) the temperature sensitivity of shrub growth, (2) factors controlling the recruitment of new individuals, and (3) the relative influence of the positive and negative feedbacks involved in shrub expansion.},
author = {Myers-Smith, Isla H and Forbes, Bruce C and Wilmking, Martin and Hallinger, Martin and Lantz, Trevor and Blok, Daan and Tape, Ken D and Macias-Fauria, Marc and Sass-Klaassen, Ute and L{\'{e}}vesque, Esther and Boudreau, St{\'{e}}phane and Ropars, Pascale and Hermanutz, Luise and Trant, Andrew and Collier, Laura Siegwart and Weijers, Stef and Rozema, Jelte and Rayback, Shelly A and Schmidt, Niels Martin and Schaepman-Strub, Gabriela and Wipf, Sonja and Rixen, Christian and M{\'{e}}nard, C{\'{e}}cile B and Venn, Susanna and Goetz, Scott and Andreu-Hayles, Laia and Elmendorf, Sarah and Ravolainen, Virve and Welker, Jeffrey and Grogan, Paul and Epstein, Howard E and Hik, David S},
doi = {10.1088/1748-9326/6/4/045509},
journal = {Environmental Research Letters},
month = {dec},
number = {4},
pages = {45509},
publisher = {{\{}IOP{\}} Publishing},
title = {{Shrub expansion in tundra ecosystems: dynamics, impacts and research priorities}},
url = {https://doi.org/10.1088{\%}2F1748-9326{\%}2F6{\%}2F4{\%}2F045509},
volume = {6},
year = {2011}
}
@article{Naik2013,
abstract = {Abstract. We have analysed time-slice simulations from 17 global models, participating in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), to explore changes in present-day (2000) hydroxyl radical (OH) concentration and methane (CH4) lifetime relative to preindustrial times (1850) and to 1980. A comparison of modeled and observation-derived methane and methyl chloroform lifetimes suggests that the present-day global multi-model mean OH concentration is overestimated by 5 to 10{\%} but is within the range of uncertainties. The models consistently simulate higher OH concentrations in the Northern Hemisphere (NH) compared with the Southern Hemisphere (SH) for the present-day (2000; inter-hemispheric ratios of 1.13 to 1.42), in contrast to observation-based approaches which generally indicate higher OH in the SH although uncertainties are large. Evaluation of simulated carbon monoxide (CO) concentrations, the primary sink for OH, against ground-based and satellite observations suggests low biases in the NH that may contribute to the high north–south OH asymmetry in the models. The models vary widely in their regional distribution of present-day OH concentrations (up to 34{\%}). Despite large regional changes, the multi-model global mean (mass-weighted) OH concentration changes little over the past 150 yr, due to concurrent increases in factors that enhance OH (humidity, tropospheric ozone, nitrogen oxide (NOx) emissions, and UV radiation due to decreases in stratospheric ozone), compensated by increases in OH sinks (methane abundance, carbon monoxide and non-methane volatile organic carbon (NMVOC) emissions). The large inter-model diversity in the sign and magnitude of preindustrial to present-day OH changes (ranging from a decrease of 12.7{\%} to an increase of 14.6{\%}) indicate that uncertainty remains in our understanding of the long-term trends in OH and methane lifetime. We show that this diversity is largely explained by the different ratio of the change in global mean tropospheric CO and NOx burdens ($\Delta$CO/$\Delta$NOx, approximately represents changes in OH sinks versus changes in OH sources) in the models, pointing to a need for better constraints on natural precursor emissions and on the chemical mechanisms in the current generation of chemistry-climate models. For the 1980 to 2000 period, we find that climate warming and a slight increase in mean OH (3.5 ± 2.2{\%}) leads to a 4.3 ± 1.9{\%} decrease in the methane lifetime. Analysing sensitivity simulations performed by 10 models, we find that preindustrial to present-day climate change decreased the methane lifetime by about four months, representing a negative feedback on the climate system. Further, we analysed attribution experiments performed by a subset of models relative to 2000 conditions with only one precursor at a time set to 1860 levels. We find that global mean OH increased by 46.4 ± 12.2{\%} in response to preindustrial to present-day anthropogenic NOx emission increases, and decreased by 17.3 ± 2.3{\%}, 7.6 ± 1.5{\%}, and 3.1 ± 3.0{\%} due to methane burden, and anthropogenic CO, and NMVOC emissions increases, respectively.},
author = {Naik, V. and Voulgarakis, A. and Fiore, A. M. and Horowitz, L. W. and Lamarque, J.-F. and Lin, M. and Prather, M. J. and Young, P. J. and Bergmann, D. and Cameron-Smith, P. J. and Cionni, I. and Collins, W. J. and Dals{\o}ren, S. B. and Doherty, R. and Eyring, V. and Faluvegi, G. and Folberth, G. A. and Josse, B. and Lee, Y. H. and MacKenzie, I. A. and Nagashima, T. and van Noije, T. P. C. and Plummer, D. A. and Righi, M. and Rumbold, S. T. and Skeie, R. and Shindell, D. T. and Stevenson, D. S. and Strode, S. and Sudo, K. and Szopa, S. and Zeng, G.},
doi = {10.5194/acp-13-5277-2013},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {may},
number = {10},
pages = {5277--5298},
title = {{Preindustrial to present-day changes in tropospheric hydroxyl radical and methane lifetime from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)}},
url = {https://acp.copernicus.org/articles/13/5277/2013/},
volume = {13},
year = {2013}
}
@article{Nakano2015,
abstract = {Abstract Using an ocean carbon cycle model embedded in an ocean general circulation model, we examine how the budget of anthropogenic CO2 (Cant) is controlled by ocean dynamics. To complement recent studies showing only vertically integrated budgets, we provide a step-by-step description by making use of three different coarse grainings of the full vertical resolution of the ocean model in our budget analysis. For the 11 subdomains of the global ocean, these coarse grainings are (1) a one-layer (vertically integrated) budget, (2) a three-layer budget, and (3) an 11-layer budget. We largely focus on the Pacific circulation. We identify and quantify substantial carbon transport associated with the subtropical cells (STCs), which are dominant contributors to the meridional overturning circulation in the upper ocean in the tropics and subtropics, as playing a fundamental role in governing the ocean interior distribution of Cant. The upper branch of the STCs transports Cant-rich water from the tropics to the subtropics, contributing to the precondition for the high Cant inventory in mode waters. The lower branch of the STCs carries about two thirds of the transported Cant back to the tropics, while it largely excludes Subtropical Mode Waters. This work implies that the reemergence of Cant through recirculation within the STCs may lead to a reduced capacity for further Cant uptake via gas exchange into the surface ocean, potentially contributing to a positive carbon-climate feedback.},
annote = {doi: 10.1002/2015GB005128},
author = {Nakano, H and Ishii, M and Rodgers, K B and Tsujino, H and Yamanaka, G},
doi = {10.1002/2015GB005128},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {OGCM,anthropogenic CO2,transport},
month = {oct},
number = {10},
pages = {1706--1724},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Anthropogenic CO2 uptake, transport, storage, and dynamical controls in the ocean imposed by the meridional overturning circulation: A modeling study}},
url = {https://doi.org/10.1002/2015GB005128 http://doi.wiley.com/10.1002/2015GB005128},
volume = {29},
year = {2015}
}
@article{Nakazawa1997,
author = {Nakazawa, Takakiyo and Morimoto, Shinji and Aoki, Shuhji and Tanaka, Masayuki},
doi = {10.1029/96JD02720},
issn = {01480227},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jan},
number = {D1},
pages = {1271--1285},
title = {{Temporal and spatial variations of the carbon isotopic ratio of atmospheric carbon dioxide in the western Pacific region}},
url = {http://doi.wiley.com/10.1029/96JD02720},
volume = {102},
year = {1997}
}
@article{Naqvi2010,
abstract = {Abstract. We review here the available information on methane (CH4) and nitrous oxide (N2O) from major marine, mostly coastal, oxygen (O2)-deficient zones formed both naturally and as a result of human activities (mainly eutrophication). Concentrations of both gases in subsurface waters are affected by ambient O2 levels to varying degrees. Organic matter supply to seafloor appears to be the primary factor controlling CH4 production in sediments and its supply to (and concentration in) overlying waters, with bottom-water O2-deficiency exerting only a modulating effect. High (micromolar level) CH4 accumulation occurs in anoxic (sulphidic) waters of silled basins, such as the Black Sea and Cariaco Basin, and over the highly productive Namibian shelf. In other regions experiencing various degrees of O2-deficiency (hypoxia to anoxia), CH4 concentrations vary from a few to hundreds of nanomolar levels. Since coastal O2-deficient zones are generally very productive and are sometimes located close to river mouths and submarine hydrocarbon seeps, it is difficult to differentiate any O2-deficiency-induced enhancement from in situ production of CH4 in the water column and its inputs through freshwater runoff or seepage from sediments. While the role of bottom-water O2-deficiency in CH4 formation appears to be secondary, even when CH4 accumulates in O2-deficient subsurface waters, methanotrophic activity severely restricts its diffusive efflux to the atmosphere. As a result, an intensification or expansion of coastal O2-deficient zones will probably not drastically change the present status where emission from the ocean as a whole forms an insignificant term in the atmospheric CH4 budget. The situation is different for N2O, the production of which is greatly enhanced in low-O2 waters, and although it is lost through denitrification in most suboxic and anoxic environments, the peripheries of such environments offer most suitable conditions for its production, with the exception of enclosed anoxic basins. Most O2-deficient systems serve as strong net sources of N2O to the atmosphere. This is especially true for coastal upwelling regions with shallow O2-deficient zones where a dramatic increase in N2O production often occurs in rapidly denitrifying waters. Nitrous oxide emissions from these zones are globally significant, and so their ongoing intensification and expansion is likely to lead to a significant increase in N2O emission from the ocean. However, a meaningful quantitative prediction of this increase is not possible at present because of continuing uncertainties concerning the formative pathways to N2O as well as insufficient data from key coastal regions.},
author = {Naqvi, S. W. A. and Bange, H. W. and Far{\'{i}}as, L. and Monteiro, P. M. S. and Scranton, M. I. and Zhang, J},
doi = {10.5194/bg-7-2159-2010},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jul},
number = {7},
pages = {2159--2190},
publisher = {Copernicus Publications (EGU)},
title = {{Marine hypoxia/anoxia as a source of CH4 and N2O}},
url = {https://bg.copernicus.org/articles/7/2159/2010/},
volume = {7},
year = {2010}
}
@techreport{NationalAcademiesofSciencesandMedicine2019,
abstract = {To achieve goals for climate and economic growth, “negative emissions technologies” (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions. In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and “sustainable scale potential” for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact.},
address = {Washington, DC, USA},
author = {NASEM},
doi = {10.17226/25259},
isbn = {978-0-309-48452-7},
keywords = {Earth Sciences,Environment and Environmental Studies},
language = {English},
month = {mar},
pages = {510},
publisher = {National Academies of Sciences, Engineering, and Medicine (NASEM). The National Academies Press},
title = {{Negative Emissions Technologies and Reliable Sequestration: A Research Agenda}},
url = {https://www.nap.edu/catalog/25259/negative-emissions-technologies-and-reliable-sequestration-a-research-agenda https://www.nap.edu/catalog/25259},
year = {2019}
}
@article{Natali2019,
abstract = {Recent warming in the Arctic, which has been amplified during the winter1–3, greatly enhances microbial decomposition of soil organic matter and subsequent release of carbon dioxide (CO2)4. However, the amount of CO2 released in winter is not known and has not been well represented by ecosystem models or empirically based estimates5,6. Here we synthesize regional in situ observations of CO2 flux from Arctic and boreal soils to assess current and future winter carbon losses from the northern permafrost domain. We estimate a contemporary loss of 1,662 TgC per year from the permafrost region during the winter season (October–April). This loss is greater than the average growing season carbon uptake for this region estimated from process models (−1,032 TgC per year). Extending model predictions to warmer conditions up to 2100 indicates that winter CO2 emissions will increase 17{\%} under a moderate mitigation scenario—Representative Concentration Pathway 4.5—and 41{\%} under business-as-usual emissions scenario—Representative Concentration Pathway 8.5. Our results provide a baseline for winter CO2 emissions from northern terrestrial regions and indicate that enhanced soil CO2 loss due to winter warming may offset growing season carbon uptake under future climatic conditions.},
author = {Natali, Susan M and Watts, Jennifer D and Rogers, Brendan M and Potter, Stefano and Ludwig, Sarah M and Selbmann, Anne-Katrin and Sullivan, Patrick F and Abbott, Benjamin W and Arndt, Kyle A and Birch, Leah and Bj{\"{o}}rkman, Mats P and Bloom, A Anthony and Celis, Gerardo and Christensen, Torben R and Christiansen, Casper T and Commane, Roisin and Cooper, Elisabeth J and Crill, Patrick and Czimczik, Claudia and Davydov, Sergey and Du, Jinyang and Egan, Jocelyn E and Elberling, Bo and Euskirchen, Eugenie S and Friborg, Thomas and Genet, H{\'{e}}l{\`{e}}ne and G{\"{o}}ckede, Mathias and Goodrich, Jordan P and Grogan, Paul and Helbig, Manuel and Jafarov, Elchin E and Jastrow, Julie D and Kalhori, Aram A M and Kim, Yongwon and Kimball, John S and Kutzbach, Lars and Lara, Mark J and Larsen, Klaus S and Lee, Bang-Yong and Liu, Zhihua and Loranty, Michael M and Lund, Magnus and Lupascu, Massimo and Madani, Nima and Malhotra, Avni and Matamala, Roser and McFarland, Jack and McGuire, A David and Michelsen, Anders and Minions, Christina and Oechel, Walter C and Olefeldt, David and Parmentier, Frans-Jan W and Pirk, Norbert and Poulter, Ben and Quinton, William and Rezanezhad, Fereidoun and Risk, David and Sachs, Torsten and Schaefer, Kevin and Schmidt, Niels M and Schuur, Edward A G and Semenchuk, Philipp R and Shaver, Gaius and Sonnentag, Oliver and Starr, Gregory and Treat, Claire C and Waldrop, Mark P and Wang, Yihui and Welker, Jeffrey and Wille, Christian and Xu, Xiaofeng and Zhang, Zhen and Zhuang, Qianlai and Zona, Donatella},
doi = {10.1038/s41558-019-0592-8},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {11},
pages = {852--857},
title = {{Large loss of CO2 in winter observed across the northern permafrost region}},
url = {https://doi.org/10.1038/s41558-019-0592-8},
volume = {9},
year = {2019}
}
@article{Natchimuthu2017,
author = {Natchimuthu, Sivakiruthika and Wallin, Marcus B and Klemedtsson, Leif and Bastviken, David},
doi = {10.1038/srep39729},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {39729},
publisher = {The Author(s)},
title = {{Spatio-temporal patterns of stream methane and carbon dioxide emissions in a hemiboreal catchment in Southwest Sweden}},
url = {http://dx.doi.org/10.1038/srep39729 http://10.0.4.14/srep39729 https://www.nature.com/articles/srep39729{\#}supplementary-information http://www.nature.com/articles/srep39729},
volume = {7},
year = {2017}
}
@article{Negrete-Garcia2019,
abstract = {Models project that with current CO2 emission rates, the Southern Ocean surface will be undersaturated with respect to aragonite by the end of this century1–4. This will result in widespread impacts on biogeochemistry and ocean ecosystems5–7, particularly the health of aragonitic organisms, such as pteropods7, which can dominate polar surface water communities6. Here, we quantify the depth of the present-day Southern Ocean aragonite saturation horizon using hydrographic and ocean carbon chemistry observations, and use a large ensemble of simulations from the Community Earth System Model (CESM)8,9 to track its evolution. A new, shallow aragonite saturation horizon emerges in many Southern Ocean locations between now and the end of the century. While all ensemble members capture the emergence, internal climate variability may affect the year of emergence; thus, its detection may have been overlooked by ensemble average analysis in the past. The emergence of the new horizon is driven by the slow accumulation of anthropogenic CO2 in the Southern Ocean thermocline, where the carbonate ion concentration exhibits a local minimum and approaches undersaturation. The new horizon is also apparent under an emission-stabilizing scenario indicating an inevitable, sudden decrease in the volume of suitable habitat for aragonitic organisms.},
author = {Negrete-Garc{\'{i}}a, Gabriela and Lovenduski, Nicole S and Hauri, Claudine and Krumhardt, Kristen M and Lauvset, Siv K},
doi = {10.1038/s41558-019-0418-8},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {apr},
number = {4},
pages = {313--317},
title = {{Sudden emergence of a shallow aragonite saturation horizon in the Southern Ocean}},
url = {https://doi.org/10.1038/s41558-019-0418-8 http://www.nature.com/articles/s41558-019-0418-8},
volume = {9},
year = {2019}
}
@article{Nehrbass-Ahles2020,
abstract = {Pulse-like carbon dioxide release to the atmosphere on centennial time scales has only been identified for the most recent glacial and deglacial periods and is thought to be absent during warmer climate conditions. Here, we present a high-resolution carbon dioxide record from 330,000 to 450,000 years before present, revealing pronounced carbon dioxide jumps (CDJ) under cold and warm climate conditions. CDJ come in two varieties that we attribute to invigoration or weakening of the Atlantic meridional overturning circulation (AMOC) and associated northward and southward shifts of the intertropical convergence zone, respectively. We find that CDJ are pervasive features of the carbon cycle that can occur during interglacial climate conditions if land ice masses are sufficiently extended to be able to disturb the AMOC by freshwater input.},
author = {Nehrbass-Ahles, C. and Shin, J. and Schmitt, J. and Bereiter, B. and Joos, F. and Schilt, A. and Schmidely, L. and Silva, L. and Teste, G. and Grilli, R. and Chappellaz, J. and Hodell, D. and Fischer, H. and Stocker, T. F.},
doi = {10.1126/science.aay8178},
issn = {10959203},
journal = {Science},
number = {6506},
pages = {1000--1005},
pmid = {32820127},
title = {{Abrupt CO2 release to the atmosphere under glacia and early interglacial climate conditions}},
volume = {369},
year = {2020}
}
@article{Nevison2004,
abstract = {A continuous record of atmospheric N2O measured from a tower in northern California captures strong pulses of N2O released by coastal upwelling events. The atmospheric record offers a unique, observation‐based method for quantifying the coastal N2O source. A coastal upwelling model is developed and compared to the constraints imposed by the atmospheric record in the Pacific Northwest coastal region. The upwelling model is based on Ekman theory and driven by high‐resolution wind and SST data and by relationships between subsurface N2O and temperature. A simplified version of the upwelling model is extended to the world's major eastern boundary regions to estimate a total coastal upwelling source of ∼0.2 ± {\textgreater}70{\%} Tg N2O‐N/yr. This flux represents ∼5{\%} of the total ocean source, estimated here at ∼4 Tg N2O‐N/yr using traditional gas‐transfer methods, and is probably largely neglected in current N2O budgets.},
author = {Nevison, Cynthia D and Lueker, Timothy J. and Weiss, Ray F},
doi = {10.1029/2003GB002110},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {mar},
number = {1},
pages = {GB1018},
title = {{Quantifying the nitrous oxide source from coastal upwelling}},
url = {http://doi.wiley.com/10.1029/2003GB002110},
volume = {18},
year = {2004}
}
@article{Nevison2020,
abstract = {The Southern Annular Mode (SAM) is the dominant mode of climate variability in the Southern Ocean, but only a few observational studies have linked variability in SAM to changes in ocean circulation. Atmospheric potential oxygen (APO) combines atmospheric O2/N2 and CO2 data to mask the influence of terrestrial exchanges, yielding a tracer that is sensitive mainly to ocean circulation and biogeochemistry. We show that observed wintertime anomalies of APO are significantly correlated to SAM in 25- to 30-year time series at three Southern Hemisphere sites, while CO2 anomalies are also weakly correlated. We find additional correlations between SAM and O2 air-sea fluxes in austral winter inferred from both an atmospheric inversion of observed APO and a forced ocean biogeochemistry model simulation. The model results indicate that the correlation with SAM is mechanistically linked to stronger wind speeds and upwelling, which brings oxygen-depleted deep waters to the surface.},
author = {Nevison, Cynthia D. and Munro, David R. and Lovenduski, Nicole S. and Keeling, Ralph F. and Manizza, Manfredi and Morgan, Eric J. and R{\"{o}}denbeck, Christian},
doi = {10.1029/2019GL085667},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Antarctic oscillation,Southern Annular Mode,air-sea flux,atmospheric potential oxygen,carbon dioxide,seasonal cycles},
month = {feb},
number = {4},
pages = {e2019GL085667},
publisher = {Blackwell Publishing Ltd},
title = {{Southern Annular Mode Influence on Wintertime Ventilation of the Southern Ocean Detected in Atmospheric O2 and CO2 Measurements}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2019GL085667},
volume = {47},
year = {2020}
}
@article{Ni2018,
abstract = {Atmospheric methane (CH4) concentration has been increasing rapidly over recent decades. Forest soils are a major sink for atmospheric CH4, but evidence from long-term in situ observation is limited, so little is known about how the soil CH4 sink responds to changing environmental conditions. We measured soil to atmosphere net CH4 fluxes at long-term ecological research sites in Baltimore, Maryland (1998{\{}$\backslash$textendash{\}}2016) and Hubbard Brook, New Hampshire (2002{\{}$\backslash$textendash{\}}2015) and found significant decreases in CH4 uptake at both sites. Moreover, a literature review showed that CH4 uptake in forest soils around the world is also declining, especially forests from 0{\{}$\backslash$textendash{\}}60 {\{}$\backslash$textdegree{\}}N latitude, where precipitation has been increasing. We conclude that the current soil CH4 sink may be overestimated over large regional areas.Forest soils are a sink for atmospheric methane (CH4) and play an important role in modulating the global CH4 budget. However, whether CH4 uptake by forest soils is affected by global environmental change is unknown. We measured soil to atmosphere net CH4 fluxes in temperate forests at two long-term ecological research sites in the northeastern United States from the late 1990s to the mid-2010s. We found that annual soil CH4 uptake decreased by 62{\%} and 53{\%} in urban and rural forests in Baltimore, Maryland and by 74{\%} and 89{\%} in calcium-fertilized and reference forests at Hubbard Brook, New Hampshire over this period. This decrease occurred despite marked declines in nitrogen deposition and increases in atmospheric CH4 concentration and temperature, which should lead to increases in CH4 uptake. This decrease in soil CH4 uptake appears to be driven by increases in precipitation and soil hydrological flux. Furthermore, an analysis of CH4 uptake around the globe showed that CH4 uptake in forest soils has decreased by an average of 77{\%} from 1988 to 2015, particularly in forests located from 0 to 60 {\{}$\backslash$textdegree{\}}N latitude where precipitation has been increasing. We conclude that the soil CH4 sink may be declining and overestimated in several regions across the globe.},
author = {Ni, Xiangyin and Groffman, Peter M},
doi = {10.1073/pnas.1807377115},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {aug},
number = {34},
pages = {8587--8590},
publisher = {National Academy of Sciences},
title = {{Declines in methane uptake in forest soils}},
url = {http://www.pnas.org/content/early/2018/07/31/1807377115 http://www.pnas.org/lookup/doi/10.1073/pnas.1807377115},
volume = {115},
year = {2018}
}
@article{Nicely2018,
abstract = {Abstract The oxidizing capacity of the troposphere is controlled primarily by the abundance of hydroxyl radical (OH). The global mean concentration of tropospheric OH, [OH]TROP (the burden of OH in the global troposphere appropriate for calculating the lifetime of methane) inferred from measurements of methyl chloroform has remained relatively constant during the past several decades despite rising levels of methane that should have led to a decline. Here we examine other factors that may have affected [OH]TROP such as the changing values of stratospheric ozone, rising tropospheric H2O, varying burden of NOx (=NO+NO2), rising temperatures, and widening of the climatological tropics due to expansion of the Hadley cell. Our analysis suggests the positive trends in [OH]TROP due to H2O, NOx, and overhead O3, and tropical expansion are large enough (? [OH]TROP = +0.95 ± 0.18{\%}/decade) to counter almost all of the expected decrease in [OH]TROP due to rising methane (? [OH]TROP = ?1.01 ± 0.05{\%}/decade) over the period 1980 to 2015, while variations in temperature contribute almost no trend (? [OH]TROP = ?0.02 ± 0.02{\%}/decade) in [OH]TROP. The approximated impact of Hadley cell expansion on [OH]TROP is also a small but not insignificant factor partially responsible for the steadiness of tropospheric oxidizing capacity over the past several decades, which free-running models likely do not capture.},
author = {Nicely, Julie M and Canty, Timothy P and Manyin, Michael and Oman, Luke D and Salawitch, Ross J and Steenrod, Stephen D and Strahan, Susan E and Strode, Sarah A},
doi = {10.1029/2018JD028388},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {sep},
number = {18},
pages = {10774--10795},
title = {{Changes in global tropospheric OH expected as a result of climate change over the last several decades}},
url = {http://doi.wiley.com/10.1029/2018JD028388},
volume = {123},
year = {2018}
}
@article{Nicholls,
abstract = {To determine the remaining carbon budget, a new framework was introduced in the Intergovernmental Panel on Climate Change's Special Report on Global Warming of 1.5 °C (SR1.5). We refer to this as a 'segmented' framework because it considers the various components of the carbon budget derivation independently from one another. Whilst implementing this segmented framework, in SR1.5 the assumption was that there is a strictly linear relationship between cumulative CO2 emissions and CO2-induced warming i.e. the TCRE is constant and can be applied to a range of emissions scenarios. Here we test whether such an approach is able to replicate results from model simulations that take the climate system's internal feedbacks and non-linearities into account. Within our modelling framework, following the SR1.5's choices leads to smaller carbon budgets than using simulations with interacting climate components. For 1.5 °C and 2 °C warming targets, the differences are 50 GtCO2 (or 10{\%}) and 260 GtCO2 (or 17{\%}), respectively. However, by relaxing the assumption of strict linearity, we find that this difference can be reduced to around 0 GtCO2 for 1.5 °C of warming and 80 GtCO2 (or 5{\%}) for 2.0 °C of warming (for middle of the range estimates of the carbon cycle and warming response to anthropogenic emissions). We propose an updated implementation of the segmented framework that allows for the consideration of non-linearities between cumulative CO2 emissions and CO2-induced warming.},
author = {Nicholls, Zebedee R. J. and Gieseke, R. and Lewis, Jared and Nauels, Alexander and Meinshausen, Malte},
doi = {10.1088/1748-9326/ab83af},
journal = {Environmental Research Letters},
number = {7},
pages = {074017},
title = {{Implications of non-linearities between cumulative CO2 emissions and CO2-induced warming for assessing the remaining carbon budget}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/ab83af},
volume = {15},
year = {2020}
}
@article{Nichols2019,
author = {Nichols, Jonathan E. and Peteet, Dorothy M.},
doi = {10.1038/s41561-019-0454-z},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {nov},
number = {11},
pages = {917--921},
title = {{Rapid expansion of northern peatlands and doubled estimate of carbon storage}},
url = {http://www.nature.com/articles/s41561-019-0454-z},
volume = {12},
year = {2019}
}
@article{Nie2013,
abstract = {Aim: Plant root traits regulate belowground C inputs, soil nutrient and water uptake, and play critical roles in determining sustainable plant production and consequences for ecosystem C storage. However, the effects of elevated CO2 on root morphology and function have not been well quantified. We reveal general patterns of root trait responses to elevated CO2 from field manipulative experiments. Location: North America, Europe, Oceania, Asia. Methods: The meta-analysis approach was used to examine the effects of CO2 elevation on 17 variables associated with root morphology, biomass size and distribution, C and N concentrations and pools, turnover and fungal colonization from 110 published studies. Results: Elevated CO2 increased root length (+26.0{\%}) and diameter (+8.4{\%}). Elevated CO2 also stimulated total root (+28.8{\%}), fine root (+27.7{\%}) and coarse root biomass (+25.3{\%}), demonstrating strong responses of root morphology and biomass. Elevated CO2 increased the root:shoot ratio (+8.5{\%}) and decreased the proportion of roots in the topsoil (-8.4{\%}), suggesting that plants expand rooting systems. In addition, elevated CO2 decreased N concentration (-7.1{\%}), but did not affect C concentration, and thus increased the C:N ratio (+7.8{\%}). Root C (+29.3{\%}) increased disproportionately relative to root N pools (+9.4{\%}) under elevated CO2. Functional traits were also strongly affected by elevated CO2, which increased respiration (+58.9{\%}), rhizodeposition (+37.9{\%}) and fungal colonization (+3.3{\%}). Main conclusions: These results suggest that elevated CO2 promoted root morphological development, root system expansion and C input to soils, implying that the sensitive responses of root morphology and function to elevated CO2 would increase long-term belowground C sequestration. {\textcopyright} 2013 John Wiley {\&} Sons Ltd.},
author = {Nie, Ming and Lu, Meng and Bell, Jennifer and Raut, Swastika and Pendall, Elise},
doi = {10.1111/geb.12062},
issn = {1466822X},
journal = {Global Ecology and Biogeography},
keywords = {C sequestration,CO2,Free-air CO2 enrichment,Meta-analysis,Open top chamber,Plant root},
number = {10},
pages = {1095--1105},
title = {{Altered root traits due to elevated CO2: A meta-analysis}},
volume = {22},
year = {2013}
}
@article{doi:10.1002/2016GB005406,
abstract = {Abstract From 2007 to 2013, the globally averaged mole fraction of methane in the atmosphere increased by 5.7 ± 1.2 ppb yr−1. Simultaneously, $\delta$13CCH4 (a measure of the 13C/12C isotope ratio in methane) has shifted to significantly more negative values since 2007. Growth was extreme in 2014, at 12.5 ± 0.4 ppb, with a further shift to more negative values being observed at most latitudes. The isotopic evidence presented here suggests that the methane rise was dominated by significant increases in biogenic methane emissions, particularly in the tropics, for example, from expansion of tropical wetlands in years with strongly positive rainfall anomalies or emissions from increased agricultural sources such as ruminants and rice paddies. Changes in the removal rate of methane by the OH radical have not been seen in other tracers of atmospheric chemistry and do not appear to explain short-term variations in methane. Fossil fuel emissions may also have grown, but the sustained shift to more 13C-depleted values and its significant interannual variability, and the tropical and Southern Hemisphere loci of post-2007 growth, both indicate that fossil fuel emissions have not been the dominant factor driving the increase. A major cause of increased tropical wetland and tropical agricultural methane emissions, the likely major contributors to growth, may be their responses to meteorological change.},
author = {Nisbet, E G and Dlugokencky, E J and Manning, M. R. and Lowry, D and Fisher, R E and France, J L and Michel, S E and Miller, J B and White, J W C and Vaughn, B and Bousquet, P and Pyle, J A and Warwick, N J and Cain, M and Brownlow, R and Zazzeri, G and Lanoisell{\'{e}}, M and Manning, A C and Gloor, E and Worthy, D E J and Brunke, E.-G. and Labuschagne, C and Wolff, E W and Ganesan, A L},
doi = {10.1002/2016GB005406},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {atmospheric methane,growth,isotopic measurement},
month = {sep},
number = {9},
pages = {1356--1370},
title = {{Rising atmospheric methane: 2007–2014 growth and isotopic shift}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016GB005406 http://doi.wiley.com/10.1002/2016GB005406},
volume = {30},
year = {2016}
}
@article{Nisbet2019b,
author = {Nisbet, E. G. and Manning, M. R. and Dlugokencky, E. J. and Fisher, R. E. and Lowry, D. and Michel, S. E. and Myhre, C. Lund and Platt, S. M. and Allen, G. and Bousquet, P. and Brownlow, R. and Cain, M. and France, J. L. and Hermansen, O. and Hossaini, R. and Jones, A. E. and Levin, I. and Manning, A. C. and Myhre, G. and Pyle, J. A. and Vaughn, B. H. and Warwick, N. J. and White, J. W. C.},
doi = {10.1029/2018GB006009},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {10.1029/2018GB006009 and atmospheric methane,OH destruction of methane,Paris Agreement,fossil fuel methane emissions,methane isotopes,wetland methane emissions},
month = {mar},
pages = {2018GB006009},
title = {{Very strong atmospheric methane growth in the 4 years 2014–2017: implications for the Paris Agreement}},
url = {https://doi.org/10.1029/2018GB006009 https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GB006009},
volume = {33},
year = {2019}
}
@article{Nisbet2020a,
abstract = {Abstract The atmospheric methane burden is increasing rapidly, contrary to pathways compatible with the goals of the 2015 United Nations Framework Convention on Climate Change Paris Agreement. Urgent action is required to bring methane back to a pathway more in line with the Paris goals. Emission reduction from “tractable” (easier to mitigate) anthropogenic sources such as the fossil fuel industries and landfills is being much facilitated by technical advances in the past decade, which have radically improved our ability to locate, identify, quantify, and reduce emissions. Measures to reduce emissions from “intractable” (harder to mitigate) anthropogenic sources such as agriculture and biomass burning have received less attention and are also becoming more feasible, including removal from elevated-methane ambient air near to sources. The wider effort to use microbiological and dietary intervention to reduce emissions from cattle (and humans) is not addressed in detail in this essentially geophysical review. Though they cannot replace the need to reach “net-zero” emissions of CO2, significant reductions in the methane burden will ease the timescales needed to reach required CO2 reduction targets for any particular future temperature limit. There is no single magic bullet, but implementation of a wide array of mitigation and emission reduction strategies could substantially cut the global methane burden, at a cost that is relatively low compared to the parallel and necessary measures to reduce CO2, and thereby reduce the atmospheric methane burden back toward pathways consistent with the goals of the Paris Agreement.},
author = {Nisbet, E G and Fisher, R E and Lowry, D and France, J L and Allen, G and Bakkaloglu, S and Broderick, T J and Cain, M and Coleman, M and Fernandez, J and Forster, G and Griffiths, P T and Iverach, C P and Kelly, B F J and Manning, M R and Nisbet-Jones, P B R and Pyle, J A and Townsend-Small, A and Al-Shalaan, A and Warwick, N and Zazzeri, G},
doi = {https://doi.org/10.1029/2019RG000675},
journal = {Reviews of Geophysics},
number = {1},
pages = {e2019RG000675},
title = {{Methane Mitigation: Methods to Reduce Emissions, on the Path to the Paris Agreement}},
volume = {58},
year = {2020}
}
@article{Nobre10759,
abstract = {The Amazonian tropical forests have been disappearing at a fast rate in the last 50 y due to deforestation to open areas for agriculture, posing high risks of irreversible changes to biodiversity and ecosystems. Climate change poses additional risks to the stability of the forests. Studies suggest {\{}$\backslash$textquotedblleft{\}}tipping points{\{}$\backslash$textquotedblright{\}} not to be transgressed: 4{\{}$\backslash$textdegree{\}} C of global warming or 40{\%} of total deforested area. The regional development debate has focused on attempting to reconcile maximizing conservation with intensification of traditional agriculture. Large reductions of deforestation in the last decade open up opportunities for an alternative model based on seeing the Amazon as a global public good of biological assets for the creation of high-value products and ecosystem services.For half a century, the process of economic integration of the Amazon has been based on intensive use of renewable and nonrenewable natural resources, which has brought significant basin-wide environmental alterations. The rural development in the Amazonia pushed the agricultural frontier swiftly, resulting in widespread land-cover change, but agriculture in the Amazon has been of low productivity and unsustainable. The loss of biodiversity and continued deforestation will lead to high risks of irreversible change of its tropical forests. It has been established by modeling studies that the Amazon may have two {\{}$\backslash$textquotedblleft{\}}tipping points,{\{}$\backslash$textquotedblright{\}} namely, temperature increase of 4 {\{}$\backslash$textdegree{\}}C or deforestation exceeding 40{\%} of the forest area. If transgressed, large-scale {\{}$\backslash$textquotedblleft{\}}savannization{\{}$\backslash$textquotedblright{\}} of mostly southern and eastern Amazon may take place. The region has warmed about 1 {\{}$\backslash$textdegree{\}}C over the last 60 y, and total deforestation is reaching 20{\%} of the forested area. The recent significant reductions in deforestation{\{}$\backslash$textemdash{\}}80{\%} reduction in the Brazilian Amazon in the last decade{\{}$\backslash$textemdash{\}}opens up opportunities for a novel sustainable development paradigm for the future of the Amazon. We argue for a new development paradigm{\{}$\backslash$textemdash{\}}away from only attempting to reconcile maximizing conservation versus intensification of traditional agriculture and expansion of hydropower capacity{\{}$\backslash$textemdash{\}}in which we research, develop, and scale a high-tech innovation approach that sees the Amazon as a global public good of biological assets that can enable the creation of innovative high-value products, services, and platforms through combining advanced digital, biological, and material technologies of the Fourth Industrial Revolution in progress.},
author = {Nobre, Carlos A and Sampaio, Gilvan and Borma, Laura S and Castilla-Rubio, Juan Carlos and Silva, Jos{\'{e}} S and Cardoso, Manoel},
doi = {10.1073/pnas.1605516113},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {39},
pages = {10759--10768},
publisher = {National Academy of Sciences},
title = {{Land-use and climate change risks in the Amazon and the need of a novel sustainable development paradigm}},
url = {https://www.pnas.org/content/113/39/10759},
volume = {113},
year = {2016}
}
@article{doi:10.1146/annurev-ecolsys-102209-144647,
abstract = {Free-air CO2 enrichment (FACE) experiments have provided novel insights into the ecological mechanisms controlling the cycling and storage of carbon in terrestrial ecosystems and contribute to our ability to project how ecosystems respond to increasing CO2 in the Earth's atmosphere. Important lessons emerge by evaluating a set of hypotheses that initially guided the design and longevity of forested FACE experiments. Net primary productivity is increased by elevated CO2, but the response can diminish over time. Carbon accumulation is driven by the distribution of carbon among plant and soil components with differing turnover rates and by interactions between the carbon and nitrogen cycles. Plant community structure may change, but elevated CO2 has only minor effects on microbial community structure. FACE results provide a strong foundation for next-generation experiments in unexplored ecosystems and inform coupled climate-biogeochemical models of the ecological mechanisms controlling ecosystem response to the rising atmospheric CO2 concentration.},
author = {Norby, Richard J and Zak, Donald R},
doi = {10.1146/annurev-ecolsys-102209-144647},
issn = {1543-592X},
journal = {Annual Review of Ecology, Evolution, and Systematics},
month = {dec},
number = {1},
pages = {181--203},
title = {{Ecological Lessons from Free-Air CO2 Enrichment (FACE) Experiments}},
url = {https://doi.org/10.1146/annurev-ecolsys-102209-144647 http://www.annualreviews.org/doi/10.1146/annurev-ecolsys-102209-144647},
volume = {42},
year = {2011}
}
@article{Norby2010,
abstract = {Stimulation of terrestrial plant production by rising CO(2) concentration is projected to reduce the airborne fraction of anthropogenic CO(2) emissions. Coupled climate-carbon cycle models are sensitive to this negative feedback on atmospheric CO(2), but model projections are uncertain because of the expectation that feedbacks through the nitrogen (N) cycle will reduce this so-called CO(2) fertilization effect. We assessed whether N limitation caused a reduced stimulation of net primary productivity (NPP) by elevated atmospheric CO(2) concentration over 11 y in a free-air CO(2) enrichment (FACE) experiment in a deciduous Liquidambar styraciflua (sweetgum) forest stand in Tennessee. During the first 6 y of the experiment, NPP was significantly enhanced in forest plots exposed to 550 ppm CO(2) compared with NPP in plots in current ambient CO(2), and this was a consistent and sustained response. However, the enhancement of NPP under elevated CO(2) declined from 24{\%} in 2001-2003 to 9{\%} in 2008. Global analyses that assume a sustained CO(2) fertilization effect are no longer supported by this FACE experiment. N budget analysis supports the premise that N availability was limiting to tree growth and declining over time--an expected consequence of stand development, which was exacerbated by elevated CO(2). Leaf- and stand-level observations provide mechanistic evidence that declining N availability constrained the tree response to elevated CO(2); these observations are consistent with stand-level model projections. This FACE experiment provides strong rationale and process understanding for incorporating N limitation and N feedback effects in ecosystem and global models used in climate change assessments.},
archivePrefix = {arXiv},
arxivId = {arXiv:1604.05974v2},
author = {Norby, R. J. and Warren, J. M. and Iversen, C. M. and Medlyn, B. E. and McMurtrie, R. E.},
doi = {10.1073/pnas.1006463107},
eprint = {arXiv:1604.05974v2},
isbn = {0027-8424},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {nov},
number = {45},
pages = {19368--19373},
pmid = {20974944},
title = {{CO2 enhancement of forest productivity constrained by limited nitrogen availability}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1006463107},
volume = {107},
year = {2010}
}
@article{Norby2016,
author = {Norby, Richard J. and {De Kauwe}, Martin G. and Domingues, Tomas F. and Duursma, Remko A. and Ellsworth, David S. and Goll, Daniel S. and Lapola, David M. and Luus, Kristina A. and MacKenzie, A. Rob and Medlyn, Belinda E. and Pavlick, Ryan and Rammig, Anja and Smith, Benjamin and Thomas, Rick and Thonicke, Kirsten and Walker, Anthony P. and Yang, Xiaojuan and Zaehle, S{\"{o}}nke},
doi = {10.1111/nph.13593},
issn = {0028646X},
journal = {New Phytologist},
month = {jan},
number = {1},
pages = {17--28},
title = {{Model–data synthesis for the next generation of forest free-air CO2 enrichment (FACE) experiments}},
url = {http://doi.wiley.com/10.1111/nph.13593},
volume = {209},
year = {2016}
}
@article{Nottingham2020,
abstract = {Tropical soils contain one-third of the carbon stored in soils globally1, so destabilization of soil organic matter caused by the warming predicted for tropical regions this century2 could accelerate climate change by releasing additional carbon dioxide (CO2) to the atmosphere3–6. Theory predicts that warming should cause only modest carbon loss from tropical soils relative to those at higher latitudes5,7, but there have been no warming experiments in tropical forests to test this8. Here we show that in situ experimental warming of a lowland tropical forest soil on Barro Colorado Island, Panama, caused an unexpectedly large increase in soil CO2 emissions. Two years of warming of the whole soil profile by four degrees Celsius increased CO2 emissions by 55 per cent compared to soils at ambient temperature. The additional CO2 originated from heterotrophic rather than autotrophic sources, and equated to a loss of 8.2 ± 4.2 (one standard error) tonnes of carbon per hectare per year from the breakdown of soil organic matter. During this time, we detected no acclimation of respiration rates, no thermal compensation or change in the temperature sensitivity of enzyme activities, and no change in microbial carbon-use efficiency. These results demonstrate that soil carbon in tropical forests is highly sensitive to warming, creating a potentially substantial positive feedback to climate change.},
author = {Nottingham, Andrew T and Meir, Patrick and Velasquez, Esther and Turner, Benjamin L},
doi = {10.1038/s41586-020-2566-4},
issn = {1476-4687},
journal = {Nature},
number = {7820},
pages = {234--237},
title = {{Soil carbon loss by experimental warming in a tropical forest}},
url = {https://doi.org/10.1038/s41586-020-2566-4},
volume = {584},
year = {2020}
}
@article{Novick2016,
abstract = {We merge concepts from stomatal optimization theory and cohesion-tension theory to examine the dynamics of three mechanisms that are potentially limiting to leaf-level gas exchange in trees during drought: (1) a 'demand limitation' driven by an assumption of optimal stomatal functioning; (2) 'hydraulic limitation' of water movement from the roots to the leaves; and (3) 'non-stomatal' limitations imposed by declining leaf water status within the leaf. Model results suggest that species-specific 'economics' of stomatal behaviour may play an important role in differentiating species along the continuum of isohydric to anisohydric behaviour; specifically, we show that non-stomatal and demand limitations may reduce stomatal conductance and increase leaf water potential, promoting wide safety margins characteristic of isohydric species. We used model results to develop a diagnostic framework to identify the most likely limiting mechanism to stomatal functioning during drought and showed that many of those features were commonly observed in field observations of tree water use dynamics. Direct comparisons of modelled and measured stomatal conductance further indicated that non-stomatal and demand limitations reproduced observed patterns of tree water use well for an isohydric species but that a hydraulic limitation likely applies in the case of an anisohydric species.},
author = {Novick, Kimberly A. and Miniat, Chelcy F. and Vose, James M.},
doi = {10.1111/pce.12657},
issn = {13653040},
journal = {Plant, Cell {\&} Environment},
keywords = {Anisohydric,Capacitance,Isohydric,Stomatal conductance,Transpiration,Water use efficiency},
number = {3},
pages = {583--596},
pmid = {26466749},
title = {{Drought limitations to leaf-level gas exchange: Results from a model linking stomatal optimization and cohesion–tension theory}},
volume = {39},
year = {2016}
}
@article{ODell2018,
abstract = {Abstract. Since September 2014, NASA's Orbiting Carbon Observatory-2 (OCO-2) satellite has been taking measurements of reflected solar spectra and using them to infer atmospheric carbon dioxide levels. This work provides details of the OCO-2 retrieval algorithm, versions 7 and 8, used to derive the column-averaged dry air mole fraction of atmospheric CO2 (XCO2) for the roughly 100000 cloud-free measurements recorded by OCO-2 each day. The algorithm is based on the Atmospheric Carbon Observations from Space (ACOS) algorithm which has been applied to observations from the Greenhouse Gases Observing SATellite (GOSAT) since 2009, with modifications necessary for OCO-2. Because high accuracy, better than 0.25{\%}, is required in order to accurately infer carbon sources and sinks from XCO2, significant errors and regional-scale biases in the measurements must be minimized. We discuss efforts to filter out poor-quality measurements, and correct the remaining good-quality measurements to minimize regional-scale biases. Updates to the radiance calibration and retrieval forward model in version 8 have improved many aspects of the retrieved data products. The version 8 data appear to have reduced regional-scale biases overall, and demonstrate a clear improvement over the version 7 data. In particular, error variance with respect to TCCON was reduced by 20{\%} over land and 40{\%} over ocean between versions 7 and 8, and nadir and glint observations over land are now more consistent. While this paper documents the significant improvements in the ACOS algorithm, it will continue to evolve and improve as the CO2 data record continues to expand. ]]{\textgreater}},
author = {O'Dell, Christopher W. and Eldering, Annmarie and Wennberg, Paul O. and Crisp, David and Gunson, Michael R. and Fisher, Brendan and Frankenberg, Christian and Kiel, Matth{\"{a}}us and Lindqvist, Hannakaisa and Mandrake, Lukas and Merrelli, Aronne and Natraj, Vijay and Nelson, Robert R. and Osterman, Gregory B. and Payne, Vivienne H. and Taylor, Thomas E. and Wunch, Debra and Drouin, Brian J. and Oyafuso, Fabiano and Chang, Albert and McDuffie, James and Smyth, Michael and Baker, David F. and Basu, Sourish and Chevallier, Fr{\'{e}}d{\'{e}}ric and Crowell, Sean M. R. and Feng, Liang and Palmer, Paul I. and Dubey, Mavendra and Garc{\'{i}}a, Omaira E. and Griffith, David W. T. and Hase, Frank and Iraci, Laura T. and Kivi, Rigel and Morino, Isamu and Notholt, Justus and Ohyama, Hirofumi and Petri, Christof and Roehl, Coleen M. and Sha, Mahesh K. and Strong, Kimberly and Sussmann, Ralf and Te, Yao and Uchino, Osamu and Velazco, Voltaire A.},
doi = {10.5194/amt-11-6539-2018},
issn = {1867-8548},
journal = {Atmospheric Measurement Techniques},
month = {dec},
number = {12},
pages = {6539--6576},
title = {{Improved retrievals of carbon dioxide from Orbiting Carbon Observatory-2 with the version 8 ACOS algorithm}},
url = {https://www.atmos-meas-tech.net/11/6539/2018/},
volume = {11},
year = {2018}
}
@article{OSullivan2019,
abstract = {Abstract The terrestrial carbon sink has increased since the turn of this century at a time of increased fossil fuel burning, yet the mechanisms enhancing this sink are not fully understood. Here we assess the hypothesis that regional increases in nitrogen deposition since the early 2000s has alleviated nitrogen limitation and worked in tandem with enhanced CO2 fertilization to increase ecosystem productivity and carbon sequestration, providing a causal link between the parallel increases in emissions and the global land carbon sink. We use the Community Land Model (CLM4.5-BGC) to estimate the influence of changes in atmospheric CO2, nitrogen deposition, climate, and their interactions to changes in net primary production and net biome production. We focus on two periods, 1901–2016 and 1990–2016, to estimate changes in land carbon fluxes relative to historical and contemporary baselines, respectively. We find that over the historical period, nitrogen deposition (14{\%}) and carbon-nitrogen synergy (14{\%}) were significant contributors to the current terrestrial carbon sink, suggesting that long-term increases in nitrogen deposition led to a substantial increase in CO2 fertilization. However, relative to the contemporary baseline, changes in nitrogen deposition and carbon-nitrogen synergy had no substantial contribution to the 21st century increase in global carbon uptake. Nonetheless, we find that increased nitrogen deposition in East Asia since the early 1990s contributed 50{\%} to the overall increase in net biome production over this region, highlighting the importance of carbon-nitrogen interactions. Therefore, potential large-scale changes in nitrogen deposition could have a significant impact on terrestrial carbon cycling and future climate.},
author = {O'Sullivan, Michael and Spracklen, Dominick V and Batterman, Sarah and Arnold, Steve R and Gloor, Manuel and Buermann, Wolfgang},
doi = {10.1029/2018GB005922},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
month = {jan},
number = {2},
pages = {163--180},
title = {{Have synergies between nitrogen deposition and atmospheric CO2 driven the recent enhancement of the terrestrial carbon sink?}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GB005922 https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GB005922},
volume = {33},
year = {2019}
}
@article{Obermeier2017a,
author = {Obermeier, W. A. and Lehnert, L. W. and Kammann, C. I. and M{\"{u}}ller, C. and Gr{\"{u}}nhage, L. and Luterbacher, J. and Erbs, M. and Moser, G. and Seibert, R. and Yuan, N. and Bendix, J.},
doi = {10.1038/nclimate3191},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {feb},
number = {2},
pages = {137--141},
title = {{Reduced CO2 fertilization effect in temperate C3 grasslands under more extreme weather conditions}},
volume = {7},
year = {2017}
}
@article{Oka2015,
abstract = {Temperature and salinity data from Argo profiling floats during 2005–2014 were analyzed to examine the decadal variability of the North Pacific Subtropical Mode Water (STMW) in relation to that of the Kuroshio Extension (KE) system. The formation volume of STMW in the southern recirculation gyre of KE in the cooling season was larger during the stable KE period after 2010 than the unstable KE period of 2006–2009 by 50 {\%}. As a result, the volume and spatial extent of STMW increased (decreased) in the formation region during the stable (unstable) KE period, as well as in the southern, downstream region with a time lag of 1–2 years. The decadal expansion and contraction of STMW were also detected by shipboard observations conducted routinely in the most downstream region near the western boundary, in terms of not only physical, but also biogeochemical parameters. After 2010, enhanced subduction of STMW consistently increased dissolved oxygen, pH, and aragonite saturation state and decreased potential vorticity, apparent oxygen utilization, nitrate, and dissolved inorganic carbon, among which changes of dissolved inorganic carbon, pH, and aragonite saturation state were against their long-term trends. These results indicate a new mechanism consisting of westward sea surface height anomaly propagation, the KE state transition, and the STMW formation and subduction, by which the climate variability affects physical and biogeochemical structures in the ocean's interior and potentially impacts the surface ocean acidification trend and biological production.},
author = {Oka, Eitarou and Qiu, Bo and Takatani, Yusuke and Enyo, Kazutaka and Sasano, Daisuke and Kosugi, Naohiro and Ishii, Masao and Nakano, Toshiya and Suga, Toshio},
doi = {10.1007/s10872-015-0300-x},
issn = {0916-8370},
journal = {Journal of Oceanography},
month = {aug},
number = {4},
pages = {389--400},
title = {{Decadal variability of Subtropical Mode Water subduction and its impact on biogeochemistry}},
url = {https://doi.org/10.1007/s10872-015-0300-x http://link.springer.com/10.1007/s10872-015-0300-x},
volume = {71},
year = {2015}
}
@article{Oka2019,
abstract = {Abstract Half-century-long observations at the 137°E repeat hydrographic section across the western North Pacific have been analyzed to demonstrate remotely forced decadal physical and biogeochemical variability of Subtropical Mode Water (STMW) over the last 40 years. During unstable periods of the Kuroshio Extension (KE) that lagged the warm phase of the Pacific Decadal Oscillation by 3?4 years, high regional eddy activity reduced the formation rate and salinity of STMW in its main formation region south of the KE. At the 137°E section south of Japan, decreasing southwestward advection of oxygen-rich STMW from the formation region resulted in decreases of its cross-sectional area, dissolved oxygen, pH, and aragonite saturation state and increases of nutrients and dissolved inorganic carbon, among which changes of the carbon system parameters accelerated their long-term trends. Such changes reversed and acidification slowed down during stable-KE periods, especially in the current period since 2010 exhibiting a hiatus of acidification.},
annote = {doi: 10.1029/2018GL081330},
author = {Oka, Eitarou and Yamada, Kodai and Sasano, Daisuke and Enyo, Kazutaka and Nakano, Toshiya and Ishii, Masao},
doi = {10.1029/2018GL081330},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {feb},
number = {3},
pages = {1555--1561},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Remotely forced decadal physical and biogeochemical variability of North Pacific Subtropical Mode Water over the last 40 years}},
url = {https://doi.org/10.1029/2018GL081330 http://doi.wiley.com/10.1029/2018GL081330},
volume = {46},
year = {2019}
}
@article{Olafsson2009,
abstract = {Abstract. The Iceland Sea is one part of the Nordic Seas. Cold Arctic Water prevails there and the deep-water is an important source of North Atlantic Deep Water. We have evaluated time series observations of measured pCO2 and total CO2 concentration from discrete seawater samples during 1985–2008 for the surface and 1994–2008 for deep-water, and following changes in response to increasing atmospheric carbon dioxide. The surface pH in winter decreases at a rate of 0.0024 yr−1, which is 50{\%} faster than average yearly rates at two subtropical time series stations, BATS and ESTOC. In the deep-water regime ({\textgreater}1500 m), the rate of pH decline is a quarter of that observed in surface waters. The surface seawater carbonate saturation states ($\Omega$) are about 1.5 for aragonite and 2.5 for calcite, about half of levels found in subtropical surface waters. During 1985–2008, the degree of saturation ($\Omega$) decreased at an average rate of 0.0072 yr−1 for aragonite and 0.012 yr−1 for calcite. The aragonite saturation horizon is currently at 1710 m and shoaling at 4 m yr−1. Based on this rate of shoaling and on the local hypsography, each year another 800 km2 of seafloor becomes exposed to waters that have become undersaturated with respect to aragonite.},
author = {Olafsson, J and Olafsdottir, S R and Benoit-Cattin, A and Danielsen, M and Arnarson, T S and Takahashi, T},
doi = {10.5194/bg-6-2661-2009},
issn = {1726-4189},
journal = {Biogeosciences},
month = {nov},
number = {11},
pages = {2661--2668},
title = {{Rate of Iceland Sea acidification from time series measurements}},
url = {https://bg.copernicus.org/articles/6/2661/2009/},
volume = {6},
year = {2009}
}
@article{Olefeldt2016,
abstract = {Thermokarst is the process whereby the thawing of ice-rich permafrost ground causes land subsidence, resulting in development of distinctive landforms. Accelerated thermokarst due to climate change will damage infrastructure, but also impact hydrology, ecology and biogeochemistry. Here, we present a circumpolar assessment of the distribution of thermokarst landscapes, defined as landscapes comprised of current thermokarst landforms and areas susceptible to future thermokarst development. At 3.6 × 106 km2, thermokarst landscapes are estimated to cover ∼20{\%} of the northern permafrost region, with approximately equal contributions from three landscape types where characteristic wetland, lake and hillslope thermokarst landforms occur. We estimate that approximately half of the below-ground organic carbon within the study region is stored in thermokarst landscapes. Our results highlight the importance of explicitly considering thermokarst when assessing impacts of climate change, including future landscape greenhouse gas emissions, and provide a means for assessing such impacts at the circumpolar scale.},
author = {Olefeldt, D and Goswami, S and Grosse, G and Hayes, D and Hugelius, G and Kuhry, P and McGuire, A D and Romanovsky, V E and Sannel, A B K and Schuur, E A G and Turetsky, M R},
doi = {10.1038/ncomms13043},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {13043},
title = {{Circumpolar distribution and carbon storage of thermokarst landscapes}},
url = {https://doi.org/10.1038/ncomms13043},
volume = {7},
year = {2016}
}
@misc{https://doi.org/10.3334/ornldaac/1332,
address = {Oak Ridge, TN, USA},
author = {Olefeldt, D and Goswami, S and Grosse, G and Hayes, D J and Hugelius, G and Kuhry, P and Sannel, B and Schuur, E A G and Turetsky, M R},
doi = {10.3334/ORNLDAAC/1332},
publisher = {ORNL Distributed Active Archive Center},
title = {{Arctic Circumpolar Distribution and Soil Carbon of Thermokarst Landscapes, 2015}},
url = {http://daac.ornl.gov/cgi-bin/dsviewer.pl?ds{\_}id=1332},
year = {2016}
}
@article{OlivarezLyle2006,
author = {{Olivarez Lyle}, Annette and Lyle, Mitchell W.},
doi = {10.1029/2005PA001230},
issn = {08838305},
journal = {Paleoceanography},
month = {jun},
number = {2},
pages = {PA2007},
title = {{Missing organic carbon in Eocene marine sediments: Is metabolism the biological feedback that maintains end-member climates?}},
url = {http://doi.wiley.com/10.1029/2005PA001230},
volume = {21},
year = {2006}
}
@article{Olsen2020a,
author = {Olsen, A and Lange, N and Key, R M and Tanhua, T and Bittig, H C and Kozyr, A and {\'{A}}lvarez, M and Azetsu-Scott, K and Becker, S and Brown, P J and Carter, B R and da Cunha, L and Feely, R A and van Heuven, S and Hoppema, M and Ishii, M and Jeansson, E and Jutterstr{\"{o}}m, S and Landa, C S and Lauvset, S K and Michaelis, P and Murata, A and P{\'{e}}rez, F F and Pfeil, B and Schirnick, C and Steinfeldt, R and Suzuki, T and Tilbrook, B and Velo, A and Wanninkhof, R and Woosley, R J},
doi = {10.5194/essd-12-3653-2020},
journal = {Earth System Science Data},
number = {4},
pages = {3653--3678},
title = {{An updated version of the global interior ocean biogeochemical data product, GLODAPv2.2020}},
url = {https://essd.copernicus.org/articles/12/3653/2020/},
volume = {12},
year = {2020}
}
@article{Ono2019,
abstract = {Abstract Because annual anthropogenic CO2 emissions have grown rapidly over the past decades, there is a concern that anthropogenic CO2 invasion into the ocean may also have caused the rate of ocean acidification to increase. Here, we report the decadal and longer-term variability in the rates of change of inorganic carbon variables since the early 1980s in surface seawaters of various oceanic regions along the 137°E repeat line in the western North Pacific. In the subtropical frontal zone, we found that the mean rate of acidification tracked the acceleration of the atmospheric CO2 increase; during 2008?2017, the rate of acidification was 30{\%} faster than during 1983?2017. In the Kuroshio Recirculation and tropical zone, acidification trends were clear, but the trends were modulated by decadal variability associated with temporal variability in regional ocean circulation.},
annote = {doi: 10.1029/2019GL085121},
author = {Ono, Hisashi and Kosugi, Naohiro and Toyama, Katsuya and Tsujino, Hiroyuki and Kojima, Atsushi and Enyo, Kazutaka and Iida, Yosuke and Nakano, Toshiya and Ishii, Masao},
doi = {10.1029/2019GL085121},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {acceleration,atmospheric CO2 increase,decadal variability,meridional variability,ocean acidification,western North Pacific},
month = {nov},
number = {22},
pages = {13161--13169},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Acceleration of Ocean Acidification in the Western North Pacific}},
url = {https://doi.org/10.1029/2019GL085121 https://onlinelibrary.wiley.com/doi/10.1029/2019GL085121},
volume = {46},
year = {2019}
}
@article{Orr2005,
abstract = {Today's surface ocean is saturated with respect to calcium carbonate, but increasing atmospheric carbon dioxide concentrations are reducing ocean pH and carbonate ion concentrations, and thus the level of calcium carbonate saturation. Experimental evidence suggests that if these trends continue, key marine organisms - such as corals and some plankton - will have difficulty maintaining their external calcium carbonate skeletons. Here we use 13 models of the ocean-carbon cycle to assess calcium carbonate saturation under the IS92a 'business-as-usual' scenario for future emissions of anthropogenic carbon dioxide. In our projections, Southern Ocean surface waters will begin to become undersaturated with respect to aragonite, a metastable form of calcium carbonate, by the year 2050. By 2100, this undersaturation could extend throughout the entire Southern Ocean and into the subarctic Pacific Ocean. When live pteropods were exposed to our predicted level of undersaturation during a two-day shipboard experiment, their aragonite shells showed notable dissolution. Our findings indicate that conditions detrimental to high-latitude ecosystems could develop within decades, not centuries as suggested previously. {\textcopyright} 2005 Nature Publishing Group.},
author = {Orr, James C. and Fabry, Victoria J. and Aumont, Olivier and Bopp, Laurent and Doney, Scott C. and Feely, Richard A. and Gnanadesikan, Anand and Gruber, Nicolas and Ishida, Akio and Joos, Fortunat and Key, Robert M. and Lindsay, Keith and Maier-Reimer, Ernst and Matear, Richard and Monfray, Patrick and Mouchet, Anne and Najjar, Raymond G. and Plattner, Gian Kasper and Rodgers, Keith B. and Sabine, Christopher L. and Sarmiento, Jorge L. and Schlitzer, Reiner and Slater, Richard D. and Totterdell, Ian J. and Weirig, Marie France and Yamanaka, Yasuhiro and Yool, Andrew},
doi = {10.1038/nature04095},
issn = {00280836},
journal = {Nature},
number = {7059},
pages = {681--686},
pmid = {16193043},
title = {{Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms}},
volume = {437},
year = {2005}
}
@article{Orselli2018a,
author = {Orselli, Iole B.M. and Kerr, Rodrigo and Ito, Rosane G. and Tavano, Virginia M. and Mendes, Carlos Rafael B. and Garcia, Carlos A.E.},
doi = {10.1016/j.jmarsys.2017.10.007},
issn = {09247963},
journal = {Journal of Marine Systems},
month = {feb},
pages = {1--14},
title = {{How fast is the Patagonian shelf-break acidifying?}},
volume = {178},
year = {2018}
}
@article{Ortega2019,
author = {Ortega, Alejandra and Geraldi, Nathan R. and Alam, Intikhab and Kamau, Allan A. and Acinas, Silvia G. and Logares, Ramiro and Gasol, Josep M. and Massana, Ramon and Krause-Jensen, Dorte and Duarte, Carlos M.},
doi = {10.1038/s41561-019-0421-8},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {sep},
number = {9},
pages = {748--754},
title = {{Important contribution of macroalgae to oceanic carbon sequestration}},
url = {http://www.nature.com/articles/s41561-019-0421-8},
volume = {12},
year = {2019}
}
@article{Osborne2020,
author = {Osborne, Emily B. and Thunell, Robert C. and Gruber, Nicolas and Feely, Richard A. and Benitez-Nelson, Claudia R.},
doi = {10.1038/s41561-019-0499-z},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jan},
number = {1},
pages = {43--49},
title = {{Decadal variability in twentieth-century ocean acidification in the California Current Ecosystem}},
url = {http://www.nature.com/articles/s41561-019-0499-z},
volume = {13},
year = {2020}
}
@article{Oschlies2018,
abstract = {Direct observations indicate that the global ocean oxygen inventory is decreasing. Climate models consistently confirm this decline and predict continuing and accelerating ocean deoxygenation. However, current models (1) do not reproduce observed patterns for oxygen changes in the ocean's thermocline; (2) underestimate the temporal variability of oxygen concentrations and air–sea fluxes inferred from time-series observations; and (3) generally simulate only about half the oceanic oxygen loss inferred from observations. We here review current knowledge about the mechanisms and drivers of oxygen changes and their variation with region and depth over the world's oceans. Warming is considered a major driver: in part directly, via solubility effects, and in part indirectly, via changes in circulation, mixing and oxygen respiration. While solubility effects have been quantified and found to dominate deoxygenation near the surface, a quantitative understanding of contributions from other mechanisms is still lacking. Current models may underestimate deoxygenation because of unresolved transport processes, unaccounted for variations in respiratory oxygen demand, or missing biogeochemical feedbacks. Dedicated observational programmes are required to better constrain biological and physical processes and their representation in models to improve our understanding and predictions of patterns and intensity of future oxygen change.},
author = {Oschlies, Andreas and Brandt, Peter and Stramma, Lothar and Schmidtko, Sunke},
doi = {10.1038/s41561-018-0152-2},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jul},
number = {7},
pages = {467--473},
title = {{Drivers and mechanisms of ocean deoxygenation}},
url = {https://doi.org/10.1038/s41561-018-0152-2 http://www.nature.com/articles/s41561-018-0152-2},
volume = {11},
year = {2018}
}
@article{Oschlies2010e,
abstract = {Abstract. Recent suggestions to slow down the increase in atmospheric carbon dioxide have included ocean fertilization by addition of the micronutrient iron to Southern Ocean surface waters, where a number of natural and artificial iron fertilization experiments have shown that low ambient iron concentrations limit phytoplankton growth. Using a coupled carbon-climate model with the marine biology's response to iron addition calibrated against data from natural iron fertilization experiments, we examine biogeochemical side effects of a hypothetical large-scale Southern Ocean Iron Fertilization (OIF) that need to be considered when attempting to account for possible OIF-induced carbon offsets. In agreement with earlier studies our model simulates an OIF-induced increase in local air-sea CO2 fluxes by about 73 GtC over a 100-year period, which amounts to about 48{\%} of the OIF-induced increase in organic carbon export out of the fertilized area. Offsetting CO2 return fluxes outside the region and after stopping the fertilization at 1, 7, 10, 50, and 100 years are quantified for a typical accounting period of 100 years. For continuous Southern Ocean iron fertilization, the CO2 return flux outside the fertilized area cancels about 20{\%} of the fertilization-induced CO2 air-sea flux within the fertilized area on a 100-yr timescale. This "leakage" effect has a radiative impact more than twice as large as the simulated enhancement of marine N2O emissions. Other side effects not yet discussed in terms of accounting schemes include a decrease in Southern Ocean oxygen levels and a simultaneous shrinking of tropical suboxic areas, and accelerated ocean acidification in the entire water column in the Southern Ocean at the expense of reduced globally-averaged surface-water acidification. A prudent approach to account for the OIF-induced carbon sequestration would account for global air-sea CO2 fluxes rather than for local fluxes into the fertilized area only. However, according to our model, this would underestimate the potential for offsetting CO2 emissions by about 20{\%} on a 100 year accounting timescale. We suggest that a fair accounting scheme applicable to both terrestrial and marine carbon sequestration has to be based on emission offsets rather than on changes in individual carbon pools.},
author = {Oschlies, A. and Koeve, W. and Rickels, W. and Rehdanz, K.},
doi = {10.5194/bg-7-4017-2010},
issn = {1726-4189},
journal = {Biogeosciences},
month = {dec},
number = {12},
pages = {4017--4035},
title = {{Side effects and accounting aspects of hypothetical large-scale Southern Ocean iron fertilization}},
url = {https://bg.copernicus.org/articles/7/4017/2010/},
volume = {7},
year = {2010}
}
@article{Oschlies2010a,
author = {Oschlies, Andreas and Pahlow, M. and Yool, A. and Matear, R. J.},
doi = {10.1029/2009GL041961},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {feb},
number = {4},
pages = {L04701},
title = {{Climate engineering by artificial ocean upwelling: Channelling the sorcerer's apprentice}},
volume = {37},
year = {2010}
}
@article{Osma2020a,
abstract = {The interplay of coastal oceanographic processes usually results in partial pressures of CO2 (pCO2) higher than expected from the equilibrium with the atmosphere and even higher than those expected by the end of the century. Although this is a well-known situation, the natural variability of seawater chemistry at the locations from which tested organisms or communities originate is seldom considered in ocean acidification experiments. In this work, we aimed to evaluate the role of the carbonate chemistry dynamics in shaping the response of coastal phytoplankton communities to increased pCO2 levels. The study was conducted at two coastal ecosystems off Chile, the Valdivia River estuary and the coastal upwelling ecosystem in the Arauco Gulf. We characterized the seasonal variability (winter/summer) of the hydrographic conditions, the carbonate system parameters, and the phytoplankton community structure at both sites. The results showed that carbonate chemistry dynamics in the estuary were mainly related to seasonal changes in freshwater discharges, with acidic and corrosive conditions dominating in winter. In the Arauco Gulf, these conditions were observed in summer, mainly associated with the upwelling of cold and high pCO2 ({\textgreater}1,000 $\mu$atm) waters. Diatoms dominated the phytoplankton communities at both sites, yet the one in Valdivia was more diverse. Only certain phytoplankton groups in this latter ecosystem showed a significant correlations with the carbonate system parameters. When the impact of elevated pCO2 levels was investigated by pCO2 manipulation experiments, we did not observe any significant effect on the biomass of either of the two communities. Changes in the phytoplankton species composition and abundance during the incubations were related to other factors, such as competition and growth phases. Our findings highlight the importance of the natural variability of coastal ecosystems and the potential for local adaptation in determining responses of coastal phytoplankton communities to increased pCO2 levels.},
author = {Osma, Natalia and Latorre-Mel{\'{i}}n, Laura and Jacob, B{\'{a}}rbara and Contreras, Paulina Y and von Dassow, Peter and Vargas, Cristian A},
doi = {10.3389/fmars.2020.00323},
isbn = {2296-7745},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {may},
pages = {323},
title = {{Response of Phytoplankton Assemblages From Naturally Acidic Coastal Ecosystems to Elevated pCO2}},
volume = {7},
year = {2020}
}
@article{Pepin2001,
abstract = {The Vostok ice contains fingerprints of atmospheric greenhouse trace gases, Antarctic temperature, Northern Hemisphere temperature, and global ice volume/sea level changes during the last glacial-interglacial cycles and thus allows us to investigate the sequences of these climatic events, in particular during the transitions from full glacial to interglacial conditions. The use of the updated CO2 record presented here and a reexamination of the sea level proxy confirm that the succession of changes has been similar through each of the four marked transitions found at Vostok. Antarctic air temperature and CO2 increase in parallel and almost synchronously, while the rapid warmings over Greenland take place during the last half of their change and coincide with the marked decay in continental ice volume. The Vostok results thus emphasize a fundamental difference between South and North in terms of climate dynamics. Our results confirm the role of CO2 as an important amplifier of the glacial-interglacial warming in the South. It appears also that the marked warming observed at high northern latitudes (lagging behind the CO2 increase by several thousand years) is roughly synchronous with the decay of the northern ice sheets, suggesting a major role of climatic feedback due to this decay. Such a climatic scenario is supported by sensitivity experiments performed with the LLN 2-D model forced by the Northern Hemisphere insolation and CO2. Model results indicate that the decay of the northern ice sheets and the Northern Hemisphere temperature depend primarily on the northern summer insolation. These results, nevertheless, could be affected if mechanisms specific to the Southern Hemisphere appear to play a major role in driving the Northern Hemisphere climate. The model also helps to constrain the time response of ice volume to insolation and CO2 changes.},
author = {P{\'{e}}pin, L. and Raynaud, D. and Barnola, J.-M. and Loutre, M. F.},
doi = {10.1029/2001JD900117},
isbn = {0148-0227},
issn = {01480227},
journal = {Journal of Geophysical Research: Atmospheres},
month = {dec},
number = {D23},
pages = {31885--31892},
title = {{Hemispheric roles of climate forcings during glacial–interglacial transitions as deduced from the Vostok record and LLN-2D model experiments}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2001JD900117 http://doi.wiley.com/10.1029/2001JD900117},
volume = {106},
year = {2001}
}
@article{Perez2013,
abstract = {Uptake of atmospheric carbon dioxide in the subpolar North Atlantic Ocean declined rapidly between 1990 and 2006. This reduction in carbon dioxide uptake was related to warming at the sea surface, which—according to model simulations—coincided with a reduction in the Atlantic meridional overturning circulation. The extent to which the slowdown of this circulation system—which transports warm surface waters to the northern high latitudes, and cool deep waters south—contributed to the reduction in carbon uptake has remained uncertain. Here, we use data on the oceanic transport of volume, heat and carbon dioxide to track carbon dioxide uptake in the subtropical and subpolar regions of the North Atlantic Ocean over the past two decades. We separate anthropogenic carbon from natural carbon by assuming that the latter corresponds to a pre-industrial atmosphere, whereas the remaining is anthropogenic. We find that the uptake of anthropogenic carbon dioxide—released by human activities—occurred almost exclusively in the subtropical gyre. In contrast, natural carbon dioxide uptake—which results from natural Earth system processes—dominated in the subpolar gyre. We attribute the weakening of contemporary carbon dioxide uptake in the subpolar North Atlantic to a reduction in the natural component. We show that the slowdown of the meridional overturning circulation was largely responsible for the reduction in carbon uptake, through a reduction of oceanic heat loss to the atmosphere, and for the concomitant decline in anthropogenic CO2 storage in subpolar waters.},
author = {P{\'{e}}rez, Fiz F and Mercier, Herl{\'{e}} and V{\'{a}}zquez-Rodr{\'{i}}guez, Marcos and Lherminier, Pascale and Velo, Anton and Pardo, Paula C and Ros{\'{o}}n, Gabriel and R{\'{i}}os, Aida F},
doi = {10.1038/ngeo1680},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {feb},
number = {2},
pages = {146--152},
publisher = {Nature Publishing Group},
title = {{Atlantic Ocean CO2 uptake reduced by weakening of the meridional overturning circulation}},
url = {http://dx.doi.org/10.1038/ngeo1680 10.1038/ngeo1680 https://www.nature.com/articles/ngeo1680{\#}supplementary-information http://www.nature.com/articles/ngeo1680},
volume = {6},
year = {2013}
}
@article{Perez2018a,
author = {P{\'{e}}rez, Fiz F and Fontela, Marcos and Garc{\'{i}}a-Ib{\'{a}}{\~{n}}ez, Maribel I and Mercier, Herl{\'{e}} and Velo, Anton and Lherminier, Pascale and Zunino, Patricia and de la Paz, Mercedes and Alonso-P{\'{e}}rez, Fernando and Guallart, Elisa F and Padin, Xose A},
doi = {10.1038/nature25493},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7693},
pages = {515--518},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Meridional overturning circulation conveys fast acidification to the deep Atlantic Ocean}},
url = {https://doi.org/10.1038/nature25493 10.1038/nature25493 http://www.nature.com/articles/nature25493},
volume = {554},
year = {2018}
}
@article{Perez-Ramrez2003,
abstract = {Nitric acid production represents the largest source of N2O in the chemical industry, with a global annual emission of 400kt N2O. The high impact of N2O on the environment as greenhouse gas and stratospheric ozone depletor, and the ongoing agreements and prospective regulations calls for the development of efficient and economical systems for N2O mitigation, but no mature commercial technology is yet available. In this review, the current state-of-the-art for N2O control in the nitric acid manufacture is presented. The formation of N2O and the process are analyzed and several options for reducing its emissions are discussed, depending on the position in the process. Primary abatement options deals with modifications in the ammonia oxidation catalyst, secondary abatement with options between the ammonia converter and the absorber, tertiary abatement with options in the tail-gas upstream of the expander, and quaternary abatement with options in the tail-gas downstream of the expander. The abatement technologies are evaluated based on the technical advantages and disadvantages, and cost efficiency.},
author = {P{\'{e}}rez-Ramı́rez, J and Kapteijn, F and Sch{\"{o}}ffel, K and Moulijn, J.A},
doi = {10.1016/S0926-3373(03)00026-2},
issn = {09263373},
journal = {Applied Catalysis B: Environmental},
month = {aug},
number = {2},
pages = {117--151},
publisher = {Elsevier},
title = {{Formation and control of N2O in nitric acid production}},
url = {https://www.sciencedirect.com/science/article/pii/S0926337303000262?via{\%}3Dihub https://linkinghub.elsevier.com/retrieve/pii/S0926337303000262},
volume = {44},
year = {2003}
}
@article{Palmer2019,
abstract = {Tropical ecosystems are large carbon stores that are vulnerable to climate change. The sparseness of ground-based measurements has precluded verification of these ecosystems being a net annual source (+ve) or sink (−ve) of atmospheric carbon. We show that two independent satellite data sets of atmospheric carbon dioxide (CO2), interpreted using independent models, are consistent with the land tropics being a net annual carbon emission of (medianmaximumminimum) 1.03+1.73−0.20 and 1.60+2.11+1.39 petagrams (PgC) in 2015 and 2016, respectively. These pan-tropical estimates reflect unexpectedly large net emissions from tropical Africa of 1.48+1.95+0.80 PgC in 2015 and 1.65+2.42+1.14 PgC in 2016. The largest carbon uptake is over the Congo basin, and the two loci of carbon emissions are over western Ethiopia and western tropical Africa, where there are large soil organic carbon stores and where there has been substantial land use change. These signals are present in the space-borne CO2 record from 2009 onwards.},
author = {Palmer, Paul I. and Feng, Liang and Baker, David and Chevallier, Fr{\'{e}}d{\'{e}}ric and B{\"{o}}sch, Hartmut and Somkuti, Peter},
doi = {10.1038/s41467-019-11097-w},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {3344},
title = {{Net carbon emissions from African biosphere dominate pan-tropical atmospheric CO2 signal}},
url = {http://www.nature.com/articles/s41467-019-11097-w},
volume = {10},
year = {2019}
}
@article{Pandey2017,
abstract = {Year-to-year variations in the atmospheric methane (CH4) growth rate show significant correlation with climatic drivers. The second half of 2010 and the first half of 2011 experienced the strongest La Ni{\~{n}}a since the early 1980s, when global surface networks started monitoring atmospheric CH4 mole fractions. We use these surface measurements, retrievals of column-averaged CH4 mole fractions from GOSAT, new wetland inundation estimates, and atmospheric $\delta$13C-CH4 measurements to estimate the impact of this strong La Ni{\~{n}}a on the global atmospheric CH4 budget. By performing atmospheric inversions, we find evidence of an increase in tropical CH4 emissions of ∼6–9 TgCH4 yr−1 during this event. Stable isotope data suggest that biogenic sources are the cause of this emission increase. We find a simultaneous expansion of wetland area, driven by the excess precipitation over the Tropical continents during the La Ni{\~{n}}a. Two process-based wetland models predict increases in wetland area consistent with observationally-constrained values, but substantially smaller per-area CH4 emissions, highlighting the need for improvements in such models. Overall, tropical wetland emissions during the strong La Ni{\~{n}}a were at least by 5{\%} larger than the long-term mean.},
author = {Pandey, Sudhanshu and Houweling, Sander and Krol, Maarten and Aben, Ilse and Monteil, Guillaume and Nechita-Banda, Narcisa and Dlugokencky, Edward J and Detmers, Rob and Hasekamp, Otto and Xu, Xiyan and Riley, William J and Poulter, Benjamin and Zhang, Zhen and McDonald, Kyle C and White, James W C and Bousquet, Philippe and R{\"{o}}ckmann, Thomas},
doi = {10.1038/srep45759},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {45759},
publisher = {The Author(s)},
title = {{Enhanced methane emissions from tropical wetlands during the 2011 La Ni{\~{n}}a}},
url = {http://dx.doi.org/10.1038/srep45759 http://www.nature.com/articles/srep45759},
volume = {7},
year = {2017}
}
@article{Pangala2017,
author = {Pangala, Sunitha R and Enrich-Prast, Alex and Basso, Luana S and Peixoto, Roberta Bittencourt and Bastviken, David and Hornibrook, Edward R C and Gatti, Luciana V and Marotta, Humberto and Calazans, Luana Silva Braucks and Sakuragui, Cassia M{\^{o}}nica and Bastos, Wanderley Rodrigues and Malm, Olaf and Gloor, Emanuel and Miller, John Bharat and Gauci, Vincent},
doi = {10.1038/nature24639},
issn = {0028-0836},
journal = {Nature},
month = {dec},
number = {7684},
pages = {230--234},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Large emissions from floodplain trees close the Amazon methane budget}},
url = {http://dx.doi.org/10.1038/nature24639 http://10.0.4.14/nature24639 https://www.nature.com/articles/nature24639{\#}supplementary-information http://www.nature.com/articles/nature24639},
volume = {552},
year = {2017}
}
@article{tc-12-123-2018,
abstract = {55∘ N) from 2000 to 2300. Widespread talik at depth is projected across most of the NHL permafrost region (14 million km2) by 2300, 6.2 million km2 of which is projected to become a long-term C source, emitting 10 Pg C by 2100, 50 Pg C by 2200, and 120 Pg C by 2300, with few signs of slowing. Roughly half of the projected C source region is in predominantly warm sub-Arctic permafrost following talik onset. This region emits only 20 Pg C by 2300, but the CLM4.5 estimate may be biased low by not accounting for deep C in yedoma. Accelerated decomposition of deep soil C following talik onset shifts the ecosystem C balance away from surface dominant processes (photosynthesis and litter respiration), but sink-to-source transition dates are delayed by 20–200 years by high ecosystem productivity, such that talik peaks early (∼ 2050s, although borehole data suggest sooner) and C source transition peaks late (∼ 2150–2200). The remaining C source region in cold northern Arctic permafrost, which shifts to a net source early (late 21st century), emits 5 times more C (95 Pg C) by 2300, and prior to talik formation due to the high decomposition rates of shallow, young C in organic-rich soils coupled with low productivity. Our results provide important clues signaling imminent talik onset and C source transition, including (1) late cold-season (January–February) soil warming at depth (∼ 2 m), (2) increasing cold-season emissions (November–April), and (3) enhanced respiration of deep, old C in warm permafrost and young, shallow C in organic-rich cold permafrost soils. Our results suggest a mosaic of processes that govern carbon source-to-sink transitions at high latitudes and emphasize the urgency of monitoring soil thermal profiles, organic C age and content, cold-season CO2 emissions, and atmospheric 14CO2 as key indicators of the permafrost C feedback.]]{\textgreater}},
author = {Parazoo, Nicholas C and Koven, Charles D and Lawrence, David M and Romanovsky, Vladimir and Miller, Charles E},
doi = {10.5194/tc-12-123-2018},
issn = {1994-0424},
journal = {The Cryosphere},
month = {jan},
number = {1},
pages = {123--144},
title = {{Detecting the permafrost carbon feedback: talik formation and increased cold-season respiration as precursors to sink-to-source transitions}},
url = {https://tc.copernicus.org/articles/12/123/2018/},
volume = {12},
year = {2018}
}
@article{Park2012,
abstract = {The atmospheric nitrous oxide concentration has increased by 20{\%} since 1750. Analyses of Antarctic firn and archived air samples reveal seasonal cycles in the isotopic signature of nitrous oxide, which can help to disentangle the contribution of surface sources.},
author = {Park, S. and Croteau, P. and Boering, K. A. and Etheridge, D. M. and Ferretti, D. and Fraser, P. J. and Kim, K-R. and Krummel, P. B. and Langenfelds, R. L. and van Ommen, T. D. and Steele, L. P. and Trudinger, C. M.},
doi = {10.1038/ngeo1421},
issn = {1752-0894},
journal = {Nature Geoscience},
keywords = {Biogeochemistry,Climate sciences},
month = {apr},
number = {4},
pages = {261--265},
publisher = {Nature Publishing Group},
title = {{Trends and seasonal cycles in the isotopic composition of nitrous oxide since 1940}},
url = {http://www.nature.com/articles/ngeo1421},
volume = {5},
year = {2012}
}
@article{Park2019,
abstract = {Climate variations have a profound impact on marine ecosystems and the communities that depend upon them. Anticipating ecosystem shifts using global Earth system models (ESMs) could enable communities to adapt to climate fluctuations and contribute to long-term ecosystem resilience. We show that newly developed ESM-based marine biogeochemical predictions can skillfully predict satellite-derived seasonal to multiannual chlorophyll fluctuations in many regions. Prediction skill arises primarily from successfully simulating the chlorophyll response to the El Ni{\~{n}}o–Southern Oscillation and capturing the winter reemergence of subsurface nutrient anomalies in the extratropics, which subsequently affect spring and summer chlorophyll concentrations. Further investigations suggest that interannual fish-catch variations in selected large marine ecosystems can be anticipated from predicted chlorophyll and sea surface temperature anomalies. This result, together with high predictability for other marine-resource–relevant biogeochemical properties (e.g., oxygen, primary production), suggests a role for ESM-based marine biogeochemical predictions in dynamic marine resource management efforts.},
author = {Park, Jong-Yeon and Stock, Charles A. and Dunne, John P. and Yang, Xiaosong and Rosati, Anthony},
doi = {10.1126/science.aav6634},
issn = {0036-8075},
journal = {Science},
month = {jul},
number = {6450},
pages = {284--288},
title = {{Seasonal to multiannual marine ecosystem prediction with a global Earth system model}},
url = {http://www.sciencemag.org/lookup/doi/10.1126/science.aav6634},
volume = {365},
year = {2019}
}
@article{Partanen2016,
abstract = {Abstract We used an Earth system model of intermediate complexity to study the effects of Solar Radiation Management (SRM) by sea spray geoengineering on ocean biogeochemistry. SRM slightly decreased global ocean net primary productivity (NPP) relative to the control run. The lower temperatures in the SRM run decreased NPP directly but also indirectly increased NPP in some regions due to changes in nutrient availability resulting from changes in ocean stratification and circulation. Reduced light availability had a minor effect on global total NPP but a major regional effect near the nutrient-rich upwelling region off the coast of Peru, where light availability is the main limiting factor for phytoplankton growth in our model. Unused nutrients from regions with decreased NPP also fueled NPP elsewhere. In the context of RCP4.5 simulation used here, SRM decreased ocean carbon uptake due to changes in atmospheric CO2 concentrations, seawater chemistry, NPP, temperature, and ocean circulation.},
author = {Partanen, Antti-Ilari and Keller, David P and Korhonen, Hannele and Matthews, H Damon},
doi = {10.1002/2016GL070111},
journal = {Geophysical Research Letters},
number = {14},
pages = {7600--7608},
title = {{Impacts of sea spray geoengineering on ocean biogeochemistry}},
volume = {43},
year = {2016}
}
@article{Patra2014,
abstract = {The hydroxyl radical (OH) is a key oxidant involved in the removal of air pollutants and greenhouse gases from the atmosphere1,2,3. The ratio of Northern Hemispheric to Southern Hemispheric (NH/SH) OH concentration is important for our understanding of emission estimates of atmospheric species such as nitrogen oxides and methane4,5,6. It remains poorly constrained, however, with a range of estimates from 0.85 to 1.4 (refs 4, 7,8,9,10). Here we determine the NH/SH ratio of OH with the help of methyl chloroform data (a proxy for OH concentrations) and an atmospheric transport model that accurately describes interhemispheric transport and modelled emissions. We find that for the years 2004–2011 the model predicts an annual mean NH–SH gradient of methyl chloroform that is a tight linear function of the modelled NH/SH ratio in annual mean OH. We estimate a NH/SH OH ratio of 0.97 ± 0.12 during this time period by optimizing global total emissions and mean OH abundance to fit methyl chloroform data from two surface-measurement networks and aircraft campaigns11,12,13. Our findings suggest that top-down emission estimates of reactive species such as nitrogen oxides in key emitting countries in the NH that are based on a NH/SH OH ratio larger than 1 may be overestimated.},
author = {Patra, P. K. and Krol, M. C. and Montzka, S. A. and Arnold, T. and Atlas, E. L. and Lintner, B. R. and Stephens, B. B. and Xiang, B. and Elkins, J. W. and Fraser, P. J. and Ghosh, A. and Hintsa, E. J. and Hurst, D. F. and Ishijima, K. and Krummel, P. B. and Miller, B. R. and Miyazaki, K. and Moore, F. L. and M{\"{u}}hle, J. and O'Doherty, S. and Prinn, R. G. and Steele, L. P. and Takigawa, M. and Wang, H. J. and Weiss, R. F. and Wofsy, S. C. and Young, D.},
doi = {10.1038/nature13721},
issn = {0028-0836},
journal = {Nature},
month = {sep},
number = {7517},
pages = {219--223},
title = {{Observational evidence for interhemispheric hydroxyl-radical parity}},
url = {http://www.nature.com/doifinder/10.1038/nature13721},
volume = {513},
year = {2014}
}
@article{Patra2016,
author = {Patra, P.K. and Saeki, T. and Dlugokencky, E.J. and Ishijima, K. and Umezawa, T. and Ito, A. and Aoki, S. and Morimoto, S. and Kort, E.A. and Crotwell, A. and {Ravi Kumar}, K. and Nakazawa, T.},
doi = {10.2151/jmsj.2016-006},
issn = {00261165},
journal = {Journal of the Meteorological Society of Japan. Series II},
number = {1},
pages = {91--113},
publisher = {Meteorological Society of Japan},
title = {{Regional methane emission estimation based on observed atmospheric concentrations (2002–2012)}},
url = {https://www.jstage.jst.go.jp/article/jmsj/94/1/94{\_}2016-006/{\_}article},
volume = {94},
year = {2016}
}
@article{Patra2005a,
abstract = {A Time-dependent inverse (TDI) model is used to estimate carbon dioxide (CO2) fluxes for 64 regions of the globe from atmospheric measurements in the period January 1994 to December 2001. The global land anomalies agree fairly well with earlier results. Large variability in CO2 fluxes are recorded from the land regions, which are typically controlled by the available water for photosynthesis, and air temperature and soil moisture dependent heterotrophic respiration. For example, the anomalous CO2 emissions during the 1997/1998 El Ni{\~{n}}o period are estimated to be about 1.27 ± 0.22, 2.06 ± 0.37, and 1.17 ± 0.20 Pg-C yr-1 from tropical regions in Asia, South America, and Africa, respectively. The CO2 flux anomalies for boreal Asia region are estimated to be 0.83 ± 0.19 and 0.45 ± 0.14 Pg-C yr-1 of CO2 during 1996 and 1998, respectively. Comparison of inversion results with biogeochemical model simulations provide strong evidence that biomass burning (natural and anthropogenic) constitutes the major component in land-atmosphere carbon flux anomalies. The net biosphere-atmosphere carbon exchanges based on the biogeochemical model used in this study are generally lower than those estimated from TDI model results, by about 1.0 Pg-C yr-1 for the periods and regions of intense fire. The correlation and principal component analyses suggest that changes in meteorology (i.e., rainfall and air temperature) associated with the El Ni{\~{n}}o Southern Oscillation are the most dominant controlling factors of CO2 flux anomaly in the tropics, followed by the Indian Ocean Dipole Oscillation. Our results indicate that the Arctic and North Atlantic Oscillations are closely linked with CO2 flux variability in the temperate and high-latitude regions. Copyright 2005 by the American Geophysical Union.},
author = {Patra, Prabir K. and Ishizawa, Misa and Maksyutov, Shamil and Nakazawa, Takakiyo and Inoue, Gen},
doi = {10.1029/2004GB002258},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {sep},
number = {3},
pages = {GB3005},
title = {{Role of biomass burning and climate anomalies for land–atmosphere carbon fluxes based on inverse modeling of atmospheric CO2}},
url = {http://doi.wiley.com/10.1029/2004GB002258},
volume = {19},
year = {2005}
}
@article{Patra2021,
abstract = {Trends and variability in tropospheric hydroxyl (OH) radicals influence budgets of many greenhouse gases, air pollutant species, and ozone depleting substances. Estimations of tropospheric OH trends and variability based on budget analysis of methyl chloroform (CH3CCl3) and process‐based chemistry transport models often produce conflicting results. Here we use a previously tested transport model to simulate atmospheric CH3CCl3 for the period 1985–2018. Based on mismatches between model output and observations, we derive consistent anomalies in the inverse lifetime of CH3CCl3 (KG) using measurements from two independent observational networks (National Oceanic and Atmospheric Administration and Advanced Global Atmospheric Gases Experiment). Our method allows a separation between “physical” (transport, temperature) and “chemical” (i.e., abundance) influences on OH + CH3CCl3 reaction rate in the atmosphere. Small increases in KG due to “physical” influences are mostly driven by increases in the temperature‐dependent reaction between OH and CH3CCl3 and resulted in a smoothly varying increase of 0.80{\%} decade−1. Chemical effects on KG, linked to global changes in OH sources and sinks, show larger year‐to‐year variations (∼2{\%}–3{\%}), and have a negative correlation with the El Ni{\~{n}}o Southern Oscillation. A significant positive trend in KG can be derived after 2001, but it persists only through 2015 and only if we assume that CH3CCl3 emissions decayed more slowly over time than our best estimate suggests. If global CH3CCl3 emissions dropped below 3 Gg year−1 after 2015, recent CH3CCl3 measurements indicate that the 2015–2018 loss rate of CH3CCl3 due to reaction with OH is comparable to its value 2 decades ago.},
author = {Patra, P. K. and Krol, M. C. and Prinn, R. G. and Takigawa, M. and M{\"{u}}hle, J. and Montzka, S. A. and Lal, S. and Yamashita, Y. and Naus, Stijn and Chandra, Naveen and Weiss, R. F. and Krummel, P. B. and Fraser, P. J. and O'Doherty, S. and Elkins, J. W.},
doi = {10.1029/2020JD033862},
issn = {2169-897X},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {patra2021},
month = {dec},
number = {4},
pages = {e2020JD033862.},
title = {{Methyl Chloroform continues to constrain the hydroxyl (OH) variability in the troposphere}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2020JD033862},
volume = {126},
year = {2021}
}
@article{Paulmier2009b,
abstract = {In the modern ocean, oxygen minimum zones (OMZs) are potential traces of a primitive ocean in which Archean bacteria lived and reduced chemical anomalies occurred. But OMZs are also keys to understanding the present unbalanced nitrogen cycle and the oceans' role on atmospheric greenhouse control. OMZs are the main areas of nitrogen loss (as N2, N2O) to the atmosphere through denitrification and anammox, and could even indirectly mitigate the oceanic biological sequestration of CO2. It was recently hypothesized that OMZs are going to spread in the coming decades as a consequence of global climate change. Despite an important OMZ role for the origin of marine life and for the biogeochemical cycles of carbon and nitrogen, there are some key questions on the structure of OMZs at a global scale. There is no agreement concerning the threshold in oxygen that defines an OMZ, and the extent of an OMZ is often evaluated by denitrification criteria which, at the same time, are O2-dependent. Our work deals with the identification of each OMZ, the evaluation of its extent, volume and vertical structure, the determination of its seasonality or permanence and the comparison between OMZs and denitrification zones at a global scale. The co-existence in the OMZ of oxic (in its boundaries) and suboxic (even anoxic, in its core) conditions involves rather complex biogeochemical processes such as strong remineralization of the organic matter, removal of nitrate and release of nitrite. The quantitative OMZ analysis is focused on taking into account the whole water volume under the influence of an OMZ and adapted to the study of the specific low oxygen biogeochemical processes. A characterization of the entire structure for the main and most intense OMZs (O2{\textless}20$\mu$M reaching 1$\mu$M in the core) is proposed based on a previously published CRIO criterion from the eastern South Pacific OMZ and including a large range of O2 concentrations. Using the updated global WOA2005 O2 climatology, the four known tropical OMZs in the open ocean have been described: the Eastern South Pacific and Eastern Tropical North Pacific, in the Pacific Ocean; the Arabian Sea and Bay of Bengal, in the Indian Ocean. Moreover, the Eastern Sub-Tropical North Pacific (25–52°N) has been identified as a lesser known permanent deep OMZ. Two additional seasonal OMZs at high latitude have also been identified: the West Bering Sea and the Gulf of Alaska. The total surface of the permanent OMZs is 30.4 millions of km2 (∼8{\%} of the total oceanic area), and the volume of the OMZ cores (10.3 millions of km3) corresponds to a value ∼7 times higher than previous evaluations. The volume of the OMZ cores is about three times larger than that of the associated denitrification zone, here defined as NMZ (‘nitrate deficit or NDEF{\textgreater}10$\mu$M' maximum zone). The larger OMZ, relative to the extent of denitrification zone, suggests that the unbalanced nitrogen cycle on the global scale could be more intense than previously recognized and that evaluation of the OMZ from denitrification could underestimate their extent.},
author = {Paulmier, A and Ruiz-Pino, D},
doi = {10.1016/j.pocean.2008.08.001},
issn = {00796611},
journal = {Progress in Oceanography},
keywords = {Biogeochemistry,Denitrification,Global ocean,Oxygen,Oxygen minimum zones (OMZs)},
month = {mar},
number = {3-4},
pages = {113--128},
title = {{Oxygen minimum zones (OMZs) in the modern ocean}},
url = {http://www.sciencedirect.com/science/article/pii/S0079661108001468 https://linkinghub.elsevier.com/retrieve/pii/S0079661108001468},
volume = {80},
year = {2009}
}
@article{Paulmier2008,
abstract = {The oxygen minimum zones (OMZs) are recognized as intense sources of N2O greenhouse gas (GHG) and could also be potential sources of CO2, the most important GHG for the present climate change. This study evaluates, for one of the most intense and shallow OMZ, the Chilean East South Pacific OMZ, the simultaneous N2O and CO2 fluxes at the air–sea interface. Four cruises (2000–2002) and 1 year of monitoring (21°–30°–36°S) off Chile allowed the determination of the CO2 and N2O concentrations at the sea surface and the analysis of fluxes variations associated with different OMZ configurations. The Chilean OMZ area can be an intense GHG oceanic local source of both N2O and CO2. The mean N2O fluxes are 5–10 times higher than the maximal previous historical source in an OMZ open area as in the Pacific and Indian Oceans. For CO2, the mean fluxes are also positive and correspond to very high oceanic sources. Even if different coupling and decoupling between N2O and CO2 are observed along the Chilean OMZ, 65{\%} of the situations represent high CO2 and/or N2O sources. The high GHG sources are associated with coastal upwelling transport of OMZ waters rich in N2O and probably also in CO2, located at a shallow depth. The integrated OMZ role on GHG should be better considered to improve our understanding of the past and future atmospheric CO2 and N2O evolutions.},
author = {Paulmier, A. and Ruiz-Pino, D. and Garcon, V.},
doi = {10.1016/j.csr.2008.09.012},
issn = {02784343},
journal = {Continental Shelf Research},
month = {dec},
number = {20},
pages = {2746--2756},
publisher = {Pergamon},
title = {{The oxygen minimum zone (OMZ) off Chile as intense source of CO2 and N2O}},
url = {https://www.sciencedirect.com/science/article/pii/S0278434308003099 https://linkinghub.elsevier.com/retrieve/pii/S0278434308003099},
volume = {28},
year = {2008}
}
@article{Paustian2016,
abstract = {Soils are integral to the function of all terrestrial ecosystems and to food and fibre production. An overlooked aspect of soils is their potential to mitigate greenhouse gas emissions. Although proven practices exist, the implementation of soil-based greenhouse gas mitigation activities are at an early stage and accurately quantifying emissions and reductions remains a substantial challenge. Emerging research and information technology developments provide the potential for a broader inclusion of soils in greenhouse gas policies. Here we highlight ‘state of the art' soil greenhouse gas research, summarize mitigation practices and potentials, identify gaps in data and understanding and suggest ways to close such gaps through new research, technology and collaboration.},
author = {Paustian, Keith and Lehmann, Johannes and Ogle, Stephen and Reay, David and Robertson, G. Philip and Smith, Pete},
doi = {10.1038/nature17174},
issn = {0028-0836},
journal = {Nature},
language = {en},
month = {apr},
number = {7597},
pages = {49--57},
title = {{Climate-smart soils}},
url = {http://dx.doi.org/10.1038/nature17174 http://www.nature.com/doifinder/10.1038/nature17174 http://www.nature.com/articles/nature17174},
volume = {532},
year = {2016}
}
@article{Pavlov2015,
abstract = {This study is based on 20 years of research into the massive dieback of coniferous forests (Pinus sibirica Du Tour, Picea obovata Ledeb., Abies sibirica Ledeb., Pinus sylvestris L., Larix gmelinii (Rupr.) Kuzen., Abies nephrolepis (Trautv. ex Maxim.) Maxim., Pinus koraiensis Siebold {\&} Zucc.) in Siberia and the Far East. It was found that the dieback had been provoked by the causative agents of root rot disease (Armillaria mellea s.l, Heterobasidion annosum s.l, Phellinus sulphurascens Pilat., Porodaedalea niemelaei M. Fischer, Phaeolus schweinitzii (Fr.) Pat.). The disease spread due to the decreased biological sustainability of coniferous trees. A. borealis Marxm. {\&} Korh. should be considered the most dangerous species affecting a large variety of woody plants in different forest-site conditions. The trigger mechanism of the dieback was a combination of adverse climatic anomalies and certain edaphic conditions and/or a set of factors favorable for pathogenic organisms.},
annote = {added by A.Eliseev 25.01.2019},
author = {Pavlov, I N},
doi = {10.1134/S1995425515040125},
issn = {1995-4255},
journal = {Contemporary Problems of Ecology},
month = {jul},
number = {4},
pages = {440--456},
title = {{Biotic and abiotic factors as causes of coniferous forests dieback in Siberia and Far East}},
url = {https://doi.org/10.1134/S1995425515040125 http://link.springer.com/10.1134/S1995425515040125},
volume = {8},
year = {2015}
}
@article{Penuelas2017,
author = {Pe{\~{n}}uelas, Josep and Ciais, Philippe and Canadell, Josep G. and Janssens, Ivan A. and Fern{\'{a}}ndez-Mart{\'{i}}nez, Marcos and Carnicer, Jofre and Obersteiner, Michael and Piao, Shilong and Vautard, Robert and Sardans, Jordi},
doi = {10.1038/s41559-017-0274-8},
issn = {2397-334X},
journal = {Nature Ecology {\&} Evolution},
month = {oct},
number = {10},
pages = {1438--1445},
title = {{Shifting from a fertilization-dominated to a warming-dominated period}},
url = {http://www.nature.com/articles/s41559-017-0274-8},
volume = {1},
year = {2017}
}
@article{Pearson2013,
abstract = {This study shows that climate change could lead to a major redistribution of vegetation across the Arctic, with important implications for biosphere–atmosphere interactions, as well as for biodiversity conservation and ecosystem services. Woody vegetation is predicted to expand substantially over coming decades, causing more Arctic warming through positive climate feedbacks than previously thought.},
author = {Pearson, Richard G and Phillips, Steven J and Loranty, Michael M and Beck, Pieter S A and Damoulas, Theodoros and Knight, Sarah J and Goetz, Scott J},
doi = {10.1038/nclimate1858},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {7},
pages = {673--677},
title = {{Shifts in Arctic vegetation and associated feedbacks under climate change}},
volume = {3},
year = {2013}
}
@article{Pelejero2005,
abstract = {The oceans are becoming more acidic due to absorption of anthropogenic carbon dioxide from the atmosphere. The impact of ocean acidification on marine ecosystems is unclear, but it will likely depend on species adaptability and the rate of change of seawater pH relative to its natural variability. To constrain the natural variability in reef-water pH, we measured boron isotopic compositions in a ∼300-year-old massive Porites coral from the southwestern Pacific. Large variations in pH are found over ∼50-year cycles that covary with the Interdecadal Pacific Oscillation of ocean-atmosphere anomalies, suggesting that natural pH cycles can modulate the impact of ocean acidification on coral reef ecosystems.},
author = {Pelejero, Carles and Calvo, E and McCulloch, M. T. and Marshall, J. F. and Gagan, M. K. and Lough, J. M. and Opdyke, B. N.},
doi = {10.1126/science.1113692},
issn = {0036-8075},
journal = {Science},
month = {sep},
number = {5744},
pages = {2204--2207},
title = {{Preindustrial to Modern Interdecadal Variability in Coral Reef pH}},
url = {http://science.sciencemag.org/content/309/5744/2204.abstract http://www.sciencemag.org/cgi/doi/10.1126/science.1113692},
volume = {309},
year = {2005}
}
@article{Peng2016,
abstract = {Abstract. Methane (CH4) has a 28-fold greater global warming potential than CO2 over 100 years. Atmospheric CH4 concentration has tripled since 1750. Anthropogenic CH4 emissions from China have been growing rapidly in the past decades and contribute more than 10{\%} of global anthropogenic CH4 emissions with large uncertainties in existing global inventories, generally limited to country-scale statistics. To date, a long-term CH4 emission inventory including the major sources sectors and based on province-level emission factors is still lacking. In this study, we produced a detailed annual bottom-up inventory of anthropogenic CH4 emissions from the eight major source sectors in China for the period 1980–2010. In the past 3 decades, the total CH4 emissions increased from 24.4[18.6–30.5]TgCH4yr−1 in 1980 (mean [minimum–maximum of 95{\%} confidence interval]) to 44.9 [36.6–56.4]TgCH4yr−1 in 2010. Most of this increase took place in the 2000s decade with averaged yearly emissions of 38.5 [30.6–48.3]TgCH4yr−1. This fast increase of the total CH4 emissions after 2000 is mainly driven by CH4 emissions from coal exploitation. The largest contribution to total CH4 emissions also shifted from rice cultivation in 1980 to coal exploitation in 2010. The total emissions inferred in this work compare well with the EPA inventory but appear to be 36 and 18{\%} lower than the EDGAR4.2 inventory and the estimates using the same method but IPCC default emission factors, respectively. The uncertainty of our inventory is investigated using emission factors collected from state-of-the-art published literatures. We also distributed province-scale emissions into 0.1° × 0.1° maps using socioeconomic activity data. This new inventory could help understanding CH4 budgets at regional scale and guiding CH4 mitigation policies in China.},
author = {Peng, Shushi and Piao, Shilong and Bousquet, Philippe and Ciais, Philippe and Li, Bengang and Lin, Xin and Tao, Shu and Wang, Zhiping and Zhang, Yuan and Zhou, Feng},
doi = {10.5194/acp-16-14545-2016},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {nov},
number = {22},
pages = {14545--14562},
title = {{Inventory of anthropogenic methane emissions in mainland China from 1980 to 2010}},
url = {https://www.atmos-chem-phys.net/16/14545/2016/},
volume = {16},
year = {2016}
}
@article{Penman2014,
abstract = {The Paleocene-Eocene Thermal Maximum (PETM) has been associated with the release of several thousands of petagrams of carbon (Pg C) as methane and/or carbon dioxide into the ocean-atmosphere system within {\~{}}10 kyr, on the basis of the co-occurrence of a carbon isotope excursion (CIE), widespread dissolution of deep sea carbonates, and global warming. In theory, this rapid carbon release should have severely acidified the surface ocean, though no geochemical evidence has yet been presented. Using boron-based proxies for surface ocean carbonate chemistry, we present the first observational evidence for a drop in the pH of surface and thermocline seawater during the PETM. Planktic foraminifers from a drill site in the North Pacific (Ocean Drilling Program Site 1209) show a {\~{}}0.8‰ decrease in boron isotopic composition ($\delta$ 11 B) at the onset of the event, along with a 30-40{\%} reduction in shell B/Ca. Similar trends in $\delta$ 11 B are present in two lower-resolution records from the South Atlantic and Equatorial Pacific. These observations are consistent with significant, global acidification of the surface ocean lasting at least 70 kyr and requiring sustained carbon release. The anomalies in the B records are consistent with an initial surface pH drop of {\~{}}0.3 units, at the upper range of model-based estimates of acidification.},
author = {Penman, Donald E and H{\"{o}}nisch, B{\"{a}}rbel and Zeebe, Richard E and Thomas, Ellen and Zachos, James C},
doi = {10.1002/2014PA002621},
issn = {08838305},
journal = {Paleoceanography},
month = {may},
number = {5},
pages = {357--369},
title = {{Rapid and sustained surface ocean acidification during the Paleocene–Eocene Thermal Maximum}},
url = {http://doi.wiley.com/10.1002/2014PA002621},
volume = {29},
year = {2014}
}
@article{Peters2011,
abstract = {Nature Climate Change 2, (2011). doi:10.1038/nclimate1332},
author = {Peters, Glen P. and Marland, Gregg and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Boden, Thomas and Canadell, Josep G. and Raupach, Michael R.},
doi = {10.1038/nclimate1332},
isbn = {1758-678X},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jan},
number = {1},
pages = {2--4},
title = {{Rapid growth in CO2 emissions after the 2008–2009 global financial crisis}},
url = {http://www.nature.com/doifinder/10.1038/nclimate1332 http://www.nature.com/articles/nclimate1332},
volume = {2},
year = {2012}
}
@article{Peters2007,
abstract = {We present an estimate of net CO2 exchange between the terrestrial biosphere and the atmosphere across North America for every week in the period 2000 through 2005. This estimate is derived from a set of 28,000 CO2 mole fraction observations in the global atmosphere that are fed into a state-of-the-art data assimilation system for CO2 called CarbonTracker. By design, the surface fluxes produced in CarbonTracker are consistent with the recent history of CO2 in the atmosphere and provide constraints on the net carbon flux independent from national inventories derived from accounting efforts. We find the North American terrestrial biosphere to have absorbed -0.65 PgC/yr (1 petagram = 1015 g; negative signs are used for carbon sinks) averaged over the period studied, partly offsetting the estimated 1.85 PgC/yr release by fossil fuel burning and cement manufacturing. Uncertainty on this estimate is derived from a set of sensitivity experiments and places the sink within a range of -0.4 to -1.0 PgC/yr. The estimated sink is located mainly in the deciduous forests along the East Coast (32{\%}) and the boreal coniferous forests (22{\%}). Terrestrial uptake fell to -0.32 PgC/yr during the large-scale drought of 2002, suggesting sensitivity of the contemporary carbon sinks to climate extremes. CarbonTracker results are in excellent agreement with a wide collection of carbon inventories that form the basis of the first North American State of the Carbon Cycle Report (SOCCR), to be released in 2007. All CarbonTracker results are freely available at http://carbontracker.noaa.gov. {\textcopyright} 2007 by The National Academy of Sciences of the USA.},
author = {Peters, Wouter and Jacobson, Andrew R. and Sweeney, Colm and Andrews, Arlyn E. and Conway, Thomas J. and Masarie, Kenneth and Miller, John B. and Bruhwiler, L. M. P. and Petron, G. and Hirsch, Adam I. and Worthy, D. E. J. and van der Werf, G. R. and Randerson, James T. and Wennberg, Paul O. and Krol, Maarten C. and Tans, Pieter P.},
doi = {10.1073/pnas.0708986104},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Atmospheric composition,Biogeochemistry,Carbon cycle,Data assimilation,Greenhouse gases},
month = {nov},
number = {48},
pages = {18925--18930},
title = {{An atmospheric perspective on North American carbon dioxide exchange: CarbonTracker}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.0708986104},
volume = {104},
year = {2007}
}
@article{Peters2020,
author = {Peters, G. P. and Andrew, R. M. and Canadell, J. G. and Friedlingstein, P and Jackson, R. B. and Korsbakken, J. I. and {Le Qu{\'{e}}r{\'{e}}}, C. and Peregon, A.},
doi = {10.1038/s41558-019-0659-6},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jan},
number = {1},
pages = {3--6},
title = {{Carbon dioxide emissions continue to grow amidst slowly emerging climate policies}},
url = {http://www.nature.com/articles/s41558-019-0659-6},
volume = {10},
year = {2020}
}
@article{Peters2020a,
author = {Peters, Wouter and Bastos, Ana and Ciais, Philippe and Vermeulen, Alex},
doi = {10.1098/rstb.2019.0505},
issn = {0962-8436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
keywords = {Europe,atmosphere,carbon dioxide,drought,photosynthesis,soil moisture},
month = {oct},
number = {1810},
pages = {20190505},
title = {{A historical, geographical and ecological perspective on the 2018 European summer drought}},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2019.0505},
volume = {375},
year = {2020}
}
@article{Peterson2014,
abstract = {Terrestrial carbon storage is dramatically decreased during glacial periods due to cold temperatures, increased aridity, and the presence of large ice sheets on land. Most of the carbon released by the terrestrial biosphere is stored in the ocean, where the light isotopic signature of terrestrial carbon is observed as a 0.32-0.7‰ depletion in benthic foraminiferal $\delta$13C. The wide range in estimated $\delta$13C change results from the use of different subsets of benthic $\delta$13C data and different methods of weighting the mean $\delta$13C by volume. We present a more precise estimate of glacial-interglacial $\delta$13C change of marine dissolved inorganic carbon using benthic Cibicidoides spp. $\delta$13C records from 480 core sites (more than 3 times as many sites as previous studies). We divide the ocean into eight regions to generate linear regressions of regional $\delta$13C versus depth for the Late Holocene (0-6ka) and Last Glacial Maximum (19-23ka) and estimate a mean $\delta$13C decrease of 0.38±0.08‰ (2$\sigma$) for 0.5-5km. Estimating large uncertainty ranges for $\delta$13C change in the top 0.5km, below 5km, and in the Southern Ocean, we calculate a whole-ocean change of 0.34±0.19‰. This implies a terrestrial carbon change that is consistent with recent vegetation model estimates of 330-694 Gt C. Additionally, we find that a well-constrained surface ocean $\delta$13C change is essential for narrowing the uncertainty range of estimated whole-ocean $\delta$13C change. {\textcopyright} 2014 American Geophysical Union.},
author = {Peterson, Carlye D. and Lisiecki, Lorraine E. and Stern, Joseph V.},
doi = {10.1002/2013PA002552},
isbn = {1944-9186},
issn = {08838305},
journal = {Paleoceanography},
keywords = {Holocene,LGM,benthic,carbon isotope,carbon storage change,deglacial},
month = {jun},
number = {6},
pages = {549--563},
title = {{Deglacial whole-ocean $\delta$13C change estimated from 480 benthic foraminiferal records}},
url = {http://doi.wiley.com/10.1002/2013PA002552},
volume = {29},
year = {2014}
}
@article{Petit1999,
abstract = {The recent completion of drilling at Vostok station in East Antarctica has allowed the extension of the ice record of atmospheric composition and climate to the past four glacial–interglacial cycles. The succession of changes through each climate cycle and termination was similar, and atmospheric and climate properties oscillated between stable bounds. Interglacial periods differed in temporal evolution and duration. Atmospheric concentrations of carbon dioxide and methane correlate well with Antarctic air-temperature throughout the record. Present-day atmospheric burdens of these two important greenhouse gases seem to have been unprecedented during the past 420,000 years.},
author = {Petit, J. R. and Jouzel, J. and Raynaud, D. and Barkov, N. I. and Barnola, J.-M. and Basile, I. and Bender, M. and Chappellaz, J. and Davis, M. and Delaygue, G. and Delmotte, M. and Kotlyakov, V. M. and Legrand, M. and Lipenkov, V. Y. and Lorius, C. and P{\'{E}}pin, L. and Ritz, C. and Saltzman, E. and Stievenard, M.},
doi = {10.1038/20859},
issn = {0028-0836},
journal = {Nature},
month = {jun},
number = {6735},
pages = {429--436},
publisher = {Nature Publishing Group},
title = {{Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica}},
url = {http://www.nature.com/doifinder/10.1038/20859 http://www.nature.com/articles/20859},
volume = {399},
year = {1999}
}
@article{Petrenko2017,
author = {Petrenko, Vasilii V and Smith, Andrew M and Schaefer, Hinrich and Riedel, Katja and Brook, Edward and Baggenstos, Daniel and Harth, Christina and Hua, Quan and Buizert, Christo and Schilt, Adrian and Fain, Xavier and Mitchell, Logan and Bauska, Thomas and Orsi, Anais and Weiss, Ray F and Severinghaus, Jeffrey P},
doi = {10.1038/nature23316},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7668},
pages = {443--446},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Minimal geological methane emissions during the Younger Dryas–Preboreal abrupt warming event}},
url = {http://dx.doi.org/10.1038/nature23316 http://10.0.4.14/nature23316 https://www.nature.com/articles/nature23316{\#}supplementary-information http://www.nature.com/articles/nature23316},
volume = {548},
year = {2017}
}
@article{Petrescu2020,
author = {Petrescu, Ana Maria Roxana and Peters, Glen P. and Janssens-Maenhout, Greet and Ciais, Philippe and Tubiello, Francesco N. and Grassi, Giacomo and Nabuurs, Gert-Jan and Leip, Adrian and Carmona-Garcia, Gema and Winiwarter, Wilfried and H{\"{o}}glund-Isaksson, Lena and G{\"{u}}nther, Dirk and Solazzo, Efisio and Kiesow, Anja and Bastos, Ana and Pongratz, Julia and Nabel, Julia E. M. S. and Conchedda, Giulia and Pilli, Roberto and Andrew, Robbie M. and Schelhaas, Mart-Jan and Dolman, Albertus J.},
doi = {10.5194/essd-12-961-2020},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {may},
number = {2},
pages = {961--1001},
title = {{European anthropogenic AFOLU greenhouse gas emissions: a review and benchmark data}},
url = {https://essd.copernicus.org/articles/12/961/2020/},
volume = {12},
year = {2020}
}
@article{Peylin2013,
abstract = {Abstract. Atmospheric CO2 inversions estimate surface carbon fluxes from an optimal fit to atmospheric CO2 measurements, usually including prior constraints on the flux estimates. Eleven sets of carbon flux estimates are compared, generated by different inversions systems that vary in their inversions methods, choice of atmospheric data, transport model and prior information. The inversions were run for at least 5 yr in the period between 1990 and 2010. Mean fluxes for 2001–2004, seasonal cycles, interannual variability and trends are compared for the tropics and northern and southern extra-tropics, and separately for land and ocean. Some continental/basin-scale subdivisions are also considered where the atmospheric network is denser. Four-year mean fluxes are reasonably consistent across inversions at global/latitudinal scale, with a large total (land plus ocean) carbon uptake in the north (−3.4 Pg C yr−1 (±0.5 Pg C yr−1 standard deviation), with slightly more uptake over land than over ocean), a significant although more variable source over the tropics (1.6 ± 0.9 Pg C yr−1) and a compensatory sink of similar magnitude in the south (−1.4 ± 0.5 Pg C yr−1) corresponding mainly to an ocean sink. Largest differences across inversions occur in the balance between tropical land sources and southern land sinks. Interannual variability (IAV) in carbon fluxes is larger for land than ocean regions (standard deviation around 1.06 versus 0.33 Pg C yr−1 for the 1996–2007 period), with much higher consistency among the inversions for the land. While the tropical land explains most of the IAV (standard deviation {\~{}} 0.65 Pg C yr−1), the northern and southern land also contribute (standard deviation {\~{}} 0.39 Pg C yr−1). Most inversions tend to indicate an increase of the northern land carbon uptake from late 1990s to 2008 (around 0.1 Pg C yr−1, predominantly in North Asia. The mean seasonal cycle appears to be well constrained by the atmospheric data over the northern land (at the continental scale), but still highly dependent on the prior flux seasonality over the ocean. Finally we provide recommendations to interpret the regional fluxes, along with the uncertainty estimates.},
author = {Peylin, P. and Law, R. M. and Gurney, K. R. and Chevallier, F. and Jacobson, A. R. and Maki, T. and Niwa, Y. and Patra, P. K. and Peters, W. and Rayner, P. J. and R{\"{o}}denbeck, C. and van der Laan-Luijkx, I. T. and Zhang, X.},
doi = {10.5194/bg-10-6699-2013},
isbn = {1726-4189},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {10},
pages = {6699--6720},
title = {{Global atmospheric carbon budget: results from an ensemble of atmospheric CO2 inversions}},
url = {https://www.biogeosciences.net/10/6699/2013/},
volume = {10},
year = {2013}
}
@article{Pfleiderer2018a,
author = {Pfleiderer, Peter and Schleussner, Carl-Friedrich and Mengel, Matthias and Rogelj, Joeri},
doi = {10.1088/1748-9326/aac319},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jun},
number = {6},
pages = {064015},
publisher = {IOP Publishing},
title = {{Global mean temperature indicators linked to warming levels avoiding climate risks}},
url = {http://stacks.iop.org/1748-9326/13/i=6/a=064015?key=crossref.6ba04aaa6ff0f4ed50547e22fd4f2ad7},
volume = {13},
year = {2018}
}
@article{Pham-Duc2017,
abstract = {AbstractContinental surface water extents and dynamics are key information to model Earth's hydrological and biochemical cycles. This study presents global and regional comparisons between two multisatellite surface water extent datasets, the Global Inundation Extent from Multi-Satellites (GIEMS) and the Surface Water Microwave Product Series (SWAMPS), for the 1993–2007 period, along with two widely used static inundation datasets, the Global Lakes and Wetlands Database (GLWD) and the Matthews and Fung wetland estimates. Maximum surface water extents derived from these datasets are largely different: {\~{}}13 × 106 km2 from GLWD, {\~{}}5.3 × 106 km2 from Matthews and Fung, {\~{}}6.2 × 106 km2 from GIEMS, and {\~{}}10.3 × 106 km2 from SWAMPS. SWAMPS global maximum surface extent reduces by nearly 51{\%} (to {\~{}}5 × 106 km2) when applying a coastal filter, showing a strong contamination in this retrieval over the coastal regions. Anomalous surface waters are also detected with SWAMPS over desert areas. The seasonal amplitude of the ...},
author = {Pham-Duc, Binh and Prigent, Catherine and Aires, Filipe and Papa, Fabrice},
doi = {10.1175/JHM-D-16-0206.1},
issn = {1525-755X},
journal = {Journal of Hydrometeorology},
month = {apr},
number = {4},
pages = {993--1007},
title = {{Comparisons of global terrestrial surface water datasets over 15 years}},
url = {http://journals.ametsoc.org/doi/10.1175/JHM-D-16-0206.1},
volume = {18},
year = {2017}
}
@article{Phillips2009,
author = {Phillips, Oliver L and Aragão, Luiz E. O. C. and Lewis, Simon L and Fisher, Joshua B and Lloyd, Jon and López-González, Gabriela and Malhi, Yadvinder and Monteagudo, Abel and Peacock, Julie and Quesada, Carlos A and van der Heijden, Geertje and Almeida, Samuel and Amaral, Iêda and Arroyo, Luzmila and Aymard, Gerardo and Baker, Tim R and Bánki, Olaf and Blanc, Lilian and Bonal, Damien and Brando, Paulo and Chave, Jerome and de Oliveira, Átila Cristina Alves and Cardozo, Nallaret Dávila and Czimczik, Claudia I and Feldpausch, Ted R and Freitas, Maria Aparecida and Gloor, Emanuel and Higuchi, Niro and Jiménez, Eliana and Lloyd, Gareth and Meir, Patrick and Mendoza, Casimiro and Morel, Alexandra and Neill, David A and Nepstad, Daniel and Patiño, Sandra and Peñuela, Maria Cristina and Prieto, Adriana and Ramírez, Fredy and Schwarz, Michael and Silva, Javier and Silveira, Marcos and Thomas, Anne Sota and ter Steege, Hans and Stropp, Juliana and Vásquez, Rodolfo and Zelazowski, Przemyslaw and Dávila, Esteban Alvarez and Andelman, Sandy and Andrade, Ana and Chao, Kuo-jung and Erwin, Terry and {Di Fiore}, Anthony and C., Eurídice Honorio and Keeling, Helen and Killeen, Tim J and Laurance, William F and Cruz, Antonio Peña and Pitman, Nigel C A and Vargas, Percy Núñez and Ramírez-Angulo, Hirma and Rudas, Agustín and Salamão, Rafael and Silva, Natalino and Terborgh, John and Torres-Lezama, Armando},
doi = {10.1126/science.1164033},
issn = {0036-8075},
journal = {Science},
month = {mar},
number = {5919},
pages = {1344--1347},
title = {{Drought Sensitivity of the Amazon Rainforest}},
url = {https://www.science.org/doi/10.1126/science.1164033},
volume = {323},
year = {2009}
}
@article{Piao2017,
abstract = {Atmospheric CO2 concentration measurements at Barrow, Alaska, together with coupled atmospheric transport and terrestrial ecosystem models show a declining spring net primary productivity response to temperature at high latitudes.},
author = {Piao, Shilong and Liu, Zhuo and Wang, Tao and Peng, Shushi and Ciais, Philippe and Huang, Mengtian and Ahlstrom, Anders and Burkhart, John F. and Chevallier, Fr{\'{e}}d{\'{e}}ric and Janssens, Ivan A. and Jeong, Su-Jong and Lin, Xin and Mao, Jiafu and Miller, John and Mohammat, Anwar and Myneni, Ranga B. and Pe{\~{n}}uelas, Josep and Shi, Xiaoying and Stohl, Andreas and Yao, Yitong and Zhu, Zaichun and Tans, Pieter P.},
doi = {10.1038/nclimate3277},
isbn = {1758-678X},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {may},
number = {5},
pages = {359--363},
title = {{Weakening temperature control on the interannual variations of spring carbon uptake across northern lands}},
url = {http://www.nature.com/articles/nclimate3277},
volume = {7},
year = {2017}
}
@article{Piao2020,
abstract = {With accumulation of carbon cycle observations and model developments over the past decades, exploring interannual variation (IAV) of terrestrial carbon cycle offers the opportunity to better understand climate–carbon cycle relationships. However, despite growing research interest, uncertainties remain on some fundamental issues, such as the contributions of different regions, constituent fluxes and climatic factors to carbon cycle IAV. Here we overviewed the literature on carbon cycle IAV about current understanding of these issues. Observations and models of the carbon cycle unanimously show the dominance of tropical land ecosystems to the signal of global carbon cycle IAV, where tropical semiarid ecosystems contribute as much as the combination of all other tropical ecosystems. Vegetation photosynthesis contributes more than ecosystem respiration to IAV of the global net land carbon flux, but large uncertainties remain on the contribution of fires and other disturbance fluxes. Climatic variations are the major drivers to the IAV of net land carbon flux. Although debate remains on whether the dominant driver is temperature or moisture variability, their interaction,that is, the dependence of carbon cycle sensitivity to temperature on moisture conditions, is emerging as key regulators of the carbon cycle IAV. On timescales from the interannual to the centennial, global carbon cycle variability will be increasingly contributed by northern land ecosystems and oceans. Therefore, both improving Earth system models (ESMs) with the progressive understanding on the fast processes manifested at interannual timescale and expanding carbon cycle observations at broader spatial and longer temporal scales are critical to better prediction on evolution of the carbon–climate system.},
author = {Piao, Shilong and Wang, Xuhui and Wang, Kai and Li, Xiangyi and Bastos, Ana and Canadell, Josep G. and Ciais, Philippe and Friedlingstein, Pierre and Sitch, Stephen},
doi = {10.1111/gcb.14884},
issn = {1354-1013},
journal = {Global Change Biology},
month = {jan},
number = {1},
pages = {300--318},
title = {{Interannual variation of terrestrial carbon cycle: Issues and perspectives}},
url = {https://onlinelibrary.wiley.com/doi/10.1111/gcb.14884},
volume = {26},
year = {2020}
}
@article{Pilcher2019,
abstract = {The Bering Sea is highly vulnerable to ocean acidification (OA) due to naturally cold, poorly buffered waters and ocean mixing processes. Harsh weather conditions within this rapidly changing, geographically remote environment have limited the quantity of carbon chemistry data, thereby hampering efforts to understand underlying spatial-temporal variability and detect long-term trends. We add carbonate chemistry to a regional biogeochemical model of the Bering Sea to explore the underlying mechanisms driving carbon dynamics over a decadal hindcast (2003–2012). The results illustrate that coastal processes generate considerable spatial variability in the biogeochemistry and vulnerability of Bering Sea shelf water to OA. Substantial seasonal biological productivity maintains high supersaturation of aragonite on the outer shelf, whereas riverine freshwater runoff loaded with allochthonous carbon decreases aragonite saturation states ($\Omega$Arag) to values below 1 on the inner shelf. Over the entire 2003–2012 model hindcast, annual surface $\Omega$Arag decreases by 0.025 – 0.04 units/year due to positive trends in the partial pressure of carbon dioxide (pCO2) in surface waters and dissolved inorganic carbon (DIC). Variability in this trend is driven by an increase in fall phytoplankton productivity and shelf carbon uptake, occurring during a transition from a relatively warm (2003–2005) to cold (2010–2012) temperature regime. Our results illustrate how local biogeochemical processes and climate variability can modify projected rates of OA within a coastal shelf system.},
author = {Pilcher, Darren J and Naiman, Danielle M and Cross, Jessica N and Hermann, Albert J and Siedlecki, Samantha A and Gibson, Georgina A and Mathis, Jeremy T},
doi = {10.3389/fmars.2018.00508},
isbn = {2296-7745},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {jan},
pages = {508},
title = {{Modeled Effect of Coastal Biogeochemical Processes, Climate Variability, and Ocean Acidification on Aragonite Saturation State in the Bering Sea}},
volume = {5},
year = {2019}
}
@article{Pison2013,
abstract = {Abstract. Two atmospheric inversions (one fine-resolved and one process-discriminating) and a process-based model for land surface exchanges are brought together to analyse the variations of methane emissions from 1990 to 2009. A focus is put on the role of natural wetlands and on the years 2000–2006, a period of stable atmospheric concentrations. From 1990 to 2000, the top-down and bottom-up visions agree on the time-phasing of global total and wetland emission anomalies. The process-discriminating inversion indicates that wetlands dominate the time-variability of methane emissions (90{\%} of the total variability). The contribution of tropical wetlands to the anomalies is found to be large, especially during the post-Pinatubo years (global negative anomalies with minima between −41 and −19 Tg yr−1 in 1992) and during the alternate 1997–1998 El-Ni{\~{n}}o/1998–1999 La-Ni{\~{n}}a (maximal anomalies in tropical regions between +16 and +22 Tg yr−1 for the inversions and anomalies due to tropical wetlands between +12 and +17 Tg yr−1 for the process-based model). Between 2000 and 2006, during the stagnation of methane concentrations in the atmosphere, the top-down and bottom-up approaches agree on the fact that South America is the main region contributing to anomalies in natural wetland emissions, but they disagree on the sign and magnitude of the flux trend in the Amazon basin. A negative trend (−3.9 ± 1.3 Tg yr−1) is inferred by the process-discriminating inversion whereas a positive trend (+1.3 ± 0.3 Tg yr−1) is found by the process model. Although processed-based models have their own caveats and may not take into account all processes, the positive trend found by the B-U approach is considered more likely because it is a robust feature of the process-based model, consistent with analysed precipitations and the satellite-derived extent of inundated areas. On the contrary, the surface-data based inversions lack constraints for South America. This result suggests the need for a re-interpretation of the large increase found in anthropogenic methane inventories after 2000.},
author = {Pison, I. and Ringeval, B. and Bousquet, P. and Prigent, C. and Papa, F.},
doi = {10.5194/acp-13-11609-2013},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {dec},
number = {23},
pages = {11609--11623},
title = {{Stable atmospheric methane in the 2000s: key-role of emissions from natural wetlands}},
url = {https://www.atmos-chem-phys.net/13/11609/2013/},
volume = {13},
year = {2013}
}
@article{Pitari2014,
abstract = {Emissions of methane (CH4) from oil and natural (O{\&}G) gas operations in the most densely drilled area of the Denver-Julesburg (D-J) Basin in Weld County located in northeastern Colorado are estimated for two days in May 2012 using aircraft-based CH4 observations and planetary boundary layer height and ground-based wind profile measurements. Total top-down CH4 emission estimates are 25.8 ± 8.4 and 26.2 ± 10.7 tonnes CH4/hr for the May 29 and May 31 flights, respectively. Using inventory data, we estimate the total emissions of CH4 from non-O{\&}G gas related sources at 7.1 ± 1.7 and 6.3 ± 1.0 tonnes CH4/hr for these two days. The difference in emissions is attributed to O{\&}G sources in the study region and their total emission is on average 19.3 ± 6.9 tonnes/hr, close to three times higher than an hourly emission estimate based on EPA's Greenhouse Gas Reporting Program data for 2012. We derive top-down emissions estimates for propane, n-butane, i-pentane, n-pentane, and benzene from our total top-down CH4 emission estimate and the relative hydrocarbon abundances in aircraft-based discrete air samples. Emissions for these five non-methane hydrocarbons alone total 25.4 ± 8.2 tonnes/hr. Assuming these emissions are solely originating from O{\&}G related activities in the study region, our results show that the state inventory for total VOC emitted by O{\&}G activities is at least a factor of two too low for May 2012. Our top-down emission estimate of benzene emissions from O{\&}G operations is 173 ± 64 kg/hr, or seven times larger than in the state inventory.},
author = {Pitari, Giovanni and Aquila, Valentina and Kravitz, Ben and Robock, Alan and Watanabe, Shingo and Cionni, Irene and Luca, Natalia De and Genova, Glauco Di and Mancini, Eva and Tilmes, Simone},
doi = {10.1002/2013JD020566},
isbn = {2169-8996},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {mar},
number = {5},
pages = {2629--2653},
pmid = {18563162},
title = {{Stratospheric ozone response to sulfate geoengineering: Results from the Geoengineering Model Intercomparison Project (GeoMIP)}},
url = {http://doi.wiley.com/10.1002/2013JD020566},
volume = {119},
year = {2014}
}
@article{Plazzotta2019,
abstract = {Abstract Solar radiation modification (SRM) is known to strengthen both land and ocean carbon uptake because of its impacts on surface temperature, solar radiation, and other potential drivers of the global carbon cycle. However, the magnitude and timing of the response of both land and ocean carbon uptake to SRM and its consequence on allowable CO2 emissions remain poorly understood. Here we use the results of six Earth system models simulating a continuous stratospheric injection of 5 Tg of sulfur dioxide per year between 2020 and 2069 under the representative concentration pathways 4.5 to investigate the impact of SRM on land and ocean carbon uptake. We find that 50 years of SRM under this protocol increases the allowable CO2 emissions by 40 ± 19 GtC; 85{\%} of this additional uptake of carbon is stored in the land biosphere and 15{\%} in the ocean. This increase in allowable CO2 emissions is however not sustainable after the stoppage of SRM. Earth system models predict a mean release of 8 ± 11 GtC of the carbon back to the atmosphere 20 years after the stoppage which is dominated by large uncertainties in the response of the simulated land carbon cycle to rising temperature and solar radiation. We demonstrate that the time scales of carbon dioxide removal (CDR) potential of SRM are smaller than the time scales of the geological storage assumed in well-established CDR options. This shows that the CDR potential of SRM should be compared to well-established CDR options with caution.},
author = {Plazzotta, Maxime and S{\'{e}}f{\'{e}}rian, Roland and Douville, Herv{\'{e}}},
doi = {10.1029/2019EF001165},
journal = {Earth's Future},
number = {6},
pages = {664--676},
title = {{Impact of solar radiation modification on allowable CO2 emissions: what can we learn from multimodel simulations?}},
volume = {7},
year = {2019}
}
@article{Poeplau2015,
abstract = {A promising option to sequester carbon in agricultural soils is the inclusion of cover crops in cropping systems. The advantage of cover crops as compared to other management practices that increase soil organic carbon (SOC) is that they neither cause a decline in yields, like extensification, nor carbon losses in other systems, like organic manure applications may do. However, the effect of cover crop green manuring on SOC stocks is widely overlooked. We therefore conducted a meta-analysis to derive a carbon response function describing SOC stock changes as a function of time. Data from 139 plots at 37 different sites were compiled. In total, the cover crop treatments had a significantly higher SOC stock than the reference croplands. The time since introduction of cover crops in crop rotations was linearly correlated with SOC stock change (R2=0.19) with an annual change rate of 0.32±0.08Mgha−1yr−1 in a mean soil depth of 22cm and during the observed period of up to 54 years. Elevation above sea level of the plot and sampling depth could be used as explanatory variables to improve the model fit. Assuming that the observed linear SOC accumulation would not proceed indefinitely, we modeled the average SOC stock change with the carbon turnover model RothC. The predicted new steady state was reached after 155 years of cover crop cultivation with a total mean SOC stock accumulation of 16.7±1.5Mgha−1 for a soil depth of 22cm. Thus, the C input driven SOC sequestration with the introduction of cover crops proved to be highly efficient. We estimated a potential global SOC sequestration of 0.12±0.03PgCyr−1, which would compensate for 8{\%} of the direct annual greenhouse gas emissions from agriculture. However, altered N2O emissions and albedo due to cover crop cultivation have not been taken into account here. Data on those processes, which are most likely species-specific, would be needed for reliable greenhouse gas budgets.},
author = {Poeplau, Christopher and Don, Axel},
doi = {10.1016/j.agee.2014.10.024},
issn = {01678809},
journal = {Agriculture, Ecosystems {\&} Environment},
month = {feb},
pages = {33--41},
title = {{Carbon sequestration in agricultural soils via cultivation of cover crops – A meta-analysis}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0167880914004873},
volume = {200},
year = {2015}
}
@article{esd-5-177-2014,
abstract = {Abstract. Reasons for the large uncertainty in land use and land cover change (LULCC) emissions go beyond recognized issues related to the available data on land cover change and the fact that model simulations rely on a simplified and incomplete description of the complexity of biological and LULCC processes. The large range across published LULCC emission estimates is also fundamentally driven by the fact that the net LULCC flux is defined and calculated in different ways across models. We introduce a conceptual framework that allows us to compare the different types of models and simulation setups used to derive land use fluxes. We find that published studies are based on at least nine different definitions of the net LULCC flux. Many multi-model syntheses lack a clear agreement on definition. Our analysis reveals three key processes that are accounted for in different ways: the land use feedback, the loss of additional sink capacity, and legacy (regrowth and decomposition) fluxes. We show that these terminological differences, alone, explain differences between published net LULCC flux estimates that are of the same order as the published estimates themselves. This has consequences for quantifications of the residual terrestrial sink: the spread in estimates caused by terminological differences is conveyed to those of the residual sink. Furthermore, the application of inconsistent definitions of net LULCC flux and residual sink has led to double-counting of fluxes in the past. While the decision to use a specific definition of the net LULCC flux will depend on the scientific application and potential political considerations, our analysis shows that the uncertainty of the net LULCC flux can be substantially reduced when the existing terminological confusion is resolved.},
author = {Pongratz, J and Reick, C H and Houghton, R A and House, J I},
doi = {10.5194/esd-5-177-2014},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {mar},
number = {1},
pages = {177--195},
title = {{Terminology as a key uncertainty in net land use and land cover change carbon flux estimates}},
url = {https://www.earth-syst-dynam.net/5/177/2014/},
volume = {5},
year = {2014}
}
@article{Pongratz2012a,
abstract = {Deflection of sunlight could compensate for the warming induced by increased greenhouse gases. However, the effects of such geoengineering on food security are highly uncertain. Now research using high-carbon-dioxide, geoengineering and control climate simulations suggests that solar-radiation management in a high-carbon-dioxide world generally causes crop yields to increase.},
author = {Pongratz, J and Lobell, D B and Cao, L and Caldeira, K},
doi = {10.1038/nclimate1373},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {2},
pages = {101--105},
title = {{Crop yields in a geoengineered climate}},
url = {https://doi.org/10.1038/nclimate1373},
volume = {2},
year = {2012}
}
@article{Pongratz2018a,
abstract = {As the applications of Earth system models (ESMs) move from general climate pro- jections toward questions of mitigation and adaptation, the inclusion of land man- agement practices in these models becomes crucial. We carried out a survey among modeling groups to show an evolution from models able only to deal with land- cover change to more sophisticated approaches that allow also for the partial inte- gration of land management changes. For the longer term a comprehensive land management representation can be anticipated for all major models. To guide the prioritization of implementation, we evaluate ten land management practices—for- estry harvest, tree species selection, grazing and mowing harvest, crop harvest, crop species selection, irrigation, wetland drainage, fertilization, tillage, and fire—for (1) their importance on the Earth system, (2) the possibility of implementing them in state-of-the-art ESMs, and (3) availability of required input data. Matching these criteria, we identify “low-hanging fruits” for the inclusion in ESMs, such as basic implementations of crop and forestry harvest and fertilization. We also identify research requirements for specific communities to address the remaining land man- agement practices. Data availability severely hampers modeling the most extensive land management practice, grazing and mowing harvest, and is a limiting factor for a comprehensive implementation of most other practices. Inadequate process under- standing hampers even a basic assessment of crop species selection and tillage effects. The need for multiple advanced model structures will be the challenge for a comprehensive implementation of most practices but considerable synergy can be gained using the same structures for different practices. A continuous and closer collaboration of the modeling, Earth observation, and land system science communi- ties is thus required to achieve the inclusion of land management in ESMs.},
author = {Pongratz, Julia and Dolman, Han and Don, Axel and Erb, Karl-Heinz and Fuchs, Richard and Herold, Martin and Jones, Chris and Kuemmerle, Tobias and Luyssaert, Sebastiaan and Meyfroidt, Patrick and Naudts, Kim},
doi = {10.1111/gcb.13988},
issn = {13541013},
journal = {Global Change Biology},
keywords = {Earth observations,Earth system models,climate,croplands,forestry,grazing,land management,land use},
month = {apr},
number = {4},
pages = {1470--1487},
title = {{Models meet data: Challenges and opportunities in implementing land management in Earth system models}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13988 http://doi.wiley.com/10.1111/gcb.13988},
volume = {24},
year = {2018}
}
@article{Poulter2017,
abstract = {Increasing atmospheric methane (CH 4 ) concentrations have contributed to approximately 20{\%} of anthropogenic climate change. Despite the importance of CH 4 as a greenhouse gas, its atmospheric growth rate and dynamics over the past two decades, which include a stabilization period (1999–2006), followed by renewed growth starting in 2007, remain poorly understood. We provide an updated estimate of CH4 emissions from wetlands, the largest natural global CH4 source, for 2000–2012 using an ensemble of biogeochemical models constrained with remote sensing surface inundation and inventory-based wetland area data. Between 2000–2012, boreal wetland CH 4 emissions increased by 1.2 Tg yr −1 (−0.2–3.5 Tg yr −1 ), tropical emissions decreased by 0.9 Tg yr −1 (−3.2−1.1 Tg yr −1 ), yet globally, emissions remained unchanged at 184 ± 22 Tg yr −1 . Changing air temperature was responsible for increasing high-latitude emissions whereas declines in low-latitude wetland area decreased tropical emissions; both dynamics are consistent with features of predicted centennial-scale climate change impacts on wetland CH 4 emissions. Despite uncertainties in wetland area mapping, our study shows that global wetland CH 4 emissions have not contributed significantly to the period of renewed atmospheric CH 4 growth, and is consistent with findings from studies that indicate some combination of increasing fossil fuel and agriculture-related CH 4 emissions, and a decrease in the atmospheric oxidative sink.},
author = {Poulter, Benjamin and Bousquet, Philippe and Canadell, Josep G and Ciais, Philippe and Peregon, Anna and Saunois, Marielle and Arora, Vivek K and Beerling, David J and Brovkin, Victor and Jones, Chris D and Joos, Fortunat and Gedney, Nicola and Ito, Akihito and Kleinen, Thomas and Koven, Charles D and McDonald, Kyle and Melton, Joe R and Peng, Changhui and Peng, Shushi and Prigent, Catherine and Schroeder, Ronny and Riley, William J and Saito, Makoto and Spahni, Renato and Tian, Hanqin and Taylor, Lyla and Viovy, Nicolas and Wilton, David and Wiltshire, Andy and Xu, Xiyan and Zhang, Bowen and Zhang, Zhen and Zhu, Qiuan},
doi = {10.1088/1748-9326/aa8391},
journal = {Environmental Research Letters},
number = {9},
pages = {094013},
title = {{Global wetland contribution to 2000–2012 atmospheric methane growth rate dynamics}},
url = {http://stacks.iop.org/1748-9326/12/i=9/a=094013},
volume = {12},
year = {2017}
}
@article{Poulter2014,
abstract = {The land and ocean act as a sink for fossil-fuel emissions, thereby slowing the rise of atmospheric carbon dioxide concentrations. Although the uptake of carbon by oceanic and terrestrial processes has kept pace with accelerating carbon dioxide emissions until now, atmospheric carbon dioxide concentrations exhibit a large variability on interannual timescales, considered to be driven primarily by terrestrial ecosystem processes dominated by tropical rainforests. We use a terrestrial biogeochemical model, atmospheric carbon dioxide inversion and global carbon budget accounting methods to investigate the evolution of the terrestrial carbon sink over the past 30 years, with a focus on the underlying mechanisms responsible for the exceptionally large land carbon sink reported in 2011 (ref. 2). Here we show that our three terrestrial carbon sink estimates are in good agreement and support the finding of a 2011 record land carbon sink. Surprisingly, we find that the global carbon sink anomaly was driven by growth of semi-arid vegetation in the Southern Hemisphere, with almost 60 per cent of carbon uptake attributed to Australian ecosystems, where prevalent La Nina conditions caused up to six consecutive seasons of increased precipitation. In addition, since 1981, a six per cent expansion of vegetation cover over Australia was associated with a fourfold increase in the sensitivity of continental net carbon uptake to precipitation. Our findings suggest that the higher turnover rates of carbon pools in semi-arid biomes are an increasingly important driver of global carbon cycle inter-annual variability and that tropical rainforests may become less relevant drivers in the future. More research is needed to identify to what extent the carbon stocks accumulated during wet years are vulnerable to rapid decomposition or loss through fire in subsequent years.},
author = {Poulter, Benjamin and Frank, David and Ciais, Philippe and Myneni, Ranga B. and Andela, Niels and Bi, Jian and Broquet, Gregoire and Canadell, Josep G. and Chevallier, Frederic and Liu, Yi Y. and Running, Steven W. and Sitch, Stephen and {Van Der Werf}, Guido R.},
doi = {10.1038/nature13376},
isbn = {1476-4687 (Electronic)$\backslash$r0028-0836 (Linking)},
issn = {14764687},
journal = {Nature},
number = {7502},
pages = {600--603},
pmid = {24847888},
title = {{Contribution of semi-arid ecosystems to interannual variability of the global carbon cycle}},
url = {https://www.nature.com/articles/nature13376},
volume = {509},
year = {2014}
}
@article{Powell2013,
abstract = {Considerable uncertainty surrounds the fate of Amazon rainforests in response to climate change. Here, carbon (C) flux predictions of five terrestrial biosphere models (Community Land Model version 3.5 (CLM3.5), Ecosystem Demography model version 2.1 (ED2), Integrated BIosphere Simulator version 2.6.4 (IBIS), Joint UK Land Environment Simulator version 2.1 (JULES) and Simple Biosphere model version 3 (SiB3)) and a hydrodynamic terrestrial ecosystem model (the Soil–Plant–Atmosphere (SPA) model) were evaluated against measurements from two large‐scale Amazon drought experiments. Model predictions agreed with the observed C fluxes in the control plots of both experiments, but poorly replicated the responses to the drought treatments. Most notably, with the exception of ED2, the models predicted negligible reductions in aboveground biomass in response to the drought treatments, which was in contrast to an observed c. 20{\%} reduction at both sites. For ED2, the timing of the decline in aboveground biomass was accurate, but the magnitude was too high for one site and too low for the other. Three key findings indicate critical areas for future research and model development. First, the models predicted declines in autotrophic respiration under prolonged drought in contrast to measured increases at one of the sites. Secondly, models lacking a phenological response to drought introduced bias in the sensitivity of canopy productivity and respiration to drought. Thirdly, the phenomenological water‐stress functions used by the terrestrial biosphere models to represent the effects of soil moisture on stomatal conductance yielded unrealistic diurnal and seasonal responses to drought.},
author = {Powell, Thomas L and Galbraith, David R and Christoffersen, Bradley O and Harper, Anna and Imbuzeiro, Hewlley M A and Rowland, Lucy and Almeida, Samuel and Brando, Paulo M and da Costa, Antonio Carlos Lola and Costa, Marcos Heil and Levine, Naomi M and Malhi, Yadvinder and Saleska, Scott R and Sotta, Eleneide and Williams, Mathew and Meir, Patrick and Moorcroft, Paul R},
doi = {10.1111/nph.12390},
isbn = {1469-8137},
journal = {New Phytologist},
keywords = {Amazon,carbon cycle,drought,terrestrial biosphe},
number = {2},
pages = {350--365},
title = {{Confronting model predictions of carbon fluxes with measurements of Amazon forests subjected to experimental drought}},
url = {http://dx.doi.org/10.1111/nph.12390},
volume = {200},
year = {2013}
}
@article{Praetorius2015,
abstract = {Marine sediments from the North Pacific document two episodes of expansion and strengthening of the subsurface oxygen minimum zone (OMZ) accompanied by seafloor hypoxia during the last deglacial transition1–4. The mechanisms driving this hypoxia remain under debate1–11. We present a new high-resolution alkenone palaeotemperature reconstruction from the Gulf of Alaska that reveals two abrupt warming events of 4–5 degrees Celsius at the onset of the B{\o}lling and Holocene intervals that coincide with sudden shifts to hypoxia at intermediate depths. The presence of diatomaceous laminations and hypoxia-tolerant benthic foraminiferal species, peaks in redox-sensitive trace metals12,13, and enhanced 15N/14N ratio of organic matter13, collectively suggest association with high export production. A decrease in 18O/16O values of benthic foraminifera accompanying the most severe deoxygenation event indicates subsurface warming of up to about 2 degrees Celsius. We infer that abrupt warming triggered expansion of the North Pacific OMZ through reduced oxygen solubility and increased marine productivity via physiological effects; following initiation of hypoxia, remobilization of iron from hypoxic sediments could have provided a positive feedback on ocean deoxygenation through increased nutrient utilization and carbon export. Such a biogeochemical amplification process implies high sensitivity of OMZ expansion to warming.},
author = {Praetorius, S. K. and Mix, A. C. and Walczak, M. H. and Wolhowe, M. D. and Addison, J. A. and Prahl, F. G.},
doi = {10.1038/nature15753},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {nov},
number = {7578},
pages = {362--366},
pmid = {26581293},
title = {{North Pacific deglacial hypoxic events linked to abrupt ocean warming}},
url = {http://www.nature.com/articles/nature15753},
volume = {527},
year = {2015}
}
@article{Prather2015,
abstract = {The lifetime of nitrous oxide, the third‐most‐important human‐emitted greenhouse gas, is based to date primarily on model studies or scaling to other gases. This work calculates a semiempirical lifetime based on Microwave Limb Sounder satellite measurements of stratospheric profiles of nitrous oxide, ozone, and temperature; laboratory cross‐section data for ozone and molecular oxygen plus kinetics for O(1D); the observed solar spectrum; and a simple radiative transfer model. The result is 116 ± 9 years. The observed monthly‐to‐biennial variations in lifetime and tropical abundance are well matched by four independent chemistry‐transport models driven by reanalysis meteorological fields for the period of observation (2005–2010), but all these models overestimate the lifetime due to lower abundances in the critical loss region near 32 km in the tropics. These models plus a chemistry‐climate model agree on the nitrous oxide feedback factor on its own lifetime of 0.94 ± 0.01, giving N2O perturbations an effective residence time of 109 years. Combining this new empirical lifetime with model estimates of residence time and preindustrial lifetime (123 years) adjusts our best estimates of the human‐natural balance of emissions today and improves the accuracy of projected nitrous oxide increases over this century.},
author = {Prather, Michael J. and Hsu, Juno and DeLuca, Nicole M. and Jackman, Charles H. and Oman, Luke D. and Douglass, Anne R. and Fleming, Eric L. and Strahan, Susan E. and Steenrod, Stephen D. and S{\o}vde, O. Amund and Isaksen, Ivar S. A. and Froidevaux, Lucien and Funke, Bernd},
doi = {10.1002/2015JD023267},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jun},
number = {11},
pages = {5693--5705},
publisher = {Wiley-Blackwell},
title = {{Measuring and modeling the lifetime of nitrous oxide including its variability}},
url = {http://doi.wiley.com/10.1002/2015JD023267},
volume = {120},
year = {2015}
}
@article{Prather2012,
author = {Prather, Michael J. and Holmes, Christopher D. and Hsu, Juno},
doi = {10.1029/2012GL051440},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {may},
number = {9},
pages = {L09803},
title = {{Reactive greenhouse gas scenarios: Systematic exploration of uncertainties and the role of atmospheric chemistry}},
url = {http://doi.wiley.com/10.1029/2012GL051440},
volume = {39},
year = {2012}
}
@article{Prinn2000,
author = {Prinn, R. G. and Weiss, R. F. and Fraser, P. J. and Simmonds, P. G. and Cunnold, D. M. and Alyea, F. N. and O'Doherty, S. and Salameh, P. and Miller, B. R. and Huang, J. and Wang, R. H. J. and Hartley, D. E. and Harth, C. and Steele, L. P. and Sturrock, G. and Midgley, P. M. and McCulloch, A.},
doi = {10.1029/2000JD900141},
issn = {01480227},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {doi:10.1029/2000JD900141,http://dx.doi.org/10.1029/2000JD900141},
month = {jul},
number = {D14},
pages = {17751--17792},
title = {{A history of chemically and radiatively important gases in air deduced from ALE/GAGE/AGAGE}},
url = {http://doi.wiley.com/10.1029/2000JD900141},
volume = {105},
year = {2000}
}
@article{Prinn2016,
author = {Prinn, Ronald G. and Weiss, Ray F. and Arduini, Jgor and Arnold, Tim and DeWitt, H. Langley and Fraser, Paul J. and Ganesan, Anita L. and Gasore, Jimmy and Harth, Christina M. and Hermansen, Ove and Kim, Jooil and Krummel, Paul B. and Li, Shanlan and Loh, Zo{\"{e}} M. and Lunder, Chris R. and Maione, Michela and Manning, Alistair J. and Miller, Ben R. and Mitrevski, Blagoj and M{\"{u}}hle, Jens and O'Doherty, Simon and Park, Sunyoung and Reimann, Stefan and Rigby, Matt and Saito, Takuya and Salameh, Peter K. and Schmidt, Roland and Simmonds, Peter G. and Steele, L. Paul and Vollmer, Martin K. and Wang, Ray H. and Yao, Bo and Yokouchi, Yoko and Young, Dickon and Zhou, Lingxi},
doi = {10.5194/essd-10-985-2018},
institution = {Carbon Dioxide Information Analysis Center (CDIAC), Oak Ridge National Laboratory (ORNL), U.S. Department of Energy (DOE).},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {jun},
number = {2},
pages = {985--1018},
title = {{History of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gases Experiment (AGAGE)}},
url = {https://essd.copernicus.org/articles/10/985/2018/},
volume = {10},
year = {2018}
}
@article{Proctor2018,
abstract = {Solar radiation management is increasingly considered to be an option for managing global temperatures 1,2 , yet the economic effects of ameliorating climatic changes by scattering sunlight back to space remain largely unknown 3. Although solar radiation management may increase crop yields by reducing heat stress 4 , the effects of concomitant changes in available sunlight have never been empirically estimated. Here we use the volcanic eruptions that inspired modern solar radiation management proposals as natural experiments to provide the first estimates, to our knowledge, of how the stratospheric sulfate aerosols created by the eruptions of El Chich{\'{o}}n and Mount Pinatubo altered the quantity and quality of global sunlight, and how these changes in sunlight affected global crop yields. We find that the sunlight-mediated effect of stratospheric sulfate aerosols on yields is negative for both C4 (maize) and C3 (soy, rice and wheat) crops. Applying our yield model to a solar radiation management scenario based on stratospheric sulfate aerosols, we find that projected mid-twenty-first century damages due to scattering sunlight caused by solar radiation management are roughly equal in magnitude to benefits from cooling. This suggests that solar radiation management-if deployed using stratospheric sulfate aerosols similar to those emitted by the volcanic eruptions it seeks to mimic-would, on net, attenuate little of the global agricultural damage from climate change. Our approach could be extended to study the effects of solar radiation management on other global systems, such as human health or ecosystem function. Geoengineering-the purposeful alteration of the climate to offset changes induced by greenhouse gas emissions-is a proposed, but still poorly understood, approach to limit future warming 5. One of the most widely suggested geoengineering strategies is solar radiation management (SRM). SRM proposals typically involve spraying precursors to sulfate aerosols into the stratosphere to produce particles that cool the earth by reflecting sunlight back into space 6. The closest natural analogues to these SRM proposals are major volcanic eruptions 7. Eruptions of El Chich{\'{o}}n (1982, Mexico) and Mount Pinatubo (1991, the Philippines) injected 7 and 20 Mt of sulfur dioxide, respectively, into the atmosphere, which was then oxidized to form stratospheric sulfate aerosols (SSAs) 8. These particles propagated throughout the tropics over several weeks and spread la{\ldots}},
author = {Proctor, Jonathan and Hsiang, Solomon and Burney, Jennifer and Burke, Marshall and Schlenker, Wolfram},
doi = {10.1038/s41586-018-0417-3},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7719},
pages = {480--483},
publisher = {Springer US},
title = {{Estimating global agricultural effects of geoengineering using volcanic eruptions}},
url = {http://www.nature.com/articles/s41586-018-0417-3},
volume = {560},
year = {2018}
}
@article{Prokopiou2017,
abstract = {Abstract. N2O is currently the third most important anthropogenic greenhouse gas in terms of radiative forcing and its atmospheric mole fraction is rising steadily. To quantify the growth rate and its causes over the past decades, we performed a multi-site reconstruction of the atmospheric N2O mole fraction and isotopic composition using new and previously published firn air data collected from Greenland and Antarctica in combination with a firn diffusion and densification model. The multi-site reconstruction showed that while the global mean N2O mole fraction increased from (290±1)nmolmol−1 in 1940 to (322±1)nmolmol−1 in 2008, the isotopic composition of atmospheric N2O decreased by (−2.2±0.2)‰ for $\delta$15Nav, (−1.0±0.3)‰ for $\delta$18O, (−1.3±0.6)‰ for $\delta$15N$\alpha$, and (−2.8±0.6)‰ for $\delta$15N$\beta$ over the same period. The detailed temporal evolution of the mole fraction and isotopic composition derived from the firn air model was then used in a two-box atmospheric model (comprising a stratospheric box and a tropospheric box) to infer changes in the isotopic source signature over time. The precise value of the source strength depends on the choice of the N2O lifetime, which we choose to fix at 123 years. The average isotopic composition over the investigated period is $\delta$15Nav = (−7.6±0.8)‰ (vs. air-N2), $\delta$18O = (32.2±0.2)‰ (vs. Vienna Standard Mean Ocean Water – VSMOW) for $\delta$18O, $\delta$15N$\alpha$ = (−3.0±1.9)‰ and $\delta$15N$\beta$ = (−11.7±2.3)‰. $\delta$15Nav, and $\delta$15N$\beta$ show some temporal variability, while for the other signatures the error bars of the reconstruction are too large to retrieve reliable temporal changes. Possible processes that may explain trends in 15N are discussed. The 15N site preference ( = $\delta$15N$\alpha$ − $\delta$15N$\beta$) provides evidence of a shift in emissions from denitrification to nitrification, although the uncertainty envelopes are large.},
author = {Prokopiou, Markella and Martinerie, Patricia and Sapart, C{\'{e}}lia J. and Witrant, Emmanuel and Monteil, Guillaume and Ishijima, Kentaro and Bernard, Sophie and Kaiser, Jan and Levin, Ingeborg and Blunier, Thomas and Etheridge, David and Dlugokencky, Ed and van de Wal, Roderik S. W. and R{\"{o}}ckmann, Thomas},
doi = {10.5194/acp-17-4539-2017},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {apr},
number = {7},
pages = {4539--4564},
title = {{Constraining N2O emissions since 1940 using firn air isotope measurements in both hemispheres}},
url = {https://www.atmos-chem-phys.net/17/4539/2017/},
volume = {17},
year = {2017}
}
@article{Prokopiou2018,
author = {Prokopiou, M. and Sapart, C. J. and Rosen, J. and Sperlich, P. and Blunier, T. and Brook, E. and van de Wal, R. S. W. and R{\"{o}}ckmann, T.},
doi = {10.1029/2018JD029008},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {sep},
number = {18},
pages = {10757--10773},
title = {{Changes in the Isotopic Signature of Atmospheric Nitrous Oxide and Its Global Average Source During the Last Three Millennia}},
url = {http://doi.wiley.com/10.1029/2018JD029008},
volume = {123},
year = {2018}
}
@article{Pugh2019,
abstract = {Although the existence of a large carbon sink in terrestrial ecosystems is well-established, the drivers of this sink remain uncertain. It has been suggested that perturbations to forest demography caused by past land-use change, management, and natural disturbances may be causing a large component of current carbon uptake. Here we use a global compilation of forest age observations, combined with a terrestrial biosphere model with explicit modeling of forest regrowth, to partition the global forest carbon sink between old-growth and regrowth stands over the period 1981–2010. For 2001–2010 we find a carbon sink of 0.85 (0.66–0.96) Pg year −1 located in intact old-growth forest, primarily in the moist tropics and boreal Siberia, and 1.30 (1.03–1.96) Pg year −1 located in stands regrowing after past disturbance. Approaching half of the sink in regrowth stands would have occurred from demographic changes alone, in the absence of other environmental changes. These age-constrained results show consistency with those simulated using an ensemble of demographically-enabled terrestrial biosphere models following an independent reconstruction of historical land use and management. We estimate that forests will accumulate an additional 69 (44–131) Pg C in live biomass from changes in demography alone if natural disturbances, wood harvest, and reforestation continue at rates comparable to those during 1981–2010. Our results confirm that it is not possible to understand the current global terrestrial carbon sink without accounting for the sizeable sink due to forest demography. They also imply that a large portion of the current terrestrial carbon sink is strictly transient in nature.},
author = {Pugh, Thomas A M and Lindeskog, Mats and Smith, Benjamin and Poulter, Benjamin and Arneth, Almut and Haverd, Vanessa and Calle, Leonardo},
doi = {10.1073/pnas.1810512116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {mar},
number = {10},
pages = {4382--4387},
title = {{Role of forest regrowth in global carbon sink dynamics}},
url = {https://www.pnas.org/content/pnas/116/10/4382.full.pdf http://www.pnas.org/lookup/doi/10.1073/pnas.1810512116},
volume = {116},
year = {2019}
}
@article{Pugh2018a,
abstract = {Abstract The terrestrial biosphere shows substantial inertia in its response to environmental change. Hence, assessments of transient changes in ecosystem properties to 2100 do not capture the full magnitude of the response realized once ecosystems reach an effective equilibrium with the changed environmental boundary conditions. This equilibrium state can be termed the committed state, in contrast to a transient state in which the ecosystem is in disequilibrium. The difference in ecosystem properties between the transient and committed states represents the committed change yet to be realized. Here an ensemble of dynamic global vegetation model simulations was used to assess the changes in tree cover and carbon storage for a variety of committed states, relative to a preindustrial baseline, and to attribute the drivers of uncertainty. Using a subset of simulations, the committed changes in these variables post-2100, assuming climate stabilization, were calculated. The results show large committed changes in tree cover and carbon storage, with model disparities driven by residence time in the tropics, and residence time and productivity in the boreal. Large changes remain ongoing well beyond the end of the 21st century. In boreal ecosystems, the simulated increase in vegetation carbon storage above preindustrial levels was 20?95 Pg C at 2 K of warming, and 45?201 Pg C at 5 K, of which 38?155 Pg C was due to expansion in tree cover. Reducing the large uncertainties in long-term commitment and rate-of-change of terrestrial carbon uptake will be crucial for assessments of emissions budgets consistent with limiting climate change.},
annote = {From Duplicate 2 (A large committed long-term sink of carbon due to vegetation dynamics - Pugh, T A M; Jones, C D; Huntingford, C; Burton, C; Arneth, A; Brovkin, V; Ciais, P; Lomas, M; Robertson, E; Piao, S L; Sitch, S)

From Duplicate 1 (A Large Committed Long-Term Sink of Carbon due to Vegetation Dynamics - Pugh, T A M; Jones, C D; Huntingford, C; Burton, C; Arneth, A; Brovkin, V; Ciais, P; Lomas, M; Robertson, E; Piao, S L; Sitch, S)

doi: 10.1029/2018EF000935

From Duplicate 3 (A Large Committed Long-Term Sink of Carbon due to Vegetation Dynamics - Pugh, T A M; Jones, C D; Huntingford, C; Burton, C; Arneth, A; Brovkin, V; Ciais, P; Lomas, M; Robertson, E; Piao, S L; Sitch, S)

doi: 10.1029/2018EF000935},
author = {Pugh, T A M and Jones, C D and Huntingford, C and Burton, C and Arneth, A and Brovkin, V and Ciais, P and Lomas, M and Robertson, E and Piao, S L and Sitch, S},
doi = {10.1029/2018EF000935},
issn = {23284277},
journal = {Earth's Future},
keywords = {DGVM,ESM,carbon cycling,committed sink,vegetation},
month = {oct},
number = {10},
pages = {1413--1432},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{A Large Committed Long-Term Sink of Carbon due to Vegetation Dynamics}},
url = {https://doi.org/10.1029/2018EF000935 http://doi.wiley.com/10.1029/2018EF000935},
volume = {6},
year = {2018}
}
@article{Qi2017,
abstract = {The uptake of anthropogenic CO2 by the ocean decreases seawater pH and carbonate mineral aragonite saturation state ($\Omega$arag), a process known as Ocean Acidification (OA). This can be detrimental to marine organisms and ecosystems. The Arctic Ocean is particularly sensitive to climate change and aragonite is expected to become undersaturated ($\Omega$arag {\textless} 1) there sooner than in other oceans. However, the extent and expansion rate of OA in this region are still unknown. Here we show that, between the 1990s and 2010, low $\Omega$arag waters have expanded northwards at least 5°, to 85° N, and deepened 100 m, to 250 m depth. Data from trans-western Arctic Ocean cruises show that $\Omega$arag {\textless} 1 water has increased in the upper 250 m from 5{\%} to 31{\%} of the total area north of 70° N. Tracer data and model simulations suggest that increased Pacific Winter Water transport, driven by an anomalous circulation pattern and sea-ice retreat, is primarily responsible for the expansion, although local carbon recycling and anthropogenic CO2 uptake have also contributed. These results indicate more rapid acidification is occurring in the Arctic Ocean than the Pacific and Atlantic oceans, with the western Arctic Ocean the first open-ocean region with large-scale expansion of acidified' water directly observed in the upper water column. {\textcopyright} 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
author = {Qi, Di and Chen, Liqi and Chen, Baoshan and Gao, Zhongyong and Zhong, Wenli and Feely, Richard A. and Anderson, Leif G. and Sun, Heng and Chen, Jianfang and Chen, Min and Zhan, Liyang and Zhang, Yuanhui and Cai, Wei-Jun},
doi = {10.1038/nclimate3228},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {mar},
number = {3},
pages = {195--199},
publisher = {Nature Publishing Group},
title = {{Increase in acidifying water in the western Arctic Ocean}},
url = {http://www.nature.com/articles/nclimate3228},
volume = {7},
year = {2017}
}
@article{Qi2020,
abstract = {To better understand the extent of acidification in the Arctic Ocean, we present pH measurements collected along a shelf-slope-basin transect from the Chukchi Sea shelf to the Chukchi Abyssal Plain (CAP) in the western Arctic Ocean during the summer 2010 Chinese Arctic National Research Expedition (CHINARE) cruise. We observed low pH values in the Chukchi Sea shelf bottom waters ({\~{}}30 m-bottom) and CAP upper haloline layer (UHL) (100–200 m). In the shelf bottom waters, the pH values were 7.66–8.13, about 0.07–0.68 pH units lower than the surface values of 8.20–8.24. In the CAP subsurface waters, the pH values were 7.85–7.98, about 0.08–0.31 pH units lower than the surface values of 8.20–8.24. Biogeochemical model simulations suggest that remineralized CO2 driven by sea-ice loss is primarily responsible for the low pH values in the bottom waters of the Chukchi Sea (shelf) and the UHL waters of the CAP (basin). Recent sea-ice melt enhanced organic matter production in surface waters and subsequent supported the increased microbial respiration of organic matter in bottom waters. Moreover, low pH bottom waters were flushed into the UHL during winter to sustain the low pH characteristics in the subsurface basin layers. In addition, our simplified model suggests that the thermodynamic effect of pH is small. However, increasing temperature significantly increased aragonite saturation ($\Omega$arag) which slowed down the speed of acidification.},
author = {Qi, Di and Chen, Baoshan and Chen, Liqi and Lin, Hongmei and Gao, Zhongyong and Sun, Hen and Zhang, Yuanhui and Sun, Xiuwu and Cai, Weijun},
doi = {https://doi.org/10.1016/j.polar.2020.100504},
issn = {1873-9652},
journal = {Polar Science},
keywords = {Acidification,Arctic ocean,Sea-ice loss,pH},
pages = {100504},
title = {{Coastal acidification induced by biogeochemical processes driven by sea-ice melt in the western Arctic ocean}},
url = {http://www.sciencedirect.com/science/article/pii/S1873965220300025},
volume = {23},
year = {2020}
}
@article{Qian2017,
abstract = {The East China Sea (ECS) off the Changjiang (Yangtze River) Estuary, located around the near field of the Changjiang plume (CJP) is a hot spot where phytoplankton blooms in the surface water and hypoxias in the subsurface/bottom waters are frequently observed. Based on field observations conducted in summer 2009 and 2011, we examined non-local drivers associated with the initial dissolved oxygen (DO) levels that had significant impact on the development of summer hypoxias in the ECS off the Changjiang Estuary. The bottom water mass therein could be traced isopycnally at 24.2 {\textless} $\sigma$$\theta$ {\textless} 25.2 back to the vicinity of the Luzon Strait, ∼1300 km upstream, where subsurface Kuroshio water (∼220 m deep with ∼190 $\mu$mol DO kg−1) mixed with the South China Sea subsurface water (∼120 m deep with ∼130 $\mu$mol DO kg−1). Owing to the difference in DO of these two source water masses, their mixing ratio ultimately determined the initial DO supply to the ECS bottom water that eventually reached the hypoxic zone. This water mass mixture was also subject to biogeochemical alteration during its travel (∼60 days) after it intruded into the ECS at the northeastern tip of Taiwan. Along the pathway of the intruded bottom-hugging water, we found systematic increases in nutrient concentrations and apparent oxygen utilization, or drawdown in DO following Redfield stoichiometry as a result of marine organic matter decomposition. These non-local factors exerted a synergistic control on the initial DO of CJP bottom water promoting hypoxia formation, although the residence time of the CJP bottom water was relatively short (∼11 days). We contend that such far field drivers should be taken into account in order to better predict the future scenarios of coastal hypoxias in the context of global warming.},
author = {Qian, Wei and Dai, Minhan and Xu, Min and Kao, Shuh-ji and Du, Chuanjun and Liu, Jinwen and Wang, Hongjie and Guo, Liguo and Wang, Lifang},
doi = {10.1016/j.ecss.2016.08.032},
issn = {02727714},
journal = {Estuarine, Coastal and Shelf Science},
month = {nov},
pages = {393--399},
publisher = {Academic Press},
title = {{Non-local drivers of the summer hypoxia in the East China Sea off the Changjiang Estuary}},
url = {https://www.sciencedirect.com/science/article/pii/S0272771416302876 https://linkinghub.elsevier.com/retrieve/pii/S0272771416302876},
volume = {198},
year = {2017}
}
@article{Qiu2013,
abstract = {AbstractBeing the extension of a wind-driven western boundary current, the Kuroshio Extension (KE) has long been recognized as a turbulent current system rich in large-amplitude meanders and energetic pinched-off eddies. An important feature emerging from recent satellite altimeter measurements and eddy-resolving ocean model simulations is that the KE system exhibits well-defined decadal modulations between a stable and an unstable dynamic state. Here the authors show that the decadally modulating KE dynamic state can be effectively defined by the sea surface height (SSH) anomalies in the 31°?36°N, 140°?165°E region. By utilizing the SSH-based KE index from 1977 to 2012, they demonstrate that the time-varying KE dynamic state can be predicted at lead times of up to {\~{}}6 yr. This long-term predictability rests on two dynamic processes: 1) the oceanic adjustment is via baroclinic Rossby waves that carry interior wind-forced anomalies westward into the KE region and 2) the low-frequency KE variability influences the extratropical storm tracks and surface wind stress curl field across the North Pacific basin. By shifting poleward (equatorward) the storm tracks and the large-scale wind stress curl pattern during its stable (unstable) dynamic state, the KE variability induces a delayed negative feedback that can enhance the predictable SSH variance on the decadal time scales.},
annote = {doi: 10.1175/JCLI-D-13-00318.1},
author = {Qiu, Bo and Chen, Shuiming and Schneider, Niklas and Taguchi, Bunmei},
doi = {10.1175/JCLI-D-13-00318.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {nov},
number = {4},
pages = {1751--1764},
publisher = {American Meteorological Society},
title = {{A Coupled Decadal Prediction of the Dynamic State of the Kuroshio Extension System}},
url = {https://doi.org/10.1175/JCLI-D-13-00318.1},
volume = {27},
year = {2013}
}
@article{Rodenbeck2015,
abstract = {Abstract. Using measurements of the surface-ocean CO2 partial pressure (pCO2) and 14 different pCO2 mapping methods recently collated by the Surface Ocean pCO2 Mapping intercomparison (SOCOM) initiative, variations in regional and global sea–air CO2 fluxes are investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCO2 seasonality, in line with previous estimates. In terms of interannual variability (IAV), all mapping methods estimate the largest variations to occur in the eastern equatorial Pacific. Despite considerable spread in the detailed variations, mapping methods that fit the data more closely also tend to agree more closely with each other in regional averages. Encouragingly, this includes mapping methods belonging to complementary types – taking variability either directly from the pCO2 data or indirectly from driver data via regression. From a weighted ensemble average, we find an IAV amplitude of the global sea–air CO2 flux of 0.31 PgC yr−1 (standard deviation over 1992–2009), which is larger than simulated by biogeochemical process models. From a decadal perspective, the global ocean CO2 uptake is estimated to have gradually increased since about 2000, with little decadal change prior to that. The weighted mean net global ocean CO2 sink estimated by the SOCOM ensemble is −1.75 PgC yr−1 (1992–2009), consistent within uncertainties with estimates from ocean-interior carbon data or atmospheric oxygen trends.},
author = {R{\"{o}}denbeck, C and Bakker, D C E and Gruber, N and Iida, Y and Jacobson, A R and Jones, S and Landsch{\"{u}}tzer, P and Metzl, N and Nakaoka, S and Olsen, A and Park, G.-H. and Peylin, P and Rodgers, K B and Sasse, T P and Schuster, U and Shutler, J D and Valsala, V and Wanninkhof, R and Zeng, J},
doi = {10.5194/bg-12-7251-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {dec},
number = {23},
pages = {7251--7278},
title = {{Data-based estimates of the ocean carbon sink variability – first results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM)}},
url = {https://www.biogeosciences.net/12/7251/2015/},
volume = {12},
year = {2015}
}
@article{Rodenbeck2014,
abstract = {Abstract. Interannual anomalies in the sea–air carbon dioxide (CO2) exchange have been estimated from surface-ocean CO2 partial pressure measurements. Available data are sufficient to constrain these anomalies in large parts of the tropical and North Pacific and in the North Atlantic, in some areas covering the period from the mid 1980s to 2011. Global interannual variability is estimated as about 0.31 Pg C yr−1 (temporal standard deviation 1993–2008). The tropical Pacific accounts for a large fraction of this global variability, closely tied to El Ni{\~{n}}o–Southern Oscillation (ENSO). Anomalies occur more than 6 months later in the east than in the west. The estimated amplitude and ENSO response are roughly consistent with independent information from atmospheric oxygen data. This both supports the variability estimated from surface-ocean carbon data and demonstrates the potential of the atmospheric oxygen signal to constrain ocean biogeochemical processes. The ocean variability estimated from surface-ocean carbon data can be used to improve land CO2 flux estimates from atmospheric inversions.},
author = {R{\"{o}}denbeck, C. and Bakker, D. C. E. and Metzl, N. and Olsen, A. and Sabine, C. and Cassar, N. and Reum, F. and Keeling, R. F. and Heimann, M.},
doi = {10.5194/bg-11-4599-2014},
issn = {1726-4189},
journal = {Biogeosciences},
month = {sep},
number = {17},
pages = {4599--4613},
title = {{Interannual sea–air CO2 flux variability from an observation-driven ocean mixed-layer scheme}},
url = {https://www.biogeosciences.net/11/4599/2014/},
volume = {11},
year = {2014}
}
@article{Rodenbeck2018,
abstract = {One contribution of 22 to a discussion meeting issue 'The impact of the 2015/2016 El Ni{\~{n}}o on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'. Subject Areas: environmental science Interannual variations in the large-scale net ecosystem exchange (NEE) of CO 2 between the terrestrial biosphere and the atmosphere were estimated for 1957-2017 from sustained measurements of atmospheric CO 2 mixing ratios. As the observations are sparse in the early decades, available records were combined into a 'quasi-homogeneous' dataset based on similarity in their signals, to minimize spurious variations from beginning or ending data records. During El Ni{\~{n}} o events, CO 2 is anomalously released from the tropical band, and a few months later also in the northern extratropical band. This behaviour can approximately be represented by a linear relationship of the NEE anomalies and local air temperature anomalies, with sensitivity coefficients depending on geographical location and season. The apparent climate sensitivity of global total NEE against variations in pan-tropically averaged annual air temperature slowly changed over time during the 1957-2017 period, first increasing (though less strongly than in previous studies) but then decreasing again. However, only part of this change can be attributed to actual changes in local physiological or ecosystem processes, the rest probably arising from shifts in the geographical area of dominating temperature variations. This article is part of a discussion meeting issue 'The impact of the 2015/2016 El Ni{\~{n}} o on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.},
author = {R{\"{o}}denbeck, C. and Zaehle, S. and Keeling, R. and Heimann, M.},
doi = {10.1098/rstb.2017.0303},
issn = {0962-8436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
keywords = {Atmospheric CO2 data,Climate sensitivity,El Ni{\~{n}}o},
month = {nov},
number = {1760},
pages = {20170303},
title = {{History of El Ni{\~{n}}o impacts on the global carbon cycle 1957–2017: a quantification from atmospheric CO2 data}},
url = {http://rstb.royalsocietypublishing.org/lookup/doi/10.1098/rstb.2017.0303},
volume = {373},
year = {2018}
}
@article{Rios2015b,
abstract = {Global ocean acidification is caused primarily by the ocean's uptake of CO 2 as a consequence of increasing atmospheric CO 2 levels. We present observations of the oceanic decrease in pH at the basin scale (50°S–36°N) for the Atlantic Ocean over two decades (1993–2013). Changes in pH associated with the uptake of anthropogenic CO 2 ($\Delta$pHCant) and with variations caused by biological activity and ocean circulation ($\Delta$pHNat) are evaluated for different water masses. Output from an Institut Pierre Simon Laplace climate model is used to place the results into a longer-term perspective and to elucidate the mechanisms responsible for pH change. The largest decreases in pH (∆pH) were observed in central, mode, and intermediate waters, with a maximum $\Delta$pH value in South Atlantic Central Waters of −0.042 ± 0.003. The $\Delta$pH trended toward zero in deep and bottom waters. Observations and model results show that pH changes generally are dominated by the anthropogenic component, which accounts for rates between −0.0015 and −0.0020/y in the central waters. The anthropogenic and natural components are of the same order of magnitude and reinforce one another in mode and intermediate waters over the time period. Large negative $\Delta$pHNat values observed in mode and intermediate waters are driven primarily by changes in CO 2 content and are consistent with ( i ) a poleward shift of the formation region during the positive phase of the Southern Annular Mode in the South Atlantic and ( ii ) an increase in the rate of the water mass formation in the North Atlantic.},
author = {R{\'{i}}os, Aida F and Resplandy, Laure and Garc{\'{i}}a-Ib{\'{a}}{\~{n}}ez, Maribel I and Fajar, Noelia M and Velo, Anton and Padin, Xose A and Wanninkhof, Rik and Steinfeldt, Reiner and Ros{\'{o}}n, Gabriel and P{\'{e}}rez, Fiz F},
doi = {10.1073/pnas.1504613112},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {aug},
number = {32},
pages = {9950--9955},
pmid = {26216947},
publisher = {National Academy of Sciences},
title = {{Decadal acidification in the water masses of the Atlantic Ocean}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1504613112},
volume = {112},
year = {2015}
}
@article{Rabalais2014,
author = {Rabalais, Nancy N. and Cai, Wei-Jun and Carstensen, Jacob and Conley, Daniel J. and Fry, Brian and Hu, Xinping and Qui{\~{n}}ones-Rivera, Zoraida and Rosenberg, Rutger and Slomp, Caroline P. and Turner, R. Eugene and Voss, Maren and Wissel, Bj{\"{o}}rn and Zhang, Jing},
doi = {10.5670/oceanog.2014.21},
issn = {10428275},
journal = {Oceanography},
month = {mar},
number = {1},
pages = {172--183},
title = {{Eutrophication-Driven Deoxygenation in the Coastal Ocean}},
url = {https://tos.org/oceanography/article/eutrophication-driven-deoxygenation-in-the-coastal-ocean},
volume = {27},
year = {2014}
}
@article{Rabalais2010,
abstract = {Abstract. Water masses can become undersaturated with oxygen when natural processes alone or in combination with anthropogenic processes produce enough organic carbon that is aerobically decomposed faster than the rate of oxygen re-aeration. The dominant natural processes usually involved are photosynthetic carbon production and microbial respiration. The re-supply rate is indirectly related to its isolation from the surface layer. Hypoxic water masses (},
author = {Rabalais, N N and D{\'{i}}az, R. J. and Levin, L A and Turner, R E and Gilbert, D and Zhang, J},
doi = {10.5194/bg-7-585-2010},
issn = {1726-4189},
journal = {Biogeosciences},
month = {feb},
number = {2},
pages = {585--619},
title = {{Dynamics and distribution of natural and human-caused hypoxia}},
volume = {7},
year = {2010}
}
@article{Rabin:2017,
abstract = {Abstract. The important role of fire in regulating vegetation community composition and contributions to emissions of greenhouse gases and aerosols make it a critical component of dynamic global vegetation models and Earth system models. Over 2 decades of development, a wide variety of model structures and mechanisms have been designed and incorporated into global fire models, which have been linked to different vegetation models. However, there has not yet been a systematic examination of how these different strategies contribute to model performance. Here we describe the structure of the first phase of the Fire Model Intercomparison Project (FireMIP), which for the first time seeks to systematically compare a number of models. By combining a standardized set of input data and model experiments with a rigorous comparison of model outputs to each other and to observations, we will improve the understanding of what drives vegetation fire, how it can best be simulated, and what new or improved observational data could allow better constraints on model behavior. In this paper, we introduce the fire models used in the first phase of FireMIP, the simulation protocols applied, and the benchmarking system used to evaluate the models. We have also created supplementary tables that describe, in thorough mathematical detail, the structure of each model.},
author = {Rabin, Sam S and Melton, Joe R and Lasslop, Gitta and Bachelet, Dominique and Forrest, Matthew and Hantson, Stijn and Kaplan, Jed O and Li, Fang and Mangeon, St{\'{e}}phane and Ward, Daniel S and Yue, Chao and Arora, Vivek K and Hickler, Thomas and Kloster, Silvia and Knorr, Wolfgang and Nieradzik, Lars and Spessa, Allan and Folberth, Gerd A and Sheehan, Tim and Voulgarakis, Apostolos and Kelley, Douglas I and Prentice, I Colin and Sitch, Stephen and Harrison, Sandy and Arneth, Almut},
doi = {10.5194/gmd-10-1175-2017},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {mar},
number = {3},
pages = {1175--1197},
title = {{The Fire Modeling Intercomparison Project (FireMIP), phase 1: experimental and analytical protocols with detailed model descriptions}},
url = {https://www.geosci-model-dev.net/10/1175/2017/},
volume = {10},
year = {2017}
}
@article{Rae2018,
author = {Rae, J. W. B. and Burke, A. and Robinson, L. F. and Adkins, J. F. and Chen, T. and Cole, C. and Greenop, R. and Li, T. and Littley, E. F. M. and Nita, D. C. and Stewart, J. A. and Taylor, B. J.},
doi = {10.1038/s41586-018-0614-0},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7728},
pages = {569--573},
title = {{CO2 storage and release in the deep Southern Ocean on millennial to centennial timescales}},
url = {http://www.nature.com/articles/s41586-018-0614-0},
volume = {562},
year = {2018}
}
@article{Rafter2019,
author = {Rafter, Patrick A. and Carriquiry, Jos{\'{e}} D. and Herguera, Juan‐Carlos and Hain, Mathis P. and Solomon, Evan A. and Southon, John R.},
doi = {10.1029/2019GL085102},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {dec},
number = {23},
pages = {13950--13960},
title = {{Anomalous {\textgreater} 2000-Year-Old Surface Ocean Radiocarbon Age as Evidence for Deglacial Geologic Carbon Release}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GL085102},
volume = {46},
year = {2019}
}
@article{doi:10.1002/2014GB005079,
abstract = {Improved constraints on carbon cycle responses to climate change are needed to inform mitigation policy, yet our understanding of how these responses may evolve after 2100 remains highly uncertain. Using the Community Earth System Model (v1.0), we quantified climate-carbon feedbacks from 1850 to 2300 for the Representative Concentration Pathway 8.5 and its extension. In three simulations, land and ocean biogeochemical processes experienced the same trajectory of increasing atmospheric CO2. Each simulation had a different degree of radiative coupling for CO2 and other greenhouse gases and aerosols, enabling diagnosis of feedbacks. In a fully coupled simulation, global mean surface air temperature increased by 9.3 K from 1850 to 2300, with 4.4 K of this warming occurring after 2100. Excluding CO2, warming from other greenhouse gases and aerosols was 1.6 K by 2300, near a 2 K target needed to avoid dangerous anthropogenic interference with the climate system. Ocean contributions to the climate-carbon feedback increased considerably over time and exceeded contributions from land after 2100. The sensitivity of ocean carbon to climate change was found to be proportional to changes in ocean heat content, as a consequence of this heat modifying transport pathways for anthropogenic CO2 inflow and solubility of dissolved inorganic carbon. By 2300, climate change reduced cumulative ocean uptake by 330 Pg C, from 1410 Pg C to 1080 Pg C. Land fluxes similarly diverged over time, with climate change reducing stocks by 232 Pg C. Regional influence of climate change on carbon stocks was largest in the North Atlantic Ocean and tropical forests of South America. Our analysis suggests that after 2100, oceans may become as important as terrestrial ecosystems in regulating the magnitude of the climate-carbon feedback.},
author = {Randerson, J T and Lindsay, K and Munoz, E and Fu, W and Moore, J K and Hoffman, F M and Mahowald, N M and Doney, S C},
doi = {10.1002/2014GB005079},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {Atlantic meridional overturning circulation,carbon-concentration feedback,ecosystems,net primary production,stratification},
month = {jun},
number = {6},
pages = {744--759},
title = {{Multicentury changes in ocean and land contributions to the climate–carbon feedback}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014GB005079 http://doi.wiley.com/10.1002/2014GB005079},
volume = {29},
year = {2015}
}
@article{Raupach2014,
abstract = {Through 1959-2012, an airborne fraction (AF) of 0.44 of total anthropogenic CO2 emissions remained in the atmosphere, with the rest being taken up by land and ocean CO2 sinks. Understanding of this uptake is critical because it greatly alleviates the emissions reductions required for climate mitigation, and also reduces the risks and damages that adaptation has to embrace. An observable quantity that reflects sink properties more directly than the AF is the CO 2 sink rate (kS), the combined land-ocean CO2 sink flux per unit excess atmospheric CO2 above preindustrial levels. Here we show from observations thatkS declined over 1959-2012 by a factor of about 1 / 3, implying that CO2 sinks increased more slowly than excess CO2. Using a carbon-climate model, we attribute the decline inkS to four mechanisms: slower-than-exponential CO2 emissions growth (∼ 35{\%} of the trend), volcanic eruptions (∼ 25{\%}), sink responses to climate change (∼ 20{\%}), and nonlinear responses to increasing CO2, mainly oceanic (∼ 20{\%}). The first of these mechanisms is associated purely with the trajectory of extrinsic forcing, and the last two with intrinsic, feedback responses of sink processes to changes in climate and atmospheric CO2. Our results suggest that the effects of these intrinsic, nonlinear responses are already detectable in the global carbon cycle. Although continuing future decreases inkS will occur under all plausible CO2 emission scenarios, the rate of decline varies between scenarios in non-intuitive ways because extrinsic and intrinsic mechanisms respond in opposite ways to changes in emissions: extrinsic mechanisms causekS to decline more strongly with increasing mitigation, while intrinsic mechanisms causekS to decline more strongly under high-emission, low-mitigation scenarios as the carbon-climate system is perturbed further from a near-linear regime. {\textcopyright} Author(s) 2014. CC Attribution 3.0 License.},
author = {Raupach, M. R. and Gloor, M. and Sarmiento, J. L. and Canadell, J. G. and Fr{\"{o}}licher, T. L. and Gasser, T. and Houghton, R. A. and {Le Qu{\'{e}}r{\'{e}}}, C. and Trudinger, C. M.},
doi = {10.5194/bg-11-3453-2014},
issn = {17264189},
journal = {Biogeosciences},
number = {13},
pages = {3453--3475},
title = {{The declining uptake rate of atmospheric CO2 by land and ocean sinks}},
volume = {11},
year = {2014}
}
@article{Raven2021,
abstract = {Climate change is driving an expansion of marine oxygen-deficient zones, which may alter the global cycles of carbon, sulfur, nitrogen, and trace metals. Currently, however, we lack a full mechanistic understanding of how oxygen deficiency affects organic carbon cycling and burial. Here, we show that cryptic microbial sulfate reduction occurs in sinking particles from the eastern tropical North Pacific oxygen-deficient zone and that some microbially produced sulfide reacts rapidly to form organic sulfur that is resistant to acid hydrolysis. Particle-hosted sulfurization could enhance carbon preservation in sediments underlying oxygen-deficient water columns and serve as a stabilizing feedback between expanding anoxic zones and atmospheric carbon dioxide. A similar mechanism may help explain more-extreme instances of organic carbon preservation associated with marine anoxia in Earth history.},
author = {Raven, M. R. and Keil, R. G. and Webb, S. M.},
doi = {10.1126/science.abc6035},
issn = {0036-8075},
journal = {Science},
month = {jan},
number = {6525},
pages = {178--181},
title = {{Microbial sulfate reduction and organic sulfur formation in sinking marine particles}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.abc6035},
volume = {371},
year = {2021}
}
@article{Ravishankara2009,
author = {Ravishankara, A. R. and Daniel, J. S. and Portmann, R. W.},
doi = {10.1126/science.1176985},
issn = {0036-8075},
journal = {Science},
month = {oct},
number = {5949},
pages = {123--125},
title = {{Nitrous Oxide (N2O): The Dominant Ozone-Depleting Substance Emitted in the 21st Century}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1176985},
volume = {326},
year = {2009}
}
@article{Raymond2013,
abstract = {Carbon dioxide (CO2) transfer from inland waters to the atmosphere, known as CO2 evasion, is a component of the global carbon cycle. Global estimates of CO2 evasion have been hampered, however, by the lack of a framework for estimating the inland water surface area and gas transfer velocity and by the absence of a global CO2 database. Here we report regional variations in global inland water surface area, dissolved CO2 and gas transfer velocity. We obtain global CO2 evasion rates of 1.8[thinsp]nature12760-m22jpg2K3825 petagrams of carbon (Pg[thinsp]C) per year from streams and rivers and 0.32[thinsp]nature12760-m23jpg2K3425 Pg[thinsp]C[thinsp]yr-1 from lakes and reservoirs, where the upper and lower limits are respectively the 5th and 95th confidence interval percentiles. The resulting global evasion rate of 2.1[thinsp]Pg[thinsp]C[thinsp]yr-1 is higher than previous estimates owing to a larger stream and river evasion rate. Our analysis predicts global hotspots in stream and river evasion, with about 70 per cent of the flux occurring over just 20 per cent of the land surface. The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally.},
author = {Raymond, Peter A. and Hartmann, Jens and Lauerwald, Ronny and Sobek, Sebastian and McDonald, Cory and Hoover, Mark and Butman, David and Striegl, Robert and Mayorga, Emilio and Humborg, Christoph and Kortelainen, Pirkko and D{\"{u}}rr, Hans and Meybeck, Michel and Ciais, Philippe and Guth, Peter},
doi = {10.1038/nature12760},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {nov},
number = {7476},
pages = {355--359},
pmid = {24256802},
title = {{Global carbon dioxide emissions from inland waters}},
url = {https://www.nature.com/articles/nature12760 http://www.nature.com/articles/nature12760},
volume = {503},
year = {2013}
}
@article{Raynaud2005,
abstract = {The marine isotopic stage 11 (MIS 11) is an extraordinarily long interglacial period in the Earth's history that occurred some 400,000 years ago and lasted for about 30,000 years. During this period there were weak, astronomically induced changes in the distribution of solar energy reaching the Earth. The conditions of this orbital climate forcing are similar to those of today's interglacial period, and they rendered the climate susceptible to other forcing--for example, to changes in the level of atmospheric carbon dioxide. Here we use ice-core data from the Antarctic Vostok core to reconstruct a complete atmospheric carbon dioxide record for MIS 11. The record indicates that values for carbon dioxide throughout the interglacial period were close to the Earth's pre-industrial levels and that both solar energy and carbon dioxide may have helped to make MIS 11 exceptionally long. Anomalies in the oceanic carbonate system recorded in marine sediments at the time, for example while coral reefs were forming, apparently left no signature on atmospheric carbon dioxide concentrations.},
author = {Raynaud, Dominique and Barnola, Jean-Marc and Souchez, Roland and Lorrain, Reginald and Petit, Jean-Robert and Duval, Paul and Lipenkov, Vladimir Y.},
doi = {10.1038/43639b},
issn = {0028-0836},
journal = {Nature},
month = {jul},
number = {7047},
pages = {39--40},
pmid = {16001055},
title = {{The record for marine isotopic stage 11}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/16001055 http://www.nature.com/articles/436039b},
volume = {436},
year = {2005}
}
@article{REES201693,
abstract = {The effects of ocean acidification (OA) on nitrous oxide (N2O) production and on the community composition of ammonium oxidizing archaea (AOA) were examined in the northern and southern sub-polar and polar Atlantic Ocean. Two research cruises were performed during June 2012 between the North Sea and Arctic Greenland and Barent Seas, and in January–February 2013 to the Antarctic Scotia Sea. Seven stations were occupied in all during which shipboard experimental manipulations of the carbonate chemistry were performed through additions of NaHCO3−+HCl in order to examine the impact of short-term (48h for N2O and between 96 and 168h for AOA) exposure to control and elevated conditions of OA. During each experiment, triplicate incubations were performed at ambient conditions and at 3 lowered levels of pH which varied between 0.06 and 0.4 units according to the total scale and which were targeted at CO2 partial pressures of {\~{}}500, 750 and 1000µatm. The AOA assemblage in both Arctic and Antarctic regions was dominated by two major archetypes that represent the marine AOA clades most often detected in seawater. There were no significant changes in AOA assemblage composition between the beginning and end of the incubation experiments. N2O production was sensitive to decreasing pHT at all stations and decreased by between 2.4{\%} and 44{\%} with reduced pHT values of between 0.06 and 0.4. The reduction in N2O yield from nitrification was directly related to a decrease of between 28{\%} and 67{\%} in available NH3 as a result of the pH driven shift in the NH3:NH4+ equilibrium. The maximum reduction in N2O production at conditions projected for the end of the 21st century was estimated to be 0.82TgNy−1.},
annote = {Impacts of surface ocean acidification in polar seas and globally: a field-based approach},
author = {Rees, Andrew P and Brown, Ian J and Jayakumar, Amal and Ward, Bess B},
doi = {https://doi.org/10.1016/j.dsr2.2015.12.006},
issn = {0967-0645},
journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
keywords = {Ammonia,Ammonia oxidising archaea,Antarctic,Arctic,Atlantic,Nitrous oxide,Ocean acidification},
pages = {93--101},
title = {{The inhibition of N2O production by ocean acidification in cold temperate and polar waters}},
url = {http://www.sciencedirect.com/science/article/pii/S0967064515004373},
volume = {127},
year = {2016}
}
@article{Regnier2013a,
abstract = {A substantial amount of the atmospheric carbon taken up on land through photosynthesis and chemical weathering is transported laterally along the aquatic continuum from upland terrestrial ecosystems to the ocean. So far, global carbon budget estimates have implicitly assumed that the transformation and lateral transport of carbon along this aquatic continuum has remained unchanged since pre-industrial times. A synthesis of published work reveals the magnitude of present-day lateral carbon fluxes from land to ocean, and the extent to which human activities have altered these fluxes. We show that anthropogenic perturbation may have increased the flux of carbon to inland waters by as much as 1.0 Pg C yr-1 since pre-industrial times, mainly owing to enhanced carbon export from soils. Most of this additional carbon input to upstream rivers is either emitted back to the atmosphere as carbon dioxide ({\~{}}0.4 Pg C yr-1 ) or sequestered in sediments ({\~{}}0.5 Pg C yr-1 ) along the continuum of freshwater bodies, estuaries and coastal waters, leaving only a perturbation carbon input of {\~{}}0.1 Pg C yr-1 to the open ocean. According to our analysis, terrestrial ecosystems store {\~{}}0.9 Pg C yr-1 at present, which is in agreement with results from forest inventories but significantly differs from the figure of 1.5 Pg C yr-1 previously estimated when ignoring changes in lateral carbon fluxes. We suggest that carbon fluxes along the land–ocean aquatic continuum need to be included in global carbon dioxide budgets.},
author = {Regnier, Pierre and Friedlingstein, Pierre and Ciais, Philippe and Mackenzie, Fred T. and Gruber, Nicolas and Janssens, Ivan A. and Laruelle, Goulven G. and Lauerwald, Ronny and Luyssaert, Sebastiaan and Andersson, Andreas J. and Arndt, Sandra and Arnosti, Carol and Borges, Alberto V. and Dale, Andrew W. and Gallego-Sala, Angela and Godd{\'{e}}ris, Yves and Goossens, Nicolas and Hartmann, Jens and Heinze, Christoph and Ilyina, Tatiana and Joos, Fortunat and LaRowe, Douglas E. and Leifeld, Jens and Meysman, Filip J. R. and Munhoven, Guy and Raymond, Peter A. and Spahni, Renato and Suntharalingam, Parvadha and Thullner, Martin},
doi = {10.1038/ngeo1830},
isbn = {1752-0894},
journal = {Nature Geoscience},
month = {aug},
number = {8},
pages = {597--607},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Anthropogenic perturbation of the carbon fluxes from land to ocean}},
url = {http://www.nature.com/articles/ngeo1830},
volume = {6},
year = {2013}
}
@article{Reich2018,
abstract = {Theory and empirical data both support the paradigm that C4 plant species (in which the first product of carbon fixation is a four-carbon molecule) benefit less from rising carbon dioxide (CO2) concentrations than C3 species (in which the first product is a three-carbon molecule). This is because their different photosynthetic physiologies respond differently to atmospheric CO2 concentrations. Reich et al. document a reversal of this pattern in a 20-year CO2 enrichment experiment using grassland plots with each type of plant (see the Perspective by Hovenden and Newton). Over the first 12 years, biomass increased with elevated CO2 in C3 plots but not C4 plots, as expected. But over the next 8 years, the pattern reversed: Biomass increased in C4 plots but not C3 plots. Thus, even the best-supported short-term drivers of plant response to global change might not predict long-term results.},
author = {Reich, Peter B. and Hobbie, Sarah E. and Lee, Tali D. and Pastore, Melissa A.},
doi = {10.1126/science.aas9313},
issn = {0036-8075},
journal = {Science},
month = {apr},
number = {6386},
pages = {317--320},
pmid = {29674593},
title = {{Unexpected reversal of C3 versus C4 grass response to elevated CO2 during a 20-year field experiment}},
url = {http://www.sciencemag.org/lookup/doi/10.1126/science.aas9313},
volume = {360},
year = {2018}
}
@article{Reich2013a,
abstract = {The stimulation of plant growth by elevated CO2 concentration has been widely observed. Such fertilization, and associated carbon storage, could dampen future increases in atmospheric CO2 levels and associated climate warming1. However, the CO2 fertilization of plant biomass may be sensitive to nitrogen supply2–4. Herein we show that in the latest decade of a long-term perennial grassland experiment, low ambient soil nitrogen availability constrained the positive response of plant biomass to elevated CO2, a result not seen in the first years (1998–2000) of the study. From 2001 to 2010, elevated CO2 stimulated plant biomass half as much under ambient as under enriched nitrogen supply, an effect mirrored over this period by more positive effects of elevated CO2 on soil nitrogen supply (net nitrogen mineralization) and plant nitrogen status under enriched than ambient nitrogen supply. The results did not strongly support either the progressive nitrogen limitation hypothesis, or the alternative hypothesis of priming of soil nitrogen release by elevated CO2. As nitrogen limitation to productivity is widespread, persistent nitrogen constraints on terrestrial responses to rising CO2 are probably pervasive. Further incorporation of such interactions into Earth system models is recommended to better predict future CO2 fertilization effects and impacts on the global carbon cycle.},
author = {Reich, Peter B. and Hobbie, Sarah E.},
doi = {10.1038/nclimate1694},
isbn = {1758-678X},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {mar},
number = {3},
pages = {278--282},
pmid = {18620193},
publisher = {Nature Publishing Group},
title = {{Decade-long soil nitrogen constraint on the CO2 fertilization of plant biomass}},
url = {http://www.nature.com/articles/nclimate1694},
volume = {3},
year = {2013}
}
@article{Reich2014a,
author = {Reich, Peter B. and Hobbie, Sarah E. and Lee, Tali D.},
doi = {10.1038/ngeo2284},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {dec},
number = {12},
pages = {920--924},
title = {{Plant growth enhancement by elevated CO2 eliminated by joint water and nitrogen limitation}},
volume = {7},
year = {2014}
}
@article{Remmelzwaal2019,
abstract = {Over the past several decades, oxygen minimum zones have rapidly expanded due to rising temperatures raising concerns about the impacts of future climate change. One way to better understand the drivers behind this expansion is to evaluate the links between climate and seawater deoxygenation in the past especially in times of geologically abrupt climate change such as the Palaeocene-Eocene Thermal Maximum (PETM), a well-characterized period of rapid warming {\~{}}56 Ma. We have developed and applied the novel redox proxies of foraminiferal Cr isotopes ($\delta$53Cr) and Ce anomalies (Ce/Ce*) to assess changes in paleoredox conditions arising from changes in oxygen availability. Both $\delta$53Cr and Cr concentrations decrease notably over the PETM at intermediate to upper abyssal water depths, indicative of widespread reductions in dissolved oxygen concentrations. An apparent correlation between the sizes of $\delta$53Cr and benthic $\delta$18O excursions during the PETM suggests temperature is one of the main controlling factors of deoxygenation in the open ocean. Ocean Drilling Program Sites 1210 in the Pacific and 1263 in the Southeast Atlantic suggest that deoxygenation is associated with warming and circulation changes, as supported by Ce/Ce* data. Our geochemical data are supported by simulations from an intermediate complexity climate model (cGENIE), which show that during the PETM anoxia was mostly restricted to the Tethys Sea, while hypoxia was more widespread as a result of increasing atmospheric CO2 (from 1 to 6 times preindustrial values).},
author = {Remmelzwaal, Serginio R.C. and Dixon, Sophie and Parkinson, Ian J. and Schmidt, Daniela N. and Monteiro, Fanny M. and Sexton, Philip and Fehr, Manuela A. and Peacock, Caroline and Donnadieu, Yannick and James, Rachael H.},
doi = {10.1029/2018PA003372},
issn = {25724525},
journal = {Paleoceanography and Paleoclimatology},
keywords = {PETM,cerium,chromium,deoxygenation,foraminifera,hypoxia},
number = {6},
pages = {917--929},
title = {{Investigating Ocean Deoxygenation During the PETM Through the Cr Isotopic Signature of Foraminifera}},
volume = {34},
year = {2019}
}
@article{Renforth2019,
abstract = {7 billion tonnes of alkaline materials are produced globally each year as a product or by-product of industrial activity. The aqueous dissolution of these materials creates high pH solutions that dissolves CO2 to store carbon in the form of solid carbonate minerals or dissolved bicarbonate ions. Here we show that these materials have a carbon dioxide storage potential of 2.9–8.5 billion tonnes per year by 2100, and may contribute a substantial proportion of the negative emissions required to limit global temperature change to {\textless}2 °C.},
author = {Renforth, Phil},
doi = {10.1038/s41467-019-09475-5},
issn = {2041-1723},
journal = {Nature Communications},
number = {1},
pages = {1401},
title = {{The negative emission potential of alkaline materials}},
url = {https://doi.org/10.1038/s41467-019-09475-5},
volume = {10},
year = {2019}
}
@article{Renou-Wilson2019a,
abstract = {Globally, peatlands are under threat from a range of land use related factors that have a significant impact on the provision of ecosystem services, such as biodiversity and carbon (C) sequestration/storage. In Ireland, approximately 84{\%} of raised bogs (a priority habitat listed in Annex I of the EU Habitats Directive) have been affected by peat extraction. While restoration implies the return of ecosystem services that were characteristic of the pre-disturbed ecosystem, achieving this goal is often a challenge in degraded peatlands as post-drainage conditions vary considerably between sites. Here, we present multi-year greenhouse gas (GHG) and vegetation dynamics data from two former raised bogs in Ireland that were drained and either industrially extracted (milled) or cut on the margins for domestic use and subsequently rewetted (with no further management). When upscaled to the ecosystem level, the rewetted nutrient poor domestic cutover peatland was a net sink of carbon dioxide (CO2) (−49 ± 66 g C m−2 yr−1) and a source of methane (CH4) (19.7 ± 5 g C m−2 yr−1), while the nutrient rich industrial cutaway was a net source of CO2 (0.66 ± 168 g C m−2 yr−1) and CH4 (5.0 ± 2.2 g C m−2 yr−1). The rewetted domestic cutover site exhibited the expected range of micro-habitats and species composition found in natural (non-degraded) counterparts. In contrast, despite successful rewetting, the industrially extracted peatland did not exhibit typical raised bog flora. This study demonstrated that environmental and management variables can influence species composition and, therefore, the regeneration of species typical of natural sites, and has highlighted the climate benefits from rewetting degraded peatlands in terms of reduced GHG emissions. However, rewetting of degraded peatlands is a major challenge and in some cases reintroduction of bryophytes typical of natural raised bogs may be more difficult than the achievement of proper GHG emission savings.},
author = {Renou-Wilson, F and Moser, G and Fallon, D and Farrell, C A and M{\"{u}}ller, C and Wilson, D},
doi = {10.1016/j.ecoleng.2018.02.014},
issn = {0925-8574},
journal = {Ecological Engineering},
pages = {547--560},
title = {{Rewetting degraded peatlands for climate and biodiversity benefits: Results from two raised bogs}},
volume = {127},
year = {2019}
}
@article{Resplandy2013,
abstract = {Consistent with recent observations, Coupled Model Intercomparison Project 5 Earth System Models project highest acidification rates in subsurface waters. Using seven Earth System Models, we find that high acidification rates in mode and intermediate waters (MIW) on centennial time scales (?0.0008 to ?0.0023 ± 0.0001?yr?1 depending on the scenario) are predominantly explained by the geochemical effect of increasing atmospheric CO2, whereas physical and biological climate change feedbacks explain less than 10{\%} of the simulated changes. MIW are characterized by a larger surface area to volume ratio than deep and bottom waters leading to 5 to 10 times larger carbon uptake. In addition, MIW geochemical properties result in a sensitivity to increasing carbon concentration twice larger than surface waters (?H+ of +1.2?10?4?mmol?m?3 for every mmol?m?3 of dissolved carbon in MIW versus +0.6?10?4 in surface waters). Low pH transported by mode and intermediate waters is likely to influence surface pH in upwelling regions decades after their isolation from the atmosphere.?},
author = {Resplandy, L and Bopp, L and Orr, J C and Dunne, J P},
doi = {10.1002/grl.50414},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {CMIP5,acidification,intermediate waters,mode waters},
month = {jun},
number = {12},
pages = {3091--3095},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Role of mode and intermediate waters in future ocean acidification: Analysis of CMIP5 models}},
url = {https://doi.org/10.1002/grl.50414},
volume = {40},
year = {2013}
}
@article{Resplandy2018a,
abstract = {Measurements of atmospheric CO2 concentration provide a tight constraint on the sum of the land and ocean sinks. This constraint has been combined with estimates of ocean carbon flux and riverine transport of carbon from land to oceans to isolate the land sink. Uncertainties in the ocean and river fluxes therefore translate into uncertainties in the land sink. Here, we introduce a heat-based constraint on the latitudinal distribution of ocean and river carbon fluxes, and reassess the partition between ocean, river and land in the tropics, and in the southern and northern extra-tropics. We show that the ocean overturning circulation and biological pump tightly link the ocean transports of heat and carbon between hemispheres. Using this coupling between heat and carbon, we derive ocean and river carbon fluxes compatible with observational constraints on heat transport. This heat-based constraint requires a 20–100{\%} stronger ocean and river carbon transport from the Northern Hemisphere to the Southern Hemisphere than existing estimates, and supports an upward revision of the global riverine carbon flux from 0.45 to 0.78 PgC yr−1. These systematic biases in existing ocean/river carbon fluxes redistribute up to 40{\%} of the carbon sink between northern, tropical and southern land ecosystems. As a consequence, the magnitude of both the southern land source and the northern land sink may have to be substantially reduced.},
author = {Resplandy, L. and Keeling, R. F. and R{\"{o}}denbeck, C. and Stephens, B. B. and Khatiwala, S. and Rodgers, K. B. and Long, M. C. and Bopp, L. and Tans, P. P.},
doi = {10.1038/s41561-018-0151-3},
isbn = {4156101801513},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jul},
number = {7},
pages = {504--509},
publisher = {Springer US},
title = {{Revision of global carbon fluxes based on a reassessment of oceanic and riverine carbon transport}},
url = {http://www.nature.com/articles/s41561-018-0151-3},
volume = {11},
year = {2018}
}
@article{Reuter2017a,
abstract = {The conventional and established estimates of the amount of carbon taken up by the European terrestrial biosphere from the Atlantic to the Urals rely on two conceptually different types of ground-based measurements. On the one hand, in situ measurements of atmospheric CO 2 concentrations are globally obtained at about 100 sites on a regular basis. On the other hand, conventional bottom-up estimates of surface carbon fluxes are obtained from field measurements. Additional in situ measurement sites are needed to better constrain the surface fluxes of the northeastern part of Europe with inverse models, where the strongest uptake is expected. Field campaigns in this region, including flux and biomass measurements, can contribute to bottom-up estimates and serve as an additional anchor point for ABC satellite measurements. Regularly updated inventories and land cover classification are also essential for reliable bottom-up estimates. Likewise, reliable estimates of the flux uncertainties from bottom-up methods that should include all kinds of upscaling uncertainties and propagated measurement errors are essential. In addition to the continuation of existing satellite missions, new satellite missions are needed to provide denser and more accurate and precise measurements of the atmospheric CO 2 concentration.},
author = {Reuter, M. and Buchwitz, M. and Hilker, M. and Heymann, J. and Bovensmann, H. and Burrows, J. P. and Houweling, S. and Liu, Y. Y. and Nassar, R. and Chevallier, F. and Ciais, P. and Marshall, J. and Reichstein, M.},
doi = {10.1175/BAMS-D-15-00310.1},
issn = {0003-0007},
journal = {Bulletin of the American Meteorological Society},
month = {apr},
number = {4},
pages = {665--671},
title = {{How Much CO2 Is Taken Up by the European Terrestrial Biosphere?}},
url = {https://journals.ametsoc.org/bams/article/98/4/665/216036/How-Much-CO2-Is-Taken-Up-by-the-European},
volume = {98},
year = {2017}
}
@article{Revelle1957a,
abstract = {From a comparison of C14/C12 and C13/C12 ratios in wood and in marine material and from a slight decrease of the C14 concentration in terrestrial plants over the past 50 years it can be concluded that the average lifetime of a CO2 molecule in the atmosphere before it is dissolved into the sea is of the order of 10 years. This means that most of the CO2 released by artificial fuel combustion since the beginning of the industrial revolution must have been absorbed by the oceans. The increase of atmospheric CO2 from this cause is at present small but may become significant during future decades if industrial fuel combustion continues to rise exponentially. Present data on the total amount of CO2 in the atmosphere, on the rates and mechanisms of exchange, and on possible fluctuations in terrestrial and marine organic carbon, are inadequate for accurate measurement of future changes in atmospheric CO2. An opportunity exists during the International Geophysical Year to obtain much of the necessary information.},
author = {Revelle, Roger and Suess, Hans E.},
doi = {10.1111/j.2153-3490.1957.tb01849.x},
issn = {00402826},
journal = {Tellus},
month = {feb},
number = {1},
pages = {18--27},
publisher = {Taylor {\&} Francis},
title = {{Carbon Dioxide Exchange Between Atmosphere and Ocean and the Question of an Increase of Atmospheric CO2 during the Past Decades}},
volume = {9},
year = {1957}
}
@article{Reyer20155,
abstract = {Summary: Anthropogenic global change compromises forest resilience, with profound impacts to ecosystem functions and services. This synthesis paper reflects on the current understanding of forest resilience and potential tipping points under environmental change and explores challenges to assessing responses using experiments, observations and models. Forests are changing over a wide range of spatio-temporal scales, but it is often unclear whether these changes reduce resilience or represent a tipping point. Tipping points may arise from interactions across scales, as processes such as climate change, land-use change, invasive species or deforestation gradually erode resilience and increase vulnerability to extreme events. Studies covering interactions across different spatio-temporal scales are needed to further our understanding. Combinations of experiments, observations and process-based models could improve our ability to project forest resilience and tipping points under global change. We discuss uncertainties in changing CO2 concentration and quantifying tree mortality as examples. Synthesis. As forests change at various scales, it is increasingly important to understand whether and how such changes lead to reduced resilience and potential tipping points. Understanding the mechanisms underlying forest resilience and tipping points would help in assessing risks to ecosystems and presents opportunities for ecosystem restoration and sustainable forest management. As forests change at various scales, it is increasingly important to understand whether and how such changes lead to reduced resilience and potential tipping points. Understanding the mechanisms underlying forest resilience and tipping points would help in assessing risks to ecosystems and presents opportunities for ecosystem restoration and sustainable forest management. {\textcopyright} 2015 British Ecological Society.},
annote = {cited By 81},
author = {Reyer, C P O and Brouwers, N and Rammig, A and Brook, B W and Epila, J and Grant, R F and Holmgren, M and Langerwisch, F and Leuzinger, S and Lucht, W and Medlyn, B and Pfeifer, M and Steinkamp, J and Vanderwel, M C and Verbeeck, H and Villela, D M},
doi = {10.1111/1365-2745.12337},
journal = {Journal of Ecology},
number = {1},
pages = {5--15},
title = {{Forest resilience and tipping points at different spatio-temporal scales: Approaches and challenges}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921931327{\&}doi=10.1111{\%}2F1365-2745.12337{\&}partnerID=40{\&}md5=bdeee33882e38dd229afc6097a2a2932},
volume = {103},
year = {2015}
}
@article{Rhodes2017,
author = {Rhodes, Rachael H and Brook, Edward J and McConnell, Joseph R and Blunier, Thomas and Sime, Louise C and Fa{\"{i}}n, Xavier and Mulvaney, Robert},
doi = {10.1002/2016GB005570},
journal = {Global Biogeochemical Cycles},
keywords = {10.1002/2016GB005570 and methane,Last Glacial Period,atmospheric composition,centennial variability,ice cores,paleoclimate},
pages = {575--590},
title = {{Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period}},
volume = {31},
year = {2017}
}
@article{Riahi2017,
author = {Riahi, Keywan and van Vuuren, Detlef P. and Kriegler, Elmar and Edmonds, Jae and O'Neill, Brian C. and Fujimori, Shinichiro and Bauer, Nico and Calvin, Katherine and Dellink, Rob and Fricko, Oliver and Lutz, Wolfgang and Popp, Alexander and Cuaresma, Jesus Crespo and KC, Samir and Leimbach, Marian and Jiang, Leiwen and Kram, Tom and Rao, Shilpa and Emmerling, Johannes and Ebi, Kristie and Hasegawa, Tomoko and Havlik, Petr and Humpen{\"{o}}der, Florian and {Da Silva}, Lara Aleluia and Smith, Steve and Stehfest, Elke and Bosetti, Valentina and Eom, Jiyong and Gernaat, David and Masui, Toshihiko and Rogelj, Joeri and Strefler, Jessica and Drouet, Laurent and Krey, Volker and Luderer, Gunnar and Harmsen, Mathijs and Takahashi, Kiyoshi and Baumstark, Lavinia and Doelman, Jonathan C. and Kainuma, Mikiko and Klimont, Zbigniew and Marangoni, Giacomo and Lotze-Campen, Hermann and Obersteiner, Michael and Tabeau, Andrzej and Tavoni, Massimo},
doi = {10.1016/j.gloenvcha.2016.05.009},
issn = {09593780},
journal = {Global Environmental Change},
month = {jan},
pages = {153--168},
title = {{The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An overview}},
volume = {42},
year = {2017}
}
@article{Rice10791,
abstract = {There is no scientific consensus on the drivers of the atmospheric methane growth rate over the past three decades. Here, we report carbon and hydrogen isotopic measurements of atmospheric methane in archived air samples collected 1977{\{}$\backslash$textendash{\}}1998, and modeling of these with more contemporary data to infer changes in methane sources over the period 1984{\{}$\backslash$textendash{\}}2009. We present strong evidence that methane emissions from fossil fuel sectors were approximately constant in the 1980s and 1990s but increased significantly between 2000 and 2009. This finding challenges recent conclusions based on atmospheric ethane that fugitive fossil fuel emissions fell during much of this period. Emissions from other anthropogenic sources also increased, but were partially offset by reductions in wetland and fire emissions.Observations of atmospheric methane (CH4) since the late 1970s and measurements of CH4 trapped in ice and snow reveal a meteoric rise in concentration during much of the twentieth century. Since 1750, levels of atmospheric CH4 have more than doubled to current globally averaged concentration near 1,800 ppb. During the late 1980s and 1990s, the CH4 growth rate slowed substantially and was near or at zero between 1999 and 2006. There is no scientific consensus on the drivers of this slowdown. Here, we report measurements of the stable isotopic composition of atmospheric CH4 (13C/12C and D/H) from a rare air archive dating from 1977 to 1998. Together with more modern records of isotopic atmospheric CH4, we performed a time-dependent retrieval of methane fluxes spanning 25 y (1984{\{}$\backslash$textendash{\}}2009) using a 3D chemical transport model. This inversion results in a 24 [18, 27] Tg y-1 CH4 increase in fugitive fossil fuel emissions since 1984 with most of this growth occurring after year 2000. This result is consistent with some bottom-up emissions inventories but not with recent estimates based on atmospheric ethane. In fact, when forced with decreasing emissions from fossil fuel sources our inversion estimates unreasonably high emissions in other sources. Further, the inversion estimates a decrease in biomass-burning emissions that could explain falling ethane abundance. A range of sensitivity tests suggests that these results are robust.},
author = {Rice, Andrew L and Butenhoff, Christopher L and Teama, Doaa G and R{\"{o}}ger, Florian H and Khalil, M Aslam K and Rasmussen, Reinhold A},
doi = {10.1073/pnas.1522923113},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {sep},
number = {39},
pages = {10791--10796},
publisher = {National Academy of Sciences},
title = {{Atmospheric methane isotopic record favors fossil sources flat in 1980s and 1990s with recent increase}},
url = {http://www.pnas.org/content/113/39/10791 http://www.pnas.org/lookup/doi/10.1073/pnas.1522923113},
volume = {113},
year = {2016}
}
@article{Richardson2018,
author = {Richardson, Mark and Cowtan, Kevin and Millar, Richard J},
doi = {10.1088/1748-9326/aab305},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {may},
number = {5},
pages = {054004},
publisher = {IOP Publishing},
title = {{Global temperature definition affects achievement of long-term climate goals}},
url = {http://stacks.iop.org/1748-9326/13/i=5/a=054004?key=crossref.0ce4fea65c3c516e4cbb008f221e239b},
volume = {13},
year = {2018}
}
@article{Richardson2019,
abstract = {Carbon fixation by phytoplankton near the surface and the sinking of this particulate material to deeper waters are key components of the biological carbon pump. The efficiency of the biological pump is influenced by the size and taxonomic composition of the phytoplankton community. Large, heavily ballasted taxa such as diatoms sink quickly and thus efficiently remove fixed carbon from the upper ocean. Smaller, nonballasted species such as picoplanktonic cyanobacteria are usually thought to contribute little to export production. Research in the past decade, however, has shed new light on the potential importance of small phytoplankton to carbon export, especially in oligotrophic oceans, where small cells dominate primary productivity. Here, I examine the mechanisms and pathways through which small-phytoplankton carbon is exported from the surface ocean and the role of small phytoplankton in food webs of a variety of ocean ecosystems.},
author = {Richardson, Tammi L.},
doi = {10.1146/annurev-marine-121916-063627},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {57--74},
title = {{Mechanisms and Pathways of Small-Phytoplankton Export from the Surface Ocean}},
url = {https://www.annualreviews.org/doi/10.1146/annurev-marine-121916-063627},
volume = {11},
year = {2019}
}
@article{Ricke2014a,
author = {Ricke, Katharine L and Caldeira, Ken},
doi = {10.1088/1748-9326/9/12/124002},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {dec},
number = {12},
pages = {124002},
publisher = {IOP Publishing},
title = {{Maximum warming occurs about one decade after a carbon dioxide emission}},
url = {http://stacks.iop.org/1748-9326/9/i=12/a=124002?key=crossref.3a6968619a8a2460d3fb1b042430df71},
volume = {9},
year = {2014}
}
@article{Rigby2008,
abstract = {Following almost a decade with little change in global atmospheric methane mole fraction, we present measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) networks that show renewed growth starting near the beginning of 2007. Remarkably, a similar growth rate is found at all monitoring locations from this time until the latest measurements. We use these data, along with an inverse method applied to a simple model of atmospheric chemistry and transport, to investigate the possible drivers of the rise. Specifically, the relative roles of an increase in emission rate or a decrease in concentration of the hydroxyl radical, the largest methane sink, are examined. We conclude that: 1) if the annual mean hydroxyl radical concentration did not change, a substantial increase in emissions was required simultaneously in both hemispheres between 2006 and 2007; 2) if a small drop in the hydroxyl radical concentration occurred, consistent with AGAGE methyl chloroform measurements, the emission increase is more strongly biased to the Northern Hemisphere.},
author = {Rigby, M. and Prinn, R. G. and Fraser, P. J. and Simmonds, P. G. and Langenfelds, R. L. and Huang, J. and Cunnold, D. M. and Steele, L. P. and Krummel, P. B. and Weiss, R. F. and O'Doherty, S. and Salameh, P. K. and Wang, H. J. and Harth, C. M. and M{\"{u}}hle, J. and Porter, L. W.},
doi = {10.1029/2008GL036037},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {nov},
number = {22},
pages = {L22805},
publisher = {Wiley-Blackwell},
title = {{Renewed growth of atmospheric methane}},
url = {http://doi.wiley.com/10.1029/2008GL036037},
volume = {35},
year = {2008}
}
@article{Rigby2017,
abstract = {The growth in global methane (CH4) concentration, which had been ongoing since the industrial revolution, stalled around the year 2000 before resuming globally in 2007. We evaluate the role of the hydroxyl radical (OH), the major CH4 sink, in the recent CH4 growth. We also examine the influence of systematic uncertainties in OH concentrations on CH4 emissions inferred from atmospheric observations. We use observations of 1,1,1trichloroethane (CH3CCl3), which is lost primarily through reaction with OH, to estimate OH levels as well as CH3CCl3 emissions, which have uncertainty that previously limited the accuracy of OH estimates. We find a 64-70{\%} probability that a decline in OH has contributed to the post-2007 methane rise. Our median solution suggests that CH4 emissions increased relatively steadily during the late 1990s and early 2000s, after which growth was more modest. This solution obviates the need for a sudden statistically significant change in total CH4 emissions around the year 2007 to explain the atmospheric observations and can explain some of the decline in the atmospheric 13CH(4)/(CH4)-C-12 ratio and the recent growth in C2H6. Our approach indicates that significant OH- related uncertainties in the CH4 budget remain, and we find that it is not possible to implicate, with a high degree of confidence, rapid global CH4 emissions changes as the primary driver of recent trends when our inferred OH trends and these uncertainties are considered.},
author = {Rigby, Matthew and Montzka, Stephen A and Prinn, Ronald G and White, James W C and Young, Dickon and O'Doherty, Simon and Lunt, Mark F and Ganesan, Anita L and Manning, Alistair J and Simmonds, Peter G and Salameh, Peter K and Harth, Christina M and Muehle, Jens and Weiss, Ray F and Fraser, Paul J and Steele, L Paul and Krummel, Paul B and McCulloch, Archie and Park, Sunyoung},
doi = {10.1073/pnas.1616426114},
isbn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {21},
pages = {5373--5377},
title = {{Role of atmospheric oxidation in recent methane growth}},
volume = {114},
year = {2017}
}
@article{bg-8-2137-2011,
abstract = {Abstract. The existence of a feedback between climate and methane (CH4) emissions from wetlands has previously been hypothesized, but both its sign and amplitude remain unknown. Moreover, this feedback could interact with the climate-CO2 cycle feedback, which has not yet been accounted for at the global scale. These interactions relate to (i) the effect of atmospheric CO2 on methanogenic substrates by virtue of its fertilizing effect on plant productivity and (ii) the fact that a climate perturbation due to CO2 (respectively CH4) radiative forcing has an effect on wetland CH4 emissions (respectively CO2 fluxes at the surface/atmosphere interface). We present a theoretical analysis of these interactions, which makes it possible to express the magnitude of the feedback for CO2 and CH4 alone, the additional gain due to interactions between these two feedbacks and the effects of these feedbacks on the difference in atmospheric CH4 and CO2 between 2100 and pre-industrial time (respectively $\Delta$CH4 and $\Delta$CO2). These gains are expressed as functions of different sensitivity terms, which we estimate based on prior studies and from experiments performed with the global terrestrial vegetation model ORCHIDEE. Despite high uncertainties on the sensitivity of wetland CH4 emissions to climate, we found that the absolute value of the gain of the climate-CH4 feedback from wetlands is relatively low ({\textless}30 {\%} of climate-CO2 feedback gain), with either negative or positive sign within the range of estimates. Whereas the interactions between the two feedbacks have low influence on $\Delta$CO2, the $\Delta$CH4 could increase by 475 to 1400 ppb based on the sign of the C-CH4 feedback gain. Our study suggests that it is necessary to better constrain the evolution of wetland area under future climate change as well as the local coupling through methanogenesis substrate of the carbon and CH4 cycles – in particular the magnitude of the CO2 fertilization effect on the wetland CH4 emissions – as these are the dominant sources of uncertainty in our model.},
author = {Ringeval, B and Friedlingstein, P and Koven, C and Ciais, P and de Noblet-Ducoudr{\'{e}}, N and Decharme, B and Cadule, P},
doi = {10.5194/bg-8-2137-2011},
issn = {1726-4189},
journal = {Biogeosciences},
month = {aug},
number = {8},
pages = {2137--2157},
title = {{Climate–CH4 feedback from wetlands and its interaction with the climate–CO2 feedback}},
url = {https://www.biogeosciences.net/8/2137/2011/},
volume = {8},
year = {2011}
}
@article{Robbins2013,
abstract = {Marine surface waters are being acidified due to uptake of anthropogenic carbon dioxide, resulting in surface ocean areas of undersaturation with respect to carbonate minerals, including aragonite. In the Arctic Ocean, acidification is expected to occur at an accelerated rate with respect to the global oceans, but a paucity of baseline data has limited our understanding of the extent of Arctic undersaturation and of regional variations in rates and causes. The lack of data has also hindered refinement of models aimed at projecting future trends of ocean acidification. Here, based on more than 34,000 data records collected in 2010 and 2011, we establish a baseline of inorganic carbon data (pH, total alkalinity, dissolved inorganic carbon, partial pressure of carbon dioxide, and aragonite saturation index) for the western Arctic Ocean. This data set documents aragonite undersaturation in ∼20{\%} of the surface waters of the combined Canada and Makarov basins, an area characterized by recent acceleration of sea ice loss. Conservative tracer studies using stable oxygen isotopic data from 307 sites show that while the entire surface of this area receives abundant freshwater from meteoric sources, freshwater from sea ice melt is most closely linked to the areas of carbonate mineral undersaturation. These data link the Arctic Ocean's largest area of aragonite undersaturation to sea ice melt and atmospheric CO2 absorption in areas of low buffering capacity. Some relatively supersaturated areas can be linked to localized biological activity. Collectively, these observations can be used to project trends of ocean acidification in higher latitude marine surface waters where inorganic carbon chemistry is largely influenced by sea ice meltwater.},
author = {Robbins, Lisa L. and Wynn, Jonathan G. and Lisle, John T. and Yates, Kimberly K. and Knorr, Paul O. and Byrne, Robert H. and Liu, Xuewu and Patsavas, Mark C. and Azetsu-Scott, Kumiko and Takahashi, Taro},
doi = {10.1371/journal.pone.0073796},
editor = {Paranhos, Rodolfo},
issn = {1932-6203},
journal = {PLOS ONE},
month = {sep},
number = {9},
pages = {e73796},
publisher = {Public Library of Science},
title = {{Baseline Monitoring of the Western Arctic Ocean Estimates 20{\%} of Canadian Basin Surface Waters Are Undersaturated with Respect to Aragonite}},
url = {https://dx.plos.org/10.1371/journal.pone.0073796},
volume = {8},
year = {2013}
}
@article{Robinson2019,
abstract = {Microbial plankton respiration is the key determinant in the balance between the storage of organic carbon in the oceans or its conversion to carbon dioxide with accompanying consumption of dissolved oxygen. Over the past fifty years, dissolved oxygen concentrations have decreased in many parts of the world's oceans, and this trend of ocean deoxygenation is predicted to continue. Yet despite its pivotal role in ocean deoxygenation, microbial respiration remains one of the least constrained microbial metabolic processes. Improved understanding of the magnitude and variability of respiration, including attribution to component plankton groups, and quantification of the respiratory quotient, would enable better predictions and projections of the intensity and extent of ocean deoxygenation and of the integrative impact of ocean deoxygenation, ocean acidification, warming, and changes in nutrient concentration and stoichiometry on marine carbon storage. This study will synthesize current knowledge of respiration in relation to deoxygenation, including the drivers of its variability, identify key unknowns in our ability to project future scenarios and suggest methodological approaches to move the field forward.},
author = {Robinson, Carol},
doi = {10.3389/fmars.2018.00533},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {jan},
pages = {533},
title = {{Microbial respiration, the engine of ocean deoxygenation}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2018.00533},
volume = {5},
year = {2019}
}
@article{doi:10.1002/2013GL058799,
abstract = {Artificial ocean iron fertilization (OIF) enhances phytoplankton productivity and is being explored as a means of sequestering anthropogenic carbon within the deep ocean. To be considered successful, carbon should be exported from the surface ocean and isolated from the atmosphere for an extended period (e.g., the Intergovernmental Panel on Climate Change's standard 100 year time horizon). This study assesses the impact of deep circulation on carbon sequestered by OIF in the Southern Ocean, a high-nutrient low-chlorophyll region known to be iron stressed. A Lagrangian particle-tracking approach is employed to analyze water mass trajectories over a 100 year simulation. By the end of the experiment, for a sequestration depth of 1000 m, 66{\%} of the carbon had been reexposed to the atmosphere, taking an average of 37.8 years. Upwelling occurs predominately within the Antarctic Circumpolar Current due to Ekman suction and topography. These results emphasize that successful OIF is dependent on the physical circulation, as well as the biogeochemistry.},
author = {Robinson, J and Popova, E E and Yool, A and Srokosz, M and Lampitt, R S and Blundell, J R},
doi = {10.1002/2013GL058799},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Lagrangian particle tracking,Southern Ocean,deep circulation,ocean iron fertilization},
month = {apr},
number = {7},
pages = {2489--2495},
title = {{How deep is deep enough? Ocean iron fertilization and carbon sequestration in the Southern Ocean}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013GL058799 http://doi.wiley.com/10.1002/2013GL058799},
volume = {41},
year = {2014}
}
@article{Roderick2015,
author = {Roderick, Michael L and Greve, Peter and Farquhar, Graham D.},
doi = {10.1002/2015WR017031},
issn = {0043-1397},
journal = {Water Resources Research},
month = {jul},
number = {7},
pages = {5450--5463},
title = {{On the assessment of aridity with changes in atmospheric CO2}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2015WR017031},
volume = {51},
year = {2015}
}
@article{Rodgers2020a,
abstract = {A positive marine chemistry-climate feedback was originally proposed by Revelle and Suess (1957, https://doi.org/10.3402/tellusa.v9i1.9075), whereby the invasion flux of anthropogenic carbon into the ocean serves to inhibit future marine CO2 uptake through reductions to the buffering capacity of surface seawater. Here we use an ocean circulation-carbon cycle model to identify an upper limit on the impact of reemergence of anthropogenic carbon into the ocean's mixed layer on the cumulative airborne fraction of CO2 in the atmosphere. We find under an RCP8.5 emissions pathway (with steady circulation) that the cumulative airborne fraction of CO2 has a sevenfold reduction by 2100 when the CO2 buffering capacity of surface seawater is maintained at preindustrial levels. Our results indicate that the effect of reemergence of anthropogenic carbon into the mixed layer on the buffering capacity of CO2 amplifies the transient climate sensitivity of the Earth system.},
author = {Rodgers, K. B. and Schlunegger, S. and Slater, R. D. and Ishii, M. and Fr{\"{o}}licher, T. L. and Toyama, K. and Plancherel, Y. and Aumont, O. and Fassbender, A. J.},
doi = {10.1029/2020GL089275},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {carbon cycle,feedback,modeling,ocean},
month = {sep},
number = {18},
publisher = {Blackwell Publishing Ltd},
title = {{Reemergence of Anthropogenic Carbon Into the Ocean's Mixed Layer Strongly Amplifies Transient Climate Sensitivity}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2020GL089275},
volume = {47},
year = {2020}
}
@article{Rogelj2018,
abstract = {The 2015 Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 1.5 °C. The transition pathways that can meet such a target have not, however, been extensively explored. Here we describe scenarios that limit end-of-century radiative forcing to 1.9 W m-2, and consequently restrict median warming in the year 2100 to below 1.5 °C. We use six integrated assessment models and a simple climate model, under different socio-economic, technological and resource assumptions from five Shared Socio-economic Pathways (SSPs). Some, but not all, SSPs are amenable to pathways to 1.5 °C. Successful 1.9 W m-2 scenarios are characterized by a rapid shift away from traditional fossil-fuel use towards large-scale low-carbon energy supplies, reduced energy use, and carbon-dioxide removal. However, 1.9 W m-2 scenarios could not be achieved in several models under SSPs with strong inequalities, high baseline fossil-fuel use, or scattered short-term climate policy. Further research can help policy-makers to understand the real-world implications of these scenarios.},
author = {Rogelj, Joeri and Popp, Alexander and Calvin, Katherine V. and Luderer, Gunnar and Emmerling, Johannes and Gernaat, David and Fujimori, Shinichiro and Strefler, Jessica and Hasegawa, Tomoko and Marangoni, Giacomo and Krey, Volker and Kriegler, Elmar and Riahi, Keywan and van Vuuren, Detlef P. and Doelman, Jonathan and Drouet, Laurent and Edmonds, Jae and Fricko, Oliver and Harmsen, Mathijs and Havl{\'{i}}k, Petr and Humpen{\"{o}}der, Florian and Stehfest, Elke and Tavoni, Massimo},
doi = {10.1038/s41558-018-0091-3},
issn = {1758-678X},
journal = {Nature Climate Change},
keywords = {Climate,Energy and society,Energy modelling,Socioeconomic scenarios,change mitigation},
month = {apr},
number = {4},
pages = {325--332},
publisher = {Nature Publishing Group},
title = {{Scenarios towards limiting global mean temperature increase below 1.5 °C}},
url = {https://doi.org/10.1038/s41558-018-0091-3 http://www.nature.com/articles/s41558-018-0091-3},
volume = {8},
year = {2018}
}
@article{Rogelj2016,
abstract = {Estimates of carbon budgets compatible with limiting warming to below specific temperature limits are reviewed, and reasons underlying their differences discussed along with their respective strengths and limitations.},
author = {Rogelj, Joeri and Schaeffer, Michiel and Friedlingstein, Pierre and Gillett, Nathan P. and van Vuuren, Detlef P. and Riahi, Keywan and Allen, Myles and Knutti, Reto},
doi = {10.1038/nclimate2868},
issn = {1758-678X},
journal = {Nature Climate Change},
keywords = {Climate,Climate change,change mitigation},
month = {mar},
number = {3},
pages = {245--252},
publisher = {Nature Publishing Group},
title = {{Differences between carbon budget estimates unravelled}},
url = {http://www.nature.com/articles/nclimate2868},
volume = {6},
year = {2016}
}
@incollection{IPCC2018,
author = {Rogelj, J. and Shindell, D. and Jiang, K. and Fifita, S. and Forster, P. and Ginzburg, V. and Handa, C. and Kheshgi, H. and Kobayashi, S. and Kriegler, E. and Mundaca, L. and S{\'{e}}f{\'{e}}rian, R. and Vilari{\~{n}}o, M.V.},
booktitle = {Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change,},
chapter = {2},
editor = {Masson-Delmotte, V. and Zhai, P. and P{\"{o}}rtner, H.-O. and Roberts, D. and Skea, J. and Shukla, P.R. and Pirani, A. and Moufouma-Okia, W. and P{\'{e}}an, C. and Pidcock, R. and Connors, S. and Matthews, J.B.R. and Chen, Y. and Zhou, X. and Gomis, M.I. and Lonnoy, E. and Maycock, T. and Tignor, M. and Waterfield, T.},
pages = {93--174},
publisher = {In Press},
title = {{Mitigation Pathways Compatible with 1.5°C in the Context of Sustainable Development}},
url = {https://www.ipcc.ch/sr15/chapter/chapter-2},
year = {2018}
}
@article{Rogelj2012,
abstract = {Climate projections for the fourth assessment report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) were based on scenarios from the Special Report on Emissions Scenarios (SRES) and simulations of the third phase of the Coupled Model Intercomparison Project (CMIP3). Since then, a new set of four scenarios (the representative concentration pathways or RCPs) was designed. Climate projections in the IPCC fifth assessment report (AR5) will be based on the fifth phase of the Coupled Model Intercomparison Project (CMIP5), which incorporates the latest versions of climate models and focuses on RCPs. This implies that by AR5 both models and scenarios will have changed, making a comparison with earlier literature challenging. To facilitate this comparison, we provide probabilistic climate projections of both SRES scenarios and RCPs in a single consistent framework. These estimates are based on a model set-up that probabilistically takes into account the overall consensus understanding of climate sensitivity uncertainty, synthesizes the understanding of climate system and carbon-cycle behaviour, and is at the same time constrained by the observed historical warming. {\textcopyright} 2012 Macmillan Publishers Limited. All rights reserved.},
author = {Rogelj, Joeri and Meinshausen, Malte and Knutti, Reto},
doi = {10.1038/nclimate1385},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {apr},
number = {4},
pages = {248--253},
title = {{Global warming under old and new scenarios using IPCC climate sensitivity range estimates}},
url = {http://www.nature.com/articles/nclimate1385},
volume = {2},
year = {2012}
}
@article{Rogelj2015c,
author = {Rogelj, Joeri and Reisinger, Andy and McCollum, David L and Knutti, Reto and Riahi, Keywan and Meinshausen, Malte},
doi = {10.1088/1748-9326/10/7/075003},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jul},
number = {7},
pages = {075003},
publisher = {IOP Publishing},
title = {{Mitigation choices impact carbon budget size compatible with low temperature goals}},
url = {http://stacks.iop.org/1748-9326/10/i=7/a=075003?key=crossref.df1d5baf002d2375258acf4fded22b3f},
volume = {10},
year = {2015}
}
@article{Rogelj2015,
author = {Rogelj, Joeri and Meinshausen, Malte and Schaeffer, Michiel and Knutti, Reto and Riahi, Keywan},
doi = {10.1088/1748-9326/10/7/075001},
journal = {Environmental Research Letters},
month = {jul},
number = {7},
pages = {075001},
publisher = {IOP Publishing},
title = {{Impact of short-lived non-CO2 mitigation on carbon budgets for stabilizing global warming}},
url = {http://stacks.iop.org/1748-9326/10/i=7/a=075001?key=crossref.f848653474225e744cc64bb0190b3170},
volume = {10},
year = {2015}
}
@article{Rogelj2019,
abstract = {Research reported during the past decade has shown that global warming is roughly proportional to the total amount of carbon dioxide released into the atmosphere. This makes it possible to estimate the remaining carbon budget: the total amount of anthropogenic carbon dioxide that can still be emitted into the atmosphere while holding the global average temperature increase to the limit set by the Paris Agreement. However, a wide range of estimates for the remaining carbon budget has been reported, reducing the effectiveness of the remaining carbon budget as a means of setting emission reduction targets that are consistent with the Paris Agreement. Here we present a framework that enables us to track estimates of the remaining carbon budget and to understand how these estimates can improve over time as scientific knowledge advances. We propose that application of this framework may help to reconcile differences between estimates of the remaining carbon budget and may provide a basis for reducing uncertainty in the range of future estimates.},
author = {Rogelj, Joeri and Forster, Piers M. and Kriegler, Elmar and Smith, Christopher J. and S{\'{e}}f{\'{e}}rian, Roland},
doi = {10.1038/s41586-019-1368-z},
issn = {0028-0836},
journal = {Nature},
keywords = {Climate,Climate change,Climate sciences,change mitigation},
month = {jul},
number = {7765},
pages = {335--342},
publisher = {Nature Publishing Group},
title = {{Estimating and tracking the remaining carbon budget for stringent climate targets}},
url = {http://www.nature.com/articles/s41586-019-1368-z},
volume = {571},
year = {2019}
}
@article{Rogers2019,
abstract = {Coastal wetlands (mangrove, tidal marsh and seagrass) sustain the highest rates of carbon sequestration per unit area of all natural systems1,2, primarily because of their comparatively high productivity and preservation of organic carbon within sedimentary substrates3. Climate change and associated relative sea-level rise (RSLR) have been proposed to increase the rate of organic-carbon burial in coastal wetlands in the first half of the twenty-first century4, but these carbon–climate feedback effects have been modelled to diminish over time as wetlands are increasingly submerged and carbon stores become compromised by erosion4,5. Here we show that tidal marshes on coastlines that experienced rapid RSLR over the past few millennia (in the late Holocene, from about 4,200 years ago to the present) have on average 1.7 to 3.7 times higher soil carbon concentrations within 20 centimetres of the surface than those subject to a long period of sea-level stability. This disparity increases with depth, with soil carbon concentrations reduced by a factor of 4.9 to 9.1 at depths of 50 to 100 centimetres. We analyse the response of a wetland exposed to recent rapid RSLR following subsidence associated with pillar collapse in an underlying mine and demonstrate that the gain in carbon accumulation and elevation is proportional to the accommodation space (that is, the space available for mineral and organic material accumulation) created by RSLR. Our results suggest that coastal wetlands characteristic of tectonically stable coastlines have lower carbon storage owing to a lack of accommodation space and that carbon sequestration increases according to the vertical and lateral accommodation space6 created by RSLR. Such wetlands will provide long-term mitigating feedback effects that are relevant to global climate–carbon modelling.},
author = {Rogers, Kerrylee and Kelleway, Jeffrey J and Saintilan, Neil and Megonigal, J Patrick and Adams, Janine B and Holmquist, James R and Lu, Meng and Schile-Beers, Lisa and Zawadzki, Atun and Mazumder, Debashish and Woodroffe, Colin D},
doi = {10.1038/s41586-019-0951-7},
issn = {0028-0836},
journal = {Nature},
month = {mar},
number = {7746},
pages = {91--95},
title = {{Wetland carbon storage controlled by millennial-scale variation in relative sea-level rise}},
url = {https://doi.org/10.1038/s41586-019-0951-7 http://www.nature.com/articles/s41586-019-0951-7},
volume = {567},
year = {2019}
}
@article{Ronge2016,
abstract = {During the last deglaciation, the opposing patterns of atmospheric CO 2 and radiocarbon activities ($\Delta$ 14 C) suggest the release of 14 C-depleted CO 2 from old carbon reservoirs. Although evidences point to the deep Pacific as a major reservoir of this 14 C-depleted carbon, its extent and evolution still need to be constrained. Here we use sediment cores retrieved along a South Pacific transect to reconstruct the spatio-temporal evolution of $\Delta$ 14 C over the last 30,000 years. In ∼2,500–3,600 m water depth, we find 14 C-depleted deep waters with a maximum glacial offset to atmospheric 14 C ($\Delta$$\Delta$ 14 C=−1,000‰). Using a box model, we test the hypothesis that these low values might have been caused by an interaction of aging and hydrothermal CO 2 influx. We observe a rejuvenation of circumpolar deep waters synchronous and potentially contributing to the initial deglacial rise in atmospheric CO 2 . These findings constrain parts of the glacial carbon pool to the deep South Pacific.},
author = {Ronge, T. A. and Tiedemann, R. and Lamy, F. and K{\"{o}}hler, P. and Alloway, B. V. and {De Pol-Holz}, R. and Pahnke, K. and Southon, J. and Wacker, L.},
doi = {10.1038/ncomms11487},
issn = {2041-1723},
journal = {Nature Communications},
month = {sep},
number = {1},
pages = {11487},
title = {{Radiocarbon constraints on the extent and evolution of the South Pacific glacial carbon pool}},
url = {http://www.nature.com/articles/ncomms11487},
volume = {7},
year = {2016}
}
@article{Ronge2020,
abstract = {It is widely assumed that the ventilation of the Southern Ocean played a crucial role in driving glacial-interglacial atmospheric CO2 levels. So far, however, ventilation records from the Indian sector of the Southern Ocean are widely missing. Here we present reconstructions of water residence times (depicted as $\Delta$$\Delta$14C and $\Delta$$\delta$13C) for the last 32,000 years on sediment records from the Kerguelen Plateau and the Conrad Rise ({\~{}}570- to 2,500-m water depth), along with simulated changes in ocean stratification from a transient climate model experiment. Our data indicate that Circumpolar Deep Waters in the Indian Ocean were part of the glacial carbon pool. At our sites, close to or bathed by upwelling deep waters, we find two pulses of decreasing $\Delta$$\Delta$14C and $\delta$13C values ({\~{}}21–17 ka; {\~{}}15–12 ka). Both transient pulses precede a similar pattern in downstream intermediate waters in the tropical Indian Ocean as well as rising atmospheric CO2 values. These findings suggest that 14C-depleted, CO2-rich Circumpolar Deep Water from the Indian Ocean contributed to the rise in atmospheric CO2 during Heinrich Stadial 1 and also the Younger Dryas and that the southern Indian Ocean acted as a gateway for sequestered carbon to the atmosphere and tropical intermediate waters.},
author = {Ronge, Thomas A. and Prange, Matthias and Mollenhauer, Gesine and Ellinghausen, Maret and Kuhn, Gerhard and Tiedemann, Ralf},
doi = {10.1029/2019PA003733},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
keywords = {Indian Ocean,Southern Ocean,Younger Dryas,carbon cycle,radiocarbon,ventilation},
month = {mar},
number = {3},
pages = {e2019PA003733},
title = {{Radiocarbon Evidence for the Contribution of the Southern Indian Ocean to the Evolution of Atmospheric CO2 Over the Last 32,000 Years}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019PA003733},
volume = {35},
year = {2020}
}
@article{Roobaert2018,
abstract = {Abstract. The calculation of the air–water CO2 exchange (FCO2) in the ocean not only depends on the gradient in CO2 partial pressure at the air–water interface but also on the parameterization of the gas exchange transfer velocity (k) and the choice of wind product. Here, we present regional and global-scale quantifications of the uncertainty in FCO2 induced by several widely used k formulations and four wind speed data products (CCMP, ERA, NCEP1 and NCEP2). The analysis is performed at a 1° × 1° resolution using the sea surface pCO2 climatology generated by Landsch{\"{u}}tzer et al. (2015a) for the 1991–2011 period, while the regional assessment relies on the segmentation proposed by the Regional Carbon Cycle Assessment and Processes (RECCAP) project. First, we use k formulations derived from the global 14C inventory relying on a quadratic relationship between k and wind speed (k = c ⋅ U102; Sweeney et al., 2007; Takahashi et al., 2009; Wanninkhof, 2014), where c is a calibration coefficient and U10 is the wind speed measured 10m above the surface. Our results show that the range of global FCO2, calculated with these k relationships, diverge by 12{\%} when using CCMP, ERA or NCEP1. Due to differences in the regional wind patterns, regional discrepancies in FCO2 are more pronounced than global. These global and regional differences significantly increase when using NCEP2 or other k formulations which include earlier relationships (i.e., Wanninkhof, 1992; Wanninkhof et al., 2009) as well as numerous local and regional parameterizations derived experimentally. To minimize uncertainties associated with the choice of wind product, it is possible to recalculate the coefficient c globally (hereafter called c∗) for a given wind product and its spatio-temporal resolution, in order to match the last evaluation of the global k value. We thus performed these recalculations for each wind product at the resolution and time period of our study but the resulting global FCO2 estimates still diverge by 10{\%}. These results also reveal that the Equatorial Pacific, the North Atlantic and the Southern Ocean are the regions in which the choice of wind product will most strongly affect the estimation of the FCO2, even when using c∗.},
author = {Roobaert, Aliz{\'{e}}e and Laruelle, Goulven G. and Landsch{\"{u}}tzer, Peter and Regnier, Pierre},
doi = {10.5194/bg-15-1701-2018},
issn = {1726-4189},
journal = {Biogeosciences},
month = {mar},
number = {6},
pages = {1701--1720},
title = {{Uncertainty in the global oceanic CO2 uptake induced by wind forcing: quantification and spatial analysis}},
url = {https://www.biogeosciences.net/15/1701/2018/},
volume = {15},
year = {2018}
}
@article{Roobaert2019,
abstract = {Abstract In contrast to the open ocean, the sources and sinks for atmospheric carbon dioxide (CO2) in the coastal seas are poorly constrained and understood. Here, we address this knowledge gap by analyzing the spatial and temporal variability of the coastal air-sea flux of CO2 (FCO2) using a recent high-resolution (0.25 degree) monthly climatology for coastal sea surface partial pressure in CO2 (pCO2). Coastal regions are characterized by CO2 sinks at temperate and high latitudes and by CO2 sources at low latitude and in the tropics, with annual mean CO2 flux densities comparable in magnitude and pattern to those of the adjacent open ocean with the exception of river dominated systems. The seasonal variations in FCO2 are large, often exceeding 2 mol C m-2 yr-1, a magnitude similar to the variations exhibited across latitudes. The majority of these seasonal variations stems from the air-sea pCO2 difference, although changes in wind speed and sea-ice cover can also be significant regionally. Globally integrated, the coastal seas act currently as a CO2 sink of -0.20 ± 0.02 Pg C yr-1, with a more intense uptake occurring in summer because of the disproportionate influence of high latitude shelves in the Northern Hemisphere. Combined with estimates of the carbon sinks in the open ocean and the Arctic, this gives for the global ocean, averaged over the 1998 to 2015 period an annual net CO2 uptake of -1.7 ± 0.3 Pg C yr-1.},
annote = {From Duplicate 1 (The spatiotemporal dynamics of the sources and sinks of CO 2 in the global coastal ocean - Roobaert, Aliz{\'{e}}e; Laruelle, Goulven G; Landsch{\"{u}}tzer, Peter; Gruber, Nicolas; Chou, Lei; Regnier, Pierre)
And Duplicate 2 (The spatiotemporal dynamics of the sources and sinks of CO 2 in the global coastal ocean - Roobaert, Aliz{\'{e}}e; Laruelle, Goulven G; Landsch{\"{u}}tzer, Peter; Gruber, Nicolas; Chou, Lei; Regnier, Pierre)

doi: 10.1029/2019GB006239

From Duplicate 3 (The spatiotemporal dynamics of the sources and sinks of CO2 in the global coastal ocean - Roobaert, Aliz{\'{e}}e; Laruelle, Goulven G; Landsch{\"{u}}tzer, Peter; Gruber, Nicolas; Chou, Lei; Regnier, Pierre)

From Duplicate 1 (The Spatiotemporal Dynamics of the Sources and Sinks of CO 2 in the Global Coastal Ocean - Roobaert, Aliz{\'{e}}e; Laruelle, Goulven G; Landsch{\"{u}}tzer, Peter; Gruber, Nicolas; Chou, Lei; Regnier, Pierre)

doi: 10.1029/2019GB006239},
author = {Roobaert, Aliz{\'{e}}e and Laruelle, Goulven G and Landsch{\"{u}}tzer, Peter and Gruber, Nicolas and Chou, Lei and Regnier, Pierre},
doi = {10.1029/2019GB006239},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {air-sea CO2 exchange,coastal seas,continental shelves,ocean carbon cycle,seasonality},
month = {dec},
number = {12},
pages = {2019GB006239},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{The spatiotemporal dynamics of the sources and sinks of CO2 in the global coastal ocean}},
url = {https://doi.org/10.1029/2019GB006239 https://onlinelibrary.wiley.com/doi/abs/10.1029/2019GB006239},
volume = {33},
year = {2019}
}
@article{Rosa2020,
abstract = {Carbon capture and storage (CCS) is a strategy to mitigate climate change by limiting CO2 emissions from point sources such as coal-fired power plants (CFPPs). Although decision-makers are seeking to implement policies regarding CCS, the consequences of this technology on water scarcity have not been fully assessed. Here we simulate the impacts on water resources that would result from retrofitting global CFPPs with four different CCS technologies. We find that 43{\%} of the global CFPP capacity experiences water scarcity for at least one month per year and 32{\%} experiences scarcity for five or more months per year. Although retrofitting CFPPs with CCS would not greatly exacerbate water scarcity, we show that certain geographies lack sufficient water resources to meet the additional water demands of CCS technologies. For CFPPs located in these water-scarce areas, the trade-offs between the climate change mitigation benefits and the increased pressure on water resources of CCS should be weighed. We conclude that CCS should be preferentially deployed at those facilities least impacted by water scarcity.},
author = {Rosa, Lorenzo and Reimer, Jeffrey A. and Went, Marjorie S. and D'Odorico, Paolo},
doi = {10.1038/s41893-020-0532-7},
issn = {23989629},
journal = {Nature Sustainability},
number = {8},
pages = {658--666},
publisher = {Springer US},
title = {{Hydrological limits to carbon capture and storage}},
url = {http://dx.doi.org/10.1038/s41893-020-0532-7},
volume = {3},
year = {2020}
}
@article{Rosentreter2018,
abstract = {Organic matter burial in mangrove forests results in the removal and long-term storage of atmospheric CO2, so-called “blue carbon.” However, some of this organic matter is metabolized and returned to the atmosphere as CH4. Because CH4 has a higher global warming potential than the CO2 fixed in the organic matter, it can offset the CO2 removed via carbon burial. We provide the first estimate of the global magnitude of this offset. Our results show that high CH4 evasion rates have the potential to partially offset blue carbon burial rates in mangrove sediments on average by 20{\%} (sensitivity analysis offset range, 18 to 22{\%}) using the 20-year global warming potential. Hence, mangrove sediment and water CH4 emissions should be accounted for in future blue carbon assessments.},
author = {Rosentreter, Judith A. and Maher, Damien T. and Erler, Dirk V. and Murray, Rachel H. and Eyre, Bradley D.},
doi = {10.1126/sciadv.aao4985},
issn = {2375-2548},
journal = {Science Advances},
month = {jun},
number = {6},
pages = {eaao4985},
publisher = {American Association for the Advancement of Science},
title = {{Methane emissions partially offset “blue carbon” burial in mangroves}},
url = {http://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aao4985},
volume = {4},
year = {2018}
}
@article{Roshan2017,
author = {Roshan, Saeed and DeVries, Timothy},
doi = {10.1038/s41467-017-02227-3},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {2036},
title = {{Efficient dissolved organic carbon production and export in the oligotrophic ocean}},
url = {http://www.nature.com/articles/s41467-017-02227-3},
volume = {8},
year = {2017}
}
@article{Ross2020,
abstract = {Abstract Anthropogenic climate change is causing our oceans to lose oxygen and become more acidic at an unprecedented rate, threatening marine ecosystems and their associated animals. In deep-sea environments, where conditions have typically changed over geological timescales, the associated animals, adapted to these stable conditions, are expected to be highly vulnerable to any change or direct human impact. Our study coalesces one of the longest deep-sea observational oceanographic time series, reaching back to the 1960s, with a modern visual survey that characterizes almost two vertical kilometers of benthic seamount ecosystems. Based on our new and rigorous analysis of the Line P oceanographic monitoring data, the upper 3,000 m of the Northeast Pacific (NEP) has lost 15{\%} of its oxygen in the last 60 years. Over that time, the oxygen minimum zone (OMZ), ranging between approximately 480 and 1,700 m, has expanded at a rate of 3.0 ± 0.7 m/year (due to deepening at the bottom). Additionally, carbonate saturation horizons above the OMZ have been shoaling at a rate of 1?2 m/year since the 1980s. Based on our visual surveys of four NEP seamounts, these deep-sea features support ecologically important taxa typified by long life spans, slow growth rates, and limited mobility, including habitat-forming cold water corals and sponges, echinoderms, and fish. By examining the changing conditions within the narrow realized bathymetric niches for a subset of vulnerable populations, we resolve chemical trends that are rapid in comparison to the life span of the taxa and detrimental to their survival. If these trends continue as they have over the last three to six decades, they threaten to diminish regional seamount ecosystem diversity and cause local extinctions. This study highlights the importance of mitigating direct human impacts as species continue to suffer environmental changes beyond our immediate control.},
author = {Ross, Tetjana and {Du Preez}, Cherisse and Ianson, Debby},
doi = {10.1111/gcb.15307},
issn = {1354-1013},
journal = {Global Change Biology},
keywords = {benthic ecosystems,climate change,cold water corals,ecosystem-based management,ocean acidification,ocean biogeochemistry,ocean deoxygenation,vulnerable marine ecosystems},
month = {nov},
number = {11},
pages = {6424--6444},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Rapid deep ocean deoxygenation and acidification threaten life on Northeast Pacific seamounts}},
url = {https://doi.org/10.1111/gcb.15307 https://onlinelibrary.wiley.com/doi/10.1111/gcb.15307},
volume = {26},
year = {2020}
}
@article{Roth2012,
author = {Roth, Raphael and Joos, Fortunat},
doi = {10.1016/j.epsl.2012.02.019},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
month = {may},
pages = {141--149},
title = {{Model limits on the role of volcanic carbon emissions in regulating glacial–interglacial CO2 variations}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X12001094},
volume = {329-330},
year = {2012}
}
@incollection{IPCC2018,
author = {Roy, J. and Tschakert, P. and Waisman, H. and {Abdul Halim}, S. and Antwi-Agyei, P. and Dasgupta, P. and Hayward, B. and Kanninen, M. and Liverman, D. and Okereke, C. and Pinho, P.F. and Riahi, K. and {Suarez Rodriguez}, A.G.},
booktitle = {Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change,},
chapter = {5},
editor = {Masson-Delmotte, V. and Zhai, P. and P{\"{o}}rtner, H.-O. and Roberts, D. and Skea, J. and Shukla, P.R. and Pirani, A. and Moufouma-Okia, W. and P{\'{e}}an, C. and Pidcock, R. and Connors, S. and Matthews, J.B.R. and Chen, Y. and Zhou, X. and Gomis, M.I. and Lonnoy, E. and Maycock, T. and Tignor, M. and Waterfield, T.},
pages = {445--538},
publisher = {In Press},
title = {{Sustainable Development, Poverty Eradication and Reducing Inequalities}},
url = {https://www.ipcc.ch/sr15/chapter/chapter-5},
year = {2018}
}
@article{Roy2011,
abstract = {The increase in atmospheric CO2 over this century depends on the evolution of the oceanic air-sea CO2 uptake, which will be driven by the combined response to rising atmospheric CO2 itself and climate change. Here, the future oceanic CO2 uptake is simulated using an ensemble of coupled climate-carbon cycle models. The models are driven by CO2 emissions from historical data and the Special Report on Emissions Scenarios (SRES) A2 high-emission scenario. A linear feedback analysis successfully separates the regional future (2010-2100) oceanic CO2 uptake into a CO2-induced component, due to rising atmospheric CO2 concentrations, and a climate-induced component, due to global warming. The models capture the observationbased magnitude and distribution of anthropogenic CO2 uptake. The distributions of the climate-induced component are broadly consistent between the models, with reduced CO2 uptake in the subpolar Southern Ocean and the equatorial regions, owing to decreased CO2 solubility; and reduced CO2 uptake in the midlatitudes, owing to decreased CO2 solubility and increased vertical stratification. The magnitude of the climate-induced component is sensitive to local warming in the southern extratropics, to large freshwater fluxes in the extratropical North Atlantic Ocean, and to small changes in the CO2 solubility in the equatorial regions. In key anthropogenic CO2 uptake regions, the climate-induced component offsets the CO2-induced component at a constant proportion up until the end of this century. This amounts to approximately 50{\%} in the northern extratropics and 25{\%} in the southern extratropics and equatorial regions. Consequently, the detection of climate change impacts on anthropogenic CO2 uptake may be difficult without monitoring additional tracers, such as oxygen. {\textcopyright} 2011 American Meteorological Society.},
author = {Roy, Tilla and Bopp, Laurent and Gehlen, Marion and Schneider, Birgit and Cadule, Patricia and Fr{\"{o}}licher, Thomas L. and Segschneider, Joachim and Tjiputra, Jerry and Heinze, Christoph and Joos, Fortunat},
doi = {10.1175/2010JCLI3787.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Carbon dioxide,Climate change,Feedback,Ocean models,Regional effects},
month = {may},
number = {9},
pages = {2300--2318},
publisher = {American Meteorological Society},
title = {{Regional impacts of climate change and atmospheric CO2 on future ocean carbon uptake: A multimodel linear feedback analysis}},
url = {http://cmip-pcmdi.},
volume = {24},
year = {2011}
}
@article{Roy2016,
abstract = {Extreme climatic events (ECEs) such as droughts and heat waves are predicted to increase in intensity and frequency and impact the terrestrial carbon balance. However, we lack direct experimental evidence of how the net carbon uptake of ecosystems is affected by ECEs under future elevated atmospheric CO2 concentrations (eCO2). Taking advantage of an advanced controlled environment facility for ecosystem research (Ecotron), we simulated eCO2 and extreme cooccurring heat and drought events as projected for the 2050s and analyzed their effects on the ecosystem-level carbon and water fluxes in a C3 grassland. Our results indicate that eCO2 not only slows down the decline of ecosystem carbon uptake during the ECE but also enhances its recovery after the ECE, as mediated by increases of root growth and plant nitrogen uptake induced by the ECE. These findings indicate that, in the predicted near future climate, eCO2 could mitigate the effects of extreme droughts and heat waves on ecosystem net carbon uptake.},
author = {Roy, Jacques and Picon-Cochard, Catherine and Augusti, Angela and Benot, Marie Lise and Thiery, Lionel and Darsonville, Olivier and Landais, Damien and Piel, Cl{\'{e}}ment and Defossez, Marc and Devidal, S{\'{e}}bastien and Escape, Christophe and Ravel, Olivier and Fromin, Nathalie and Volaire, Florence and Milcu, Alexandru and Bahn, Michael and Soussana, Jean Fran{\c{c}}ois},
doi = {10.1073/pnas.1524527113},
issn = {10916490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Carbon fluxes,Climate change,Elevated CO2,Extreme events,Grassland ecosystem},
number = {22},
pages = {6224--6229},
pmid = {27185934},
title = {{Elevated CO2 maintains grassland net carbon uptake under a future heat and drought extreme}},
volume = {113},
year = {2016}
}
@article{Royer2016a,
author = {Royer, S.-J. and Gal{\'{i}}, M and Mahajan, A S and Ross, O N and P{\'{e}}rez, G L and Saltzman, E S and Sim{\'{o}}, R},
doi = {10.1038/srep32325},
issn = {2045-2322},
journal = {Scientific Reports},
month = {aug},
pages = {32325},
publisher = {The Author(s)},
title = {{A high-resolution time-depth view of dimethylsulphide cycling in the surface sea}},
volume = {6},
year = {2016}
}
@article{Rubino2013,
abstract = {We present new measurements of $\delta$13C of CO2 extracted from a high-resolution ice core from Law Dome (East Antarctica), together with firn measurements performed at Law Dome and South Pole, covering the last 150 years. Our analysis is motivated by the need to better understand the role and feedback of the carbon (C) cycle in climate change, by advances in measurement methods, and by apparent anomalies when comparing ice core and firn air $\delta$13C records from Law Dome and South Pole. We demonstrate improved consistency between Law Dome ice, South Pole firn, and the Cape Grim (Tasmania) atmospheric $\delta$13C data, providing evidence that our new record reliably extends direct atmospheric measurements back in time. We also show a revised version of early $\delta$13C measurements covering the last 1000 years, with a mean preindustrial level of -6.50‰. Finally, we use a Kalman Filter Double Deconvolution to infer net natural CO2 fluxes between atmosphere, ocean, and land, which cause small $\delta$13C deviations from the predominant anthropogenically induced $\delta$13C decrease. The main features found from the previous $\delta$13C record are confirmed, including the ocean as the dominant cause for the 1940 A.D. CO2 leveling. Our new record provides a solid basis for future investigation of the causes of decadal to centennial variations of the preindustrial atmospheric CO2 concentration. Those causes are of potential significance for predicting future CO2 levels and when attempting atmospheric verification of recent and future global carbon emission mitigation measures through Coupled Climate Carbon Cycle Models. Key Points New and revised, firn and ice $\delta$13C-CO2 measurements from Antarctica Improve consistency between ice and firn $\delta$13C-CO2 measurements Net natural CO2 fluxes between atmosphere, ocean and land inferred {\textcopyright}2013. American Geophysical Union. All Rights Reserved.},
author = {Rubino, M. and Etheridge, D. M. and Trudinger, C. M. and Allison, C. E. and Battle, M. O. and Langenfelds, R. L. and Steele, L. P. and Curran, M. and Bender, M. and White, J. W. C. and Jenk, T. M. and Blunier, T. and Francey, R. J.},
doi = {10.1002/jgrd.50668},
isbn = {2169897X},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
keywords = {Antarctica,carbon stable isotopes,global carbon cycle,ice cores},
month = {aug},
number = {15},
pages = {8482--8499},
title = {{A revised 1000 year atmospheric $\delta$13C-CO2 record from Law Dome and South Pole, Antarctica}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/jgrd.50668 http://doi.wiley.com/10.1002/jgrd.50668},
volume = {118},
year = {2013}
}
@article{Ruddiman2015,
author = {Ruddiman, W F and Fuller, D Q and Kutzbach, J E and Tzedakis, P C and Kaplan, J O and Ellis, E C and Vavrus, S J and Roberts, C N and Fyfe, R and He, F and Lemmen, C and Woodbridge, J},
doi = {10.1002/2015RG000503},
issn = {87551209},
journal = {Reviews of Geophysics},
keywords = {10.1002/2015RG000503 and anthropogenic,Holocene,climate},
month = {mar},
number = {1},
pages = {93--118},
title = {{Late Holocene climate: Natural or anthropogenic?}},
url = {http://doi.wiley.com/10.1002/2015RG000503},
volume = {54},
year = {2016}
}
@article{Ruppel2017a,
abstract = {Gas hydrate, a frozen, naturally-occurring and highly-concentrated form of methane, sequesters significant carbon in the global system and is stable only over a range of low-temperature and moderate-pressure conditions. Gas hydrate is widespread in the sediments of marine continental margins and permafrost areas, locations where ocean and atmospheric warming may perturb the hydrate stability field and lead to release of the sequestered methane into the overlying sediments and soils. Methane and methane-derived carbon that escape from sediments and soils and reach the atmosphere could exacerbate greenhouse warming. The synergy between warming climate and gas hydrate dissociation feeds a popular perception that global warming could drive catastrophic methane releases from the contemporary gas hydrate reservoir. Appropriate evaluation of the two sides of the climate-methane hydrate synergy requires assessing direct and indirect observational data related to gas hydrate dissociation phenomena and numerical models that track the interaction of gas hydrates/methane with the ocean and/or atmosphere. Methane hydrate is likely undergoing dissociation now on global upper continental slopes and on continental shelves that ring the Arctic Ocean. Many factors--the depth of the gas hydrates in sediments, strong sediment and water column sinks, and the inability of bubbles emitted at the seafloor to deliver methane to the sea-air interface in most cases--mitigate the impact of gas hydrate dissociation on atmospheric greenhouse gas concentrations though. There is no conclusive proof that hydrate-derived methane is reaching the atmosphere now, but more observational data and improved numerical models will better characterize the climate-hydrate synergy in the future.},
author = {Ruppel, Carolyn D. and Kessler, John D.},
doi = {10.1002/2016RG000534},
isbn = {8755-1209},
issn = {87551209},
journal = {Reviews of Geophysics},
month = {mar},
number = {1},
pages = {126--168},
title = {{The interaction of climate change and methane hydrates}},
url = {http://doi.wiley.com/10.1002/2016RG000534},
volume = {55},
year = {2017}
}
@article{doi:10.1021/je500770m,
author = {Ruppel, C D},
doi = {10.1021/je500770m},
journal = {Journal of Chemical {\&} Engineering Data},
number = {2},
pages = {429--436},
title = {{Permafrost-Associated Gas Hydrate: Is It Really Approximately 1{\%} of the Global System?}},
url = {https://doi.org/10.1021/je500770m},
volume = {60},
year = {2015}
}
@article{Seferian2018,
abstract = {The decadal predictability of carbon fluxes has been examined over continents and oceans using a “perfect model” approach based on a 400 year preindustrial simulation and five 10-member ensembles from the Centre National de Recherches M{\'{e}}t{\'{e}}orologiques-Earth System Model version 1. From these experiments, we find that the global land uptake and ocean carbon uptake are potentially predictable by up to six years, with a median predictability horizon of four years. Predictability of global carbon uptake is prominently driven by the ocean's predictability. The difference in predictability between ocean and land carbon fluxes stems from the relative capability of ocean or land to generate low-frequency fluctuations in carbon flux. Indeed, ocean carbon fluxes display low-frequency variability that emerges from the year-to-year variability in the North Atlantic, the North Pacific, and the Southern Ocean. The Southern Ocean carbon uptake can be predicted up to six years in advance and explains most of the global carbon uptake predictability.},
author = {S{\'{e}}f{\'{e}}rian, Roland and Berthet, Sarah and Chevallier, Matthieu},
doi = {10.1002/2017GL076092},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Earth system model,carbon fluxes,decadal predictability,internal variability},
month = {mar},
number = {5},
pages = {2455--2466},
title = {{Assessing the decadal predictability of land and ocean carbon uptake}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/2017GL076092},
volume = {45},
year = {2018}
}
@article{Seferian2014,
abstract = {With the emergence of decadal predictability simulations, research toward forecasting variations of the climate system now covers a large range of timescales. However, assessment of the capacity to predict natural variations of relevant biogeochemical variables like carbon fluxes, pH, or marine primary productivity remains unexplored. Among these, the net primary productivity (NPP) is of particular relevance in a forecasting perspective. Indeed, in regions like the tropical Pacific (30°N-30°S), NPP exhibits natural fluctuations at interannual to decadal timescales that have large impacts on marine ecosystems and fisheries. Here, we investigate predictions of NPP variations over the last decades (i.e., from 1997 to 2011) with an Earth system model within the tropical Pacific. Results suggest a predictive skill for NPP of 3 y, which is higher than that of sea surface temperature (1 y). We attribute the higher predictability of NPP to the poleward advection of nutrient anomalies (nitrate and iron), which sustain fluctuations in phytoplankton productivity over several years. These results open previously unidentified perspectives to the development of science-based management approaches to marine resources relying on integrated physical-biogeochemical forecasting systems.},
author = {S{\'{e}}f{\'{e}}rian, Roland and Bopp, Laurent and Gehlen, Marion and Swingedouw, Didier and Mignot, Juliette and Guilyardi, Eric and Servonnat, J{\'{e}}r{\^{o}}me},
doi = {10.1073/pnas.1315855111},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Ecosystem management,Forecast,Marine biogeochemistry},
month = {aug},
number = {32},
pages = {11646--11651},
title = {{Multiyear predictability of tropical marine productivity}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1315855111},
volume = {111},
year = {2014}
}
@article{Seferian2020,
abstract = {The changes or updates in ocean biogeochemistry component have been mapped between CMIP5 and CMIP6 model versions, and an assessment made of how far these have led to improvements in the simulated mean state of marine biogeochemical models within the current generation of Earth system models (ESMs).},
author = {S{\'{e}}f{\'{e}}rian, Roland and Berthet, Sarah and Yool, Andrew and Palmi{\'{e}}ri, Julien and Bopp, Laurent and Tagliabue, Alessandro and Kwiatkowski, Lester and Aumont, Olivier and Christian, James and Dunne, John and Gehlen, Marion and Ilyina, Tatiana and John, Jasmin G and Li, Hongmei and Long, Matthew C and Luo, Jessica Y and Nakano, Hideyuki and Romanou, Anastasia and Schwinger, J{\"{o}}rg and Stock, Charles and Santana-Falc{\'{o}}n, Yeray and Takano, Yohei and Tjiputra, Jerry and Tsujino, Hiroyuki and Watanabe, Michio and Wu, Tongwen and Wu, Fanghua and Yamamoto, Akitomo},
doi = {10.1007/s40641-020-00160-0},
issn = {2198-6061},
journal = {Current Climate Change Reports},
number = {3},
pages = {95--119},
title = {{Tracking Improvement in Simulated Marine Biogeochemistry Between CMIP5 and CMIP6}},
url = {https://doi.org/10.1007/s40641-020-00160-0},
volume = {6},
year = {2020}
}
@article{Seferian2018a,
abstract = {To limit global warming to well below 2 ° most of the IPCC-WGIII future stringent mitigation pathways feature a massive global-scale deployment of negative emissions technologies (NETs) before the end of the century. The global-scale deployment of NETs like Biomass Energy with Carbon Capture and Storage (BECCS) can be hampered by climate constraints that are not taken into account by Integrated assessment models (IAMs) used to produce those pathways. Among the various climate constraints, water scarcity appears as a potential bottleneck for future land-based mitigation strategies and remains largely unexplored. Here, we assess climate constraints relative to water scarcity in response to the global deployment of BECCS. To this end, we confront results from an Earth system model (ESM) and an IAM under an array of 25 stringent mitigation pathways. These pathways are compatible with the Paris Agreement long-term temperature goal and with cumulative carbon emissions ranging from 230 Pg C and 300 Pg C from January 1st onwards. We show that all stylized mitigation pathways studied in this work limit warming below 2 °C or even 1.5 °C by 2100 but all exhibit a temperature overshoot exceeding 2 °C after 2050. According to the IAM, a subset of 17 emission pathways are feasible when evaluated in terms of socio-economic and technological constraints. The ESM however shows that water scarcity would limit the deployment of BECCS in all the mitigation pathways assessed in this work. Our findings suggest that the evolution of the water resources under climate change can exert a significant constraint on BECCS deployment before 2050. In 2100, the BECCS water needs could represent more than 30{\%} of the total precipitation in several regions like Europe or Asia.},
author = {S{\'{e}}f{\'{e}}rian, Roland and Rocher, Matthias and Guivarch, C{\'{e}}line and Colin, Jeanne},
doi = {10.1088/1748-9326/aabcd7},
issn = {17489326},
journal = {Environmental Research Letters},
keywords = {bioenergy,climate change,earthsystemmodelling,hydrological cycle,integratedassessmentmodel,mitigation options,negative emissions},
number = {5},
pages = {054011},
title = {{Constraints on biomass energy deployment in mitigation pathways: The case of water scarcity}},
volume = {13},
year = {2018}
}
@article{Sabine2004,
abstract = {Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 19 petagrams of carbon. The oceanic sink accounts for {\~{}}48{\%} of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential.},
author = {Sabine, Christopher L and Feely, Richard A. and Gruber, Nicolas and Key, Robert M. and Lee, Kitack and Bullister, John L. and Wanninkhof, Rik and Wong, C. S. and Wallace, Douglas W. R. and Tilbrook, Bronte and Millero, Frank J. and Peng, Tsung-Hung and Kozyr, Alexander and Ono, Tsueno and Rios, Aida F.},
doi = {10.1126/science.1097403},
issn = {0036-8075},
journal = {Science},
month = {jul},
number = {5682},
pages = {367--371},
publisher = {American Association for the Advancement of Science},
title = {{The Oceanic Sink for Anthropogenic CO2}},
url = {https://www.science.org/doi/10.1126/science.1097403},
volume = {305},
year = {2004}
}
@article{Saeki2017,
abstract = {Measurement and modelling of regional or country-level carbon dioxide (CO2) fluxes are becoming critical for verification of the greenhouse gases emission control. One of the commonly adopted approaches is inverse modelling, where CO2 fluxes (emission: positive flux, sink: negative flux) from the terrestrial ecosystems are estimated by combining atmospheric CO2 measurements with atmospheric transport models. The inverse models assume anthropogenic emissions are known, and thus the uncertainties in the emissions introduce systematic bias in estimation of the terrestrial (residual) fluxes by inverse modelling. Here we show that the CO2 sink increase, estimated by the inverse model, over East Asia (China, Japan, Korea and Mongolia), by about 0.26 PgC year−1 (1 Pg = 1012 g) during 2001–2010, is likely to be an artifact of the anthropogenic CO2 emissions increasing too quickly in China by 1.41 PgC year−1. Independent results from methane (CH4) inversion suggested about 41{\%} lower rate of East Asian CH4 emission increase during 2002–2012. We apply a scaling factor of 0.59, based on CH4 inversion, to the rate of anthropogenic CO2 emission increase since the anthropogenic emissions of both CO2 and CH4 increase linearly in the emission inventory. We find no systematic increase in land CO2 uptake over East Asia during 1993–2010 or 2000–2009 when scaled anthropogenic CO2 emissions are used, and that there is a need of higher emission increase rate for 2010–2012 compared to those calculated by the inventory methods. High bias in anthropogenic CO2 emissions leads to stronger land sinks in global land–ocean flux partitioning in our inverse model. The corrected anthropogenic CO2 emissions also produce measurable reductions in the rate of global land CO2 sink increase post-2002, leading to a better agreement with the terrestrial biospheric model simulations that include CO2-fertilization and climate effects.},
author = {Saeki, Tazu and Patra, Prabir K.},
doi = {10.1186/s40562-017-0074-7},
issn = {2196-4092},
journal = {Geoscience Letters},
month = {dec},
number = {1},
pages = {9},
publisher = {Springer International Publishing},
title = {{Implications of overestimated anthropogenic CO2 emissions on East Asian and global land CO2 flux inversion}},
url = {http://geoscienceletters.springeropen.com/articles/10.1186/s40562-017-0074-7},
volume = {4},
year = {2017}
}
@article{Saikawa2014,
abstract = {We present a comprehensive estimate of nitrous oxide (N2O) emissions using observations and models from 1995 to 2008. High-frequency records of tropospheric N2O are available from measurements at Cape Grim, Tasmania; Cape Matatula, American Samoa; Ragged Point, Barbados; Mace Head, Ireland; and at Trinidad Head, California using the Advanced Global Atmospheric Gases Experiment (AGAGE) instrumentation and calibrations. The Global Monitoring Division of the National Oceanic and Atmospheric Administration/Earth System Research Laboratory (NOAA/ESRL) has also collected discrete air samples in flasks and in situ measurements from remote sites across the globe and analyzed them for a suite of species including N2O. In addition to these major networks, we include in situ and aircraft measurements from the National Institute of Environmental Studies (NIES) and flask measurements from the Tohoku University and Commonwealth Scientific and Industrial Research Organization (CSIRO) networks. All measurements show increasing atmospheric mole fractions of N2O, with a varying growth rate of 0.1-0.7{\%} per year, resulting in a 7.4{\%} increase in the background atmospheric mole fraction between 1979 and 2011. Using existing emission inventories as well as bottom-up process modeling results, we first create globally gridded a priori N2O emissions over the 37 years since 1975. We then use the three-dimensional chemical transport model, Model for Ozone and Related Chemical Tracers version 4 (MOZART v4), and a Bayesian inverse method to estimate global as well as regional annual emissions for five source sectors from 13 regions in the world. This is the first time that all of these measurements from multiple networks have been combined to determine emissions. Our inversion indicates that global and regional N2O emissions have an increasing trend between 1995 and 2008. Despite large uncertainties, a significant increase is seen from the Asian agricultural sector in recent years, most likely due to an increase in the use of nitrogenous fertilizers, as has been suggested by previous studies. Copyright {\textcopyright} 2014 by ASME.},
author = {Saikawa, E. and Prinn, R. G. and Dlugokencky, E. and Ishijima, K. and Dutton, G. S. and Hall, B. D. and Langenfelds, R. and Tohjima, Y. and Machida, T. and Manizza, M. and Rigby, M. and O'Doherty, S. and Patra, P. K. and Harth, C. M. and Weiss, R. F. and Krummel, P. B. and {Van Der Schoot}, M. and Fraser, P. J. and Steele, L. P. and Aoki, S. and Nakazawa, T. and Elkins, J. W.},
doi = {10.5194/acp-14-4617-2014},
isbn = {1680-7316},
issn = {16807324},
journal = {Atmospheric Chemistry and Physics},
number = {9},
pages = {4617--4641},
title = {{Global and regional emissions estimates for N2O}},
volume = {14},
year = {2014}
}
@article{1748-9326-11-12-124029,
abstract = {Land carbon sensitivity to atmospheric CO 2 concentration ($\beta$ L ) and climate warming ($\gamma$ L ) is a crucial part of carbon-climate feedbacks that affect the magnitude of future warming. Although these sensitivities can be estimated by earth system models, their dependence on model representation of land carbon dynamics and the inherent model assumptions has rarely been investigated. Using the widely used Community Land Model version 4 as an example, we examine how $\beta$ L and $\gamma$ L vary with prescribed versus dynamic vegetation covers. Both sensitivities are found to be larger with dynamic compared to prescribed vegetation on decadal timescale in the late twentieth century, with a more robust difference in $\gamma$ L . The latter is a result of dynamic vegetation model deficiencies in representing the competitions between deciduous versus evergreen trees and tree versus grass over the tropics and subtropics. The biased vegetation cover changes the regional characteristics of carbon-nitrogen cycles such that plant productivity responds less strongly to the enhancement of nitrogen mineralization with warming, so more carbon is lost to the atmosphere with rising temperature. The result calls for systematic evaluations of land carbon sensitivities with varying assumptions for land cover representations to help prioritize development effort and constrain uncertainties in carbon-climate feedbacks.},
annote = {added by A.Eliseev 22.01.2019},
author = {Sakaguchi, K and Zeng, X and Leung, LR and Shao, P},
doi = {10.1088/1748-9326/aa51d9},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {dec},
number = {12},
pages = {124029},
title = {{Influence of dynamic vegetation on carbon–nitrogen cycle feedback in the Community Land Model (CLM4)}},
url = {http://stacks.iop.org/1748-9326/11/i=12/a=124029 http://stacks.iop.org/1748-9326/11/i=12/a=124029?key=crossref.4843410b92ae8cc1f9117b5b50bf1c99},
volume = {11},
year = {2016}
}
@article{Sakschewski2016,
author = {Sakschewski, Boris and von Bloh, Werner and Boit, Alice and Poorter, Lourens and Pe{\~{n}}a-Claros, Marielos and Heinke, Jens and Joshi, Jasmin and Thonicke, Kirsten},
doi = {10.1038/nclimate3109},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {nov},
number = {11},
pages = {1032--1036},
publisher = {Nature Publishing Group},
title = {{Resilience of Amazon forests emerges from plant trait diversity}},
url = {https://doi.org/10.1038/nclimate3109 http://10.0.4.14/nclimate3109 https://www.nature.com/articles/nclimate3109{\#}supplementary-information http://www.nature.com/articles/nclimate3109},
volume = {6},
year = {2016}
}
@article{Salisbury2018,
abstract = {A profound warming event in the Gulf of Maine during the last decade has caused sea surface temperatures to rise to levels exceeding any earlier observations recorded in the region over the last 150 years. This event dramatically affected CO2 solubility and, in turn, the status of the sea surface carbonate system. When combined with the concomitant increase in sea surface salinity and assumed rapid equilibration of carbon dioxide across the air sea interface, thermodynamic forcing partially mitigated the effects of ocean acidification for pH, while raising the saturation index of aragonite ($\Omega$AR$\Omega$AR ) by an average of 0.14 U. Although the recent event is categorically extreme, we find that carbonate system parameters also respond to interannual and decadal variability in temperature and salinity, and that such phenomena can mask the expression of ocean acidification caused by increasing atmospheric carbon dioxide. An analysis of a 34-year salinity and SST time series (1981–2014) shows instances of 5–10 years anomalies in temperature and salinity that perturb the carbonate system to an extent greater than that expected from ocean acidification. Because such conditions are not uncommon in our time series, it is critical to understand processes controlling the carbonate system and how ecosystems with calcifying organisms respond to its rapidly changing conditions. It is also imperative that regional and global models used to estimate carbonate system trends carefully resolve variations in the physical processes that control CO2 concentrations in the surface ocean on timescales from episodic events to decades and longer.},
author = {Salisbury, Joseph E. and J{\"{o}}nsson, Bror F.},
doi = {10.1007/s10533-018-0505-3},
issn = {0168-2563},
journal = {Biogeochemistry},
month = {dec},
number = {3},
pages = {401--418},
title = {{Rapid warming and salinity changes in the Gulf of Maine alter surface ocean carbonate parameters and hide ocean acidification}},
url = {http://link.springer.com/10.1007/s10533-018-0505-3},
volume = {141},
year = {2018}
}
@article{Sallee2012,
author = {Sall{\'{e}}e, Jean-Baptiste and Matear, Richard J and Rintoul, Stephen R and Lenton, Andrew},
doi = {10.1038/ngeo1523},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {aug},
number = {8},
pages = {579--584},
publisher = {Nature Publishing Group},
title = {{Localized subduction of anthropogenic carbon dioxide in the Southern Hemisphere oceans}},
url = {http://dx.doi.org/10.1038/ngeo1523 10.1038/ngeo1523 https://www.nature.com/articles/ngeo1523{\#}supplementary-information http://www.nature.com/articles/ngeo1523},
volume = {5},
year = {2012}
}
@article{doi:10.1111/gcb.13204,
abstract = {Abstract Perennially frozen soil in high latitude ecosystems (permafrost) currently stores 1330–1580 Pg of carbon (C). As these ecosystems warm, the thaw and decomposition of permafrost is expected to release large amounts of C to the atmosphere. Fortunately, losses from the permafrost C pool will be partially offset by increased plant productivity. The degree to which plants are able to sequester C, however, will be determined by changing nitrogen (N) availability in these thawing soil profiles. N availability currently limits plant productivity in tundra ecosystems but plant access to N is expected improve as decomposition increases in speed and extends to deeper soil horizons. To evaluate the relationship between permafrost thaw and N availability, we monitored N cycling during 5 years of experimentally induced permafrost thaw at the Carbon in Permafrost Experimental Heating Research (CiPEHR) project. Inorganic N availability increased significantly in response to deeper thaw and greater soil moisture induced by Soil warming. This treatment also prompted a 23{\%} increase in aboveground biomass and a 49{\%} increase in foliar N pools. The sedge Eriophorum vaginatum responded most strongly to warming: this species explained 91{\%} of the change in aboveground biomass during the 5 year period. Air warming had little impact when applied alone, but when applied in combination with Soil warming, growing season soil inorganic N availability was significantly reduced. These results demonstrate that there is a strong positive relationship between the depth of permafrost thaw and N availability in tundra ecosystems but that this relationship can be diminished by interactions between increased thaw, warmer air temperatures, and higher levels of soil moisture. Within 5 years of permafrost thaw, plants actively incorporate newly available N into biomass but C storage in live vascular plant biomass is unlikely to be greater than losses from deep soil C pools.},
author = {Salmon, Verity G and Soucy, Patrick and Mauritz, Marguerite and Celis, Gerardo and Natali, Susan M and Mack, Michelle C and Schuur, Edward A G},
doi = {10.1111/gcb.13204},
issn = {13541013},
journal = {Global Change Biology},
keywords = {Eriophorum vaginatum,carbon balance,decomposition,linear mixed effect model,moist acidic tussock tundra,natural abundance $\delta$15N,plant productivity},
month = {may},
number = {5},
pages = {1927--1941},
title = {{Nitrogen availability increases in a tundra ecosystem during five years of experimental permafrost thaw}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13204 http://doi.wiley.com/10.1111/gcb.13204},
volume = {22},
year = {2016}
}
@article{Salt2015,
author = {Salt, L A and van Heuven, S M A C and Claus, M E and Jones, E M and de Baar, H J W},
doi = {10.5194/bg-12-1387-2015},
journal = {Biogeosciences},
number = {5},
pages = {1387--1401},
title = {{Rapid acidification of mode and intermediate waters in the southwestern Atlantic Ocean}},
url = {https://bg.copernicus.org/articles/12/1387/2015/},
volume = {12},
year = {2015}
}
@article{Sanches2019,
author = {Sanches, L{\'{u}}cia Fernandes and Guenet, Bertrand and Marinho, Claudio Cardoso and Barros, Nathan and {de Assis Esteves}, Francisco},
doi = {10.1038/s41598-018-36519-5},
issn = {2045-2322},
journal = {Scientific Reports},
month = {dec},
number = {1},
pages = {255},
title = {{Global regulation of methane emission from natural lakes}},
url = {http://www.nature.com/articles/s41598-018-36519-5},
volume = {9},
year = {2019}
}
@article{Sanderman2017,
abstract = {Land use and land cover change has resulted in substantial losses of carbon from soils globally, but credible estimates of how much soil carbon has been lost have been difficult to generate. Using a data-driven statistical model and the History Database of the Global Environment v3.2 historic land-use dataset, we estimated that agricultural land uses have resulted in the loss of 133 Pg C from the soil. Importantly, our maps indicate hotspots of soil carbon loss, often associated with major cropping regions and degraded grazing lands, suggesting that there are identifiable regions that should be targets for soil carbon restoration efforts.Human appropriation of land for agriculture has greatly altered the terrestrial carbon balance, creating a large but uncertain carbon debt in soils. Estimating the size and spatial distribution of soil organic carbon (SOC) loss due to land use and land cover change has been difficult but is a critical step in understanding whether SOC sequestration can be an effective climate mitigation strategy. In this study, a machine learning-based model was fitted using a global compilation of SOC data and the History Database of the Global Environment (HYDE) land use data in combination with climatic, landform and lithology covariates. Model results compared favorably with a global compilation of paired plot studies. Projection of this model onto a world without agriculture indicated a global carbon debt due to agriculture of 133 Pg C for the top 2 m of soil, with the rate of loss increasing dramatically in the past 200 years. The HYDE classes “grazing” and “cropland” contributed nearly equally to the loss of SOC. There were higher percent SOC losses on cropland but since more than twice as much land is grazed, slightly higher total losses were found from grazing land. Important spatial patterns of SOC loss were found: Hotspots of SOC loss coincided with some major cropping regions as well as semiarid grazing regions, while other major agricultural zones showed small losses and even net gains in SOC. This analysis has demonstrated that there are identifiable regions which can be targeted for SOC restoration efforts.},
author = {Sanderman, Jonathan and Hengl, Tomislav and Fiske, Gregory J},
doi = {10.1073/pnas.1706103114},
journal = {Proceedings of the National Academy of Sciences},
month = {sep},
number = {36},
pages = {9575--9580},
title = {{Soil carbon debt of 12,000 years of human land use}},
url = {http://www.pnas.org/content/114/36/9575.abstract},
volume = {114},
year = {2017}
}
@article{Sanderson,
abstract = {Cumulative emissions budgets and net-zero emission target dates are often used to frame climate negotiations (Frame et al., 2014; Millar et al., 2016; Van Vuuren et al., 2016; Rogelj et al., 2015b; Matthews et al., 2012). However, their utility for near-term policy decisions is confounded by uncertainties in future negative emissions capacity (Fuss et al., 2014; Smith et al., 2016; Larkin et al., 2018; Anderson and Peters, 2016), in the role of non-CO2 forcers (MacDougall et al., 2015) and in the long-term Earth system response to forcing (Rugenstein et al., 2019; Knutti et al., 2017; Armour, 2017). Such uncertainties may impact the utility of an absolute carbon budget if peak temperatures occur significantly after net-zero emissions are achieved, the likelihood of which is shown here to be conditional on prior assumptions about the long-term dynamics of the Earth system. In the context of these uncertainties, we show that the necessity and scope for negative emissions deployment later in the century can be conditioned on near-term emissions, providing support for a scenario framework which focuses on emissions reductions rather than absolute budgets (Rogelj et al., 2019b).},
author = {Sanderson, Benjamin},
doi = {10.5194/esd-11-563-2020},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {jun},
number = {2},
pages = {563--577},
title = {{The role of prior assumptions in carbon budget calculations}},
url = {https://esd.copernicus.org/articles/11/563/2020/},
volume = {11},
year = {2020}
}
@article{Sarmiento2010,
abstract = {We show here an updated estimate of the net land carbon sink (NLS) as a function of time from 1960 to 2007 calculated from the difference between fossil fuel emissions, the observed atmospheric growth rate, and the ocean uptake obtained by recent ocean model simulations forced with reanalysis wind stress and heat and water fluxes. Except for interannual variability, the net land carbon sink appears to have been relatively constant at a mean value of 0.27 PgC yr1 between 1960 and 1988, at which time it increased abruptly by 0.88 (0.77 to 1.04) PgC yr1 to a new relatively constant mean of 1.15 PgC yr1 between 1989 and 2003/7 (the sign convention is negative out of the atmosphere). This result is detectable at the 99{\%} level using a t-test. The land use source (LU) is relatively constant over this entire time interval. While the LU estimate is highly uncertain, this does imply that most of the change in the net land carbon sink must be due to an abrupt increase in the land sink, LS = NLS LU, in response to some as yet unknown combination of biogeochemical and climate forcing. A regional synthesis and assessment of the land carbon sources and sinks over the post 1988/1989 period reveals broad agreement that the Northern Hemisphere land is a major sink of atmospheric CO2, but there remain major discrepancies with regard to the sign and magnitude of the net flux to and from tropical land.},
author = {Sarmiento, J. L. and Gloor, M. and Gruber, N. and Beaulieu, C. and Jacobson, A. R. and {Mikaloff Fletcher}, S. E. and Pacala, S. and Rodgers, K.},
doi = {10.5194/bg-7-2351-2010},
isbn = {1726-4189},
issn = {1726-4189},
journal = {Biogeosciences},
month = {aug},
number = {8},
pages = {2351--2367},
pmid = {281431800005},
title = {{Trends and regional distributions of land and ocean carbon sinks}},
url = {https://www.biogeosciences.net/7/2351/2010/bg-7-2351-2010.html http://www.biogeosciences.net/7/2351/2010/},
volume = {7},
year = {2010}
}
@article{Sarmiento2002,
author = {Sarmiento, Jorge L. and Gruber, Nicolas},
doi = {10.1063/1.1510279},
issn = {0031-9228},
journal = {Physics Today},
month = {aug},
number = {8},
pages = {30--36},
title = {{Sinks for Anthropogenic Carbon}},
url = {http://physicstoday.scitation.org/doi/10.1063/1.1510279},
volume = {55},
year = {2002}
}
@article{Sasano2015,
abstract = {Abstract The rate of change of dissolved oxygen (O2) concentrations was analyzed over 1987?2011 for the high-frequency repeat section along 165°E in the western North Pacific. Significant trends toward decreasing O2 were detected in the northern subtropical to subtropical-subarctic transition zones over a broad range of isopycnal horizons. On 25.3$\sigma$? between 25°N and 30°N in North Pacific Subtropical Mode Water, the rate of O2 decrease reached ?0.45 ± 0.16 µmol kg?1 yr?1. It is largely attributed to a deepening of isopycnal horizons and to a reduction in oxygen solubility associated with ocean warming. In North Pacific Intermediate Water, the rate of O2 decrease was elevated (?0.44 ± 0.14 µmol kg?1 yr?1 on 26.8$\sigma$?) and was associated with net increases in apparent oxygen utilization in the source waters. On 27.3$\sigma$? in the subtropical Oxygen Minimum Layer (OML) between 32.5°N and 35°N, the rate of O2 decrease was significant (?0.22 ± 0.05 µmol kg?1 yr?1). It was likely due to the increases in westward transport of low-oxygen water. These various drivers controlling changes in O2 along the 165°E section are the same as those acting along 137°E (analyzed previously) and also account for the differences in the rate of O2 decrease between these sections. Additionally, in the tropical OML near 26.8$\sigma$? between 5°N and 10°N, significant trends toward increasing O2 were detected in both sections (+0.36 ± 0.04 µmol kg?1 yr?1 in the 165°E section). These results demonstrate that warming and circulation changes are causing multidecadal changes in dissolved O2 over wide expanses of the western North Pacific.},
annote = {doi: 10.1002/2014GB005065},
author = {Sasano, Daisuke and Takatani, Yusuke and Kosugi, Naohiro and Nakano, Toshiya and Midorikawa, Takashi and Ishii, Masao},
doi = {10.1002/2014GB005065},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {dissolved oxygen,ocean deoxygenation,ocean warming,western North Pacific},
month = {jul},
number = {7},
pages = {935--956},
publisher = {Wiley-Blackwell},
title = {{Multidecadal trends of oxygen and their controlling factors in the western North Pacific}},
url = {https://doi.org/10.1002/2014GB005065 http://doi.wiley.com/10.1002/2014GB005065},
volume = {29},
year = {2015}
}
@article{Sasano2018a,
author = {Sasano, Daisuke and Takatani, Yusuke and Kosugi, Naohiro and Nakano, Toshiya and Midorikawa, Takashi and Ishii, Masao},
doi = {10.1029/2017GB005876},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {bidecadal oscillation,dissolved oxygen,ocean deoxygenation,western North Pacific},
month = {jun},
number = {6},
pages = {909--931},
publisher = {Wiley-Blackwell},
title = {{Decline and Bidecadal Oscillations of Dissolved Oxygen in the Oyashio Region and Their Propagation to the Western North Pacific}},
url = {http://doi.wiley.com/10.1029/2017GB005876},
volume = {32},
year = {2018}
}
@article{Sasmito2019,
author = {Sasmito, Sigit D. and Taillardat, Pierre and Clendenning, Jessica N. and Cameron, Clint and Friess, Daniel A. and Murdiyarso, Daniel and Hutley, Lindsay B.},
doi = {10.1111/gcb.14774},
issn = {1354-1013},
journal = {Global Change Biology},
month = {dec},
number = {12},
pages = {4291--4302},
title = {{Effect of land‐use and land‐cover change on mangrove blue carbon: A systematic review}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.14774},
volume = {25},
year = {2019}
}
@article{Sasse2015,
abstract = {Abstract. Ocean acidification is a predictable consequence of rising atmospheric carbon dioxide (CO2), and is highly likely to impact the entire marine ecosystem – from plankton at the base of the food chain to fish at the top. Factors which are expected to be impacted include reproductive health, organism growth and species composition and distribution. Predicting when critical threshold values will be reached is crucial for projecting the future health of marine ecosystems and for marine resources planning and management. The impacts of ocean acidification will be first felt at the seasonal scale, however our understanding how seasonal variability will influence rates of future ocean acidification remains poorly constrained due to current model and data limitations. To address this issue, we first quantified the seasonal cycle of aragonite saturation state utilizing new data-based estimates of global ocean-surface dissolved inorganic carbon and alkalinity. This seasonality was then combined with earth system model projections under different emissions scenarios (representative concentration pathways; RCPs 2.6, 4.5 and 8.5) to provide new insights into future aragonite undersaturation onset. Under a high emissions scenario (RCP 8.5), our results suggest accounting for seasonality will bring forward the initial onset of month-long undersaturation by 17 ± 10 years compared to annual-mean estimates, with differences extending up to 35 ± 16 years in the North Pacific due to strong regional seasonality. This earlier onset will result in large-scale undersaturation once atmospheric CO2 reaches 496 ppm in the North Pacific and 511 ppm in the Southern Ocean, independent of emission scenario. This work suggests accounting for seasonality is critical to projecting the future impacts of ocean acidification on the marine environment.},
author = {Sasse, T. P. and McNeil, B. I. and Matear, R. J. and Lenton, A.},
doi = {10.5194/bg-12-6017-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {20},
pages = {6017--6031},
title = {{Quantifying the influence of CO2 seasonality on future aragonite undersaturation onset}},
url = {https://www.biogeosciences.net/12/6017/2015/},
volume = {12},
year = {2015}
}
@article{Saunders2018,
abstract = {The Southern Hemisphere westerly winds (SHW) play an important role in regulating the capacity of the Southern Ocean carbon sink. They modulate upwelling of carbon-rich deep water and, with sea ice, determine the ocean surface area available for air–sea gas exchange. Some models indicate that the current strengthening and poleward shift of these winds will weaken the carbon sink. If correct, centennial- to millennial-scale reconstructions of the SHW intensity should be linked with past changes in atmospheric CO2, temperature and sea ice. Here we present a 12,300-year reconstruction of wind strength based on three independent proxies that track inputs of sea-salt aerosols and minerogenic particles accumulating in lake sediments on sub-Antarctic Macquarie Island. Between about 12.1 thousand years ago (ka) and 11.2 ka, and since about 7 ka, the wind intensities were above their long-term mean and corresponded with increasing atmospheric CO2. Conversely, from about 11.2 to 7.2 ka, the wind intensities were below their long-term mean and corresponded with decreasing atmospheric CO2. These observations are consistent with model inferences of enhanced SHW contributing to the long-term outgassing of CO2 from the Southern Ocean.},
author = {Saunders, Krystyna M. and Roberts, Stephen J. and Perren, Bianca and Butz, Christoph and Sime, Louise and Davies, Sarah and {Van Nieuwenhuyze}, Wim and Grosjean, Martin and Hodgson, Dominic A.},
doi = {10.1038/s41561-018-0186-5},
issn = {1752-0894},
journal = {Nature Geoscience},
keywords = {Climate change,Limnology,Palaeoclimate},
month = {sep},
number = {9},
pages = {650--655},
publisher = {Nature Publishing Group},
title = {{Holocene dynamics of the Southern Hemisphere westerly winds and possible links to CO2 outgassing}},
url = {https://doi.org/10.1038/s41561-018-0186-5 http://www.nature.com/articles/s41561-018-0186-5},
volume = {11},
year = {2018}
}
@article{Saunois2020,
author = {Saunois, Marielle and Stavert, Ann R. and Poulter, Ben and Bousquet, Philippe and Canadell, Joseph G. and Jackson, Robert B and Raymond, Peter A. and Dlugokencky, Edward J. and Houweling, Sander and Patra, Prabir K. and Ciais, Philippe and Arora, Vivek K. and Bastviken, David and Bergamaschi, Peter and Blake, Donald R. and Brailsford, Gordon and Bruhwiler, Lori and Carlson, Kimberly M. and Carrol, Mark and Castaldi, Simona and Chandra, Naveen and Crevoisier, Cyril and Crill, Patrick M. and Covey, Kristofer and Curry, Charles L. and Etiope, Giuseppe and Frankenberg, Christian and Gedney, Nicola and Hegglin, Michaela I. and H{\"{o}}glund-Isaksson, Lena and Hugelius, Gustaf and Ishizawa, Misa and Ito, Akihiko and Janssens-Maenhout, Greet and Jensen, Katherine M. and Joos, Fortunat and Kleinen, Thomas and Krummel, Paul B. and Langenfelds, Ray L. and Laruelle, Goulven G. and Liu, Licheng and Machida, Toshinobu and Maksyutov, Shamil and McDonald, Kyle C. and McNorton, Joe and Miller, Paul A. and Melton, Joe R. and Morino, Isamu and M{\"{u}}ller, Jurek and Murguia-Flores, Fabiola and Naik, Vaishali and Niwa, Yosuke and Noce, Sergio and O'Doherty, Simon and Parker, Robert J. and Peng, Changhui and Peng, Shushi and Peters, Glen P. and Prigent, Catherine and Prinn, Ronald and Ramonet, Michel and Regnier, Pierre and Riley, William J. and Rosentreter, Judith A. and Segers, Arjo and Simpson, Isobel J. and Shi, Hao and Smith, Steven J. and Steele, L. Paul and Thornton, Brett F. and Tian, Hanqin and Tohjima, Yasunori and Tubiello, Francesco N. and Tsuruta, Aki and Viovy, Nicolas and Voulgarakis, Apostolos and Weber, Thomas S. and van Weele, Michiel and van der Werf, Guido R. and Weiss, Ray F. and Worthy, Doug and Wunch, Debra and Yin, Yi and Yoshida, Yukio and Zhang, Wenxin and Zhang, Zhen and Zhao, Yuanhong and Zheng, Bo and Zhu, Qing and Zhu, Qiuan and Zhuang, Qianlai},
doi = {10.5194/essd-12-1561-2020},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {jul},
number = {3},
pages = {1561--1623},
title = {{The Global Methane Budget 2000–2017}},
url = {https://essd.copernicus.org/articles/12/1561/2020/},
volume = {12},
year = {2020}
}
@article{Schadel2014,
abstract = {High-latitude ecosystems store approximately 1700 Pg of soil carbon (C), which is twice as much C as is currently contained in the atmosphere. Permafrost thaw and subsequent microbial decomposition of permafrost organic matter could add large amounts of C to the atmosphere, thereby influencing the global C cycle. The rates at which C is being released from the permafrost zone at different soil depths and across different physiographic regions are poorly understood but crucial in understanding future changes in permafrost C storage with climate change. We assessed the inherent decomposability of C from the permafrost zone by assembling a database of long-term ({\textgreater}1 year) aerobic soil incubations from 121 individual samples from 23 high-latitude ecosystems located across the northern circumpolar permafrost zone. Using a three-pool (i.e., fast, slow and passive) decomposition model, we estimated pool sizes for C fractions with different turnover times and their inherent decomposition rates using a reference temperature of 5 {\$}\backslash,{\^{}}{\{}\backslashcirc{\}}{\$}C. Fast cycling C accounted for less than 5{\%} of all C in both organic and mineral soils whereas the pool size of slow cycling C increased with C : N. Turnover time at 5 {\$}\backslash,{\^{}}{\{}\backslashcirc{\}}{\$}C of fast cycling C typically was below 1 year, between 5 and 15 years for slow turning over C, and more than 500 years for passive C. We project that between 20 and 90{\%} of the organic C could potentially be mineralized to CO2 within 50 incubation years at a constant temperature of 5 {\$}\backslash,{\^{}}{\{}\backslashcirc{\}}{\$}C, with vulnerability to loss increasing in soils with higher C : N. These results demonstrate the variation in the vulnerability of C stored in permafrost soils based on inherent differences in organic matter decomposability, and point toward C : N as an index of decomposability that has the potential to be used to scale permafrost C loss across landscapes.},
author = {Sch{\"{a}}del, Christina and Schuur, Edward A G and Bracho, Rosvel and Elberling, Bo and Knoblauch, Christian and Lee, Hanna and Luo, Yiqi and Shaver, Gaius R and Turetsky, Merritt R},
doi = {10.1111/gcb.12417},
isbn = {1365-2486},
issn = {13541013},
journal = {Global Change Biology},
keywords = {Alaska,C decomposition,boreal forest,climate ch},
month = {feb},
number = {2},
pages = {641--652},
title = {{Circumpolar assessment of permafrost C quality and its vulnerability over time using long-term incubation data}},
url = {http://dx.doi.org/10.1111/gcb.12417 http://doi.wiley.com/10.1111/gcb.12417},
volume = {20},
year = {2014}
}
@article{Schadel2016,
abstract = {Increasing temperatures in northern high latitudes are causing permafrost to thaw1, making large amounts of previously frozen organic matter vulnerable to microbial decomposition2. Permafrost thaw also creates a fragmented landscape of drier and wetter soil conditions3,4 that determine the amount and form (carbon dioxide (CO2), or methane (CH4)) of carbon (C) released to the atmosphere. The rate and form of C release control the magnitude of the permafrost C feedback, so their relative contribution with a warming climate remains unclear5,6. We quantified the effect of increasing temperature and changes from aerobic to anaerobic soil conditions using 25 soil incubation studies from the permafrost zone. Here we show, using two separate meta-analyses, that a 10 °C increase in incubation temperature increased C release by a factor of 2.0 (95{\%} confidence interval (CI), 1.8 to 2.2). Under aerobic incubation conditions, soils released 3.4 (95{\%} CI, 2.2 to 5.2) times more C than under anaerobic conditions. Even when accounting for the higher heat trapping capacity of CH4, soils released 2.3 (95{\%} CI, 1.5 to 3.4) times more C under aerobic conditions. These results imply that permafrost ecosystems thawing under aerobic conditions and releasing CO2 will strengthen the permafrost C feedback more than waterlogged systems releasing CO2 and CH4 for a given amount of C.},
author = {Sch{\"{a}}del, Christina and Bader, Martin K.-F. and Schuur, Edward A G and Biasi, Christina and Bracho, Rosvel and {\v{C}}apek, Petr and {De Baets}, Sarah and Di{\'{a}}kov{\'{a}}, Kateřina and Ernakovich, Jessica and Estop-Aragones, Cristian and Graham, David E and Hartley, Iain P and Iversen, Colleen M and Kane, Evan and Knoblauch, Christian and Lupascu, Massimo and Martikainen, Pertti J and Natali, Susan M and Norby, Richard J and O'Donnell, Jonathan A. and Chowdhury, Taniya Roy and {\v{S}}antrů{\v{c}}kov{\'{a}}, Hana and Shaver, Gaius and Sloan, Victoria L. and Treat, Claire C and Turetsky, Merritt R and Waldrop, Mark P and Wickland, Kimberly P},
doi = {10.1038/nclimate3054},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {oct},
number = {10},
pages = {950--953},
publisher = {Nature Publishing Group},
title = {{Potential carbon emissions dominated by carbon dioxide from thawed permafrost soils}},
url = {http://dx.doi.org/10.1038/nclimate3054 http://www.nature.com/articles/nclimate3054},
volume = {6},
year = {2016}
}
@article{Schaefer80,
abstract = {Methane, a powerful and important greenhouse gas, has been accumulating nearly uninterruptedly in the atmosphere for the past 200 years, with the exception of a mysterious plateau between 1999 and 2006. Schaefer et al. measured methane{\{}$\backslash$textquoteright{\}}s carbon isotopic composition in samples collected over the past 35 years in order to constrain the cause of the pause. Lower thermogenic emissions or variations in the hydroxyldriven methane sink caused the plateau. Thermogenic emissions didn{\{}$\backslash$textquoteright{\}}t resume to cause the subsequent rise. Instead, the ongoing rise is most likely due to biogenic sources, most notably agriculture.Science, this issue p. 80Between 1999 and 2006, a plateau interrupted the otherwise continuous increase of atmospheric methane concentration [CH4] since preindustrial times. Causes could be sink variability or a temporary reduction in industrial or climate-sensitive sources. We reconstructed the global history of [CH4] and its stable carbon isotopes from ice cores, archived air, and a global network of monitoring stations. A box-model analysis suggests that diminishing thermogenic emissions, probably from the fossil-fuel industry, and/or variations in the hydroxyl CH4 sink caused the [CH4] plateau. Thermogenic emissions did not resume to cause the renewed [CH4] rise after 2006, which contradicts emission inventories. Post-2006 source increases are predominantly biogenic, outside the Arctic, and arguably more consistent with agriculture than wetlands. If so, mitigating CH4 emissions must be balanced with the need for food production.},
author = {Schaefer, Hinrich and Fletcher, Sara E Mikaloff and Veidt, Cordelia and Lassey, Keith R and Brailsford, Gordon W and Bromley, Tony M and Dlugokencky, Edward J and Michel, Sylvia E and Miller, John B and Levin, Ingeborg and Lowe, Dave C and Martin, Ross J and Vaughn, Bruce H and White, James W C},
doi = {10.1126/science.aad2705},
issn = {0036-8075},
journal = {Science},
month = {apr},
number = {6281},
pages = {80--84},
publisher = {American Association for the Advancement of Science},
title = {{A 21st-century shift from fossil-fuel to biogenic methane emissions indicated by 13CH4}},
url = {http://science.sciencemag.org/content/352/6281/80 http://www.sciencemag.org/cgi/doi/10.1126/science.aad2705},
volume = {352},
year = {2016}
}
@article{Schaefer_2014,
abstract = {Degrading permafrost can alter ecosystems, damage infrastructure, and release enough carbon dioxide (CO2) and methane (CH4) to influence global climate. The permafrost carbon feedback (PCF) is the amplification of surface warming due to CO2 and CH4 emissions from thawing permafrost. An analysis of available estimates PCF strength and timing indicate 120 ± 85 Gt of carbon emissions from thawing permafrost by 2100. This is equivalent to 5.7 ± 4.0{\%} of total anthropogenic emissions for the Intergovernmental Panel on Climate Change (IPCC) representative concentration pathway (RCP) 8.5 scenario and would increase global temperatures by 0.29 ± 0.21 °C or 7.8 ± 5.7{\%}. For RCP4.5, the scenario closest to the 2 °C warming target for the climate change treaty, the range of cumulative emissions in 2100 from thawing permafrost decreases to between 27 and 100 Gt C with temperature increases between 0.05 and 0.15 °C, but the relative fraction of permafrost to total emissions increases to between 3{\%} and 11{\%}. Any substantial warming results in a committed, long-term carbon release from thawing permafrost with 60{\%} of emissions occurring after 2100, indicating that not accounting for permafrost emissions risks overshooting the 2 °C warming target. Climate projections in the IPCC Fifth Assessment Report (AR5), and any emissions targets based on those projections, do not adequately account for emissions from thawing permafrost and the effects of the PCF on global climate. We recommend the IPCC commission a special assessment focusing on the PCF and its impact on global climate to supplement the AR5 in support of treaty negotiation.},
author = {Schaefer, Kevin and Lantuit, Hugues and Romanovsky, Vladimir E and Schuur, Edward A G and Witt, Ronald},
doi = {10.1088/1748-9326/9/8/085003},
journal = {Environmental Research Letters},
number = {8},
pages = {85003},
publisher = {{\{}IOP{\}} Publishing},
title = {{The impact of the permafrost carbon feedback on global climate}},
url = {https://doi.org/10.1088{\%}2F1748-9326{\%}2F9{\%}2F8{\%}2F085003},
volume = {9},
year = {2014}
}
@article{Schaphoff2016432,
abstract = {Russia's boreal forests provide numerous important ecosystem functions and services, but they are being increasingly affected by climate change. This review presents an overview of observed and potential future climate change impacts on those forests with an emphasis on their aggregate carbon balance and processes driving changes therein. We summarize recent findings highlighting that radiation increases, temperature-driven longer growing seasons and increasing atmospheric CO2 concentrations generally enhance vegetation productivity, while heat waves and droughts tend to decrease it. Estimates of major carbon fluxes such as net biome production agree that the Russian forests as a whole currently act as a carbon sink, but these estimates differ in terms of the magnitude of the sink due to different methods and time periods used. Moreover, models project substantial distributional shifts of forest biomes, but they may overestimate the extent to which the boreal forest will shift poleward as past migration rates have been slow. While other impacts of current climate change are already substantial, and projected impacts could be both large-scale and disastrous, the likelihood for a tipping point behavior of Russia's boreal forest is still unquantified. Other substantial research gaps include the large-scale effect of (climate-driven) disturbances such as fires and insect outbreaks, which are expected to increase in the future. We conclude that the impacts of climate change on Russia's boreal forest are often superimposed by other environmental and societal changes in a complex way, and the interaction of these developments could exacerbate both existing and projected future challenges. Hence, development of adaptation and mitigation strategies for Russia's forests is strongly advised. {\textcopyright} 2015 Elsevier B.V.},
annote = {cited By 22},
author = {Schaphoff, S and Reyer, C P O and Schepaschenko, D and Gerten, D and Shvidenko, A},
doi = {10.1016/j.foreco.2015.11.043},
journal = {Forest Ecology and Management},
keywords = {Boreal forests; Carbon balance; Carbon pool; Fore,Carbon dioxide; Fires; Forestry; Permafrost; Produ,Climate change,Hexapoda,Russian Federation,boreal forest; carbon balance; carbon dioxide; cl},
pages = {432--444},
title = {{Tamm Review: Observed and projected climate change impacts on Russia's forests and its carbon balance}},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84948809250{\&}doi=10.1016{\%}2Fj.foreco.2015.11.043{\&}partnerID=40{\&}md5=9b62daffbf86a65c0f96d0e330f7c4f8},
volume = {361},
year = {2016}
}
@article{Scheffer:2012,
abstract = {Although the boreal region is warming twice as fast as the global average, the way in which the vast boreal forests and tundras may respond is poorly understood. Using satellite data, we reveal marked alternative modes in the frequency distributions of boreal tree cover. At the northern end and at the dry continental southern extremes, treeless tundra and steppe, respectively, are the only possible states. However, over a broad intermediate temperature range, these treeless states coexist with boreal forest (∼75{\%} tree cover) and with two more open woodland states (∼20{\%} and ∼45{\%} tree cover). Intermediate tree covers (e.g., ∼10{\%}, ∼30{\%}, and ∼60{\%} tree cover) between these distinct states are relatively rare, suggesting that they may represent unstable states where the system dwells only transiently. Mechanisms for such instabilities remain to be unraveled, but our results have important implications for the anticipated response of these ecosystems to climatic change. The data reveal that boreal forest shows no gradual decline in tree cover toward its limits. Instead, our analysis suggests that it becomes less resilient in the sense that it may more easily shift into a sparse woodland or treeless state. Similarly, the relative scarcity of the intermediate ∼10{\%} tree cover suggests that tundra may shift relatively abruptly to a more abundant tree cover. If our inferences are correct, climate change may invoke massive nonlinear shifts in boreal biomes.},
author = {Scheffer, M and Hirota, M and Holmgren, M and {Van Nes}, E H and Chapin, F. S.},
doi = {10.1073/pnas.1219844110},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {dec},
number = {52},
pages = {21384--21389},
publisher = {Proceedings of the National Academy of Sciences},
title = {{Thresholds for boreal biome transitions}},
url = {http://dx.doi.org/10.1073/pnas.1219844110 http://www.pnas.org/cgi/doi/10.1073/pnas.1219844110},
volume = {109},
year = {2012}
}
@article{Schilt2010a,
abstract = {Reconstructions of past atmospheric concentrations of greenhouse gases provide unique insight into the biogeochemical cycles and the past radiative forcing in the Earth's climate system. We present new measurements of atmospheric nitrous oxide along the ice cores of the North Greenland Ice Core Project and Talos Dome sites. Using records of several other ice cores, we are now able to establish the first complete composite nitrous oxide record reaching back to the beginning of the previous interglacial about 140,000. yr ago. On the basis of such composite ice core records, we further calculate the radiative forcing of the three most important greenhouse gases carbon dioxide, methane and nitrous oxide during more than a full glacial-interglacial cycle. Nitrous oxide varies in line with climate, reaching very low concentrations of about 200 parts per billion by volume during Marine Isotope Stages 4 and 2, and showing substantial responses to millennial time scale climate variations during the last glacial. A large part of these millennial time scale variations can be explained by parallel changes in the sources of methane and nitrous oxide. However, as revealed by high-resolution measurements covering the Dansgaard/Oeschger events 17 to 15, the evolution of these two greenhouse gases may be decoupled on the centennial time scale. Carbon dioxide and methane concentrations do not reach interglacial levels in the course of millennial time scale climate variations during the last glacial. In contrast, nitrous oxide often reaches interglacial concentrations in response to both, glacial terminations and Dansgaard/Oeschger events. This indicates, from a biogeochemical point of view, similar drivers in both temporal cases. While carbon dioxide and methane concentrations are more strongly controlled by climate changes in high latitudes, nitrous oxide emissions changes may mainly stem from the ocean and/or from soils located at low latitudes. Accordingly, we speculate that high latitudes could play the leading role to trigger glacial terminations. {\textcopyright} 2010 Elsevier B.V.},
author = {Schilt, Adrian and Baumgartner, Matthias and Schwander, Jakob and Buiron, Daphn{\'{e}} and Capron, Emilie and Chappellaz, J{\'{e}}r{\^{o}}me and Loulergue, Laetitia and Sch{\"{u}}pbach, Simon and Spahni, Renato and Fischer, Hubertus and Stocker, Thomas F.},
doi = {10.1016/j.epsl.2010.09.027},
isbn = {0012-821X},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {Carbon dioxide,Greenhouse gas,Methane,Nitrous oxide,Paleo,Radiative forcing},
month = {nov},
number = {1-2},
pages = {33--43},
title = {{Atmospheric nitrous oxide during the last 140,000 years}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X10006023},
volume = {300},
year = {2010}
}
@article{Schilt2010,
abstract = {We present records of atmospheric nitrous oxide obtained from the ice cores of the European Project for Ice Coring in Antarctica (EPICA) Dome C and Dronning Maud Land sites shedding light on the concentration of this greenhouse gas on glacial-interglacial and millennial time scales. The extended EPICA Dome C record covers now all interglacials of the last 800,000 years and reveals nitrous oxide variations in concert with climate. Highest mean interglacial nitrous oxide concentrations of 280 parts per billion by volume are observed during the interglacial corresponding to Marine Isotope Stage 11 around 400,000 years before present, at the same time when carbon dioxide and methane reach maximum mean interglacial concentrations. The temperature reconstruction at Dome C indicates colder interglacials between 800,000 and 440,000 years before present compared to the interglacials of the last 440,000 years. In contrast to carbon dioxide and methane, which both respond with lower concentrations at lower temperatures, nitrous oxide shows mean interglacial concentrations of 4-19 parts per billion by volume higher than the preindustrial Holocene value during the interglacials corresponding to Marine Isotope Stage 9-19. At the end of most interglacials, nitrous oxide remains substantially longer on interglacial levels than methane. Nevertheless, nitrous oxide shows millennial-scale variations at the same time as methane throughout the last 800,000 years. We suggest that these millennial-scale variations have been driven by a similar mechanism as the Dansgaard/Oeschger events known from the last glacial. Our data lead to the hypothesis that emissions from the low latitudes drive past variations of the atmospheric nitrous oxide concentration. {\textcopyright} 2009 Elsevier Ltd. All rights reserved.},
author = {Schilt, Adrian and Baumgartner, Matthias and Blunier, Thomas and Schwander, Jakob and Spahni, Renato and Fischer, Hubertus and Stocker, Thomas F.},
doi = {10.1016/j.quascirev.2009.03.011},
isbn = {0277-3791},
issn = {02773791},
journal = {Quaternary Science Reviews},
month = {jan},
number = {1-2},
pages = {182--192},
title = {{Glacial–interglacial and millennial-scale variations in the atmospheric nitrous oxide concentration during the last 800,000 years}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S027737910900119X},
volume = {29},
year = {2010}
}
@article{Schilt2014,
abstract = {Nitrous oxide (N2O) is an important greenhouse gas and ozone-depleting substance that has anthropogenic as well as natural marine and terrestrial sources1. The tropospheric N2O concentrations have varied substantially in the past in concert with changing climate on glacial–interglacial and millennial timescales2, 3, 4, 5, 6, 7, 8. It is not well understood, however, how N2O emissions from marine and terrestrial sources change in response to varying environmental conditions. The distinct isotopic compositions of marine and terrestrial N2O sources can help disentangle the relative changes in marine and terrestrial N2O emissions during past climate variations4, 9, 10. Here we present N2O concentration and isotopic data for the last deglaciation, from 16,000 to 10,000 years before present, retrieved from air bubbles trapped in polar ice at Taylor Glacier, Antarctica. With the help of our data and a box model of the N2O cycle, we find a 30 per cent increase in total N2O emissions from the late glacial to the interglacial, with terrestrial and marine emissions contributing equally to the overall increase and generally evolving in parallel over the last deglaciation, even though there is no a priori connection between the drivers of the two sources. However, we find that terrestrial emissions dominated on centennial timescales, consistent with a state-of-the-art dynamic global vegetation and land surface process model that suggests that during the last deglaciation emission changes were strongly influenced by temperature and precipitation patterns over land surfaces. The results improve our understanding of the drivers of natural N2O emissions and are consistent with the idea that natural N2O emissions will probably increase in response to anthropogenic warming11.},
author = {Schilt, Adrian and Brook, Edward J. and Bauska, Thomas K. and Baggenstos, Daniel and Fischer, Hubertus and Joos, Fortunat and Petrenko, Vasilii V. and Schaefer, Hinrich and Schmitt, Jochen and Severinghaus, Jeffrey P. and Spahni, Renato and Stocker, Thomas F.},
doi = {10.1038/nature13971},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {dec},
number = {7530},
pages = {234--237},
pmid = {25503236},
title = {{Isotopic constraints on marine and terrestrial N2O emissions during the last deglaciation}},
url = {https://www.nature.com/articles/nature13971},
volume = {516},
year = {2014}
}
@article{Schimel2015a,
abstract = {Feedbacks from the terrestrial carbon cycle significantly affect future climate change. The CO2 concentration dependence of global terrestrial carbon storage is one of the largest and most uncertain feedbacks. Theory predicts the CO2 effect should have a tropical maximum, but a large terrestrial sink has been contradicted by analyses of atmospheric CO2 that do not show large tropical uptake. Our results, however, show significant tropical uptake and, combining tropical and extratropical fluxes, suggest that up to 60{\%} of the present-day terrestrial sink is caused by increasing atmospheric CO2. This conclusion is consistent with a validated subset of atmospheric analyses, but uncertainty remains. Improved model diagnostics and new space-based observations can reduce the uncertainty of tropical and temperate zone carbon flux estimates. This analysis supports a significant feedback to future atmospheric CO2 concentrations from carbon uptake in terrestrial ecosystems caused by rising atmospheric CO2 concentrations. This feedback will have substantial tropical contributions, but the magnitude of future carbon uptake by tropical forests also depends on how they respond to climate change and requires their protection from deforestation.},
archivePrefix = {arXiv},
arxivId = {0706.1062v1},
author = {Schimel, David and Stephens, Britton B and Fisher, Joshua B},
doi = {10.1073/pnas.1407302112},
eprint = {0706.1062v1},
isbn = {0027-8424},
issn = {1091-6490},
journal = {Proceedings of the National Academy of Sciences},
number = {2},
pages = {436--441},
pmid = {25548156},
title = {{Effect of increasing CO2 on the terrestrial carbon cycle}},
url = {http://www.pnas.org/content/112/2/436},
volume = {112},
year = {2015}
}
@article{Schlesinger2013,
abstract = {A literature survey of studies reporting nitrous oxide uptake in the soils of natural ecosystems is used to suggest that the median uptake potential is 4 $\mu$g m−2 h−1. The highest values are nearly all associated with soils of wetland and peatland ecosystems. Globally, the consumption of nitrous oxide in soils is not likely to exceed 0.3 TgN yr−1, indicating that the projected sink is not more than 2{\%} of current estimated sources of N2O in the atmosphere.},
author = {Schlesinger, William H.},
doi = {10.1111/gcb.12239},
journal = {Global Change Biology},
month = {oct},
number = {10},
pages = {2929--2931},
publisher = {Wiley/Blackwell (10.1111)},
title = {{An estimate of the global sink for nitrous oxide in soils}},
url = {http://doi.wiley.com/10.1111/gcb.12239},
volume = {19},
year = {2013}
}
@article{Schlunegger2019,
abstract = {The attribution of anthropogenically forced trends in the climate system requires an understanding of when and how such signals emerge from natural variability. We applied time-of-emergence diagnostics to a large ensemble of an Earth system model, which provides both a conceptual framework for interpreting the detectability of anthropogenic impacts in the ocean carbon cycle and observational sampling strategies required to achieve detection. We found emergence timescales that ranged from less than a decade to more than a century, a consequence of the time lag between the chemical and radiative impacts of rising atmospheric CO2 on the ocean. Processes sensitive to carbonate chemical changes emerge rapidly, such as the impacts of acidification on the calcium carbonate pump (10 years for the globally integrated signal and 9–18 years for regionally integrated signals) and the invasion flux of anthropogenic CO2 into the ocean (14 years globally and 13–26 years regionally). Processes sensitive to the ocean's physical state, such as the soft-tissue pump, which depends on nutrients supplied through circulation, emerge decades later (23 years globally and 27–85 years regionally).},
author = {Schlunegger, Sarah and Rodgers, Keith B and Sarmiento, Jorge L and Fr{\"{o}}licher, Thomas L and Dunne, John P and Ishii, Masao and Slater, Richard},
doi = {10.1038/s41558-019-0553-2},
issn = {1758-6798},
journal = {Nature Climate Change},
number = {9},
pages = {719--725},
title = {{Emergence of anthropogenic signals in the ocean carbon cycle}},
url = {https://doi.org/10.1038/s41558-019-0553-2},
volume = {9},
year = {2019}
}
@article{Schmidt2011,
abstract = {Globally, soil organic matter (SOM) contains more than three times as much carbon as either the atmosphere or terrestrial vegetation. Yet it remains largely unknown why some SOM persists for millennia whereas other SOM decomposes readily—and this limits our ability to predict how soils will respond to climate change. Recent analytical and experimental advances have demonstrated that molecular structure alone does not control SOM stability: in fact, environmental and biological controls predominate. Here we propose ways to include this understanding in a new generation of experiments and soil carbon models, thereby improving predictions of the SOM response to global warming.},
annote = {10.1038/nature10386},
author = {Schmidt, Michael W I and Torn, Margaret S and Abiven, Samuel and Dittmar, Thorsten and Guggenberger, Georg and Janssens, Ivan A and Kleber, Markus and K{\"{o}}gel-Knabner, Ingrid and Lehmann, Johannes and Manning, David A C and Nannipieri, Paolo and Rasse, Daniel P and Weiner, Steve and Trumbore, Susan E},
doi = {10.1038/nature10386},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7367},
pages = {49--56},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Persistence of soil organic matter as an ecosystem property}},
url = {http://dx.doi.org/10.1038/nature10386 http://www.nature.com/articles/nature10386},
volume = {478},
year = {2011}
}
@article{Schmidtko2017,
abstract = {Ocean models predict a decline in the dissolved oxygen inventory of the global ocean of one to seven per cent by the year 2100, caused by a combination of a warming-induced decline in oxygen solubility and reduced ventilation of the deep ocean1,2. It is thought that such a decline in the oceanic oxygen content could affect ocean nutrient cycles and the marine habitat, with potentially detrimental consequences for fisheries and coastal economies3,4,5,6. Regional observational data indicate a continuous decrease in oceanic dissolved oxygen concentrations in most regions of the global ocean1,7,8,9,10, with an increase reported in a few limited areas, varying by study1,10. Prior work attempting to resolve variations in dissolved oxygen concentrations at the global scale reported a global oxygen loss of 550 ± 130 teramoles (1012 mol) per decade between 100 and 1,000 metres depth based on a comparison of data from the 1970s and 1990s10. Here we provide a quantitative assessment of the entire ocean oxygen inventory by analysing dissolved oxygen and supporting data for the complete oceanic water column over the past 50 years. We find that the global oceanic oxygen content of 227.4 ± 1.1 petamoles (1015 mol) has decreased by more than two per cent (4.8 ± 2.1 petamoles) since 1960, with large variations in oxygen loss in different ocean basins and at different depths. We suggest that changes in the upper water column are mostly due to a warming-induced decrease in solubility and biological consumption. Changes in the deeper ocean may have their origin in basin-scale multi-decadal variability, oceanic overturning slow-down and a potential increase in biological consumption11,12.},
author = {Schmidtko, Sunke and Stramma, Lothar and Visbeck, Martin},
doi = {10.1038/nature21399},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7641},
pages = {335--339},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Decline in global oceanic oxygen content during the past five decades}},
url = {http://dx.doi.org/10.1038/nature21399 http://www.nature.com/articles/nature21399},
volume = {542},
year = {2017}
}
@article{Schmitt2012,
abstract = {The stable carbon isotope ratio of atmospheric CO2 ($\delta$13Catm) is a key parameter in deciphering past carbon cycle changes. Here we present $\delta$13Catm data for the past 24,000 years derived from three independent records from two Antarctic ice cores. We conclude that a pronounced 0.3 per mil decrease in $\delta$13Catm during the early deglaciation can be best explained by upwelling of old, carbon-enriched waters in the Southern Ocean. Later in the deglaciation, regrowth of the terrestrial biosphere, changes in sea surface temperature, and ocean circulation governed the $\delta$13Catm evolution. During the Last Glacial Maximum, $\delta$13Catm and atmospheric CO2 concentration were essentially constant, which suggests that the carbon cycle was in dynamic equilibrium and that the net transfer of carbon to the deep ocean had occurred before then.},
author = {Schmitt, Jochen and Schneider, Robert and Elsig, Joachim and Leuenberger, D. and Lourantou, Anna and Chappellaz, J{\'{e}}r{\^{o}}me and Kohler, P. and Joos, Fortunat and Stocker, Thomas F. and Leuenberger, Markus and Fischer, Hubertus},
doi = {10.1126/science.1217161},
issn = {0036-8075},
journal = {Science},
month = {may},
number = {6082},
pages = {711--714},
title = {{Carbon Isotope Constraints on the Deglacial CO2 Rise from Ice Cores}},
url = {http://science.sciencemag.org/content/336/6082/711 http://www.sciencemag.org/cgi/doi/10.1126/science.1217161},
volume = {336},
year = {2012}
}
@article{SchneidervonDeimling2015,
abstract = {Abstract. High-latitude soils store vast amounts of perennially frozen and therefore inert organic matter. With rising global temperatures and consequent permafrost degradation, a part of this carbon stock will become available for microbial decay and eventual release to the atmosphere. We have developed a simplified, two-dimensional multi-pool model to estimate the strength and timing of future carbon dioxide (CO2) and methane (CH4) fluxes from newly thawed permafrost carbon (i.e. carbon thawed when temperatures rise above pre-industrial levels). We have especially simulated carbon release from deep deposits in Yedoma regions by describing abrupt thaw under newly formed thermokarst lakes. The computational efficiency of our model allowed us to run large, multi-centennial ensembles under various scenarios of future warming to express uncertainty inherent to simulations of the permafrost carbon feedback. Under moderate warming of the representative concentration pathway (RCP) 2.6 scenario, cumulated CO2 fluxes from newly thawed permafrost carbon amount to 20 to 58 petagrams of carbon (Pg-C) (68{\%} range) by the year 2100 and reach 40 to 98 Pg-C in 2300. The much larger permafrost degradation under strong warming (RCP8.5) results in cumulated CO2 release of 42 to 141 Pg-C and 157 to 313 Pg-C (68{\%} ranges) in the years 2100 and 2300, respectively. Our estimates only consider fluxes from newly thawed permafrost, not from soils already part of the seasonally thawed active layer under pre-industrial climate. Our simulated CH4 fluxes contribute a few percent to total permafrost carbon release yet they can cause up to 40{\%} of total permafrost-affected radiative forcing in the 21st century (upper 68{\%} range). We infer largest CH4 emission rates of about 50 Tg-CH4 per year around the middle of the 21st century when simulated thermokarst lake extent is at its maximum and when abrupt thaw under thermokarst lakes is taken into account. CH4 release from newly thawed carbon in wetland-affected deposits is only discernible in the 22nd and 23rd century because of the absence of abrupt thaw processes. We further show that release from organic matter stored in deep deposits of Yedoma regions crucially affects our simulated circumpolar CH4 fluxes. The additional warming through the release from newly thawed permafrost carbon proved only slightly dependent on the pathway of anthropogenic emission and amounts to about 0.03–0.14 °C (68{\%} ranges) by end of the century. The warming increased further in the 22nd and 23rd century and was most pronounced under the RCP6.0 scenario, adding 0.16 to 0.39 °C (68{\%} range) to simulated global mean surface air temperatures in the year 2300.},
author = {{Schneider von Deimling}, T and Grosse, G and Strauss, J and Schirrmeister, L and Morgenstern, A and Schaphoff, S and Meinshausen, M and Boike, J},
doi = {10.5194/bg-12-3469-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jun},
number = {11},
pages = {3469--3488},
title = {{Observation-based modelling of permafrost carbon fluxes with accounting for deep carbon deposits and thermokarst activity}},
url = {https://www.biogeosciences.net/12/3469/2015/},
volume = {12},
year = {2015}
}
@article{SchneiderVonDeimling2012,
abstract = {Abstract. Thawing of permafrost and the associated release of carbon constitutes a positive feedback in the climate system, elevating the effect of anthropogenic GHG emissions on global-mean temperatures. Multiple factors have hindered the quantification of this feedback, which was not included in climate carbon-cycle models which participated in recent model intercomparisons (such as the Coupled Carbon Cycle Climate Model Intercomparison Project – C4MIP) . There are considerable uncertainties in the rate and extent of permafrost thaw, the hydrological and vegetation response to permafrost thaw, the decomposition timescales of freshly thawed organic material, the proportion of soil carbon that might be emitted as carbon dioxide via aerobic decomposition or as methane via anaerobic decomposition, and in the magnitude of the high latitude amplification of global warming that will drive permafrost degradation. Additionally, there are extensive and poorly characterized regional heterogeneities in soil properties, carbon content, and hydrology. Here, we couple a new permafrost module to a reduced complexity carbon-cycle climate model, which allows us to perform a large ensemble of simulations. The ensemble is designed to span the uncertainties listed above and thereby the results provide an estimate of the potential strength of the feedback from newly thawed permafrost carbon. For the high CO2 concentration scenario (RCP8.5), 33–114 GtC (giga tons of Carbon) are released by 2100 (68 {\%} uncertainty range). This leads to an additional warming of 0.04–0.23 °C. Though projected 21st century permafrost carbon emissions are relatively modest, ongoing permafrost thaw and slow but steady soil carbon decomposition means that, by 2300, about half of the potentially vulnerable permafrost carbon stock in the upper 3 m of soil layer (600–1000 GtC) could be released as CO2, with an extra 1–4 {\%} being released as methane. Our results also suggest that mitigation action in line with the lower scenario RCP3-PD could contain Arctic temperature increase sufficiently that thawing of the permafrost area is limited to 9–23 {\%} and the permafrost-carbon induced temperature increase does not exceed 0.04–0.16 °C by 2300.},
author = {{Schneider von Deimling}, T. and Meinshausen, M. and Levermann, A. and Huber, V. and Frieler, K. and Lawrence, D. M. and Brovkin, V.},
doi = {10.5194/bg-9-649-2012},
issn = {1726-4189},
journal = {Biogeosciences},
month = {feb},
number = {2},
pages = {649--665},
title = {{Estimating the near-surface permafrost-carbon feedback on global warming}},
url = {https://www.biogeosciences.net/9/649/2012/},
volume = {9},
year = {2012}
}
@article{Schuur2015,
abstract = {Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to target poorly understood aspects of permafrost carbon dynamics.},
author = {Schuur, E A G and McGuire, A D and Sch{\"{a}}del, C and Grosse, G and Harden, J W and Hayes, D J and Hugelius, G and Koven, C D and Kuhry, P and Lawrence, D M and Natali, S. M. and Olefeldt, D. and Romanovsky, V. E. and Schaefer, K. and Turetsky, M. R. and Treat, C. C. and Vonk, J. E.},
doi = {10.1038/nature14338},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7546},
pages = {171--179},
publisher = {Nature Publishing Group},
title = {{Climate change and the permafrost carbon feedback}},
url = {https://www.nature.com/articles/nature14338 http://www.nature.com/articles/nature14338},
volume = {520},
year = {2015}
}
@article{Schwalm2012,
abstract = {Fossil fuel emissions aside, temperate North America is a net sink of carbon dioxide at present 1-3. Year-to-year variations in this carbon sink are linked to variations in hydroclimate that affect net ecosystem productivity 3,4. The severity and incidence of climatic extremes, including drought, have increased as a result of climate warming 5-8. Here, we examine the effect of the turn of the century drought in western North America on carbon uptake in the region, using reanalysis data, remote sensing observations and data from global monitoring networks. We show that the area-integrated strength of the western North American carbon sink declined by 30-298 Tg C yr -1 during the 2000-2004 drought. We further document a pronounced drying of the terrestrial biosphere during this period, together with a reduction in river discharge and a loss of cropland productivity. We compare our findings with previous palaeoclimate reconstructions and show that the last drought of this magnitude occurred more than 800 years ago. Based on projected changes in precipitation and drought severity, we estimate that the present mid-latitude carbon sink of 177-623 Tg C yr -1 in western North America could disappear by the end of the century. {\textcopyright} 2012 Macmillan Publishers Limited. All rights reserved.},
author = {Schwalm, Christopher R. and Williams, Christopher A. and Schaefer, Kevin and Baldocchi, Dennis and Black, T. Andrew and Goldstein, Allen H. and Law, Beverly E. and Oechel, Walter C. and {Paw U}, Kyaw Tha and Scott, Russel L.},
doi = {10.1038/ngeo1529},
issn = {17520894},
journal = {Nature Geoscience},
number = {8},
pages = {551--556},
publisher = {Nature Publishing Group},
title = {{Reduction in carbon uptake during turn of the century drought in western North America}},
volume = {5},
year = {2012}
}
@article{Schwarber2018a,
abstract = {Abstract. Simple climate models (SCMs) are numerical representations of the Earth's gas cycles and climate system. SCMs are easy to use and computationally inexpensive, making them an ideal tool in both scientific and decision-making contexts (e.g., complex climate model emulation, parameter estimation experiments, climate metric calculations, and probabilistic analyses). Despite their prolific use, the fundamental responses of SCMs are often not directly characterized. In this study, we use fundamental impulse tests of three chemical species (CO2, CH4, and black carbon – BC) to understand the fundamental gas cycle and climate system responses of several comprehensive (Hector v2.0, MAGICC 5.3, MAGICC 6.0) and idealized (FAIR v1.0, AR5-IR) SCMs. We find that while idealized SCMs are widely used, they fail to capture the magnitude and timescales of global mean climate responses under emissions perturbations, which can produce biased temperature results. Comprehensive SCMs, which have physically based nonlinear forcing and carbon cycle representations, show improved responses compared to idealized SCMs. Even the comprehensive SCMs, however, fail to capture the response timescales to BC emission perturbations seen recently in two general circulation models. Some comprehensive SCMs also generally respond faster than more complex models to a 4×CO2 concentration perturbation, although this was not evident for lower perturbation levels. These results suggest where improvements should be made to SCMs. Further, we demonstrate here a set of fundamental tests that we recommend as a standard evaluation suite for any SCM. Fundamental impulse tests allow users to understand differences in model responses and the impact of model selection on results.},
author = {Schwarber, Adria K. and Smith, Steven J. and Hartin, Corinne A. and Vega-Westhoff, Benjamin Aaron and Sriver, Ryan},
doi = {10.5194/esd-10-729-2019},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {nov},
number = {4},
pages = {729--739},
title = {{Evaluating climate emulation: fundamental impulse testing of simple climate models}},
url = {https://esd.copernicus.org/articles/10/729/2019/},
volume = {10},
year = {2019}
}
@article{Schwietzke2016,
abstract = {Methane has the second-largest global radiative forcing impact of anthropogenic greenhouse gases after carbon dioxide, but our understanding of the global atmospheric methane budget is incomplete. The global fossil fuel industry (production and usage of natural gas, oil and coal) is thought to contribute 15 to 22 per cent of methane emissions1,2,3,4,5,6,7,8,9,10 to the total atmospheric methane budget11. However, questions remain regarding methane emission trends as a result of fossil fuel industrial activity and the contribution to total methane emissions of sources from the fossil fuel industry and from natural geological seepage12,13, which are often co-located. Here we re-evaluate the global methane budget and the contribution of the fossil fuel industry to methane emissions based on long-term global methane and methane carbon isotope records. We compile the largest isotopic methane source signature database so far, including fossil fuel, microbial and biomass-burning methane emission sources. We find that total fossil fuel methane emissions (fossil fuel industry plus natural geological seepage) are not increasing over time, but are 60 to 110 per cent greater than current estimates1,2,3,4,5,6,7,8,9,10 owing to large revisions in isotope source signatures. We show that this is consistent with the observed global latitudinal methane gradient. After accounting for natural geological methane seepage12,13, we find that methane emissions from natural gas, oil and coal production and their usage are 20 to 60 per cent greater than inventories1,2. Our findings imply a greater potential for the fossil fuel industry to mitigate anthropogenic climate forcing, but we also find that methane emissions from natural gas as a fraction of production have declined from approximately 8 per cent to approximately 2 per cent over the past three decades.},
author = {Schwietzke, Stefan and Sherwood, Owen A and Bruhwiler, Lori M P and Miller, John B and Etiope, Giuseppe and Dlugokencky, Edward J and Michel, Sylvia Englund and Arling, Victoria A and Vaughn, Bruce H and White, James W C and Tans, Pieter P},
doi = {10.1038/nature19797},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7623},
pages = {88--91},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Upward revision of global fossil fuel methane emissions based on isotope database}},
url = {http://www.nature.com/doifinder/10.1038/nature19797},
volume = {538},
year = {2016}
}
@article{doi:10.1175/JCLI-D-13-00452.1,
abstract = {Carbon cycle feedbacks are usually categorized into carbon–concentration and carbon–climate feedbacks, which arise owing to increasing atmospheric CO2 concentration and changing physical climate. Both feedbacks are often assumed to operate independently: that is, the total feedback can be expressed as the sum of two independent carbon fluxes that are functions of atmospheric CO2 and climate change, respectively. For phase 5 of the Coupled Model Intercomparison Project (CMIP5), radiatively and biogeochemically coupled simulations have been undertaken to better understand carbon cycle feedback processes. Results show that the sum of total ocean carbon uptake in the radiatively and biogeochemically coupled experiments is consistently larger by 19–58 petagrams of carbon (Pg C) than the uptake found in the fully coupled model runs. This nonlinearity is small compared to the total ocean carbon uptake (533–676 Pg C), but it is of the same order as the carbon–climate feedback. The weakening of ocean circulation and mixing with climate change makes the largest contribution to the nonlinear carbon cycle response since carbon transport to depth is suppressed in the fully relative to the biogeochemically coupled simulations, while the radiatively coupled experiment mainly measures the loss of near-surface carbon owing to warming of the ocean. Sea ice retreat and seawater carbon chemistry contribute less to the simulated nonlinearity. The authors' results indicate that estimates of the ocean carbon–climate feedback derived from “warming only” (radiatively coupled) simulations may underestimate the reduction of ocean carbon uptake in a warm climate high CO2 world.},
author = {Schwinger, J{\"{o}}rg and Tjiputra, Jerry F and Heinze, Christoph and Bopp, Laurent and Christian, James R and Gehlen, Marion and Ilyina, Tatiana and Jones, Chris D and Salas-M{\'{e}}lia, David and Segschneider, Joachim and S{\'{e}}f{\'{e}}rian, Roland and Totterdell, Ian},
doi = {10.1175/JCLI-D-13-00452.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {jun},
number = {11},
pages = {3869--3888},
title = {{Nonlinearity of Ocean Carbon Cycle Feedbacks in CMIP5 Earth System Models}},
url = {https://doi.org/10.1175/JCLI-D-13-00452.1 http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-13-00452.1},
volume = {27},
year = {2014}
}
@article{Seitzinger2000,
abstract = {Context Abstract: Atmospheric concentrations of nitrous oxide, a greenhouse gas, are increasing due to human activities. Our analysis suggests that a third of global anthropogenic N 2 O emission is from aquatic sources (rivers, estuaries, continental shelves) and the terrestrial sources comprise the remainder. Over 80{\%} of aquatic anthropogenic N 2 O emissions are from the Northern Hemisphere mid-latitudes consistent with the geographic distribution of N fertilizer use, human population and atmospheric N deposition. These N inputs to land have increased aquatic as well as terrestrial anthropogenic N 2 O emissions because a substantial portion enters aquatic systems and results in increased N 2 O production. Thus, wise management of N in the terrestrial environment could help reduce/control both aquatic and terrestrial N 2 O emissions. Main Abstract: The global distribution of N 2 O emissions from rivers, estuaries, continental shelves, and oceans are compared to each other, and to terrestrial emissions, using existing gridded inventories. Rivers, estuaries and continental shelves (1.9 Tg N y {\`{A}}1) account for about 35{\%} of total aquatic N 2 O emissions; oceanic emissions comprise the remainder. Oceanic N 2 O emissions are approximately equally distributed between the Northern and Southern Hemispheres ; however, over 90{\%} of emissions from estuaries and rivers are in the Northern Hemisphere. N 2 O emissions from rivers, estuaries, and continental shelves combined equal oceanic emissions in both the 20°±45°N and 45°±66°N lati-tudinal zones. Over 90{\%} of river and estuary emissions are considered anthropogenic (1.2 Tg N y {\`{A}}1); only 25{\%} of continental shelf emissions are considered anthropogenic (0.1 Tg N y {\`{A}}1); oceanic emissions are considered natural. Overall, approximately one third of both aquatic and of terrestrial emissions are anthropogenic. Natural terrestrial emissions are highest in tropical latitudes while natural aquatic emissions are relatively evenly distributed among latitudinal zones. Over half of both the anthropogenic terrestrial and aquatic emissions occur between 20° and 66°N. Anthropogenic N inputs to the terrestrial environment drive anthropogenic N 2 O emissions from both land and aquatic ecosystems, because a substantial portion of the anthropogenic N applied to watersheds enters rivers, estuaries and continental shelves. {\'{O}}},
author = {Seitzinger, Sybil P and Kroeze, Carolien and Styles, Ren{\'{e}}e V},
doi = {10.1016/S1465-9972(00)00015-5},
issn = {14659972},
journal = {Chemosphere - Global Change Science},
month = {jul},
number = {3-4},
pages = {267--279},
title = {{Global distribution of N2O emissions from aquatic systems: natural emissions and anthropogenic effects}},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1465997200000155},
volume = {2},
year = {2000}
}
@article{Semiletov2016,
abstract = {Uptake of atmospheric CO2 contributes to ocean acidification. Measurements of seawater chemistry reveal that the extreme acidity of the East Siberian Arctic Shelf is driven by terrestrial organic matter and freshwater inputs.},
author = {Semiletov, Igor and Pipko, Irina and Gustafsson, {\"{O}}rjan and Anderson, Leif G and Sergienko, Valentin and Pugach, Svetlana and Dudarev, Oleg and Charkin, Alexander and Gukov, Alexander and Br{\"{o}}der, Lisa and Andersson, August and Spivak, Eduard and Shakhova, Natalia},
doi = {10.1038/ngeo2695},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {may},
number = {5},
pages = {361--365},
title = {{Acidification of East Siberian Arctic Shelf waters through addition of freshwater and terrestrial carbon}},
url = {https://doi.org/10.1038/ngeo2695 http://www.nature.com/articles/ngeo2695},
volume = {9},
year = {2016}
}
@article{Serrano2019,
abstract = {Policies aiming to preserve vegetated coastal ecosystems (VCE; tidal marshes, mangroves and seagrasses) to mitigate greenhouse gas emissions require national assessments of blue carbon resources. Here, we present organic carbon (C) storage in VCE across Australian climate regions and estimate potential annual CO 2 emission benefits of VCE conservation and restoration. Australia contributes 5–11{\%} of the C stored in VCE globally (70–185 Tg C in aboveground biomass, and 1,055–1,540 Tg C in the upper 1 m of soils). Potential CO 2 emissions from current VCE losses are estimated at 2.1–3.1 Tg CO 2 -e yr -1 , increasing annual CO 2 emissions from land use change in Australia by 12–21{\%}. This assessment, the most comprehensive for any nation to-date, demonstrates the potential of conservation and restoration of VCE to underpin national policy development for reducing greenhouse gas emissions.},
author = {Serrano, Oscar and Lovelock, Catherine E. and {B. Atwood}, Trisha and Macreadie, Peter I. and Canto, Robert and Phinn, Stuart and Arias-Ortiz, Ariane and Bai, Le and Baldock, Jeff and Bedulli, Camila and Carnell, Paul and Connolly, Rod M. and Donaldson, Paul and Esteban, Alba and {Ewers Lewis}, Carolyn J. and Eyre, Bradley D. and Hayes, Matthew A. and Horwitz, Pierre and Hutley, Lindsay B. and Kavazos, Christopher R. J. and Kelleway, Jeffrey J. and Kendrick, Gary A. and Kilminster, Kieryn and Lafratta, Anna and Lee, Shing and Lavery, Paul S. and Maher, Damien T. and Marb{\`{a}}, N{\'{u}}ria and Masque, Pere and Mateo, Miguel A. and Mount, Richard and Ralph, Peter J. and Roelfsema, Chris and Rozaimi, Mohammad and Ruhon, Radhiyah and Salinas, Cristian and Samper-Villarreal, Jimena and Sanderman, Jonathan and {J. Sanders}, Christian and Santos, Isaac and Sharples, Chris and Steven, Andrew D. L. and Cannard, Toni and Trevathan-Tackett, Stacey M. and Duarte, Carlos M.},
doi = {10.1038/s41467-019-12176-8},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {4313},
title = {{Australian vegetated coastal ecosystems as global hotspots for climate change mitigation}},
url = {http://www.nature.com/articles/s41467-019-12176-8},
volume = {10},
year = {2019}
}
@article{Seshadri2017,
author = {Seshadri, Ashwin K.},
doi = {10.1007/s00382-016-3519-3},
isbn = {0123456789},
issn = {0930-7575},
journal = {Climate Dynamics},
keywords = {Cumulative CO emissions,Energy bala,Global warming,carbon cycle,cumulative co 2 emissions,energy balance models,global warming,path independence},
month = {nov},
number = {9-10},
pages = {3383--3401},
publisher = {Springer Berlin Heidelberg},
title = {{Origin of path independence between cumulative CO2 emissions and global warming}},
url = {http://link.springer.com/10.1007/s00382-016-3519-3},
volume = {49},
year = {2017}
}
@article{Shakhova2017,
author = {Shakhova, Natalia and Semiletov, Igor and Gustafsson, Orjan and Sergienko, Valentin and Lobkovsky, Leopold and Dudarev, Oleg and Tumskoy, Vladimir and Grigoriev, Michael and Mazurov, Alexey and Salyuk, Anatoly and Ananiev, Roman and Koshurnikov, Andrey and Kosmach, Denis and Charkin, Alexander and Dmitrevsky, Nicolay and Karnaukh, Victor and Gunar, Alexey and Meluzov, Alexander and Chernykh, Denis},
doi = {10.1038/ncomms15872},
issn = {2041-1723},
journal = {Nature Communications},
month = {jun},
number = {May},
pages = {15872},
publisher = {Nature Publishing Group},
title = {{Current rates and mechanisms of subsea permafrost degradation in the East Siberian Arctic Shelf}},
url = {http://dx.doi.org/10.1038/ncomms15872 http://www.nature.com/doifinder/10.1038/ncomms15872},
volume = {8},
year = {2017}
}
@article{Shakhova2010,
abstract = {Remobilization to the atmosphere of only a small fraction of the methane held in East Siberian Arctic Shelf (ESAS) sediments could trigger abrupt climate warming, yet it is believed that sub-sea permafrost acts as a lid to keep this shallow methane reservoir in place. Here, we show that more than 5000 at-sea observations of dissolved methane demonstrates that greater than 80{\%} of ESAS bottom waters and greater than 50{\%} of surface waters are supersaturated with methane regarding to the atmosphere. The current atmospheric venting flux, which is composed of a diffusive component and a gradual ebullition component, is on par with previous estimates of methane venting from the entire World Ocean. Leakage of methane through shallow ESAS waters needs to be considered in interactions between the biogeosphere and a warming Arctic climate.},
author = {Shakhova, Natalia and Semiletov, Igor and Salyuk, Anatoly and Yusupov, Vladimir and Kosmach, Denis and Gustafsson, Orjan},
doi = {10.1126/science.1182221},
issn = {0036-8075},
journal = {Science},
month = {mar},
number = {5970},
pages = {1246--1250},
pmid = {20203047},
title = {{Extensive methane venting to the atmosphere from sediments of the East Siberian Arctic shelf}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/20203047 http://www.sciencemag.org/cgi/doi/10.1126/science.1182221},
volume = {327},
year = {2010}
}
@article{Shakhova2014,
author = {Shakhova, Natalia and Semiletov, Igor and Leifer, Ira and Sergienko, Valentin and Salyuk, Anatoly and Kosmach, Denis and Chernykh, Denis and Stubbs, Chris and Nicolsky, Dmitry and Tumskoy, Vladimir and Gustafsson, {\"{O}}rjan},
doi = {10.1038/ngeo2007},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jan},
number = {1},
pages = {64--70},
title = {{Ebullition and storm-induced methane release from the East Siberian Arctic Shelf}},
url = {http://www.nature.com/articles/ngeo2007},
volume = {7},
year = {2014}
}
@article{Shakun2012c,
abstract = {The covariation of carbon dioxide (CO(2)) concentration and temperature in Antarctic ice-core records suggests a close link between CO(2) and climate during the Pleistocene ice ages. The role and relative importance of CO(2) in producing these climate changes remains unclear, however, in part because the ice-core deuterium record reflects local rather than global temperature. Here we construct a record of global surface temperature from 80 proxy records and show that temperature is correlated with and generally lags CO(2) during the last (that is, the most recent) deglaciation. Differences between the respective temperature changes of the Northern Hemisphere and Southern Hemisphere parallel variations in the strength of the Atlantic meridional overturning circulation recorded in marine sediments. These observations, together with transient global climate model simulations, support the conclusion that an antiphased hemispheric temperature response to ocean circulation changes superimposed on globally in-phase warming driven by increasing CO(2) concentrations is an explanation for much of the temperature change at the end of the most recent ice age.},
author = {Shakun, Jeremy D and Clark, Peter U and He, Feng and Marcott, Shaun A and Mix, Alan C and Liu, Zhengyu and Otto-Bliesner, Bette and Schmittner, Andreas and Bard, Edouard},
doi = {10.1038/nature10915},
issn = {0028-0836},
journal = {Nature},
month = {apr},
number = {7392},
pages = {49--54},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation}},
url = {http://dx.doi.org/10.1038/nature10915 http://10.0.4.14/nature10915 https://www.nature.com/articles/nature10915{\#}supplementary-information http://www.nature.com/doifinder/10.1038/nature10915},
volume = {484},
year = {2012}
}
@article{Shao2019,
abstract = {Identifying processes within the Earth System that have modulated atmospheric pCO2 during each glacial cycle of the late Pleistocene stands as one of the grand challenges in climate science. The growing array of surface ocean pH estimates from the boron isotope proxy across the last glacial termination may reveal regions of the ocean that influenced the timing and magnitude of pCO2 rise. Here we present two new boron isotope records from the subtropical-subpolar transition zone of the Southwest Pacific that span the last 20 kyr, as well as new radiocarbon data from the same cores. The new data suggest this region was a source of carbon to the atmosphere rather than a moderate sink as it is today. Significantly higher outgassing is observed between {\~{}}16.5 and 14 kyr BP, associated with increasing $\delta$13C and [CO3]2− at depth, suggesting loss of carbon from the intermediate ocean to the atmosphere. We use these new boron isotope records together with existing records to build a composite pH/pCO2 curve for the surface oceans. The pH disequilibrium/CO2 outgassing was widespread throughout the last deglaciation, likely explained by upwelling of CO2 from the deep/intermediate ocean. During the Holocene, a smaller outgassing peak is observed at a time of relatively stable atmospheric CO2, which may be explained by regrowth of the terrestrial biosphere countering ocean CO2 release. Our stack is likely biased toward upwelling/CO2 source regions. Nevertheless, the composite pCO2 curve provides robust evidence that various parts of the ocean were releasing CO2 to the atmosphere over the last 25 kyr.},
author = {Shao, Jun and Stott, Lowell D. and Gray, William R. and Greenop, Rosanna and Pecher, Ingo and Neil, Helen L. and Coffin, Richard B. and Davy, Bryan and Rae, James W.B.},
doi = {10.1029/2018PA003498},
issn = {25724525},
journal = {Paleoceanography and Paleoclimatology},
number = {10},
pages = {1650--1670},
title = {{Atmosphere–Ocean CO2 Exchange Across the Last Deglaciation From the Boron Isotope Proxy}},
volume = {34},
year = {2019}
}
@article{SHEN2016,
author = {Shen, Q and Hedley, M and {Camps Arbestain}, M and Kirschbaum, M.U.F},
doi = {10.4067/S0718-95162016005000022},
issn = {0718-9516},
journal = {Journal of Soil Science and Plant Nutrition},
number = {2},
pages = {268--286},
publisher = {scielocl},
title = {{Can biochar increase the bioavailability of phosphorus?}},
url = {https://scielo.conicyt.cl/scielo.php?script=sci{\_}arttext{\&}pid=S0718-95162016000200003{\&}nrm=iso http://www.scielo.cl/scielo.php?script=sci{\_}arttext{\&}pid=S0718-95162016005000022{\&}lng=en{\&}nrm=iso{\&}tlng=en},
volume = {16},
year = {2016}
}
@article{Sheng2019,
abstract = {China has large but uncertain coal mine methane (CMM) emissions. Inverse modeling (top-down) analyses of atmospheric methane observations can help improve the emission estimates but require reliable emission patterns as prior information. To serve this urgent need, we developed a high-resolution (0.25° × 0.25°) methane emission inventory for China's coal mining using a recent publicly available database of more than 10000 coal mines in China for 2011. This number of coal mines is 25 and 2.5 times, respectively, more than the number available in the EDGAR v4.2 and EDGAR v4.3.2 gridded global inventories, which have been extensively used in past inverse analyses. Our inventory shows large differences with the EDGAR v4.2 as well as its more recent version, EDGAR v4.3.2. Our results suggest that China's CMM emissions have been decreasing since 2012 on the basis of coal mining activities and assuming time-invariant emission factors but that regional trends differ greatly. Use of our inventory as prior information in future inverse modeling analyses can help better quantify CMM emissions as well as more confidently guide the future mitigation of coal to gas in China.},
author = {Sheng, Jianxiong and Song, Shaojie and Zhang, Yuzhong and Prinn, Ronald G. and Janssens-Maenhout, Greet},
doi = {10.1021/acs.estlett.9b00294},
issn = {23288930},
journal = {Environmental Science and Technology Letters},
number = {8},
pages = {473--478},
title = {{Bottom-Up Estimates of Coal Mine Methane Emissions in China: A Gridded Inventory, Emission Factors, and Trends}},
volume = {6},
year = {2019}
}
@article{acp-13-2653-2013,
author = {Shindell, D T and Pechony, O and Voulgarakis, A and Faluvegi, G and Nazarenko, L and Lamarque, J.-F. and Bowman, K and Milly, G and Kovari, B and Ruedy, R and Schmidt, G A},
doi = {10.5194/acp-13-2653-2013},
journal = {Atmospheric Chemistry and Physics},
number = {5},
pages = {2653--2689},
title = {{Interactive ozone and methane chemistry in GISS-E2 historical and future climate simulations}},
url = {https://www.atmos-chem-phys.net/13/2653/2013/},
volume = {13},
year = {2013}
}
@article{Shinjo2013,
abstract = {Ocean acidification caused by anthropogenically elevated CO2 concentration in the atmosphere can pose a critical threat to calcifying marine organisms and coral reef ecosystems. However, because of temporally and spatially limited instrumental pH records, little is known about the actual long-term trend and natural variability of seawater pH during the past century. We present an annually resolved time series of a pH proxy record for 1940–1999 using boron-isotope composition ($\delta$11B) in a modern massive Porites coral from Guam Island (NW Pacific). When superimposed onto interannual variability, the data show a slightly decreasing trend of {\~{}}0.39‰ (equivalent to {\~{}}0.05–0.08pH units for surface water pH) in the northwestern tropical Pacific since the mid-20th century. This first reported, coral-based reconstruction of long-term open ocean pH is a unique archive for ocean acidification trend in the North Pacific Ocean for the past, which, along with $\delta$11B records from South Pacific corals, can be an important key to ascertaining the extent and rapidity of actual acidification in the Pacific Ocean in the future.},
author = {Shinjo, Ryuichi and Asami, Ryuji and Huang, Kuo-Fang and You, Chen-Feng and Iryu, Yasufumi},
doi = {10.1016/j.margeo.2013.06.002},
issn = {00253227},
journal = {Marine Geology},
keywords = {North Pacific,boron-isotope composition,coral,ocean acidification,pH},
month = {aug},
pages = {58--64},
title = {{Ocean acidification trend in the tropical North Pacific since the mid-20th century reconstructed from a coral archive}},
url = {http://www.sciencedirect.com/science/article/pii/S0025322713001138 https://linkinghub.elsevier.com/retrieve/pii/S0025322713001138},
volume = {342},
year = {2013}
}
@article{Shuttleworth2020,
abstract = {Over the last deglaciation there were two transient intervals of pronounced atmospheric CO2 rise; Heinrich Stadial 1 (17.5-15 kyr) and the Younger Dryas (12.9-11.5 kyr). Leading hypotheses accounting for the increased accumulation of CO2 in the atmosphere at these times invoke deep ocean carbon being released from the Southern Ocean and an associated decline in the global efficiency of the biological carbon pump. Here we present new deglacial surface seawater pH and CO2sw records from the Sub-Antarctic regions of the Atlantic and Pacific oceans using boron isotopes measured on the planktic foraminifera Globigerina bulloides. These new data support the hypothesis that upwelling of carbon-rich water in the Sub-Antarctic occurred during Heinrich Stadial 1, and contributed to the initial increase in atmospheric CO2. The increase in CO2sw is coeval with a decline in biological productivity at both the Sub-Antarctic Atlantic and Pacific sites. However, there is no evidence for a significant outgassing of deep ocean carbon from the Sub-Antarctic during the rest of the deglacial, including the second period of atmospheric CO2 rise coeval with the Younger Dryas. This suggests that the second rapid increase in atmospheric CO2 is driven by processes operating elsewhere in the Southern Ocean, or another region.},
author = {Shuttleworth, R. and Bostock, H.C. and Chalk, T.B. and Calvo, E. and Jaccard, S.L. and Pelejero, C. and Mart{\'{i}}nez-Garc{\'{i}}a, A. and Foster, G.L.},
doi = {10.1016/j.epsl.2020.116649},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {CO2 flux,Heinrich Stadial 1,Southern Ocean,Sub-Antarctic,boron isotopes,deglaciation},
month = {jan},
pages = {116649},
title = {{Early deglacial CO2 release from the Sub-Antarctic Atlantic and Pacific oceans}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X20305938},
volume = {554},
year = {2021}
}
@misc{Siegenthaler2005,
abstract = {A record of atmospheric carbon dioxide (CO2) concentrations measured on the EPICA (European Project for Ice Coring in Antarctica) Dome Concordia ice core extends the Vostok CO2 record back to 650,000 years before the present (yr B.P.). Before 430,000 yr B.P., partial pressure of atmospheric CO2 lies within the range of 260 and 180 parts per million by volume. This range is almost 30{\%} smaller than that of the last four glacial cycles; however, the apparent sensitivity between deuterium and CO2 remains stable throughout the six glacial cycles, suggesting that the relationship between CO2 and Antarctic climate remained rather constant over this interval.},
author = {Siegenthaler, Urs and Stocker, Thomas F and Monnin, Eric and L{\"{u}}thi, Dieter and Schwander, Jakob and Stauffer, Bernhard and Raynaud, Dominique and Barnola, Jean-Marc and Fischer, Hubertus and Masson-Delmotte, Valerie and Jouzel, Jean},
doi = {10.1594/PANGAEA.728136},
publisher = {PANGAEA},
title = {{EPICA Dome C carbon dioxide concentrations from 650 to 391 kyr BP}},
url = {https://doi.pangaea.de/10.1594/PANGAEA.728136},
year = {2005}
}
@article{Sigman2004,
abstract = {The low-latitude ocean is strongly stratified by the warmth of its surface water. As a result, the great volume of the deep ocean has easiest access to the atmosphere through the polar surface ocean. In the modern polar ocean during the winter, the vertical distribution of temperature promotes overturning, with colder water over warmer, while the salinity distribution typically promotes stratification, with fresher water over saltier.However, the sensitivity of seawater density to temperature is reduced as temperature approaches the freezing point, with potential con- sequences for global ocean circulation under cold climates1,2 . Here we present deep-sea records of biogenic opal accumulation and sedimentary nitrogen isotopic composition from the Sub- arctic North Pacific Ocean and the Southern Ocean. These records indicate that vertical stratification increased in both northern and southern high latitudes 2.7 million years ago, when Northern Hemisphere glaciation intensified in association with global cooling during the late Pliocene epoch. We propose that the cooling caused this increased stratification by weakening the role of temperature in polar ocean density structure so as to reduce its opposition to the stratifying effect of the vertical salinity distribution. The shift towards stratification in the polar ocean 2.7 million years ago may have increased the quantity of carbon dioxide trapped in the abyss, amplifying the global cooling. The},
author = {Sigman, Daniel M. and Jaccard, Samuel L. and Haug, Gerald H.},
doi = {10.1038/nature02357},
isbn = {1476-4687 (Electronic)},
issn = {0028-0836},
journal = {Nature},
month = {mar},
number = {6978},
pages = {59--63},
pmid = {14999278},
title = {{Polar ocean stratification in a cold climate}},
url = {https://www.nature.com/articles/nature02357 http://www.nature.com/articles/nature02357},
volume = {428},
year = {2004}
}
@article{Sikes2016,
abstract = {Marine radiocarbon (14C) is widely used to trace ocean circulation and the 14C levels of interior ocean water masses can provide insight into atmosphere-ocean exchange of CO2 the since the last glaciation. Using tephras as stratigraphic tie points with which to estimate past atmospheric $\Delta$14C, we reconstructed a series of deep radiocarbon ages for several time slices from the last glaciation through the deglaciation and Holocene in the Southwestern Pacific. Glacial ventilation ages were much greater in magnitude than modern and had a strong mid-depth $\Delta$14C minimum centered on {\~{}}2500 m. Glacial radiocarbon ages of intermediate depth waters (600-1200 m) were {\~{}}800 to 1600 14C years, about twice modern and persisted through the early deglaciation. Notably, in the glaciation shallower depths were significantly more enriched in 14C than waters between 1600 and 3800 m, which were {\~{}}4000 to 6200 14C years, or about 3-5 times older than modern. Abyssal waters deeper than 4000 m were also more 14C rich than the overlying deep water. With radiocarbon ages of 1800-2300 14C years, this was similar to modern values. In the early deglaciation, $\Delta$14C depleted waters were flushed from shallower depths first and replaced with progressively younger waters such that by {\~{}}18 ka, the deep to intermediate age difference was reduced by half, and by {\~{}}14 ka a modern-type $\Delta$14C profile for deep ocean water masses was in place. Our results 1) confirm a deep 14C depleted water mass during the LGM and early deglaciation, and 2) constrain the extent of this "old" water in the Southern Pacific as between 1600 m and 3800 m. The availability of atmospheric ages from tephras reveals that the presence of older surface reservoir ages in the glaciation caused the estimation of ventilation ages from simple benthic-planktonic offsets to significantly underestimate the depletion of $\Delta$14C in deep waters. This may have had a role in masking the large change in reservoir ages since the glaciation when using benthic-planktonic reservoir age estimates.},
author = {Sikes, Elisabeth L. and Cook, Mea S. and Guilderson, Thomas P.},
doi = {10.1016/j.epsl.2015.12.039},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {CO2,Climate change,Last glaciation,Radiocarbon,Reservoir ages,Southern Ocean},
month = {mar},
pages = {130--138},
publisher = {Elsevier B.V.},
title = {{Reduced deep ocean ventilation in the Southern Pacific Ocean during the last glaciation persisted into the deglaciation}},
url = {http://dx.doi.org/10.1016/j.epsl.2015.12.039 https://linkinghub.elsevier.com/retrieve/pii/S0012821X1500802X},
volume = {438},
year = {2016}
}
@article{Simmons2016,
author = {Simmons, C T and Matthews, H D},
doi = {10.1088/1748-9326/11/3/035001},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {mar},
number = {3},
pages = {035001},
publisher = {IOP Publishing},
title = {{Assessing the implications of human land-use change for the transient climate response to cumulative carbon emissions}},
url = {http://stacks.iop.org/1748-9326/11/i=3/a=035001?key=crossref.66f7869ddb92d6f40c6aff544f9435c5},
volume = {11},
year = {2016}
}
@article{Simpson2012a,
abstract = {After methane, ethane is the most abundant hydrocarbon in the remote atmosphere. It is a precursor to tropospheric ozone and it influences the atmosphere/'s oxidative capacity through its reaction with the hydroxyl radical, ethane/'s primary atmospheric sink. Here we present the longest continuous record of global atmospheric ethane levels. We show that global ethane emission rates decreased from 14.3 to 11.3 teragrams per year, or by 21 per cent, from 1984 to 2010. We attribute this to decreasing fugitive emissions from ethane/'s fossil fuel source—most probably decreased venting and flaring of natural gas in oil fields—rather than a decline in its other major sources, biofuel use and biomass burning. Ethane/'s major emission sources are shared with methane, and recent studies have disagreed on whether reduced fossil fuel or microbial emissions have caused methane/'s atmospheric growth rate to slow. Our findings suggest that reduced fugitive fossil fuel emissions account for at least 10-21 teragrams per year (30-70 per cent) of the decrease in methane/'s global emissions, significantly contributing to methane/'s slowing atmospheric growth rate since the mid-1980s.},
author = {Simpson, Isobel J. and {Sulbaek Andersen}, Mads P. and Meinardi, Simone and Bruhwiler, Lori and Blake, Nicola J. and Helmig, Detlev and Rowland, F. Sherwood and Blake, Donald R.},
doi = {10.1038/nature11342},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7412},
pages = {490--494},
publisher = {Nature Publishing Group},
title = {{Long-term decline of global atmospheric ethane concentrations and implications for methane}},
url = {http://dx.doi.org/10.1038/nature11342 http://www.nature.com/articles/nature11342},
volume = {488},
year = {2012}
}
@article{Singarayer2011,
abstract = {Considerable debate surrounds the source of the apparently anomalousg increase of atmospheric methane concentrations since the mid-Holocene (5,000years ago) compared to previous interglacial periods as recorded in polar ice core records. Proposed mechanisms for the rise in methane concentrations relate either to methane emissions from anthropogenic early rice cultivation or an increase in natural wetland emissions from tropical or boreal sources. Here we show that our climate and wetland simulations of the global methane cycle over the last glacial cycle (the past 130,000years) recreate the ice core record and capture the late Holocene increase in methane concentrations. Our analyses indicate that the late Holocene increase results from natural changes in the Earth's orbital configuration, with enhanced emissions in the Southern Hemisphere tropics linked to precession-induced modification of seasonal precipitation. Critically, our simulations capture the declining trend in methane concentrations at the end of the last interglacial period (115,000-130,000years ago) that was used to diagnose the Holocene methane rise as unique. The difference between the two time periods results from differences in the size and rate of regional insolation changes and the lack of glacial inception in the Holocene. Our findings also suggest that no early agricultural sources are required to account for the increase in methane concentrations in the 5,000years before the industrial era. {\textcopyright} 2011 Macmillan Publishers Limited. All rights reserved.},
author = {Singarayer, Joy S. and Valdes, Paul J. and Friedlingstein, Pierre and Nelson, Sarah and Beerling, David J.},
doi = {10.1038/nature09739},
issn = {00280836},
journal = {Nature},
number = {7332},
pages = {82--86},
pmid = {21293375},
title = {{Late Holocene methane rise caused by orbitally controlled increase in tropical sources}},
volume = {470},
year = {2011}
}
@article{Sitch2015,
abstract = {Abstract. The land and ocean absorb on average just over half of the anthropogenic emissions of carbon dioxide (CO2) every year. These CO2 "sinks" are modulated by climate change and variability. Here we use a suite of nine dynamic global vegetation models (DGVMs) and four ocean biogeochemical general circulation models (OBGCMs) to estimate trends driven by global and regional climate and atmospheric CO2 in land and oceanic CO2 exchanges with the atmosphere over the period 1990–2009, to attribute these trends to underlying processes in the models, and to quantify the uncertainty and level of inter-model agreement. The models were forced with reconstructed climate fields and observed global atmospheric CO2; land use and land cover changes are not included for the DGVMs. Over the period 1990–2009, the DGVMs simulate a mean global land carbon sink of −2.4 ± 0.7 Pg C yr−1 with a small significant trend of −0.06 ± 0.03 Pg C yr−2 (increasing sink). Over the more limited period 1990–2004, the ocean models simulate a mean ocean sink of −2.2 ± 0.2 Pg C yr−1 with a trend in the net C uptake that is indistinguishable from zero (−0.01 ± 0.02 Pg C yr−2). The two ocean models that extended the simulations until 2009 suggest a slightly stronger, but still small, trend of −0.02 ± 0.01 Pg C yr−2. Trends from land and ocean models compare favourably to the land greenness trends from remote sensing, atmospheric inversion results, and the residual land sink required to close the global carbon budget. Trends in the land sink are driven by increasing net primary production (NPP), whose statistically significant trend of 0.22 ± 0.08 Pg C yr−2 exceeds a significant trend in heterotrophic respiration of 0.16 ± 0.05 Pg C yr−2 – primarily as a consequence of widespread CO2 fertilisation of plant production. Most of the land-based trend in simulated net carbon uptake originates from natural ecosystems in the tropics (−0.04 ± 0.01 Pg C yr−2), with almost no trend over the northern land region, where recent warming and reduced rainfall offsets the positive impact of elevated atmospheric CO2 and changes in growing season length on carbon storage. The small uptake trend in the ocean models emerges because climate variability and change, and in particular increasing sea surface temperatures, tend to counter$\backslash$$\backslash$-act the trend in ocean uptake driven by the increase in atmospheric CO2. Large uncertainty remains in the magnitude and sign of modelled carbon trends in several regions, as well as regarding the influence of land use and land cover changes on regional trends.},
author = {Sitch, S. and Friedlingstein, P. and Gruber, N. and Jones, S. D. and Murray-Tortarolo, G. and Ahlstr{\"{o}}m, A. and Doney, S. C. and Graven, H. and Heinze, C. and Huntingford, C. and Levis, S. and Levy, P. E. and Lomas, M. and Poulter, B. and Viovy, N. and Zaehle, S. and Zeng, N. and Arneth, A. and Bonan, G. and Bopp, L. and Canadell, J. G. and Chevallier, F. and Ciais, P. and Ellis, R. and Gloor, M. and Peylin, P. and Piao, S. L. and {Le Qu{\'{e}}r{\'{e}}}, C. and Smith, B. and Zhu, Z. and Myneni, R.},
doi = {10.5194/bg-12-653-2015},
isbn = {1726-4189},
issn = {1726-4189},
journal = {Biogeosciences},
month = {feb},
number = {3},
pages = {653--679},
title = {{Recent trends and drivers of regional sources and sinks of carbon dioxide}},
url = {https://www.biogeosciences.net/12/653/2015/bg-12-653-2015.html https://www.biogeosciences.net/12/653/2015/},
volume = {12},
year = {2015}
}
@article{Sjogersten2020,
author = {Sj{\"{o}}gersten, Sofie and Siegenthaler, Andy and Lopez, Omar R. and Aplin, Paul and Turner, Benjamin and Gauci, Vincent},
doi = {10.1111/nph.16178},
issn = {0028-646X},
journal = {New Phytologist},
month = {jan},
number = {2},
pages = {769--781},
title = {{Methane emissions from tree stems in neotropical peatlands}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.16178},
volume = {225},
year = {2020}
}
@article{Skinner2015,
abstract = {It has been proposed that the ventilation of the deep Pacific carbon pool was not significantly reduced during the last glacial period, posing a problem for canonical theories of glacial-interglacial CO2change. However, using radiocarbon dates of marine tephra deposited off New Zealand, we show that deep- ({\textgreater}2000m) and shallow sub-surface ocean-atmosphere14C age offsets (i.e. 'reservoir-' or 'ventilation' ages) in the southwest Pacific increased by {\~{}}1089 and 337 yrs respectively, reaching {\~{}}2689 and {\~{}}1037 yrs during the late glacial. A comparison with other radiocarbon data from the southern high-latitudes suggests that broadly similar changes were experienced right across the Southern Ocean. If, like today, the Southern Ocean was the main source of water to the glacial ocean interior, these observations would imply a significant change in the global radiocarbon inventory during the last glacial period, possibly equivalent to an increase in the average radiocarbon age {\textgreater}2km of {\~{}}700yrs. Simple mass balance arguments and numerical model sensitivity tests suggest that such a change in the ocean's mean radiocarbon age would have had a major impact on the marine carbon inventory and atmospheric CO2, possibly accounting for nearly half of the glacial-interglacial CO2change. If confirmed, these findings would underline the special role of high latitude shallow sub-surface mixing and air-sea gas exchange in regulating atmospheric CO2during the late Pleistocene.},
author = {Skinner, L.C. and McCave, I.N. and Carter, L. and Fallon, S. and Scrivner, A.E. and Primeau, F.},
doi = {10.1016/j.epsl.2014.11.024},
isbn = {0012-821X},
issn = {0012821X},
journal = {Earth and Planetary Science Letters},
keywords = {Carbon cycling,Ocean ventilation,Palaeoceanography,Radiocarbon},
month = {feb},
pages = {45--52},
title = {{Reduced ventilation and enhanced magnitude of the deep Pacific carbon pool during the last glacial period}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012821X1400716X},
volume = {411},
year = {2015}
}
@article{Skinner2017,
abstract = {While the ocean's large-scale overturning circulation is thought to have been significantly different under the climatic conditions of the Last Glacial Maximum (LGM), the exact nature of the glacial circulation and its implications for global carbon cycling continue to be debated. Here we use a global array of ocean–atmosphere radiocarbon disequilibrium estimates to demonstrate a B689±53 14C-yr increase in the average residence time of carbon in the deep ocean at the LGM. A predominantly southern-sourced abyssal overturning limb that was more isolated from its shallower northern counterparts is interpreted to have extended from the Southern Ocean, producing a widespread radiocarbon age maximum at mid-depths and depriving the deep ocean of a fast escape route for accumulating respired carbon. While the exact magnitude of the resulting carbon cycle impacts remains to be confirmed, the radio- carbon data suggest an increase in the efficiency of the biological carbon pump that could have accounted for as much as half of the glacial–interglacial CO2 change.},
author = {Skinner, L. C. and Primeau, F. and Freeman, E. and de la Fuente, M. and Goodwin, P. A. and Gottschalk, J. and Huang, E. and McCave, I. N. and Noble, T. L. and Scrivner, A. E.},
doi = {10.1038/ncomms16010},
issn = {2041-1723},
journal = {Nature Communications},
month = {jul},
pages = {16010},
title = {{Radiocarbon constraints on the glacial ocean circulation and its impact on atmospheric CO2}},
url = {http://www.nature.com/doifinder/10.1038/ncomms16010},
volume = {8},
year = {2017}
}
@article{Skinner2010,
abstract = {Past glacial-interglacial increases in the concentration of atmospheric carbon dioxide (CO2) are thought to arise from the rapid release of CO2 sequestered in the deep sea, primarily via the Southern Ocean. Here, we present radiocarbon evidence from the Atlantic sector of the Southern Ocean that strongly supports this hypothesis. We show that during the last glacial period, deep water circulating around Antarctica was more than two times older than today relative to the atmosphere. During deglaciation, the dissipation of this old and presumably CO2-enriched deep water played an important role in the pulsed rise of atmospheric CO2 through its variable influence on the upwelling branch of the Antarctic overturning circulation.},
author = {Skinner, L C and Fallon, S and Waelbroeck, C and Michel, E and Barker, S},
doi = {10.1126/science.1183627},
issn = {0036-8075},
journal = {Science},
month = {may},
number = {5982},
pages = {1147--1151},
pmid = {20508128},
publisher = {American Association for the Advancement of Science},
title = {{Ventilation of the Deep Southern Ocean and Deglacial CO2 Rise}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/20508128 http://www.sciencemag.org/cgi/doi/10.1126/science.1183627 https://www.sciencemag.org/lookup/doi/10.1126/science.1183627},
volume = {328},
year = {2010}
}
@article{Sluijs2006,
abstract = {The Palaeocene/Eocene thermal maximum, approx55 million years ago, was a brief period of widespread, extreme climatic warming1, 2, 3, that was associated with massive atmospheric greenhouse gas input4. Although aspects of the resulting environmental changes are well documented at low latitudes, no data were available to quantify simultaneous changes in the Arctic region. Here we identify the Palaeocene/Eocene thermal maximum in a marine sedimentary sequence obtained during the Arctic Coring Expedition5. We show that sea surface temperatures near the North Pole increased from approx18 °C to over 23 °C during this event. Such warm values imply the absence of ice and thus exclude the influence of ice-albedo feedbacks on this Arctic warming. At the same time, sea level rose while anoxic and euxinic conditions developed in the ocean's bottom waters and photic zone, respectively. Increasing temperature and sea level match expectations based on palaeoclimate model simulations6, but the absolute polar temperatures that we derive before, during and after the event are more than 10 °C warmer than those model-predicted. This suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms—perhaps polar stratospheric clouds7 or hurricane-induced ocean mixing8—to amplify early Palaeogene polar temperatures.},
archivePrefix = {arXiv},
arxivId = {Figures, S., 2010. Supplementary information. Nature, 1(c), pp.1–7. Available at: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3006164{\&}tool=pmcentrez{\&}rendertype=abstract.},
author = {Sluijs, Appy and Schouten, Stefan and Pagani, Mark and Woltering, Martijn and Brinkhuis, Henk and Damst{\'{e}}, Jaap S. Sinninghe and Dickens, Gerald R. and Huber, Matthew and Reichart, Gert-Jan and Stein, Ruediger and Matthiessen, Jens and Lourens, Lucas J. and Pedentchouk, Nikolai and Backman, Jan and Moran, Kathryn},
doi = {10.1038/nature04668},
eprint = {/www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3006164{\&}tool=pmcentrez{\&}rendertype=abstract.},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {jun},
number = {7093},
pages = {610--613},
pmid = {16752441},
primaryClass = {Figures, S., 2010. Supplementary information. Nature, 1(c), pp.1–7. Available at: http:},
title = {{Subtropical Arctic Ocean temperatures during the Palaeocene/Eocene thermal maximum}},
url = {http://www.nature.com/articles/nature04668},
volume = {441},
year = {2006}
}
@article{Smale2019,
abstract = {The global ocean has warmed substantially over the past century, with far-reaching implications for marine ecosystems1. Concurrent with long-term persistent warming, discrete periods of extreme regional ocean warming (marine heatwaves, MHWs) have increased in frequency2. Here we quantify trends and attributes of MHWs across all ocean basins and examine their biological impacts from species to ecosystems. Multiple regions in the Pacific, Atlantic and Indian Oceans are particularly vulnerable to MHW intensification, due to the co-existence of high levels of biodiversity, a prevalence of species found at their warm range edges or concurrent non-climatic human impacts. The physical attributes of prominent MHWs varied considerably, but all had deleterious impacts across a range of biological processes and taxa, including critical foundation species (corals, seagrasses and kelps). MHWs, which will probably intensify with anthropogenic climate change3, are rapidly emerging as forceful agents of disturbance with the capacity to restructure entire ecosystems and disrupt the provision of ecological goods and services in coming decades.},
author = {Smale, Dan A and Wernberg, Thomas and Oliver, Eric C J and Thomsen, Mads and Harvey, Ben P and Straub, Sandra C and Burrows, Michael T and Alexander, Lisa V and Benthuysen, Jessica A and Donat, Markus G and Feng, Ming and Hobday, Alistair J and Holbrook, Neil J and Perkins-Kirkpatrick, Sarah E and Scannell, Hillary A and {Sen Gupta}, Alex and Payne, Ben L and Moore, Pippa J},
doi = {10.1038/s41558-019-0412-1},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {apr},
number = {4},
pages = {306--312},
title = {{Marine heatwaves threaten global biodiversity and the provision of ecosystem services}},
url = {https://doi.org/10.1038/s41558-019-0412-1 http://www.nature.com/articles/s41558-019-0412-1},
volume = {9},
year = {2019}
}
@article{Smith2015,
author = {Smith, Nicholas G and Malyshev, Sergey L and Shevliakova, Elena and Kattge, Jens and Dukes, Jeffrey S},
doi = {10.1038/nclimate2878},
journal = {Nature Climate Change},
month = {dec},
pages = {407},
publisher = {Nature Publishing Group},
title = {{Foliar temperature acclimation reduces simulated carbon sensitivity to climate}},
url = {https://doi.org/10.1038/nclimate2878 http://10.0.4.14/nclimate2878 https://www.nature.com/articles/nclimate2878{\#}supplementary-information},
volume = {6},
year = {2015}
}
@article{Smith2016a,
abstract = {To have a {\textgreater}50{\%} chance of limiting warming below 2 [deg]C, most recent scenarios from integrated assessment models (IAMs) require large-scale deployment of negative emissions technologies (NETs). These are technologies that result in the net removal of greenhouse gases from the atmosphere. We quantify potential global impacts of the different NETs on various factors (such as land, greenhouse gas emissions, water, albedo, nutrients and energy) to determine the biophysical limits to, and economic costs of, their widespread application. Resource implications vary between technologies and need to be satisfactorily addressed if NETs are to have a significant role in achieving climate goals.},
author = {Smith, Pete and Davis, Steven J and Creutzig, Felix and Fuss, Sabine and Minx, Jan and Gabrielle, Benoit and Kato, Etsushi and Jackson, Robert B and Cowie, Annette and Kriegler, Elmar and van Vuuren, Detlef P and Rogelj, Joeri and Ciais, Philippe and Milne, Jennifer and Canadell, Josep G and McCollum, David and Peters, Glen and Andrew, Robbie and Krey, Volker and Shrestha, Gyami and Friedlingstein, Pierre and Gasser, Thomas and Gr{\"{u}}bler, Arnulf and Heidug, Wolfgang K and Jonas, Matthias and Jones, Chris D and Kraxner, Florian and Littleton, Emma and Lowe, Jason and Moreira, Jos{\'{e}} Roberto and Nakicenovic, Nebojsa and Obersteiner, Michael and Patwardhan, Anand and Rogner, Mathis and Rubin, Ed and Sharifi, Ayyoob and Torvanger, Asbj{\o}rn and Yamagata, Yoshiki and Edmonds, Jae and Yongsung, Cho},
doi = {10.1038/nclimate2870},
isbn = {1758-678X},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jan},
number = {1},
pages = {42--50},
publisher = {Nature Publishing Group},
title = {{Biophysical and economic limits to negative CO2 emissions}},
url = {http://dx.doi.org/10.1038/nclimate2870 http://www.nature.com/articles/nclimate2870},
volume = {6},
year = {2016}
}
@article{Smith2018c,
abstract = {Simple climate models can be valuable if they are able to replicate aspects of complex fully coupled earth system models. Larger ensembles can be produced, enabling a probabilistic view of future climate change. A simple emissions-based climate model, FAIR, is presented, which calculates atmospheric concentrations of greenhouse gases and effective radiative forcing (ERF) from greenhouse gases, aerosols, ozone and other agents. Model runs are constrained to observed temperature change from 1880 to 2016 and produce a range of future projections under the Representative Concentration Pathway (RCP) scenarios. The constrained estimates of equilibrium climate sensitivity (ECS), transient climate response (TCR) and transient climate response to cumulative CO2 emissions (TCRE) are 2.86 (2.01 to 4.22)K, 1.53 (1.05 to 2.41)K and 1.40 (0.96 to 2.23)K (1000GtC)−1 (median and 5–95{\%} credible intervals). These are in good agreement with the likely Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) range, noting that AR5 estimates were derived from a combination of climate models, observations and expert judgement. The ranges of future projections of temperature and ranges of estimates of ECS, TCR and TCRE are somewhat sensitive to the prior distributions of ECS∕TCR parameters but less sensitive to the ERF from a doubling of CO2 or the observational temperature dataset used to constrain the ensemble. Taking these sensitivities into account, there is no evidence to suggest that the median and credible range of observationally constrained TCR or ECS differ from climate model-derived estimates. The range of temperature projections under RCP8.5 for 2081–2100 in the constrained FAIR model ensemble is lower than the emissions-based estimate reported in AR5 by half a degree, owing to differences in forcing assumptions and ECS∕TCR distributions. ]]{\textgreater}},
author = {Smith, Christopher J. and Forster, Piers M. and Allen, Myles and Leach, Nicholas and Millar, Richard J. and Passerello, Giovanni A. and Regayre, Leighton A.},
doi = {10.5194/gmd-11-2273-2018},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {jun},
number = {6},
pages = {2273--2297},
publisher = {Copernicus GmbH},
title = {{FAIR v1.3: a simple emissions-based impulse response and carbon cycle model}},
url = {https://www.geosci-model-dev.net/11/2273/2018/ https://gmd.copernicus.org/articles/11/2273/2018/},
volume = {11},
year = {2018}
}
@article{Smith14202,
abstract = {Emissions reductions focused on anthropogenic climate-forcing agents with relatively short atmospheric lifetimes, such as methane (CH4) and black carbon, have been suggested as a strategy to reduce the rate of climate change over the next several decades. We find that reductions of methane and black carbon would likely have only a modest impact on near-term global climate warming. Even with maximally feasible reductions phased in from 2015 to 2035, global mean temperatures in 2050 would be reduced by 0.16 {\{}$\backslash$textdegree{\}}C, with a range of 0.04{\{}$\backslash$textendash{\}}0.35 {\{}$\backslash$textdegree{\}}C because of uncertainties in carbonaceous aerosol emissions and aerosol forcing per unit of emissions. The high end of this range is only possible if total historical aerosol forcing is relatively small. More realistic emission reductions would likely provide an even smaller climate benefit. We find that the climate benefit from reductions in short-lived forcing agents are smaller than previously estimated. These near-term climate benefits of targeted reductions in short-lived forcers are not substantially different in magnitude from the benefits from a comprehensive climate policy.},
author = {Smith, Steven J and Mizrahi, Andrew},
doi = {10.1073/pnas.1308470110},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {aug},
number = {35},
pages = {14202--14206},
publisher = {National Academy of Sciences},
title = {{Near-term climate mitigation by short-lived forcers}},
url = {https://www.pnas.org/content/110/35/14202 http://www.pnas.org/cgi/doi/10.1073/pnas.1308470110},
volume = {110},
year = {2013}
}
@article{Smith2018b,
abstract = {We applied a recently developed tool to examine the reduction in climate risk to biodiversity in moving from a 2°C to a 1.5°C target. We then reviewed the recent literature examining the impact of (a) land-based mitigation options and (b) land-based greenhouse gas removal options on biodiversity. We show that holding warming to 1.5°C versus 2°C can significantly reduce the number of species facing a potential loss of 50{\%} of their climatic range. Further, there would be an increase of 5.5–14{\%} of the globe that could potentially act as climatic refugia for plants and animals, an area equivalent to the current global protected area network. Efforts to meet the 1.5°C target through mitigation could largely be consistent with biodiversity protection/enhancement. For impacts of land-based greenhouse gas removal technologies on biodiversity, some (e.g. soil carbon sequestration) could be neutral or positive, others (e.g. bioenergy with carbon capture and storage) are likely to lead to conflicts, while still others (e.g. afforestation/reforestation) are context-specific, when applied at scales necessary for meaningful greenhouse gas removal. Additional effort to meet the 1.5°C target presents some risks, particularly if inappropriately managed, but it also presents opportunities.},
annote = {doi: 10.1098/rsta.2016.0456},
author = {Smith, Pete and Price, Jeff and Molotoks, Amy and Warren, Rachel and Malhi, Yadvinder},
doi = {10.1098/rsta.2016.0456},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {may},
number = {2119},
pages = {20160456},
publisher = {Royal Society},
title = {{Impacts on terrestrial biodiversity of moving from a 2°C to a 1.5°C target}},
url = {https://doi.org/10.1098/rsta.2016.0456 http://rsta.royalsocietypublishing.org/lookup/doi/10.1098/rsta.2016.0456 https://royalsocietypublishing.org/doi/10.1098/rsta.2016.0456},
volume = {376},
year = {2018}
}
@article{Smith2013d,
author = {Smith, Nicholas G and Dukes, Jeffrey S},
doi = {10.1111/j.1365-2486.2012.02797.x},
issn = {13541013},
journal = {Global Change Biology},
month = {jan},
number = {1},
pages = {45--63},
title = {{Plant respiration and photosynthesis in global-scale models: incorporating acclimation to temperature and CO2}},
url = {http://doi.wiley.com/10.1111/j.1365-2486.2012.02797.x},
volume = {19},
year = {2013}
}
@article{Smith2016e,
author = {Smith, Pete},
doi = {10.1111/gcb.13178},
issn = {13541013},
journal = {Global Change Biology},
language = {en},
month = {mar},
number = {3},
pages = {1315--1324},
title = {{Soil carbon sequestration and biochar as negative emission technologies}},
url = {http://doi.wiley.com/10.1111/gcb.13178},
volume = {22},
year = {2016}
}
@article{Smith2020,
author = {Smith, Marielle N. and Taylor, Tyeen C. and van Haren, Joost and Rosolem, Rafael and Restrepo-Coupe, Natalia and Adams, John and Wu, Jin and de Oliveira, Raimundo C. and da Silva, Rodrigo and de Araujo, Alessandro C. and de Camargo, Plinio B. and Huxman, Travis E. and Saleska, Scott R.},
doi = {10.1038/s41477-020-00780-2},
issn = {2055-0278},
journal = {Nature Plants},
month = {oct},
number = {10},
pages = {1225--1230},
title = {{Empirical evidence for resilience of tropical forest photosynthesis in a warmer world}},
url = {https://www.nature.com/articles/s41477-020-00780-2},
volume = {6},
year = {2020}
}
@article{Smith2017,
abstract = {Abstract While temperature responses of photosynthesis and plant respiration are known to acclimate over time in many species, few studies have been designed to directly compare process-level differences in acclimation capacity among plant types. We assessed short-term (7 day) temperature acclimation of the maximum rate of Rubisco carboxylation (Vcmax), the maximum rate of electron transport (Jmax), the maximum rate of phosphoenolpyruvate carboxylase carboxylation (Vpmax), and foliar dark respiration (Rd) in 22 plant species that varied in lifespan (annual and perennial), photosynthetic pathway (C3 and C4), and climate of origin (tropical and nontropical) grown under fertilized, well-watered conditions. In general, acclimation to warmer temperatures increased the rate of each process. The relative increase in different photosynthetic processes varied by plant type, with C3 species tending to preferentially accelerate CO2-limited photosynthetic processes and respiration and C4 species tending to preferentially accelerate light-limited photosynthetic processes under warmer conditions. Rd acclimation to warmer temperatures caused a reduction in temperature sensitivity that resulted in slower rates at high leaf temperatures. Rd acclimation was similar across plant types. These results suggest that temperature acclimation of the biochemical processes that underlie plant carbon exchange is common across different plant types, but that acclimation to warmer temperatures tends to have a relatively greater positive effect on the processes most limiting to carbon assimilation, which differ by plant type. The acclimation responses observed here suggest that warmer conditions should lead to increased rates of carbon assimilation when water and nutrients are not limiting.},
annote = {doi: 10.1111/gcb.13735},
author = {Smith, Nicholas G and Dukes, Jeffrey S},
doi = {10.1111/gcb.13735},
issn = {1354-1013},
journal = {Global Change Biology},
keywords = {Jmax,Vcmax,climate change,photosynthesis,plant physiology,respiration,warming},
month = {nov},
number = {11},
pages = {4840--4853},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Short-term acclimation to warmer temperatures accelerates leaf carbon exchange processes across plant types}},
url = {https://doi.org/10.1111/gcb.13735},
volume = {23},
year = {2017}
}
@article{Smith2019,
abstract = {Land-management options for greenhouse gas removal (GGR) include afforestation or reforestation (AR), wetland restoration, soil carbon sequestration (SCS), biochar, terrestrial enhanced weathering (TEW), and bioenergy with carbon capture and storage (BECCS). We assess the opportunities and risks associated with these options through the lens of their potential impacts on ecosystem services (Nature's Contributions to People; NCPs) and the United Nations Sustainable Development Goals (SDGs). We find that all land-based GGR options contribute positively to at least some NCPs and SDGs. Wetland restoration and SCS almost exclusively deliver positive impacts. A few GGR options, such as afforestation, BECCS, and biochar potentially impact negatively some NCPs and SDGs, particularly when implemented at scale, largely through competition for land. For those that present risks or are least understood, more research is required, and demonstration projects need to proceed with caution. For options that present low risks and provide cobenefits, implementation can proceed more rapidly following no-regrets principles.},
author = {Smith, Pete and Adams, Justin and Beerling, David J. and Beringer, Tim and Calvin, Katherine V. and Fuss, Sabine and Griscom, Bronson and Hagemann, Nikolas and Kammann, Claudia and Kraxner, Florian and Minx, Jan C. and Popp, Alexander and Renforth, Phil and {Vicente Vicente}, Jose Luis and Keesstra, Saskia},
doi = {10.1146/annurev-environ-101718-033129},
issn = {1543-5938},
journal = {Annual Review of Environment and Resources},
month = {oct},
number = {1},
pages = {255--286},
title = {{Land-Management Options for Greenhouse Gas Removal and Their Impacts on Ecosystem Services and the Sustainable Development Goals}},
url = {https://www.annualreviews.org/doi/10.1146/annurev-environ-101718-033129},
volume = {44},
year = {2019}
}
@article{Snider2015,
author = {Snider, David M. and Venkiteswaran, Jason J. and Schiff, Sherry L. and Spoelstra, John},
doi = {10.1371/journal.pone.0118954},
editor = {Hu, Shuijin},
issn = {1932-6203},
journal = {PLOS ONE},
month = {mar},
number = {3},
pages = {e0118954},
title = {{From the Ground Up: Global Nitrous Oxide Sources are Constrained by Stable Isotope Values}},
url = {https://dx.plos.org/10.1371/journal.pone.0118954},
volume = {10},
year = {2015}
}
@article{Song2019,
author = {Song, Jian and Wan, Shiqiang and Piao, Shilong and Knapp, Alan K. and Classen, Aim{\'{e}}e T. and Vicca, Sara and Ciais, Philippe and Hovenden, Mark J. and Leuzinger, Sebastian and Beier, Claus and Kardol, Paul and Xia, Jianyang and Liu, Qiang and Ru, Jingyi and Zhou, Zhenxing and Luo, Yiqi and Guo, Dali and {Adam Langley}, J. and Zscheischler, Jakob and Dukes, Jeffrey S. and Tang, Jianwu and Chen, Jiquan and Hofmockel, Kirsten S. and Kueppers, Lara M. and Rustad, Lindsey and Liu, Lingli and Smith, Melinda D. and Templer, Pamela H. and {Quinn Thomas}, R. and Norby, Richard J. and Phillips, Richard P. and Niu, Shuli and Fatichi, Simone and Wang, Yingping and Shao, Pengshuai and Han, Hongyan and Wang, Dandan and Lei, Lingjie and Wang, Jiali and Li, Xiaoming Xiaona and Zhang, Qian and Li, Xiaoming Xiaona and Su, Fanglong and Liu, Bin and Yang, Fan and Ma, Gaigai and Li, Guoyong and Liu, Yinzhan Yanchun and Liu, Yinzhan Yanchun and Yang, Zhongling and Zhang, Kesheng and Miao, Yuan and Hu, Mengjun and Yan, Chuang and Zhang, Ang and Zhong, Mingxing and Hui, Yan and Li, Ying and Zheng, Mengmei},
doi = {10.1038/s41559-019-0958-3},
issn = {2397-334X},
journal = {Nature Ecology {\&} Evolution},
month = {sep},
number = {9},
pages = {1309--1320},
title = {{A meta-analysis of 1,119 manipulative experiments on terrestrial carbon-cycling responses to global change}},
url = {http://www.nature.com/articles/s41559-019-0958-3},
volume = {3},
year = {2019}
}
@article{Song2018,
author = {Song, Xiaotong and Liu, Min and Ju, Xiaotang and Gao, Bing and Su, Fang and Chen, Xinping and Rees, Robert M},
doi = {10.1021/acs.est.8b03931},
issn = {0013-936X},
journal = {Environmental Science {\&} Technology},
month = {nov},
number = {21},
pages = {12504--12513},
title = {{Nitrous Oxide Emissions Increase Exponentially When Optimum Nitrogen Fertilizer Rates Are Exceeded in the North China Plain}},
url = {https://pubs.acs.org/doi/10.1021/acs.est.8b03931},
volume = {52},
year = {2018}
}
@article{Sonntag2015,
abstract = {Studies on the global climatic effects of afforestation have mainly focused on the carbon sequestration potential of plausible scenarios while neglecting biogeophysical effects or were based on highly idealised afforestation scenarios. Here we assess the reduction potential for the atmospheric CO2 concentration and possible consequences for the global climate of following a strong reforestation scenario during this century taking into account both biogeochemical and biogeophysical effects. We perform simulations using the Max Planck Institute for Meteorology Earth System Model (MPI-ESM), forced by anthropogenic emissions according to the Representative Concentration Pathway (RCP) 8.5, but using land use transitions according to RCP 4.5. Thereby we are able to isolate the effects of land use changes in this scenario in which agricultural intensification leads to abandonment of agricultural areas and a regrowth of forest of about 8 million km2 in our model. We find that this reforestation reduces the atmospheric CO2 concentration by about 85 ppm by the end of the century as compared to RCP 8.5. This value is higher than previous estimates for plausible reforestation scenarios, mostly because the CO2 fertilisation effect on the terrestrial vegetation has not been accounted for in previous studies. Due to the lower CO2 concentration the global mean temperature increase is reduced by about 0.27 K. Regionally the simulated effect may exceed 2 K, but the largest annual mean cooling signal occurs in only sparsely populated regions. Concerning temperature extremes, however, the effect can also be large in densely populated areas, mostly caused by local biogeophysical effects of the vegetation changes. Thus, we conclude that the mitigation potential of reforestation is higher than previously thought, the need for adaptation in many regions of the world is still strong, but temperature extremes may be reduced.},
author = {Sonntag, Sebastian and Pongratz, Julia and Reick, Christian H. and Schmidt, Hauke},
doi = {10.1002/2016GL068824},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {jun},
number = {12},
pages = {6546--6553},
title = {{Reforestation in a high-CO2 world-Higher mitigation potential than expected, lower adaptation potential than hoped for}},
url = {http://doi.wiley.com/10.1002/2016GL068824},
volume = {43},
year = {2016}
}
@article{Sonntag2018a,
abstract = {To contribute to a quantitative comparison of climate engineering (CE) methods, we assess atmosphere-, ocean-, and land-based CE measures with respect to Earth system effects consistently within one comprehensive model. We use the Max Planck Institute Earth System Model (MPI-ESM) with prognostic carbon cycle to compare solar radiation management (SRM) by stratospheric sulfur injection and two carbon dioxide removal methods: afforestation and ocean alkalinization. The CE model experiments are designed to offset the effect of fossil-fuel burning on global mean surface air temperature under the RCP8.5 scenario to follow or get closer to the RCP4.5 scenario. Our results show the importance of feedbacks in the CE effects. For example, as a response to SRM the land carbon uptake is enhanced by 92 Gt by the year 2100 compared to the reference RCP8.5 scenario due to reduced soil respiration thus reducing atmospheric CO2. Furthermore, we show that normalizations allow for a better comparability of different CE methods. For example, we find that due to compensating processes such as biogeophysical effects of afforestation more carbon needs to be removed from the atmosphere by afforestation than by alkalinization to reach the same global warming reduction. Overall, we illustrate how different CE methods affect the components of the Earth system; we identify challenges arising in a CE comparison, and thereby contribute to developing a framework for a comparative assessment of CE.},
author = {Sonntag, Sebastian and {Ferrer Gonz{\'{a}}lez}, Miriam and Ilyina, Tatiana and Kracher, Daniela and Nabel, Julia E. M. S. and Niemeier, Ulrike and Pongratz, Julia and Reick, Christian H. and Schmidt, Hauke},
doi = {10.1002/2017EF000620},
issn = {23284277},
journal = {Earth's Future},
language = {en},
month = {feb},
number = {2},
pages = {149--168},
title = {{Quantifying and Comparing Effects of Climate Engineering Methods on the Earth System}},
url = {http://doi.wiley.com/10.1002/2017EF000620},
volume = {6},
year = {2018}
}
@article{Spafford,
abstract = {The Transient Climate Response to Cumulative CO2 Emissions (TCRE) is the proportionality between global temperature change and cumulative CO2 emissions. The TCRE implies a finite quantity of CO2 emissions, or carbon budget, consistent with a given temperature change limit. The uncertainty of the TCRE is often assumed be normally distributed, but this assumption has yet to be validated. We calculated the TCRE using a zero-dimensional ocean diffusive model and a Monte-Carlo error propagation (n = 10 000 000) randomly drawing from probability density functions of the climate feedback parameter, the land-borne fraction of carbon, radiative forcing from an e-fold increase in CO2 concentration, effective ocean diffusivity, and the ratio of sea to global surface temperature change. The calculated TCRE has a positively skewed distribution, ranging from 1.1 to 2.9 K EgC-1 (5{\%}-95{\%} confidence), with a mean and median value of 1.9 and 1.8 K EgC-1. The calculated distribution of the TCRE is well described by a log-normal distribution. The CO2-only carbon budget compatible with 2 °C warming is 1100 PgC, ranging from 700 to 1800 PgC (5{\%}-95{\%} confidence) estimated using a simplified model of ocean dynamics. Climate sensitivity is the most influential Earth System parameter on the TCRE, followed by the land-borne fraction of carbon, radiative forcing from an e-fold increase in CO2, effective ocean diffusivity, and the ratio of sea to global surface temperature change. While the uncertainty of the TCRE is considerable, the use of a log-normal distribution may improve estimations of the TCRE and associated carbon budgets.},
author = {Spafford, Lynsay and Macdougall, Andrew H.},
doi = {10.1088/1748-9326/ab6d7b},
issn = {17489326},
journal = {Environmental Research Letters},
keywords = {carbon budgets,carbon-climate feedback,climate sensitivity,land-borne fraction of carbon,transient climate response to cumulative CO2 emiss},
number = {3},
pages = {034044},
title = {{Quantifying the probability distribution function of the transient climate response to cumulative CO2 emissions}},
volume = {15},
year = {2020}
}
@article{Spring2020,
abstract = {On interannual timescales the growth rate of atmospheric CO2 is largely controlled by the response of the land and ocean carbon sinks to climate variability. Yet, it is unknown to what extent this variability limits the predictability of atmospheric CO2 variations. Using perfect-model Earth System Model simulations, we show that variations in atmospheric CO2 are potentially predictable for 3 years. We find a 2-year predictability horizon for global oceanic CO2 flux with longer regional predictability of up to 7 years. The 2-year predictability horizon of terrestrial CO2 flux originates in the tropics and midlatitudes. With the predictability of the isolated effects of land and ocean carbon sink on atmospheric CO2 of 5 and 12 years respectively, land dampens the overall predictability of atmospheric CO2 variations. Our research shows the potential of Earth System Model-based predictions to forecast multiyear variations in atmospheric CO2.},
author = {Spring, Aaron and Ilyina, Tatiana},
doi = {10.1029/2019GL085311},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Earth System Model,atmospheric CO2,carbon fluxes,decadal predictability,internal variability},
month = {may},
number = {9},
pages = {e2019GL085311},
title = {{Predictability Horizons in the Global Carbon Cycle Inferred From a Perfect-Model Framework}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2019GL085311},
volume = {47},
year = {2020}
}
@article{Stanley2016,
author = {Stanley, Emily H. and Casson, Nora J. and Christel, Samuel T. and Crawford, John T. and Loken, Luke C. and Oliver, Samantha K.},
doi = {10.1890/15-1027},
issn = {00129615},
journal = {Ecological Monographs},
month = {may},
number = {2},
pages = {146--171},
title = {{The ecology of methane in streams and rivers: patterns, controls, and global significance}},
url = {http://doi.wiley.com/10.1890/15-1027},
volume = {86},
year = {2016}
}
@article{Staver230,
abstract = {Theoretically, fire{\{}$\backslash$textendash{\}}tree cover feedbacks can maintain savanna and forest as alternative stable states. However, the global extent of fire-driven discontinuities in tree cover is unknown, especially accounting for seasonality and soils. We use tree cover, climate, fire, and soils data sets to show that tree cover is globally discontinuous. Climate influences tree cover globally but, at intermediate rainfall (1000 to 2500 millimeters) with mild seasonality (less than 7 months), tree cover is bimodal, and only fire differentiates between savanna and forest. These may be alternative states over large areas, including parts of Amazonia and the Congo. Changes in biome distributions, whether at the cost of savanna (due to fragmentation) or forest (due to climate), will be neither smooth nor easily reversible.},
annote = {added by A.Eliseev 25.01.2019},
author = {Staver, A Carla and Archibald, Sally and Levin, Simon A},
doi = {10.1126/science.1210465},
issn = {0036-8075},
journal = {Science},
month = {oct},
number = {6053},
pages = {230--232},
publisher = {American Association for the Advancement of Science},
title = {{The global extent and determinants of savanna and forest as alternative biome states}},
url = {http://science.sciencemag.org/content/334/6053/230 http://www.sciencemag.org/cgi/doi/10.1126/science.1210465},
volume = {334},
year = {2011}
}
@article{Steele1992,
abstract = {MEASUREMENTS of methane in modern air1–8 and in air trapped in ice cores9–12 have shown convincingly that the abundance of atmospheric methane has been rising since the Industrial Revolution. This is a matter of concern because of the important role of methane in determining the radiative balance and chemical composition of the atmosphere13. The causes of this increase have not been identified unambiguously because of uncertainties in our understanding of the global budget of atmospheric methane14 and in how it is changing with time. Here we report on measurements of atmospheric methane from an extensive global network of flask sampling sites, which reveal that, although methane continues to accumulate in the atmosphere, there has been a substantial slowing of the global accumulation rate between 1983 and 1990. If this deceleration continues steadily, global methane concentrations will reach a maximum around the year 2006. Our results hint that changes in methane emissions in the latitude band 30–90° N may be of particular significance to this trend.},
author = {Steele, L. P. and Dlugokencky, E. J. and Lang, P. M. and Tans, P. P. and Martin, R. C. and Masarie, K. A.},
doi = {10.1038/358313a0},
issn = {0028-0836},
journal = {Nature},
month = {jul},
number = {6384},
pages = {313--316},
publisher = {Nature Publishing Group},
title = {{Slowing down of the global accumulation of atmospheric methane during the 1980s}},
url = {http://www.nature.com/articles/358313a0},
volume = {358},
year = {1992}
}
@article{Steffen2018,
abstract = {We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System—biosphere, climate, and societies—and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values.},
author = {Steffen, Will and Rockstr{\"{o}}m, Johan and Richardson, Katherine and Lenton, Timothy M and Folke, Carl and Liverman, Diana and Summerhayes, Colin P and Barnosky, Anthony D and Cornell, Sarah E and Crucifix, Michel and Donges, Jonathan F and Fetzer, Ingo and Lade, Steven J and Scheffer, Marten and Winkelmann, Ricarda and Schellnhuber, Hans Joachim},
doi = {10.1073/pnas.1810141115},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Anthropocene,Earth System trajectories,biosphere feedbacks,climate change,tipping elements},
month = {aug},
number = {33},
pages = {8252--8259},
pmid = {30082409},
publisher = {National Academy of Sciences},
title = {{Trajectories of the Earth System in the Anthropocene}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/30082409 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC6099852 http://www.pnas.org/lookup/doi/10.1073/pnas.1810141115},
volume = {115},
year = {2018}
}
@article{Steinacher2016,
abstract = {Abstract. Information on the relationship between cumulative fossil CO2 emissions and multiple climate targets is essential to design emission mitigation and climate adaptation strategies. In this study, the transient response of a climate or environmental variable per trillion tonnes of CO2 emissions, termed TRE, is quantified for a set of impact-relevant climate variables and from a large set of multi-forcing scenarios extended to year 2300 towards stabilization. An ∼ 1000-member ensemble of the Bern3D-LPJ carbon–climate model is applied and model outcomes are constrained by 26 physical and biogeochemical observational data sets in a Bayesian, Monte Carlo-type framework. Uncertainties in TRE estimates include both scenario uncertainty and model response uncertainty. Cumulative fossil emissions of 1000 Gt C result in a global mean surface air temperature change of 1.9 °C (68 {\%} confidence interval (c.i.): 1.3 to 2.7 °C), a decrease in surface ocean pH of 0.19 (0.18 to 0.22), and a steric sea level rise of 20 cm (13 to 27 cm until 2300). Linearity between cumulative emissions and transient response is high for pH and reasonably high for surface air and sea surface temperatures, but less pronounced for changes in Atlantic meridional overturning, Southern Ocean and tropical surface water saturation with respect to biogenic structures of calcium carbonate, and carbon stocks in soils. The constrained model ensemble is also applied to determine the response to a pulse-like emission and in idealized CO2-only simulations. The transient climate response is constrained, primarily by long-term ocean heat observations, to 1.7 °C (68 {\%} c.i.: 1.3 to 2.2 °C) and the equilibrium climate sensitivity to 2.9 °C (2.0 to 4.2 °C). This is consistent with results by CMIP5 models but inconsistent with recent studies that relied on short-term air temperature data affected by natural climate variability.},
author = {Steinacher, M. and Joos, F.},
doi = {10.5194/bg-13-1071-2016},
isbn = {1726-4170},
issn = {1726-4189},
journal = {Biogeosciences},
month = {feb},
number = {4},
pages = {1071--1103},
title = {{Transient Earth system responses to cumulative carbon dioxide emissions: linearities, uncertainties, and probabilities in an observation-constrained model ensemble}},
url = {https://www.biogeosciences.net/13/1071/2016/},
volume = {13},
year = {2016}
}
@article{Steinacher2009,
author = {Steinacher, M and Joos, F and Fr{\"{o}}licher, T L and Plattner, G.-K. and Doney, S C},
doi = {10.5194/bg-6-515-2009},
journal = {Biogeosciences},
number = {4},
pages = {515--533},
title = {{Imminent ocean acidification in the Arctic projected with the NCAR global coupled carbon cycle–climate model}},
url = {https://bg.copernicus.org/articles/6/515/2009/},
volume = {6},
year = {2009}
}
@article{Stenzel2019,
abstract = {Limiting mean global warming to well below 2 °C will probably require substantial negative emissions (NEs) within the 21st century. To achieve these, bioenergy plantations with subsequent carbon capture and storage (BECCS) may have to be implemented at a large scale. Irrigation of these plantations might be necessary to increase the yield, which is likely to put further pressure on already stressed freshwater systems. Conversely, the potential of bioenergy plantations (BPs) dedicated to achieving NEs through CO2 assimilation may be limited in regions with low freshwater availability. This paper provides a first-order quantification of the biophysical potentials of BECCS as a negative emission technology contribution to reaching the 1.5 °C warming target, as constrained by associated water availabilities and requirements. Using a global biosphere model, we analyze the availability of freshwater for irrigation of BPs designed to meet the projected NEs to fulfill the 1.5 °C target, spatially explicitly on areas not reserved for ecosystem conservation or agriculture. We take account of the simultaneous water demands for agriculture, industries, and households and also account for environmental flow requirements (EFRs) needed to safeguard aquatic ecosystems. Furthermore, we assess to what extent different forms of improved water management on the suggested BPs and on cropland may help to reduce the freshwater abstractions. Results indicate that global water withdrawals for irrigation of BPs range between ∼400 and ∼3000 km3 yr-1, depending on the scenario and the conversion efficiency of the carbon capture and storage process. Consideration of EFRs reduces the NE potential significantly, but can partly be compensated for by improved on-field water management.},
author = {Stenzel, Fabian and Gerten, Dieter and Werner, Constanze and J{\"{a}}germeyr, Jonas},
doi = {10.1088/1748-9326/ab2b4b},
issn = {1748-9326},
journal = {Environmental Research Letters},
keywords = {BECCS,bioenergy plantations,climate change,environmental flow requirements,irrigation,negative emissions,water demand},
month = {jul},
number = {8},
pages = {084001},
publisher = {IOP Publishing},
title = {{Freshwater requirements of large-scale bioenergy plantations for limiting global warming to 1.5 °C}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/ab2b4b},
volume = {14},
year = {2019}
}
@article{Stenzel2021,
abstract = {Bioenergy with carbon capture and storage (BECCS) is considered an important negative emissions (NEs) technology, but might involve substantial irrigation on biomass plantations. Potential water stress resulting from the additional withdrawals warrants evaluation against the avoided climate change impact. Here we quantitatively assess potential side effects of BECCS with respect to water stress by disentangling the associated drivers (irrigated biomass plantations, climate, land use patterns) using comprehensive global model simulations. By considering a widespread use of irrigated biomass plantations, global warming by the end of the 21st century could be limited to 1.5 °C compared to a climate change scenario with 3 °C. However, our results suggest that both the global area and population living under severe water stress in the BECCS scenario would double compared to today and even exceed the impact of climate change. Such side effects of achieving substantial NEs would come as an extra pressure in an already water-stressed world and could only be avoided if sustainable water management were implemented globally.},
author = {Stenzel, Fabian and Greve, Peter and Lucht, Wolfgang and Tramberend, Sylvia and Wada, Yoshihide and Gerten, Dieter},
doi = {10.1038/s41467-021-21640-3},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {1512},
publisher = {Springer US},
title = {{Irrigation of biomass plantations may globally increase water stress more than climate change}},
url = {http://dx.doi.org/10.1038/s41467-021-21640-3 http://www.nature.com/articles/s41467-021-21640-3},
volume = {12},
year = {2021}
}
@article{gmd-9-1977-2016,
abstract = {Abstract. A one-dimensional (1-D) model for an enclosed basin (lake) is presented, which reproduces temperature, horizontal velocities, oxygen, carbon dioxide and methane in the basin. All prognostic variables are treated in a unified manner via a generic 1-D transport equation for horizontally averaged property. A water body interacts with underlying sediments. These sediments are represented by a set of vertical columns with heat, moisture and CH4 transport inside. The model is validated vs. a comprehensive observational data set gathered at Kuivaj{\"{a}}rvi Lake (southern Finland), demonstrating a fair agreement. The value of a key calibration constant, regulating the magnitude of methane production in sediments, corresponded well to that obtained from another two lakes. We demonstrated via surface seiche parameterization that the near-bottom turbulence induced by surface seiches is likely to significantly affect CH4 accumulation there. Furthermore, our results suggest that a gas transfer through thermocline under intense internal seiche motions is a bottleneck in quantifying greenhouse gas dynamics in dimictic lakes, which calls for further research.},
author = {Stepanenko, Victor and Mammarella, Ivan and Ojala, Anne and Miettinen, Heli and Lykosov, Vasily and Vesala, Timo},
doi = {10.5194/gmd-9-1977-2016},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {may},
number = {5},
pages = {1977--2006},
title = {{LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes}},
url = {https://www.geosci-model-dev.net/9/1977/2016/},
volume = {9},
year = {2016}
}
@article{Sterman2018,
abstract = {Bioenergy is booming as nations seek to cut their greenhouse gas emissions. The European Union declared biofuels to be carbon-neutral, triggering a surge in wood use. But do biofuels actually reduce emissions? A molecule of CO2 emitted today has the same impact on radiative forcing whether it comes from coal or biomass. Biofuels can only reduce atmospheric CO2 over time through post-harvest increases in net primary production (NPP). The climate impact of biofuels therefore depends on CO2 emissions from combustion of biofuels versus fossil fuels, the fate of the harvested land and dynamics of NPP. Here we develop a model for dynamic bioenergy lifecycle analysis. The model tracks carbon stocks and fluxes among the atmosphere, biomass, and soils, is extensible to multiple land types and regions, and runs in ≈1s, enabling rapid, interactive policy design and sensitivity testing. We simulate substitution of wood for coal in power generation, estimating the parameters governing NPP and other fluxes using data for forests in the eastern US and using published estimates for supply chain emissions. Because combustion and processing efficiencies for wood are less than coal, the immediate impact of substituting wood for coal is an increase in atmospheric CO2 relative to coal. The payback time for this carbon debt ranges from 44–104 years after clearcut, depending on forest type—assuming the land remains forest. Surprisingly, replanting hardwood forests with fast-growing pine plantations raises the CO2 impact of wood because the equilibrium carbon density of plantations is lower than natural forests. Further, projected growth in wood harvest for bioenergy would increase atmospheric CO2 for at least a century because new carbon debt continuously exceeds NPP. Assuming biofuels are carbon neutral may worsen irreversible impacts of climate change before benefits accrue. Instead, explicit dynamic models should be used to assess the climate impacts of biofuels.},
author = {Sterman, John D and Siegel, Lori and Rooney-Varga, Juliette N},
doi = {10.1088/1748-9326/aaa512},
issn = {1748-9326},
journal = {Environmental Research Letters},
number = {1},
pages = {15007},
publisher = {IOP Publishing},
title = {{Does replacing coal with wood lower CO2 emissions? Dynamic lifecycle analysis of wood bioenergy}},
volume = {13},
year = {2018}
}
@article{Stern1996,
abstract = {This paper provides the first time series estimates of global anthropogenic methane emissions from the mid-19th century to the present. Our purpose is to provide time series estimates of anthropogenic methane emissions for global climate models estimated or calibrated using historical time series data. Previous estimates of methane emissions include “top-down” (deconvolution) estimates of total emissions, estimates of global anthropogenic emissions for the 16th century, and various estimates of anthropogenic and natural emissions in the 1980s and 1990s. This study uses previously published point estimates for the 16th century and the 1980s and early 1990s and a variety of historical time series of proxy variables to estimate a time series of global anthropogenic methane emissions. We find that anthropogenic methane emissions have increased from about 80 million tonnes per annum in 1860 to about 380 million tonnes in 1990. The relative importance of various emission sources changes over time. The rate of increase now may be slowing. A comparison with the estimates generated by Khalil and Rasmussen suggests that natural sources of methane have declined over the period. There are, however, great uncertainties in these estimates which future research may be able to reduce.},
author = {Stern, David I. and Kaufmann, Robert K.},
doi = {10.1016/0045-6535(96)00157-9},
issn = {00456535},
journal = {Chemosphere},
month = {jul},
number = {1},
pages = {159--176},
publisher = {Pergamon},
title = {{Estimates of global anthropogenic methane emissions 1860–1993}},
url = {https://www.sciencedirect.com/science/article/pii/0045653596001579?via{\%}3Dihub http://linkinghub.elsevier.com/retrieve/pii/0045653596001579},
volume = {33},
year = {1996}
}
@article{Stevenson2020,
author = {Stevenson, David S and Zhao, Alcide and Naik, Vaishali and O'Connor, Fiona M and Tilmes, Simone and Zeng, Guang and Murray, Lee T and Collins, William J and Griffiths, Paul T and Shim, Sungbo and Horowitz, Larry W and Sentman, Lori T and Emmons, Louisa},
doi = {10.5194/acp-20-12905-2020},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {nov},
number = {21},
pages = {12905--12920},
publisher = {Copernicus Publications},
title = {{Trends in global tropospheric hydroxyl radical and methane lifetime since 1850 from AerChemMIP}},
url = {https://acp.copernicus.org/articles/20/12905/2020/},
volume = {20},
year = {2020}
}
@article{Stocker2013a,
abstract = {Atmospheric concentrations of the three important greenhouse gases (GHGs) CO2, CH4 and N2O are mediated by processes in the terrestrial biosphere that are sensitive to climate and CO2. This leads to feedbacks between climate and land and has contributed to the sharp rise in atmospheric GHG concentrations since pre-industrial times. Here, we apply a process-based model to reproduce the historical atmospheric N2O and CH4 budgets within their uncertainties and apply future scenarios for climate, land-use change and reactive nitrogen (Nr) inputs to investigate future GHG emissions and their feedbacks with climate in a consistent and comprehensive framework1. Results suggest that in a business-as-usual scenario, terrestrial N2O and CH4 emissions increase by 80 and 45{\%}, respectively, and the land becomes a net source of C by AD 2100. N2O and CH4 feedbacks imply an additional warming of 0.4–0.5 °C by AD 2300; on top of 0.8–1.0 °C caused by terrestrial carbon cycle and Albedo feedbacks. The land biosphere represents an increasingly positive feedback to anthropogenic climate change and amplifies equilibrium climate sensitivity by 22–27{\%}. Strong mitigation limits the increase of terrestrial GHG emissions and prevents the land biosphere from acting as an increasingly strong amplifier to anthropogenic climate change.},
author = {Stocker, Benjamin D and Roth, Raphael and Joos, Fortunat and Spahni, Renato and Steinacher, Marco and Zaehle, Soenke and Bouwman, Lex and Xu-Ri and Prentice, Iain Colin},
doi = {10.1038/nclimate1864},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jul},
number = {7},
pages = {666--672},
publisher = {Nature Publishing Group},
title = {{Multiple greenhouse-gas feedbacks from the land biosphere under future climate change scenarios}},
url = {http://www.nature.com/articles/nclimate1864},
volume = {3},
year = {2013}
}
@article{Stocker2015,
abstract = {Abstract. The quantification of CO2 emissions from anthropogenic land use and land use change (eLUC) is essential to understand the drivers of the atmospheric CO2 increase and to inform climate change mitigation policy. Reported values in synthesis reports are commonly derived from different approaches (observation-driven bookkeeping and process-modelling) but recent work has emphasized that inconsistencies between methods may imply substantial differences in eLUC estimates. However, a consistent quantification is lacking and no concise modelling protocol for the separation of primary and secondary components of eLUC has been established. Here, we review differences of eLUC quantification methods and apply an Earth System Model (ESM) of Intermediate Complexity to quantify them. We find that the magnitude of effects due to merely conceptual differences between ESM and offline vegetation model-based quantifications is {\~{}} 20 {\%} for today. Under a future business-as-usual scenario, differences tend to increase further due to slowing land conversion rates and an increasing impact of altered environmental conditions on land-atmosphere fluxes. We establish how coupled Earth System Models may be applied to separate secondary component fluxes of eLUC arising from the replacement of potential C sinks/sources and the land use feedback and show that secondary fluxes derived from offline vegetation models are conceptually and quantitatively not identical to either, nor their sum. Therefore, we argue that synthesis studies should resort to the "least common denominator" of different methods, following the bookkeeping approach where only primary land use emissions are quantified under the assumption of constant environmental boundary conditions.},
author = {Stocker, B. D. and Joos, F.},
doi = {10.5194/esd-6-731-2015},
issn = {2190-4987},
journal = {Earth System Dynamics},
month = {nov},
number = {2},
pages = {731--744},
title = {{Quantifying differences in land use emission estimates implied by definition discrepancies}},
url = {https://www.earth-syst-dynam.net/6/731/2015/},
volume = {6},
year = {2015}
}
@article{Stocker2017a,
abstract = {CO 2 emissions from preindustrial land-use change (LUC) are sub-ject to large uncertainties. Although atmospheric CO 2 records sug-gest only a small land carbon (C) source since 5,000 y before present (5 kyBP), the concurrent C sink by peat buildup could mask large early LUC emissions. Here, we combine updated continu-ous peat C reconstructions with the land C balance inferred from double deconvolution analyses of atmospheric CO 2 and $\delta$ 13 C at different temporal scales to investigate the terrestrial C budget of the Holocene and the last millennium and constrain LUC emis-sions. LUC emissions are estimated with transient model simu-lations for diverging published scenarios of LU area change and shifting cultivation. Our results reveal a large terrestrial nonpeat-land C source after the Mid-Holocene (66 ± 25 PgC at 7–5 kyBP and 115 ± 27 PgC at 5–3 kyBP). Despite high simulated per-capita CO 2 emissions from LUC in early phases of agricultural development, humans emerge as a driver with dominant global C cycle impacts only in the most recent three millennia. Sole anthropogenic causes for particular variations in the CO 2 record (∼20 ppm rise after 7 kyBP and ∼10 ppm fall between 1500 CE and 1600 CE) are not supported. This analysis puts a strong constraint on preindustrial vs. industrial-era LUC emissions and suggests that upper-end sce-narios for the extent of agricultural expansion before 1850 CE are not compatible with the C budget thereafter. carbon cycle | Anthropocene | agriculture | peatland | ice core},
author = {Stocker, Benjamin David and Yu, Zicheng and Massa, Charly and Joos, Fortunat},
doi = {10.1073/pnas.1613889114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {feb},
number = {7},
pages = {1492--1497},
pmid = {28137849},
title = {{Holocene peatland and ice-core data constraints on the timing and magnitude of CO2 emissions from past land use}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1613889114},
volume = {114},
year = {2017}
}
@incollection{RN5126,
address = {Cambridge, United Kingdom and New York, NY, USA},
author = {Stocker, T F and Qin, D and Plattner, G.-K. and Alexander, L V and Allen, S K and Bindoff, N L and Bréon, F.-M. and Church, J A and Cubasch, U and Emori, S and Forster, P and Friedlingstein, P and Gillett, N and Gregory, J M and Hartmann, D L and Jansen, E and Kirtman, B and Knutti, R and Kumar, K Krishna and Lemke, P and Marotzke, J and Masson-Delmotte, V and Meehl, G A and Mokhov, I I and Piao, S and Ramaswamy, V and Randall, D and Rhein, M and Rojas, M and Sabine, C and Shindell, D and Talley, L D and Vaughan, D G and Xie, S.-P.},
booktitle = {Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change},
chapter = {TS},
doi = {10.1017/CBO9781107415324.005},
editor = {Stocker, T.F. and Qin, D. and Plattner, G.-K. and Tignor, M. and Allen, S K and Boschung, A and Nauels, A and Xia, Y. and Bex, V. and Midgley, P. M.},
isbn = {9781107661820},
pages = {33--115},
publisher = {Cambridge University Press},
title = {{Technical Summary}},
type = {Book Section},
url = {https://www.ipcc.ch/report/ar5/wg1},
year = {2013}
}
@article{Stocker2019,
abstract = {Satellite retrievals of information about the Earth's surface are widely used to monitor global terrestrial photosynthesis and primary production and to examine the ecological impacts of droughts. Methods for estimating photosynthesis from space commonly combine information on vegetation greenness, incoming radiation, temperature and atmospheric demand for water (vapour-pressure deficit), but do not account for the direct effects of low soil moisture. They instead rely on vapour-pressure deficit as a proxy for dryness, despite widespread evidence that soil moisture deficits have a direct impact on vegetation, independent of vapour-pressure deficit. Here, we use a globally distributed measurement network to assess the effect of soil moisture on photosynthesis, and identify a common bias in an ensemble of satellite-based estimates of photosynthesis that is governed by the magnitude of soil moisture effects on photosynthetic light-use efficiency. We develop methods to account for the influence of soil moisture and estimate that soil moisture effects reduce global annual photosynthesis by {\~{}}15{\%}, increase interannual variability by more than 100{\%} across 25{\%} of the global vegetated land surface, and amplify the impacts of extreme events on primary production. These results demonstrate the importance of soil moisture effects for monitoring carbon-cycle variability and drought impacts on vegetation productivity from space.},
author = {Stocker, Benjamin D. and Zscheischler, Jakob and Keenan, Trevor F. and Prentice, I. Colin and Seneviratne, Sonia I. and Pe{\~{n}}uelas, Josep},
doi = {10.1038/s41561-019-0318-6},
issn = {17520908},
journal = {Nature Geoscience},
number = {4},
pages = {264--270},
publisher = {Springer US},
title = {{Drought impacts on terrestrial primary production underestimated by satellite monitoring}},
url = {http://dx.doi.org/10.1038/s41561-019-0318-6},
volume = {12},
year = {2019}
}
@article{Stott2019a,
author = {Stott, Lowell D and Davy, Bryan and Shao, Jun and Coffin, Richard and Pecher, Ingo and Neil, Helen and Rose, Paula and Bialas, Joerg},
doi = {10.1029/2019PA003674},
issn = {2572-4517},
journal = {Paleoceanography and Paleoclimatology},
month = {nov},
number = {11},
pages = {1726--1743},
title = {{CO2 Release From Pockmarks on the Chatham Rise‐Bounty Trough at the Glacial Termination}},
url = {https://onlinelibrary.wiley.com/doi/10.1029/2019PA003674},
volume = {34},
year = {2019}
}
@article{Stott2019,
author = {Stott, Lowell D and Harazin, Kathleen M and {Quintana Krupinski}, Nadine B},
doi = {10.1088/1748-9326/aafe28},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {feb},
number = {2},
pages = {025007},
title = {{Hydrothermal carbon release to the ocean and atmosphere from the eastern equatorial Pacific during the last glacial termination}},
url = {http://stacks.iop.org/1748-9326/14/i=2/a=025007?key=crossref.695310fa5aa8fe3e2274eca6742be43a},
volume = {14},
year = {2019}
}
@article{Stramma2008,
abstract = {Oxygen-poor waters occupy large volumes of the intermediate-depth eastern tropical oceans. Oxygen-poor conditions have far-reaching impacts on ecosystems because important mobile macroorganisms avoid or cannot survive in hypoxic zones. Climate models predict declines in oceanic dissolved oxygen produced by global warming. We constructed 50-year time series of dissolved-oxygen concentration for select tropical oceanic regions by augmenting a historical database with recent measurements. These time series reveal vertical expansion of the intermediate-depth low-oxygen zones in the eastern tropical Atlantic and the equatorial Pacific during the past 50 years. The oxygen decrease in the 300- to 700-m layer is 0.09 to 0.34 micromoles per kilogram per year. Reduced oxygen levels may have dramatic consequences for ecosystems and coastal economies.},
author = {Stramma, Lothar and Johnson, Gregory C and Sprintall, Janet and Mohrholz, Volker},
doi = {10.1126/science.1153847},
issn = {0036-8075},
journal = {Science},
month = {may},
number = {5876},
pages = {655--658},
title = {{Expanding oxygen-minimum zones in the tropical oceans}},
url = {http://science.sciencemag.org/content/320/5876/655.abstract http://www.sciencemag.org/cgi/doi/10.1126/science.1153847},
volume = {320},
year = {2008}
}
@article{Strassburg2020,
abstract = {Extensive ecosystem restoration is increasingly seen as being central to conserving biodiversity1 and stabilizing the climate of the Earth2. Although ambitious national and global targets have been set, global priority areas that account for spatial variation in benefits and costs have yet to be identified. Here we develop and apply a multicriteria optimization approach that identifies priority areas for restoration across all terrestrial biomes, and estimates their benefits and costs. We find that restoring 15{\%} of converted lands in priority areas could avoid 60{\%} of expected extinctions while sequestering 299 gigatonnes of CO2—30{\%} of the total CO2 increase in the atmosphere since the Industrial Revolution. The inclusion of several biomes is key to achieving multiple benefits. Cost effectiveness can increase up to 13-fold when spatial allocation is optimized using our multicriteria approach, which highlights the importance of spatial planning. Our results confirm the vast potential contributions of restoration to addressing global challenges, while underscoring the necessity of pursuing these goals synergistically.},
author = {Strassburg, Bernardo B N and Iribarrem, Alvaro and Beyer, Hawthorne L and Cordeiro, Carlos Leandro and Crouzeilles, Renato and Jakovac, Catarina C and {Braga Junqueira}, Andr{\'{e}} and Lacerda, Eduardo and Latawiec, Agnieszka E and Balmford, Andrew and Brooks, Thomas M and Butchart, Stuart H M and Chazdon, Robin L and Erb, Karl-Heinz and Brancalion, Pedro and Buchanan, Graeme and Cooper, David and D{\'{i}}az, Sandra and Donald, Paul F and Kapos, Valerie and Lecl{\`{e}}re, David and Miles, Lera and Obersteiner, Michael and Plutzar, Christoph and {de M. Scaramuzza}, Carlos Alberto and Scarano, Fabio R and Visconti, Piero},
doi = {10.1038/s41586-020-2784-9},
issn = {1476-4687},
journal = {Nature},
number = {7831},
pages = {724--729},
title = {{Global priority areas for ecosystem restoration}},
url = {https://doi.org/10.1038/s41586-020-2784-9},
volume = {586},
year = {2020}
}
@article{doi:10.1002/2013GL058088,
abstract = {AbstractEstimates for circumpolar permafrost organic carbon (OC) storage suggest that this pool contains twice the amount of current atmospheric carbon. The Yedoma region sequestered substantial quantities of OC and is unique because its deep OC, which was incorporated into permafrost during ice age conditions. Rapid inclusion of labile organic matter into permafrost halted decomposition and resulted in a deep long-term sink. We show that the deep frozen OC in the Yedoma region consists of two distinct major subreservoirs: Yedoma deposits (late Pleistocene ice- and organic-rich silty sediments) and deposits formed in thaw-lake basins (generalized as thermokarst deposits). We quantified the OC pool based on field data and extrapolation using geospatial data sets to 83 + 61/−57 Gt for Yedoma deposits and to 128 + 99/−96 Gt for thermokarst deposits. The total Yedoma region 211 + 160/−153 Gt is a substantial amount of thaw-vulnerable OC that must be accounted for in global models.},
author = {Strauss, Jens and Schirrmeister, Lutz and Grosse, Guido and Wetterich, Sebastian and Ulrich, Mathias and Herzschuh, Ulrike and Hubberten, Hans-Wolfgang},
doi = {10.1002/2013GL058088},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Arctic,Yedoma,carbon cycle,climate feedback,frozen organic matter,thermokarst},
month = {dec},
number = {23},
pages = {6165--6170},
title = {{The deep permafrost carbon pool of the Yedoma region in Siberia and Alaska}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2013GL058088 http://doi.wiley.com/10.1002/2013GL058088},
volume = {40},
year = {2013}
}
@article{Strauss2017,
abstract = {Permafrost is a distinct feature of the terrestrial Arctic and is vulnerable to climate warming. Permafrost degrades in different ways, including deepening of a seasonally unfrozen surface and localized but rapid development of deep thaw features. Pleistocene ice-rich permafrost with syngenetic ice-wedges, termed Yedoma deposits, are widespread in Siberia, Alaska, and Yukon, Canada and may be especially prone to rapid-thaw processes. Freeze-locked organic matter in such deposits can be re-mobilized on short time-scales and contribute to a carbon-cycle climate feedback. Here we synthesize the characteristics and vulnerability of Yedoma deposits by synthesizing studies on the Yedoma origin and the associated organic carbon pool. We suggest that Yedoma deposits accumulated under periglacial weathering, transport, and deposition dynamics in non-glaciated regions during the late Pleistocene until the beginning of late glacial warming. The deposits formed due to a combination of aeolian, colluvial, nival, and alluvial deposition and simultaneous ground ice accumulation. We found up to 130 gigatons organic carbon in Yedoma, parts of which are well-preserved and available for fast decomposition after thaw. Based on incubation experiments, up to 10{\%} of the Yedoma carbon is considered especially decomposable and may be released upon thaw. The substantial amount of ground ice in Yedoma makes it highly vulnerable to disturbances such as thermokarst and thermo-erosion processes. Mobilization of permafrost carbon is expected to increase under future climate warming. Our synthesis results underline the need of accounting for Yedoma carbon stocks in next generation Earth-System-Models for a more complete representation of the permafrost-carbon feedback.},
author = {Strauss, Jens and Schirrmeister, Lutz and Grosse, Guido and Fortier, Daniel and Hugelius, Gustaf and Knoblauch, Christian and Romanovsky, Vladimir and Sch{\"{a}}del, Christina and {Schneider von Deimling}, Thomas and Schuur, Edward A.G. and Shmelev, Denis and Ulrich, Mathias and Veremeeva, Alexandra},
doi = {10.1016/j.earscirev.2017.07.007},
isbn = {1381-2386},
issn = {00128252},
journal = {Earth-Science Reviews},
keywords = {Arctic,Climate feedback,Greenhouse gas source,Late Pleistocene,Perennial frozen ground,Thermokarst},
month = {sep},
number = {July},
pages = {75--86},
publisher = {Elsevier},
title = {{Deep Yedoma permafrost: A synthesis of depositional characteristics and carbon vulnerability}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0012825217300508},
volume = {172},
year = {2017}
}
@article{Strefler2018,
abstract = {The chemical weathering of rocks currently absorbs about 1.1 Gt CO2 a−1 being mainly stored as bicarbonate in the ocean. An enhancement of this slow natural process could remove substantial amounts of CO2 from the atmosphere, aiming to offset some unavoidable anthropogenic emissions in order to comply with the Paris Agreement, while at the same time it may decrease ocean acidification. We provide the first comprehensive assessment of economic costs, energy requirements, technical parameterization, and global and regional carbon removal potential. The crucial parameters defining this potential are the grain size and weathering rates. The main uncertainties about the potential relate to weathering rates and rock mass that can be integrated into the soil. The discussed results do not specifically address the enhancement of weathering through microbial processes, feedback of geogenic nutrient release, and bioturbation. We do not only assess dunite rock, predominantly bearing olivine (in the form of forsterite) as the mineral that has been previously proposed to be best suited for carbon removal, but focus also on basaltic rock to minimize potential negative side effects. Our results show that enhanced weathering is an option for carbon dioxide removal that could be competitive already at 60 US {\$} t−1 CO2 removed for dunite, but only at 200 US {\$} t−1 CO2 removed for basalt. The potential carbon removal on cropland areas could be as large as 95 Gt CO2 a−1 for dunite and 4.9 Gt CO2 a−1 for basalt. The best suited locations are warm and humid areas, particularly in India, Brazil, South-East Asia and China, where almost 75{\%} of the global potential can be realized. This work presents a techno-economic assessment framework, which also allows for the incorporation of further processes.},
author = {Strefler, Jessica and Amann, Thorben and Bauer, Nico and Kriegler, Elmar and Hartmann, Jens},
doi = {10.1088/1748-9326/aaa9c4},
issn = {1748-9326},
journal = {Environmental Research Letters},
number = {3},
pages = {34010},
publisher = {IOP Publishing},
title = {{Potential and costs of carbon dioxide removal by enhanced weathering of rocks}},
volume = {13},
year = {2018}
}
@article{Strode2020,
author = {Strode, Sarah A. and Wang, James S. and Manyin, Michael and Duncan, Bryan and Hossaini, Ryan and Keller, Christoph A. and Michel, Sylvia E. and White, James W. C.},
doi = {10.5194/acp-20-8405-2020},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {jul},
number = {14},
pages = {8405--8419},
title = {{Strong sensitivity of the isotopic composition of methane to the plausible range of tropospheric chlorine}},
url = {https://acp.copernicus.org/articles/20/8405/2020/},
volume = {20},
year = {2020}
}
@article{Studer2018,
abstract = {A rise in the atmospheric CO2 concentration of {\~{}}20 parts per million over the course of the Holocene has long been recognized as exceptional among interglacials and is in need of explanation. Previous hypotheses involved natural or anthropogenic changes in terrestrial biomass, carbonate compensation in response to deglacial outgassing of oceanic CO2, and enhanced shallow water carbonate deposition. Here, we compile new and previously published fossil-bound nitrogen isotope records from the Southern Ocean that indicate a rise in surface nitrate concentration through the Holocene. When coupled with increasing or constant export production, these data suggest an acceleration of nitrate supply to the Southern Ocean surface from underlying deep water. This change would have weakened the ocean's biological pump that stores CO2 in the ocean interior, possibly explaining the Holocene atmospheric CO2 rise. Over the Holocene, the circum-North Atlantic region cooled, and the formation of North Atlantic Deep Water appears to have slowed. Thus, the ‘seesaw' in deep ocean ventilation between the North Atlantic and the Southern Ocean that has been invoked for millennial-scale events, deglaciations and the last interglacial period may have also operated, albeit in a more gradual form, over the Holocene.},
author = {Studer, Anja S. and Sigman, Daniel M. and Mart{\'{i}}nez-Garc{\'{i}}a, Alfredo and Th{\"{o}}le, Lena M. and Michel, Elisabeth and Jaccard, Samuel L. and Lippold, J{\"{o}}rg A. and Mazaud, Alain and Wang, Xingchen T. and Robinson, Laura F. and Adkins, Jess F. and Haug, Gerald H.},
doi = {10.1038/s41561-018-0191-8},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {oct},
number = {10},
pages = {756--760},
title = {{Increased nutrient supply to the Southern Ocean during the Holocene and its implications for the pre-industrial atmospheric CO2 rise}},
url = {https://www.nature.com/articles/s41561-018-0191-8 http://www.nature.com/articles/s41561-018-0191-8},
volume = {11},
year = {2018}
}
@article{Suess1955,
author = {Suess, H. E.},
doi = {10.1126/science.122.3166.415.b},
issn = {0036-8075},
journal = {Science},
month = {sep},
number = {3166},
pages = {415--417},
title = {{Radiocarbon Concentration in Modern Wood}},
volume = {122},
year = {1955}
}
@article{Sulman2019,
author = {Sulman, Benjamin N. and Shevliakova, Elena and Brzostek, Edward R. and Kivlin, Stephanie N. and Malyshev, Sergey and Menge, Duncan N.L. and Zhang, Xin},
doi = {10.1029/2018GB005973},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
month = {apr},
number = {4},
pages = {501--523},
title = {{Diverse mycorrhizal associations enhance terrestrial C storage in a global model}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GB005973},
volume = {33},
year = {2019}
}
@article{Sulpis2019,
abstract = {Abstract Results from a range of Earth System and climate models of various resolution run under high-CO2 emission scenarios challenge the paradigm that seafloor CaCO3 dissolution will grow in extent and intensify as ocean acidification develops over the next century. Under the “business as usual,” RCP8.5 scenario, CaCO3 dissolution increases in some areas of the deep ocean, such as the eastern central Pacific Ocean, but is projected to decrease in the Northern Pacific and abyssal Atlantic Ocean by the year 2100. The flux of CaCO3 to the seafloor and bottom-current speeds, both of which are expected to decrease globally through the 21st century, govern changes in benthic CaCO3 dissolution rates over 53{\%} and 31{\%} of the dissolving seafloor, respectively. Below the calcite compensation depth, a reduced CaCO3 flux to the CaCO3-free seabed modulates the amount of CaCO3 material dissolved at the sediment-water interface. Slower bottom-water circulation leads to thicker diffusive boundary layers above the sediment bed and a consequent stronger transport barrier to CaCO3 dissolution. While all investigated models predict a weakening of bottom current speeds over most of the seafloor by the end of the 21st century, strong discrepancies exist in the magnitude of the predicted speeds. Overall, the poor performance of most models in reproducing modern bottom-water velocities and CaCO3 rain rates coupled with the existence of large disparities in predicted bottom-water chemistry across models hampers our ability to robustly estimate the magnitude and temporal evolution of anthropogenic CaCO3 dissolution rates and the associated anthropogenic CO2 neutralization.},
author = {Sulpis, Olivier and Dufour, Carolina O and Trossman, David S and Fassbender, Andrea J and Arbic, Brian K and Boudreau, Bernard P and Dunne, John P and Mucci, Alfonso},
doi = {10.1029/2019GB006230},
journal = {Global Biogeochemical Cycles},
keywords = {CaCO3,RCP8.5,bottom currents,dissolution,ocean acidification},
number = {12},
pages = {1654--1673},
title = {{Reduced CaCO3 Flux to the Seafloor and Weaker Bottom Current Speeds Curtail Benthic CaCO3 Dissolution Over the 21st Century}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GB006230},
volume = {33},
year = {2019}
}
@article{Sun2020a,
abstract = {Prior studies of surface seawater CO2 partial pressure (pCO(2)) and air-sea CO2 fluxes have primarily been conducted on the eastern Bering Sea shelf area, with a paucity of data in the Bering Sea basin. In order to assess the surface variability and the air-sea CO2 fluxes for a more complete set of different regions, underway surface seawater pCO(2) and related parameters were investigated across the Bering Sea basin, slope and shelf in July 2010 during the 4th Chinese National Arctic Research Expedition (CHINARE). The surface pCO(2) exhibited large spatial variability and was observed to vary from 137 mu atm in the central Bering Strait to 481 mu atm in the western Bering Strait. In the central Bering Strait, the high supersaturation with respect to the atmospheric pCO(2) (378 +/- 2 mu atm) was driven by the upwelling event. The neutral or weak CO2 sink in the Bering Sea basin and eastern nearshore region were related to high nutrient low chlorophyll status and riverine input, respectively. Biological process maintained the most shelf and slope areas as a strong CO2 sink. Overall, despite a small CO2 outgassing area the whole Bering Sea still acted as a net ocean CO2 sink of -6.4 +/- 0.9 mmol m(-2) d(-1) in summer.},
author = {Sun, Heng and Gao, Zhongyong and Qi, Di and shan Chen, Bao and Chen, Liqi and Cai, Wei-Jun},
doi = {10.1016/j.csr.2019.104031},
issn = {02784343},
journal = {Continental Shelf Research},
month = {jan},
pages = {104031},
title = {{Surface seawater partial pressure of CO2 variability and air–sea CO2 fluxes in the Bering Sea in July 2010}},
volume = {193},
year = {2020}
}
@article{Sun2020,
abstract = {Conservation agriculture has been shown to have multiple benefits for soils, crop yield and the environment, and consequently, no-till, the central practice of conservation agriculture, has rapidly expanded. However, studies show that the potential for carbon (C) sequestration in no-till farming sometimes is not realized, let alone the ability to maintain or improve crop yield. Here we present a global analysis of no-till-induced changes of soil C and crop yield based on 260 and 1,970 paired studies; respectively. We show that, relative to local conventional tillage, arid regions can benefit the most from conservation agriculture by achieving a win-win outcome of enhanced C sequestration and increased crop yield. However, more humid regions are more likely to increase SOC only, while some colder regions have yield losses and soil C loss as likely as soil C gains. In addition to site-specific characteristics and management, a careful assessment of the regional climate is needed to determine the potential benefits of adopting conservation agriculture.},
author = {Sun, Wenjuan and Canadell, Josep G. and Yu, Lijun and Yu, Lingfei and Zhang, Wen and Smith, Pete and Fischer, Tony and Huang, Yao},
doi = {10.1111/gcb.15001},
issn = {13652486},
journal = {Global Change Biology},
keywords = {climate,conservation agriculture,crop yield,meta-analysis,soil organic carbon,win-win outcome},
number = {6},
pages = {3325--3335},
pmid = {31953897},
title = {{Climate drives global soil carbon sequestration and crop yield changes under conservation agriculture}},
volume = {26},
year = {2020}
}
@article{Suntharalingam2012,
abstract = {Anthropogenically induced increases in nitrogen deposition to the ocean can stimulate marine productivity and oceanic emission of nitrous oxide. We present the first global ocean model assessment of the impact on marine N2O of increases in nitrogen deposition from the pre‐industrial era to the present. We find significant regional increases in marine N2O production downwind of continental outflow, in coastal and inland seas (15–30{\%}), and nitrogen limited regions of the North Atlantic and North Pacific (5–20{\%}). The largest changes occur in the northern Indian Ocean (up to 50{\%}) resulting from a combination of high deposition fluxes and enhanced N2O production pathways in local hypoxic zones. Oceanic regions relatively unaffected by anthropogenic nitrogen deposition indicate much smaller changes ({\textless}2{\%}). The estimated change in oceanic N2O source on a global scale is modest (0.08–0.34 Tg N yr−1, ∼3–4{\%} of the total ocean source), and consistent with the estimated impact on global export production (∼4{\%}).

},
author = {Suntharalingam, Parvadha and Buitenhuis, Erik and {Le Qu{\'{e}}r{\'{e}}}, Corinne and Dentener, Frank and Nevison, Cynthia and Butler, James H. and Bange, Hermann W. and Forster, Grant},
doi = {10.1029/2011GL050778},
journal = {Geophysical Research Letters},
month = {apr},
number = {7},
pages = {L07605},
publisher = {Wiley-Blackwell},
title = {{Quantifying the impact of anthropogenic nitrogen deposition on oceanic nitrous oxide}},
url = {http://doi.wiley.com/10.1029/2011GL050778},
volume = {39},
year = {2012}
}
@article{Suntharalingam2019,
author = {Suntharalingam, Parvadha and Zamora, Lauren M. and Bange, Hermann W. and Bikkina, Srinivas and Buitenhuis, Erik and Kanakidou, Maria and Lamarque, Jean-Francois and Landolfi, Angela and Resplandy, Laure and Sarin, Manmohan M. and Seitzinger, Sybil and Singh, Arvind},
doi = {10.1016/j.dsr2.2019.03.007},
issn = {09670645},
journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
month = {aug},
pages = {104--113},
title = {{Anthropogenic nitrogen inputs and impacts on oceanic N2O fluxes in the northern Indian Ocean: The need for an integrated observation and modelling approach}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S096706451830198X},
volume = {166},
year = {2019}
}
@article{Sutton2016,
abstract = {Abstract. One of the major challenges to assessing the impact of ocean acidification on marine life is detecting and interpreting long-term change in the context of natural variability. This study addresses this need through a global synthesis of monthly pH and aragonite saturation state ($\Omega$arag) climatologies for 12 open ocean, coastal, and coral reef locations using 3-hourly moored observations of surface seawater partial pressure of CO2 and pH collected together since as early as 2010. Mooring observations suggest open ocean subtropical and subarctic sites experience present-day surface pH and $\Omega$arag conditions outside the bounds of preindustrial variability throughout most, if not all, of the year. In general, coastal mooring sites experience more natural variability and thus, more overlap with preindustrial conditions; however, present-day $\Omega$arag conditions surpass biologically relevant thresholds associated with ocean acidification impacts on Mytilus californianus ($\Omega$arag{\textless}1.8) and Crassostrea gigas ($\Omega$arag{\textless}2.0) larvae in the California Current Ecosystem (CCE) and Mya arenaria larvae in the Gulf of Maine ($\Omega$arag{\textless}1.6). At the most variable mooring locations in coastal systems of the CCE, subseasonal conditions approached $\Omega$arag = 1. Global and regional models and data syntheses of ship-based observations tended to underestimate seasonal variability compared to mooring observations. Efforts such as this to characterize all patterns of pH and $\Omega$arag variability and change at key locations are fundamental to assessing present-day biological impacts of ocean acidification, further improving experimental design to interrogate organism response under real-world conditions, and improving predictive models and vulnerability assessments seeking to quantify the broader impacts of ocean acidification.},
author = {Sutton, Adrienne J. and Sabine, Christopher L. and Feely, Richard A. and Cai, Wei-Jun and Cronin, Meghan F. and McPhaden, Michael J. and Morell, Julio M. and Newton, Jan A. and Noh, Jae-Hoon and {\'{O}}lafsd{\'{o}}ttir, S{\'{o}}lveig R. and Salisbury, Joseph E. and Send, Uwe and Vandemark, Douglas C. and Weller, Robert A.},
doi = {10.5194/bg-13-5065-2016},
issn = {1726-4189},
journal = {Biogeosciences},
month = {sep},
number = {17},
pages = {5065--5083},
title = {{Using present-day observations to detect when anthropogenic change forces surface ocean carbonate chemistry outside preindustrial bounds}},
url = {https://www.biogeosciences.net/13/5065/2016/},
volume = {13},
year = {2016}
}
@article{essd-11-421-2019,
abstract = {Abstract. Ship-based time series, some now approaching over 3 decades long, are critical climate records that have dramatically improved our ability to characterize natural and anthropogenic drivers of ocean carbon dioxide (CO2) uptake and biogeochemical processes. Advancements in autonomous marine carbon sensors and technologies over the last 2 decades have led to the expansion of observations at fixed time series sites, thereby improving the capability of characterizing sub-seasonal variability in the ocean. Here, we present a data product of 40 individual autonomous moored surface ocean pCO2 (partial pressure of CO2) time series established between 2004 and 2013, 17 also include autonomous pH measurements. These time series characterize a wide range of surface ocean carbonate conditions in different oceanic (17 sites), coastal (13 sites), and coral reef (10 sites) regimes. A time of trend emergence (ToE) methodology applied to the time series that exhibit well-constrained daily to interannual variability and an estimate of decadal variability indicates that the length of sustained observations necessary to detect statistically significant anthropogenic trends varies by marine environment. The ToE estimates for seawater pCO2 and pH range from 8 to 15 years at the open ocean sites, 16 to 41 years at the coastal sites, and 9 to 22 years at the coral reef sites. Only two open ocean pCO2 time series, Woods Hole Oceanographic Institution Hawaii Ocean Time-series Station (WHOTS) in the subtropical North Pacific and Stratus in the South Pacific gyre, have been deployed longer than the estimated trend detection time and, for these, deseasoned monthly means show estimated anthropogenic trends of 1.9±0.3 and 1.6±0.3{\&}thinsp;µatm yr−1, respectively. In the future, it is possible that updates to this product will allow for the estimation of anthropogenic trends at more sites; however, the product currently provides a valuable tool in an accessible format for evaluating climatology and natural variability of surface ocean carbonate chemistry in a variety of regions. Data are available at https://doi.org/10.7289/V5DB8043 and https://www.nodc.noaa.gov/ocads/oceans/Moorings/ndp097.html (Sutton et al., 2018). ]]{\textgreater}},
author = {Sutton, Adrienne J and Feely, Richard A and Maenner-Jones, Stacy and Musielwicz, Sylvia and Osborne, John and Dietrich, Colin and Monacci, Natalie and Cross, Jessica and Bott, Randy and Kozyr, Alex and Andersson, Andreas J and Bates, Nicholas R and Cai, Wei-Jun and Cronin, Meghan F and {De Carlo}, Eric H and Hales, Burke and Howden, Stephan D and Lee, Charity M and Manzello, Derek P and McPhaden, Michael J and Mel{\'{e}}ndez, Melissa and Mickett, John B and Newton, Jan A and Noakes, Scott E and Noh, Jae Hoon and Olafsdottir, Solveig R and Salisbury, Joseph E and Send, Uwe and Trull, Thomas W and Vandemark, Douglas C and Weller, Robert A},
doi = {10.5194/essd-11-421-2019},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {mar},
number = {1},
pages = {421--439},
title = {{Autonomous seawater CO2 and pH time series from 40 surface buoys and the emergence of anthropogenic trends}},
url = {https://www.earth-syst-sci-data.net/11/421/2019/},
volume = {11},
year = {2019}
}
@article{Sutton2014,
abstract = {Abstract The equatorial Pacific is a dynamic region that plays an important role in the global carbon cycle. This region is the largest oceanic source of carbon dioxide (CO2) to the atmosphere, which varies interannually dependent on the El Ni{\~{n}}o-Southern Oscillation (ENSO) and other climatic and oceanic drivers. We present high-resolution observations of surface ocean CO2 partial pressure (pCO2) at four fixed locations in the Ni{\~{n}}o 3.4 area with data sets encompassing 10 ENSO warm and cold events from 1997 to 2011. The mooring observations confirm that ENSO controls much of the interannual variability in surface seawater pCO2 with values ranging from 315 to 578 µatm. The mooring time series also capture the temporal variability necessary to make the first estimates of long-term pH trends in the equatorial Pacific, which suggests that the combination of ocean acidification and decadal variability creates conditions for high rates of pH change since the beginning of the mooring record. Anthropogenic CO2 increases play a dominant role in significant observed seawater pCO2 trends of +2.3 to +3.3 µatm yr?1 and pH trends of ?0.0018 to ?0.0026 yr?1 across the full time series in this region. However, increased upwelling driven by increased trade winds, a shallower thermocline, and increased frequency of La Ni{\~{n}}a events also contribute an average of 40{\%} of the observed trends since 1998. These trends are higher than previous estimates based on underway observations and suggest that the equatorial Pacific is contributing a greater amount of CO2 to the atmospheric CO2 inventory over the last decade.},
annote = {doi: 10.1002/2013GB004679},
author = {Sutton, Adrienne J and Feely, Richard A and Sabine, Christopher L and McPhaden, Michael J and Takahashi, Taro and Chavez, Francisco P and Friederich, Gernot E and Mathis, Jeremy T},
doi = {10.1002/2013GB004679},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
keywords = {CO2,ENSO,El Ni{\~{n}}o,climate change,ocean acidification},
month = {feb},
number = {2},
pages = {131--145},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Natural variability and anthropogenic change in equatorial Pacific surface ocean pCO2 and pH}},
url = {https://doi.org/10.1002/2013GB004679},
volume = {28},
year = {2014}
}
@article{Swann2016a,
author = {Swann, Abigail L. S. and Hoffman, Forrest M. and Koven, Charles D. and Randerson, James T.},
doi = {10.1073/pnas.1604581113},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {sep},
number = {36},
pages = {10019--10024},
title = {{Plant responses to increasing CO2 reduce estimates of climate impacts on drought severity}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1604581113},
volume = {113},
year = {2016}
}
@article{Sweeney2016,
abstract = {Continuous measurements of atmospheric methane (CH4) mole fractions measured by NOAA's Global Greenhouse Gas Reference Network in Barrow, AK (BRW), show strong enhancements above background values when winds come from the land sector from July to December from 1986 to 2015, indicating that emissions from arctic tundra continue through autumn and into early winter. Twenty-nine years of measurements show little change in seasonal mean land sector CH4 enhancements, despite an increase in annual mean temperatures of 1.2 ± 0.8°C/decade (2$\sigma$). The record does reveal small increases in CH4 enhancements in November and December after 2010 due to increased late-season emissions. The lack of significant long-term trends suggests that more complex biogeochemical processes are counteracting the observed short-term (monthly) temperature sensitivity of 5.0 ± 3.6 ppb CH4/°C. Our results suggest that even the observed short-term temperature sensitivity from the Arctic will have little impact on the global atmospheric CH4 budget in the long term if future trajectories evolve with the same temperature sensitivity.},
author = {Sweeney, Colm and Dlugokencky, Edward and Miller, Charles E. and Wofsy, Steven and Karion, Anna and Dinardo, Steve and Chang, Rachel Y.W. and Miller, John B. and Bruhwiler, Lori and Crotwell, Andrew M. and Newberger, Tim and McKain, Kathryn and Stone, Robert S. and Wolter, Sonja E. and Lang, Patricia E. and Tans, Pieter},
doi = {10.1002/2016GL069292},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Arctic,climate change,methane,permafrost},
month = {jun},
number = {12},
pages = {6604--6611},
title = {{No significant increase in long-term CH4 emissions on North Slope of Alaska despite significant increase in air temperature}},
url = {http://doi.wiley.com/10.1002/2016GL069292},
volume = {43},
year = {2016}
}
@article{Szulczewski2012a,
abstract = {In carbon capture and storage (CCS), CO 2 is captured at power plants and then injected underground into reservoirs like deep saline aquifers for long-term storage. While CCS may be critical for the continued use of fossil fuels in a carbon-constrained world, the deployment of CCS has been hindered by uncertainty in geologic storage capacities and sustainable injection rates, which has contributed to the absence of concerted government policy. Here, we clarify the potential of CCS to mitigate emissions in the United States by developing a storage-capacity supply curve that, unlike current large-scale capacity estimates, is derived from the fluid mechanics of CO 2 injection and trapping and incorporates injection- rate constraints. We show that storage supply is a dynamic quantity that grows with the duration of CCS, and we interpret the lifetime of CCS as the time for which the storage supply curve exceeds the storage demand curve from CO2 production. We show that in the United States, if CO2 production from power generation continues to rise at recent rates, then CCS can store enough CO 2 to stabilize emissions at current levels for at least 100 y. This result suggests that the large-scale implementation of CCS is a geologically viable climate-change mitigation option in the United States over the next century.},
author = {Szulczewski, Michael L. and MacMinn, Christopher W. and Herzog, Howard J. and Juanes, Ruben},
doi = {10.1073/pnas.1115347109},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {apr},
number = {14},
pages = {5185--5189},
title = {{Lifetime of carbon capture and storage as a climate-change mitigation technology}},
url = {http://www.pnas.org/cgi/doi/10.1073/pnas.1115347109},
volume = {109},
year = {2012}
}
@article{Tachiiri2015,
abstract = {We analyzed a dataset from an experiment of an earth system model of intermediate complexity,$\backslash$nfocusing on the change in transient climate response to cumulative carbon emissions (TCRE) after$\backslash$natmospheric CO 2 concentration was stabilized in the Representative Concentration Pathway (RCP) 4.5.$\backslash$nWe estimated the TCRE in 2005 at 0.3–2.4 K/TtC for an unconstrained case and 1.1–1.7 K/TtC when$\backslash$nconstrained with historical and present-day observational data, the latter result being consistent$\backslash$nwith other studies. The range of TCRE increased when the increase of CO 2 concentration was$\backslash$nmoderated and then stabilized. This is because the larger (smaller) TCRE members yield even greater$\backslash$n(less) TCRE. An additional experiment to assess the equilibrium state revealed significant changes$\backslash$nin temperature and cumulative carbon emissions after 2300. We also found that variation of land$\backslash$ncarbon uptake is significant to the total allowable carbon emissions and subsequent change of the$\backslash$nTCRE. Additionally, in our experiment, we revealed that equilibrium climate sensitivity (ECS), one$\backslash$nof the 12 parameters perturbed in the ensemble experiment, has a strong positive relationship with$\backslash$nthe TCRE at the beginning of the stabilization and its subsequent change. We confirmed that for$\backslash$nparticipant models in the Coupled Model Intercomparison Project Phase 5, ECS has a strong positive$\backslash$nrelationship with TCRE. For models using similar experimental settings, there is a positive$\backslash$nrelationship with TCRE for the start of the period of stabilization in CO 2 concentration, and rate$\backslash$nof change after stabilization. The results of this study are influential regarding the total$\backslash$nallowable carbon emissions calculated from the TCRE and the temperature increase set as the$\backslash$nmitigation target.},
author = {Tachiiri, Kaoru and Hajima, Tomohiro and Kawamiya, Michio},
doi = {10.1088/1748-9326/10/12/125018},
issn = {1748-9326},
journal = {Environmental Research Letters},
keywords = {RCP4.5,earth system model of intermediate complexity,equilibrium climate sensitivity,land carbon cycle,transient climate response to cumulative carbon em,uncertainty},
month = {dec},
number = {12},
pages = {125018},
publisher = {IOP Publishing},
title = {{Increase of uncertainty in transient climate response to cumulative carbon emissions after stabilization of atmospheric CO2 concentration}},
url = {http://stacks.iop.org/1748-9326/10/i=12/a=125018?key=crossref.ad6b2e4260fcf4387247a5bd896565ef},
volume = {10},
year = {2015}
}
@article{Tachiiri2019,
abstract = {Near-constancy of the transient climate response to cumulative carbon emissions (TCRE) facilitates the development of future emission pathways compatible with temperature targets. However, most studies have explored TCRE under scenarios of temperature increase. We used an Earth system model (MIROC-ESM) to examine TCRE in scenarios with increasing and stable CO 2 concentrations, as well as overshoot pathways in which global mean temperatures peak and decline. Results showed that TCRE is stable under scenarios of increasing or stable CO 2 concentration at an atmospheric CO 2 concentration ( p CO 2 ) double the pre-industrial level. However, in the case of overshoot pathways and a stable p CO 2 scenario at a quadrupled p CO 2 level, the TCRE increases by 10{\%}–50{\%}, with large increases over a short period just after p CO 2 starts to decrease. During the period of p CO 2 increase, annual ocean heat uptake (OHU) and ocean carbon storage (C O ) (or cumulative ocean carbon uptake from the start of the experiment) exhibit similar changes, resulting in a stable TCRE. During the p CO 2 decrease period, after a sudden TCRE increase when p CO 2 starts to decrease, the OHU decreases and C O increases (relative to the p CO 2 increase period) balance each other out, resulting in a stable TCRE. In overshoot pathways, the temperature distribution when the global mean temperature anomaly cools to 1.5 °C reveals small warming over land and large warming over the oceans relative to the 1{\%} per annum pCO 2 increasing scenario, particularly in some high-latitude areas of both hemispheres. The increase in TCRE with overshoot pathways decreases the carbon budget for the temperature anomaly targets in such scenarios. Our analysis showed a 16{\%}–35{\%} decrease in the remaining carbon budget for the 1.5 °C global warming target, in comparison with the reference scenario with a 1{\%} per year p CO 2 increase, for pathways peaking at the doubled p CO 2 level followed by decline to the pre-industrial level.},
author = {Tachiiri, Kaoru and Hajima, Tomohiro and Kawamiya, Michio},
doi = {10.1088/1748-9326/ab57d3},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {dec},
number = {12},
pages = {124067},
title = {{Increase of the transient climate response to cumulative carbon emissions with decreasing CO2 concentration scenarios}},
url = {http://iopscience.iop.org/article/10.1088/1748-9326/ab57d3},
volume = {14},
year = {2019}
}
@article{Tagesson2020a,
abstract = {Anthropogenic land use and land cover changes (LULCC) have a large impact on the global terrestrial carbon sink, but this effect is not well characterized according to biogeographical region. Here, using state-of-the-art Earth observation data and a dynamic global vegetation model, we estimate the impact of LULCC on the contribution of biomes to the terrestrial carbon sink between 1992 and 2015. Tropical and boreal forests contributed equally, and with the largest share of the mean global terrestrial carbon sink. CO2 fertilization was found to be the main driver increasing the terrestrial carbon sink from 1992 to 2015, but the net effect of all drivers (CO2 fertilization and nitrogen deposition, LULCC and meteorological forcing) caused a reduction and an increase, respectively, in the terrestrial carbon sink for tropical and boreal forests. These diverging trends were not observed when applying a conventional LULCC dataset, but were also evident in satellite passive microwave estimates of aboveground biomass. These datasets thereby converge on the conclusion that LULCC have had a greater impact on tropical forests than previously estimated, causing an increase and decrease of the contributions of boreal and tropical forests, respectively, to the growing terrestrial carbon sink.},
author = {Tagesson, Torbern and Schurgers, Guy and Horion, St{\'{e}}phanie and Ciais, Philippe and Tian, Feng and Brandt, Martin and Ahlstr{\"{o}}m, Anders and Wigneron, Jean-Pierre and Ard{\"{o}}, Jonas and Olin, Stefan and Fan, Lei and Wu, Zhendong and Fensholt, Rasmus},
doi = {10.1038/s41559-019-1090-0},
issn = {2397-334X},
journal = {Nature Ecology {\&} Evolution},
month = {feb},
number = {2},
pages = {202--209},
title = {{Recent divergence in the contributions of tropical and boreal forests to the terrestrial carbon sink}},
url = {http://www.nature.com/articles/s41559-019-1090-0},
volume = {4},
year = {2020}
}
@article{Taillardat2018,
author = {Taillardat, Pierre and Friess, Daniel A. and Lupascu, Massimo},
doi = {10.1098/rsbl.2018.0251},
issn = {1744-9561},
journal = {Biology Letters},
month = {oct},
number = {10},
pages = {20180251},
title = {{Mangrove blue carbon strategies for climate change mitigation are most effective at the national scale}},
url = {https://royalsocietypublishing.org/doi/10.1098/rsbl.2018.0251},
volume = {14},
year = {2018}
}
@article{Takahashi2014,
author = {Takahashi, Taro and Sutherland, S.C. and Chipman, D.W. and Goddard, J.G. and Ho, Cheng and Newberger, Timothy and Sweeney, Colm and Munro, D.R.},
doi = {10.1016/j.marchem.2014.06.004},
issn = {03044203},
journal = {Marine Chemistry},
keywords = {Carbonate chemistry,Climatology,Global ocean,Seasonal and decadal change,Surface water,pH},
month = {aug},
pages = {95--125},
title = {{Climatological distributions of pH, pCO2, total CO2, alkalinity, and CaCO3 saturation in the global surface ocean, and temporal changes at selected locations}},
url = {http://www.sciencedirect.com/science/article/pii/S0304420314001042 https://linkinghub.elsevier.com/retrieve/pii/S0304420314001042},
volume = {164},
year = {2014}
}
@article{Takata2017,
abstract = {Carbon dioxide (CO2) fluxes by different methods vary largely at global, regional and local scales. The net CO2fluxes by three bottom-up methods (tower observation (TWR), biogeochemical models (GTM), and a data-driven model (SVR)), and an ensemble of atmospheric inversions (top-down method, INV) are compared in Yakutsk, Siberia for 2004-2013. The region is characterized by highly homogeneous larch forest on a flat terrain. The ecosystem around Yakutsk shows a net sink of CO2by all the methods (means during 2004-2007 were 10.9 g C m-2month-1by TWR, 4.28 g C m-2month-1by GTM, 5.62 g C m-2month-1and 0.863 g C m-2month-1by SVR at two different scales, and 4.89 g C m-2month-1by INV). Absorption in summer (June-August) was smaller by three bottom-up methods (ranged from 88.1 to 191.8 g C m-2month-1) than the top-down method (223.6 g C m-2month-1). Thus the peak-to-trough amplitude of the seasonal cycle is greater for the inverse models than bottom-up methods. The monthly-mean seasonal cycles agree among the four methods within the range of inter-model variations. The interannual variability estimated by an ensemble of inverse models and a site-scale data-driven model (the max-min range was 35.8 g C m-2month-1and 34.2 g C m-2month-1) is more similar to that of the tower observation (42.4 g C m-2month-1) than those by the biogeochemical models and the large-scale data-driven model (9.5 g C m-2month-1and 1.45 g C m-2month-1). The inverse models and tower observations captured a reduction in CO2uptake after 2008 due to unusual waterlogging.},
author = {Takata, K. and Patra, P.K. and Kotani, A. and Mori, J. and Belikov, D. and Ichii, K. and Saeki, T. and Ohta, T. and Saito, K. and Ueyama, M. and Ito, A. and Maksyutov, S. and Miyazaki, S. and Burke, E.J. and Ganshin, A. and Iijima, Y. and Ise, T. and Machiya, H. and Maximov, T.C. and Niwa, Y. and O'Ishi, R. and Park, H. and Sasai, T. and Sato, H. and Tei, S. and Zhuravlev, R. and Machida, T. and Sugimoto, A. and Aoki, S.},
doi = {10.1088/1748-9326/aa926d},
issn = {17489326},
journal = {Environmental Research Letters},
number = {12},
pages = {125012},
title = {{Reconciliation of top-down and bottom-up CO2 fluxes in Siberian larch forest}},
volume = {12},
year = {2017}
}
@article{Takatani2012,
abstract = {The Japan Meteorological Agency has acquired dissolved oxygen (DO) concentration data each year since 1967 along the 137°E repeat section in the western North Pacific. In this data set we found significant regional temporal trends of decreasing or increasing DO concentrations on various isopycnal surfaces. DO decreases were particularly significant after the mid-1980s in the subtropical gyre; mean rates of DO change at 20?25°N for 1985?2010 were ?0.28 ± 0.08 ?mol kg?1 yr?1 on 25.5 $\sigma$? in North Pacific Subtropical Mode Water (NPSTMW), ?0.36 ± 0.08 ?mol kg?1 yr?1 on 26.8 $\sigma$? in North Pacific Intermediate Water (NPIW), and ?0.23 ± 0.04 ?mol kg?1 yr?1 on 27.3 $\sigma$? in the O2 minimum Layer (OML). The cause of DO decrease differed among isopycnal surfaces. On density surfaces shallower than 26.0 $\sigma$? (less than about 400 m), the deepening of isopycnal surfaces and decline of oxygen solubility due to ocean warming have had the greatest influence. In particular, between 25.2 $\sigma$? and 25.8 $\sigma$? near the NPSTMW their combined contributions accounted for {\textgreater}50{\%} of the DO decrease. In the NPIW core at roughly 26.8 $\sigma$? (?700 m), the decline in DO was attributable to the DO decrease in the formation region. In the OML between 27.0 $\sigma$? and 27.3 $\sigma$? (?1000 m), the DO decrease likely resulted from an increase in westward transport of low O2 water due to strengthening of the subtropical gyre. The result of this study shows the importance of the long-term and high-frequency along the 137°E repeat section.},
annote = {doi: 10.1029/2011GB004227},
author = {Takatani, Yusuke and Sasano, Daisuke and Nakano, Toshiya and Midorikawa, Takashi and Ishii, Masao},
doi = {10.1029/2011GB004227},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {jun},
number = {2},
pages = {GB2013},
publisher = {Wiley-Blackwell},
title = {{Decrease of dissolved oxygen after the mid-1980s in the western North Pacific subtropical gyre along the 137°E repeat section}},
url = {https://doi.org/10.1029/2011GB004227 http://doi.wiley.com/10.1029/2011GB004227},
volume = {26},
year = {2012}
}
@article{Takeshita2015a,
abstract = {Abstract. Assessing the impacts of anthropogenic ocean acidification requires knowledge of present-day and future environmental conditions. Here, we present a simple model for upwelling margins that projects anthropogenic acidification trajectories by combining high-temporal-resolution sensor data, hydrographic surveys for source water characterization, empirical relationships of the CO2 system, and the atmospheric CO2 record. This model characterizes CO2 variability on timescales ranging from hours (e.g., tidal) to months (e.g., seasonal), bridging a critical knowledge gap in ocean acidification research. The amount of anthropogenic carbon in a given water mass is dependent on the age; therefore a density–age relationship was derived for the study region and then combined with the 2013 Intergovernmental Panel on Climate Change CO2 emission scenarios to add density-dependent anthropogenic carbon to the sensor time series. The model was applied to time series from autonomous pH sensors deployed in the surf zone, kelp forest, submarine canyon edge, and shelf break in the upper 100 m of the Southern California Bight. All habitats were within 5 km of one another, and exhibited unique, habitat-specific CO2 variability signatures and acidification trajectories, demonstrating the importance of making projections in the context of habitat-specific CO2 signatures. In general, both the mean and range of pCO2 increase in the future, with the greatest increase in both magnitude and range occurring in the deeper habitats due to reduced buffering capacity. On the other hand, the saturation state of aragonite ({\&}Omega;Ar) decreased in both magnitude and range. This approach can be applied to the entire California Current System, and upwelling margins in general, where sensor and complementary hydrographic data are available.},
author = {Takeshita, Y. and Frieder, C. A. and Martz, T. R. and Ballard, J. R. and Feely, R. A. and Kram, S. and Nam, S. and Navarro, M. O. and Price, N. N. and Smith, J. E.},
doi = {10.5194/bg-12-5853-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {19},
pages = {5853--5870},
title = {{Including high-frequency variability in coastal ocean acidification projections}},
url = {https://www.biogeosciences.net/12/5853/2015/},
volume = {12},
year = {2015}
}
@article{Talhelm2014a,
author = {Talhelm, Alan F. and Pregitzer, Kurt S. and Kubiske, Mark E. and Zak, Donald R. and Campany, Courtney E. and Burton, Andrew J. and Dickson, Richard E. and Hendrey, George R. and Isebrands, J. G. and Lewin, Keith F. and Nagy, John and Karnosky, David F.},
doi = {10.1111/gcb.12564},
issn = {1354-1013},
journal = {Global Change Biology},
month = {aug},
number = {8},
pages = {2492--2504},
title = {{Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests}},
volume = {20},
year = {2014}
}
@article{Talley2016,
abstract = {Global ship-based programs, with highly accurate, full water column physical and biogeochemical observations repeated decadally since the 1970s, provide a crucial resource for documenting ocean change. The ocean, a central component of Earth's climate system, is taking up most of Earth's excess anthropogenic heat, with about 19{\%} of this excess in the abyssal ocean beneath 2,000 m, dominated by Southern Ocean warming. The ocean also has taken up about 27{\%} of anthropogenic carbon, resulting in acidification of the upper ocean. Increased stratification has resulted in a decline in oxygen and increase in nutrients in the Northern Hemisphere thermocline and an expansion of tropical oxygen minimum zones. Southern Hemisphere thermocline oxygen increased in the 2000s owing to stronger wind forcingand ventilation. The most recent decade of global hydrography has mapped dissolved organic carbon, a large, bioactive reservoir, for the first time and quantified its contribution to export production (?20{\%}) and deep-ocean oxygen utilization. Ship-based measurements also show that vertical diffusivity increases from a minimum in the thermocline to a maximum within the bottom 1,500 m, shifting our physical paradigm of the ocean's overturning circulation.},
annote = {doi: 10.1146/annurev-marine-052915-100829},
author = {Talley, L.D. and Feely, R.A. and Sloyan, B.M. and Wanninkhof, R and Baringer, M.O. and Bullister, J.L. and Carlson, C.A. and Doney, S.C. and Fine, R.A. and Firing, E and Gruber, N and Hansell, D.A. and Ishii, M and Johnson, G.C. and Katsumata, K and Key, R.M. and Kramp, M and Langdon, C and Macdonald, A.M. and Mathis, J.T. and McDonagh, E.L. and Mecking, S and Millero, F.J. and Mordy, C.W. and Nakano, T and Sabine, C.L. and Smethie, W.M. and Swift, J.H. and Tanhua, T and Thurnherr, A.M. and Warner, M.J. and Zhang, J.-Z.},
doi = {10.1146/annurev-marine-052915-100829},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {185--215},
publisher = {Annual Reviews},
title = {{Changes in Ocean Heat, Carbon Content, and Ventilation: A Review of the First Decade of GO-SHIP Global Repeat Hydrography}},
url = {https://doi.org/10.1146/annurev-marine-052915-100829 http://www.annualreviews.org/doi/10.1146/annurev-marine-052915-100829},
volume = {8},
year = {2016}
}
@article{Tan2015,
abstract = {Methane is the second most powerful carbon-based greenhouse gas in the atmosphere and its production in the natural environment through methanogenesis is positively correlated with temperature. Recent field studies showed that methane emissions from Arctic thermokarst lakes are significant and could increase by two- to four-fold due to global warming. But the estimates of this source are still poorly constrained. By using a process-based climate-sensitive lake biogeochemical model, we estimated that the total amount of methane emissions from Arctic lakes is 11.86 Tg yr −1 , which is in the range of recent estimates of 7.1–17.3 Tg yr −1 and is on the same order of methane emissions from northern high-latitude wetlands. The methane emission rate varies spatially over high latitudes from 110.8 mg CH 4 m −2 day −1 in Alaska to 12.7 mg CH 4 m −2 day −1 in northern Europe. Under Representative Concentration Pathways (RCP) 2.6 and 8.5 future climate scenarios, methane emissions from Arctic lakes will increase by 10.3 and 16.2 Tg CH 4 yr −1 , respectively, by the end of the 21st century.},
author = {Tan, Zeli and Zhuang, Qianlai},
doi = {10.1088/1748-9326/10/5/054016},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {may},
number = {5},
pages = {054016},
title = {{Arctic lakes are continuous methane sources to the atmosphere under warming conditions}},
url = {http://stacks.iop.org/1748-9326/10/i=5/a=054016 http://stacks.iop.org/1748-9326/10/i=5/a=054016?key=crossref.13b357e970ac45396bd7b5e2d08a658f},
volume = {10},
year = {2015}
}
@article{Tan2017,
author = {Tan, Zheng-Hong and Zeng, Jiye and Zhang, Yong-Jiang and Slot, Martijn and Gamo, Minoru and Hirano, Takashi and Kosugi, Yoshiko and da Rocha, Humberto R and Saleska, Scott R and Goulden, Michael L and Wofsy, Steven C and Miller, Scott D and Manzi, Antonio O and Nobre, Antonio D and de Camargo, Plinio B and Restrepo-Coupe, Natalia},
doi = {10.1088/1748-9326/aa6f97},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {may},
number = {5},
pages = {054022},
publisher = {IOP Publishing},
title = {{Optimum air temperature for tropical forest photosynthesis: mechanisms involved and implications for climate warming}},
url = {http://dx.doi.org/10.1088/1748-9326/aa6f97 http://stacks.iop.org/1748-9326/12/i=5/a=054022?key=crossref.018a465cb8b40c41385e05888d65e238},
volume = {12},
year = {2017}
}
@article{Tanhua2017,
abstract = {The Southern Ocean is the most important area of anthropogenic carbon (Cant) uptake in the world ocean, only rivalled in importance by the North Atlantic Ocean. Significant variability on decadal time-scales in the uptake of Cant in the Southern Ocean has been observed and modelled, likely with consequences for the interior ocean storage of Cant in the region, and implications for the global carbon budget. Here we use eight cruises between 1973 and 2012 to assess decadal variability in Cant storage rates in the southeast Atlantic sector of the Southern Ocean. For this we employed the extended multiple linear regression (eMLR) method. We relate variability in DIC (dissolved inorganic carbon) storage, which is assumed to equal anthropogenic carbon storage, to changes in ventilation as observed from repeat measurements of transient tracers. Within the Antarctic Intermediate Water (AAIW) layer, which is the dominant transport conduit for Cant into the interior ocean, moderate Cant storage rates were found without any clear temporal trend. In Subantarctic Mode Water (SAMW), a less dense water mass found north of the Subantarctic Front and above AAIW, high storage rates of Cant were observed up to about 2005 but lower rates in more recent times. The transient tracer data suggest a significant speed-up of ventilation in the summer warmed upper part of AAIW between 1998 and 2012, which is consistent with the high storage rate of Cant. A shift of more northern Cant storage to more southern storage in near surface waters was detected in the early 2000s. Beneath the AAIW the eMLR method as applied here did not detect significant storage of Cant. However, the presence of the transient tracer CFC-12 all through the water column suggests that some Cant should be present, but at concentrations not reliably quantifiable. The observed temporal variability in the interior ocean seems at a first glance to be out of phase with observed surface ocean Cant fluxes, but this can be explained by the time delay for the surface ocean signal to manifest itself in the interior of the ocean.},
author = {Tanhua, Toste and Hoppema, Mario and Jones, Elizabeth M. and St{\"{o}}ven, Tim and Hauck, Judith and D{\'{a}}vila, Melchor Gonz{\'{a}}lez and Santana-Casiano, Magdalena and {\'{A}}lvarez, Marta and Strass, Volker H.},
doi = {10.1016/j.dsr2.2016.10.004},
issn = {09670645},
journal = {Deep Sea Research Part II: Topical Studies in Oceanography},
month = {apr},
pages = {26--38},
publisher = {Pergamon},
title = {{Temporal changes in ventilation and the carbonate system in the Atlantic sector of the Southern Ocean}},
url = {https://www.sciencedirect.com/science/article/pii/S0967064516303046?via{\%}3Dihub https://linkinghub.elsevier.com/retrieve/pii/S0967064516303046},
volume = {138},
year = {2017}
}
@article{ISI:000286517100005,
abstract = {A global Earth System model is employed to investigate the role of direct temperature effects in the response of marine ecosystems to climate change. While model configurations with and without consideration of explicit temperature effects can reproduce observed current biogeochemical tracer distributions and estimated carbon export about equally well, carbon flow through the model ecosystem reveals strong temperature sensitivities. Depending on whether biological processes are assumed temperature sensitive or not, simulated marine net primary production (NPP) increases or decreases under projected climate change driven by a business-as-usual CO2 emission scenario for the 21st century. This suggests that indirect temperature effects such as changes in the supply of nutrients and light are not the only relevant factors to be considered when modeling the response of marine ecosystems to climate change. A better understanding of direct temperature effects on marine ecosystems is required before even the direction of change in NPP can be reliably predicted. Citation: Taucher, J., and A. Oschlies (2011), Can we predict the direction of marine primary production change under global warming?, Geophys. Res. Lett., 38, L02603, doi: 10.1029/2010GL045934.},
author = {Taucher, J and Oschlies, A},
doi = {10.1029/2010GL045934},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {jan},
number = {2},
pages = {L02603},
title = {{Can we predict the direction of marine primary production change under global warming?}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2010GL045934 http://doi.wiley.com/10.1029/2010GL045934},
volume = {38},
year = {2011}
}
@article{Taucher2021,
author = {Taucher, Jan and Boxhammer, Tim and Bach, Lennart T. and Paul, Allanah J. and Schartau, Markus and Stange, Paul and Riebesell, Ulf},
doi = {10.1038/s41558-020-00915-5},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jan},
number = {1},
pages = {52--57},
title = {{Changing carbon-to-nitrogen ratios of organic-matter export under ocean acidification}},
url = {http://www.nature.com/articles/s41558-020-00915-5},
volume = {11},
year = {2021}
}
@article{Taylor2012a,
author = {Taylor, Karl E. and Stouffer, Ronald J. and Meehl, Gerald A.},
doi = {10.1175/BAMS-D-11-00094.1},
issn = {0003-0007},
journal = {Bulletin of the American Meteorological Society},
month = {apr},
number = {4},
pages = {485--498},
title = {{An Overview of CMIP5 and the Experiment Design}},
volume = {93},
year = {2012}
}
@article{Tebaldi2007a,
author = {Tebaldi, Claudia and Knutti, Reto},
doi = {10.1098/rsta.2007.2076},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {aug},
number = {1857},
pages = {2053--2075},
title = {{The use of the multi-model ensemble in probabilistic climate projections}},
volume = {365},
year = {2007}
}
@article{bg-16-3883-2019,
author = {Teckentrup, L and Harrison, S P and Hantson, S and Heil, A and Melton, J R and Forrest, M and Li, F and Yue, C and Arneth, A and Hickler, T and Sitch, S and Lasslop, G},
doi = {10.5194/bg-16-3883-2019},
journal = {Biogeosciences},
number = {19},
pages = {3883--3910},
title = {{Response of simulated burned area to historical changes in environmental and anthropogenic factors: a comparison of seven fire models}},
url = {https://www.biogeosciences.net/16/3883/2019/},
volume = {16},
year = {2019}
}
@article{Terhaar2019,
abstract = {The Arctic Ocean, more than any other ocean, is influenced by riverine input of carbon and nutrients. That riverine delivery is likely to change with climate change as runoff increases, permafrost thaws, and tree lines advance. But it is unknown to what extent these changes in riverine delivery will affect Arctic Ocean primary production, air-to-sea CO2 fluxes, and acidification. To test their sensitivity to changing riverine delivery, we made sensitivity tests using an ocean circulation model coupled to an ocean biogeochemical model. In separate idealized simulations, riverine inputs of dissolved inorganic carbon (CT), dissolved organic carbon (DOC), and nutrients were increased by 1{\%}/year until doubling. Doubling riverine nutrient delivery increased primary production by 11{\%} on average across the Arctic basin and by up to 34–35{\%} locally. Doubling riverine DOC delivery resulted in 90{\%} of that added carbon being lost to the atmosphere, partly because it was imposed that once delivered to the ocean, the riverine DOC is instantaneously remineralized to CT. That additional outgassing, when considered alone, reduced the net ingassing of natural CO2 into the Arctic Ocean by 25{\%} while converting the Siberian shelf seas and the Beaufort Sea from net sinks to net sources of carbon to the atmosphere. The remaining 10{\%} of DOC remained in the Arctic Ocean, but having been converted to CT, it enhanced acidification. Conversely, doubling riverine CT increased the Arctic Ocean's average surface pH by 0.02 because riverine total alkalinity delivery increased at the same rate as riverine CT delivery.},
author = {Terhaar, J and Orr, J C and Eth{\'{e}}, C and Regnier, P and Bopp, L},
doi = {https://doi.org/10.1029/2019GB006200},
journal = {Global Biogeochemical Cycles},
keywords = {Arctic Ocean,biogeochemistry,carbon,nutrients,riverine delivery,sensitivity},
number = {8},
pages = {1048--1070},
title = {{Simulated Arctic Ocean Response to Doubling of Riverine Carbon and Nutrient Delivery}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GB006200},
volume = {33},
year = {2019}
}
@article{Terrer2016,
abstract = {Plants buffer increasing atmospheric carbon dioxide (CO 2 ) concentrations through enhanced growth, but the question whether nitrogen availability constrains the magnitude of this ecosystem service remains unresolved. Synthesizing experiments from around the world, we show that CO 2 fertilization is best explained by a simple interaction between nitrogen availability and mycorrhizal association. Plant species that associate with ectomycorrhizal fungi show a strong biomass increase (30 ± 3{\%}, P {\textless} 0.001) in response to elevated CO 2 regardless of nitrogen availability, whereas low nitrogen availability limits CO 2 fertilization (0 ± 5{\%}, P = 0.946) in plants that associate with arbuscular mycorrhizal fungi. The incorporation of mycorrhizae in global carbon cycle models is feasible, and crucial if we are to accurately project ecosystem responses and feedbacks to climate change.},
archivePrefix = {arXiv},
arxivId = {arXiv:1011.1669v3},
author = {Terrer, C{\'{e}}sar and Vicca, Sara and Hungate, Bruce A. and Phillips, Richard P. and Prentice, I Colin},
doi = {10.1126/science.aaf4610},
eprint = {arXiv:1011.1669v3},
isbn = {0196-2892 VO - 42},
issn = {0036-8075},
journal = {Science},
month = {jul},
number = {6294},
pages = {72--74},
pmid = {27365447},
title = {{Mycorrhizal association as a primary control of the CO2 fertilization effect}},
url = {http://www.sciencemag.org/lookup/doi/10.1126/science.aaf4610},
volume = {353},
year = {2016}
}
@article{Terrer2017,
abstract = {Land ecosystems sequester on average about a quarter of anthropogenic CO2 emissions. It has been proposed that nitrogen (N) availability will exert an increasingly limiting effect on plants' ability to store additional carbon (C) under rising CO2, but these mechanisms are not well understood. Here, we review findings from elevated CO2 experiments using a plant economics framework, highlighting how ecosystem responses to elevated CO2 may depend on the costs and benefits of plant interactions with mycorrhizal fungi and symbiotic N‐fixing microbes. We found that N‐acquisition efficiency is positively correlated with leaf‐level photosynthetic capacity and plant growth, and negatively with soil C storage. Plants that associate with ectomycorrhizal fungi and N‐fixers may acquire N at a lower cost than plants associated with arbuscular mycorrhizal fungi. However, the additional growth in ectomycorrhizal plants is partly offset by decreases in soil C pools via priming. Collectively, our results indicate that predictive models aimed at quantifying C cycle feedbacks to global change may be improved by treating N as a resource that can be acquired by plants in exchange for energy, with different costs depending on plant interactions with microbial symbionts.},
author = {Terrer, C{\'{e}}sar and Vicca, Sara and Stocker, Benjamin D. and Hungate, Bruce A. and Phillips, Richard P. and Reich, Peter B. and Finzi, Adrien C. and Prentice, I. Colin},
doi = {10.1111/nph.14872},
isbn = {7476820487},
issn = {0028646X},
journal = {New Phytologist},
month = {jan},
number = {2},
pages = {507--522},
pmid = {29105765},
title = {{Ecosystem responses to elevated CO2 governed by plant–soil interactions and the cost of nitrogen acquisition}},
url = {http://doi.wiley.com/10.1111/nph.14872},
volume = {217},
year = {2018}
}
@article{Terrer2019,
author = {Terrer, C{\'{e}}sar and Jackson, Robert B. and Prentice, I. Colin and Keenan, Trevor F. and Kaiser, Christina and Vicca, Sara and Fisher, Joshua B. and Reich, Peter B. and Stocker, Benjamin D. and Hungate, Bruce A. and Pe{\~{n}}uelas, Josep and McCallum, Ian and Soudzilovskaia, Nadejda A. and Cernusak, Lucas A. and Talhelm, Alan F. and {Van Sundert}, Kevin and Piao, Shilong and Newton, Paul C. D. and Hovenden, Mark J. and Blumenthal, Dana M. and Liu, Yi Y. and M{\"{u}}ller, Christoph and Winter, Klaus and Field, Christopher B. and Viechtbauer, Wolfgang and {Van Lissa}, Caspar J. and Hoosbeek, Marcel R. and Watanabe, Makoto and Koike, Takayoshi and Leshyk, Victor O. and Polley, H. Wayne and Franklin, Oskar},
doi = {10.1038/s41558-019-0545-2},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {sep},
number = {9},
pages = {684--689},
title = {{Nitrogen and phosphorus constrain the CO2 fertilization of global plant biomass}},
url = {http://www.nature.com/articles/s41558-019-0545-2},
volume = {9},
year = {2019}
}
@article{Teuling2019,
abstract = {Abstract. Since the 1950s, Europe has undergone large shifts in climate and land cover. Previous assessments of past and future changes in evapotranspiration or streamflow have either focussed on land use/cover or climate contributions or on individual catchments under specific climate conditions, but not on all aspects at larger scales. Here, we aim to understand how decadal changes in climate (e.g. precipitation, temperature) and land use (e.g. deforestation/afforestation, urbanization) have impacted the amount and distribution of water resource availability (both evapotranspiration and streamflow) across Europe since the 1950s. To this end, we simulate the distribution of average evapotranspiration and streamflow at high resolution (1 km2) by combining (a) a steady-state Budyko model for water balance partitioning constrained by long-term (lysimeter) observations across different land use types, (b) a novel decadal high-resolution historical land use reconstruction, and (c) gridded observations of key meteorological variables. The continental-scale patterns in the simulations agree well with coarser-scale observation-based estimates of evapotranspiration and also with observed changes in streamflow from small basins across Europe. We find that strong shifts in the continental-scale patterns of evapotranspiration and streamflow have occurred between the period around 1960 and 2010. In much of central-western Europe, our results show an increase in evapotranspiration of the order of 5 {\%}–15 {\%} between 1955–1965 and 2005–2015, whereas much of the Scandinavian peninsula shows increases exceeding 15 {\%}. The Iberian Peninsula and other parts of the Mediterranean show a decrease of the order of 5 {\%}–15 {\%}. A similar north–south gradient was found for changes in streamflow, although changes in central-western Europe were generally small. Strong decreases and increases exceeding 45 {\%} were found in parts of the Iberian and Scandinavian peninsulas, respectively. In Sweden, for example, increased precipitation is a larger driver than large-scale reforestation and afforestation, leading to increases in both streamflow and evapotranspiration. In most of the Mediterranean, decreased precipitation combines with increased forest cover and potential evapotranspiration to reduce streamflow. In spite of considerable local- and regional-scale complexity, the response of net actual evapotranspiration to changes in land use, precipitation, and potential evaporation is remarkably uniform across Europe, increasing by ∼ 35–60 km3 yr−1, equivalent to the discharge of a large river. For streamflow, effects of changes in precipitation (∼ 95 km3 yr−1) dominate land use and potential evapotranspiration contributions (∼ 45–60 km3 yr−1). Locally, increased forest cover, forest stand age, and urbanization have led to significant decreases and increases in available streamflow, even in catchments that are considered to be near-natural.},
author = {Teuling, Adriaan J. and de Badts, Emile A. G. and Jansen, Femke A. and Fuchs, Richard and Buitink, Joost and {Hoek van Dijke}, Anne J. and Sterling, Shannon M.},
doi = {10.5194/hess-23-3631-2019},
issn = {1607-7938},
journal = {Hydrology and Earth System Sciences},
month = {sep},
number = {9},
pages = {3631--3652},
title = {{Climate change, reforestation/afforestation, and urbanization impacts on evapotranspiration and streamflow in Europe}},
url = {https://hess.copernicus.org/articles/23/3631/2019/},
volume = {23},
year = {2019}
}
@article{Teuling2017,
author = {Teuling, Adriaan J. and Taylor, Christopher M. and Meirink, Jan Fokke and Melsen, Lieke A. and Miralles, Diego G. and van Heerwaarden, Chiel C. and Vautard, Robert and Stegehuis, Annemiek I. and Nabuurs, Gert-Jan and de Arellano, Jordi Vil{\`{a}}-Guerau},
doi = {10.1038/ncomms14065},
issn = {2041-1723},
journal = {Nature Communications},
month = {apr},
number = {1},
pages = {14065},
title = {{Observational evidence for cloud cover enhancement over western European forests}},
url = {http://www.nature.com/articles/ncomms14065},
volume = {8},
year = {2017}
}
@article{Thomas2015,
abstract = {The representation of the nitrogen (N) cycle in Earth system models (ESMs) is strongly motivated by the constraint N poses on the sequestration of anthropogenic carbon (C). Models typically implement a stoichiometric relationship between C and N in which external supply and assimilation by organisms are adjusted to maintain their internal stoichiometry. N limitation of primary productivity thus occurs if the N supply from uptake and fixation cannot keep up with the construction of tissues allowed by C assimilation. This basic approach, however, presents considerable challenges in how to faithfully represent N limitation. Here, we review how N limitation is currently implemented and evaluated in ESMs and highlight challenges and opportunities in their future development. At or near steady state, N limitation is governed by the magnitude of losses from the plant-unavailable pool vs. N fixation and there are considerable differences in how models treat both processes. In nonsteady-state systems, the accumulation of N in pools with slow turnover rates reduces N available for plant uptake and can be challenging to represent when initializing ESM simulations. Transactional N limitation occurs when N is incorporated into various vegetation and soil pools and becomes available to plants only after it is mineralized, the dynamics of which depends on how ESMs represent decomposition processes in soils. Other challenges for ESMs emerge when considering seasonal to interannual climatic oscillations as they create asynchronies between C and N demand, leading to transient alternations between N surplus and deficit. Proper evaluation of N dynamics in ESMs requires conceptual understanding of the main levers that trigger N limitation, and we highlight key measurements and observations that can help constrain these levers. Two of the biggest challenges are the mechanistic representation of plant controls on N availability and turnover, including N fixation and organic matter decomposition processes.},
author = {Thomas, R. Quinn and Brookshire, E. N. Jack and Gerber, Stefan},
doi = {10.1111/gcb.12813},
isbn = {1365-2486},
issn = {13541013},
journal = {Global Change Biology},
keywords = {Biogeochemical modeling,Carbon cycle,Carbon-climate feedbacks,Climate change,Global biogeochemical models,Land-surface models,Model evaluation,Terrestrial ecosystems modeling},
month = {may},
number = {5},
pages = {1777--1793},
pmid = {25643841},
title = {{Nitrogen limitation on land: how can it occur in Earth system models?}},
url = {http://doi.wiley.com/10.1111/gcb.12813},
volume = {21},
year = {2015}
}
@article{Thomas2018,
abstract = {The global ocean serves as a critical sink for anthropogenic carbon and heat. While significant effort has been dedicated to quantifying the oceanic uptake of these quantities, less research has been conducted on the mechanisms underlying decadal-to-centennial variability in oceanic heat and carbon. Therefore, little is understood about how much such variability may have obscured or reinforced anthropogenic change. Here the relationship between oceanic heat and carbon content is examined in a suite of coupled climate model simulations that use different parameterization settings for mesoscale mixing. The differences in mesoscale mixing result in very different multidecadal variability, especially in the Weddell Sea where the characteristics of deep convection are drastically changed. Although the magnitude and frequency of variability in global heat and carbon content is different across the model simulations, there is a robust anticorrelation between global heat and carbon content in all simulations. Global carbon content variability is primarily driven by Southern Ocean carbon variability. This contrasts with global heat content variability. Global heat content is primarily driven by variability in the southern midlatitudes and tropics, which opposes the Southern Ocean variability.},
author = {Thomas, Jordan and Waugh, Darryn and Gnanadesikan, Anand},
doi = {10.1175/JCLI-D-17-0134.1},
issn = {08948755},
journal = {Journal of Climate},
keywords = {Atmosphere-ocean interaction,Climate models,Coupled models,Oceanic variability,Parameterization},
month = {feb},
number = {4},
pages = {1467--1482},
publisher = {American Meteorological Society},
title = {{Relationship between ocean carbon and heat multidecadal variability}},
url = {https://doi.org/10.1175/JCLI-D-17-},
volume = {31},
year = {2018}
}
@techreport{Thompson2009,
address = {Montreal, QC, Canada},
author = {Thompson, Ian and Mackey, Brendan and Mcnulty, Steven and Mosseler, Alex},
isbn = {92-9225-137-6},
pages = {67},
publisher = {Secretariat of the Convention on Biological Diversity},
series = {Technical Series no. 43},
title = {{Forest Resilience, Biodiversity, and Climate Change. A Synthesis of the Biodiversity/Resilience/Stability Relationship in Forest Ecosystems}},
url = {https://www.cbd.int/doc/publications/cbd-ts-43-en.pdf},
year = {2009}
}
@article{Thompson2018a,
abstract = {Atmospheric measurements show an increase in CH4 from the 1980s to 1998 followed by a period of near-zero growth until 2007. However, from 2007, CH4 has increased again. Understanding the variability in CH4 is critical for climate prediction and climate change mitigation. We examine the role of CH4 sources and the dominant CH4 sink, oxidation by the hydroxyl radical (OH), in atmospheric CH4 variability over the past three decades using observations of CH4, C2H6, and $\delta$13CCH4 in an inversion. From 2006 to 2014, microbial and fossil fuel emissions increased by 36 ± 12 and 15 ± 8 Tg y?1, respectively. Emission increases were partially offset by a decrease in biomass burning of 3 ± 2 Tg y?1 and increase in soil oxidation of 5 ± 6 Tg y?1. A change in the atmospheric sink did not appear to be a significant factor in the recent growth of CH4.},
author = {Thompson, R L and Nisbet, E G and Pisso, I and Stohl, A and Blake, D and Dlugokencky, E J and Helmig, D and White, J W C},
doi = {10.1029/2018GL078127},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {oct},
number = {20},
pages = {11499--11508},
title = {{Variability in Atmospheric Methane From Fossil Fuel and Microbial Sources Over the Last Three Decades}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078127},
volume = {45},
year = {2018}
}
@article{Thompson2019,
author = {Thompson, Rona L. and Lassaletta, L. and Patra, Prabir K. and Wilson, C. and Wells, K. C. and Gressent, A. and Koffi, E. N. and Chipperfield, M. P. and Winiwarter, Wilfried and Davidson, Eric A. and Tian, Hanqin and Canadell, J. G.},
doi = {10.1038/s41558-019-0613-7},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {dec},
number = {12},
pages = {993--998},
title = {{Acceleration of global N2O emissions seen from two decades of atmospheric inversion}},
url = {http://www.nature.com/articles/s41558-019-0613-7},
volume = {9},
year = {2019}
}
@article{Thornhill2020,
author = {Thornhill, Gillian and Collins, William and Olivi{\'{e}}, Dirk and Skeie, Ragnhild B. and Archibald, Alex and Bauer, Susanne and Checa-Garcia, Ramiro and Fiedler, Stephanie and Folberth, Gerd and Gjermundsen, Ada and Horowitz, Larry and Lamarque, Jean-Francois and Michou, Martine and Mulcahy, Jane and Nabat, Pierre and Naik, Vaishali and O'Connor, Fiona M. and Paulot, Fabien and Schulz, Michael and Scott, Catherine E. and S{\'{e}}f{\'{e}}rian, Roland and Smith, Chris and Takemura, Toshihiko and Tilmes, Simone and Tsigaridis, Kostas and Weber, James},
doi = {10.5194/acp-21-1105-2021},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
keywords = {Aerosol,Atmospheric sciences,Biosphere,Chemistry,Climatology,Earth system science,Forcing (mathematics),Methane,Ozone,State variable,Wetland methane emissions},
month = {jan},
number = {2},
pages = {1105--1126},
title = {{Climate-driven chemistry and aerosol feedbacks in CMIP6 Earth system models}},
url = {https://acp.copernicus.org/articles/21/1105/2021/},
volume = {21},
year = {2021}
}
@article{bg-6-2099-2009,
abstract = {Inclusion of fundamental ecological interactions between carbon and nitrogen cycles in the land component of an atmosphere-ocean general circulation model (AOGCM) leads to decreased carbon uptake associated with CO2 fertilization, and increased carbon uptake associated with warming of the climate system. The balance of these two opposing effects is to reduce the fraction of anthropogenic CO2 predicted to be sequestered in land ecosystems. The primary mechanism responsible for increased land carbon storage under radiatively forced climate change is shown to be fertilization of plant growth by increased mineralization of nitrogen directly associated with increased decomposition of soil organic matter under a warming climate, which in this particular model results in a negative gain for the climate-carbon feedback. Estimates for the land and ocean sink fractions of recent anthropogenic emissions are individually within the range of observational estimates, but the combined land plus ocean sink fractions produce an airborne fraction which is too high compared to observations. This bias is likely due in part to an underestimation of the ocean sink fraction. Our results show a significant growth in the airborne fraction of anthropogenic CO2 emissions over the coming century, attributable in part to a steady decline in the ocean sink fraction. Comparison to experimental studies on the fate of radio-labeled nitrogen tracers in temperate forests indicates that the model representation of competition between plants and microbes for new mineral nitrogen resources is reasonable. Our results suggest a weaker dependence of net land carbon flux on soil moisture changes in tropical regions, and a stronger positive growth response to warming in those regions, than predicted by a similar AOGCM implemented without land carbon-nitrogen interactions. We expect that the between-model uncertainty in predictions of future atmospheric CO2 concentration and associated anthropogenic climate change will be reduced as additional climate models introduce carbon-nitrogen cycle interactions in their land components.},
author = {Thornton, P E and Doney, S C and Lindsay, K and Moore, J K and Mahowald, N and Randerson, J T and Fung, I and Lamarque, J.-F. and Feddema, J J and Lee, Y.-H.},
doi = {10.5194/bg-6-2099-2009},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {10},
pages = {2099--2120},
title = {{Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks: results from an atmosphere–ocean general circulation model}},
url = {https://www.biogeosciences.net/6/2099/2009/ http://www.biogeosciences.net/6/2099/2009/},
volume = {6},
year = {2009}
}
@article{Thornton2020,
abstract = {We demonstrate direct eddy covariance (EC) observations of methane (CH 4 ) fluxes between the sea and atmosphere from an icebreaker in the eastern Arctic Ocean. EC-derived CH 4 emissions averaged 4.58, 1.74, and 0.14 mg m −2 day −1 in the Laptev, East Siberian, and Chukchi seas, respectively, corresponding to annual sea-wide fluxes of 0.83, 0.62, and 0.03 Tg year −1 . These EC results answer concerns that previous diffusive emission estimates, which excluded bubbling, may underestimate total emissions. We assert that bubbling dominates sea-air CH 4 fluxes in only small constrained areas: A {\~{}}100-m 2 area of the East Siberian Sea showed sea-air CH 4 fluxes exceeding 600 mg m −2 day −1 ; in a similarly sized area of the Laptev Sea, peak CH 4 fluxes were {\~{}}170 mg m −2 day −1 . Calculating additional emissions below the noise level of our EC system suggests total ESAS CH 4 emissions of 3.02 Tg year −1 , closely matching an earlier diffusive emission estimate of 2.9 Tg year −1 .},
author = {Thornton, Brett F. and Prytherch, John and Andersson, Kristian and Brooks, Ian M. and Salisbury, Dominic and Tjernstr{\"{o}}m, Michael and Crill, Patrick M.},
doi = {10.1126/sciadv.aay7934},
issn = {2375-2548},
journal = {Science Advances},
month = {jan},
number = {5},
pages = {eaay7934},
title = {{Shipborne eddy covariance observations of methane fluxes constrain Arctic sea emissions}},
url = {https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.aay7934},
volume = {6},
year = {2020}
}
@article{doi:10.1002/2016GL068977,
abstract = {Abstract The Laptev and East Siberian Seas have been proposed as a substantial source of methane (CH4) to the atmosphere. During summer 2014, we made unique high-resolution simultaneous measurements of CH4 in the atmosphere above, and surface waters of, the Laptev and East Siberian Seas. Turbulence-driven sea-air fluxes along the ship's track were derived from these observations; an average diffusive flux of 2.99 mg m−2 d−1 was calculated for the Laptev Sea and for the ice-free portions of the western East Siberian Sea, 3.80 mg m−2 d−1. Although seafloor bubble plumes were observed at two locations in the study area, our calculations suggest that regionally, turbulence-driven diffusive flux alone accounts for the observed atmospheric CH4 enhancements, with only a local, limited role for bubble fluxes, in contrast to earlier reports. CH4 in subice seawater in certain areas suggests that a short-lived flux also occurs annually at ice-out.},
author = {Thornton, Brett F and Geibel, Marc C and Crill, Patrick M and Humborg, Christoph and M{\"{o}}rth, Carl-Magnus},
doi = {10.1002/2016GL068977},
journal = {Geophysical Research Letters},
keywords = {Arctic,East Siberian Sea,Laptev Sea,methane,methane flux},
number = {11},
pages = {5869--5877},
title = {{Methane fluxes from the sea to the atmosphere across the Siberian shelf seas}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016GL068977},
volume = {43},
year = {2016}
}
@article{Thornton2016,
abstract = {Abstract Quantification of the present and future contribution to atmospheric methane (CH4) from lakes, wetlands, fluvial systems, and, potentially, coastal waters remains an important unfinished task for balancing the global CH4 budget. Discriminating between these sources is crucial, especially across climate-sensitive Arctic and subarctic landscapes and waters. Yet basic underlying uncertainties remain, in such areas as total wetland area and definitions of wetlands, which can lead to conflation of wetlands and small ponds in regional studies. We discuss how in situ sampling choices, remote sensing limitations, and isotopic signature overlaps can lead to unintentional double-counting of CH4 emissions and propose that this double-counting can explain a pan-Arctic bottom-up estimate from published sources, 59.7 Tg yr−1 (range 36.9–89.4 Tg yr−1) greatly exceeding the most recent top-down inverse modeled estimate of the pan-Arctic CH4 budget (23 ± 5 Tg yr−1).},
author = {Thornton, Brett F. and Wik, Martin and Crill, Patrick M.},
doi = {10.1002/2016GL071772},
isbn = {0094-8276},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {Arctic,budget,inventory,methane,methane sources,top-down},
month = {dec},
number = {24},
pages = {12569--12577},
title = {{Double-counting challenges the accuracy of high-latitude methane inventories}},
url = {http://doi.wiley.com/10.1002/2016GL071772 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2016GL071772},
volume = {43},
year = {2016}
}
@article{Thurner2017,
abstract = {Turnover concepts in state-of-the-art global vegetation models (GVMs) account for various processes, but are often highly simplified and may not include an adequate representation of the dominant processes that shape vegetation carbon turnover rates in real forest ecosystems at a large spatial scale. Here we evaluate vegetation carbon turnover processes in GVMs participating in the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP; including HYBRID4, JeDi, JULES, LPJml, ORCHIDEE, SDGVM, and VISIT) using estimates of vegetation carbon turnover rate (k) derived from a combination of remote sensing based products of biomass and net primary production (NPP). We find that current model limitations lead to considerable biases in the simulated biomass and in k (severe underestimations by all models except JeDi and VISIT compared to observation-based average k), likely contributing to underestimation of positive feedbacks of the northern forest carbon balance to climate change caused by changes in forest mortality. A need for improved turnover concepts related to frost damage, drought and insect outbreaks in order to better reproduce observation-based spatial patterns in k is identified. Since direct frost damage effects on mortality are usually not accounted for in these GVMs, simulated relationships between k and winter length in boreal forests are not consistent between different regions and strongly biased compared to the observation-based relationships. Some models show a response of k to drought in temperate forests as a result of impacts of water availability on NPP, growth efficiency or carbon balance dependent mortality as well as soil or litter moisture effects on leaf turnover or fire. However, further direct drought effects like carbon starvation (only in HYBRID4) or hydraulic failure are usually not taken into account by the investigated GVMs. While they are considered dominant large-scale mortality agents, mortality mechanisms related to insects and pathogens are not explicitly treated in these models.This article is protected by copyright. All rights reserved.},
author = {Thurner, Martin and Beer, Christian and Ciais, Philippe and Friend, Andrew D. and Ito, Akihiko and Kleidon, Axel and Lomas, Mark R. and Quegan, Shaun and Rademacher, Tim T. and Schaphoff, Sibyll and Tum, Markus and Wiltshire, Andy and Carvalhais, Nuno},
doi = {10.1111/gcb.13660},
isbn = {4000113100},
issn = {13541013},
journal = {Global Change Biology},
month = {aug},
number = {8},
pages = {3076--3091},
pmid = {28192628},
title = {{Evaluation of climate-related carbon turnover processes in global vegetation models for boreal and temperate forests}},
url = {https://onlinelibrary.wiley.com/doi/10.1111/gcb.13660 http://doi.wiley.com/10.1111/gcb.13660},
volume = {23},
year = {2017}
}
@article{Tian2018,
abstract = {{\textless}section class="article-section article-section{\_}{\_}abstract" lang="en" data-lang="en" id="section-1-en"{\textgreater} {\textless}h3 class="article-section{\_}{\_}header main main"{\textgreater}Abstract{\textless}/h3{\textgreater} {\textless}div class="article-section{\_}{\_}content en main"{\textgreater} {\textless}p{\textgreater}Our understanding and quantification of global soil nitrous oxide (N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O) emissions and the underlying processes remain largely uncertain. Here we assessed the effects of multiple anthropogenic and natural factors, including nitrogen fertilizer (N) application, atmospheric N deposition, manure N application, land cover change, climate change and rising atmospheric CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater} concentration, on global soil N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O emissions for the period 1861–2016 using a standard simulation protocol with seven process‐based terrestrial biosphere models. Results suggest global soil N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O emissions have increased from 6.3 ± 1.1 Tg N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O‐N yr{\textless}sup{\textgreater}−1{\textless}/sup{\textgreater} in the pre‐industrial period (the 1860s) to 10.0 ± 2.0 Tg N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O‐N yr{\textless}sup{\textgreater}−1{\textless}/sup{\textgreater} in the recent decade (2007‐2016). Cropland soil emissions increased from 0.3 Tg N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O‐N yr{\textless}sup{\textgreater}−1{\textless}/sup{\textgreater} to 3.3 Tg N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O‐N yr{\textless}sup{\textgreater}−1{\textless}/sup{\textgreater} over the same period, accounting for 82{\%} of the total increase. Regionally, China, South Asia and Southeast Asia underwent rapid increases in cropland N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O emissions since the 1970s. However, US cropland N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O emissions had been relatively flat in magnitude since the 1980s, and EU cropland N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O emissions appear to have decreased by 14{\%}. Soil N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O emissions from predominantly natural ecosystems accounted for 67{\%} of the global soil emissions in the recent decade but showed only a relatively small increase of 0.7 ± 0.5 Tg N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O‐N yr{\textless}sup{\textgreater}−1{\textless}/sup{\textgreater} (11{\%}) since the 1860s. In the recent decade, N fertilizer application, N deposition, manure N application and climate change contributed 54{\%}, 26{\%}, 15{\%} and 24{\%}, respectively, to the total increase. Rising atmospheric CO{\textless}sub{\textgreater}2{\textless}/sub{\textgreater} concentration reduced soil N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O emissions by 10{\%} through the enhanced plant N uptake, while land cover change played a minor role. Our estimation here does not account for indirect emissions from soils and the directed emissions from excreta of grazing livestock. To address uncertainties in estimating regional and global soil N{\textless}sub{\textgreater}2{\textless}/sub{\textgreater}O emissions, this study recommends several critical strategies for improving the process‐based simulations. {\textless}/p{\textgreater} {\textless}p{\textgreater}This article is protected by copyright. All rights reserved.{\textless}/p{\textgreater}},
author = {Tian, Hanqin and Yang, Jia and Xu, Rongting and Lu, Chaoqun and Canadell, Josep G and Davidson, Eric A. and Jackson, Robert B. and Arneth, Almut and Chang, Jinfeng and Ciais, Philippe and Gerber, Stefan and Ito, Akihiko and Joos, Fortunat and Lienert, Sebastian and Messina, Palmira and Olin, Stefan and Pan, Shufen and Peng, Changhui and Saikawa, Eri and Thompson, Rona L. and Vuichard, Nicolas and Winiwarter, Wilfried and Zaehle, S{\"{o}}nke and Zhang, Bowen},
doi = {10.1111/gcb.14514},
isbn = {0000000172929},
issn = {13541013},
journal = {Global Change Biology},
month = {feb},
number = {2},
pages = {640--659},
title = {{Global soil nitrous oxide emissions since the preindustrial era estimated by an ensemble of terrestrial biosphere models: Magnitude, attribution, and uncertainty}},
url = {http://doi.wiley.com/10.1111/gcb.14514},
volume = {25},
year = {2019}
}
@article{Tian2020,
author = {Tian, Hanqin and Xu, Rongting and Canadell, Josep G. and Thompson, Rona L. and Winiwarter, Wilfried and Suntharalingam, Parvadha and Davidson, Eric A. and Ciais, Philippe and Jackson, Robert B. and Janssens-Maenhout, Greet and Prather, Michael J. and Regnier, Pierre and Pan, Naiqing and Pan, Shufen and Peters, Glen P. and Shi, Hao and Tubiello, Francesco N. and Zaehle, S{\"{o}}nke and Zhou, Feng and Arneth, Almut and Battaglia, Gianna and Berthet, Sarah and Bopp, Laurent and Bouwman, Alexander F. and Buitenhuis, Erik T. and Chang, Jinfeng and Chipperfield, Martyn P. and Dangal, Shree R. S. and Dlugokencky, Edward and Elkins, James W. and Eyre, Bradley D. and Fu, Bojie and Hall, Bradley and Ito, Akihiko and Joos, Fortunat and Krummel, Paul B. and Landolfi, Angela and Laruelle, Goulven G. and Lauerwald, Ronny and Li, Wei and Lienert, Sebastian and Maavara, Taylor and MacLeod, Michael and Millet, Dylan B. and Olin, Stefan and Patra, Prabir K. and Prinn, Ronald G. and Raymond, Peter A. and Ruiz, Daniel J. and van der Werf, Guido R. and Vuichard, Nicolas and Wang, Junjie and Weiss, Ray F. and Wells, Kelley C. and Wilson, Chris and Yang, Jia and Yao, Yuanzhi},
doi = {10.1038/s41586-020-2780-0},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7828},
pages = {248--256},
title = {{A comprehensive quantification of global nitrous oxide sources and sinks}},
url = {http://www.nature.com/articles/s41586-020-2780-0},
volume = {586},
year = {2020}
}
@article{TIEMEYER2020105838,
abstract = {Drained organic soils are large sources of anthropogenic greenhouse gases (GHG) in many European and Asian countries. Therefore, these soils urgently need to be considered and adequately accounted for when attempting to decrease emissions from the Agriculture and Land Use, Land Use Change and Forestry (LULUCF) sectors. Here, we describe the methodology, data and results of the German approach for measurement, reporting and verification (MRV) of anthropogenic GHG emissions from drained organic soils and outline ways forward towards tracking drainage and rewetting. The methodology was developed for and is currently applied in the German GHG inventory under the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol. Spatial activity data comprise high resolution maps of land-use, type of organic soil and mean annual water table (WT). The WT map was derived by a boosted regression trees model from data of more than 1000 dipwells. Emissions of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) were synthesized from a unique national data set comprising more than 250 annual GHG balances from 118 sites in most land-use categories and types of organic soils. Measurements were performed with harmonized protocols using manual chambers. Non-linear response functions describe the dependency of CO2 and CH4 fluxes on mean annual WT, stratified by land-use where appropriate. Modelling results were aggregated into “implied emission factors” for each land-use category, taking into account the uncertainty of the response functions, the frequency distribution of the WT within each land-use category and further GHG sources such as dissolved organic carbon or CH4 emissions from ditches. IPCC default emission factors were used for these minor GHG sources. In future, response functions could be applied directly when appropriate WT data is available. As no functional relationship was found for N2O emissions, emission factors were calculated as the mean observed flux per land-use category. In Germany, drained organic soils emit more than 55 million tons of GHGs per year, of which 91{\%} are CO2. This is equivalent to around 6.6{\%} of the national GHG emissions in 2014. Thus, they are the largest GHG source from agriculture and LULUCF. The described methodology is applicable on the project scale as well as in other countries where similar data are collected.},
author = {Tiemeyer, B{\"{a}}rbel and Freibauer, Annette and Borraz, Elisa Albiac and Augustin, J{\"{u}}rgen and Bechtold, Michel and Beetz, Sascha and Beyer, Colja and Ebli, Martin and Eickenscheidt, Tim and Fiedler, Sabine and F{\"{o}}rster, Christoph and Gensior, Andreas and Giebels, Michael and Glatzel, Stephan and Heinichen, Jan and Hoffmann, Mathias and H{\"{o}}per, Heinrich and Jurasinski, Gerald and Laggner, Andreas and Leiber-Sauheitl, Katharina and Peichl-Brak, Mandy and Dr{\"{o}}sler, Matthias},
doi = {https://doi.org/10.1016/j.ecolind.2019.105838},
issn = {1470-160X},
journal = {Ecological Indicators},
keywords = {Drainage,Greenhouse gases,MRV,Peatland,Rewetting,mitigation measures},
pages = {105838},
title = {{A new methodology for organic soils in national greenhouse gas inventories: Data synthesis, derivation and application}},
url = {https://www.sciencedirect.com/science/article/pii/S1470160X19308325},
volume = {109},
year = {2020}
}
@article{Tierney2020,
abstract = {As the world warms, there is a profound need to improve projections of climate change. Although the latest Earth system models offer an unprecedented number of features, fundamental uncertainties continue to cloud our view of the future. Past climates provide the only opportunity to observe how the Earth system responds to high carbon dioxide, underlining a fundamental role for paleoclimatology in constraining future climate change. Here, we review the relevancy of paleoclimate information for climate prediction and discuss the prospects for emerging methodologies to further insights gained from past climates. Advances in proxy methods and interpretations pave the way for the use of past climates for model evaluation—a practice that we argue should be widely adopted.},
author = {Tierney, Jessica E. and Poulsen, Christopher J. and Monta{\~{n}}ez, Isabel P. and Bhattacharya, Tripti and Feng, Ran and Ford, Heather L. and H{\"{o}}nisch, B{\"{a}}rbel and Inglis, Gordon N. and Petersen, Sierra V. and Sagoo, Navjit and Tabor, Clay R. and Thirumalai, Kaustubh and Zhu, Jiang and Burls, Natalie J. and Foster, Gavin L. and Godd{\'{e}}ris, Yves and Huber, Brian T. and Ivany, Linda C. and {Kirtland Turner}, Sandra and Lunt, Daniel J. and McElwain, Jennifer C. and Mills, Benjamin J. W. and Otto-Bliesner, Bette L. and Ridgwell, Andy and Zhang, Yi Ge},
doi = {10.1126/science.aay3701},
issn = {0036-8075},
journal = {Science},
month = {nov},
number = {6517},
pages = {eaay3701},
pmid = {33154110},
title = {{Past climates inform our future}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.aay3701},
volume = {370},
year = {2020}
}
@article{Tilbrook2019a,
abstract = {A successful integrated ocean acidification (OA) observing network must include (1) scientists and technicians from a range of disciplines from physics to chemistry to biology to technology development; (2) government, private, and intergovernmental support; (3) regional cohorts working together on regionally specific issues; (4) publicly accessible data from the open ocean to coastal to estuarine systems; (5) close integration with other networks focusing on related measurements or issues including the social and economic consequences of OA; and (6) observation-based informational products useful for decision making such as management of fisheries and aquaculture. The Global Ocean Acidification Observing Network (GOA-ON), a key player in this vision, seeks to expand and enhance geographic extent and availability of coastal and open ocean observing data to ultimately inform adaptive measures and policy action, especially in support of the United Nations 2030 Agenda for Sustainable Development. GOA-ON works to empower and support regional collaborative networks such as the Latin American Ocean Acidification Network, supports new scientists entering the field with training, mentorship, and equipment, refines approaches for tracking biological impacts, and stimulates development of lower-cost methodology and technologies allowing for wider participation of scientists. GOA-ON seeks to collaborate with and complement work done by other observing networks such as those focused on carbon flux into the ocean, tracking of carbon and oxygen in the ocean, observing biological diversity, and determining short- and long-term variability in these and other ocean parameters through space and time.},
author = {Tilbrook, Bronte and Jewett, Elizabeth B and DeGrandpre, Michael D and Hernandez-Ayon, Jose Martin and Feely, Richard A and Gledhill, Dwight K and Hansson, Lina and Isensee, Kirsten and Kurz, Meredith L and Newton, Janet A and Siedlecki, Samantha A and Chai, Fei and Dupont, Sam and Graco, Michelle and Calvo, Eva and Greeley, Dana and Kapsenberg, Lydia and Lebrec, Marine and Pelejero, Carles and Schoo, Katherina L and Telszewski, Maciej},
doi = {10.3389/fmars.2019.00337},
isbn = {2296-7745},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {jun},
pages = {337},
title = {{An Enhanced Ocean Acidification Observing Network: From People to Technology to Data Synthesis and Information Exchange}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00337 https://www.frontiersin.org/article/10.3389/fmars.2019.00337/full},
volume = {6},
year = {2019}
}
@article{Tilmes2016,
abstract = {Decarbonization in the immediate future is required to limit global mean temperature (GMT) increase to 2°C relative to preindustrial conditions, if geoengineering is not considered. Here we use the Community Earth System Model (CESM) to investigate climate outcomes if no mitigation is undertaken until GMT has reached 2°C. We find that late decarbonization in CESM without applying stratospheric sulfur injection (SSI) leads to a peak temperature increase of 3°C and GMT remains above 2° for 160 years. An additional gradual increase and then decrease of SSI over this period reaching about 1.5 times the aerosol burden resulting from the Mount Pinatubo eruption in 1992 would limit the increase in GMT to 2.0° for the specific pathway and model. SSI produces mean and extreme temperatures in CESM comparable to an early decarbonization pathway, but aridity is not mitigated to the same extent.},
author = {Tilmes, S. and Sanderson, B. M. and O'Neill, B. C.},
doi = {10.1002/2016GL070122},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {15},
pages = {8222--8229},
title = {{Climate impacts of geoengineering in a delayed mitigation scenario}},
volume = {43},
year = {2016}
}
@article{Tilmes2018c,
abstract = {Abstract Strategically applied geoengineering is proposed to reduce some of the known side effects of stratospheric aerosol modifications. Specific climate goals could be reached depending on design choices of stratospheric sulfur injections by latitude, altitude, and magnitude. Here we explore in detail the stratospheric chemical and dynamical responses to injections at different altitudes using a fully coupled Earth System Model. Two different scenarios are explored that produce approximately the same global cooling of 2°C over the period 2042–2049, a high‐altitude injection case using 24 Tg SO2/year at 30 hPa (≈25‐km altitude) and a low‐altitude injection case using 32 Tg SO2/year injections at 70 hPa (between 19‐ and 20‐km altitude), with annual injections divided equally between 15°N and 15°S. Both cases result in a warming of the lower tropical stratosphere up to 10 and 15°C for the high‐ and low‐altitude injection case and in substantial increases of stratospheric water vapor of up to 2 and 4 ppm, respectively, compared to no geoengineering conditions. Polar column ozone in the Northern Hemisphere is reduced by up to 18{\%} in March for the high‐altitude injection case and up to 8{\%} for the low‐altitude injection case. However, for winter middle and high northern latitudes, low‐altitude injections result in greater column ozone values than without geoengineering. These changes are mostly driven by dynamics and advection. Antarctic column ozone in 2042–2049 does not recover from present‐day (2002–2009) values for both cases.},
author = {Tilmes, Simone and Richter, Jadwiga H. and Mills, Michael J. and Kravitz, Ben and MacMartin, Douglas G. and Garcia, Rolando R. and Kinnison, Douglas E. and Lamarque, Jean Francois and Tribbia, Joseph and Vitt, Francis},
doi = {10.1002/2017JD028146},
issn = {21698996},
journal = {Journal of Geophysical Research: Atmospheres},
number = {9},
pages = {4654--4673},
title = {{Effects of Different Stratospheric SO2 Injection Altitudes on Stratospheric Chemistry and Dynamics}},
volume = {123},
year = {2018}
}
@article{land8120179,
abstract = {Biochar is one of the most affordable negative emission technologies (NET) at hand for future large-scale deployment of carbon dioxide removal (CDR), which is typically found essential to stabilizing global temperature rise at relatively low levels. Biochar has also attracted attention as a soil amendment capable of improving yield and soil quality and of reducing soil greenhouse gas (GHG) emissions. In this work, we review the literature on biochar production potential and its effects on climate, food security, ecosystems, and toxicity. We identify three key factors that are largely affecting the environmental performance of biochar application to agricultural soils: (1) production condition during pyrolysis, (2) soil conditions and background climate, and (3) field management of biochar. Biochar production using only forest or crop residues can achieve up to 10{\%} of the required CDR for 1.5 {\&}deg; C pathways and about 25{\%} for 2 {\&}deg; C pathways; the consideration of dedicated crops as biochar feedstocks increases the CDR potential up to 15{\&}ndash;35{\%} and 35{\&}ndash;50{\%}, respectively. A quantitative review of life-cycle assessment (LCA) studies of biochar systems shows that the total climate change assessment of biochar ranges between a net emission of 0.04 tCO 2 eq and a net reduction of 1.67 tCO 2 eq per tonnes feedstock. The wide range of values is due to different assumptions in the LCA studies, such as type of feedstock, biochar stability in soils, soil emissions, substitution effects, and methodological issues. Potential trade-offs between climate mitigation and other environmental impact categories include particulate matter, acidification, and eutrophication and mostly depend on the background energy system considered and on whether residues or dedicated feedstocks are used for biochar production. Overall, our review finds that biochar in soils presents relatively low risks in terms of negative environmental impacts and can improve soil quality and that decisions regarding feedstock mix and pyrolysis conditions can be optimized to maximize climate benefits and to reduce trade-offs under different soil conditions. However, more knowledge on the fate of biochar in freshwater systems and as black carbon emissions is required, as they represent potential negative consequences for climate and toxicity. Biochar systems also interact with the climate through many complex mechanisms (i.e., surface albedo, black carbon emissions from soils, etc.) or with water bodies through leaching of nutrients. These effects are complex and the lack of simplified metrics and approaches prevents their routine inclusion in environmental assessment studies. Specific emission factors produced from more sophisticated climate and ecosystem models are instrumental to increasing the resolution and accuracy of environmental sustainability analysis of biochar systems and can ultimately improve the characterization of the heterogeneities of varying local conditions and combinations of type feedstock, conversion process, soil conditions, and application practice.},
author = {Tisserant, Alexandre and Cherubini, Francesco},
doi = {10.3390/land8120179},
issn = {2073-445X},
journal = {Land},
number = {12},
pages = {179},
title = {{Potentials, Limitations, Co-Benefits, and Trade-Offs of Biochar Applications to Soils for Climate Change Mitigation}},
url = {https://www.mdpi.com/2073-445X/8/12/179},
volume = {8},
year = {2019}
}
@article{Tjiputra:2016,
abstract = {Abstract Using an Earth system model, we simulate stratospheric aerosol injection (SAI) on top of the Representative Concentration Pathways 8.5 future scenario. Our idealized method prescribes aerosol concentration, linearly increasing from 2020 to 2100, and thereafter remaining constant until 2200. In the aggressive scenario, the model projects a cooling trend toward 2100 despite warming that persists in the high latitudes. Following SAI termination in 2100, a rapid global warming of 0.35 K yr?1 is simulated in the subsequent 10 years, and the global mean temperature returns to levels close to the reference state, though roughly 0.5 K cooler. In contrast to earlier findings, we show a weak response in the terrestrial carbon sink during SAI implementation in the 21st century, which we attribute to nitrogen limitation. The SAI increases the land carbon uptake in the temperate forest-, grassland-, and shrub-dominated regions. The resultant lower temperatures lead to a reduction in the heterotrophic respiration rate and increase soil carbon retention. Changes in precipitation patterns are key drivers for variability in vegetation carbon. Upon SAI termination, the level of vegetation carbon storage returns to the reference case, whereas the soil carbon remains high. The ocean absorbs nearly 10{\%} more carbon in the geoengineered simulation than in the reference simulation, leading to a ?15 ppm lower atmospheric CO2 concentration in 2100. The largest enhancement in uptake occurs in the North Atlantic. In both hemispheres' polar regions, SAI delays the sea ice melting and, consequently, export production remains low. In the deep water of North Atlantic, SAI-induced circulation changes accelerate the ocean acidification rate and broaden the affected area.},
author = {Tjiputra, J F and Grini, A and Lee, H},
doi = {10.1002/2015JG003045},
isbn = {2169-8953},
issn = {21698953},
journal = {Journal of Geophysical Research: Biogeosciences},
keywords = {climate engineering,land c,ocean biogeochemistry},
month = {jan},
number = {1},
pages = {2--27},
title = {{Impact of idealized future stratospheric aerosol injection on the large-scale ocean and land carbon cycles}},
url = {https://doi.org/10.1002/2015JG003045 http://doi.wiley.com/10.1002/2015JG003045},
volume = {121},
year = {2016}
}
@article{Todd-Brown2013,
abstract = {Abstract. Stocks of soil organic carbon represent a large component of the carbon cycle that may participate in climate change feedbacks, particularly on decadal and centennial timescales. For Earth system models (ESMs), the ability to accurately represent the global distribution of existing soil carbon stocks is a prerequisite for accurately predicting future carbon–climate feedbacks. We compared soil carbon simulations from 11 model centers to empirical data from the Harmonized World Soil Database (HWSD) and the Northern Circumpolar Soil Carbon Database (NCSCD). Model estimates of global soil carbon stocks ranged from 510 to 3040 Pg C, compared to an estimate of 1260 Pg C (with a 95{\%} confidence interval of 890–1660 Pg C) from the HWSD. Model simulations for the high northern latitudes fell between 60 and 820 Pg C, compared to 500 Pg C (with a 95{\%} confidence interval of 380–620 Pg C) for the NCSCD and 290 Pg C for the HWSD. Global soil carbon varied 5.9 fold across models in response to a 2.6-fold variation in global net primary productivity (NPP) and a 3.6-fold variation in global soil carbon turnover times. Model–data agreement was moderate at the biome level (R2 values ranged from 0.38 to 0.97 with a mean of 0.75); however, the spatial distribution of soil carbon simulated by the ESMs at the 1{\&}deg; scale was not well correlated with the HWSD (Pearson correlation coefficients less than 0.4 and root mean square errors from 9.4 to 20.8 kg C m{\&}minus;2). In northern latitudes where the two data sets overlapped, agreement between the HWSD and the NCSCD was poor (Pearson correlation coefficient 0.33), indicating uncertainty in empirical estimates of soil carbon. We found that a reduced complexity model dependent on NPP and soil temperature explained much of the 1{\&}deg; spatial variation in soil carbon within most ESMs (R2 values between 0.62 and 0.93 for 9 of 11 model centers). However, the same reduced complexity model only explained 10{\%} of the spatial variation in HWSD soil carbon when driven by observations of NPP and temperature, implying that other drivers or processes may be more important in explaining observed soil carbon distributions. The reduced complexity model also showed that differences in simulated soil carbon across ESMs were driven by differences in simulated NPP and the parameterization of soil heterotrophic respiration (inter-model R2 = 0.93), not by structural differences between the models. Overall, our results suggest that despite fair global-scale agreement with observational data and moderate agreement at the biome scale, most ESMs cannot reproduce grid-scale variation in soil carbon and may be missing key processes. Future work should focus on improving the simulation of driving variables for soil carbon stocks and modifying model structures to include additional processes.},
author = {Todd-Brown, K E O and Randerson, J T and Post, W M and Hoffman, F M and Tarnocai, C and Schuur, E A G and Allison, S D},
doi = {10.5194/bg-10-1717-2013},
isbn = {1726-4189},
issn = {1726-4189},
journal = {Biogeosciences},
month = {mar},
number = {3},
pages = {1717--1736},
publisher = {Copernicus Publications},
title = {{Causes of variation in soil carbon simulations from CMIP5 Earth system models and comparison with observations}},
url = {https://www.biogeosciences.net/10/1717/2013/bg-10-1717-2013.html https://www.biogeosciences.net/10/1717/2013/},
volume = {10},
year = {2013}
}
@article{Tohjima2019,
author = {Tohjima, Y and Mukai, H and Machida, T and Hoshina, Y and Nakaoka, S.-I.},
doi = {10.5194/acp-19-9269-2019},
journal = {Atmospheric Chemistry and Physics},
number = {14},
pages = {9269--9285},
title = {{Global carbon budgets estimated from atmospheric O2/N2 and CO2 observations in the western Pacific region over a 15-year period}},
url = {https://www.atmos-chem-phys.net/19/9269/2019/},
volume = {19},
year = {2019}
}
@article{Tokarska2018,
abstract = {Carbon budgets provide a useful tool for policymakers to help meet the global climate targets, as they specify total allowable carbon emissions consistent with limiting warming to a given temperature threshold. Non-CO 2 forcings have a net warming effect in the Representative Concentration Pathways (RCP) scenarios, leading to reductions in remaining carbon budgets based on CO 2 forcing alone. Carbon budgets consistent with limiting warming to below 2.0 • C, with and without accounting for the effects of non-CO 2 forcings, were assessed in inconsistent ways by the Intergovernmental Panel on Climate Change (IPCC), making the effects of non-CO 2 forcings hard to identify. Here we use a consistent approach to compare 1.5 • C and 2.0 • C carbon budgets with and without accounting for the effects of non-CO 2 forcings, using CO 2 -only and RCP8.5 simulations. The median allowable carbon budgets for 1.5 • C and 2.0 • C warming are reduced by 257 PgC and 418 PgC, respectively, and the uncertainty ranges on the budgets are reduced by more than a factor of two when accounting for the net warming effects of non-CO 2 forcings. While our overall results are consistent with IPCC, we use a more robust methodology, and explain the narrower uncertainty ranges of carbon budgets when non-CO 2 forcings are included. We demonstrate that most of the reduction in carbon budgets is a result of the direct warming effect of the non-CO 2 forcings, with a secondary contribution from the influence of the non-CO 2 forcings on the carbon cycle. Such carbon budgets are expected to play an increasingly important role in climate change mitigation, thus understanding the influence of non-CO 2 forcings on these budgets and their uncertainties is critical.},
author = {Tokarska, Katarzyna B and Gillett, Nathan P and Arora, Vivek K and Lee, Warren G and Zickfeld, Kirsten},
doi = {10.1088/1748-9326/aaafdd},
issn = {1748-9326},
journal = {Environmental Research Letters},
keywords = {article is available online,carbon budgets,cmip5,cumulative em,cumulative emissions,non-co 2 forcings,supplementary material for this,temperature targets},
month = {mar},
number = {3},
pages = {034039},
title = {{The influence of non-CO2 forcings on cumulative carbon emissions budgets}},
url = {http://stacks.iop.org/1748-9326/13/i=3/a=034039?key=crossref.2b6b0a78eeb66430ec3cf7125e01bc02},
volume = {13},
year = {2018}
}
@article{Tokarska2016,
abstract = {Concrete actions to curtail greenhouse gas emissions have so far been limited on a global scale, and therefore the ultimate magnitude of climate change in the absence of further mitigation is an important consideration for climate policy. Estimates of fossil fuel reserves and resources are highly uncertain, and the amount used under a business-as-usual scenario would depend on prevailing economic and technological conditions. In the absence of global mitigation actions, five trillion tonnes of carbon (5 EgC), corresponding to the lower end of the range of estimates of the total fossil fuel resource, is often cited as an estimate of total cumulative emissions. An approximately linear relationship between global warming and cumulative CO2 emissions is known to hold up to 2 EgC emissions on decadal to centennial timescales; however, in some simple climate models the predicted warming at higher cumulative emissions is less than that predicted by such a linear relationship. Here, using simulations from four comprehensive Earth system models, we demonstrate that CO2-attributable warming continues to increase approximately linearly up to 5 EgC emissions. These models simulate, in response to 5 EgC of CO2 emissions, global mean warming of 6.4–9.5 °C, mean Arctic warming of 14.7–19.5 °C, and mean regional precipitation increases by more than a factor of four. These results indicate that the unregulated exploitation of the fossil fuel resource could ultimately result in considerably more profound climate changes than previously suggested.},
author = {Tokarska, Katarzyna B. and Gillett, Nathan P. and Weaver, Andrew J. and Arora, Vivek K. and Eby, Michael},
doi = {10.1038/nclimate3036},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {sep},
number = {9},
pages = {851--855},
title = {{The climate response to five trillion tonnes of carbon}},
url = {http://www.nature.com/articles/nclimate3036},
volume = {6},
year = {2016}
}
@article{Tokarska2019b,
author = {Tokarska, Katarzyna B. and Zickfeld, Kirsten and Rogelj, Joeri},
doi = {10.1029/2019EF001312},
issn = {2328-4277},
journal = {Earth's Future},
month = {dec},
number = {12},
pages = {1283--1295},
title = {{Path Independence of Carbon Budgets When Meeting a Stringent Global Mean Temperature Target After an Overshoot}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019EF001312},
volume = {7},
year = {2019}
}
@article{Tokarska2019,
author = {Tokarska, Katarzyna B. and Schleussner, Carl-Friedrich and Rogelj, Joeri and Stolpe, Martin B. and Matthews, H. Damon and Pfleiderer, Peter and Gillett, Nathan P.},
doi = {10.1038/s41561-019-0493-5},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {dec},
number = {12},
pages = {964--971},
title = {{Recommended temperature metrics for carbon budget estimates, model evaluation and climate policy}},
url = {http://www.nature.com/articles/s41561-019-0493-5},
volume = {12},
year = {2019}
}
@article{Tokarska2020,
abstract = {Remaining carbon budget specifies the cap on global cumulative CO2 emissions from the present-day onwards that would be in line with limiting global warming to a specific maximum level. In the context of the Paris Agreement, global warming is usually interpreted as the externally-forced response to anthropogenic activities and emissions, but it excludes the natural fluctuations of the climate system known as internal variability. A remaining carbon budget can be calculated from an estimate of the anthropogenic warming to date, and either (i) the ratio of CO2-induced warming to cumulative emissions, known as the Transient Climate Response to Emissions (TCRE), in addition to information on the temperature response to the future evolution of non-CO2 emissions; or (ii) climate model scenario simulations that reach a given temperature threshold. Here we quantify the impact of internal variability on the carbon budgets consistent with the Paris Agreement derived using either approach, and on the TCRE diagnosed from individual models. Our results show that internal variability contributes approximately ±0.09 °C to the overall uncertainty range of the human-induced warming to-date, leading to a spread in the remaining carbon budgets as large as ±50 PgC, when using approach (i). Differences in diagnosed TCRE due to internal variability in individual models can be as large as ±0.1 °C/1000 PgC (5-95{\%} range). Alternatively, spread in the remaining carbon budgets calculated from (ii) using future concentration-driven simulations of large ensembles of CMIP6 and CMIP5 models is estimated at ± 30 PgC and ± 40 PgC (5-95{\%} range). These results are important for model evaluation and imply that caution is needed when interpreting small remaining budgets in policy discussions. We do not question the validity of a carbon budget approach in determining mitigation requirements. However, due to intrinsic uncertainty arising from internal variability, it may only be possible to determine the exact year when a budget is exceeded in hindsight, highlighting the importance of a precautionary approach.},
author = {Tokarska, Katarzyna B and Arora, Vivek K and Gillett, Nathan P and Lehner, Flavio and Rogelj, Joeri and Schleussner, Carl-Friedrich and S{\'{e}}f{\'{e}}rian, Roland and Knutti, Reto},
doi = {10.1088/1748-9326/abaf1b},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {oct},
number = {10},
pages = {104064},
publisher = {IOP Publishing},
title = {{Uncertainty in carbon budget estimates due to internal climate variability}},
url = {https://iopscience.iop.org/article/10.1088/1748-9326/abaf1b},
volume = {15},
year = {2020}
}
@article{Tokarska2018a,
abstract = {The Paris Agreement 1 commits ratifying parties to pursue efforts to limit the global temperature increase to 1.5 °C relative to pre-industrial levels. Carbon budgets2–5 consistent with remaining below 1.5 °C warming, reported in the IPCC Fifth Assessment Report (AR5)2,6,8, are directly based on Earth system model (Coupled Model Intercomparison Project Phase 5) 7 responses, which, on average, warm more than observations in response to historical CO2 emissions and other forcings8,9. These models indicate a median remaining budget of 55 PgC (ref. 10 , base period: year 1870) left to emit from January 2016, the equivalent to approximately five years of emissions at the 2015 rate11,12. Here we calculate warming and carbon budgets relative to the decade 2006–2015, which eliminates model–observation differences in the climate–carbon response over the historical period 9 , and increases the median remaining carbon budget to 208 PgC (33–66{\%} range of 130–255 PgC) from January 2016 (with mean warming of 0.89 °C for 2006–2015 relative to 1861–188013–18). There is little sensitivity to the observational data set used to infer warming that has occurred, and no significant dependence on the choice of emissions scenario. Thus, although limiting median projected global warming to below 1.5 °C is undoubtedly challenging19–21, our results indicate it is not impossible, as might be inferred from the IPCC AR5 carbon budgets2,8.},
author = {Tokarska, Katarzyna B. and Gillett, Nathan P.},
doi = {10.1038/s41558-018-0118-9},
issn = {1758-678X},
journal = {Nature Climate Change},
keywords = {Climate and Earth system modelling,Projection and prediction},
month = {apr},
number = {4},
pages = {296--299},
publisher = {Nature Publishing Group},
title = {{Cumulative carbon emissions budgets consistent with 1.5 °C global warming}},
url = {http://www.nature.com/articles/s41558-018-0118-9},
volume = {8},
year = {2018}
}
@article{Tokarska2015,
abstract = {Artificial removal of CO2 from the atmosphere (also referred to as negative emissions) has been proposed as a means to restore the climate system to a desirable state, should the impacts of climate change become 'dangerous'. Here we explore whether negative emissions are indeed effective in reversing climate change on human timescales, given the potentially counteracting effect of natural carbon sinks and the inertia of the climate system. We designed a range of CO2 emission scenarios, which follow a gradual transition to a zero-carbon energy system and entail implementation of various amounts of net-negative emissions at technologically plausible rates. These scenarios are used to force an Earth System Model of intermediate complexity. Results suggest that while it is possible to revert to a desired level of warming (e.g. 2 °C above pre-industrial) after different levels of overshoot, thermosteric sea level rise is not reversible for at least several centuries, even under assumption of large amounts of negative CO2 emissions. During the net-negative emission phase, artificial CO2 removal is opposed by CO2 outgassing from natural carbon sinks, with the efficiency of CO2 removal—here defined as the drop in atmospheric CO2 per unit negative emission—decreasing with the total amount of negative emissions.},
author = {Tokarska, Katarzyna B and Zickfeld, Kirsten},
doi = {10.1088/1748-9326/10/9/094013},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {sep},
number = {9},
pages = {094013},
publisher = {IOP Publishing},
title = {{The effectiveness of net negative carbon dioxide emissions in reversing anthropogenic climate change}},
url = {http://stacks.iop.org/1748-9326/10/i=9/a=094013?key=crossref.3f327bc2242ffd480c6e7e75d8469641 http://stacks.iop.org/1748-9326/10/i=9/a=094013},
volume = {10},
year = {2015}
}
@article{TONITTO200658,
author = {Tonitto, C and David, M.B. and Drinkwater, L.E.},
doi = {10.1016/j.agee.2005.07.003},
issn = {01678809},
journal = {Agriculture, Ecosystems {\&} Environment},
keywords = {Agroecosystems,Alternative agriculture,Corn,Cover crops,Green manure,Legumes,Meta-analysis,Nitrate leaching,Reactive N,Sorghum,Yield},
month = {jan},
number = {1},
pages = {58--72},
title = {{Replacing bare fallows with cover crops in fertilizer-intensive cropping systems: A meta-analysis of crop yield and N dynamics}},
url = {http://www.sciencedirect.com/science/article/pii/S0167880905003749 https://linkinghub.elsevier.com/retrieve/pii/S0167880905003749},
volume = {112},
year = {2006}
}
@article{Toyama2017,
abstract = {We evaluate the output from a widely used ocean carbon cycle model to identify the subduction and obduction (reemergence) rates of anthropogenic carbon (Cant) for climatological conditions during the World Ocean Circulation Experiment (WOCE) era in 1995 using a new set of Lagrangian diagnostic tools. The principal scientific value of the Lagrangian diagnostics is in providing a new means to connect Cant reemergence pathways to the relatively rapid renewal time scales of mode waters through the overturning circulation. Our main finding is that for this model with 2.04 PgC yr?1 of uptake of Cant via gas exchange, the subduction and obduction rates across the base of the mixed layer (MLbase) are 4.96 and 4.50 PgC yr?1, respectively, which are twice as large as the gas exchange at the surface. Given that there is net accumulation of 0.17 PgC yr?1 in the mixed layer itself, this implies the residual downward Cant transport of 1.40 PgC yr?1 across the MLbase is associated with diffusion. Importantly, the net patterns for subduction and obduction transports of Cant mirror the large-scale patterns for transport of water volume, thereby illustrating the processes controlling Cant uptake. Although the net transfer across the MLbase by compensating subduction and obduction is relatively smaller than the diffusion, the localized pattern of Cant subduction and obduction implies significant regional impacts. The median time scale for reemergence of obducting particles is short ({\textless}10 yr), indicating that reemergence should contribute to limiting future carbon uptake through its contribution to perturbing the Revelle factor for surface waters.},
annote = {doi: 10.1175/JCLI-D-16-0725.1},
author = {Toyama, Katsuya and Rodgers, Keith B and Blanke, Bruno and Iudicone, Daniele and Ishii, Masao and Aumont, Olivier and Sarmiento, Jorge L},
doi = {10.1175/JCLI-D-16-0725.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {nov},
number = {21},
pages = {8615--8631},
publisher = {American Meteorological Society},
title = {{Large reemergence of anthropogenic carbon into the ocean's surface mixed layer sustained by the ocean's overturning circulation}},
url = {https://doi.org/10.1175/JCLI-D-16-0725.1 http://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0725.1},
volume = {30},
year = {2017}
}
@article{Trabucco2008,
abstract = {The implicit hydrologic dimensions of international efforts to mitigate climate change, specifically potential impacts of the Clean Development Mechanism-Afforestation/Reforestation (CDM-AR) provisions of the Kyoto Protocol (KP) on global, regional and local water cycles, are examined. The global impact of the redistribution of water use driven by agriculture and land use change, of which CDM-AR can be a contributing factor, is a major component of ongoing global change and climate change processes. If converted to forest, large areas deemed suitable for CDM-AR would exhibit increases in actual evapotranspiration (AET) and/or decreases in runoff. Almost 20{\%} (144 Mha) of all suitable land showed little or no impact on runoff and another 28{\%} (210 Mha) showed only moderate impact. About 27{\%} (200 Mha) was in the highest impact class, exhibiting an 80-100{\%} decrease in runoff, and prevalent in drier areas (based on Aridity Index (AI)), the semi-arid tropics, and in conversion from grasslands and subsistence agriculture. Significant impacts on local hydrologic cycles were evident, however large impacts were not predicted at regional or global scale due primarily to the current limit on carbon offset projects under the Kyoto Protocol. Predicted decreases in runoff ranged from 54{\%} in drier areas to less than 15{\%} in more humid areas, based on four case studies located across a range of biophysical conditions and project scenarios in Ecuador and Bolivia. Factors other than climate, e.g. upstream/downstream position, were shown to be important in evaluating off-site impacts. This study demonstrates that it will become increasingly important to consider implications on local to regional water resources, and how the hydrologic dimension of CDM-AR impacts on issues of sustainability, local communities, and food security. {\textcopyright} 2008 Elsevier B.V. All rights reserved.},
author = {Trabucco, Antonio and Zomer, Robert J. and Bossio, Deborah A. and van Straaten, Oliver and Verchot, Louis V.},
doi = {10.1016/j.agee.2008.01.015},
issn = {01678809},
journal = {Agriculture, Ecosystems {\&} Environment},
keywords = {Afforestation,Aridity Index,CDM-AR,Clean Development Mechanism,Climate change,Forests,Hydrological modeling,Potential evapotranspiration,Reforestation,Spatial modeling,Trees,Water},
number = {1-2},
pages = {81--97},
title = {{Climate change mitigation through afforestation/reforestation: A global analysis of hydrologic impacts with four case studies}},
volume = {126},
year = {2008}
}
@article{Tran2020,
author = {Tran, Giang T. and Oschlies, Andreas and Keller, David P.},
doi = {10.1029/2019MS001787},
issn = {1942-2466},
journal = {Journal of Advances in Modeling Earth Systems},
month = {apr},
number = {4},
title = {{Comparative Assessment of Climate Engineering Scenarios in the Presence of Parametric Uncertainty}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019MS001787},
volume = {12},
year = {2020}
}
@article{Treat2019,
abstract = {Glacial−interglacial variations in CO 2 and methane in polar ice cores have been attributed, in part, to changes in global wetland extent, but the wetland distribution before the Last Glacial Maximum (LGM, 21 ka to 18 ka) remains virtually unknown. We present a study of global peatland extent and carbon (C) stocks through the last glacial cycle (130 ka to present) using a newly compiled database of 1,063 detailed stratigraphic records of peat deposits buried by mineral sediments, as well as a global peatland model. Quantitative agreement between modeling and observations shows extensive peat accumulation before the LGM in northern latitudes ({\textgreater}40°N), particularly during warmer periods including the last interglacial (130 ka to 116 ka, MIS 5e) and the interstadial (57 ka to 29 ka, MIS 3). During cooling periods of glacial advance and permafrost formation, the burial of northern peatlands by glaciers and mineral sediments decreased active peatland extent, thickness, and modeled C stocks by 70 to 90{\%} from warmer times. Tropical peatland extent and C stocks show little temporal variation throughout the study period. While the increased burial of northern peats was correlated with cooling periods, the burial of tropical peat was predominately driven by changes in sea level and regional hydrology. Peat burial by mineral sediments represents a mechanism for long-term terrestrial C storage in the Earth system. These results show that northern peatlands accumulate significant C stocks during warmer times, indicating their potential for C sequestration during the warming Anthropocene.},
author = {Treat, Claire C. and Kleinen, Thomas and Broothaerts, Nils and Dalton, April S. and Dommain, Ren{\'{e}} and Douglas, Thomas A. and Drexler, Judith Z. and Finkelstein, Sarah A. and Grosse, Guido and Hope, Geoffrey and Hutchings, Jack and Jones, Miriam C. and Kuhry, Peter and Lacourse, Terri and L{\"{a}}hteenoja, Outi and Loisel, Julie and Notebaert, Bastiaan and Payne, Richard J. and Peteet, Dorothy M. and Sannel, A. Britta K. and Stelling, Jonathan M. and Strauss, Jens and Swindles, Graeme T. and Talbot, Julie and Tarnocai, Charles and Verstraeten, Gert and Williams, Christopher J. and Xia, Zhengyu and Yu, Zicheng and V{\"{a}}liranta, Minna and H{\"{a}}ttestrand, Martina and Alexanderson, Helena and Brovkin, Victor},
doi = {10.1073/pnas.1813305116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {mar},
number = {11},
pages = {4822--4827},
title = {{Widespread global peatland establishment and persistence over the last 130,000 y}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1813305116},
volume = {116},
year = {2019}
}
@article{Trimmer2016,
author = {Trimmer, Mark and Chronopoulou, Panagiota-Myrsini and Maanoja, Susanna T. and Upstill-Goddard, Robert C. and Kitidis, Vassilis and Purdy, Kevin J.},
doi = {10.1038/ncomms13451},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {13451},
title = {{Nitrous oxide as a function of oxygen and archaeal gene abundance in the North Pacific}},
url = {http://www.nature.com/articles/ncomms13451},
volume = {7},
year = {2016}
}
@article{Trisos2018a,
abstract = {Solar geoengineering is receiving increased policy attention as a potential tool to offset climate warming. While climate responses to geoengineering have been studied in detail, the potential biodiversity consequences are largely unknown. To avoid extinction, species must either adapt or move to track shifting climates. Here, we assess the effects of the rapid implementa- tion, continuation and sudden termination of geoengineering on climate velocities—the speeds and directions that species would need to move to track changes in climate. Compared to a moderate climate change scenario (RCP4.5), rapid geoengineer- ing implementation reduces temperature velocities towards zero in terrestrial biodiversity hotspots. In contrast, sudden ter- mination increases both ocean and land temperature velocities to unprecedented speeds (global medians {\textgreater} 10 km yr−1 ) that are more than double the temperature velocities for recent and future climate change in global biodiversity hotspots. Furthermore, as climate velocities more than double in speed, rapid climate fragmentation occurs in biomes such as temperate grasslands and forests where temperature and precipitation velocity vectors diverge spatially by {\textgreater} 90°. Rapid geoengineering termination would significantly increase the threats to biodiversity from climate change.},
author = {Trisos, Christopher H. and Amatulli, Giuseppe and Gurevitch, Jessica and Robock, Alan and Xia, Lili and Zambri, Brian},
doi = {10.1038/s41559-017-0431-0},
isbn = {9781424486311},
issn = {2397-334X},
journal = {Nature Ecology {\&} Evolution},
month = {mar},
number = {3},
pages = {475--482},
pmid = {29358608},
title = {{Potentially dangerous consequences for biodiversity of solar geoengineering implementation and termination}},
url = {http://www.nature.com/articles/s41559-017-0431-0},
volume = {2},
year = {2018}
}
@article{Tubiello2020,
abstract = {National, regional and global CO2 emissions and removals from forests were estimated for the period 1990–2020 using as input the country reports of the Global Forest Resources Assessment 2020. The new Food and Agriculture Organization of the United Nations (FAO) estimates, based on a simple carbon stock change approach, update published information on net emissions and removals from forests in relation to (a) net forest conversion and (b) forest land. Results show a significant reduction in global emissions from net forest conversion over the study period, from a mean of 4.3 in 1991–2000 to 2.9 Gt CO2 yr−1 in 2016–2020. At the same time, forest land was a significant carbon sink globally but decreased in strength over the study period, from −3.5 to −2.6 Gt CO2 yr−1. Combining net forest conversion with forest land, our estimates indicated that globally forests were a small net source of CO2 to the atmosphere on average during 1990–2020, with mean net emissions of 0.4 Gt CO2 yr−1. The exception was the brief period 2011–2015, when forest land removals counterbalanced emissions from net forest conversion, resulting in a global net sink of −0.7 Gt CO2 yr−1. Importantly, the new estimates allow for the first time in the literature the characterization of forest emissions and removals for the decade just concluded, 2011–2020, showing that in this period the net contribution of forests to the atmosphere was very small, i.e., a sink of less than −0.2 Gt CO2 yr−1 – an estimate not yet reported in the literature. This near-zero balance was nonetheless the result of large global fluxes of opposite sign, namely net forest conversion emissions of 3.1 Gt CO2 yr−1 counterbalanced by net removals on forest land of −3.3 Gt CO2 yr−1. Finally, we compared our estimates with data independently reported by countries to the United Nations Framework on Climate Change, indicating close agreement between FAO and country emissions and removals estimates. Data from this study are openly available via the Zenodo portal (Tubiello, 2020), with DOI https://doi.org/10.5281/zenodo.3941973, as well as in the FAOSTAT (Food and Agriculture Organization Corporate Statistical Database) emissions database (FAO, 2021a).},
author = {Tubiello, Francesco N. and Conchedda, Giulia and Wanner, Nathan and Federici, Sandro and Rossi, Simone and Grassi, Giacomo},
doi = {10.5194/essd-13-1681-2021},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {apr},
number = {4},
pages = {1681--1691},
title = {{Carbon emissions and removals from forests: new estimates, 1990–2020}},
url = {https://essd.copernicus.org/articles/13/1681/2021/},
volume = {13},
year = {2021}
}
@article{Turco2018,
abstract = {The observed trend towards warmer and drier conditions in southern Europe is projected to continue in the next decades, possibly leading to increased risk of large fires. However, an assessment of climate change impacts on fires at and above the 1.5 °C Paris target is still missing. Here, we estimate future summer burned area in Mediterranean Europe under 1.5, 2, and 3 °C global warming scenarios, accounting for possible modifications of climate-fire relationships under changed climatic conditions owing to productivity alterations. We found that such modifications could be beneficial, roughly halving the fire-intensifying signals. In any case, the burned area is robustly projected to increase. The higher the warming level is, the larger is the increase of burned area, ranging from {\~{}}40{\%} to {\~{}}100{\%} across the scenarios. Our results indicate that significant benefits would be obtained if warming were limited to well below 2 °C.},
author = {Turco, Marco and Rosa-C{\'{a}}novas, Juan Jos{\'{e}} and Bedia, Joaqu{\'{i}}n and Jerez, Sonia and Mont{\'{a}}vez, Juan Pedro and Llasat, Maria Carmen and Provenzale, Antonello},
doi = {10.1038/s41467-018-06358-z},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {3821},
title = {{Exacerbated fires in Mediterranean Europe due to anthropogenic warming projected with non-stationary climate–fire models}},
url = {http://www.nature.com/articles/s41467-018-06358-z},
volume = {9},
year = {2018}
}
@article{Turco2014,
abstract = {We analyse the observed climate-driven changes in summer wildfires and their future evolution in a typical Mediterranean environment (NE Spain). By analysing observed climate and fire data from 1970 to 2007, we estimate the response of fire number (NF) and burned area (BA) to climate trends, disentangling the drivers responsible for long-term and interannual changes by means of a parsimonious Multi Linear Regression model (MLR). In the last forty years, the observed NF trend was negative. Here we show that, if improvements in fire management were not taken into account, the warming climate forcing alone would have led to a positive trend in NF. On the other hand, for BA, higher fuel flammability is counterbalanced by the indirect climate effects on fuel structure (i.e. less favourable conditions for fine-fuel availability and fuel connectivity), leading to a slightly negative trend. Driving the fire model with A1B climate change scenarios based on a set of Regional Climate Models from the ENSEMBLES project indicates that increasing temperatures promote a positive trend in NF if no further improvements in fire management are introduced.},
author = {Turco, Marco and Llasat, Maria-Carmen and von Hardenberg, Jost and Provenzale, Antonello},
doi = {10.1007/s10584-014-1183-3},
issn = {1573-1480},
journal = {Climatic Change},
number = {3},
pages = {369--380},
title = {{Climate change impacts on wildfires in a Mediterranean environment}},
url = {https://doi.org/10.1007/s10584-014-1183-3},
volume = {125},
year = {2014}
}
@article{Turco2016a,
abstract = {Forest fires are a serious environmental hazard in southern Europe. Quantitative assessment of recent trends in fire statistics is important for assessing the possible shifts induced by climate and other environmental/socioeconomic changes in this area. Here we analyse recent fire trends in Portugal, Spain, southern France, Italy and Greece, building on a homogenized fire database integrating official fire statistics provided by several national/EU agencies. During the period 1985-2011, the total annual burned area (BA) displayed a general decreasing trend, with the exception of Portugal, where a heterogeneous signal was found. Considering all countries globally, we found that BA decreased by about 3020 km2 over the 27-year-long study period (i.e. about -66{\%} of the mean historical value). These results are consistent with those obtained on longer time scales when data were available, also yielding predominantly negative trends in Spain and France (1974-2011) and a mixed trend in Portugal (1980-2011). Similar overall results were found for the annual number of fires (NF), which globally decreased by about 12600 in the study period (about -59{\%}), except for Spain where, excluding the provinces along the Mediterranean coast, an upward trend was found for the longer period. We argue that the negative trends can be explained, at least in part, by an increased effort in fire management and prevention after the big fires of the 1980's, while positive trends may be related to recent socioeconomic transformations leading to more hazardous landscape configurations, as well as to the observed warming of recent decades. We stress the importance of fire data homogenization prior to analysis, in order to alleviate spurious effects associated with non-stationarities in the data due to temporal variations in fire detection efforts.},
author = {Turco, Marco and Bedia, Joaqu{\'{i}}n and {Di Liberto}, Fabrizio and Fiorucci, Paolo and {Von Hardenberg}, Jost and Koutsias, Nikos and Llasat, Maria Carmen and Xystrakis, Fotios and Provenzale, Antonello},
doi = {10.1371/journal.pone.0150663},
issn = {19326203},
journal = {PLOS ONE},
number = {3},
pages = {e0150663},
title = {{Decreasing Fires in Mediterranean Europe}},
volume = {11},
year = {2016}
}
@article{Turetsky2014,
author = {Turetsky, Merritt R and Benscoter, Brian and Page, Susan and Rein, Guillermo and van der Werf, Guido R and Watts, Adam},
doi = {10.1038/ngeo2325},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jan},
number = {1},
pages = {11--14},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Global vulnerability of peatlands to fire and carbon loss}},
url = {http://dx.doi.org/10.1038/ngeo2325 http://10.0.4.14/ngeo2325 https://www.nature.com/articles/ngeo2325{\#}supplementary-information http://www.nature.com/articles/ngeo2325},
volume = {8},
year = {2015}
}
@article{Turetsky2020,
abstract = {The permafrost zone is expected to be a substantial carbon source to the atmosphere, yet large-scale models currently only simulate gradual changes in seasonally thawed soil. Abrupt thaw will probably occur in {\textless}20{\%} of the permafrost zone but could affect half of permafrost carbon through collapsing ground, rapid erosion and landslides. Here, we synthesize the best available information and develop inventory models to simulate abrupt thaw impacts on permafrost carbon balance. Emissions across 2.5 million km2 of abrupt thaw could provide a similar climate feedback as gradual thaw emissions from the entire 18 million km2 permafrost region under the warming projection of Representative Concentration Pathway 8.5. While models forecast that gradual thaw may lead to net ecosystem carbon uptake under projections of Representative Concentration Pathway 4.5, abrupt thaw emissions are likely to offset this potential carbon sink. Active hillslope erosional features will occupy 3{\%} of abrupt thaw terrain by 2300 but emit one-third of abrupt thaw carbon losses. Thaw lakes and wetlands are methane hot spots but their carbon release is partially offset by slowly regrowing vegetation. After considering abrupt thaw stabilization, lake drainage and soil carbon uptake by vegetation regrowth, we conclude that models considering only gradual permafrost thaw are substantially underestimating carbon emissions from thawing permafrost.},
author = {Turetsky, Merritt R. and Abbott, Benjamin W. and Jones, Miriam C. and Anthony, Katey Walter and Olefeldt, David and Schuur, Edward A G and Grosse, Guido and Kuhry, Peter and Hugelius, Gustaf and Koven, Charles and Lawrence, David M and Gibson, Carolyn and Sannel, A. Britta K. and McGuire, A David},
doi = {10.1038/s41561-019-0526-0},
issn = {1752-0908},
journal = {Nature Geoscience},
month = {feb},
number = {2},
pages = {138--143},
title = {{Carbon release through abrupt permafrost thaw}},
url = {https://doi.org/10.1038/s41561-019-0526-0 http://www.nature.com/articles/s41561-019-0526-0},
volume = {13},
year = {2020}
}
@article{Turi2016,
abstract = {We reconstruct the evolution of ocean acidification in the California Current System (CalCS) from 1979 through 2012 using hindcast simulations with an eddy-resolving ocean biogeochemical model forced with observation-based variations of wind and fluxes of heat and freshwater. We find that domain-wide pH and in the top 60 m of the water column decreased significantly over these three decades by about −0.02 decade−1 and −0.12 decade−1, respectively. In the nearshore areas of northern California and Oregon, ocean acidification is reconstructed to have progressed much more rapidly, with rates up to 30{\%} higher than the domain-wide trends. Furthermore, ocean acidification penetrated substantially into the thermocline, causing a significant domain-wide shoaling of the aragonite saturation depth of on average −33 m decade−1 and up to −50 m decade−1 in the nearshore area of northern California. This resulted in a coast-wide increase in nearly undersaturated waters and the appearance of waters with , leading to a substantial reduction of habitat suitability. Averaged over the whole domain, the main driver of these trends is the oceanic uptake of anthropogenic CO2 from the atmosphere. However, recent changes in the climatic forcing have substantially modulated these trends regionally. This is particularly evident in the nearshore regions, where the total trends in pH are up to 50{\%} larger and trends in and in the aragonite saturation depth are even twice to three times larger than the purely atmospheric CO2-driven trends. This modulation in the nearshore regions is a result of the recent marked increase in alongshore wind stress, which brought elevated levels of dissolved inorganic carbon to the surface via upwelling. Our results demonstrate that changes in the climatic forcing need to be taken into consideration in future projections of the progression of ocean acidification in coastal upwelling regions.},
author = {Turi, G and Lachkar, Z and Gruber, N and M{\"{u}}nnich, M},
doi = {10.1088/1748-9326/11/1/014007},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jan},
number = {1},
pages = {014007},
publisher = {IOP Publishing},
title = {{Climatic modulation of recent trends in ocean acidification in the California Current System}},
url = {http://dx.doi.org/10.1088/1748-9326/11/1/014007 http://stacks.iop.org/1748-9326/11/i=1/a=014007?key=crossref.4a72b915dda6c80330b4591cf79854e3},
volume = {11},
year = {2016}
}
@article{Turk2019,
abstract = {Time of Emergence (ToE) is the time when a signal emerges from the noise of natural variability. Commonly used in climate science for the detection of anthropogenic forcing, this concept has recently been applied to geochemical variables, to assess the emerging times of anthropogenic ocean acidification (OA), mostly in the open ocean using global climate and Earth System Models. Yet studies of OA variables are scarce within costal margins, due to limited multidecadal time-series observations of carbon parameters. ToE provides important information for decision making regarding the strategic configuration of observing assets, to ensure they are optimally positioned either for signal detection and/or process elicitation and to identify the most suitable variables in discerning OA-related changes. Herein, we present a short overview of ToE estimates on an OA variable, CO2 fugacity f(CO2,sw), in the North American ocean margins, using coastal data from the Surface Ocean CO2 Atlas (SOCAT) V5. ToE suggests an average theoretical timeframe for an OA signal to emerge, of 23(±13) years, but with considerable spatial variability. Most coastal areas are experiencing additional secular and/or multi-decadal forcing(s) that modifies the OA signal, and such forcing may not be sufficiently resolved by current observations. We provide recommendations, which will help scientists and decision makers design and implement OA monitoring systems in the next decade, to address the objectives of OceanObs19 (http://www.oceanobs19.net) in support of the United Nations Decade of Ocean Science for Sustainable Development (2021–2030) (https://en.unesco.org/ocean-decade) and the Sustainable Development Goal (SDG) 14.3 (https://sustainabledevelopment.un.org/sdg14) target to “Minimize and address the impacts of OA.”},
author = {Turk, Daniela and Wang, Hongjie and Hu, Xinping and Gledhill, Dwight K and Wang, Zhaohui Aleck and Jiang, Liqing and Cai, Wei-Jun},
doi = {10.3389/fmars.2019.00091},
isbn = {2296-7745},
issn = {2296-7745},
journal = {Frontiers in Marine Science},
month = {mar},
pages = {91},
title = {{Time of Emergence of Surface Ocean Carbon Dioxide Trends in the North American Coastal Margins in Support of Ocean Acidification Observing System Design}},
url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00091 https://www.frontiersin.org/article/10.3389/fmars.2019.00091/full},
volume = {6},
year = {2019}
}
@article{Turnbull2017,
abstract = {Abstract. We present 60 years of $\Delta$14CO2 measurements from Wellington, New Zealand (41°S, 175°E). The record has been extended and fully revised. New measurements have been used to evaluate the existing record and to replace original measurements where warranted. This is the earliest direct atmospheric $\Delta$14CO2 record and records the rise of the 14C bomb spike and the subsequent decline in $\Delta$14CO2 as bomb 14C moved throughout the carbon cycle and increasing fossil fuel CO2 emissions further decreased atmospheric $\Delta$14CO2. The initially large seasonal cycle in the 1960s reduces in amplitude and eventually reverses in phase, resulting in a small seasonal cycle of about 2‰ in the 2000s. The seasonal cycle at Wellington is dominated by the seasonality of cross-tropopause transport and differs slightly from that at Cape Grim, Australia, which is influenced by anthropogenic sources in winter. $\Delta$14CO2 at Cape Grim and Wellington show very similar trends, with significant differences only during periods of known measurement uncertainty. In contrast, similar clean-air sites in the Northern Hemisphere show a higher and earlier bomb 14C peak, consistent with a 1.4-year interhemispheric exchange time. From the 1970s until the early 2000s, the Northern and Southern Hemisphere $\Delta$14CO2 were quite similar, apparently due to the balance of 14C-free fossil fuel CO2 emissions in the north and 14C-depleted ocean upwelling in the south. The Southern Hemisphere sites have shown a consistent and marked elevation above the Northern Hemisphere sites since the early 2000s, which is most likely due to reduced upwelling of 14C-depleted and carbon-rich deep waters in the Southern Ocean, although an underestimate of fossil fuel CO2 emissions or changes in biospheric exchange are also possible explanations. This developing $\Delta$14CO2 interhemispheric gradient is consistent with recent studies that indicate a reinvigorated Southern Ocean carbon sink since the mid-2000s and suggests that the upwelling of deep waters plays an important role in this change.},
author = {Turnbull, Jocelyn C. and {Mikaloff Fletcher}, Sara E. and Ansell, India and Brailsford, Gordon W. and Moss, Rowena C. and Norris, Margaret W. and Steinkamp, Kay},
doi = {10.5194/acp-17-14771-2017},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {dec},
number = {23},
pages = {14771--14784},
title = {{Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014}},
url = {https://www.atmos-chem-phys.net/17/14771/2017/},
volume = {17},
year = {2017}
}
@article{Turner2017,
abstract = {Methane is the second strongest anthropogenic greenhouse gas and its atmospheric burden has more than doubled since 1850. Methane concentrations stabilized in the early 2000s and began increasing again in 2007. Neither the stabilization nor the recent growth are well understood, as evidenced by multiple competing hypotheses in recent literature. Here we use a multispecies two-box model inversion to jointly constrain 36 y of methane sources and sinks, using ground-based measurements of methane, methyl chloroform, and the C 13 /C 12 ratio in atmospheric methane ($\delta$ 13 CH 4 ) from 1983 through 2015. We find that the problem, as currently formulated, is underdetermined and solutions obtained in previous work are strongly dependent on prior assumptions. Based on our analysis, the mathematically most likely explanation for the renewed growth in atmospheric methane, counterintuitively, involves a 25-Tg/y decrease in methane emissions from 2003 to 2016 that is offset by a 7{\%} decrease in global mean hydroxyl (OH) concentrations, the primary sink for atmospheric methane, over the same period. However, we are still able to fit the observations if we assume that OH concentrations are time invariant (as much of the previous work has assumed) and we then find solutions that are largely consistent with other proposed hypotheses for the renewed growth of atmospheric methane since 2007. We conclude that the current surface observing system does not allow unambiguous attribution of the decadal trends in methane without robust constraints on OH variability, which currently rely purely on methyl chloroform data and its uncertain emissions estimates.},
author = {Turner, Alexander J and Frankenberg, Christian and Wennberg, Paul O and Jacob, Daniel J},
doi = {10.1073/pnas.1616020114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
keywords = {turner2017},
month = {may},
number = {21},
pages = {5367--5372},
title = {{Ambiguity in the causes for decadal trends in atmospheric methane and hydroxyl}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1616020114},
volume = {114},
year = {2017}
}
@article{Tyrrell2002,
abstract = {This paper presents analysis of nitrate, phosphate and silicate data from the Benguela upwelling system. Evidence is presented that suggests denitrification occurring close to shore, and also nutrient trapping. Denitrification leaves an imprint on the water properties in terms of a nitrate deficit, that is to say nitrate concentrations that are significantly less than predicted by multiplying the phosphate concentrations by the Redfield ratio. It is probable that denitrification also causes a decoupling of nitrate and carbon compared to Redfield processes, and large-scale losses of nitrate in the Benguela which are not accompanied by losses of carbon. Nitrate-driven CO2 drawdown following upwelling will be less than it might otherwise be, because of denitrification. Nutrient trapping (secondary remineralisation) is apparent as enhanced phosphate concentrations, some of which are several $\mu$mol higher than in the offshore source waters for upwelling. Waters also become enriched in silicate and to a lesser extent nitrate as they advect across the shelf. By implication the same process should also “supercharge” waters in dissolved inorganic carbon, leading to stronger outgassing of CO2 immediately after upwelling. The effect is again to increase the size of the estimated Benguela upwelling system CO2 source.},
author = {Tyrrell, Toby and Lucas, Michael I.},
doi = {10.1016/S0278-4343(02)00077-8},
issn = {02784343},
journal = {Continental Shelf Research},
month = {nov},
number = {17},
pages = {2497--2511},
publisher = {Pergamon},
title = {{Geochemical evidence of denitrification in the Benguela upwelling system}},
url = {https://www.sciencedirect.com/science/article/pii/S0278434302000778?via{\%}3Dihub https://linkinghub.elsevier.com/retrieve/pii/S0278434302000778},
volume = {22},
year = {2002}
}
@article{Ukkola2016b,
author = {Ukkola, Anna M. and Prentice, I. Colin and Keenan, Trevor F. and van Dijk, Albert I. J. M. and Viney, Neil R. and Myneni, Ranga B. and Bi, Jian},
doi = {10.1038/nclimate2831},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jan},
number = {1},
pages = {75--78},
title = {{Reduced streamflow in water-stressed climates consistent with CO2 effects on vegetation}},
volume = {6},
year = {2016}
}
@article{Ulfsbo2018,
abstract = {The extended multiple linear regression technique is used to determine changes in anthropogenic carbon in the intermediate layers of the Eurasian Basin based on occupations from four cruises between 1996 and 2015. The results show a significant increase in basin-wide anthropogenic carbon storage in the Nansen Basin (0.44–0.73 ± 0.14 mol C{\textperiodcentered}m−2{\textperiodcentered}year−1) and the Amundsen Basin (0.63–1.04 ± 0.09 mol C{\textperiodcentered}m−2{\textperiodcentered}year−1). Over the last two decades, inferred changes in ocean acidification (0.020–0.055 pH units) and calcium carbonate desaturation (0.05–0.18 units) are pronounced and rapid. These results, together with results from carbonate-dynamic box model simulations and 129I tracer distribution simulations, suggest that the accumulation of anthropogenic carbon in the intermediate layers of the Eurasian Basin are consistent with increasing concentrations of anthropogenic carbon in source waters of Atlantic origin entering the Arctic Ocean followed by interior transport. The dissimilar distributions of anthropogenic carbon in the interior Nansen and Amundsen Basins are likely due to differences in the lateral ventilation of the intermediate layers by the return flows and ramifications of the boundary current along the topographic boundaries in the Eurasian Basin.},
author = {Ulfsbo, Adam and Jones, Elizabeth M and Casacuberta, N{\'{u}}ria and Korhonen, Meri and Rabe, Benjamin and Karcher, Michael and van Heuven, Steven M A C},
doi = {10.1029/2017GB005738},
journal = {Global Biogeochemical Cycles},
keywords = {Amundsen Basin,Arctic Ocean,Eurasian Basin,Nansen Basin,anthropogenic carbon,ocean acidification},
number = {9},
pages = {1254--1275},
title = {{Rapid Changes in Anthropogenic Carbon Storage and Ocean Acidification in the Intermediate Layers of the Eurasian Arctic Ocean: 1996–2015}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2017GB005738},
volume = {32},
year = {2018}
}
@techreport{US-EPA2019,
author = {{US EPA}},
pages = {78},
publisher = {United States Environmental Protection Agency (US EPA), Office of Atmospheric Programs (6207A), Washington DC, USA},
series = {EPA-430-R-19-010},
title = {{Global Non-CO2 Greenhouse Gas Emission Projections {\&} Mitigation Potential: 2015–2050}},
url = {https://www.epa.gov/global-mitigation-non-co2-greenhouse-gases},
year = {2019}
}
@article{ValdesPaulJ.BeerlingDavidJ.Johnson2005,
author = {Valdes, Paul J. and Beerling, David J. and Johnson, Colin E.},
doi = {10.1029/2004GL021004},
issn = {0094-8276},
journal = {Geophysical Research Letters},
number = {2},
pages = {L02704},
title = {{The ice age methane budget}},
url = {http://doi.wiley.com/10.1029/2004GL021004},
volume = {32},
year = {2005}
}
@article{VanderWerf2017a,
abstract = {Abstract. Climate, land use, and other anthropogenic and natural drivers have the potential to influence fire dynamics in many regions. To develop a mechanistic understanding of the changing role of these drivers and their impact on atmospheric composition, long-term fire records are needed that fuse information from different satellite and in situ data streams. Here we describe the fourth version of the Global Fire Emissions Database (GFED) and quantify global fire emissions patterns during 1997–2016. The modeling system, based on the Carnegie–Ames–Stanford Approach (CASA) biogeochemical model, has several modifications from the previous version and uses higher quality input datasets. Significant upgrades include (1) new burned area estimates with contributions from small fires, (2) a revised fuel consumption parameterization optimized using field observations, (3) modifications that improve the representation of fuel consumption in frequently burning landscapes, and (4) fire severity estimates that better represent continental differences in burning processes across boreal regions of North America and Eurasia. The new version has a higher spatial resolution (0.25°) and uses a different set of emission factors that separately resolves trace gas and aerosol emissions from temperate and boreal forest ecosystems. Global mean carbon emissions using the burned area dataset with small fires (GFED4s) were 2.2 × 1015 grams of carbon per year (Pg C yr−1) during 1997–2016, with a maximum in 1997 (3.0 Pg C yr−1) and minimum in 2013 (1.8 Pg C yr−1). These estimates were 11 {\%} higher than our previous estimates (GFED3) during 1997–2011, when the two datasets overlapped. This net increase was the result of a substantial increase in burned area (37 {\%}), mostly due to the inclusion of small fires, and a modest decrease in mean fuel consumption (−19 {\%}) to better match estimates from field studies, primarily in savannas and grasslands. For trace gas and aerosol emissions, differences between GFED4s and GFED3 were often larger due to the use of revised emission factors. If small fire burned area was excluded (GFED4 without the s for small fires), average emissions were 1.5 Pg C yr−1. The addition of small fires had the largest impact on emissions in temperate North America, Central America, Europe, and temperate Asia. This small fire layer carries substantial uncertainties; improving these estimates will require use of new burned area products derived from high-resolution satellite imagery. Our revised dataset provides an internally consistent set of burned area and emissions that may contribute to a better understanding of multi-decadal changes in fire dynamics and their impact on the Earth system. GFED data are available from http://www.globalfiredata.org.},
author = {van der Werf, Guido R. and Randerson, James T. and Giglio, Louis and van Leeuwen, Thijs T. and Chen, Yang and Rogers, Brendan M. and Mu, Mingquan and van Marle, Margreet J. E. and Morton, Douglas C. and Collatz, G. James and Yokelson, Robert J. and Kasibhatla, Prasad S.},
doi = {10.5194/essd-9-697-2017},
isbn = {1866-3516},
issn = {1866-3516},
journal = {Earth System Science Data},
month = {sep},
number = {2},
pages = {697--720},
title = {{Global fire emissions estimates during 1997–2016}},
url = {https://www.earth-syst-sci-data.net/9/697/2017/ https://essd.copernicus.org/articles/9/697/2017/},
volume = {9},
year = {2017}
}
@article{Groenigen2017,
abstract = {Abstract Rising levels of atmospheric CO2 frequently stimulate plant inputs to soil, but the consequences of these changes for soil carbon (C) dynamics are poorly understood. Plant-derived inputs can accumulate in the soil and become part of the soil C pool ("new soil C"), or accelerate losses of pre-existing ("old") soil C. The dynamics of the new and old pools will likely differ and alter the long-term fate of soil C, but these separate pools, which can be distinguished through isotopic labeling, have not been considered in past syntheses. Using meta-analysis, we found that while elevated CO2 (ranging from 550 to 800 parts per million by volume) stimulates the accumulation of new soil C in the short term ({\textless}1 year), these effects do not persist in the longer term (1-4 years). Elevated CO2 does not affect the decomposition or the size of the old soil C pool over either temporal scale. Our results are inconsistent with predictions of conventional soil C models and suggest that elevated CO2 might increase turnover rates of new soil C. Because increased turnover rates of new soil C limit the potential for additional soil C sequestration, the capacity of land ecosystems to slow the rise in atmospheric CO2 concentrations may be smaller than previously assumed.},
author = {van Groenigen, Kees Jan and Osenberg, Craig W and Terrer, C{\'{e}}sar and Carrillo, Yolima and Dijkstra, Feike A and Heath, James and Nie, Ming and Pendall, Elise and Phillips, Richard P and Hungate, Bruce A},
doi = {10.1111/gcb.13752},
isbn = {1354-1013},
issn = {13541013},
journal = {Global Change Biology},
month = {oct},
number = {10},
pages = {4420--4429},
title = {{Faster turnover of new soil carbon inputs under increased atmospheric CO2}},
url = {https://doi.org/10.1111/gcb.13752 http://doi.wiley.com/10.1111/gcb.13752},
volume = {23},
year = {2017}
}
@article{VanGroenigen2011,
abstract = {Increasing concentrations of atmospheric carbon dioxide (CO2) can affect biotic and abiotic conditions in soil, such as microbial activity and water content1,2. In turn, these changes might be expected to alter the production and consumption of the important greenhouse gases nitrous oxide (N2O) and methane (CH4) (refs 2, 3). However, studies on fluxes of N2O and CH4 from soil under increased atmospheric CO2 have not been quantitatively synthesized. Here we show, using meta-analysis, that increased CO2 (ranging from 463 to 780 parts per million by volume) stimulates both N2O emissions from upland soils and CH4 emissions from rice paddies and natural wetlands. Because enhanced greenhouse-gas emissions add to the radiative forcing of terrestrial ecosystems, these emissions are expected to negate at least 16.6 per cent of the climate change mitigation potential previously predicted from an increase in the terrestrial carbon sink under increased atmospheric CO2 concentrations4. Our results therefore suggest that the capacity of land ecosystems to slow climate warming has been overestimated.},
author = {van Groenigen, Kees Jan and Osenberg, Craig W and Hungate, Bruce A},
doi = {10.1038/nature10176},
issn = {0028-0836},
journal = {Nature},
month = {jul},
number = {7355},
pages = {214--216},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Increased soil emissions of potent greenhouse gases under increased atmospheric CO2}},
url = {http://dx.doi.org/10.1038/nature10176 http://www.nature.com/doifinder/10.1038/nature10176},
volume = {475},
year = {2011}
}
@article{Varela2015,
abstract = {Changes in coastal upwelling strength have been widely studied since 1990 when Bakun proposed that global warming can induce the intensification of upwelling in coastal areas. Whether present wind trends support this hypothesis remains controversial, as results of previous studies seem to depend on the study area, the length of the time series, the season, and even the database used. In this study, temporal and spatial trends in the coastal upwelling regime worldwide were investigated during upwelling seasons from 1982 to 2010 using a single wind database (Climate Forecast System Reanalysis) with high spatial resolution (0.3°). Of the major upwelling systems, increasing trends were only observed in the coastal areas of Benguela, Peru, Canary, and northern California. A tendency for an increase in upwelling-favourable winds was also identified along several less studied regions, such as the western Australian and southern Caribbean coasts.},
author = {Varela, R and {\'{A}}lvarez, I and Santos, F and DeCastro, M. and G{\'{o}}mez-Gesteira, M},
doi = {10.1038/srep10016},
issn = {2045-2322},
journal = {Scientific Reports},
month = {may},
pages = {10016},
publisher = {Macmillan Publishers Limited},
title = {{Has upwelling strengthened along worldwide coasts over 1982–2010?}},
volume = {5},
year = {2015}
}
@article{Vargas2016,
abstract = {A combined data set, combining data from field campaigns and oceanographic cruises, was used to ascertain the influence of both river discharges and upwelling processes, covering spatial and temporal variation in dissolved inorganic carbon (DIC) and aragonite saturation state. This work was conducted in one of the most productive river-influenced upwelling areas in the South Pacific coasts (36°S). Additionally, further work was also conducted to ascertain the contribution of different DIC sources, influencing the dynamics of DIC along the land-ocean range. Six sampling campaigns were conducted across seven stations at the Biob{\'{i}}o River basin, covering approximately 200 km. Three research cruises were undertaken simultaneously, covering the adjacent continental shelf, including 12 sampling stations for hydrographic measurements. Additionally, six stations were also sampled for chemical analyses, covering summer, winter, and spring conditions over 2010 and 2011. Our results evidenced that seaward extent of the river plume was more evident during the winter field campaign, when highest riverine DIC fluxes were observed. The carbonate system along the river-ocean continuum was very heterogeneous varying over spatial and temporal scales. High DIC and pCO2 were observed in river areas with larger anthropogenic effects. CO2 supersaturation at the river plume was observed during all campaigns due to the influence of low pH river waters in winter/spring and high-pCO2 upwelling waters in summer. $\delta$13CDIC evidenced that main DIC sources along the river and river plume corresponded to the respiration of terrestrial organic matter. We have linked this natural process to the carbonate saturation on the adjacent river-influenced coastal area, suggesting that $\Omega$aragonite undersaturation in surface/subsurface waters is largely modulated by the influence of both river discharge and coastal upwelling events in this productive coastal area. Conditions of low $\Omega$aragonite might impact negatively physiological traits for marine organisms, such as bivalves, gastropods, and crustaceans. Therefore, local populations from river-influenced sites could be inherently more tolerant to ocean acidification than organisms living in regions with lower $\Omega$aragonite variability.},
author = {Vargas, Cristian A and Contreras, Paulina Y and P{\'{e}}rez, Claudia A and Sobarzo, Marcus and Sald{\'{i}}as, Gonzalo S and Salisbury, Joe},
doi = {10.1002/2015JG003213},
issn = {21698953},
journal = {Journal of Geophysical Research: Biogeosciences},
keywords = {0414 Biogeochemical cycles,0428 Carbon cycling,0442 Estuarine and nearshore processes,0454 Isotopic composition and chemistry,4546 Nearshore processes,and modeling,carbon chemistry,coastal upwelling,ocean acidification,processes,river discharge},
month = {jun},
number = {6},
pages = {1468--1483},
title = {{Influences of riverine and upwelling waters on the coastal carbonate system off Central Chile and their ocean acidification implications}},
url = {http://dx.doi.org/10.1002/2015JG003213 http://doi.wiley.com/10.1002/2015JG003213},
volume = {121},
year = {2016}
}
@article{Varney et al., In Review,
abstract = {Carbon cycle feedbacks represent large uncertainties in climate change projections, and the response of soil carbon to climate change contributes the greatest uncertainty to this. Future changes in soil carbon depend on changes in litter and root inputs from plants and especially on reductions in the turnover time of soil carbon ( $\tau$ s ) with warming. An approximation to the latter term for the top one metre of soil ($\Delta$ C s,$\tau$ ) can be diagnosed from projections made with the CMIP6 and CMIP5 Earth System Models (ESMs), and is found to span a large range even at 2 °C of global warming (−196 ± 117 PgC). Here, we present a constraint on $\Delta$ C s,$\tau$ , which makes use of current heterotrophic respiration and the spatial variability of $\tau$ s inferred from observations. This spatial emergent constraint allows us to halve the uncertainty in $\Delta$ C s,$\tau$ at 2 °C to −232 ± 52 PgC.},
author = {Varney, Rebecca M. and Chadburn, Sarah E and Friedlingstein, Pierre and Burke, Eleanor J and Koven, Charles D and Hugelius, Gustaf and Cox, Peter M},
doi = {10.1038/s41467-020-19208-8},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {5544},
title = {{A spatial emergent constraint on the sensitivity of soil carbon turnover to global warming}},
url = {http://www.nature.com/articles/s41467-020-19208-8},
volume = {11},
year = {2020}
}
@article{Veldman2015,
abstract = {Misperceptions about the world's grassy biomes contribute to their alarming rates of loss due to conversion for agriculture and tree plantations, as well as to forest encroachment. To illustrate the causes and consequences of these misperceptions, we show that the World Resources Institute and the International Union for Conservation of Nature misidentified 9 million square kilometers of ancient grassy biomes as providing “opportunities” for forest restoration. Establishment of forests in these grasslands, savannas, and open-canopy woodlands would devastate biodiversity and ecosystem services. Such undesired outcomes are avoidable if the distinct ecologies and conservation needs of forest and grassy biomes become better integrated into science and policy. To start with, scientists should create maps that accurately depict grassy biomes at global and landscape scales. It is also crucial that international environmental agreements (e.g., the United Nations Framework Convention on Climate Change) formally recognize grassy biomes and their environmental values.},
author = {Veldman, Joseph W and Overbeck, Gerhard E and Negreiros, Daniel and Mahy, Gregory and {Le Stradic}, Soizig and Fernandes, G Wilson and Durigan, Giselda and Buisson, Elise and Putz, Francis E and Bond, William J},
doi = {10.1093/biosci/biv118},
issn = {0006-3568},
journal = {BioScience},
month = {sep},
number = {10},
pages = {1011--1018},
title = {{Where tree planting and forest expansion are bad for biodiversity and ecosystem services}},
volume = {65},
year = {2015}
}
@article{Veraverbeke2017,
abstract = {Changes in climate and fire regimes are transforming the boreal forest, the world's largest biome. Boreal North America recently experienced two years with large burned area: 2014 in the Northwest Territories and 2015 in Alaska. Here we use climate, lightning, fire and vegetation data sets to assess the mechanisms contributing to large fire years. We find that lightning ignitions have increased since 1975, and that the 2014 and 2015 events coincided with a record number of lightning ignitions and exceptionally high levels of burning near the northern treeline. Lightning ignition explained more than 55{\%} of the interannual variability in burned area, and was correlated with temperature and precipitation, which are projected to increase by mid-century. The analysis shows that lightning drives interannual and long-term ignition and burned area dynamics in boreal North America, and implies future ignition increases may increase carbon loss while accelerating the northward expansion of boreal forest.},
author = {Veraverbeke, Sander and Rogers, Brendan M. and Goulden, Mike L. and Jandt, Randi R. and Miller, Charles E. and Wiggins, Elizabeth B. and Randerson, James T.},
doi = {10.1038/nclimate3329},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jul},
number = {7},
pages = {529--534},
title = {{Lightning as a major driver of recent large fire years in North American boreal forests}},
url = {http://www.nature.com/articles/nclimate3329},
volume = {7},
year = {2017}
}
@article{Verheijen2019,
abstract = {Biochar application to agricultural soils has been proposed as a way to increase crop production by improving soil chemical and physical properties. Liming potential and improved nutrient exchange on biochar surfaces are the most reported mechanisms. Wherever crops experience drought stress, improvements in soil water holding capacity (WHC) might also be an important mechanism. However, reported effects on soil structure and WHC are mixed. Therefore, we studied the effects of biochar on soil bulk density (BD) and WHC in a laboratory column study using two agricultural soils from Portugal: a sandy and a sandy loam soil. Mixed woody feedstock was pyrolysed at 620 °C, creating a wettable biochar that was used unsorted as well as sieved into large (2–4 mm) and small (0.05–1.00 mm) particles, mixed into the soils at 1, 5, 10 and 20{\%} (by volume), and incubated for 10 days at field capacity to allow aggregation. Soil samples were analysed for BD and WHC using soil columns. We found biochar to decrease soil BD and increase maximum WHC, expressed as gravity-drained equilibrium water content, for both soils. The sandy soil was more responsive with significant effects at the lowest application rate (1{\%}), while the sandy loam soil started to show significant effects at 5{\%} biochar. Small biochar particles reduced the BD of sandy soil more, while large biochar particles caused a greater reduction in the BD of the sandy loam soil. The effect of biochar particle size on WHC was less clear, except for small particles at 20{\%} volumetric concentration, which showed a 60{\%} increase in gravimetric WHC. When expressed as total soil water storage (SWS), 20{\%} biochar incorporation to 15 cm depth would increase the total SWS of sandy soil from 0.56 mm (control) to 0.83–0.91 (mm), and of the sandy loam soil from 0.56 to 0.79–0.96 (mm), depending on biochar particle size. Our results suggest that biochar particle sizes can be used to achieve specific effects in soils, while mechanisms and trade-offs (agro-economic and environmental) need further exploration.},
author = {Verheijen, Frank G A and Zhuravel, Anna and Silva, Fl{\'{a}}vio C and Amaro, Ant{\'{o}}nio and Ben-Hur, Meni and Keizer, Jan Jacob},
doi = {10.1016/j.geoderma.2019.03.044},
issn = {0016-7061},
journal = {Geoderma},
pages = {194--202},
title = {{The influence of biochar particle size and concentration on bulk density and maximum water holding capacity of sandy vs sandy loam soil in a column experiment}},
volume = {347},
year = {2019}
}
@article{Vogel2018,
abstract = {The frequency and intensity of climate extremes is expected to increase in many regions due to anthropogenic climate change. In central Europe extreme temperatures are projected to change more strongly than global mean temperatures, and soil moisture-temperature feedbacks significantly contribute to this regional amplification. Because of their strong societal, ecological and economic impacts, robust projections of temperature extremes are needed. Unfortunately, in current model projections, temperature extremes in central Europe are prone to large uncertainties. In order to understand and potentially reduce the uncertainties of extreme temperature projections in Europe, we analyze global climate models from the CMIP5 (Coupled Model Intercomparison Project Phase 5) ensemble for the business-as-usual high-emission scenario (RCP8.5). We find a divergent behavior in long-term projections of summer precipitation until the end of the 21st century, resulting in a trimodal distribution of precipitation (wet, dry and very dry). All model groups show distinct characteristics for the summer latent heat flux, top soil moisture and temperatures on the hottest day of the year (TXx), whereas for net radiation and large-scale circulation no clear trimodal behavior is detectable. This suggests that different land-atmosphere coupling strengths may be able to explain the uncertainties in temperature extremes. Constraining the full model ensemble with observed present-day correlations between summer precipitation and TXx excludes most of the very dry and dry models. In particular, the very dry models tend to overestimate the negative coupling between precipitation and TXx, resulting in a warming that is too strong. This is particularly relevant for global warming levels above 2°C. For the first time, this analysis allows for the substantial reduction of uncertainties in the projected changes of TXx in global climate models. Our results suggest that long-term temperature changes in TXx in central Europe are about 20{\%} lower than those projected by the multi-model median of the full ensemble. In addition, mean summer precipitation is found to be more likely to stay close to present-day levels. These results are highly relevant for improving estimates of regional climate-change impacts including heat stress, water supply and crop failure for central Europe.},
author = {Vogel, Martha M. and Zscheischler, Jakob and Seneviratne, Sonia I.},
doi = {10.5194/esd-9-1107-2018},
issn = {21904987},
journal = {Earth System Dynamics},
number = {3},
pages = {1107--1125},
title = {{Varying soil moisture–atmosphere feedbacks explain divergent temperature extremes and precipitation projections in central Europe}},
volume = {9},
year = {2018}
}
@article{Voigt2017,
abstract = {The Arctic is warming rapidly, causing permafrost soils to thaw. Vast stocks of nitrogen ({\textgreater}67 billion tons) in the permafrost, accumulated thousands of years ago, could now become available for decomposition, leading to the release of nitrous oxide (N2O) to the atmosphere. N2O is a strong greenhouse gas, almost 300 times more powerful than CO2 for warming the climate. Although carbon dynamics in the Arctic are well studied, the fact that Arctic soils store enormous amounts of nitrogen has received little attention so far. We report that the Arctic may become a substantial source of N2O when the permafrost thaws, and that N2O emissions could occur from surfaces covering almost one-fourth of the entire Arctic.Permafrost in the Arctic is thawing, exposing large carbon and nitrogen stocks for decomposition. Gaseous carbon release from Arctic soils due to permafrost thawing is known to be substantial, but growing evidence suggests that Arctic soils may also be relevant sources of nitrous oxide (N2O). Here we show that N2O emissions from subarctic peatlands increase as the permafrost thaws. In our study, the highest postthaw emissions occurred from bare peat surfaces, a typical landform in permafrost peatlands, where permafrost thaw caused a fivefold increase in emissions (0.56 {\{}$\backslash$textpm{\}} 0.11 vs. 2.81 {\{}$\backslash$textpm{\}} 0.6 mg N2O m-2 d-1). These emission rates match those from tropical forest soils, the world{\{}$\backslash$textquoteright{\}}s largest natural terrestrial N2O source. The presence of vegetation, known to limit N2O emissions in tundra, did decrease (by {\~{}}90{\%}) but did not prevent thaw-induced N2O release, whereas waterlogged conditions suppressed the emissions. We show that regions with high probability for N2O emissions cover one-fourth of the Arctic. Our results imply that the Arctic N2O budget will depend strongly on moisture changes, and that a gradual deepening of the active layer will create a strong noncarbon climate change feedback.},
author = {Voigt, Carolina and Marushchak, Maija E and Lamprecht, Richard E and Jackowicz-Korczy{\'{n}}ski, Marcin and Lindgren, Amelie and Mastepanov, Mikhail and Granlund, Lars and Christensen, Torben R and Tahvanainen, Teemu and Martikainen, Pertti J and Biasi, Christina},
doi = {10.1073/pnas.1702902114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {jun},
number = {24},
pages = {6238--6243},
publisher = {National Academy of Sciences},
title = {{Increased nitrous oxide emissions from Arctic peatlands after permafrost thaw}},
url = {http://www.pnas.org/content/114/24/6238 http://www.pnas.org/lookup/doi/10.1073/pnas.1702902114},
volume = {114},
year = {2017}
}
@article{Voigt2020,
author = {Voigt, Carolina and Marushchak, Maija E. and Abbott, Benjamin W. and Biasi, Christina and Elberling, Bo and Siciliano, Steven D. and Sonnentag, Oliver and Stewart, Katherine J. and Yang, Yuanhe and Martikainen, Pertti J.},
doi = {10.1038/s43017-020-0063-9},
issn = {2662-138X},
journal = {Nature Reviews Earth {\&} Environment},
month = {aug},
number = {8},
pages = {420--434},
title = {{Nitrous oxide emissions from permafrost-affected soils}},
url = {http://www.nature.com/articles/s43017-020-0063-9},
volume = {1},
year = {2020}
}
@article{Volodin2008,
abstract = {The atmosphere-ocean general circulation model with the carbon cycle is coupled to a model of methane evolution, in which methane sources in the soil of wetlands and methane evolution in the atmosphere are calculated. A numerical experiment on the simulation of climate and methane-cycle changes in 1860--2100 has been conducted with the model forced by methane emissions prescribed from scenario A1B. The distribution of the sources of methane from soil agrees with the available estimates and amounts to about 240 Mt/year in the 20th century. The methane flux from soil increases to 340 Mt/year by the end of the 21st century. The model adequately reproduces an increase in the atmospheric methane concentration from 800 ppb in 1860 to about 1800 ppb in 2000, but does not produce the observed stabilization of methane concentration in the early 21st century. By 2060, the methane concentration in the model attains 2700 ppb. The increase in atmospheric methane concentration is due mainly to anthropogenic emissions. A similar numerical experiment with fixed sources of methane from soil at the 1860--1900 level suggests that the maximum methane concentration in the model in this case could amount to 2400 ppb. A temperature increase at the end of the 21st century relative to the 19th century is 3.5{\{}$\backslash$textdegree{\}} for a simulated change in the methane flux from soil and 0.25{\{}$\backslash$textdegree{\}} less for a fixed methane flux.},
author = {Volodin, E M},
doi = {10.1134/S0001433808020023},
issn = {0001-4338},
journal = {Izvestiya, Atmospheric and Oceanic Physics},
month = {apr},
number = {2},
pages = {153--159},
title = {{Methane cycle in the INM RAS climate model}},
url = {https://doi.org/10.1134/S0001433808020023 http://link.springer.com/10.1134/S0001433808020023},
volume = {44},
year = {2008}
}
@article{Vonk2015,
abstract = {Abstract. The Arctic is a water-rich region, with freshwater systems covering about 16 {\%} of the northern permafrost landscape. Permafrost thaw creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current state of knowledge regarding how permafrost thaw affects lentic (still) and lotic (moving) systems, exploring the effects of both thermokarst (thawing and collapse of ice-rich permafrost) and deepening of the active layer (the surface soil layer that thaws and refreezes each year). Within thermokarst, we further differentiate between the effects of thermokarst in lowland areas vs. that on hillslopes. For almost all of the processes that we explore, the effects of thaw vary regionally, and between lake and stream systems. Much of this regional variation is caused by differences in ground ice content, topography, soil type, and permafrost coverage. Together, these modifying factors determine (i) the degree to which permafrost thaw manifests as thermokarst, (ii) whether thermokarst leads to slumping or the formation of thermokarst lakes, and (iii) the manner in which constituent delivery to freshwater systems is altered by thaw. Differences in thaw-enabled constituent delivery can be considerable, with these modifying factors determining, for example, the balance between delivery of particulate vs. dissolved constituents, and inorganic vs. organic materials. Changes in the composition of thaw-impacted waters, coupled with changes in lake morphology, can strongly affect the physical and optical properties of thermokarst lakes. The ecology of thaw-impacted lakes and streams is also likely to change; these systems have unique microbiological communities, and show differences in respiration, primary production, and food web structure that are largely driven by differences in sediment, dissolved organic matter, and nutrient delivery. The degree to which thaw enables the delivery of dissolved vs. particulate organic matter, coupled with the composition of that organic matter and the morphology and stratification characteristics of recipient systems will play an important role in determining the balance between the release of organic matter as greenhouse gases (CO2 and CH4), its burial in sediments, and its loss downstream. The magnitude of thaw impacts on northern aquatic ecosystems is increasing, as is the prevalence of thaw-impacted lakes and streams. There is therefore an urgent need to quantify how permafrost thaw is affecting aquatic ecosystems across diverse Arctic landscapes, and the implications of this change for further climate warming.},
author = {Vonk, J E and Tank, S E and Bowden, W B and Laurion, I and Vincent, W F and Alekseychik, P and Amyot, M and Billet, M F and Can{\'{a}}rio, J and Cory, R M and Deshpande, B N and Helbig, M and Jammet, M and Karlsson, J and Larouche, J and MacMillan, G and Rautio, M and {Walter Anthony}, K M and Wickland, K P},
doi = {10.5194/bg-12-7129-2015},
issn = {1726-4189},
journal = {Biogeosciences},
month = {dec},
number = {23},
pages = {7129--7167},
title = {{Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems}},
url = {https://www.biogeosciences.net/12/7129/2015/},
volume = {12},
year = {2015}
}
@article{Voss2013a,
author = {Voss, Maren and Bange, Hermann W. and Dippner, Joachim W. and Middelburg, Jack J. and Montoya, Joseph P. and Ward, Bess},
doi = {10.1098/rstb.2013.0121},
issn = {0962-8436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
month = {jul},
number = {1621},
pages = {20130121},
title = {{The marine nitrogen cycle: recent discoveries, uncertainties and the potential relevance of climate change}},
url = {https://royalsocietypublishing.org/doi/10.1098/rstb.2013.0121},
volume = {368},
year = {2013}
}
@article{Warlind2014,
abstract = {Abstract. Recently a considerable amount of effort has been put into quantifying how interactions of the carbon and nitrogen cycle affect future terrestrial carbon sinks. Dynamic vegetation models, representing the nitrogen cycle with varying degree of complexity, have shown diverging constraints of nitrogen dynamics on future carbon sequestration. In this study, we use LPJ-GUESS, a dynamic vegetation model employing a detailed individual- and patch-based representation of vegetation dynamics, to evaluate how population dynamics and resource competition between plant functional types, combined with nitrogen dynamics, have influenced the terrestrial carbon storage in the past and to investigate how terrestrial carbon and nitrogen dynamics might change in the future (1850 to 2100; one representative "business-as-usual" climate scenario). Single-factor model experiments of CO2 fertilisation and climate change show generally similar directions of the responses of C–N interactions, compared to the C-only version of the model as documented in previous studies using other global models. Under an RCP 8.5 scenario, nitrogen limitation suppresses potential CO2 fertilisation, reducing the cumulative net ecosystem carbon uptake between 1850 and 2100 by 61{\%}, and soil warming-induced increase in nitrogen mineralisation reduces terrestrial carbon loss by 31{\%}. When environmental changes are considered conjointly, carbon sequestration is limited by nitrogen dynamics up to the present. However, during the 21st century, nitrogen dynamics induce a net increase in carbon sequestration, resulting in an overall larger carbon uptake of 17{\%} over the full period. This contrasts with previous results with other global models that have shown an 8 to 37{\%} decrease in carbon uptake relative to modern baseline conditions. Implications for the plausibility of earlier projections of future terrestrial C dynamics based on C-only models are discussed.},
author = {W{\aa}rlind, D. and Smith, B. and Hickler, T. and Arneth, A.},
doi = {10.5194/bg-11-6131-2014},
isbn = {1726-4170},
issn = {1726-4189},
journal = {Biogeosciences},
month = {nov},
number = {21},
pages = {6131--6146},
title = {{Nitrogen feedbacks increase future terrestrial ecosystem carbon uptake in an individual-based dynamic vegetation model}},
url = {https://www.biogeosciences.net/11/6131/2014/},
volume = {11},
year = {2014}
}
@article{Wakita2017,
abstract = {Abstract We used carbon dioxide (CO2) system data collected during 1999?2015 to investigate ocean acidification at time series sites in the western subarctic region of the North Pacific Ocean. The annual mean pH at station K2 decreased at a rate of 0.0025?±?0.0010 year?1 mostly in response to oceanic uptake of anthropogenic CO2. The Revelle factor increased rapidly (0.046?±?0.022 year?1), an indication that the buffering capacity of this region of the ocean has declined faster than at other time series sites. In the western subarctic region, the pH during the winter decline at a slower rate of 0.0008?±?0.0004 year?1. This was attributed to a reduced rate of increase of dissolved inorganic carbon (DIC) and an increase of total alkalinity (TA). The reduction of DIC increase was caused by the decline of surface water density associated with the pycnocline depression and the reduction of vertical diffusion flux from the upper pycnocline. These physical changes were probably caused by northward shrinkage of the western subarctic gyre and global warming. Meanwhile, the contribution of the density decline to the TA increase is canceled out by that of the reduced vertical diffusive flux. We speculated that the winter TA increase is caused mainly by the accumulation of TA due to the weakened calcification by organisms during the winter.},
annote = {doi: 10.1002/2017JC013002},
author = {Wakita, Masahide and Nagano, Akira and Fujiki, Tetsuichi and Watanabe, Shuichi},
doi = {10.1002/2017JC013002},
issn = {21699275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {carbon dioxide system,ocean acidification,time series observation},
month = {aug},
number = {8},
pages = {6923--6935},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Slow acidification of the winter mixed layer in the subarctic western North Pacific}},
url = {https://doi.org/10.1002/2017JC013002 http://doi.wiley.com/10.1002/2017JC013002},
volume = {122},
year = {2017}
}
@article{Walker2020,
author = {Walker, Anthony P. and {De Kauwe}, Martin G. and Bastos, Ana and Belmecheri, Soumaya and Georgiou, Katerina and Keeling, Ralph F. and McMahon, Sean M. and Medlyn, Belinda E. and Moore, David J. P. and Norby, Richard J. and Zaehle, S{\"{o}}nke and Anderson‐Teixeira, Kristina J. and Battipaglia, Giovanna and Brienen, Roel J. W. and Cabugao, Kristine G. and Cailleret, Maxime and Campbell, Elliott and Canadell, Josep G. and Ciais, Philippe and Craig, Matthew E. and Ellsworth, David S. and Farquhar, Graham D. and Fatichi, Simone and Fisher, Joshua B. and Frank, David C. and Graven, Heather and Gu, Lianhong and Haverd, Vanessa and Heilman, Kelly and Heimann, Martin and Hungate, Bruce A. and Iversen, Colleen M. and Joos, Fortunat and Jiang, Mingkai and Keenan, Trevor F. and Knauer, J{\"{u}}rgen and K{\"{o}}rner, Christian and Leshyk, Victor O. and Leuzinger, Sebastian and Liu, Yao and MacBean, Natasha and Malhi, Yadvinder and McVicar, Tim R. and Penuelas, Josep and Pongratz, Julia and Powell, A. Shafer and Riutta, Terhi and Sabot, Manon E. B. and Schleucher, Juergen and Sitch, Stephen and Smith, William K. and Sulman, Benjamin and Taylor, Benton and Terrer, C{\'{e}}sar and Torn, Margaret S. and Treseder, Kathleen K. and Trugman, Anna T. and Trumbore, Susan E. and Mantgem, Phillip J. and Voelker, Steve L. and Whelan, Mary E. and Zuidema, Pieter A.},
doi = {10.1111/nph.16866},
issn = {0028-646X},
journal = {New Phytologist},
month = {mar},
number = {5},
pages = {2413--2445},
title = {{Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO2}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.16866 https://onlinelibrary.wiley.com/doi/10.1111/nph.16866},
volume = {229},
year = {2021}
}
@article{Walker2019,
author = {Walker, Anthony P. and {De Kauwe}, Martin G. and Medlyn, Belinda E. and Zaehle, S{\"{o}}nke and Iversen, Colleen M. and Asao, Shinichi and Guenet, Bertrand and Harper, Anna and Hickler, Thomas and Hungate, Bruce A. and Jain, Atul K. and Luo, Yiqi and Lu, Xingjie and Lu, Meng and Luus, Kristina and Megonigal, J. Patrick and Oren, Ram and Ryan, Edmund and Shu, Shijie and Talhelm, Alan and Wang, Ying-Ping and Warren, Jeffrey M. and Werner, Christian and Xia, Jianyang and Yang, Bai and Zak, Donald R. and Norby, Richard J.},
doi = {10.1038/s41467-019-08348-1},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {454},
title = {{Decadal biomass increment in early secondary succession woody ecosystems is increased by CO2 enrichment}},
url = {http://www.nature.com/articles/s41467-019-08348-1},
volume = {10},
year = {2019}
}
@article{Walker2015,
author = {Walker, Anthony P. and Zaehle, S{\"{o}}nke and Medlyn, Belinda E. and {De Kauwe}, Martin G. and Asao, Shinichi and Hickler, Thomas and Parton, William and Ricciuto, Daniel M. and Wang, Ying-Ping and W{\aa}rlind, David and Norby, Richard J.},
doi = {10.1002/2014GB004995},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {apr},
number = {4},
pages = {476--495},
title = {{Predicting long-term carbon sequestration in response to CO2 enrichment: How and why do current ecosystem models differ?}},
url = {http://doi.wiley.com/10.1002/2014GB004995},
volume = {29},
year = {2015}
}
@article{Walker2019a,
abstract = {Boreal forest fires emit large amounts of carbon into the atmosphere primarily through the combustion of soil organic matter1–3. During each fire, a portion of this soil beneath the burned layer can escape combustion, leading to a net accumulation of carbon in forests over multiple fire events4. Climate warming and drying has led to more severe and frequent forest fires5–7, which threaten to shift the carbon balance of the boreal ecosystem from net accumulation to net loss1, resulting in a positive climate feedback8. This feedback will occur if organic-soil carbon that escaped burning in previous fires, termed ‘legacy carbon', combusts. Here we use soil radiocarbon dating to quantitatively assess legacy carbon loss in the 2014 wildfires in the Northwest Territories of Canada2. We found no evidence for the combustion of legacy carbon in forests that were older than the historic fire-return interval of northwestern boreal forests9. In forests that were in dry landscapes and less than 60 years old at the time of the fire, legacy carbon that had escaped burning in the previous fire cycle was combusted. We estimate that 0.34 million hectares of young forests ({\textless}60 years) that burned in the 2014 fires could have experienced legacy carbon combustion. This implies a shift to a domain of carbon cycling in which these forests become a net source—instead of a sink—of carbon to the atmosphere over consecutive fires. As boreal wildfires continue to increase in size, frequency and intensity7, the area of young forests that experience legacy carbon combustion will probably increase and have a key role in shifting the boreal carbon balance.},
author = {Walker, Xanthe J and Baltzer, Jennifer L and Cumming, Steven G and Day, Nicola J and Ebert, Christopher and Goetz, Scott and Johnstone, Jill F and Potter, Stefano and Rogers, Brendan M and Schuur, Edward A G and Turetsky, Merritt R and Mack, Michelle C},
doi = {10.1038/s41586-019-1474-y},
issn = {0028-0836},
journal = {Nature},
month = {aug},
number = {7770},
pages = {520--523},
title = {{Increasing wildfires threaten historic carbon sink of boreal forest soils}},
url = {https://doi.org/10.1038/s41586-019-1474-y http://www.nature.com/articles/s41586-019-1474-y},
volume = {572},
year = {2019}
}
@article{Wallace2014,
abstract = {Abstract Increased nutrient loading into estuaries causes the accumulation of algal biomass, and microbial degradation of this organic matter decreases oxygen levels and contributes towards hypoxia. A second, often overlooked consequence of microbial degradation of organic matter is the production of carbon dioxide (CO2) and a lowering of seawater pH. To assess the potential for acidification in eutrophic estuaries, the levels of dissolved oxygen (DO), pH, the partial pressure of carbon dioxide (pCO2), and the saturation state for aragonite ($\Omega$aragonite) were horizontally and vertically assessed during the onset, peak, and demise of low oxygen conditions in systems across the northeast US including Narragansett Bay (RI), Long Island Sound (CT–NY), Jamaica Bay (NY), and Hempstead Bay (NY). Low pH conditions ({\textless}7.4) were detected in all systems during summer and fall months concurrent with the decline in DO concentrations. While hypoxic waters and/or regions in close proximity to sewage discharge had extremely high levels of pCO2, ({\textgreater}3000 $\mu$atm), were acidic pH ({\textless}7.0), and were undersaturated with regard to aragonite ($\Omega$aragonite {\textless} 1), even near-normoxic but eutrophic regions of these estuaries were often relatively acidified (pH {\textless} 7.7) during late summer and/or early fall. The close spatial and temporal correspondence between DO and pH and the occurrence of extremes in these conditions in regions with the most intense nutrient loading indicated that they were primarily driven by microbial respiration. Given that coastal acidification is promoted by nutrient-enhanced organic matter loading and reaches levels that have previously been shown to negatively impact the growth and survival of marine organisms, it may be considered an additional symptom of eutrophication that warrants managerial attention.},
author = {Wallace, Ryan B and Baumann, Hannes and Grear, Jason S and Aller, Robert C and Gobler, Christopher J},
doi = {10.1016/j.ecss.2014.05.027},
issn = {02727714},
journal = {Estuarine, Coastal and Shelf Science},
keywords = {acidification,calcium carbonate saturation,estuary,hypoxia,pH,respiration},
month = {jul},
number = {0},
pages = {1--13},
title = {{Coastal ocean acidification: The other eutrophication problem}},
url = {http://www.sciencedirect.com/science/article/pii/S0272771414001553 http://linkinghub.elsevier.com/retrieve/pii/S0272771414001553 https://linkinghub.elsevier.com/retrieve/pii/S0272771414001553},
volume = {148},
year = {2014}
}
@article{WalterAnthony2016,
abstract = {Permafrost thaw exposes previously frozen soil organic matter to microbial decomposition. This process generates methane and carbon dioxide, and thereby fuels a positive feedback process that leads to further warming and thaw1. Despite widespread permafrost degradation during the past ∼40 years2,3,4, the degree to which permafrost thaw may be contributing to a feedback between warming and thaw in recent decades is not well understood. Radiocarbon evidence of modern emissions of ancient permafrost carbon is also sparse5. Here we combine radiocarbon dating of lake bubble trace-gas methane (113 measurements) and soil organic carbon (289 measurements) for lakes in Alaska, Canada, Sweden and Siberia with numerical modelling of thaw and remote sensing of thermokarst shore expansion. Methane emissions from thermokarst areas of lakes that have expanded over the past 60 years were directly proportional to the mass of soil carbon inputs to the lakes from the erosion of thawing permafrost. Radiocarbon dating indicates that methane age from lakes is nearly identical to the age of permafrost soil carbon thawing around them. Based on this evidence of landscape-scale permafrost carbon feedback, we estimate that 0.2 to 2.5 Pg permafrost carbon was released as methane and carbon dioxide in thermokarst expansion zones of pan-Arctic lakes during the past 60 years.},
author = {{Walter Anthony}, Katey M and Daanen, Ronald and Anthony, Peter and {Schneider von Deimling}, Thomas and Ping, Chien-Lu and Chanton, Jeffrey P and Grosse, Guido},
doi = {10.1038/ngeo2795},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {sep},
number = {9},
pages = {679--682},
publisher = {Nature Publishing Group},
title = {{Methane emissions proportional to permafrost carbon thawed in Arctic lakes since the 1950s}},
url = {http://dx.doi.org/10.1038/ngeo2795 http://www.nature.com/articles/ngeo2795},
volume = {9},
year = {2016}
}
@article{Anthony2014,
abstract = {Observations and modelling show that the deep thermokarst lakes that formed in Siberia and Alaska when the permafrost warmed in the Holocene epoch changed from climate-warming methane sources to climate-cooling carbon sinks about 5,000 years ago.},
author = {{Walter Anthony}, K M and Zimov, S A and Grosse, G and Jones, M C and Anthony, P M and III, F S Chapin and Finlay, J C and Mack, M C and Davydov, S and Frenzel, P and Frolking, S},
doi = {10.1038/nature13560},
issn = {1476-4687},
journal = {Nature},
number = {7510},
pages = {452--456},
title = {{A shift of thermokarst lakes from carbon sources to sinks during the Holocene epoch}},
url = {https://doi.org/10.1038/nature13560},
volume = {511},
year = {2014}
}
@article{WalterAnthony2012,
abstract = {Methane, a potent greenhouse gas, accumulates in subsurface hydrocarbon reservoirs, such as coal beds and natural gas deposits. In the Arctic, permafrost and glaciers form a ‘cryosphere cap' that traps gas leaking from these reservoirs, restricting flow to the atmosphere. With a carbon store of over 1,200 Pg, the Arctic geologic methane reservoir is large when compared with the global atmospheric methane pool of around 5 Pg. As such, the Earth's climate is sensitive to the escape of even a small fraction of this methane. Here, we document the release of 14C-depleted methane to the atmosphere from abundant gas seeps concentrated along boundaries of permafrost thaw and receding glaciers in Alaska and Greenland, using aerial and ground surface survey data and in situ measurements of methane isotopes and flux. We mapped over 150,000 seeps, which we identified as bubble-induced open holes in lake ice. These seeps were characterized by anomalously high methane fluxes, and in Alaska by ancient radiocarbon ages and stable isotope values that matched those of coal bed and thermogenic methane accumulations. Younger seeps in Greenland were associated with zones of ice-sheet retreat since the Little Ice Age. Our findings imply that in a warming climate, disintegration of permafrost, glaciers and parts of the polar ice sheets could facilitate the transient expulsion of 14C-depleted methane trapped by the cryosphere cap.},
author = {{Walter Anthony}, Katey M and Anthony, Peter and Grosse, Guido and Chanton, Jeffrey},
doi = {10.1038/ngeo1480},
issn = {1752-0908},
journal = {Nature Geoscience},
number = {6},
pages = {419--426},
title = {{Geologic methane seeps along boundaries of Arctic permafrost thaw and melting glaciers}},
url = {https://doi.org/10.1038/ngeo1480},
volume = {5},
year = {2012}
}
@article{Wang2014c,
abstract = {Earth system models project that the tropical land carbon sink will decrease in size in response to an increase in warming and drought during this century, probably causing a positive climate feedback. But available data are too limited at present to test the predicted changes in the tropical carbon balance in response to climate change. Long-term atmospheric carbon dioxide data provide a global record that integrates the interannual variability of the global carbon balance. Multiple lines of evidence demonstrate that most of this variability originates in the terrestrial biosphere. In particular, the year-to-year variations in the atmospheric carbon dioxide growth rate (CGR) are thought to be the result of fluctuations in the carbon fluxes of tropical land areas. Recently, the response of CGR to tropical climate interannual variability was used to put a constraint on the sensitivity of tropical land carbon to climate change. Here we use the long-term CGR record from Mauna Loa and the South Pole to show that the sensitivity of CGR to tropical temperature interannual variability has increased by a factor of 1.9 ± 0.3 in the past five decades. We find that this sensitivity was greater when tropical land regions experienced drier conditions. This suggests that the sensitivity of CGR to interannual temperature variations is regulated by moisture conditions, even though the direct correlation between CGR and tropical precipitation is weak. We also find that present terrestrial carbon cycle models do not capture the observed enhancement in CGR sensitivity in the past five decades. More realistic model predictions of future carbon cycle and climate feedbacks require a better understanding of the processes driving the response of tropical ecosystems to drought and warming.},
author = {Wang, Xuhui and Piao, Shilong and Ciais, Philippe and Friedlingstein, Pierre and Myneni, Ranga B. and Cox, Peter and Heimann, Martin and Miller, John and Peng, Shushi and Wang, Tao and Yang, Hui and Chen, Anping},
doi = {10.1038/nature12915},
isbn = {0028-0836},
issn = {0028-0836},
journal = {Nature},
month = {feb},
number = {7487},
pages = {212--215},
pmid = {24463514},
title = {{A two-fold increase of carbon cycle sensitivity to tropical temperature variations}},
url = {https://www.nature.com/articles/nature12915 http://www.nature.com/articles/nature12915},
volume = {506},
year = {2014}
}
@article{Wang2017,
author = {Wang, Yi and Hendy, Ingrid and Napier, Tiffany J.},
doi = {10.1002/2017GL075443},
issn = {0094-8276},
journal = {Geophysical Research Letters},
month = {nov},
number = {22},
pages = {11528--11536},
publisher = {Wiley-Blackwell},
title = {{Climate and Anthropogenic Controls of Coastal Deoxygenation on Interannual to Centennial Timescales}},
url = {http://dx.doi.org/10.1002/2017GL075443 http://doi.wiley.com/10.1002/2017GL075443 https://onlinelibrary.wiley.com/doi/abs/10.1002/2017GL075443},
volume = {44},
year = {2017}
}
@article{Wang2019a,
author = {Wang, Xuan and Jacob, Daniel J. and Eastham, Sebastian D. and Sulprizio, Melissa P. and Zhu, Lei and Chen, Qianjie and Alexander, Becky and Sherwen, Tom{\'{a}}s and Evans, Mathew J. and Lee, Ben H. and Haskins, Jessica D. and Lopez-Hilfiker, Felipe D. and Thornton, Joel A. and Huey, Gregory L. and Liao, Hong},
doi = {10.5194/acp-19-3981-2019},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {mar},
number = {6},
pages = {3981--4003},
title = {{The role of chlorine in global tropospheric chemistry}},
url = {https://acp.copernicus.org/articles/19/3981/2019/},
volume = {19},
year = {2019}
}
@article{Wang2020,
abstract = {Croplands are the single largest anthropogenic source of nitrous oxide (N2O) globally, yet their estimates remain difficult to verify when using Tier 1 and 3 methods of the Intergovernmental Panel on Climate Change (IPCC). Here, we re-evaluate global cropland-N2O emissions in 1961–2014, using N-rate-dependent emission factors (EFs) upscaled from 1206 field observations in 180 global distributed sites and high-resolution N inputs disaggregated from sub-national surveys covering 15593 administrative units. Our results confirm IPCC Tier 1 default EFs for upland crops in 1990–2014, but give a ∼15{\%} lower EF in 1961–1989 and a ∼67{\%} larger EF for paddy rice over the full period. Associated emissions (0.82 ± 0.34 Tg N yr–1) are probably one-quarter lower than IPCC Tier 1 global inventories but close to Tier 3 estimates. The use of survey-based gridded N-input data contributes 58{\%} of this emission reduction, the rest being explained by the use of observation-based non-linear EFs. We conclude that upscaling N2O emissions from site-level observations to global croplands provides a new benchmark for constraining IPCC Tier 1 and 3 methods. The detailed spatial distribution of emission data is expected to inform advancement towards more realistic and effective mitigation pathways.},
author = {Wang, Qihui and Zhou, Feng and Shang, Ziyin and Ciais, Philippe and Winiwarter, Wilfried and Jackson, Robert B and Tubiello, Francesco N and Janssens-Maenhout, Greet and Tian, Hanqin and Cui, Xiaoqing and Canadell, Josep G and Piao, Shilong and Tao, Shu},
doi = {10.1093/nsr/nwz087},
issn = {2095-5138},
journal = {National Science Review},
month = {feb},
number = {2},
pages = {441--452},
title = {{Data-driven estimates of global nitrous oxide emissions from croplands}},
url = {https://academic.oup.com/nsr/article/7/2/441/5530920},
volume = {7},
year = {2020}
}
@article{Wang2018,
abstract = {20 {\%} of total plant uptake in most forest ecosystems but accounted for smaller fractions in boreal forests and grasslands. New P inputs from atmospheric deposition and rock weathering supplied a much smaller fraction of total plant uptake than new N inputs, indicating the importance of internal P recycling within ecosystems to support plant growth. Nutrient-use efficiency, defined as the ratio of gross primary production (GPP) to plant nutrient uptake, were diagnosed from our model results and compared between biomes. Tropical forests had the lowest N-use efficiency and the highest P-use efficiency of the forest biomes. An analysis of sensitivity and uncertainty indicated that the NPP-allocation fractions to leaves, roots, and wood contributed the most to the uncertainties in the estimates of nutrient-use efficiencies. Correcting for biases in NPP-allocation fractions produced more plausible gradients of N- and P-use efficiencies from tropical to boreal ecosystems and highlighted the critical role of accurate measurements of C allocation for understanding the N and P cycles.]]{\textgreater}},
author = {Wang, Yilong and Ciais, Philippe and Goll, Daniel and Huang, Yuanyuan and Luo, Yiqi and Wang, Ying-Ping and Bloom, A. Anthony and Broquet, Gr{\'{e}}goire and Hartmann, Jens and Peng, Shushi and Penuelas, Josep and Piao, Shilong and Sardans, Jordi and Stocker, Benjamin D. and Wang, Rong and Zaehle, S{\"{o}}nke and Zechmeister-Boltenstern, Sophie},
doi = {10.5194/gmd-11-3903-2018},
issn = {1991-9603},
journal = {Geoscientific Model Development},
month = {sep},
number = {9},
pages = {3903--3928},
title = {{GOLUM-CNP v1.0: a data-driven modeling of carbon, nitrogen and phosphorus cycles in major terrestrial biomes}},
url = {https://gmd.copernicus.org/articles/11/3903/2018/},
volume = {11},
year = {2018}
}
@article{Wang2014,
abstract = {Abstract. We have investigated the impact of the assumed nitrous oxide (N2O) increases on stratospheric chemistry and dynamics using a series of idealized simulations with a coupled chemistry-climate model (CCM). In a future cooler stratosphere the net yield of NOy from N2O is shown to decrease in a reference run following the IPCC A1B scenario, but NOy can still be significantly increased by extra increases of N2O over 2001–2050. Over the last decade of simulations, 50{\%} increases in N2O result in a maximal 6{\%} reduction in ozone mixing ratios in the middle stratosphere at around 10 hPa and an average 2{\%} decrease in the total ozone column (TCO) compared with the control run. This enhanced destruction could cause an ozone decline in the first half of this century in the middle stratosphere around 10 hPa, while global TCO still shows an increase at the same time. The results from a multiple linear regression analysis and sensitivity simulations with different forcings show that the chemical effect of N2O increases dominates the N2O-induced ozone depletion in the stratosphere, while the dynamical and radiative effects of N2O increases are overall insignificant. The analysis of the results reveals that the ozone depleting potential of N2O varies with the time period and is influenced by the environmental conditions. For example, carbon dioxide (CO2) increases can strongly offset the ozone depletion effect of N2O.},
author = {Wang, W. and Tian, W. and Dhomse, S. and Xie, F. and Shu, J. and Austin, J.},
doi = {10.5194/acp-14-12967-2014},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {dec},
number = {23},
pages = {12967--12982},
title = {{Stratospheric ozone depletion from future nitrous oxide increases}},
url = {https://acp.copernicus.org/articles/14/12967/2014/},
volume = {14},
year = {2014}
}
@article{Wang2019b,
abstract = {The impacts of biochar addition with nitrogen fertilizer (Urea-N) on greenhouse gas (GHG) fluxes and grain yields are not comprehensively understood. Therefore, we designed a field experiment in an intensive rice–wheat cropping system located in the Taihu Lake region of China and measured CH4 and N2O emissions for 2 consecutive years to examine the impacts of biochar combined with N-fertilizer on rice production and GHG flux. Three field experimental treatments were designed: (1) no N-fertilizer application (N0); (2) 270 kg N ha−1 application (N270); and (3) 270 kg N-fertilizer ha−1 plus 25 t ha−1 biochar application (N270 + C). We found that, compared with urea application alone, biochar applied with Urea-N fertilizer increased N use efficiency (NUE) and resulted in more stable growth of rice yield. In addition, biochar addition increased CH4 emissions by 0.5–37.5{\%} on average during the two consecutive rice-growing seasons, and decreased N2O–N loss by {\~{}} 16.7{\%}. During the first growing season, biochar addition did not significantly affect the global warming potential (GWPt) or the greenhouse gas intensity (GHGI) of rice production (p {\textgreater} 0.05). By contrast, during the second rice-growing season, biochar application significantly increased GWPt and GHGI by 28.9{\%} and 18.8{\%}, respectively, mainly because of increased CH4 emissions. Our results suggest that biochar amendment could improve grain yields and NUE, and increased soil GWPt, resulting in a higher potential environmental cost, but that biochar additions enhance exogenous carbon sequestration by the soil, which could offset the increases in GHG emissions.},
author = {Wang, Shuwei and Ma, Shutan and Shan, Jun and Xia, Yongqiu and Lin, Jinghui and Yan, Xiaoyuan},
doi = {10.1007/s42773-019-00011-8},
issn = {2524-7867},
journal = {Biochar},
number = {2},
pages = {177--186},
title = {{A 2-year study on the effect of biochar on methane and nitrous oxide emissions in an intensive rice–wheat cropping system}},
url = {https://doi.org/10.1007/s42773-019-00011-8},
volume = {1},
year = {2019}
}
@article{Wanninkhof2009,
author = {Wanninkhof, Rik and Asher, William E. and Ho, David T. and Sweeney, Colm and McGillis, Wade R.},
doi = {10.1146/annurev.marine.010908.163742},
issn = {1941-1405},
journal = {Annual Review of Marine Science},
month = {jan},
number = {1},
pages = {213--244},
title = {{Advances in Quantifying Air–Sea Gas Exchange and Environmental Forcing}},
url = {http://www.annualreviews.org/doi/10.1146/annurev.marine.010908.163742},
volume = {1},
year = {2009}
}
@article{Wanninkhof2010,
annote = {From Duplicate 1 (Detecting anthropogenic CO 2 changes in the interior Atlantic Ocean between 1989 and 2005 - Wanninkhof, Rik; Doney, Scott C; Bullister, John L; Levine, Naomi M; Warner, Mark; Gruber, Nicolas)

doi: 10.1029/2010JC006251},
author = {Wanninkhof, Rik and Doney, Scott C. and Bullister, John L. and Levine, Naomi M. and Warner, Mark and Gruber, Nicolas},
doi = {10.1029/2010JC006251},
issn = {0148-0227},
journal = {Journal of Geophysical Research: Oceans},
month = {nov},
number = {C11},
pages = {C11028},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Detecting anthropogenic CO2 changes in the interior Atlantic Ocean between 1989 and 2005}},
url = {https://doi.org/10.1029/2010JC006251 http://doi.wiley.com/10.1029/2010JC006251},
volume = {115},
year = {2010}
}
@article{Wanninkhof2014a,
abstract = {The relationship between gas exchange and wind speed is used extensively for estimating bulk fluxes of atmospheric gases across the air-sea interface. Here, I provide an update on the frequently used method of Wanninkhof (1992). The update of the methodology reflects advances that have occurred over the past two decades in quantifying the input parameters. The general principle of obtaining a relationship constrained by the globally integrated bomb-14CO2 flux into the ocean remains unchanged. The improved relationship is created using revised global ocean 14C inventories and improved wind speed products. Empirical relationships of the Schmidt number, which are necessary to determine the fluxes, are extended to 40°C to facilitate their use in the models. The focus is on the gas exchange of carbon dioxide, but the suggested functionality can be extended to other gases at intermediate winds (≈ 4-15 m s-1). The updated relationship, expressed as k = 0.251 {\textless}U2{\textgreater} (Sc/660)-0.5 where k is the gas transfer velocity, {\textless}U2{\textgreater} is the average squared wind speed, and Sc is the Schmidt number, has a 20{\%} uncertainty. The relationship is in close agreement with recent parameterizations based on results from gas exchange process studies over the ocean. {\textcopyright} 2014, by the American Society of Limnology and Oceanography, Inc.},
author = {Wanninkhof, Rik},
doi = {10.4319/lom.2014.12.351},
issn = {15415856},
journal = {Limnology and Oceanography: Methods},
month = {jun},
number = {6},
pages = {351--362},
publisher = {American Society of Limnology and Oceanography Inc.},
title = {{Relationship between wind speed and gas exchange over the ocean revisited}},
url = {http://doi.wiley.com/10.4319/lom.2014.12.351},
volume = {12},
year = {2014}
}
@article{Warren2017,
abstract = {The climate mitigation potential of tropical peatlands has gained increased attention as Southeast Asian peatlands are being deforested, drained and burned at very high rates, causing globally significant carbon dioxide (CO2) emissions to the atmosphere. We used a process-based dynamic tropical peatland model to explore peat carbon (C) dynamics of several management scenarios within the context of simulated twenty-first century climate change. Simulations of all scenarios with land use, including restoration, indicated net C losses over the twenty-first century ranging from 10 to 100 {\%} of pre-disturbance values. Fire can be the dominant C-loss pathway, particularly in the drier climate scenario we tested. Simulated 100 years of oil palm (Elaeis guineensis) cultivation with an initial prescribed burn resulted in 2400–3000 Mg CO2 ha−1 total emissions. Simulated restoration following one 25-year oil palm rotation reduced total emissions to 440–1200 Mg CO2 ha−1, depending on climate. These results suggest that even under a very optimistic scenario of hydrological and forest restoration and the wettest climate regime, only about one third of the peat C lost to the atmosphere from 25 years of oil palm cultivation can be recovered in the following 75 years if the site is restored. Emissions from a simulated land degradation scenario were most sensitive to climate, with total emissions ranging from 230 to 10,600 Mg CO2 ha−1 over 100 years for the wettest and driest dry season scenarios, respectively. The large difference was driven by increased fire probability. Therefore, peat fire suppression is an effective management tool to maintain tropical peatland C stocks in the near term and should be a high priority for climate mitigation efforts. In total, we estimate emissions from current cleared peatlands and peatlands converted to oil palm in Southeast Asia to be 8.7 Gt CO2 over 100 years with a moderate twenty-first century climate. These emissions could be minimized by effective fire suppression and hydrological restoration.},
author = {Warren, Matthew and Frolking, Steve and Dai, Zhaohua and Kurnianto, Sofyan},
doi = {10.1007/s11027-016-9712-1},
issn = {1573-1596},
journal = {Mitigation and Adaptation Strategies for Global Change},
number = {7},
pages = {1041--1061},
title = {{Impacts of land use, restoration, and climate change on tropical peat carbon stocks in the twenty-first century: implications for climate mitigation}},
url = {https://doi.org/10.1007/s11027-016-9712-1},
volume = {22},
year = {2017}
}
@article{Warwick2016,
abstract = {Abstract. We present a global methane modelling study assessing the sensitivity of Arctic atmospheric CH4 mole fractions, $\delta$13C-CH4 and $\delta$D-CH4 to uncertainties in Arctic methane sources. Model simulations include methane tracers tagged by source and isotopic composition and are compared with atmospheric data at four northern high-latitude measurement sites. We find the model's ability to capture the magnitude and phase of observed seasonal cycles of CH4 mixing ratios, $\delta$13C-CH4 and $\delta$D-CH4 at northern high latitudes is much improved using a later spring kick-off and autumn decline in northern high-latitude wetland emissions than predicted by most process models. Results from our model simulations indicate that recent predictions of large methane emissions from thawing submarine permafrost in the East Siberian Arctic Shelf region could only be reconciled with global-scale atmospheric observations by making large adjustments to high-latitude anthropogenic or wetland emission inventories.},
author = {Warwick, Nicola J. and Cain, Michelle L. and Fisher, Rebecca and France, James L. and Lowry, David and Michel, Sylvia E. and Nisbet, Euan G. and Vaughn, Bruce H. and White, James W. C. and Pyle, John A.},
doi = {10.5194/acp-16-14891-2016},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
keywords = {Warwick2016},
month = {dec},
number = {23},
pages = {14891--14908},
title = {{Using $\delta$13C-CH4 and $\delta$D-CH4 to constrain Arctic methane emissions}},
url = {https://acp.copernicus.org/articles/16/14891/2016/},
volume = {16},
year = {2016}
}
@article{Watanabe2017,
abstract = {Using the outputs of projections under the highest emission scenario of the representative concentration pathways performed by Earth system models (ESMs), we evaluate the ocean acidification rates of subsurface layers of the western North Pacific, where the strongest sink of atmospheric CO2 is found in the mid-latitudes. The low potential vorticity water mass called the North Pacific Subtropical Mode Water (STMW) shows large dissolved inorganic carbon (DIC) concentration increase, and is advected southwestward, so that, in the sea to the south of Japan, DIC concentration increases and ocean acidification occurs faster than in adjacent regions. In the STMW of the Izu-Ogasawara region, the ocean acidification occurs with a pH decrease of {\~{}}0.004 year−1 , a much higher rate than the previously estimated global average (0.0023 year−1), so that the pH decreases by 0.3–0.4 during the twenty-first century and the saturation state of calcite ($\Omega$Ca) decreases from {\~{}}4.8 down to {\~{}}2.4. We find that the ESMs with a deeper mixed layer in the Kuroshio Extension region show a larger increase in DIC concentration within the Izu-Ogasawara region and within the Ryukyu Islands region. Comparing model results with the mixed layer depth obtained from the Argo dataset, we estimate that DIC concentration at a depth of {\~{}}200 m increases by 1.4–1.6 $\mu$mol kg−1 year−1 in the Izu-Ogasawara region and by 1.1–1.4 $\mu$mol kg−1 year−1 in the Ryukyu Islands region toward the end of this century.},
author = {Watanabe, Michio and Kawamiya, Michio},
doi = {10.1007/s10872-017-0431-3},
issn = {1573-868X},
journal = {Journal of Oceanography},
number = {6},
pages = {771--784},
title = {{Remote effects of mixed layer development on ocean acidification in the subsurface layers of the North Pacific}},
url = {https://doi.org/10.1007/s10872-017-0431-3},
volume = {73},
year = {2017}
}
@article{Watson2020a,
abstract = {The ocean is a sink for {\~{}}25{\%} of the atmospheric CO 2 emitted by human activities, an amount in excess of 2 petagrams of carbon per year (PgC yr −1 ). Time-resolved estimates of global ocean-atmosphere CO 2 flux provide an important constraint on the global carbon budget. However, previous estimates of this flux, derived from surface ocean CO 2 concentrations, have not corrected the data for temperature gradients between the surface and sampling at a few meters depth, or for the effect of the cool ocean surface skin. Here we calculate a time history of ocean-atmosphere CO 2 fluxes from 1992 to 2018, corrected for these effects. These increase the calculated net flux into the oceans by 0.8–0.9 PgC yr −1 , at times doubling uncorrected values. We estimate uncertainties using multiple interpolation methods, finding convergent results for fluxes globally after 2000, or over the Northern Hemisphere throughout the period. Our corrections reconcile surface uptake with independent estimates of the increase in ocean CO 2 inventory, and suggest most ocean models underestimate uptake.},
author = {Watson, Andrew J. and Schuster, Ute and Shutler, Jamie D. and Holding, Thomas and Ashton, Ian G. C. and Landsch{\"{u}}tzer, Peter and Woolf, David K. and Goddijn-Murphy, Lonneke},
doi = {10.1038/s41467-020-18203-3},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {4422},
title = {{Revised estimates of ocean-atmosphere CO2 flux are consistent with ocean carbon inventory}},
url = {https://www.nature.com/articles/s41467-020-18203-3},
volume = {11},
year = {2020}
}
@article{Webb2019,
abstract = {Nitrogen pollution and global eutrophication are predicted to increase nitrous oxide (N 2 O) emissions from freshwater ecosystems. Surface waters within agricultural landscapes experience the full impact of these pressures and can contribute substantially to total landscape N 2 O emissions. However, N 2 O measurements to date have focused on flowing waters. Small artificial waterbodies remain greatly understudied in the context of agricultural N 2 O emissions. This study provides a regional analysis of N 2 O measurements in small ({\textless}0.01 km 2 ) artificial reservoirs, of which an estimated 16 million exist globally. We show that 67{\%} of reservoirs were N 2 O sinks (−12 to −2 $\mu$mol N 2 O⋅m −2 ⋅d −1 ) in Canada's largest agricultural area, despite their highly eutrophic status [99 ± 289 µg⋅L −1 chlorophyll-a (Chl- a )]. Generalized additive models indicated that in situ N 2 O concentrations were strongly and nonlinearly related to stratification strength and dissolved inorganic nitrogen content, with the lowest N 2 O levels under conditions of strong water column stability and high algal biomass. Predicted fluxes from previously published models based on lakes, reservoirs, and agricultural waters overestimated measured fluxes on average by 7- to 33-fold, challenging the widely held view that eutrophic N-enriched waters are sources of N 2 O.},
author = {Webb, Jackie R. and Hayes, Nicole M. and Simpson, Gavin L. and Leavitt, Peter R. and Baulch, Helen M. and Finlay, Kerri},
doi = {10.1073/pnas.1820389116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {may},
number = {20},
pages = {9814--9819},
title = {{Widespread nitrous oxide undersaturation in farm waterbodies creates an unexpected greenhouse gas sink}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1820389116},
volume = {116},
year = {2019}
}
@article{Webb2016,
author = {Webb, Elizabeth E and Schuur, Edward A G and Natali, Susan M and Oken, Kiva L and Bracho, Rosvel and Krapek, John P and Risk, David and Nickerson, Nick R},
doi = {10.1002/2014JG002795},
issn = {21698953},
journal = {Journal of Geophysical Research: Biogeosciences},
keywords = {10.1002/2014JG002795 and permafrost,carbon,climate change,tundra,warming experiment,winter},
month = {feb},
number = {2},
pages = {249--265},
title = {{Increased wintertime CO2 loss as a result of sustained tundra warming}},
url = {http://doi.wiley.com/10.1002/2014JG002795},
volume = {121},
year = {2016}
}
@article{Weber2019,
abstract = {Oceanic emissions represent a highly uncertain term in the natural atmospheric methane (CH 4 ) budget, due to the sparse sampling of dissolved CH 4 in the marine environment. Here we overcome this limitation by training machine-learning models to map the surface distribution of methane disequilibrium (∆CH 4 ). Our approach yields a global diffusive CH 4 flux of 2–6TgCH 4 yr −1 from the ocean to the atmosphere, after propagating uncertainties in ∆CH 4 and gas transfer velocity. Combined with constraints on bubble-driven ebullitive fluxes, we place total oceanic CH 4 emissions between 6–12TgCH 4 yr −1 , narrowing the range adopted by recent atmospheric budgets (5–25TgCH 4 yr −1 ) by a factor of three. The global flux is dominated by shallow near-shore environments, where CH 4 released from the seafloor can escape to the atmosphere before oxidation. In the open ocean, our models reveal a significant relationship between ∆CH 4 and primary production that is consistent with hypothesized pathways of in situ methane production during organic matter cycling.},
author = {Weber, Thomas and Wiseman, Nicola A. and Kock, Annette},
doi = {10.1038/s41467-019-12541-7},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {4584},
title = {{Global ocean methane emissions dominated by shallow coastal waters}},
url = {http://www.nature.com/articles/s41467-019-12541-7},
volume = {10},
year = {2019}
}
@article{Wei2009,
abstract = {Geochemical records preserved in the long-lived carbonate skeleton of corals provide one of the few means to reconstruct changes in seawater pH since the commencement of the industrial era. This information is important in not only determining the response of the surface oceans to ocean acidification from enhanced uptake of CO2, but also to better understand the effects of ocean acidification on carbonate secreting organisms such as corals, whose ability to calcify is highly pH dependent. Here we report an ∼200year $\delta$11B isotopic record, extracted from a long-lived Porites coral from the central Great Barrier Reef of Australia. This record covering the period from 1800 to 2004 was sampled at yearly increments from 1940 to the present and 5-year increments prior to 1940. The $\delta$11B isotopic compositions reflect variations in seawater pH, and the $\delta$13C changes in the carbon composition of surface water due to fossil fuel burning over this period. In addition complementary Ba/Ca, $\delta$18O and Mg/Ca data was obtained providing proxies for terrestrial runoff, salinity and temperature changes over the past 200years in this region. Positive thermal ionization mass spectrometry (PTIMS) method was utilized in order to enable the highest precision and most accurate measurements of $\delta$11B values. The internal precision and reproducibility for $\delta$11B of our measurements are better than ±0.2‰ (2$\sigma$), which translates to a precision of better than ±0.02 pH units. Our results indicate that the long-term pre-industrial variation of seawater pH in this region is partially related to the decadal–interdecadal variability of atmospheric and oceanic anomalies in the Pacific. In the periods around 1940 and 1998 there are also rapid oscillations in $\delta$11B compositions equivalent changes in pH of almost 0.5U. The 1998 oscillation is co-incident with a major coral bleaching event indicating the sensitivity of skeletal $\delta$11B compositions to loss of zooxanthellate symbionts. Importantly, from the 1940s to the present-day, there is a general overall trend of ocean acidification with pH decreasing by about 0.2–0.3U, the range being dependent on the value assumed for the fractionation factor $\alpha$(B3–B4) of the boric acid and borate species in seawater. Correlations of $\delta$11B with $\delta$13C during this interval indicate that the increasing trend towards ocean acidification over the past 60years in this region is the result of enhanced dissolution of CO2 in surface waters from the rapidly increasing levels of atmospheric CO2, mainly from fossil fuel burning. This suggests that the increased levels of anthropogenic CO2 in atmosphere has already caused a significant trend towards acidification in the oceans during the past decades. Observations of surprisingly large decreases in pH across important carbonate producing regions, such as the Great Barrier Reef of Australia, raise serious concerns about the impact of Greenhouse gas emissions on coral calcification.},
author = {Wei, Gangjian and McCulloch, Malcolm T and Mortimer, Graham and Deng, Wengfeng and Xie, Luhua},
doi = {10.1016/j.gca.2009.02.009},
issn = {00167037},
journal = {Geochimica et Cosmochimica Acta},
month = {apr},
number = {8},
pages = {2332--2346},
title = {{Evidence for ocean acidification in the Great Barrier Reef of Australia}},
url = {http://www.sciencedirect.com/science/article/pii/S0016703709000969 https://linkinghub.elsevier.com/retrieve/pii/S0016703709000969},
volume = {73},
year = {2009}
}
@article{Wei2015a,
abstract = {Abstract Long-term seawater pH records are essential for evaluating the rates of ocean acidification (OA) driven by anthropogenic emissions. Widespread, natural decadal variability in seawater pH superimposes on the long-term anthropogenic variations, likely influencing the OA rates estimated from the pH records. Here, we report a record of annual seawater pH estimated using the $\delta$11B proxy over the past 159 years reconstructed from a Porites coral collected to the east of Hainan Island in the northern South China Sea (SCS). By coupling this time series with previously reported long-term seawater pH records in the West Pacific, the decadal variability in seawater pH records and its possible driving mechanisms were investigated. The results indicate that large decadal variability in seawater pH has occurred off eastern Hainan Island over the past 159 years, in agreement with previous records. The Qiongdong upwelling system, which controls nutrient supplies, regulates surface water productivity, and is driven by the East Asian summer monsoon, is the primary control of this decadal variability, while terrestrial inputs appear not influence significantly. Meanwhile the impacts of the Pacific Decadal Oscillation (PDO) and the El Nino and Southern Oscillation (ENSO) systems on seawater pH off eastern Hainan Island is likely limited. In contrast, the PDO is the main factor to influence the decadal seawater pH variability offshore the East Australia, while the mechanism controlling the decadal seawater pH variability in Guam is not clear yet. Meanwhile, The rate of decrease in seawater pH estimated from coral records are significantly different in different regions and over different time spans, which may reflect a combination of natural decadal variability in seawater pH and long-term variations. Therefore, understanding the mechanisms driving natural variability in seawater pH is important for improving estimates of ocean acidification rates driven by anthropogenic emissions.},
annote = {doi: 10.1002/2015JC011066},
author = {Wei, Gangjian and Wang, Zhibing and Ke, Ting and Liu, Ying and Deng, Wenfeng and Chen, Xuefei and Xu, Jifeng and Zeng, Ti and Xie, Luhua},
doi = {10.1002/2015JC011066},
issn = {2169-9275},
journal = {Journal of Geophysical Research: Oceans},
keywords = {boron isotope,coral,decadal variability,rate of ocean acidification,seawater pH},
month = {nov},
number = {11},
pages = {7166--7181},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Decadal variability in seawater pH in the West Pacific: Evidence from coral $\delta$11B records}},
url = {https://doi.org/10.1002/2015JC011066 http://doi.wiley.com/10.1002/2015JC011066 https://onlinelibrary.wiley.com/doi/abs/10.1002/2015JC011066},
volume = {120},
year = {2015}
}
@article{Welch2019,
abstract = {Abstract Tropical forests on upland soils are assumed to be a methane (CH4) sink and a weak source of nitrous oxide (N2O), but studies of wetland forests have demonstrated that tree stems can be a substantial source of CH4, and recent evidence from temperate woodlands suggests that tree stems can also emit N2O. Here, we measured CH4 and N2O fluxes from the soil and from tree stems in a semi-evergreen tropical forest on upland soil. To examine the influence of seasonality, soil abiotic conditions and substrate availability (litter inputs) on trace greenhouse gas (GHG) fluxes, we conducted our study during the transition from the dry to the wet season in a long-term litter manipulation experiment in Panama, Central America. Trace GHG fluxes were measured from individual stem bases of two common tree species and from soils beneath the same trees. Soil CH4 fluxes varied from uptake in the dry season to minor emissions in the wet season. Soil N2O fluxes were negligible during the dry season but increased markedly after the start of the wet season. By contrast, tree stem bases emitted CH4 and N2O throughout the study. Although we observed no clear effect of litter manipulation on trace GHG fluxes, tree species and litter treatments interacted to influence CH4 fluxes from stems and N2O fluxes from stems and soil, indicating complex relationships between tree species traits and decomposition processes that can influence trace GHG dynamics. Collectively, our results show that tropical trees can act as conduits for trace GHGs that most likely originate from deeper soil horizons, even when they are growing on upland soils. Coupled with the finding that the soils may be a weaker sink for CH4 than previously thought, our research highlights the need to reappraise trace gas budgets in tropical forests.},
author = {Welch, Bertie and Gauci, Vincent and Sayer, Emma J.},
doi = {10.1111/gcb.14498},
issn = {13652486},
journal = {Global Change Biology},
keywords = {leaf litter,methane,nitrous oxide,soil,trace greenhouse gases,tree stem emissions,upland tropical forest},
number = {1},
pages = {361--372},
title = {{Tree stem bases are sources of CH4 and N2O in a tropical forest on upland soil during the dry to wet season transition}},
volume = {25},
year = {2019}
}
@article{Welp2016,
abstract = {Abstract. Warmer temperatures and elevated atmospheric CO2 concentrations over the last several decades have been credited with increasing vegetation activity and photosynthetic uptake of CO2 from the atmosphere in the high northern latitude ecosystems: the boreal forest and arctic tundra. At the same time, soils in the region have been warming, permafrost is melting, fire frequency and severity are increasing, and some regions of the boreal forest are showing signs of stress due to drought or insect disturbance. The recent trends in net carbon balance of these ecosystems, across heterogeneous disturbance patterns, and the future implications of these changes are unclear. Here, we examine CO2 fluxes from northern boreal and tundra regions from 1985 to 2012, estimated from two atmospheric inversions (RIGC and Jena). Both used measured atmospheric CO2 concentrations and wind fields from interannually variable climate reanalysis. In the arctic zone, the latitude region above 60° N excluding Europe (10° W–63° E), neither inversion finds a significant long-term trend in annual CO2 balance. The boreal zone, the latitude region from approximately 50–60° N, again excluding Europe, showed a trend of 8–11 Tg C yr−2 over the common period of validity from 1986 to 2006, resulting in an annual CO2 sink in 2006 that was 170–230 Tg C yr−1 larger than in 1986. This trend appears to continue through 2012 in the Jena inversion as well. In both latitudinal zones, the seasonal amplitude of monthly CO2 fluxes increased due to increased uptake in summer, and in the arctic zone also due to increased fall CO2 release. These findings suggest that the boreal zone has been maintaining and likely increasing CO2 sink strength over this period, despite browning trends in some regions and changes in fire frequency and land use. Meanwhile, the arctic zone shows that increased summer CO2 uptake, consistent with strong greening trends, is offset by increased fall CO2 release, resulting in a net neutral trend in annual fluxes. The inversion fluxes from the arctic and boreal zones covering the permafrost regions showed no indication of a large-scale positive climate–carbon feedback caused by warming temperatures on high northern latitude terrestrial CO2 fluxes from 1985 to 2012.},
author = {Welp, Lisa R. and Patra, Prabir K. and R{\"{o}}denbeck, Christian and Nemani, Rama and Bi, Jian and Piper, Stephen C. and Keeling, Ralph F.},
doi = {10.5194/acp-16-9047-2016},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {jul},
number = {14},
pages = {9047--9066},
title = {{Increasing summer net CO2 uptake in high northern ecosystems inferred from atmospheric inversions and comparisons to remote-sensing NDVI}},
url = {https://acp.copernicus.org/articles/16/9047/2016/},
volume = {16},
year = {2016}
}
@article{Wenzel2016,
abstract = {Uncertainties in the response of vegetation to rising atmospheric CO2 concentrations1,2 contribute to the large spread in projections of future climate change3,4. Climate–carbon cycle models generally agree that elevated atmospheric CO2 concentrations will enhance terrestrial gross primary productivity (GPP). However, the magnitude of this CO2 fertilization effect varies from a 20 per cent to a 60 per cent increase in GPP for a doubling of atmospheric CO2 concentrations in model studies5,6,7. Here we demonstrate emergent constraints8,9,10,11 on large-scale CO2 fertilization using observed changes in the amplitude of the atmospheric CO2 seasonal cycle that are thought to be the result of increasing terrestrial GPP12,13,14. Our comparison of atmospheric CO2 measurements from Point Barrow in Alaska and Cape Kumukahi in Hawaii with historical simulations of the latest climate–carbon cycle models demonstrates that the increase in the amplitude of the CO2 seasonal cycle at both measurement sites is consistent with increasing annual mean GPP, driven in part by climate warming, but with differences in CO2 fertilization controlling the spread among the model trends. As a result, the relationship between the amplitude of the CO2 seasonal cycle and the magnitude of CO2 fertilization of GPP is almost linear across the entire ensemble of models. When combined with the observed trends in the seasonal CO2 amplitude, these relationships lead to consistent emergent constraints on the CO2 fertilization of GPP. Overall, we estimate a GPP increase of 37 ± 9 per cent for high-latitude ecosystems and 32 ± 9 per cent for extratropical ecosystems under a doubling of atmospheric CO2 concentrations on the basis of the Point Barrow and Cape Kumukahi records, respectively.},
author = {Wenzel, Sabrina and Cox, Peter M and Eyring, Veronika and Friedlingstein, Pierre},
doi = {10.1038/nature19772},
issn = {0028-0836},
journal = {Nature},
month = {oct},
number = {7626},
pages = {499--501},
publisher = {Macmillan Publishers Limited, part of Springer Nature. All rights reserved.},
title = {{Projected land photosynthesis constrained by changes in the seasonal cycle of atmospheric CO2}},
url = {http://dx.doi.org/10.1038/nature19772 http://www.nature.com/articles/nature19772},
volume = {538},
year = {2016}
}
@article{Wenzel2014,
abstract = {An emergent linear relationship between the long-term sensitivity of tropical land carbon storage to climate warming ($\gamma$LT) and the short-term sensitivity of atmospheric carbon dioxide (CO2) to interannual temperature variability ($\gamma$IAV) has previously been identified by Cox et al. (2013) across an ensemble of Earth System models (ESMs) participating in the Coupled Climate-Carbon Cycle Model Intercomparison Project (C4MIP). Here, we examine whether such a constraint also holds for a new set of eight ESMs participating in Phase 5 of the Coupled Model Intercomparison Project (CMIP5). A wide spread in tropical land carbon storage is found for the quadrupling of atmospheric CO2, which is of the order of 252 ± 112 GtC when carbon climate feedbacks are enabled. Correspondingly, the spread in $\gamma$LT is wide (-49 ± 40 GtC/K) and thus remains one of the key uncertainties in climate projections. A tight correlation is found between the long-term sensitivity of tropical land carbon and the short-term sensitivity of atmospheric CO2 ($\gamma$LT vs. $\gamma$IAV), which enables the projections to be constrained with observations. The observed short-term sensitivity of CO2 (-4.9 ± 0.9 GtC/yr/K) sharpens the range of $\gamma$LT -44 ± 14 GtC/K. Which overlaps with the probability density function (PDF) derived from the C4MIP models (-53 ± 17 GtC/K) by Cox et al. (2013), even though the lines relating $\gamma$LT and $\gamma$IAV differ in the two cases. Emergent constraints of this type provide a means to focus ESM evaluation against observations on the metrics most relevant to projections of future climate change.},
author = {Wenzel, Sabrina and Cox, Peter M. and Eyring, Veronika and Friedlingstein, Pierre},
doi = {10.1002/2013JG002591},
isbn = {2169-8961},
issn = {21698953},
journal = {Journal of Geophysical Research: Biogeosciences},
month = {may},
number = {5},
pages = {794--807},
title = {{Emergent constraints on climate–carbon cycle feedbacks in the CMIP5 Earth system models}},
url = {http://doi.wiley.com/10.1002/2013JG002591},
volume = {119},
year = {2014}
}
@article{Whitney2007,
author = {Whitney, Frank A and Freeland, Howard J and Robert, Marie},
doi = {10.1016/j.pocean.2007.08.007},
issn = {00796611},
journal = {Progress in Oceanography},
keywords = {Alaska Gyre,Dissolved oxygen,Hypoxia,Nitrates,Ocean Station P,Ocean stratification,Oxygen consumption,Subarctic Pacific Ocean,Water temperature},
month = {oct},
number = {2},
pages = {179--199},
title = {{Persistently declining oxygen levels in the interior waters of the eastern subarctic Pacific}},
url = {http://www.sciencedirect.com/science/article/pii/S0079661107001516 https://linkinghub.elsevier.com/retrieve/pii/S0079661107001516},
volume = {75},
year = {2007}
}
@article{Wieder2013,
abstract = {Society relies on Earth system models (ESMs) to project future climate and carbon (C) cycle feedbacks. However, the soil C response to climate change is highly uncertain in these models1,2 and they omit key biogeochemical mechanisms3,4,5. Specifically, the traditional approach in ESMs lacks direct microbial control over soil C dynamics6,7,8. Thus, we tested a new model that explicitly represents microbial mechanisms of soil C cycling on the global scale. Compared with traditional models, the microbial model simulates soil C pools that more closely match contemporary observations. It also projects a much wider range of soil C responses to climate change over the twenty-first century. Global soils accumulate C if microbial growth efficiency declines with warming in the microbial model. If growth efficiency adapts to warming, the microbial model projects large soil C losses. By comparison, traditional models project modest soil C losses with global warming. Microbes also change the soil response to increased C inputs, as might occur with CO2 or nutrient fertilization. In the microbial model, microbes consume these additional inputs; whereas in traditional models, additional inputs lead to C storage. Our results indicate that ESMs should simulate microbial physiology to more accurately project climate change feedbacks.},
author = {Wieder, William R and Bonan, Gordon B and Allison, Steven D},
doi = {10.1038/nclimate1951},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {oct},
number = {10},
pages = {909--912},
publisher = {Nature Publishing Group},
title = {{Global soil carbon projections are improved by modelling microbial processes}},
url = {http://dx.doi.org/10.1038/nclimate1951 http://www.nature.com/articles/nclimate1951},
volume = {3},
year = {2013}
}
@article{Wieder2018,
abstract = {Abstract Emerging insights into factors responsible for soil organic matter stabilization and decomposition are being applied in a variety of contexts, but new tools are needed to facilitate the understanding, evaluation, and improvement of soil biogeochemical theory and models at regional to global scales. To isolate the effects of model structural uncertainty on the global distribution of soil carbon stocks and turnover times we developed a soil biogeochemical testbed that forces three different soil models with consistent climate and plant productivity inputs. The models tested here include a first-order, microbial implicit approach (CASA-CNP), and two recently developed microbially explicit models that can be run at global scales (MIMICS and CORPSE). When forced with common environmental drivers, the soil models generated similar estimates of initial soil carbon stocks (roughly 1,400 Pg C globally, 0?100 cm), but each model shows a different functional relationship between mean annual temperature and inferred turnover times. Subsequently, the models made divergent projections about the fate of these soil carbon stocks over the 20th century, with models either gaining or losing over 20 Pg C globally between 1901 and 2010. Single-forcing experiments with changed inputs, temperature, and moisture suggest that uncertainty associated with freeze-thaw processes as well as soil textural effects on soil carbon stabilization were larger than direct temperature uncertainties among models. Finally, the models generated distinct projections about the timing and magnitude of seasonal heterotrophic respiration rates, again reflecting structural uncertainties that were related to environmental sensitivities and assumptions about physicochemical stabilization of soil organic matter. By providing a computationally tractable and numerically consistent framework to evaluate models we aim to better understand uncertainties among models and generate insights about factors regulating the turnover of soil organic matter.},
author = {Wieder, William R and Hartman, Melannie D and Sulman, Benjamin N and Wang, Ying-Ping and Koven, Charles D and Bonan, Gordon B},
doi = {10.1111/gcb.13979},
isbn = {1354-1013},
issn = {13541013},
journal = {Global Change Biology},
month = {apr},
number = {4},
pages = {1563--1579},
title = {{Carbon cycle confidence and uncertainty: Exploring variation among soil biogeochemical models}},
url = {http://doi.wiley.com/10.1111/gcb.13979},
volume = {24},
year = {2018}
}
@article{Wieder2015,
author = {Wieder, William R and Cleveland, Cory C and Smith, W Kolby and Todd-Brown, Katherine},
doi = {10.1038/ngeo2413},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {jun},
number = {6},
pages = {441--444},
publisher = {Nature Publishing Group},
title = {{Future productivity and carbon storage limited by terrestrial nutrient availability}},
url = {https://doi.org/10.1038/ngeo2413 http://10.0.4.14/ngeo2413 https://www.nature.com/articles/ngeo2413{\#}supplementary-information http://www.nature.com/articles/ngeo2413},
volume = {8},
year = {2015}
}
@article{Wieder2019,
author = {Wieder, William R. and Lawrence, David M. and Fisher, Rosie A. and Bonan, Gordon B. and Cheng, Susan J. and Goodale, Christine L. and Grandy, A. Stuart and Koven, Charles D. and Lombardozzi, Danica L. and Oleson, Keith W. and Thomas, R. Quinn},
doi = {10.1029/2018GB006141},
issn = {0886-6236},
journal = {Global Biogeochemical Cycles},
month = {oct},
number = {10},
pages = {1289--1309},
title = {{Beyond Static Benchmarking: Using Experimental Manipulations to Evaluate Land Model Assumptions}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GB006141},
volume = {33},
year = {2019}
}
@article{Wik2016,
abstract = {Review Article | Published: 04 January 2016 Climate-sensitive northern lakes and ponds are critical components of methane release Martin Wik, Ruth K. Varner, Katey Walter Anthony, Sally MacIntyre {\&} David Bastviken Nature Geoscience volume 9, pages 99–105 (2016) | Download Citation Abstract Lakes and ponds represent one of the largest natural sources of the greenhouse gas methane. By surface area, almost half of these waters are located in the boreal region and northwards. A synthesis of measurements of methane emissions from 733 lakes and ponds north of ∼50° N, combined with new inventories of inland waters, reveals that emissions from these high latitudes amount to around 16.5 Tg CH4 yr−1 (12.4 Tg CH4-C yr−1). This estimate — from lakes and ponds alone — is equivalent to roughly two-thirds of the inverse model calculation of all natural methane sources in the region. Thermokarst water bodies have received attention for their high emission rates, but we find that post-glacial lakes are a larger regional source due to their larger areal extent. Water body depth, sediment type and ecoclimatic region are also important in explaining variation in methane fluxes. Depending on whether warming and permafrost thaw cause expansion or contraction of lake and pond areal coverage, we estimate that annual water body emissions will increase by 20–54{\%} before the end of the century if ice-free seasons are extended by 20 days. We conclude that lakes and ponds are a dominant methane source at high northern latitudes.},
author = {Wik, Martin and Varner, Ruth K and Anthony, Katey Walter and MacIntyre, Sally and Bastviken, David},
doi = {10.1038/ngeo2578},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {feb},
number = {2},
pages = {99--105},
publisher = {Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.},
title = {{Climate-sensitive northern lakes and ponds are critical components of methane release}},
url = {http://dx.doi.org/10.1038/ngeo2578 http://www.nature.com/articles/ngeo2578},
volume = {9},
year = {2016}
}
@article{Wild10280,
abstract = {High-latitude permafrost and peat deposits contain a large reservoir of dormant carbon that, upon warming, may partly degrade to CO2 and CH4 at site and may partly enter rivers. Given the scale and heterogeneity of the Siberian Arctic, continent-wide patterns of thaw and remobilization have been challenging to constrain. This study combines a decade-long observational record of 14C in organic carbon of four large Siberian rivers with an extensive 14C source fingerprint database into a statistical model to provide a quantitative partitioning of the fraction of fluvially mobilized organic carbon that specifically stems from permafrost and peat deposits, and separately for dissolved and particulate vectors, across the Siberian Arctic, revealing distinct spatial and seasonal system patterns in carbon remobilization.Climate warming is expected to mobilize northern permafrost and peat organic carbon (PP-C), yet magnitudes and system specifics of even current releases are poorly constrained. While part of the PP-C will degrade at point of thaw to CO2 and CH4 to directly amplify global warming, another part will enter the fluvial network, potentially providing a window to observe large-scale PP-C remobilization patterns. Here, we employ a decade-long, high-temporal resolution record of 14C in dissolved and particulate organic carbon (DOC and POC, respectively) to deconvolute PP-C release in the large drainage basins of rivers across Siberia: Ob, Yenisey, Lena, and Kolyma. The 14C-constrained estimate of export specifically from PP-C corresponds to only 17 {\{}$\backslash$textpm{\}} 8{\%} of total fluvial organic carbon and serves as a benchmark for monitoring changes to fluvial PP-C remobilization in a warming Arctic. Whereas DOC was dominated by recent organic carbon and poorly traced PP-C (12 {\{}$\backslash$textpm{\}} 8{\%}), POC carried a much stronger signature of PP-C (63 {\{}$\backslash$textpm{\}} 10{\%}) and represents the best window to detect spatial and temporal dynamics of PP-C release. Distinct seasonal patterns suggest that while DOC primarily stems from gradual leaching of surface soils, POC reflects abrupt collapse of deeper deposits. Higher dissolved PP-C export by Ob and Yenisey aligns with discontinuous permafrost that facilitates leaching, whereas higher particulate PP-C export by Lena and Kolyma likely echoes the thermokarst-induced collapse of Pleistocene deposits. Quantitative 14C-based fingerprinting of fluvial organic carbon thus provides an opportunity to elucidate large-scale dynamics of PP-C remobilization in response to Arctic warming.},
author = {Wild, Birgit and Andersson, August and Br{\"{o}}der, Lisa and Vonk, Jorien and Hugelius, Gustaf and McClelland, James W and Song, Wenjun and Raymond, Peter A and Gustafsson, {\"{O}}rjan},
doi = {10.1073/pnas.1811797116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
number = {21},
pages = {10280--10285},
publisher = {National Academy of Sciences},
title = {{Rivers across the Siberian Arctic unearth the patterns of carbon release from thawing permafrost}},
url = {https://www.pnas.org/content/116/21/10280},
volume = {116},
year = {2019}
}
@article{Wilhelm2004,
author = {Wilhelm, W. W. and Johnson, J. M. F. and Hatfield, J. L. and Voorhees, W. B. and Linden, D. R.},
doi = {10.2134/agronj2004.1000},
issn = {1435-0645},
journal = {Agronomy Journal},
language = {en},
month = {jan},
number = {1},
pages = {1--17},
title = {{Crop and Soil Productivity Response to Corn Residue Removal}},
url = {https://dl.sciencesocieties.org/publications/aj/abstracts/96/1/1},
volume = {96},
year = {2004}
}
@article{acp-19-4257-2019,
author = {Wilkerson, J and Dobosy, R and Sayres, D S and Healy, C and Dumas, E and Baker, B and Anderson, J G},
doi = {10.5194/acp-19-4257-2019},
journal = {Atmospheric Chemistry and Physics},
number = {7},
pages = {4257--4268},
title = {{Permafrost nitrous oxide emissions observed on a landscape scale using the airborne eddy-covariance method}},
url = {https://www.atmos-chem-phys.net/19/4257/2019/},
volume = {19},
year = {2019}
}
@article{Williams2016a,
abstract = {Global surface warming projections have been empirically connected to carbon emissions via a climate index defined as the transient climate response to emissions (TCRE), revealing that surface warming is nearly proportional to carbon emissions. Here, we provide a theoretical framework to understand the TCRE including the effects of all radiative forcing in terms of the product of three terms: the dependence of surface warming on radiative forcing, the fractional radiative forcing contribution from atmospheric CO2 and the dependence of radiative forcing from atmospheric CO2 on cumulative carbon emissions. This framework is used to interpret the climate response over the next century for two Earth System Models of differing complexity, both containing a representation of the carbon cycle: an Earth System Model of Intermediate Complexity, configured as an idealised coupled atmosphere and ocean, and an Earth System Model, based on an atmosphere–ocean general circulation model and including non-CO2 radiative forcing and a land carbon cycle. Both Earth System Models simulate only a slight decrease in the TCRE over 2005–2100. This limited change in the TCRE is due to the ocean and terrestrial system acting to sequester both heat and carbon: carbon uptake acts to decrease the dependence of radiative forcing from CO2 on carbon emissions, which is partly compensated by changes in ocean heat uptake acting to increase the dependence of surface warming on radiative forcing. On decadal timescales, there are larger changes in the TCRE due to changes in ocean heat uptake and changes in non-CO2 radiative forcing, as represented by decadal changes in the dependences of surface warming on radiative forcing and the fractional radiative forcing contribution from atmospheric CO2. Our framework may be used to interpret the response of different climate models and used to provide traceability between climate models of differing complexity.},
author = {Williams, Richard G and Goodwin, Philip and Roussenov, Vassil M and Bopp, Laurent},
doi = {10.1088/1748-9326/11/1/015003},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jan},
number = {1},
pages = {015003},
publisher = {IOP Publishing},
title = {{A framework to understand the transient climate response to emissions}},
url = {http://iopscience.iop.org/article/10.1088/1748-9326/11/1/015003/meta http://stacks.iop.org/1748-9326/11/i=1/a=015003?key=crossref.dcd52e05a978c5ba2a42f3e3bdc24f75},
volume = {11},
year = {2016}
}
@article{Williams2015a,
abstract = {The Southern Ocean plays a major role in mediating the uptake, transport, and long-term storage of anthropogenic carbon dioxide (CO2) into the deep ocean. Examining the magnitude and spatial distribution of this oceanic carbon uptake is critical to understanding how the earth's carbon system will react to continued increases in this greenhouse gas. Here, we use the extended multiple linear regression technique to quantify the total and anthropogenic change in dissolved inorganic carbon (DIC) along the S04P and P16S CLIVAR/U.S. Global Ocean Carbon and Repeat Hydrography Program lines south of 67°S in the Pacific sector of the Southern Ocean between 1992 and 2011 using discrete bottle measurements from repeat occupations. Along the S04P section, which is located in the seasonal sea ice zone south of the Antarctic Circumpolar Current in the Pacific, the anthropogenic component of the DIC increase from 1992 to 2011 is mostly found in the Antarctic Surface Water (AASW, upper 100m), while the increase in DIC below the mixed layer in the Circumpolar Deep Water can be primarily attributed to either a slowdown in circulation or decreased ventilation of deeper, high CO2 waters. In the AASW we calculate an anthropogenic increase in DIC of 12–18$\mu$molkg−1 and an average storage rate of anthropogenic CO2 of 0.10±0.02molm−2yr−1 for this region compared to a global average of 0.5±0.2molm−2yr−1. In surface waters this anthropogenic CO2 uptake results in an average pH decrease of 0.0022±0.0004pH unitsyr−1, a 0.47±0.10{\%}yr−1 decrease in the saturation state of aragonite ($\Omega$Aragonite) and a 2.0±0.7myr−1 shoaling of the aragonite saturation horizons (calculated for the $\Omega$Aragonite=1.3 contour).},
author = {Williams, Nancy L and Feely, Richard A and Sabine, Christopher L and Dickson, Andrew G and Swift, James H and Talley, Lynne D and Russell, Joellen L},
doi = {10.1016/j.marchem.2015.06.015},
issn = {03044203},
journal = {Marine Chemistry},
keywords = {Anthropogenic carbon,Apparent oxygen utilization,Carbon dioxide,Carbonate chemistry,Decadal change,Dissolved inorganic carbon,Hydrography,Ocean acidification,Southern ocean,pH},
month = {aug},
pages = {147--160},
title = {{Quantifying anthropogenic carbon inventory changes in the Pacific sector of the Southern Ocean}},
url = {http://www.sciencedirect.com/science/article/pii/S0304420315001309 https://linkinghub.elsevier.com/retrieve/pii/S0304420315001309},
volume = {174},
year = {2015}
}
@article{Williams2017c,
author = {Williams, N. L. and Juranek, L. W. and Feely, R. A. and Johnson, K. S. and Sarmiento, J. L. and Talley, L. D. and Dickson, A. G. and Gray, A. R. and Wanninkhof, R. and Russell, J. L. and Riser, S. C. and Takeshita, Y.},
doi = {10.1002/2016GB005541},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {mar},
number = {3},
pages = {591--604},
title = {{Calculating surface ocean pCO2 from biogeochemical Argo floats equipped with pH: An uncertainty analysis}},
url = {http://doi.wiley.com/10.1002/2016GB005541},
volume = {31},
year = {2017}
}
@article{Williams2019a,
abstract = {Climate change involves a direct response of the climate system to forcing which is amplified or damped by feedbacks operating in the climate system. Carbon-cycle feedbacks alter the land and ocean carbon inventories and so act to reduce or enhance the increase in atmospheric CO 2 from carbon emissions. The prevailing framework for carbon-cycle feedbacks connect changes in land and ocean carbon inventories with a linear sum of dependencies on atmospheric CO 2 and surface temperature. Carbon-cycle responses and feedbacks provide competing contributions: the dominant effect is that increasing atmospheric CO 2 acts to enhance the land and ocean carbon stores, so providing a negative response and feedback to the original increase in atmospheric CO 2 , while rising surface temperature acts to reduce the land and ocean carbon stores, so providing a weaker positive feedback for atmospheric CO 2 . The carbon response and feedback of the land and ocean system may be expressed in terms of a combined carbon response and feedback parameter, $\lambda$ carbon in units of W m − 2 K − 1 , and is linearly related to the physical climate feedback parameter, $\lambda$ climate , revealing how carbon and climate responses and feedbacks are inter-connected. The magnitude and uncertainties in the carbon-cycle response and feedback parameter are comparable with the magnitude and uncertainties in the climate feedback parameter from clouds. Further mechanistic insight needs to be gained into how the carbon-cycle feedbacks are controlled for the land and ocean, particularly to separate often competing effects from changes in atmospheric CO 2 and climate forcing.},
author = {Williams, Richard G. and Katavouta, Anna and Goodwin, Philip},
doi = {10.1007/s40641-019-00144-9},
issn = {2198-6061},
journal = {Current Climate Change Reports},
month = {dec},
number = {4},
pages = {282--295},
title = {{Carbon-Cycle Feedbacks Operating in the Climate System}},
url = {http://link.springer.com/10.1007/s40641-019-00144-9},
volume = {5},
year = {2019}
}
@article{Williams2012,
abstract = {[1] Surface warming and steric sea level rise over the global ocean nearly linearly increase with cumulative carbon emissions for an atmosphere-ocean equilibrium, reached many centuries after emissions cease. Surface warming increases with cumulative emissions with a proportionality factor, $\Delta$Tsurface:2×CO{\textless}inf{\textgreater}2{\textless}/inf{\textgreater}/(I{\textless}inf{\textgreater}B{\textless}/inf{\textgreater} ln 2), ranging from 0.8 to 1.9 K (1000 PgC){\textless}sup{\textgreater}-1{\textless}/sup{\textgreater} for surface air temperature, depending on the climate sensitivity $\Delta$Tsurface:2×CO{\textless}inf{\textgreater}2{\textless}/inf{\textgreater} and the buffered carbon inventory I{\textless}inf{\textgreater}B{\textless}/inf{\textgreater}. Steric sea level rise similarly increases with cumulative emissions and depends on the climate sensitivity of the bulk ocean, ranging from 0.4 K to 2.7 K; a factor 0.4 ± 0.2 smaller than that for surface temperature based on diagnostics of two Earth System models. The implied steric sea level rise ranges from 0.7 m to 5 m for a cumulative emission of 5000 PgC, approached perhaps 500 years or more after emissions cease.},
author = {Williams, Richard G. and Goodwin, Philip and Ridgwell, Andy and Woodworth, Philip L.},
doi = {10.1029/2012GL052771},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {anthropogenic warming,carbon emissions,ocean warming,surface warming},
month = {oct},
number = {19},
pages = {L19715},
publisher = {Blackwell Publishing Ltd},
title = {{How warming and steric sea level rise relate to cumulative carbon emissions}},
url = {http://doi.wiley.com/10.1029/2012GL052771},
volume = {39},
year = {2012}
}
@article{Williams2020,
abstract = {The surface warming response to carbon emissions is diagnosed using a suite of Earth system models, 9 CMIP6 and 7 CMIP5, following an annual 1{\%} rise in atmospheric CO2 over 140 years. This surface warming response defines a climate metric, the Transient Climate Response to cumulative carbon Emissions (TCRE), which is important in estimating how much carbon may be emitted to avoid dangerous climate. The processes controlling these intermodel differences in the TCRE are revealed by defining the TCRE in terms of a product of three dependences: the surface warming dependence on radiative forcing (including the effects of physical climate feedbacks and planetary heat uptake), the radiative forcing dependence on changes in atmospheric carbon and the airborne fraction. Intermodel differences in the TCRE are mainly controlled by the thermal response involving the surface warming dependence on radiative forcing, which arise through large differences in physical climate feedbacks that are only partly compensated by smaller differences in ocean heat uptake. The other contributions to the TCRE from the radiative forcing and carbon responses are of comparable importance to the contribution from the thermal response on timescales of 50 years and longer for our subset of CMIP5 models and 100 years and longer for our subset of CMIP6 models. Hence, providing tighter constraints on how much carbon may be emitted based on the TCRE requires providing tighter bounds for estimates of the physical climate feedbacks, particularly from clouds, as well as to a lesser extent for the other contributions from the rate of ocean heat uptake, and the terrestrial and ocean cycling of carbon.},
author = {Williams, Richard G and Ceppi, Paulo and Katavouta, Anna},
doi = {10.1088/1748-9326/ab97c9},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {sep},
number = {9},
pages = {0940c1},
publisher = {IOP Publishing},
title = {{Controls of the transient climate response to emissions by physical feedbacks, heat uptake and carbon cycling}},
url = {https://doi.org/10.1088/1748-9326/ab97c9},
volume = {15},
year = {2020}
}
@article{Williams2017a,
author = {Williams, Richard G. and Roussenov, Vassil and Fr{\"{o}}licher, Thomas L. and Goodwin, Philip},
doi = {10.1002/2017GL075080},
issn = {00948276},
journal = {Geophysical Research Letters},
keywords = {carbon cycle,cumulative carbon emissions,global warming,ocean heat uptake,radiative forcing,stabilization of climate},
month = {oct},
number = {20},
pages = {10633--10642},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Drivers of continued surface warming after cessation of carbon emissions}},
url = {http://doi.wiley.com/10.1002/2017GL075080},
volume = {44},
year = {2017}
}
@article{Williams2017b,
abstract = {Climate projections reveal global-mean surface warming increasing nearly linearly with cumulative carbon emissions. The sensitivity of surface warming to carbon emissions is interpreted in terms of a product of three terms: the dependence of surface warming on radiative forcing, the fractional radiative forcing from CO 2 , and the dependence of radiative forcing from CO 2 on carbon emissions. Mechanistically each term varies, respectively, with climate sensitivity and ocean heat uptake, radiative forcing contributions, and ocean and terrestrial carbon uptake. The sensitivity of surface warming to fossil-fuel carbon emissions is examined using an ensemble of Earth system models, forced either by an annual increase in atmospheric CO 2 or by RCPs until year 2100. The sensitivity of surface warming to carbon emissions is controlled by a temporal decrease in the dependence of radiative forcing from CO 2 on carbon emissions, which is partly offset by a temporal increase in the dependence of surface warming on radiative forcing. The decrease in the dependence of radiative forcing from CO 2 is due to a decline in the ratio of the global ocean carbon undersaturation to carbon emissions, while the increase in the dependence of surface warming is due to a decline in the ratio of ocean heat uptake to radiative forcing. At the present time, there are large intermodel differences in the sensitivity in surface warming to carbon emissions, which are mainly due to uncertainties in the climate sensitivity and ocean heat uptake. These uncertainties undermine the ability to predict how much carbon may be emitted before reaching a warming target.},
author = {Williams, Richard G. and Roussenov, Vassil and Goodwin, Philip and Resplandy, Laure and Bopp, Laurent},
doi = {10.1175/JCLI-D-16-0468.1},
issn = {0894-8755},
journal = {Journal of Climate},
keywords = {Carbon dioxide,Climate change,Climate models,Climate sensitivity,Heating,Radiative forcing},
month = {dec},
number = {23},
pages = {9343--9363},
title = {{Sensitivity of Global Warming to Carbon Emissions: Effects of Heat and Carbon Uptake in a Suite of Earth System Models}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0468.1 https://journals.ametsoc.org/doi/10.1175/JCLI-D-16-0468.1},
volume = {30},
year = {2017}
}
@article{WILLIAMS2020s464,
abstract = {Addition of fats to the diets of ruminants has long been known to result in a reduction in enteric methane emissions. Tannins have also been used to reduce methane emissions but with mixed success. However, the effect of feeding fat in combination with tannin is unknown. Eight ruminally cannulated Holstein-Friesian cows were fed four diets in a double Latin-square, full crossover sequence. The treatments were 800 ml/day of water (CON), 800 g/day of cottonseed oil, 400 g/day of tannin, and 800 g/day of cottonseed oil and 400 g/day of tannin in combination (fat- and tannin-supplemented diet). Methane emissions were measured using open-circuit respiration chambers. Intake of basal diets was not different between treatments. Cows fed cottonseed oil had greater milk yield (34.9 kg/day) than those fed CON (32.3 kg/day), but the reduced concentration of milk fat meant there was no difference in energy-corrected milk between treatments. Methane yield was reduced when either cottonseed oil (14{\%}) or tannin (11{\%}) was added directly to the rumen, and their effect was additive when given in combination (20{\%} reduction). The mechanism of the anti-methanogenic effect remains unclear but both fat and tannin appear to cause a reduction in fermentation in general rather than cause a change in the type of fermentation.},
author = {Williams, S R O and Hannah, M C and Eckard, R J and Wales, W J and Moate, P J},
doi = {10.1017/S1751731120001032},
issn = {1751-7311},
journal = {Animal},
keywords = {anti-methanogen,cattle,cottonseed oil,respiration chamber,ruminant},
pages = {s464--s472},
title = {{Supplementing the diet of dairy cows with fat or tannin reduces methane yield, and additively when fed in combination}},
url = {https://www.sciencedirect.com/science/article/pii/S1751731120001032},
volume = {14},
year = {2020}
}
@techreport{WilliamsonP.&Bodle2016a,
address = {Montreal, QC, Canada},
author = {Williamson, P. and Bodle, R.},
isbn = {9789292256418},
pages = {158},
publisher = {Secretariat of the Convention on Biological Diversity},
title = {{Update on Climate Geoengineering in Relation to the Convention on Biological Diversity: Potential Impacts and Regulatory Framework}},
url = {https://www.cbd.int/doc/publications/cbd-ts-84-en.pdf},
year = {2016}
}
@article{https://doi.org/10.1111/gcb.13325,
abstract = {Abstract Drained peat soils are a significant source of greenhouse gas (GHG) emissions to the atmosphere. Rewetting these soils is considered an important climate change mitigation tool to reduce emissions and create suitable conditions for carbon sequestration. Long-term monitoring is essential to capture interannual variations in GHG emissions and associated environmental variables and to reduce the uncertainty linked with GHG emission factor calculations. In this study, we present GHG balances: carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) calculated for a 5-year period at a rewetted industrial cutaway peatland in Ireland (rewetted 7 years prior to the start of the study); and compare the results with an adjacent drained area (2-year data set), and with ten long-term data sets from intact (i.e. undrained) peatlands in temperate and boreal regions. In the rewetted site, CO2 exchange (or net ecosystem exchange (NEE)) was strongly influenced by ecosystem respiration (Reco) rather than gross primary production (GPP). CH4 emissions were related to soil temperature and either water table level or plant biomass. N2O emissions were not detected in either drained or rewetted sites. Rewetting reduced CO2 emissions in unvegetated areas by approximately 50{\%}. When upscaled to the ecosystem level, the emission factors (calculated as 5-year mean of annual balances) for the rewetted site were (±SD) −104 ± 80 g CO2-C m−2 yr−1 (i.e. CO2 sink) and 9 ± 2 g CH4-C m−2 yr−1 (i.e. CH4 source). Nearly a decade after rewetting, the GHG balance (100-year global warming potential) had reduced noticeably (i.e. less warming) in comparison with the drained site but was still higher than comparative intact sites. Our results indicate that rewetted sites may be more sensitive to interannual changes in weather conditions than their more resilient intact counterparts and may switch from an annual CO2 sink to a source if triggered by slightly drier conditions.},
author = {Wilson, David and Farrell, Catherine A and Fallon, David and Moser, Gerald and M{\"{u}}ller, Christoph and Renou-Wilson, Florence},
doi = {10.1111/gcb.13325},
journal = {Global Change Biology},
keywords = {carbon dioxide,climate change mitigation,interannual variation,methane,peat soils,rewetting},
number = {12},
pages = {4080--4095},
title = {{Multiyear greenhouse gas balances at a rewetted temperate peatland}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13325},
volume = {22},
year = {2016}
}
@article{WilsonD.BlainD.CouwenbergJ.EvansC.D.MurdiyarsoD.PageS.E.Renou-WilsonF.RieleyJ.O.SirinA.StrackM.&Tuittila2016,
author = {Wilson, D. and Blain, D. and Couwenberg, J. and Evans, C.D. and Murdiyarso, D. and Page, S.E. and Renou-Wilson, F. and Rieley, J.O. and Sirin, A. and Strack, M. and Tuittila, E.-S.},
doi = {10.19189/MaP.2016.OMB.222},
journal = {Mires and Peat},
number = {4},
pages = {1--28},
title = {{Greenhouse gas emission factors associated with rewetting of organic soils}},
volume = {17},
year = {2016}
}
@article{Winguth2012,
abstract = {The prominent global warming event at the Paleocene-Eocene boundary (55 Ma), referred to as the Paleocene-Eocene Thermal Maximum (PETM), was characterized by rapid temperature increase and changes in the global carbon cycle in {\textless}10,000 yr, and a major extinction of benthic foraminifera. We explore potential causes of this extinction in response to environmental changes linked to a mas- sive carbon injection by comparing sedimentary records with results from a comprehensive climate–carbon cycle model, and infer that an increase in oceanic vertical temperature gradients and stratifi ca- tion led to decreased productivity and oxygen depletion in the deep sea. Globally, productivity diminished particularly in the equatorial zone by weakening of the trades and hence upwelling, leading to a decline in food supply for benthic organisms. In contrast, near the Ross Sea, export of organic matter into the deep sea was enhanced due to increased near-surface mixing related to a positive salinity anomaly caused by a rise in wind-driven vertical mixing, contribut- ing to the depletion of the deep-sea oxygen concentration, combined with a sluggish deep-sea circulation. The extinction of deep-sea ben- thic foraminifera at the PETM thus was probably caused by multiple environmental changes, including decreased carbonate saturation and ocean acidifi cation, lowered oxygen levels, and a globally reduced food supply, all related to a massive carbon injection.},
author = {Winguth, A. M. E. and Thomas, Ellen and Winguth, Cornelia},
doi = {10.1130/G32529.1},
isbn = {0091-7613},
issn = {0091-7613},
journal = {Geology},
month = {mar},
number = {3},
pages = {263--266},
title = {{Global decline in ocean ventilation, oxygenation, and productivity during the Paleocene–Eocene Thermal Maximum: Implications for the benthic extinction}},
url = {https://pubs.geoscienceworld.org/geology/article/40/3/263-266/130840},
volume = {40},
year = {2012}
}
@article{Winiwarter2018,
abstract = {We describe a consistent framework developed to quantify current and future anthropogenic emissions of nitrous oxide and the available technical abatement options by source sector for 172 regions globally. About 65{\%} of the current emissions derive from agricultural soils, 8{\%} from waste, and 4{\%} from the chemical industry. Low-cost abatement options are available in industry, wastewater, and agriculture, where they are limited to large industrial farms. We estimate that by 2030, emissions can be reduced by about 6{\%} ±2{\%} applying abatement options at a cost lower than 10 €/t CO2-eq. The largest abatement potential at higher marginal costs is available from agricultural soils, employing precision fertilizer application technology as well as chemical treatment of fertilizers to suppress conversion processes in soil (nitrification inhibitors). At marginal costs of up to 100 €/t CO2-eq, about 18{\%} ±6{\%} of baseline emissions can be removed and when considering all available options, the global abatement potential increases to about 26{\%} ±9{\%}. Due to expected future increase in activities driving nitrous oxide emissions, the limited technical abatement potential available means that even at full implementation of reduction measures by 2030, global emissions can be at most stabilized at the pre-2010 level. In order to achieve deeper reductions in emissions, considerable technological development will be required as well as non-technical options like adjusting human diets towards moderate animal protein consumption.},
author = {Winiwarter, Wilfried and H{\"{o}}glund-Isaksson, Lena and Klimont, Zbigniew and Sch{\"{o}}pp, Wolfgang and Amann, Markus},
doi = {10.1088/1748-9326/aa9ec9},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {jan},
number = {1},
pages = {014011},
publisher = {IOP Publishing},
title = {{Technical opportunities to reduce global anthropogenic emissions of nitrous oxide}},
url = {http://stacks.iop.org/1748-9326/13/i=1/a=014011?key=crossref.455b1c5e08bb0ad4726002f0b5b62762},
volume = {13},
year = {2018}
}
@article{Winkler2019b,
abstract = {Most Earth system models agree that land will continue to store carbon due to the physiological effects of rising CO 2 concentration and climatic changes favoring plant growth in temperature-limited regions. But they largely disagree on the amount of carbon uptake. The historical CO 2 increase has resulted in enhanced photosynthetic carbon fixation (Gross Primary Production, GPP), as can be evidenced from atmospheric CO 2 concentration and satellite leaf area index measurements. Here, we use leaf area sensitivity to ambient CO 2 from the past 36 years of satellite measurements to obtain an Emergent Constraint (EC) estimate of GPP enhancement in the northern high latitudes at two-times the pre-industrial CO 2 concentration (3.4 ± 0.2 Pg C yr −1 ). We derive three independent comparable estimates from CO 2 measurements and atmospheric inversions. Our EC estimate is 60{\%} larger than the conventionally used multi-model average (44{\%} higher at the global scale). This suggests that most models largely underestimate photosynthetic carbon fixation and therefore likely overestimate future atmospheric CO 2 abundance and ensuing climate change, though not proportionately.},
author = {Winkler, Alexander J. and Myneni, Ranga B. and Alexandrov, Georgii A. and Brovkin, Victor},
doi = {10.1038/s41467-019-08633-z},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {885},
title = {{Earth system models underestimate carbon fixation by plants in the high latitudes}},
url = {http://www.nature.com/articles/s41467-019-08633-z},
volume = {10},
year = {2019}
}
@article{Winterfeld2018,
author = {Winterfeld, Maria and Mollenhauer, Gesine and Dummann, Wolf and K{\"{o}}hler, Peter and Lembke-Jene, Lester and Meyer, Vera D. and Hefter, Jens and McIntyre, Cameron and Wacker, Lukas and Kokfelt, Ulla and Tiedemann, Ralf},
doi = {10.1038/s41467-018-06080-w},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {3666},
title = {{Deglacial mobilization of pre-aged terrestrial carbon from degrading permafrost}},
url = {http://www.nature.com/articles/s41467-018-06080-w},
volume = {9},
year = {2018}
}
@article{Wolf2016,
abstract = {The global terrestrial carbon sink offsets one-third of the world's fossil fuel emissions, but the strength of this sink is highly sensitive to large-scale extreme events. In 2012, the contiguous United States experienced exceptionally warm temperatures and the most severe drought since the Dust Bowl era of the 1930s, resulting in substantial economic damage. It is crucial to understand the dynamics of such events because warmer temperatures and a higher prevalence of drought are projected in a changing climate. Here, we combine an extensive network of direct ecosystem flux measurements with satellite remote sensing and atmospheric inverse modeling to quantify the impact of the warmer spring and summer drought on biosphereatmosphere carbon and water exchange in 2012. We consistently find that earlier vegetation activity increased spring carbon uptake and compensated for the reduced uptake during the summer drought, which mitigated the impact on net annual carbon uptake. The early phenological development in the Eastern Temperate Forests played a major role for the continental-scale carbon balance in 2012. The warm spring also depleted soil water resources earlier, and thus exacerbated water limitations during summer. Our results show that the detrimental effects of severe summer drought on ecosystem carbon storage can be mitigated by warming-induced increases in spring carbon uptake. However, the results also suggest that the positive carbon cycle effect of warm spring enhances water limitations and can increase summer heating through biosphere-atmosphere feedbacks.},
author = {Wolf, Sebastian and Keenan, Trevor F. and Fisher, Joshua B. and Baldocchi, Dennis D. and Desai, Ankur R. and Richardson, Andrew D. and Scott, Russell L. and Law, Beverly E. and Litvak, Marcy E. and Brunsell, Nathaniel A. and Peters, Wouter and {Van Der Laan-Luijkx}, Ingrid T.},
doi = {10.1073/pnas.1519620113},
issn = {10916490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Biosphere Atmosphere feedbacks,Carbon uptake,Climate anomalies,Ecosystem fluxes,Eddy covariance},
number = {21},
pages = {5880--5885},
pmid = {27114518},
title = {{Warm spring reduced carbon cycle impact of the 2012 US summer drought}},
volume = {113},
year = {2016}
}
@article{Wolter1998,
author = {Wolter, Klaus and Timlin, Michael S.},
doi = {10.1002/j.1477-8696.1998.tb06408.x},
issn = {00431656},
journal = {Weather},
month = {sep},
number = {9},
pages = {315--324},
title = {{Measuring the strength of ENSO events: How does 1997/98 rank?}},
url = {http://doi.wiley.com/10.1002/j.1477-8696.1998.tb06408.x},
volume = {53},
year = {1998}
}
@article{Woolf2010a,
abstract = {Production of biochar (the carbon (C)-rich solid formed by pyrolysis of biomass) and its storage in soils have been suggested as a means of abating climate change by sequestering carbon, while simultaneously providing energy and increasing crop yields. Substantial uncertainties exist, however, regarding the impact, capacity and sustainability of biochar at the global level. In this paper we estimate the maximum sustainable technical potential of biochar to mitigate climate change. Annual net emissions of carbon dioxide (CO2), methane and nitrous oxide could be reduced by a maximum of 1.8 Pg CO2-C equivalent (CO2-Ce) per year (12{\%} of current anthropogenic CO2-Ce emissions; 1 Pg=1 Gt), and total net emissions over the course of a century by 130 Pg CO2-Ce, without endangering food security, habitat or soil conservation. Biochar has a larger climate-change mitigation potential than combustion of the same sustainably procured biomass for bioenergy, except when fertile soils are amended while coal is the fuel being offset. View full text},
author = {Woolf, Dominic and Amonette, James E. and Street-Perrott, F. Alayne and Lehmann, Johannes and Joseph, Stephen},
doi = {10.1038/ncomms1053},
issn = {2041-1723},
journal = {Nature Communications},
language = {en},
month = {dec},
number = {1},
pages = {56},
title = {{Sustainable biochar to mitigate global climate change}},
url = {http://www.nature.com/articles/ncomms1053 http://dx.doi.org/10.1038/ncomms1053 http://www.nature.com/doifinder/10.1038/ncomms1053},
volume = {1},
year = {2010}
}
@article{Woosley2016,
abstract = {Abstract The extended multilinear regression method is used to determine the uptake and storage of anthropogenic carbon in the Atlantic Ocean based on repeat occupations of four cruises from 1989 to 2014 (A16, A20, A22, and A10), with an emphasis on the 2003?2014 period. The results show a significant increase in basin-wide anthropogenic carbon storage in the North Atlantic, which absorbed 4.4?±?0.9?Pg?C?decade?1 from 2003 to 2014 compared to 1.9?±?0.4?Pg?C?decade?1 for the 1989?2003 period. This decadal variability is attributed to changing ventilation patterns associated with the North Atlantic Oscillation and increasing release of anthropogenic carbon into the atmosphere. There are small changes in the uptake rate of CO2 in the South Atlantic for these time periods (3.7?±?0.8?Pg?C?decade?1 versus 3.2?±?0.7?Pg?C?decade?1). Several eddies are identified containing {\~{}}20{\%} more anthropogenic carbon than the surrounding waters in the South Atlantic demonstrating the importance of eddies in transporting anthropogenic carbon. The uptake of carbon results in a decrease in pH of {\~{}}0.0021?±?0.0007?year?1 for surface waters during the last 10?years, in line with the atmospheric increase in CO2.},
annote = {doi: 10.1002/2015GB005248},
author = {Woosley, Ryan J and Millero, Frank J and Wanninkhof, Rik},
doi = {10.1002/2015GB005248},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
keywords = {Atlantic Ocean,anthropogenic carbon,ocean acidification},
month = {jan},
number = {1},
pages = {70--90},
publisher = {Wiley-Blackwell},
title = {{Rapid anthropogenic changes in CO2 and pH in the Atlantic Ocean: 2003–2014}},
url = {https://doi.org/10.1002/2015GB005248 http://doi.wiley.com/10.1002/2015GB005248},
volume = {30},
year = {2016}
}
@article{Worden2017,
abstract = {Several viable but conflicting explanations have been proposed to explain the recent {\~{}}8 p.p.b. per year increase in atmospheric methane after 2006, equivalent to net emissions increase of {\~{}}25 Tg CH4 per year. A concurrent increase in atmospheric ethane implicates a fossil source; a concurrent decrease in the heavy isotope content of methane points toward a biogenic source, while other studies propose a decrease in the chemical sink (OH). Here we show that biomass burning emissions of methane decreased by 3.7 (±1.4) Tg CH4 per year from the 2001–2007 to the 2008–2014 time periods using satellite measurements of CO and CH4, nearly twice the decrease expected from prior estimates. After updating both the total and isotopic budgets for atmospheric methane with these revised biomass burning emissions (and assuming no change to the chemical sink), we find that fossil fuels contribute between 12–19 Tg CH4 per year to the recent atmospheric methane increase, thus reconciling the isotopic- and ethane-based results.},
author = {Worden, John R. and Bloom, A Anthony and Pandey, Sudhanshu and Jiang, Zhe and Worden, Helen M and Walker, Thomas W and Houweling, Sander and R{\"{o}}ckmann, Thomas},
doi = {10.1038/s41467-017-02246-0},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {2227},
title = {{Reduced biomass burning emissions reconcile conflicting estimates of the post-2006 atmospheric methane budget}},
url = {https://doi.org/10.1038/s41467-017-02246-0 http://www.nature.com/articles/s41467-017-02246-0},
volume = {8},
year = {2017}
}
@article{Wu2018d,
abstract = {Increasing atmospheric CO2 from man-made climate change is reducing surface ocean pH. Due to limited instrumental measurements and historical pH records in the world's oceans, seawater pH variability at the decadal and centennial scale remains largely unknown and requires documentation. Here we present evidence of striking secular trends of decreasing pH since the late nineteenth century with pronounced interannual to decadal–interdecadal pH variability in the South Pacific Ocean from 1689 to 2011 CE. High-amplitude oceanic pH changes, likely related to atmospheric CO2 uptake and seawater dissolved inorganic carbon fluctuations, reveal a coupled relationship to sea surface temperature variations and highlight the marked influence of El Ni{\~{n}}o/Southern Oscillation and Interdecadal Pacific Oscillation. We suggest changing surface winds strength and zonal advection processes as the main drivers responsible for regional pH variability up to 1881 CE, followed by the prominent role of anthropogenic CO2 in accelerating the process of ocean acidification.},
author = {Wu, Henry C. and Dissard, Delphine and Douville, Eric and Blamart, Dominique and Bordier, Louise and Tribollet, Aline and {Le Cornec}, Florence and Pons-Branchu, Edwige and Dapoigny, Arnaud and Lazareth, Claire E.},
doi = {10.1038/s41467-018-04922-1},
issn = {2041-1723},
journal = {Nature Communications},
keywords = {Biogeochemistry,Climate change,Climate sciences,Ocean sciences,Palaeoceanography},
month = {dec},
number = {1},
pages = {2543},
publisher = {Nature Publishing Group},
title = {{Surface ocean pH variations since 1689 CE and recent ocean acidification in the tropical South Pacific}},
url = {http://www.nature.com/articles/s41467-018-04922-1},
volume = {9},
year = {2018}
}
@article{Wu2019,
author = {Wu, Yingxu and Hain, Mathis P. and Humphreys, Matthew P. and Hartman, Sue and Tyrrell, Toby},
doi = {10.5194/bg-16-2661-2019},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jul},
number = {13},
pages = {2661--2681},
publisher = {Copernicus GmbH},
title = {{What drives the latitudinal gradient in open-ocean surface dissolved inorganic carbon concentration?}},
url = {https://bg.copernicus.org/articles/16/2661/2019/},
volume = {16},
year = {2019}
}
@article{WU2018199,
abstract = {Afforestation plays an important role in regulating the methane (CH4) exchange between soil and atmosphere. However, it is not fully understood how afforestation affects soil CH4 flux and the carbon isotopic signature of CH4. We conducted a year-long measurement of CH4 in afforested land (woodland and shrubland) and the adjacent cropland using the static chamber-gas chromatographic technique in the Danjiangkou Reservoir of central China. The soil exclusively functioned as a sink for atmospheric CH4 through the entire study period across land use types. Land use types significantly impacted the CH4 uptake rate with the largest average CH4 uptake rate in the shrubland (37.22 $\mu$g m−2{\textperiodcentered}h−1), followed by the woodland (27.75 $\mu$g m−2{\textperiodcentered}h−1) and the cropland (14.34 $\mu$g m−2{\textperiodcentered}h−1). The mean annual CH4 uptake rates increased in the shrubland by 186.3{\%} and the woodland by 93.5{\%}, compared to the cropland. The isotope fractionation factor ($\alpha$soil) was lower in the woodland and shrubland, compared to the cropland. The CH4 uptake rates and $\alpha$soil exhibited similar seasonal patterns among land use types, with a higher CH4 uptake rates and lower $\alpha$soil in spring and summer compared to other seasons. The CH4 uptake rates were positively related to microbial biomass carbon (MBC) and labile C. Meanwhile, the CH4 uptake rate was exponentially correlated with inorganic nitrogen (N) concentration, suggesting the high inorganic N concentration in the cropland possibly inhibited the CH4 uptake rate. In afforested land, CH4 uptake rates positively correlated with soil temperature and negatively correlated with the C: N ratio. The $\alpha$soil was negatively related to soil temperature, whereas the $\delta$13C values of CH4 remaining in the chambers were positively related to the $\delta$13C values of soil organic carbon (SOC) and MBC. Our results suggest that the change in soil properties (i.e. high SOC and MBC, low C:N ratio and low inorganic N) following afforestation is a critical control on enhanced CH4 uptake capacity, while a lower $\alpha$soil further provides evidence for a high CH4 uptake rate in afforested lands.},
author = {Wu, Junjun and Li, Qianxi and Chen, Jingwen and Lei, Yao and Zhang, Qian and Yang, Fan and Zhang, Dandan and Zhang, Quanfa and Cheng, Xiaoli},
doi = {https://doi.org/10.1016/j.soilbio.2017.12.017},
issn = {0038-0717},
journal = {Soil Biology and Biochemistry},
keywords = {Afforestation,Carbon isotope,Methane uptake rate,Soil properties},
pages = {199--206},
title = {{Afforestation enhanced soil CH4 uptake rate in subtropical China: Evidence from carbon stable isotope experiments}},
url = {http://www.sciencedirect.com/science/article/pii/S0038071717306971},
volume = {118},
year = {2018}
}
@article{Xia2016,
abstract = {Abstract. Stratospheric sulfate geoengineering could impact the terrestrial carbon cycle by enhancing the carbon sink. With an 8Tgyr−1 injection of SO2 to produce a stratospheric aerosol cloud to balance anthropogenic radiative forcing from the Representative Concentration Pathway 6.0 (RCP6.0) scenario, we conducted climate model simulations with the Community Earth System Model – the Community Atmospheric Model 4 fully coupled to tropospheric and stratospheric chemistry (CAM4–chem). During the geoengineering period, as compared to RCP6.0, land-averaged downward visible (300–700nm) diffuse radiation increased 3.2Wm−2 (11{\%}). The enhanced diffuse radiation combined with the cooling increased plant photosynthesis by 0.07±0.02µmolCm−2s−1, which could contribute to an additional 3.8±1.1GtCyr−1 global gross primary productivity without explicit nutrient limitation. This increase could potentially increase the land carbon sink. Suppressed plant and soil respiration due to the cooling would reduce natural land carbon emission and therefore further enhance the terrestrial carbon sink during the geoengineering period. This potentially beneficial impact of stratospheric sulfate geoengineering would need to be balanced by a large number of potential risks in any future decisions about the implementation of geoengineering.},
author = {Xia, L. and Robock, A. and Tilmes, S. and {Neely III}, R. R.},
doi = {10.5194/acp-16-1479-2016},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {feb},
number = {3},
pages = {1479--1489},
title = {{Stratospheric sulfate geoengineering could enhance the terrestrial photosynthesis rate}},
url = {https://www.atmos-chem-phys.net/16/1479/2016/},
volume = {16},
year = {2016}
}
@article{Xia2014,
abstract = {Geoengineering via solar radiation management could affect agricultural productivity due to changes in temperature, precipitation, and solar radiation. To study rice and maize production changes in China, we used results from 10 climate models participating in the Geoengineering Model Intercomparison Project (GeoMIP) G2 scenario to force the Decision Support System for Agrotechnology Transfer (DSSAT) crop model. G2 prescribes an insolation reduction to balance a 1{\%} a 
 1 increase in CO 2 concentration (1pctCO2) for 50 years. We fi rst evaluated the DSSAT model using 30 years (1978 – 2007) of daily observed weather records and agriculture practices for 25 major agriculture provinces in China and compared the results to observations of yield. We then created three sets of climate forcing for 42 locations in China for DSSAT from each climate model experiment: (1) 1pctCO2, (2) G2, and (3) G2 with constant CO 2 concentration (409 ppm) and compared the resulting agricultural respons es. In the DSSAT simulations: (1) Without changing management practices, the combined effect of simulated climate changes due to geoengineering and CO 2 fertilization during the last 15 years of solar redu ction would change rice production in China by 
 3.0 ± 4.0 megaton (Mt) (2.4 ± 4.0{\%}) as compared with 1pctCO2 and increase Chinese maize production by 18.1 ± 6.0 Mt (13.9 ± 5.9{\%}). (2) The termination of g eoengineering shows negligible impacts on rice production but a 19.6 Mt (11.9{\%}) reduction of maize production as compared to the last 15 years of geoengineering. (3) The CO 2 fertilization effect compensates for th e deleterious impacts of changes in temperature, precipitation, and solar radiation due to geoengineering on rice pro duction, increasing rice production by 8.6 Mt. The elevated CO 2 concentration enhances maize production in G2, contributing 7.7 Mt (42.4{\%}) to the total increase. Using the DSSAT crop model, virtually all of the climate models agree on the sign of the responses, even though the spread across models is large. This suggests that solar radiation management would have little impact on rice production in China but could increase maize production.},
author = {Xia, Lili and Robock, Alan and Cole, Jason and Curry, Charles L. and Ji, Duoying and Jones, Andy and Kravitz, Ben and Moore, John C. and Muri, Helene and Niemeier, Ulrike and Singh, Balwinder and Tilmes, Simone and Watanabe, Shingo and Yoon, Jin-Ho},
doi = {10.1002/2013JD020630},
isbn = {2169-8996},
issn = {2169897X},
journal = {Journal of Geophysical Research: Atmospheres},
month = {jul},
number = {14},
pages = {8695--8711},
title = {{Solar radiation management impacts on agriculture in China: A case study in the Geoengineering Model Intercomparison Project (GeoMIP)}},
url = {http://doi.wiley.com/10.1002/2013JD020630},
volume = {119},
year = {2014}
}
@article{Xia2017,
author = {Xia, L and Nowack, P J and Tilmes, S and Robock, A},
doi = {10.5194/acp-17-11913-2017},
journal = {Atmospheric Chemistry and Physics},
number = {19},
pages = {11913--11928},
title = {{Impacts of stratospheric sulfate geoengineering on tropospheric ozone}},
volume = {17},
year = {2017}
}
@article{Xu2016a,
abstract = {Stomata control the flow of gases between plants and the atmosphere. This review is centered on stomatal responses to elevated CO2 concentration and considers other key environmental factors and underlying mechanisms at multiple levels. First, an outline of general responses in stomatal conductance under elevated CO2 is presented. Second, stomatal density response, its development, and the trade-off with leaf growth under elevated CO2 conditions are depicted. Third, the molecular mechanism regulating guard cell movement at elevated CO2 is suggested. Finally, the interactive effects of elevated CO2with other factors critical to stomatal behavior are reviewed. It may be useful to better understand how stomata respond to elevated CO2 levels while considering other key environmental factors and mechanisms, including molecular mechanism, biochemical processes, and ecophysiological regulation. This understanding may provide profound new insights into how plants cope with climate change.},
author = {Xu, Zhenzhu and Jiang, Yanling and Jia, Bingrui and Zhou, Guangsheng},
doi = {10.3389/fpls.2016.00657},
issn = {1664462X},
journal = {Frontiers in Plant Science},
keywords = {Drought,Elevated CO2,Global warming,Guard cell,Mesophyll-driven signals,Photosynthesis,Regulation mechanism,Stomatal behavior},
number = {MAY2016},
pages = {1--15},
title = {{Elevated-CO2 response of stomata and its dependence on environmental factors}},
volume = {7},
year = {2016}
}
@article{doi:10.1111/j.1469-8137.2012.04269.x,
abstract = {Summary Ecosystem nitrous oxide (N2O) emissions respond to changes in climate and CO2 concentration as well as anthropogenic nitrogen (N) enhancements. Here, we aimed to quantify the responses of natural ecosystem N2O emissions to multiple environmental drivers using a process-based global vegetation model (DyN-LPJ). We checked that modelled annual N2O emissions from nonagricultural ecosystems could reproduce field measurements worldwide, and experimentally observed responses to step changes in environmental factors. We then simulated global N2O emissions throughout the 20th century and analysed the effects of environmental changes. The model reproduced well the global pattern of N2O emissions and the observed responses of N cycle components to changes in environmental factors. Simulated 20th century global decadal-average soil emissions were c. 8.2–9.5 Tg N yr−1 (or 8.3–10.3 Tg N yr−1 with N deposition). Warming and N deposition contributed 0.85 ± 0.41 and 0.80 ± 0.14 Tg N yr−1, respectively, to an overall upward trend. Rising CO2 also contributed, in part, through a positive interaction with warming. The modelled temperature dependence of N2O emission (c. 1 Tg N yr−1 K−1) implies a positive climate feedback which, over the lifetime of N2O (114 yr), could become as important as the climate–carbon cycle feedback caused by soil CO2 release.},
annote = {added by A.Eliseev 22.01.2019},
author = {Xu‐Ri and Prentice, I Colin and Spahni, Renato and Niu, Hai Shan},
doi = {10.1111/j.1469-8137.2012.04269.x},
issn = {0028-646X},
journal = {New Phytologist},
keywords = {CO2,climate feedback,dynamic global vegetation model,greenhouse gas,nitrogen cycle,nitrous oxide (N2O)},
month = {oct},
number = {2},
pages = {472--488},
title = {{Modelling terrestrial nitrous oxide emissions and implications for climate feedback}},
url = {https://nph.onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-8137.2012.04269.x https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-8137.2012.04269.x},
volume = {196},
year = {2012}
}
@article{Yamagata2018,
abstract = {Negative emission technologies such as bioenergy with carbon capture and storage (BECCS) are regarded as an option to achieve the climatic target of the Paris Agreement. However, our understanding of the realistic sustainable feasibility of the global lands for BECCS remains uncertain. In this study, we assess the impact of BECCS deployment scenarios on the land systems including land use, water resources, and ecosystem services. Specifically, we assess three land-use scenarios to achieve the total amount of 3.3 GtC year−1 (annual negative emission level required for IPCC-RCP 2.6) emission reduction by growing bioenergy crops which requires huge use of global agricultural and forest lands and water. Our study shows that (1) vast conversion of food cropland into rainfed bio-crop cultivation yields a considerable loss of food production that may not be tolerable considering the population increase in the future. (2) When irrigation is applied to bio-crop production, the bioenergy crop productivity is enhanced. This suppresses the necessary area for bio-crop production to half, and saves the land for agricultural productions. However, water consumption is doubled and this may exacerbate global water stress. (3) If conversion of forest land for bioenergy crop cultivation is allowed without protecting the natural forests, large areas of tropical forest could be used for bioenergy crop production. Forest biomass and soil carbon stocks are reduced, implying degradation of the climate regulation and other ecosystem services. These results suggest that without a careful consideration of the land use for bioenergy crop production, a large-scale implementation of BECCS could negatively impact food, water and ecosystem services that are supporting fundamental human sustainability.},
author = {Yamagata, Yoshiki and Hanasaki, Naota and Ito, Akihiko and Kinoshita, Tsuguki and Murakami, Daisuke and Zhou, Qian},
doi = {10.1007/s11625-017-0522-5},
isbn = {0123456789},
issn = {18624057},
journal = {Sustainability Science},
keywords = {BECCS,Ecosystem service,Land use,Sustainability,Water resources},
number = {2},
pages = {301--313},
publisher = {Springer Japan},
title = {{Estimating water–food–ecosystem trade-offs for the global negative emission scenario (IPCC-RCP2.6)}},
url = {http://dx.doi.org/10.1007/s11625-017-0522-5},
volume = {13},
year = {2018}
}
@article{Yamamoto2019,
abstract = {Abstract. Increased accumulation of respired carbon in the deep ocean associated with enhanced efficiency of the biological carbon pump is thought to be a key mechanism of glacial CO2 drawdown. Despite greater oxygen solubility due to seawater cooling, recent quantitative and qualitative proxy data show glacial deep-water deoxygenation, reflecting increased respired carbon accumulation. However, the mechanisms of deep-water deoxygenation and contribution from the biological pump to glacial CO2 drawdown have remained unclear. In this study, we report the significance of iron fertilization from glaciogenic dust in glacial CO2 decrease and deep-water deoxygenation using our numerical simulation, which successfully reproduces the magnitude and large-scale pattern of the observed oxygen changes from the present to the Last Glacial Maximum. Sensitivity experiments show that physical changes contribute to only one-half of all glacial deep deoxygenation, whereas the other one-half is driven by iron fertilization and an increase in the whole ocean nutrient inventory. We find that iron input from glaciogenic dust with higher iron solubility is the most significant factor in enhancing the biological pump and deep-water deoxygenation. Glacial deep-water deoxygenation expands the hypoxic waters in the deep Pacific and Indian oceans. The simulated global volume of hypoxic waters is nearly double the present value, suggesting that glacial deep water was a more severe environment for benthic animals than that of the modern oceans. Our model underestimates the deoxygenation in the deep Southern Ocean because of enhanced ventilation. The model–proxy comparison of oxygen change suggests that a stratified Southern Ocean is required for reproducing the oxygen decrease in the deep Southern Ocean. Iron fertilization and a global nutrient increase contribute to a decrease in glacial CO2 of more than 30 ppm, which is supported by the model–proxy agreement of oxygen change. Our findings confirm the significance of the biological pump in glacial CO2 drawdown and deoxygenation.},
author = {Yamamoto, Akitomo and Abe-Ouchi, Ayako and Ohgaito, Rumi and Ito, Akinori and Oka, Akira},
doi = {10.5194/cp-15-981-2019},
issn = {1814-9332},
journal = {Climate of the Past},
month = {jun},
number = {3},
pages = {981--996},
title = {{Glacial CO2 decrease and deep-water deoxygenation by iron fertilization from glaciogenic dust}},
url = {https://www.clim-past.net/15/981/2019/},
volume = {15},
year = {2019}
}
@article{Yamamoto2012,
abstract = {Abstract. The largest pH decline and widespread undersaturation with respect to aragonite in this century due to uptake of anthropogenic carbon dioxide in the Arctic Ocean have been projected. The reductions in pH and aragonite saturation state in the Arctic Ocean have been caused by the melting of sea ice as well as by an increase in the concentration of atmospheric carbon dioxide. Therefore, future projections of pH and aragonite saturation in the Arctic Ocean will be affected by how rapidly the reduction in sea ice occurs. The observed recent Arctic sea-ice loss has been more rapid than projected by many of the climate models that contributed to the Intergovernmental Panel on Climate Change Fourth Assessment Report. In this study, the impact of sea-ice reduction rate on projected pH and aragonite saturation state in the Arctic surface waters was investigated. Reductions in pH and aragonite saturation were calculated from the outputs of two versions of an Earth system model with different sea-ice reduction rates under similar CO2 emission scenarios. The newer model version projects that Arctic summer ice-free condition will be achieved by the year 2040, and the older version predicts ice-free condition by 2090. The Arctic surface water was projected to be undersaturated with respect to aragonite in the annual mean when atmospheric CO2 concentration reaches 513 (606) ppm in year 2046 (2056) in new (old) version. At an atmospheric CO2 concentration of 520 ppm, the maximum differences in pH and aragonite saturation state between the two versions were 0.1 and 0.21 respectively. The analysis showed that the decreases in pH and aragonite saturation state due to rapid sea-ice reduction were caused by increases in both CO2 uptake and freshwater input. Thus, the reductions in pH and aragonite saturation state in the Arctic surface waters are significantly affected by the difference in future projections for sea-ice reduction rate. Our results suggest that the future reductions in pH and aragonite saturation state could be significantly faster than previously projected if the sea-ice reduction in the Arctic Ocean keeps its present pace.},
author = {Yamamoto, A and Kawamiya, M and Ishida, A and Yamanaka, Y and Watanabe, S},
doi = {10.5194/bg-9-2365-2012},
file = {::},
issn = {1726-4189},
journal = {Biogeosciences},
month = {jun},
number = {6},
pages = {2365--2375},
title = {{Impact of rapid sea-ice reduction in the Arctic Ocean on the rate of ocean acidification}},
url = {https://bg.copernicus.org/articles/9/2365/2012/},
volume = {9},
year = {2012}
}
@article{Yamamoto-Kawai2009,
abstract = {The increase in anthropogenic carbon dioxide emissions and attendant increase in ocean acidification and sea ice melt act together to decrease the saturation state of calcium carbonate in the Canada Basin of the Arctic Ocean. In 2008, surface waters were undersaturated with respect to aragonite, a relatively soluble form of calcium carbonate found in plankton and invertebrates. Undersaturation was found to be a direct consequence of the recent extensive melting of sea ice in the Canada Basin. In addition, the retreat of the ice edge well past the shelf-break has produced conditions favorable to enhanced upwelling of subsurface, aragonite-undersaturated water onto the Arctic continental shelf. Undersaturation will affect both planktonic and benthic calcifying biota and therefore the composition of the Arctic ecosystem.},
author = {Yamamoto-Kawai, Michiyo and McLaughlin, Fiona A and Carmack, Eddy C and Nishino, Shigeto and Shimada, Koji},
doi = {10.1126/science.1174190},
issn = {0036-8075},
journal = {Science},
month = {nov},
number = {5956},
pages = {1098--1100},
title = {{Aragonite undersaturation in the Arctic ocean: effects of ocean acidification and sea ice melt}},
url = {http://science.sciencemag.org/content/326/5956/1098.abstract http://www.sciencemag.org/cgi/doi/10.1126/science.1174190},
volume = {326},
year = {2009}
}
@article{Yamori2014,
abstract = {Most plants show considerable capacity to adjust their photosynthetic characteristics to their growth temperatures (temperature acclimation). The most typical case is a shift in the optimum temperature for photosynthesis, which can maximize the photosynthetic rate at the growth temperature. These plastic adjustments can allow plants to photosynthesize more efficiently at their new growth temperatures. In this review article, we summarize the basic differences in photosynthetic reactions in C3, C4, and CAM plants. We review the current understanding of the temperature responses of C3, C4, and CAM photosynthesis, and then discuss the underlying physiological and biochemical mechanisms for temperature acclimation of photosynthesis in each photosynthetic type. Finally, we use the published data to evaluate the extent of photosynthetic temperature acclimation in higher plants, and analyze which plant groups (i.e., photosynthetic types and functional types) have a greater inherent ability for photosynthetic acclimation to temperature than others, since there have been reported interspecific variations in this ability. We found that the inherent ability for temperature acclimation of photosynthesis was different: (1) among C3, C4, and CAM species; and (2) among functional types within C3 plants. C3 plants generally had a greater ability for temperature acclimation of photosynthesis across a broad temperature range, CAM plants acclimated day and night photosynthetic process differentially to temperature, and C4 plants was adapted to warm environments. Moreover, within C3 species, evergreen woody plants and perennial herbaceous plants showed greater temperature homeostasis of photosynthesis (i.e., the photosynthetic rate at high-growth temperature divided by that at low-growth temperature was close to 1.0) than deciduous woody plants and annual herbaceous plants, indicating that photosynthetic acclimation would be particularly important in perennial, long-lived species that would experience a rise in growing season temperatures over their lifespan. Interestingly, across growth temperatures, the extent of temperature homeostasis of photosynthesis was maintained irrespective of the extent of the change in the optimum temperature for photosynthesis (Topt), indicating that some plants achieve greater photosynthesis at the growth temperature by shifting Topt, whereas others can also achieve greater photosynthesis at the growth temperature by changing the shape of the photosynthesis–temperature curve without shifting Topt. It is considered that these differences in the inherent stability of temperature acclimation of photosynthesis would be reflected by differences in the limiting steps of photosynthetic rate.},
author = {Yamori, Wataru and Hikosaka, Kouki and Way, Danielle A},
doi = {10.1007/s11120-013-9874-6},
issn = {1573-5079},
journal = {Photosynthesis Research},
number = {1},
pages = {101--117},
title = {{Temperature response of photosynthesis in C3, C4, and CAM plants: temperature acclimation and temperature adaptation}},
url = {https://doi.org/10.1007/s11120-013-9874-6},
volume = {119},
year = {2014}
}
@article{YANG201969,
abstract = {Biochar application is proposed having a potential of inhibiting greenhouse gases emissions from paddy fields, which is considered to be a main source of atmospheric greenhouse gases. However, the impacts of biochar on greenhouse gases from paddy field have not been investigated under controlled irrigation (CI). Field experiments were conducted during 2016–2017 to determine the effect of biochar application combined with controlled irrigation on rice yield and methane (CH4) and nitrous oxide (N2O) emission from paddy fields in the Taihu Lake Region of China. Four treatments (0 t ha−1 biochar +CI, 20 t ha−1 biochar +CI, 40 t ha−1 biochar +CI, and 40 t ha−1 biochar + flooding irrigation (FI), named CA, CB, CC and FC, respectively) were designed in this study. The results showed that the effect of biochar application on greenhouse gases emissions from paddy fields under controlled irrigation had significant interannual differences. In the first season, CC decreased the global warming potential(GWP) of CH4 and N2O emission, and the CB increased the GWP of CH4 and N2O emission compared to CA, but these differences were not significant. For the second season, CB and CC decreased the GWP of CH4 and N2O emission by 35.7{\%} and 21.5{\%} significantly compared to CA due to the significant mitigation of CH4 and N2O emission. Biochar application significantly increased CH4 emission and decreased N2O emission from paddy fields under flooding irrigation compared to controlled irrigation (CC), which led to the FC's GWP was 1.70 and 5.47 times higher than CC's in the first and second season. In addition, biochar application increased soil organic carbon, dissolved organic carbon and total nitrogen contents of paddy fields under controlled irrigation. And CB and CC increased rice yield by 16.7{\%} and 24.3{\%} and irrigation water productivity by 26.1{\%} and 30.8{\%} compared with CA (mean of two seasons). These results suggest that 20 and 40 t ha−1 biochar can be utilized under controlled irrigation not only for mitigation of CH4 and N2O emission but also to increase rice yield, soil fertility and irrigation water productivity. Therefore, the combination of biochar amendment and controlled irrigation might be a good option for mitigating greenhouse gases emission and realizing the sustainable utilization of soil and water resources of paddy fields in the Taihu Lake Region of China.},
author = {Yang, Shihong and Xiao, Ya'nan and Sun, Xiao and Ding, Jie and Jiang, Zewei and Xu, Junzeng},
doi = {10.1016/j.atmosenv.2018.12.003},
issn = {1352-2310},
journal = {Atmospheric Environment},
keywords = {Biochar,Controlled irrigation,Greenhouse gas,Rice yield,Soil fertility},
pages = {69--77},
title = {{Biochar improved rice yield and mitigated CH4 and N2O emissions from paddy field under controlled irrigation in the Taihu Lake Region of China}},
url = {https://www.sciencedirect.com/science/article/pii/S1352231018308501},
volume = {200},
year = {2019}
}
@article{Yang2019,
author = {Yang, Yuting and Roderick, Michael L. and Zhang, Shulei and McVicar, Tim R. and Donohue, Randall J.},
doi = {10.1038/s41558-018-0361-0},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jan},
number = {1},
pages = {44--48},
publisher = {Springer US},
title = {{Hydrologic implications of vegetation response to elevated CO2 in climate projections}},
url = {http://www.nature.com/articles/s41558-018-0361-0},
volume = {9},
year = {2019}
}
@article{Yang2016a,
abstract = {Geoengineering has been proposed to stabilize global temperature, but its impacts on crop production and stability are not fully understood. A few case studies suggest that certain crops are likely to benefit from solar dimming geoengineering, yet we show that geoengineering is projected to have detrimental effects for groundnut. Using an ensemble of crop-climate model simulations, we illustrate that groundnut yields in India undergo a statistically significant decrease of up to 20{\%} as a result of solar dimming geoengineering relative to RCP4.5. It is somewhat reassuring, however, to find that after a sustained period of 50?years of geoengineering crop yields return to the nongeoengineered values within a few years once the intervention is ceased.},
annote = {doi: 10.1002/2016GL071209},
author = {Yang, Huiyi and Dobbie, Steven and Ramirez-Villegas, Julian and Feng, Kuishuang and Challinor, Andrew J and Chen, Bing and Gao, Yao and Lee, Lindsay and Yin, Yan and Sun, Laixiang and Watson, James and Koehler, Ann-Kristin and Fan, Tingting and Ghosh, Sat},
doi = {10.1002/2016GL071209},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {GLAM,agriculture,climate change,geoengineering,groundnut},
month = {nov},
number = {22},
pages = {11786--11795},
publisher = {John Wiley {\&} Sons, Ltd},
title = {{Potential negative consequences of geoengineering on crop production: A study of Indian groundnut}},
url = {https://doi.org/10.1002/2016GL071209},
volume = {43},
year = {2016}
}
@article{Yang2020,
abstract = {Assessment of the global budget of the greenhouse gas nitrous oxide ( N 2 O) is limited by poor knowledge of the oceanic N 2 O flux to the atmosphere, of which the magnitude, spatial distribution, and temporal variability remain highly uncertain. Here, we reconstruct climatological N 2 O emissions from the ocean by training a supervised learning algorithm with over 158,000 N 2 O measurements from the surface ocean—the largest synthesis to date. The reconstruction captures observed latitudinal gradients and coastal hot spots of N 2 O flux and reveals a vigorous global seasonal cycle. We estimate an annual mean N 2 O flux of 4.2 ± 1.0 Tg N ⋅ y − 1 , 64{\%} of which occurs in the tropics, and 20{\%} in coastal upwelling systems that occupy less than 3{\%} of the ocean area. This N 2 O flux ranges from a low of 3.3 ± 1.3 Tg N ⋅ y − 1 in the boreal spring to a high of 5.5 ± 2.0 Tg N ⋅ y − 1 in the boreal summer. Much of the seasonal variations in global N 2 O emissions can be traced to seasonal upwelling in the tropical ocean and winter mixing in the Southern Ocean. The dominant contribution to seasonality by productive, low-oxygen tropical upwelling systems ({\textgreater}75{\%}) suggests a sensitivity of the global N 2 O flux to El Ni{\~{n}}o–Southern Oscillation and anthropogenic stratification of the low latitude ocean. This ocean flux estimate is consistent with the range adopted by the Intergovernmental Panel on Climate Change, but reduces its uncertainty by more than fivefold, enabling more precise determination of other terms in the atmospheric N 2 O budget.},
author = {Yang, Simon and Chang, Bonnie X. and Warner, Mark J. and Weber, Thomas S. and Bourbonnais, Annie M. and Santoro, Alyson E. and Kock, Annette and Sonnerup, Rolf E. and Bullister, John L. and Wilson, Samuel T. and Bianchi, Daniele},
doi = {10.1073/pnas.1921914117},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {jun},
number = {22},
pages = {11954--11960},
title = {{Global reconstruction reduces the uncertainty of oceanic nitrous oxide emissions and reveals a vigorous seasonal cycle}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1921914117},
volume = {117},
year = {2020}
}
@article{Yang2019a,
author = {Yang, Xiaojuan and Ricciuto, Daniel M. and Thornton, Peter E. and Shi, Xiaoying and Xu, Min and Hoffman, Forrest and Norby, Richard J.},
doi = {10.1029/2019JG005082},
issn = {2169-8953},
journal = {Journal of Geophysical Research: Biogeosciences},
month = {dec},
number = {12},
pages = {3686--3698},
title = {{The Effects of Phosphorus Cycle Dynamics on Carbon Sources and Sinks in the Amazon Region: A Modeling Study Using ELM v1}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2019JG005082},
volume = {124},
year = {2019}
}
@article{Yang2017b,
abstract = {Abstract. Understanding processes controlling the atmospheric methane (CH4) mixing ratio is crucial to predict and mitigate future climate changes in this gas. Despite recent detailed studies of the last ∼ 1000 to 2000 years, the mechanisms that control atmospheric CH4 still remain unclear, partly because the late Holocene CH4 budget may be comprised of both natural and anthropogenic emissions. In contrast, the early Holocene was a period when human influence was substantially smaller, allowing us to elucidate more clearly the natural controls under interglacial conditions more clearly. Here we present new high-resolution CH4 records from Siple Dome, Antarctica, covering from 11.6 to 7.7 thousands of years before 1950AD (ka). We observe four local CH4 minima on a roughly 1000-year spacing, which correspond to cool periods in Greenland. We hypothesize that the cooling in Greenland forced the Intertropical Convergence Zone (ITCZ) to migrate southward, reducing rainfall in northern tropical wetlands. The inter-polar difference (IPD) of CH4 shows a gradual increase from the onset of the Holocene to ∼ 9.5ka, which implies growth of boreal source strength following the climate warming in the northern extratropics during that period.},
author = {Yang, Ji-Woong and Ahn, Jinho and Brook, Edward J. and Ryu, Yeongjun},
doi = {10.5194/cp-13-1227-2017},
issn = {1814-9332},
journal = {Climate of the Past},
month = {sep},
number = {9},
pages = {1227--1242},
title = {{Atmospheric methane control mechanisms during the early Holocene}},
url = {https://www.clim-past.net/13/1227/2017/},
volume = {13},
year = {2017}
}
@article{Yang2020b,
abstract = {Geoengineering by injecting sulfur dioxide (SO2) into the lower stratosphere has been suggested to reduce anthropogenically induced warming. While impacts of such geoengineering on climate have been investigated in recent decades, few modeling studies have considered biogeochemical feedbacks resulting from such intervention. This study comprehensively characterizes responses and feedbacks of terrestrial ecosystems, from an ensemble of coupled high-resolution Earth system model climate change simulations, under the highest standard greenhouse gas scenario with an extreme geoengineering mitigation strategy. Under this strategy, temperature increases beyond 2020 levels due to elevated anthropogenic carbon dioxide (CO2) were completely offset by the SO2 injection. Carbon cycle feedbacks can alter the trajectory of atmospheric CO2 levels by storing or releasing additional carbon on land and in the ocean, thus moderating or amplifying climate change. We assess terrestrial biogeochemical feedbacks to climate in response to geoengineering, using model output from the Stratospheric Aerosol Geoengineering Large Ensemble (GLENS) project. Results indicate terrestrial ecosystems become a stronger carbon sink globally because of lower ecosystem respiration and diminished disturbance effects under geoengineering. An additional 79 Pg C would be stored on land by the end of the twenty-first century, yielding as much as a 4{\%} reduction in atmospheric CO2 mole fraction without marine biogeochemical feedbacks, compared to the high greenhouse gas scenario without geoengineering.},
author = {Yang, Cheng-En and Hoffman, Forrest M and Ricciuto, Daniel M and Tilmes, Simone and Xia, Lili and MacMartin, Douglas G and Kravitz, Ben and Richter, Jadwiga H and Mills, Michael and Fu, Joshua S},
doi = {10.1088/1748-9326/abacf7},
journal = {Environmental Research Letters},
number = {10},
pages = {104043},
publisher = {{\{}IOP{\}} Publishing},
title = {{Assessing terrestrial biogeochemical feedbacks in a strategically geoengineered climate}},
volume = {15},
year = {2020}
}
@article{Yao2018,
abstract = {The consequences of global warming for fisheries are not well understood, but the geological record demonstrates that carbon cycle perturbations are frequently associated with ocean deoxygenation. Of particular interest is the Paleocene-Eocene Thermal Maximum (PETM), where the carbon dioxide input into the atmosphere was similar to the IPCC RCP8.5 emission scenario. Here we present sulfur-isotope data that record a positive 1 per mil excursion during the PETM. Modeling suggests that large parts of the ocean must have become sulfidic. The toxicity of hydrogen sulfide will render two of the largest and least explored ecosystems on Earth, the mesopelagic and bathypelagic zones, uninhabitable by multicellular organisms. This will affect many marine species whose ecozones stretch into the deep ocean.},
author = {Yao, Weiqi and Paytan, Adina and Wortmann, Ulrich G.},
doi = {10.1126/science.aar8658},
issn = {0036-8075},
journal = {Science},
month = {aug},
number = {6404},
pages = {804--806},
pmid = {30026315},
title = {{Large-scale ocean deoxygenation during the Paleocene–Eocene Thermal Maximum}},
url = {http://www.sciencemag.org/lookup/doi/10.1126/science.aar8658},
volume = {361},
year = {2018}
}
@article{Yao2020,
author = {Yao, Yuanzhi and Tian, Hanqin and Shi, Hao and Pan, Shufen and Xu, Rongting and Pan, Naiqing and Canadell, Josep G.},
doi = {10.1038/s41558-019-0665-8},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {feb},
number = {2},
pages = {138--142},
title = {{Increased global nitrous oxide emissions from streams and rivers in the Anthropocene}},
url = {http://www.nature.com/articles/s41558-019-0665-8},
volume = {10},
year = {2020}
}
@article{https://doi.org/10.1111/sum.12546,
abstract = {Abstract The added value of biochar when applied along with fertilizers, beyond that of the fertilizers themselves, has not been summarized. Focusing on direct comparisons between biochar additions (≤20 t ha−1) – separately considering the addition or not of inorganic fertilizers (IF) and/or organic amendments (OA) along with biochar – and two different controls (with and without the addition of IF and/or OA), we carried out a meta-analysis to explain short-term (1-year) field responses in crop yield across different climates, soils, biochars and management practices worldwide. Compared with the non-fertilized control, a 26{\%} (CI: 15{\%}–40{\%}) increase in yield was observed with the use of IF only, whereas that of biochar along with IF caused a 48{\%} (CI: 30{\%}–70{\%}) increase. Compared with the use of IF only, the addition of biochar along with IF caused a 15{\%} (CI: 11{\%}–19{\%}) increase in yield, indicating that biochar was as effective as fertilizers in increasing crop yields when added in combination. The use of biochar alone did not increase crop yield regardless of the control considered. Whereas in the short term, liming may have partly contributed to the beneficial effect of biochar ({\textgreater}90{\%} was plant-derived) when added along with IF, a separate meta-analysis – using those studies that reported crop yields for different years after a single biochar application – showed a 31{\%} (CI: 17{\%}–49{\%}) increase in crop yield over time (≥ 3 years), which denotes the influence of biochar properties other than liming (i.e. an increase in CEC). Our results also suggest that biochar application rates {\textgreater} 10 t ha−1 do not contribute to greater crop yield (at least in the short term). Data limitations precluded identification of the influence of feedstock, production conditions or climatic conditions without bias. As the response of crop yield to biochar addition was less a result of climatic zones or soil type than fertilizer use (chiefly N additions), the choice of nutrient addition along with biochar should be priorities for future research and development regardless of the region.},
author = {Ye, Lili and Camps-Arbestain, Marta and Shen, Qinhua and Lehmann, Johannes and Singh, Balwant and Sabir, Muhammad},
doi = {10.1111/sum.12546},
journal = {Soil Use and Management},
keywords = {biochar,crop yield,inorganic fertilizer,meta-analysis,organic amendment},
number = {1},
pages = {2--18},
title = {{Biochar effects on crop yields with and without fertilizer: A meta-analysis of field studies using separate controls}},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/sum.12546},
volume = {36},
year = {2020}
}
@article{Yeager2018,
abstract = {A new community data resource offers unique capabilities for evaluating the potential for useful Earth system prediction on decadal time scales.},
author = {Yeager, S. G. and Danabasoglu, G. and Rosenbloom, N. A. and Strand, W. and Bates, S. C. and Meehl, G. A. and Karspeck, A. R. and Lindsay, K. and Long, M. C. and Teng, H. and Lovenduski, N. S.},
doi = {10.1175/BAMS-D-17-0098.1},
issn = {0003-0007},
journal = {Bulletin of the American Meteorological Society},
month = {sep},
number = {9},
pages = {1867--1886},
title = {{Predicting near-term changes in the Earth system: a large ensemble of initialized decadal prediction simulations using the community Earth system model}},
url = {http://journals.ametsoc.org/doi/10.1175/BAMS-D-17-0098.1},
volume = {99},
year = {2018}
}
@article{Yin2020,
abstract = {The terrestrial carbon sink has significantly increased in the past decades, but the underlying mechanisms are still unclear. The current synthesis of process-based estimates of land and ocean sinks requires an additional sink of 0.6 PgC yr−1 in the last decade to explain the observed airborne fraction. A concurrent global fire decline was observed in association with tropical agriculture expansion and landscape fragmentation. Here we show that a decline of 0.2 ± 0.1 PgC yr−1 in fire emissions during 2008–2014 relative to 2001–2007 also induced an additional carbon sink enhancement of 0.4 ± 0.2 PgC yr−1 attributable to carbon cycle feedbacks, amounting to a combined sink increase comparable to the 0.6 PgC yr−1 budget imbalance. Our results suggest that the indirect effects of fire, in addition to the direct emissions, is an overlooked mechanism for explaining decadal-scale changes in the land carbon sink and highlight the importance of fire management in climate mitigation.},
author = {Yin, Yi and Bloom, A. Anthony and Worden, John and Saatchi, Sassan and Yang, Yan and Williams, Mathew and Liu, Junjie and Jiang, Zhe and Worden, Helen and Bowman, Kevin and Frankenberg, Christian and Schimel, David},
doi = {10.1038/s41467-020-15852-2},
issn = {20411723},
journal = {Nature Communications},
number = {1},
pages = {1900},
title = {{Fire decline in dry tropical ecosystems enhances decadal land carbon sink}},
volume = {11},
year = {2020}
}
@article{Yokohata2020,
abstract = {The Yedoma layer, a permafrost layer containing a massive amount of underground ice in the Arctic regions, is reported to be rapidly thawing. In this study, we develop the Permafrost Degradation and Greenhouse gasses Emission Model (PDGEM), which describes the thawing of the Arctic permafrost including the Yedoma layer due to climate change and the greenhouse gas (GHG) emissions. The PDGEM includes the processes by which high-concentration GHGs (CO2 and CH4) contained in the pores of the Yedoma layer are released directly by dynamic degradation, as well as the processes by which GHGs are released by the decomposition of organic matter in the Yedoma layer and other permafrost. Our model simulations show that the total GHG emissions from permafrost degradation in the RCP8.5 scenario was estimated to be 31-63 PgC for CO2 and 1261-2821 TgCH4 for CH4 (68th percentile of the perturbed model simulations, corresponding to a global average surface air temperature change of 0.05–0.11 °C), and 14-28 PgC for CO2 and 618-1341 TgCH4 for CH4 (0.03–0.07 °C) in the RCP2.6 scenario. GHG emissions resulting from the dynamic degradation of the Yedoma layer were estimated to be less than 1{\%} of the total emissions from the permafrost in both scenarios, possibly because of the small area ratio of the Yedoma layer. An advantage of PDGEM is that geographical distributions of GHG emissions can be estimated by combining a state-of-the-art land surface model featuring detailed physical processes with a GHG release model using a simple scheme, enabling us to consider a broad range of uncertainty regarding model parameters. In regions with large GHG emissions due to permafrost thawing, it may be possible to help reduce GHG emissions by taking measures such as restraining land development.},
author = {Yokohata, Tokuta and Saito, Kazuyuki and Ito, Akihiko and Ohno, Hiroshi and Tanaka, Katsumasa and Hajima, Tomohiro and Iwahana, Go},
doi = {10.1186/s40645-020-00366-8},
issn = {2197-4284},
journal = {Progress in Earth and Planetary Science},
number = {1},
pages = {56},
title = {{Future projection of greenhouse gas emissions due to permafrost degradation using a simple numerical scheme with a global land surface model}},
url = {https://doi.org/10.1186/s40645-020-00366-8},
volume = {7},
year = {2020}
}
@article{Yoon2018,
abstract = {Abstract. Since the start of the industrial revolution, human activities have caused a rapid increase in atmospheric carbon dioxide (CO2) concentrations, which have, in turn, had an impact on climate leading to global warming and ocean acidification. Various approaches have been proposed to reduce atmospheric CO2. The Martin (or iron) hypothesis suggests that ocean iron fertilization (OIF) could be an effective method for stimulating oceanic carbon sequestration through the biological pump in iron-limited, high-nutrient, low-chlorophyll (HNLC) regions. To test the Martin hypothesis, 13 artificial OIF (aOIF) experiments have been performed since 1990 in HNLC regions. These aOIF field experiments have demonstrated that primary production (PP) can be significantly enhanced by the artificial addition of iron. However, except in the Southern Ocean (SO) European Iron Fertilization Experiment (EIFEX), no significant change in the effectiveness of aOIF (i.e., the amount of iron-induced carbon export flux below the winter mixed layer depth, MLD) has been detected. These results, including possible side effects, have been debated amongst those who support and oppose aOIF experimentation, and many questions concerning the effectiveness of scientific aOIF, environmental side effects, and international aOIF law frameworks remain. In the context of increasing global and political concerns associated with climate change, it is valuable to examine the validity and usefulness of the aOIF experiments. Furthermore, it is logical to carry out such experiments because they allow one to study how plankton-based ecosystems work by providing insight into mechanisms operating in real time and under in situ conditions. To maximize the effectiveness of aOIF experiments under international aOIF regulations in the future, we therefore suggest a design that incorporates several components. (1) Experiments conducted in the center of an eddy structure when grazing pressure is low and silicate levels are high (e.g., in the SO south of the polar front during early summer). (2) Shipboard observations extending over a minimum of ∼40 days, with multiple iron injections (at least two or three iron infusions of ∼2000kg with an interval of ∼10–15 days to fertilize a patch of 300km2 and obtain a ∼2nM concentration). (3) Tracing of the iron-fertilized patch using both physical (e.g., a drifting buoy) and biogeochemical (e.g., sulfur hexafluoride, photosynthetic quantum efficiency, and partial pressure of CO2) tracers. (4) Employment of neutrally buoyant sediment traps (NBST) and application of the water-column-derived thorium-234 (234Th) method at two depths (i.e., just below the in situ MLD and at the winter MLD), with autonomous profilers equipped with an underwater video profiler (UVP) and a transmissometer. (5) Monitoring of side effects on marine/ocean ecosystems, including production of climate-relevant gases (e.g., nitrous oxide, N2O; dimethyl sulfide, DMS; and halogenated volatile organic compounds, HVOCs), decline in oxygen inventory, and development of toxic algae blooms, with optical-sensor-equipped autonomous moored profilers and/or autonomous benthic vehicles. Lastly, we introduce the scientific aOIF experimental design guidelines for a future Korean Iron Fertilization Experiment in the Southern Ocean (KIFES). ]]{\textgreater}},
author = {Yoon, Joo-Eun and Yoo, Kyu-Cheul and Macdonald, Alison M. and Yoon, Ho-Il and Park, Ki-Tae and Yang, Eun Jin and Kim, Hyun-Cheol and Lee, Jae Il and Lee, Min Kyung and Jung, Jinyoung and Park, Jisoo and Lee, Jiyoung and Kim, Soyeon and Kim, Seong-Su and Kim, Kitae and Kim, Il-Nam},
doi = {10.5194/bg-15-5847-2018},
issn = {1726-4189},
journal = {Biogeosciences},
month = {oct},
number = {19},
pages = {5847--5889},
title = {{Reviews and syntheses: Ocean iron fertilization experiments – past, present, and future looking to a future Korean Iron Fertilization Experiment in the Southern Ocean (KIFES) project}},
url = {https://www.biogeosciences.net/15/5847/2018/},
volume = {15},
year = {2018}
}
@article{Yoshida2013,
abstract = {Abstract. The column-averaged dry-air mole fractions of carbon dioxide and methane (XCO2 and XCH4) have been retrieved from Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed (SWIR) observations and released as a SWIR L2 product from the National Institute for Environmental Studies (NIES). XCO2 and XCH4 retrieved using the version 01.xx retrieval algorithm showed large negative biases and standard deviations (−8.85 and 4.75 ppm for XCO2 and −20.4 and 18.9 ppb for XCH4, respectively) compared with data of the Total Carbon Column Observing Network (TCCON). Multiple reasons for these error characteristics (e.g., solar irradiance database, handling of aerosol scattering) are identified and corrected in a revised version of the retrieval algorithm (version 02.xx). The improved retrieval algorithm shows much smaller biases and standard deviations (−1.48 and 2.09 ppm for XCO2 and −5.9 and 12.6 ppb for XCH4, respectively) than the version 01.xx. Also, the number of post-screened measurements is increased, especially at northern mid- and high-latitudinal areas.},
author = {Yoshida, Y. and Kikuchi, N. and Morino, I. and Uchino, O. and Oshchepkov, S. and Bril, A. and Saeki, T. and Schutgens, N. and Toon, G. C. and Wunch, D. and Roehl, C. M. and Wennberg, P. O. and Griffith, D. W. T. and Deutscher, N. M. and Warneke, T. and Notholt, J. and Robinson, J. and Sherlock, V. and Connor, B. and Rettinger, M. and Sussmann, R. and Ahonen, P. and Heikkinen, P. and Kyr{\"{o}}, E. and Mendonca, J. and Strong, K. and Hase, F. and Dohe, S. and Yokota, T.},
doi = {10.5194/amt-6-1533-2013},
issn = {1867-8548},
journal = {Atmospheric Measurement Techniques},
month = {jun},
number = {6},
pages = {1533--1547},
title = {{Improvement of the retrieval algorithm for GOSAT SWIR XCO2 and XCH4 and their validation using TCCON data}},
url = {https://amt.copernicus.org/articles/6/1533/2013/},
volume = {6},
year = {2013}
}
@article{Yu2010,
abstract = {Deep-ocean carbonate ion concentrations ([CO32–]) and carbon isotopic ratios (d13C) place important constraints on past redistributions of carbon in the ocean-land-atmosphere system and hence provide clues to the causes of atmospheric CO2 concentration changes. However, existing deep-sea [CO32–] reconstructions conflict with one another, complicating paleoceanographic interpretations. Here, we present deep-sea [CO32–] for five cores from the three major oceans quantified using benthic foraminiferal boron/calcium ratios since the last glacial period. Combined benthic d13C and [CO32–] results indicate that deep-sea-released CO2 during the early deglacial period (17.5 to 14.5 thousand years ago) was preferentially stored in the atmosphere, whereas during the late deglacial period (14 to 10 thousand years ago), besides contributing to the contemporary atmospheric CO2 rise, a substantial portion of CO2 released from oceans was absorbed by the terrestrial biosphere},
author = {Yu, Jimin and Broecker, Wally S. and Elderfield, Harry and Jin, Zhangdong and McManus, Jerry and Zhang, Fei},
doi = {10.1126/science.1193221},
issn = {0036-8075},
journal = {Science},
month = {nov},
number = {6007},
pages = {1084--1087},
title = {{Loss of carbon from the Deep Sea since the last glacial maximum}},
url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1193221},
volume = {330},
year = {2010}
}
@article{Yu2019a,
abstract = {Forests play a major role in the global carbon cycle. Previous studies on the capacity of forests to sequester atmospheric CO 2 have mostly focused on carbon uptake, but the roles of carbon turnover time and its spatiotemporal changes remain poorly understood. Here, we used long-term inventory data (1955 to 2018) from 695 mature forest plots to quantify temporal trends in living vegetation carbon turnover time across tropical, temperate, and cold climate zones, and compared plot data to 8 Earth system models (ESMs). Long-term plots consistently showed decreases in living vegetation carbon turnover time, likely driven by increased tree mortality across all major climate zones. Changes in living vegetation carbon turnover time were negatively correlated with CO 2 enrichment in both forest plot data and ESM simulations. However, plot-based correlations between living vegetation carbon turnover time and climate drivers such as precipitation and temperature diverged from those of ESM simulations. Our analyses suggest that forest carbon sinks are likely to be constrained by a decrease in living vegetation carbon turnover time, and accurate projections of forest carbon sink dynamics will require an improved representation of tree mortality processes and their sensitivity to climate in ESMs.},
author = {Yu, Kailiang and Smith, William K. and Trugman, Anna T. and Condit, Richard and Hubbell, Stephen P. and Sardans, Jordi and Peng, Changhui and Zhu, Kai and Pe{\~{n}}uelas, Josep and Cailleret, Maxime and Levanic, Tom and Gessler, Arthur and Schaub, Marcus and Ferretti, Marco and Anderegg, William R. L.},
doi = {10.1073/pnas.1821387116},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {dec},
number = {49},
pages = {24662--24667},
title = {{Pervasive decreases in living vegetation carbon turnover time across forest climate zones}},
url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1821387116},
volume = {116},
year = {2019}
}
@article{Yu2019b,
abstract = {During the Last Glacial Maximum (LGM; {\~{}}20,000 years ago), the global ocean sequestered a large amount of carbon lost from the atmosphere and terrestrial biosphere. Suppressed CO2 outgassing from the Southern Ocean is the prevailing explanation for this carbon sequestration. By contrast, the North Atlantic Ocean—a major conduit for atmospheric CO2 transport to the ocean interior via the overturning circulation—has received much less attention. Here we demonstrate that North Atlantic carbon pump efficiency during the LGM was almost doubled relative to the Holocene. This is based on a novel proxy approach to estimate air–sea CO2 exchange signals using combined carbonate ion and nutrient reconstructions for multiple sediment cores from the North Atlantic. Our data indicate that in tandem with Southern Ocean processes, enhanced North Atlantic CO2 absorption contributed to lowering ice-age atmospheric CO2.},
author = {Yu, J. and Menviel, L. and Jin, Z. D. and Thornalley, D. J.R. and Foster, G. L. and Rohling, E. J. and McCave, I. N. and McManus, J. F. and Dai, Y. and Ren, H. and He, F. and Zhang, F. and Chen, P. J. and Roberts, A. P.},
doi = {10.1038/s41467-019-10028-z},
isbn = {4146701910},
issn = {20411723},
journal = {Nature Communications},
number = {1},
pages = {1--11},
pmid = {31092826},
title = {{More efficient North Atlantic carbon pump during the Last Glacial Maximum}},
volume = {10},
year = {2019}
}
@article{Yu2017b,
author = {Yu, Lijun and Huang, Yao and Zhang, Wen and Li, Tingting and Sun, Wenjuan},
doi = {10.1016/j.scitotenv.2017.07.082},
issn = {00489697},
journal = {Science of The Total Environment},
month = {dec},
pages = {1163--1172},
title = {{Methane uptake in global forest and grassland soils from 1981 to 2010}},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0048969717317862},
volume = {607-608},
year = {2017}
}
@article{Yue2018a,
abstract = {Fire emissions generate air pollutants ozone (O 3 ) and aerosols that influence the land carbon cycle. Surface O 3 damages vegetation photosynthesis through stomatal uptake, while aerosols influence photosynthesis by increasing diffuse radiation. Here we combine several state-of-the-art models and multiple measurement datasets to assess the net impacts of fire-induced O 3 damage and the aerosol diffuse fertilization effect on gross primary productivity (GPP) for the 2002–2011 period. With all emissions except fires, O 3 decreases global GPP by 4.0 ± 1.9 Pg C yr −1 while aerosols increase GPP by 1.0 ± 0.2 Pg C yr −1 with contrasting spatial impacts. Inclusion of fire pollution causes a further GPP reduction of 0.86 ± 0.74 Pg C yr −1 during 2002–2011, resulting from a reduction of 0.91 ± 0.44 Pg C yr −1 by O 3 and an increase of 0.05 ± 0.30 Pg C yr −1 by aerosols. The net negative impact of fire pollution poses an increasing threat to ecosystem productivity in a warming future world.},
author = {Yue, Xu and Unger, Nadine},
doi = {10.1038/s41467-018-07921-4},
issn = {2041-1723},
journal = {Nature Communications},
month = {dec},
number = {1},
pages = {5413},
title = {{Fire air pollution reduces global terrestrial productivity}},
url = {http://www.nature.com/articles/s41467-018-07921-4},
volume = {9},
year = {2018}
}
@article{Zachos2005,
abstract = {The Paleocene-Eocene thermal maximum (PETM) has been attributed to the rapid release of approximately 2000 x 10(9) metric tons of carbon in the form of methane. In theory, oxidation and ocean absorption of this carbon should have lowered deep-sea pH, thereby triggering a rapid ({\textless}10,000-year) shoaling of the calcite compensation depth (CCD), followed by gradual recovery. Here we present geochemical data from five new South Atlantic deep-sea sections that constrain the timing and extent of massive sea-floor carbonate dissolution coincident with the PETM. The sections, from between 2.7 and 4.8 kilometers water depth, are marked by a prominent clay layer, the character of which indicates that the CCD shoaled rapidly ({\textless}10,000 years) by more than 2 kilometers and recovered gradually ({\textgreater}100,000 years). These findings indicate that a large mass of carbon ({\textgreater}2000 x 10(9) metric tons of carbon) dissolved in the ocean at the Paleocene-Eocene boundary and that permanent sequestration of this carbon occurred through silicate weathering feedback.},
annote = {10.1126/science.1109004},
author = {Zachos, James C. and R{\"{o}}hl, Ursula and Schellenberg, Stephen A. and Sluijs, Appy and Hodell, David A. and Kelly, Daniel C. and Thomas, Ellen and Nicolo, Micah and Raffi, Isabella and Lourens, Lucas J. and McCarren, Heather and Kroon, Dick},
doi = {10.1126/science.1109004},
issn = {0036-8075},
journal = {Science},
month = {jun},
number = {5728},
pages = {1611--1615},
pmid = {15947184},
title = {{Rapid Acidification of the Ocean During the Paleocene–Eocene Thermal Maximum}},
url = {https://www.sciencemag.org/lookup/doi/10.1126/science.1109004},
volume = {308},
year = {2005}
}
@article{RN653,
abstract = {Coupled carbon cycle–climate models in the Coupled Model Intercomparison Project, phase 5 (CMIP5), Earth system model ensemble simulate the effects of changes in anthropogenic fossil-fuel emissions and ensuing climatic changes on the global carbon (C) balance but largely ignore the consequences of widespread terrestrial nitrogen (N) limitation. Based on plausible ranges of terrestrial C:N stoichiometry, this study investigates whether the terrestrial C sequestration projections of nine CMIP5 models for four representative concentration pathways (RCPs) are consistent with estimates of N supply from increased biological fixation, atmospheric deposition, and reduced ecosystem N losses. Discrepancies between the timing and places of N demand and supply indicated increases in terrestrial N implicit to the projections of all nine CMIP5 models under all scenarios that are larger than the estimated N supply. Omitting N constraints leads to an overestimation of land C sequestration in these models between the years 1860 and 2100 by between 97 Pg C (69–252 Pg C; RCP 2.6) and 150 Pg C (57–323 Pg C; RCP 8.5), with a large spread across models. The CMIP5 models overestimated the average 2006–2100 fossil-fuel emissions required to keep atmospheric CO2 levels on the trajectories described in the RCP scenarios by between 0.6 Pg C yr−1 (0.4–2.2 Pg C yr−1; RCP 2.6) and 1.2 Pg C yr−1 (0.5–3.3 Pg C yr−1; RCP 8.5). If unabated, reduced land C sequestration would enhance CO2 accumulation in the ocean and atmosphere, increasing atmospheric CO2 burden by 26 ppm (16–88 ppm; RCP 2.6) to 61 ppm (29–147 ppm; RCP 8.5) by the year 2100.},
author = {Zaehle, S{\"{o}}nke and Jones, Chris D. and Houlton, Benjamin and Lamarque, Jean-Francois and Robertson, Eddy},
doi = {10.1175/JCLI-D-13-00776.1},
isbn = {0894-8755},
issn = {0894-8755},
journal = {Journal of Climate},
month = {mar},
number = {6},
pages = {2494--2511},
title = {{Nitrogen Availability Reduces CMIP5 Projections of Twenty-First-Century Land Carbon Uptake}},
type = {Journal Article},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-13-00776.1},
volume = {28},
year = {2015}
}
@article{Zaehle2014,
abstract = {We analysed the responses of 11 ecosystem models to elevated atmospheric [CO2 ] (eCO2 ) at two temperate forest ecosystems (Duke and Oak Ridge National Laboratory (ORNL) Free-Air CO2 Enrichment (FACE) experiments) to test alternative representations of carbon (C)-nitrogen (N) cycle processes. We decomposed the model responses into component processes affecting the response to eCO2 and confronted these with observations from the FACE experiments. Most of the models reproduced the observed initial enhancement of net primary production (NPP) at both sites, but none was able to simulate both the sustained 10-yr enhancement at Duke and the declining response at ORNL: models generally showed signs of progressive N limitation as a result of lower than observed plant N uptake. Nonetheless, many models showed qualitative agreement with observed component processes. The results suggest that improved representation of above-ground-below-ground interactions and better constraints on plant stoichiometry are important for a predictive understanding of eCO2 effects. Improved accuracy of soil organic matter inventories is pivotal to reduce uncertainty in the observed C-N budgets. The two FACE experiments are insufficient to fully constrain terrestrial responses to eCO2 , given the complexity of factors leading to the observed diverging trends, and the consequential inability of the models to explain these trends. Nevertheless, the ecosystem models were able to capture important features of the experiments, lending some support to their projections.},
author = {Zaehle, S{\"{o}}nke and Medlyn, Belinda E. and {De Kauwe}, Martin G. and Walker, Anthony P. and Dietze, Michael C. and Hickler, Thomas and Luo, Yiqi and Wang, Ying-Ping and El-Masri, Bassil and Thornton, Peter and Jain, Atul and Wang, Shusen and Warlind, David and Weng, Ensheng and Parton, William and Iversen, Colleen M. and Gallet-Budynek, Anne and McCarthy, Heather and Finzi, Adrien and Hanson, Paul J. and Prentice, I. Colin and Oren, Ram and Norby, Richard J.},
doi = {10.1111/nph.12697},
isbn = {1469-8137},
issn = {0028646X},
journal = {New Phytologist},
keywords = {Carbon (C) storage,Ecosystem modelling,Model evaluation,Nitrogen (N) limitation,Plant physiology},
month = {may},
number = {3},
pages = {803--822},
pmid = {24467623},
title = {{Evaluation of 11 terrestrial carbon–nitrogen cycle models against observations from two temperate free-air CO2 Enrichment studies}},
url = {https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.12697 http://doi.wiley.com/10.1111/nph.12697},
volume = {202},
year = {2014}
}
@article{Zaehle2010,
abstract = {The effects of nitrogen (N) constraints on future terrestrial carbon (C) dynamics are investigated using the O-CN land surface model. The model's responses to elevated {\{}[{\}}CO2] and soil warming agree well with observations made in ecosystem manipulation studies. N dynamics reduce terrestrial C storage due to CO2 fertilization over the period 1860-2100 by similar to 50{\%} (342 Pg C) mainly in mid-high latitude ecosystems, compared to a simulation not accounting for N dynamics. Conversely, N dynamics reduce projected losses of land C due to increasing temperature by 16{\%} (49 Pg C); however, this effect is prevalent only in mid-high latitude ecosystems. Despite synergistic interactions, the balance of these opposing effects is a significant reduction in future net land C storage. Terrestrial N dynamics thereby consistently increase atmospheric {\{}[{\}}CO2] in the year 2100 with a median value of 48 (41-55) ppmv, corresponding to an additional radiative forcing of 0.29 (0.28-0.34) W m(-2). Citation: Zaehle, S., P. Friedlingstein, and A. D. Friend (2010), Terrestrial nitrogen feedbacks may accelerate future climate change, Geophys. Res. Lett., 37, L01401, doi:10.1029/2009GL041345.},
author = {Zaehle, S{\"{o}}nke and Friedlingstein, Pierre and Friend, Andrew D.},
doi = {10.1029/2009GL041345},
isbn = {0094-8276},
issn = {00948276},
journal = {Geophysical Research Letters},
number = {1},
pages = {L01401},
title = {{Terrestrial nitrogen feedbacks may accelerate future climate change}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2009GL041345},
volume = {37},
year = {2010}
}
@article{Zaehle2013a,
abstract = {Interactions between the terrestrial nitrogen (N) and carbon (C) cycles shape the response of ecosystems to global change. However, the global distribution of nitrogen availability and its importance in global biogeochemistry and biogeochemical interactions with the climate system remain uncertain. Based on projections of a terrestrial biosphere model scaling ecological understanding of nitrogen–carbon cycle interactions to global scales, anthropogenic nitrogen additions since 1860 are estimated to have enriched the terrestrial biosphere by 1.3 Pg N, supporting the sequestration of 11.2 Pg C. Over the same time period, CO 2 fertilization has increased terrestrial carbon storage by 134.0 Pg C, increasing the terrestrial nitrogen stock by 1.2 Pg N. In 2001–2010, terrestrial ecosystems sequestered an estimated total of 27 Tg N yr −1 (1.9 Pg C yr −1 ), of which 10 Tg N yr −1 (0.2 Pg C yr −1 ) are due to anthropogenic nitrogen deposition. Nitrogen availability already limits terrestrial carbon sequestration in the boreal and temperate zone, and will constrain future carbon sequestration in response to CO 2 fertilization (regionally by up to 70{\%} compared with an estimate without considering nitrogen–carbon interactions). This reduced terrestrial carbon uptake will probably dominate the role of the terrestrial nitrogen cycle in the climate system, as it accelerates the accumulation of anthropogenic CO 2 in the atmosphere. However, increases of N 2 O emissions owing to anthropogenic nitrogen and climate change (at a rate of approx. 0.5 Tg N yr −1 per 1°C degree climate warming) will add an important long-term climate forcing.},
author = {Zaehle, S.},
doi = {10.1098/rstb.2013.0125},
issn = {0962-8436},
journal = {Philosophical Transactions of the Royal Society B: Biological Sciences},
keywords = {Biogeochemistry-climate interactions,Carbon sequestration,Nitrogen deposition,Terrestrial carbon and nitrogen budget},
month = {jul},
number = {1621},
pages = {20130125},
title = {{Terrestrial nitrogen–carbon cycle interactions at the global scale}},
url = {http://rstb.royalsocietypublishing.org/cgi/doi/10.1098/rstb.2013.0125 https://royalsocietypublishing.org/doi/10.1098/rstb.2013.0125},
volume = {368},
year = {2013}
}
@article{bg-9-5007-2012,
abstract = {Abstract. The eastern tropical Pacific (ETP) is believed to be one of the largest marine sources of the greenhouse gas nitrous oxide (N2O). Future N2O emissions from the ETP are highly uncertain because oxygen minimum zones are expected to expand, affecting both regional production and consumption of N2O. Here we assess three primary uncertainties in how N2O may respond to changing O2 levels: (1) the relationship between N2O production and O2 (is it linear or exponential at low O2 concentrations?), (2) the cutoff point at which net N2O production switches to net N2O consumption (uncertainties in this parameterisation can lead to differences in model ETP N2O concentrations of more than 20{\%}), and (3) the rate of net N2O consumption at low O2. Based on the MEMENTO database, which is the largest N2O dataset currently available, we find that N2O production in the ETP increases linearly rather than exponentially with decreasing O2. Additionally, net N2O consumption switches to net N2O production at {\~{}} 10 $\mu$M O2, a value in line with recent studies that suggest consumption occurs on a larger scale than previously thought. N2O consumption is on the order of 0.01–1 mmol N2O m−3 yr−1 in the Peru-Chile Undercurrent. Based on these findings, it appears that recent studies substantially overestimated N2O production in the ETP. In light of expected deoxygenation and the higher than previously expected point at which net N2O production switches to consumption, there is enough uncertainty in future N2O production that even the sign of future changes is still unclear.},
author = {Zamora, L M and Oschlies, A and Bange, H W and Huebert, K B and Craig, J D and Kock, A and L{\"{o}}scher, C R},
doi = {10.5194/bg-9-5007-2012},
issn = {1726-4189},
journal = {Biogeosciences},
month = {dec},
number = {12},
pages = {5007--5022},
title = {{Nitrous oxide dynamics in low oxygen regions of the Pacific: insights from the MEMENTO database}},
url = {https://www.biogeosciences.net/9/5007/2012/},
volume = {9},
year = {2012}
}
@article{Zeebe2016a,
abstract = {Carbon release rates from anthropogenic sources reached a record high of ∼10 Pg C yr−1 in 2014. Geologic analogues from past transient climate changes could provide invaluable constraints on the response of the climate system to such perturbations, but only if the associated carbon release rates can be reliably reconstructed. The Palaeocene–Eocene Thermal Maximum (PETM) is known at present to have the highest carbon release rates of the past 66 million years, but robust estimates of the initial rate and onset duration are hindered by uncertainties in age models. Here we introduce a new method to extract rates of change from a sedimentary record based on the relative timing of climate and carbon cycle changes, without the need for an age model. We apply this method to stable carbon and oxygen isotope records from the New Jersey shelf using timeseries analysis and carbon cycle–climate modelling. We calculate that the initial carbon release during the onset of the PETM occurred over at least 4,000 years. This constrains the maximum sustained PETM carbon release rate to less than 1.1 Pg C yr−1 . We conclude that, given currently available records, the present anthropogenic carbon release rate is unprecedented during the past 66 million years. We suggest that such a ‘no-analogue' state represents a fundamental challenge in constraining future climate projections. Also, future ecosystem disruptions are likely to exceed the relatively limited extinctions observed at the PETM.},
author = {Zeebe, Richard E. and Ridgwell, Andy and Zachos, James C.},
doi = {10.1038/ngeo2681},
isbn = {1752-0894},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {apr},
number = {4},
pages = {325--329},
title = {{Anthropogenic carbon release rate unprecedented during the past 66 million years}},
url = {http://www.nature.com/articles/ngeo2681},
volume = {9},
year = {2016}
}
@article{Zeebe2009,
abstract = {The Palaeocene–Eocene Thermal Maximum (about 55 Myr ago) represents a possible analogue for the future and thus may provide insight into climate system sensitivity and feedbacks1,2. The key feature of this event is the release of a large mass of 13C-depleted carbon into the carbon reservoirs at the Earth's surface, although the source remains an open issue3,4. Concurrently, global surface temperatures rose by 5–9 ∘C within a few thousand years5,6,7,8,9. Here we use published palaeorecords of deep-sea carbonate dissolution10,11,12,13,14 and stable carbon isotope composition10,15,16,17 along with a carbon cycle model to constrain the initial carbon pulse to a magnitude of 3,000 Pg C or less, with an isotopic composition lighter than −50‰. As a result, atmospheric carbon dioxide concentrations increased during the main event by less than about 70{\%} compared with pre-event levels. At accepted values for the climate sensitivity to a doubling of the atmospheric CO2 concentration1, this rise in CO2 can explain only between 1 and 3.5 ∘C of the warming inferred from proxy records. We conclude that in addition to direct CO2 forcing, other processes and/or feedbacks that are hitherto unknown must have caused a substantial portion of the warming during the Palaeocene–Eocene Thermal Maximum. Once these processes have been identified, their potential effect on future climate change needs to be taken into account.},
author = {Zeebe, Richard E and Zachos, James C and Dickens, Gerald R},
doi = {10.1038/ngeo578},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {aug},
number = {8},
pages = {576--580},
publisher = {Nature Publishing Group},
title = {{Carbon dioxide forcing alone insufficient to explain Palaeocene–Eocene Thermal Maximum warming}},
url = {http://dx.doi.org/10.1038/ngeo578 http://www.nature.com/articles/ngeo578},
volume = {2},
year = {2009}
}
@incollection{Zeebe2009a,
address = {Dordrecht, The Netherlands},
author = {Zeebe, Richard E. and Wolf-Gladrow, Dieter A.},
booktitle = {Encyclopedia of Paleoclimatology and Ancient Environments},
doi = {10.1007/978-1-4020-4411-3_30},
editor = {Gornitz, V.},
pages = {1037--1039},
publisher = {Springer},
series = {Encyclopedia of Earth Sciences Series},
title = {{Carbon Dioxide, Dissolved (Ocean)}},
year = {2009}
}
@article{Zemp2017,
annote = {added by A.Eliseev 25.01.2019},
author = {Zemp, Delphine Clara and Schleussner, Carl-Friedrich and Barbosa, Henrique M J and Hirota, Marina and Montade, Vincent and Sampaio, Gilvan and Staal, Arie and Wang-Erlandsson, Lan and Rammig, Anja},
doi = {10.1038/ncomms14681},
issn = {2041-1723},
journal = {Nature Communications},
month = {mar},
pages = {14681},
publisher = {The Author(s)},
title = {{Self-amplified Amazon forest loss due to vegetation–atmosphere feedbacks}},
url = {http://www.nature.com/doifinder/10.1038/ncomms14681},
volume = {8},
year = {2017}
}
@article{Zeng2014a,
abstract = {A feed-forward neural network is used to create a monthly climatology of the sea surface fugacity of CO2 (fCO2) on a 1° × 1° spatial resolution. Using 127 880 data points from 1990 to 2011 in the track-gridded database of the Surface Ocean CO2 Atlas version 2.0 (Bakker et al.), the model yields a global mean fCO2 increase rate of 1.50 $\mu$atm yr−1. The rate was used to normalize multiple years' fCO2 observations to the reference year of 2000. A total of 73 265 data points from the normalized data were used to model the global fCO2 climatology. The model simulates monthly fCO2 distributions that agree well with observations and yields an anthropogenic CO2 update of −1.9 to −2.3 PgC yr−1. The range reflects the uncertainty related to using different wind products for the flux calculation. This estimate is in good agreement with the recently derived best estimate by Wanninkhof et al. The model product benefits from a finer spatial resolution compared to the product of Lamont–Doherty Earth Observatory (Takahashi et al.), which is currently the most frequently used product. It therefore has the potential to improve estimates of the global ocean CO2 uptake. The method's benefits include but are not limited to the following: (i) a fixed structure is not required to model fCO2 as a nonlinear function of biogeochemical variables, (ii) only one neural network configuration is sufficient to model global fCO2 in all seasons, and (iii) the model can be extended to produce global fCO2 maps at a higher resolution in time and space as long as the required data for input variables are available.},
author = {Zeng, J. and Nojiri, Y. and Landsch{\"{u}}tzer, P. and Telszewski, M. and Nakaoka, S.},
doi = {10.1175/JTECH-D-13-00137.1},
issn = {0739-0572},
journal = {Journal of Atmospheric and Oceanic Technology},
month = {aug},
number = {8},
pages = {1838--1849},
title = {{A Global Surface Ocean fCO2 Climatology Based on a Feed-Forward Neural Network}},
url = {http://journals.ametsoc.org/doi/10.1175/JTECH-D-13-00137.1},
volume = {31},
year = {2014}
}
@article{Zeng2008,
abstract = {Using a 25-year hindcast experiment, we explore the possibility of seasonal-interannual prediction of terrestrial ecosystems and the global carbon cycle. This has been achieved using a prototype forecasting system in which the dynamic vegetation and terrestrial carbon cycle model VEGAS was forced with 15-member ensemble climate predictions generated by the NOAA/NCEP coupled climate forecasting system (CFS) for the period 1981-2005, with lead times up to 9 months. The results show that the predictability is dominated by the ENSO signal with its major influence on the tropical and subtropical regions, including South America, Indonesia, southern Africa, eastern Australia, western United States, and central Asia. There is also important non-ENSO related predictability such as that associated with midlatitude drought Comparison of the dynamical prediction results with benchmark statistical prediction methods such as anomaly persistence and damping show that the dynamical method performs significantly better. The hindcasted ecosystem variables and carbon flux show significantly slower decrease in skill at longer lead time compared to the climate forcing variables, partly because of the memories in land and vegetation processes that filter out the higher-frequency noise and sustain the signal. Copyright 2008 by the American Geophysical Union.},
author = {Zeng, Ning and Yoon, Jin-Ho and Vintzileos, Augustin and Collatz, G. James and Kalnay, Eugenia and Mariotti, Annarita and Kumar, Arun and Busalacchi, Antonio and Lord, Stephen},
doi = {10.1029/2008GB003183},
issn = {08866236},
journal = {Global Biogeochemical Cycles},
month = {dec},
number = {4},
pages = {GB4015},
title = {{Dynamical prediction of terrestrial ecosystems and the global carbon cycle: A 25-year hindcast experiment}},
url = {http://doi.wiley.com/10.1029/2008GB003183},
volume = {22},
year = {2008}
}
@article{Zhang2017,
abstract = {Conventional greenhouse gas mitigation policies ignore the role of global wetlands in emitting methane (CH4) from feedbacks associated with changing climate. Here we investigate wetland feedbacks and whether, and to what degree, wetlands will exceed anthropogenic 21st century CH4 emissions using an ensemble of climate projections and a biogeochemical methane model with dynamic wetland area and permafrost. Our results reveal an emerging contribution of global wetland CH4 emissions due to processes mainly related to the sensitivity of methane emissions to temperature and changing global wetland area. We highlight that climate-change and wetland CH4 feedbacks to radiative forcing are an important component of climate change and should be represented in policies aiming to mitigate global warming below 2{\{}$\backslash$textdegree{\}}C.Wetland methane (CH4) emissions are the largest natural source in the global CH4 budget, contributing to roughly one third of total natural and anthropogenic emissions. As the second most important anthropogenic greenhouse gas in the atmosphere after CO2, CH4 is strongly associated with climate feedbacks. However, due to the paucity of data, wetland CH4 feedbacks were not fully assessed in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The degree to which future expansion of wetlands and CH4 emissions will evolve and consequently drive climate feedbacks is thus a question of major concern. Here we present an ensemble estimate of wetland CH4 emissions driven by 38 general circulation models for the 21st century. We find that climate change-induced increases in boreal wetland extent and temperature-driven increases in tropical CH4 emissions will dominate anthropogenic CH4 emissions by 38 to 56{\%} toward the end of the 21st century under the Representative Concentration Pathway (RCP2.6). Depending on scenarios, wetland CH4 feedbacks translate to an increase in additional global mean radiative forcing of 0.04 W{\textperiodcentered}m-2 to 0.19 W{\textperiodcentered}m-2 by the end of the 21st century. Under the {\{}$\backslash$textquotedblleft{\}}worst-case{\{}$\backslash$textquotedblright{\}} RCP8.5 scenario, with no climate mitigation, boreal CH4 emissions are enhanced by 18.05 Tg to 41.69 Tg, due to thawing of inundated areas during the cold season (December to May) and rising temperature, while tropical CH4 emissions accelerate with a total increment of 48.36 Tg to 87.37 Tg by 2099. Our results suggest that climate mitigation policies must consider mitigation of wetland CH4 feedbacks to maintain average global warming below 2 {\{}$\backslash$textdegree{\}}C.},
author = {Zhang, Zhen and Zimmermann, Niklaus E and Stenke, Andrea and Li, Xin and Hodson, Elke L and Zhu, Gaofeng and Huang, Chunlin and Poulter, Benjamin},
doi = {10.1073/pnas.1618765114},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {sep},
number = {36},
pages = {9647--9652},
publisher = {National Academy of Sciences},
title = {{Emerging role of wetland methane emissions in driving 21st century climate change}},
url = {http://www.pnas.org/content/114/36/9647 http://www.pnas.org/lookup/doi/10.1073/pnas.1618765114},
volume = {114},
year = {2017}
}
@article{Zhang2014,
author = {Zhang, Q. and Wang, Y. P. and Matear, R. J. and Pitman, A. J. and Dai, Y. J.},
doi = {10.1002/2013GL058352},
issn = {00948276},
journal = {Geophysical Research Letters},
month = {jan},
number = {2},
pages = {632--637},
title = {{Nitrogen and phosphorous limitations significantly reduce future allowable CO2 emissions}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2013GL058352 http://doi.wiley.com/10.1002/2013GL058352},
volume = {41},
year = {2014}
}
@article{Zhang2013b,
author = {Zhang, Yi Ge and Pagani, Mark and Liu, Zhonghui and Bohaty, Steven M and DeConto, R.},
doi = {10.1098/rsta.2013.0096},
issn = {1364-503X},
journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences},
month = {sep},
number = {2001},
pages = {20130096},
title = {{A 40-million-year history of atmospheric CO2}},
url = {https://doi.org/10.1098/rsta.2013.0096 http://rsta.royalsocietypublishing.org/cgi/doi/10.1098/rsta.2013.0096},
volume = {371},
year = {2013}
}
@article{Zhang2013,
abstract = {One major challenge to the improvement of regional climate scenarios for the northern high latitudes is to understand land surface feedbacks associated with vegetation shifts and ecosystem biogeochemical cycling. We employed a customized, Arctic version of the individual-based dynamic vegetation model LPJ-GUESS to simulate the dynamics of upland and wetland ecosystems under a regional climate model–downscaled future climate projection for the Arctic and Subarctic. The simulated vegetation distribution (1961–1990) agreed well with a composite map of actual arctic vegetation. In the future (2051–2080), a poleward advance of the forest–tundra boundary, an expansion of tall shrub tundra, and a dominance shift from deciduous to evergreen boreal conifer forest over northern Eurasia were simulated. Ecosystems continued to sink carbon for the next few decades, although the size of these sinks diminished by the late 21st century. Hot spots of increased CH4 emission were identified in the peatlands near Hudson Bay and western Siberia. In terms of their net impact on regional climate forcing, positive feedbacks associated with the negative effects of tree-line, shrub cover and forest phenology changes on snow-season albedo, as well as the larger sources of CH4, may potentially dominate over negative feedbacks due to increased carbon sequestration and increased latent heat flux.},
author = {Zhang, Wenxin and Miller, Paul A and Smith, Benjamin and Wania, Rita and Koenigk, Torben and D{\"{o}}scher, Ralf},
doi = {10.1088/1748-9326/8/3/034023},
journal = {Environmental Research Letters},
number = {3},
pages = {34023},
publisher = {{\{}IOP{\}} Publishing},
title = {{Tundra shrubification and tree-line advance amplify arctic climate warming: results from an individual-based dynamic vegetation model}},
volume = {8},
year = {2013}
}
@article{Zhang2018d,
abstract = {Satellite-retrieved solar-induced chlorophyll fluorescence (SIF) has shown great potential to monitor the photosynthetic activity of terrestrial ecosystems. However, several issues, including low spatial and temporal resolution of the gridded datasets and high uncertainty of the individual retrievals, limit the applications of SIF. In addition, inconsistency in measurement footprints also hinders the direct comparison between gross primary production (GPP) from eddy covariance (EC) flux towers and satellite-retrieved SIF. In this study, by training a neural network (NN) with surface reflectance from the MODerate-resolution Imaging Spectroradiometer (MODIS) and SIF from Orbiting Carbon Observatory-2 (OCO-2), we generated two global spatially contiguous SIF (CSIF) datasets at moderate spatiotemporal (0.05° 4-day) resolutions during the MODIS era, one for clear-sky conditions (2000-2017) and the other one in all-sky conditions (2000-2016). The clear-sky instantaneous CSIF (CSIFclear-inst) shows high accuracy against the clear-sky OCO-2 SIF and little bias across biome types. The all-sky daily average CSIF (CSIFall-daily) dataset exhibits strong spatial, seasonal and interannual dynamics that are consistent with daily SIF from OCO-2 and the Global Ozone Monitoring Experiment-2 (GOME-2). An increasing trend (0.39 {\%}) of annual average CSIFall-daily is also found, confirming the greening of Earth in most regions. Since the difference between satellite-observed SIF and CSIF is mostly caused by the environmental down-regulation on SIFyield, the ratio between OCO-2 SIF and CSIFclear-inst can be an effective indicator of drought stress that is more sensitive than the normalized difference vegetation index and enhanced vegetation index. By comparing CSIFall-daily with GPP estimates from 40 EC flux towers across the globe, we find a large cross-site variation (c.v. Combining double low line 0.36) of the GPP-SIF relationship with the highest regression slopes for evergreen needleleaf forest. However, the cross-biome variation is relatively limited (c.v. Combining double low line 0.15). These two contiguous SIF datasets and the derived GPP-SIF relationship enable a better understanding of the spatial and temporal variations of the GPP across biomes and climate.},
author = {Zhang, Yao and Joiner, Joanna and {Hamed Alemohammad}, Seyed and Zhou, Sha and Gentine, Pierre},
doi = {10.5194/bg-15-5779-2018},
issn = {17264189},
journal = {Biogeosciences},
number = {19},
pages = {5779--5800},
title = {{A global spatially contiguous solar-induced fluorescence (CSIF) dataset using neural networks}},
volume = {15},
year = {2018}
}
@article{Zhang2020,
abstract = {The variability of methane emissions from wetlands in the tropics and northern temperate regions can explain more than 70{\%} of the interannual variation in global wetland methane emissions, which are largely driven by climate variability. We use climate reanalysis, remote sensing wetland area dataset and simulations from 11 land models contributing to Global Methane Budget to investigate the interannual variation and anomalies of wetland methane emissions in the Asian Monsoon region. Methane emissions in this region steadily increased over 2000–2012. However, abnormally low methane emissions were found in equatorial fully humid (Af), warm temperate winter dry (Cw), and warm temperate fully humid (Cf) Asian Monsoon climate sub-regions in 2008, 2009 and 2011, respectively. These spatially-shifting low emissions occurred simultaneously with observed wetland area shrinkage due to abnormally low precipitation. Interannual variability of wetland methane emissions in Asian Monsoon region are primarily driven by South Asian Monsoon system. However, the abnormally low emissions are related to strong La Ni{\~{n}}a events, and its accompanying effect of weakened East Asian Monsoon system and eastward Western Pacific subtropical high, which drives the shifting pattern of rainfall, and thus the spatial pattern of methane emission anomalies.},
author = {Zhang, Xiaoyan and Xu, Xiyan and Jia, Gensuo and Poulter, Benjamin and Zhang, Zhen},
doi = {10.1007/s00382-020-05219-0},
issn = {1432-0894},
journal = {Climate Dynamics},
number = {9},
pages = {4095--4107},
title = {{Hiatus of wetland methane emissions associated with recent La Ni{\~{n}}a episodes in the Asian monsoon region}},
url = {https://doi.org/10.1007/s00382-020-05219-0},
volume = {54},
year = {2020}
}
@article{Zhang2020a,
author = {Zhang, Liwei and Xia, Xinghui and Liu, Shaoda and Zhang, Sibo and Li, Siling and Wang, Junfeng and Wang, Gongqin and Gao, Hui and Zhang, Zhenrui and Wang, Qingrui and Wen, Wu and Liu, Ran and Yang, Zhifeng and Stanley, Emily H. and Raymond, Peter A.},
doi = {10.1038/s41561-020-0571-8},
issn = {1752-0894},
journal = {Nature Geoscience},
month = {may},
number = {5},
pages = {349--354},
title = {{Significant methane ebullition from alpine permafrost rivers on the East Qinghai–Tibet Plateau}},
url = {http://www.nature.com/articles/s41561-020-0571-8},
volume = {13},
year = {2020}
}
@article{Zhang2020b,
abstract = {Abstract Anthropogenic CO2 uptake drives ocean acidification and so decreases the calcium carbonate (CaCO3) saturation state ($\Omega$). Undersaturation of surface water with respect to aragonite-type CaCO3 was first reported for 2008 in the Canada Basin, preceding other open ocean basins. This study reveals interannual variation of $\Omega$ in the surface Canada Basin before and after 2008. A rapid decrease of $\Omega$ occurred during 2003–2007 at a rate of −0.09 year−1, 10 times faster than other open oceans. This was due to melting and retreat of sea ice, which diluted surface water and enhanced air-sea CO2 exchange. After 2007, $\Omega$ did not further decrease, despite increasing atmospheric CO2 and continued sea ice retreat. A weakened dilution effect from sea ice melt and stabilized air-sea CO2 disequilibrium state is the main reason for this stabilization of $\Omega$. Aragonite undersaturation has been observed for the last 11 years, and aragonite-shelled organisms may be threatened.},
author = {Zhang, Y and Yamamoto‐Kawai, M. and Williams, W.J.},
doi = {10.1029/2019GL086421},
issn = {0094-8276},
journal = {Geophysical Research Letters},
keywords = {Arctic Ocean,Beaufort Gyre,air-sea CO2 exchange,aragonite undersaturation state,ocean acidification,sea ice melt},
month = {feb},
number = {3},
pages = {e60119},
title = {{Two Decades of Ocean Acidification in the Surface Waters of the Beaufort Gyre, Arctic Ocean: Effects of Sea Ice Melt and Retreat From 1997–2016}},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL086421 https://onlinelibrary.wiley.com/doi/10.1029/2019GL086421},
volume = {47},
year = {2020}
}
@article{Zhao2019a,
abstract = {±30 ppbv. Over the full 2000–2016 time period, using a common state-of-the-art but nonoptimized emission scenario, the impact of [OH] changes tested here can explain up to 54 {\%} of the gap between model simulations and observations. This result emphasizes the importance of better representing OH abundance and variations in CH4 forward simulations and emission optimizations performed by atmospheric inversions.]]{\textgreater}},
author = {Zhao, Yuanhong and Saunois, Marielle and Bousquet, Philippe and Lin, Xin and Berchet, Antoine and Hegglin, Michaela I. and Canadell, Josep G. and Jackson, Robert B. and Hauglustaine, Didier A. and Szopa, Sophie and Stavert, Ann R. and Abraham, Nathan Luke and Archibald, Alex T. and Bekki, Slimane and Deushi, Makoto and J{\"{o}}ckel, Patrick and Josse, B{\'{e}}atrice and Kinnison, Douglas and Kirner, Ole and Mar{\'{e}}cal, Virginie and O'Connor, Fiona M. and Plummer, David A. and Revell, Laura E. and Rozanov, Eugene and Stenke, Andrea and Strode, Sarah and Tilmes, Simone and Dlugokencky, Edward J. and Zheng, Bo},
doi = {10.5194/acp-19-13701-2019},
issn = {1680-7324},
journal = {Atmospheric Chemistry and Physics},
month = {nov},
number = {21},
pages = {13701--13723},
publisher = {Copernicus Publications},
title = {{Inter-model comparison of global hydroxyl radical (OH) distributions and their impact on atmospheric methane over the 2000–2016 period}},
url = {https://acp.copernicus.org/articles/19/13701/2019/},
volume = {19},
year = {2019}
}
@article{Zhou2014,
abstract = {Anthropogenic global warming affects marine ecosystems in complex ways, and declining ocean oxygenation is a growing concern. Forecasting the geographical and bathymetric extent, rate, and intensity of future deoxygenation and its effects on oceanic biota, however, remains highly challenging because of the complex feedbacks in the Earth-ocean biota system. Information on past global warming events such as the Paleocene-Eocene Thermal Maximum (PETM, {\~{}}55.5 Ma), a potential analog for present and future global warming, may help in such forecasting. Documenting past ocean deoxygenation, however, is hampered by the lack of sensitive proxies for past oceanic oxygen levels throughout the water column. As yet no evidence has been presented for pervasive deoxygenation in the upper water column through expansion of oxygen minimum zones (OMZs). We apply a novel proxy for paleoredox conditions, the iodine to calcium ratio (I/Ca) in bulk coarse fraction sediment and planktonic foraminiferal tests from pelagic sites in different oceans, and compared our reconstruction with modeled oxygen levels. The reconstructed iodate gradients indicate that deoxygenation occurred in the upper water column in the Atlantic, Indian Oceans, and possibly the Pacific Ocean, as well during the PETM, due to vertical and potentially lateral expansion of OMZs.},
author = {Zhou, Xiaoli and Thomas, Ellen and Rickaby, Rosalind E M and Winguth, Arne M E and Lu, Zunli},
doi = {10.1002/2014PA002702},
isbn = {1944-9186},
issn = {08838305},
journal = {Paleoceanography},
keywords = {I/Ca,PETM,foraminifera,ocean deoxygenation},
month = {oct},
number = {10},
pages = {964--975},
title = {{I/Ca evidence for upper ocean deoxygenation during the PETM}},
url = {http://doi.wiley.com/10.1002/2014PA002702},
volume = {29},
year = {2014}
}
@article{Zhou2019,
abstract = {Compound extremes such as cooccurring soil drought (low soil moisture) and atmospheric aridity (high vapor pressure deficit) can be disastrous for natural and societal systems. Soil drought and atmospheric aridity are 2 main physiological stressors driving widespread vegetation mortality and reduced terrestrial carbon uptake. Here, we empirically demonstrate that strong negative coupling between soil moisture and vapor pressure deficit occurs globally, indicating high probability of cooccurring soil drought and atmospheric aridity. Using the Global Land Atmosphere Coupling Experiment (GLACE)-CMIP5 experiment, we further show that concurrent soil drought and atmospheric aridity are greatly exacerbated by land–atmosphere feedbacks. The feedback of soil drought on the atmosphere is largely responsible for enabling atmospheric aridity extremes. In addition, the soil moisture–precipitation feedback acts to amplify precipitation and soil moisture deficits in most regions. CMIP5 models further show that the frequency of concurrent soil drought and atmospheric aridity enhanced by land–atmosphere feedbacks is projected to increase in the 21st century. Importantly, land–atmosphere feedbacks will greatly increase the intensity of both soil drought and atmospheric aridity beyond that expected from changes in mean climate alone.},
author = {Zhou, Sha and {Park Williams}, A. and Berg, Alexis M. and Cook, Benjamin I. and Zhang, Yao and Hagemann, Stefan and Lorenz, Ruth and Seneviratne, Sonia I. and Gentine, Pierre},
doi = {10.1073/pnas.1904955116},
issn = {10916490},
journal = {Proceedings of the National Academy of Sciences},
keywords = {Compound extreme events,GLACE-CMIP5,Soil moisture,Vapor pressure deficit},
number = {38},
pages = {18848--18853},
pmid = {31481606},
title = {{Land–atmosphere feedbacks exacerbate concurrent soil drought and atmospheric aridity}},
volume = {116},
year = {2019}
}
@article{Zhu2016a,
abstract = {Global environmental change is rapidly altering the dynamics of terrestrial vegetation, with consequences for the functioning of the Earth system and provision of ecosystem services1,2. Yet how global vegetation is responding to the changing environment is not well established. Here we use three long-term satellite leaf area index (LAI) records and ten global ecosystem models to investigate four key drivers of LAI trends during 1982–2009. We show a persistent and widespread increase of growing season integrated LAI (greening) over 25{\%} to 50{\%} of the global vegetated area, whereas less than 4{\%} of the globe shows decreasing LAI (browning). Factorial simulations with multiple global ecosystem models suggest that CO2 fertilization eects explain 70{\%} of the observed greening trend, followed by nitrogen deposition (9{\%}), climate change (8{\%}) and land cover change (LCC) (4{\%}). CO2 fertilization eects explain most of the greening trends in the tropics, whereas climate change resulted in greening of the high latitudes and the Tibetan Plateau. LCC contributed most to the regional greening observed in southeast China and the eastern United States. The regional eects of unexplained factors suggest that the next generation of ecosystem models will need to explore the impacts of forest demography, dierences in regional management intensities for cropland andpastures,andother emerging productivity constraints such as phosphorus availability.},
author = {Zhu, Zaichun and Piao, Shilong and Myneni, Ranga B. and Huang, Mengtian and Zeng, Zhenzhong and Canadell, Josep G. and Ciais, Philippe and Sitch, Stephen and Friedlingstein, Pierre and Arneth, Almut and Cao, Chunxiang and Cheng, Lei and Kato, Etsushi and Koven, Charles and Li, Yue and Lian, Xu and Liu, Yongwen and Liu, Ronggao and Mao, Jiafu and Pan, Yaozhong and Peng, Shushi and Pe{\~{n}}uelas, Josep and Poulter, Benjamin and Pugh, Thomas A. M. and Stocker, Benjamin D. and Viovy, Nicolas and Wang, Xuhui and Wang, Yingping and Xiao, Zhiqiang and Yang, Hui and Zaehle, S{\"{o}}nke and Zeng, Ning},
doi = {10.1038/nclimate3004},
isbn = {1758-6798},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {aug},
number = {8},
pages = {791--795},
title = {{Greening of the Earth and its drivers}},
url = {https://www.nature.com/articles/nclimate3004 http://www.nature.com/articles/nclimate3004},
volume = {6},
year = {2016}
}
@article{Zickfeld2016b,
abstract = {Recent research has demonstrated that global mean surface air warming is approximately proportional to cumulative CO 2 emissions. This proportional relationship has received considerable attention, as it allows one to calculate the cumulative CO 2 emissions (‘carbon budget') compatible with temperature targets and is a useful measure for model inter-comparison. Here we use an Earth system model to explore whether this relationship persists during periods of net negative CO 2 emissions. Negative CO 2 emissions are required in the majority of emissions scenarios limiting global warming to 2 °C above pre-industrial, with emissions becoming net negative in the second half of this century in several scenarios. We find that for model simulations with a symmetric 1{\%} per year increase and decrease in atmospheric CO 2 , the temperature change ($\Delta$ T ) versus cumulative CO 2 emissions (CE) relationship is nonlinear during periods of net negative emissions, owing to the lagged response of the deep ocean to previously increasing atmospheric CO 2 . When corrected for this lagged response, or if the CO 2 decline is applied after the system has equilibrated with the previous CO 2 increase, the $\Delta$ T versus CE relationship is close to linear during periods of net negative CO 2 emissions. A proportionality constant—the transient climate response to cumulative carbon emissions (TCRE)− can therefore be calculated for both positive and net negative CO 2 emission periods. We find that in simulations with a symmetric 1{\%} per year increase and decrease in atmospheric CO 2 the TCRE is larger on the upward than on the downward CO 2 trajectory, suggesting that positive CO 2 emissions are more effective at warming than negative emissions are at subsequently cooling. We also find that the cooling effectiveness of negative CO 2 emissions decreases if applied at higher atmospheric CO 2 concentrations.},
author = {Zickfeld, Kirsten and MacDougall, Andrew H. and Matthews, H. Damon},
doi = {10.1088/1748-9326/11/5/055006},
issn = {1748-9326},
journal = {Environmental Research Letters},
language = {en},
month = {may},
number = {5},
pages = {055006},
publisher = {IOP Publishing},
title = {{On the proportionality between global temperature change and cumulative CO2 emissions during periods of net negative CO2 emissions}},
url = {http://stacks.iop.org/1748-9326/11/i=5/a=055006?key=crossref.636dc44f6dba4b8a51aeff076afe0be1 https://iopscience.iop.org/article/10.1088/1748-9326/11/5/055006},
volume = {11},
year = {2016}
}
@article{Zickfeld2013,
abstract = {This paper summarizes the results of an intercomparison project with Earth System Models of Intermediate Complexity (EMICs) undertaken in support of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). The focus is on long-term climate projections designed to 1) quantify the climate change commitment of different radiative forcing trajectories and 2) explore the extent to which climate change is reversible on human time scales. All commitment simulations follow the four representative concentration pathways (RCPs) and their extensions to year 2300. MostEMICs simulate substantial surface air temperature and thermosteric sea level rise commitment following stabilization of the atmospheric composition at year-2300 levels. The meridional overturning circulation (MOC) is weakened temporarily and recovers to near-preindustrial values in most models for RCPs 2.6-6.0. The MOC weakening is more persistent for RCP8.5. Elimination of anthropogenic CO2emissions after 2300 results in slowly decreasing atmospheric CO2concentrations. At year 3000 atmospheric CO2is still at more than half its year-2300 level in all EMICs forRCPs 4.5-8.5. Surface air temperature remains constant or decreases slightly and thermosteric sea level rise continues for centuries after elimination ofCO2emissions in allEMICs.Restoration of atmosphericCO2fromRCPto preindustrial levels over 100-1000 years requires large artificial removal of CO2from the atmosphere and does not result in the simultaneous return to preindustrial climate conditions, as surface air temperature and sea level response exhibit a substantial time lag relative to atmospheric CO2. {\textcopyright} 2013 American Meteorological Society.},
author = {Zickfeld, Kirsten and Eby, Michael and Weaver, Andrew J. and Alexander, Kaitlin and Crespin, Elisabeth and Edwards, Neil R. and Eliseev, Alexey V. and Feulner, Georg and Fichefet, Thierry and Forest, Chris E. and Friedlingstein, Pierre and Goosse, Hugues and Holden, Philip B. and Joos, Fortunat and Kawamiya, Michio and Kicklighter, David and Kienert, Hendrik and Matsumoto, Katsumi and Mokhov, Igor I. and Monier, Erwan and Olsen, Steffen M. and Pedersen, Jens O. P. and Perrette, Mahe and Philippon-Berthier, Gwena{\"{e}}lle and Ridgwell, Andy and Schlosser, Adam and {Schneider Von Deimling}, Thomas and Shaffer, Gary and Sokolov, Andrei and Spahni, Renato and Steinacher, Marco and Tachiiri, Kaoru and Tokos, Kathy S. and Yoshimori, Masakazu and Zeng, Ning and Zhao, Fang},
doi = {10.1175/JCLI-D-12-00584.1},
issn = {0894-8755},
journal = {Journal of Climate},
month = {aug},
number = {16},
pages = {5782--5809},
title = {{Long-term climate change commitment and reversibility: An EMIC intercomparison}},
url = {http://journals.ametsoc.org/doi/10.1175/JCLI-D-12-00584.1},
volume = {26},
year = {2013}
}
@article{Zickfeld2009,
abstract = {Avoiding "dangerous anthropogenic interference with the climate system" requires stabilization of atmospheric greenhouse gas concentrations and substantial reductions in anthropogenic emissions. Here, we present an inverse approach to coupled climate-carbon cycle modeling, which allows us to estimate the probability that any given level of carbon dioxide (CO2) emissions will exceed specified long-term global mean temperature targets for "dangerous anthropogenic interference," taking into consideration uncertainties in climate sensitivity and the carbon cycle response to climate change. We show that to stabilize global mean temperature increase at 2 degrees C above preindustrial levels with a probability of at least 0.66, cumulative CO2 emissions from 2000 to 2500 must not exceed a median estimate of 590 petagrams of carbon (PgC) (range, 200 to 950 PgC). If the 2 degrees C temperature stabilization target is to be met with a probability of at least 0.9, median total allowable CO2 emissions are 170 PgC (range, -220 to 700 PgC). Furthermore, these estimates of cumulative CO2 emissions, compatible with a specified temperature stabilization target, are independent of the path taken to stabilization. Our analysis therefore supports an international policy framework aimed at avoiding dangerous anthropogenic interference formulated on the basis of total allowable greenhouse gas emissions.},
author = {Zickfeld, Kirsten and Eby, Michael and Matthews, H Damon and Weaver, Andrew J},
doi = {10.1073/pnas.0805800106},
issn = {0027-8424},
journal = {Proceedings of the National Academy of Sciences},
month = {sep},
number = {38},
pages = {16129--16134},
pmid = {19706489},
publisher = {National Academy of Sciences},
title = {{Setting cumulative emissions targets to reduce the risk of dangerous climate change}},
url = {http://www.ncbi.nlm.nih.gov/pubmed/19706489 http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC2752604 http://www.pnas.org/cgi/doi/10.1073/pnas.0805800106},
volume = {106},
year = {2009}
}
@article{Zickfeld2015,
author = {Zickfeld, Kirsten and Herrington, Tyler},
doi = {10.1088/1748-9326/10/3/031001},
issn = {1748-9326},
journal = {Environmental Research Letters},
month = {mar},
number = {3},
pages = {031001},
publisher = {IOP Publishing},
title = {{The time lag between a carbon dioxide emission and maximum warming increases with the size of the emission}},
url = {http://stacks.iop.org/1748-9326/10/i=3/a=031001?key=crossref.4389d0372caa78e95690e42acaf82b13},
volume = {10},
year = {2015}
}
@article{Zickfeld2019,
author = {Zickfeld, Kirsten and Azevedo, Deven and Mathesius, Sabine and Matthews, H. Damon},
doi = {10.1038/s41558-021-01061-2},
issn = {1758-678X},
journal = {Nature Climate Change},
month = {jul},
number = {7},
pages = {613--617},
title = {{Asymmetry in the climate–carbon cycle response to positive and negative CO2 emissions}},
url = {http://www.nature.com/articles/s41558-021-01061-2},
volume = {11},
year = {2021}
}
@article{Zubkova2019,
abstract = {While several studies have reported a recent decline in area burned in Africa, the causes of this decline are still not well understood. In this study, we found that from 2002 to 2016 burned area in Africa declined by 18.5{\%}, with the strongest decline (80{\%} of the area) in the Northern Hemisphere. One third of the reduction in burned area occurred in croplands, suggesting that changes in agricultural practices (including cropland expansion) are not the predominant factor behind recent changes in fire extent. Linear models that considered interannual variability in climate factors directly related to biomass productivity and aridity explained about 70{\%} of the decline in burned area in natural land cover. Our results provide evidence that despite the fact that most fires are human-caused in Africa, increased terrestrial moisture during 2002–2016 facilitated declines in fire activity in Africa.},
author = {Zubkova, Maria and Boschetti, Luigi and Abatzoglou, John T. and Giglio, Louis},
doi = {10.1029/2019GL083469},
issn = {19448007},
journal = {Geophysical Research Letters},
number = {13},
pages = {7643--7653},
title = {{Changes in Fire Activity in Africa from 2002 to 2016 and Their Potential Drivers}},
volume = {46},
year = {2019}
}