REPORTS - SPECIAL REPORTS
IPCC Special Report on Emissions Scenarios
Appendix XI: Glossary of Terms
The act or process of establishing a forest,
especially on land not previously forested.
Energy derived from non-fossil fuel sources.
Emissions of greenhouse gases (GHGs) associated
with human activities. These include burning of fossil fuels for
energy, deforestation, and land-use changes.
Annex I Countries
Annex I to the Climate Convention (UNFCCC) lists
all the countries in the Organization of Economic Cooperation
and Development (OECD), plus countries with economies in transition,
Central, and Eastern Europe (excluding the former Yugoslavia and
Albania). By default the other countries are referred to as Non-Annex
I countries. Under Article 4.2 (a&b) of the Convention, Annex
I countries commit themselves specifically to the aim of returning
individually or jointly to their 1990 levels of GHG emissions
by the year 2000.
Annex II Countries
Annex II to the Climate Convention lists all
countries in the OECD. Under Article 4.2 (g) of the Convention,
these countries are expected to provide financial resources to
assist developing countries comply with their obligations such
as preparing national reports. Annex II countries are also expected
to promote the transfer of environmentally sound technologies
to developing countries.
Annex B Countries
Annex B in the Kyoto Protocol lists those developed
countries that have agreed to a target for their GHG emissions,
including those in the OECD, Central and Eastern Europe, and the
Russian Federation. Not quite the same but similar to Annex I,
which also includes Turkey and Belarus, while Annex B includes
Croatia, Monaco, Liechtenstein, and Slovenia.
A projected level of future emissions against
which reductions by project activities could be determined.
A common year for calculating emission inventories
or to begin model simulations for future scenarios.
A fuel produced from dry organic matter or combustible
oils produced by plants. Examples of biofuel include alcohol (from
fermented sugar), black liquor from the paper manufacturing process,
wood, and soybean oil.
The total dry organic matter or stored energy
content of living organisms. Biomass can be used for fuel directly
by burning it (e.g., wood), indirectly by fermentation to an alcohol
(e.g., sugar), or by extraction of combustible oils (e.g., soybeans).
The natural processes that influence the exchange
of carbon (in the form of carbon dioxide (CO2
and organic compounds, etc.) among the atmosphere, ocean, and
terrestrial systems. Major components include photosynthesis,
respiration, and decay between atmospheric and terrestrial systems
(approximately 100 billion tons/year (gigatons)); thermodynamic
invasion and evasion between the ocean and atmosphere, operation
of the carbon pump and mixing in the deep ocean (approx. 90 billion
tons/year). Deforestation and fossil fuel burning releases approximately
7 Gt into the atmosphere annually. The total carbon in the reservoirs
is approximately 2000 Gt in land biota, soil, and detritus, 750
Gt in the atmosphere, and 38,000 Gt in the oceans. (Figures from
IPCC WGI Scientific Assessment 1990.)
A naturally occurring gas, CO2
also a by-product of burning fossil fuels and biomass, as well
as land-use changes and other industrial processes. It is the
principal anthropogenic GHG that affects the earth's temperature.
It is the reference gas against which other GHGs are measured
and therefore has a "Global Warming Potential" (GWP) of 1.
The long-term storage of carbon or CO2
in the forests, soils, ocean, or underground in depleted oil and
gas reservoirs, coal seams, and saline aquifers. Examples include
the separation and disposal of CO2
from flue gases
or processing fossil fuels to produce H2
- and CO2
fractions, and the direct removal of CO2
from the atmosphere
through land use change, afforestation, reforestation, ocean fertilization,
and agricultural practices to enhance soil carbon.
Natural or man-made systems that absorb CO2
from the atmosphere and store them. Trees, plants, and the oceans
all absorb CO2
and, therefore, are carbon sinks.
Chlorofluorocarbons (CFCs) are GHGs covered
under the 1987 Montreal Protocol and used for refrigeration, air
conditioning, packaging, insulation, solvents, or aerosol propellants.
As they are not destroyed in the lower atmosphere, CFCs drift
into the upper atmosphere where, given suitable conditions, they
break down ozone. These gases are being replaced by other compounds,
including hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons
(HFCs), which are GHGs covered under the Kyoto Protocol.
Climate Change (UNFCCC definition)
A change of climate which is attributed directly
or indirectly to human activity that alters the composition of
the global atmosphere and that is in addition to natural climate
variability over comparable time periods.
See "UN Framework Convention on Climate Change".
Large and complex computer programs used to
mathematically simulate global climate. They are based on mathematical
equations derived from our knowledge of the physics that governs
the earthatmosphere system.
The use of waste heat from electric generation,
such as exhaust from gas turbines, for either industrial purposes
or district heating.
Sequence of actions necessary to achieve market
entry and general market competitiveness of new innovative technologies,
processes, and products.
Conference of the Parties (COP)
The supreme body of the UN Framework Convention
on Climate Change (UNFCCC), comprises countries that have ratified
or acceded to the Framework Convention on Climate Change. The
first session of the Conference of the Parties (COP-1) was held
in Berlin in 1995, COP-2 in Geneva 1996, COP-3 in Kyoto 1997,
and COP-4 in Buenos Aires. COP-5 will be held in Bonn.
See "Carbon Dioxide".
A criterion that specifies that a technology
or measure delivers a good or service at equal or lower cost than
current practice, or the lowest cost alternative for the achievement
of a given target.
A decrease in the specific carbon content of
primary energy or of fuels.
The removal of forest stands by cutting and
burning to provide land for agricultural purposes, residential
or industrial building sites, roads, etc., or by harvesting the
trees for building materials or fuel.
Policies and programs designed to reduce consumer
demand for electricity and other energy sources while maintaining
(or even increasing) the services the energy use renders. It helps
to reduce the need for constructing new power facilities.
A decrease in the material intensity of economic
activity in general, or of individual production processes and
The portion of technical potential for GHG emissions
reductions or energy efficiency improvements that could be achieved
cost-effectively in the absence of market barriers. The achievement
of market potential requires additional policies and measures
to break down market barriers.
The release of GHGs and/or their precursors
into the atmosphere over a specified area and period of time.
The SRES Scenarios are grouped into four categories
of cumulative CO2
emissions (all sources) between 1990
and 2100: low, medium-low, medium-high, and high emissions. Each
category contains scenarios with a range of different driving
forces yet similar cumulative emissions. See also "(Scenario)
A level of emission that under law may not be
This is the ratio of energy consumption to economic
or physical output. At the national level, energy intensity is
the ratio of total domestic primary energy consumption or final
energy consumption to gross domestic product or physical output.
See 'UN Framework Convention on Climate Change'.
Energy supplied that is available to the consumer
to be converted into useful energy (e.g. electricity at the wall
Carbon-based fuels, including coal, oil, and
natural gas and their derived fuels such as gasoline, synthesis
gas from coal, etc.
Policy designed to reduce CO2
by requiring electric utilities or consumers to switch from high-carbon
to low- carbon fuels (e.g. from coal to gas).
See "Greenhouse Gases".
GHG Reduction Potential
Possible reductions in emissions of greenhouse
gasses (quantified in terms of absolute reductions or in percentages
of baseline emissions) that could be achieved through the use
of technologies and measures.
The hypothesis that the earth's temperature
is being increased, in part, because of emissions of GHGs associated
with human activities, such as burning fossil fuels, biomass burning,
cement manufacture, cow and sheep rearing, deforestation, and
other land-use changes.
Global Warming Potential
A measurement technique to define the relative
contribution of each GHG to atmospheric warming. A GWP can only
be calculated for specified time horizons (e.g. 20 to 500 years)
and for given GHG concentration levels (e.g. current). Both direct
and indirect effects are considered. (Indirect effects include
changes in atmospheric chemistry such as ozone formation and changes
in stratospheric water vapor.) CO2
has been assigned
a GWP of 1, against which all other GHGs are compared. For example,
) has a GWP that is currently estimated
to be about 21 times greater than that of CO2
a 100 year time horizon, and thus CH4
has a GWP of
21. (Note that in the economic literature GWP usually denotes
gross world product, referrred to as global GDP in this report.)
The trapping of heat by an envelope of naturally
occurring heat-retaining gases (water vapour, CO2
nitrous oxide (N2
, and ozone) that
keeps the earth about 30°C (60°F) warmer than if these
gases did not exist.
Gases in the earth's atmosphere that absorb
and re-emit infrared radiation. These gases occur through both
natural and human-influenced processes. The major GHG is water
vapour. Other GHGs include CO2
, ozone, and CFCs.
The provision of emission or socio-economic
activity data in spatially highly explicit form.
See "Global Warming Potential".
A procedure to ease comparability of model results
by adopting common (exogenous) input assumptions. Through harmonization,
differences in emissions outcomes resulting from differences in
model input assumptions (e.g. exogenous population growth) can
be separated from differences that arise from different internal
model parametrizations (e.g. of the dynamics of technological
change). The scenarios reported here can be classified into three
categories: "fully harmonized" scenarios share population, GDP,
and final energy use assumptions at the level of the four SRES
regions (and hence also at the global level) between 1990 and
2100 within prespecified bounds. "Globally harmonized" scenarios
share global population and GDP assumptions at the global level
for the 1990 to 2100 period within prespecified bounds (deviations
in one 10-year interval are not considered). "Other scenarios"
have adopted alternative assumptions for population and GDP than
the ones suggested for scenario harmonization.
HFCs are among the six GHGs to be curbed under
the Kyoto Protocol. They are produced commercially as a substitute
for CFCs. HFCs are used largely in refrigeration and semi-conductor
manufacturing. Their GWPs range from 1300 to 11,700 times that
(over a 100 year time horizon), depending on
A scenario that is illustrative for each of
the six scenario groups reflected in the Summary for Policymakers
of this report. They include four revised "scenario markers" for
the scenario groups A1B, A2, B1 and B2, and two additional scenarios
for the A1FI and AIT groups. All scenario groups are equally sound.
See also "(Scenario) Groups" and "(Scenario) Markers".
Intergovernmental Organization (IGO)
Organizations constituted of governments. Examples
include the World Bank, the OECD, and the International Civil
Aviation Organization. The UNFCCC allows accreditation of these
IGOs to attend the negotiating sessions.
International Energy Agency (IEA)
Paris-based organization formed in 1973 by the
major oil-consuming nations to manage future oil supply shortfalls.
International Institute for Applied Systems
Non-governmental, international, interdisciplinary
research institute located in Laxenburg, Austria. IIASA is supported
by the Academy of Sciences and similar learned societies from
15 countries. Its research focuses on the human dimensions of
Kyoto Mechanisms (formerly known as Flexibility
Economic mechanisms based on market principles
that Parties to the Kyoto Protocol can use in an attempt to lessen
the potential economic impacts of GHG emission-reduction requirements.
They include Joint Implementation (Article 6), the Clean Development
Mechanisms (Article 12), and Emissions Trading (Article 17).
The Protocol, drafted during the Berlin Mandate
process, that, on entry into force, would require countries listed
in its Annex B (developed nations) to meet differentiated reduction
targets for their GHG emissions relative to 1990 levels by 20082012.
It was adopted by all Parties to the Climate Convention in Kyoto,
Japan, in December 1997.
See "(Scenario) Marker".
The share of a given market that is provided
by a particular good or service at a given time.
Market Potential (or Currently Realizable Potential)
The portion of the economic potential for GHG
emissions reductions or energy efficiency improvements that could
be achieved under existing market conditions, assuming no new
policies and measures.
Actions that can be taken by a government or
a group of governments, often in conjunction with the private
sector, to accelerate the use of technologies or other practices
that reduce GHG emissions.
One of the six GHGs to be mitigated under the
Kyoto Protocol, it has a relatively short atmospheric lifetime
of 10 ± 2 years. Primary sources of CH4
coal mines, paddy fields, natural gas systems, and livestock (e.g.,
cows and sheep). It has a GWP of 21 (100 year
A formal representation of a system that allows
quantification of relevant system variables and simulation of
systems' behavior, e.g. the implications on future GHG emissions
of alternative demographic, economic and technological developments
International agreement under the UN which entered
into force in January 1989 to phase out the use of ozone-depleting
compounds such as CFCs, methyl chloroform, carbon tetrachloride,
and many others.
See "Non-Governmental Organization".
One of the six GHGs to be curbed under the Kyoto Protocol,
O is generated by burning fossil fuels and the manufacture
of fertilizer. It has a GWP 310 times that of CO2
year time horizon).
Non-Annex I Parties
The countries that have ratified or acceded
to the UNFCCC that are not included in Annex I of the Convention.
Non-Annex B Parties
The countries that are not included in the Annex
B list of developed nations in the Kyoto Protocol.
Non-Governmental Organization (NGOs) include
registered non-profit organizations and associations from business
and industry, environmental groups, cities and municipalities,
academics, and social and activist organizations.
Actions that result in GHG limitations and abatement,
and that also make good environmental and economic sense in their
) in the troposphere, or
lower part of the atmosphere, can be a constituent of smog and
acts as a GHG. It is created naturally and also by reactions in
the atmosphere that involve gases resulting from human activities,
including nitrogen oxides (NOx
), from motor vehicles
and power plants. The Montreal Protocol seeks to control chemicals
that destroy ozone in the stratosphere (upper part of the atmosphere),
where the ozone absorbs ultra-violet radiation.
See "Policies and Measures".
Among the six GHGs to be abated under the Kyoto
Protocol. Perfluorocarbons (PFCs) are a by-product of aluminum
smelting and uranium enrichment. They also are the replacement
for CFCs in manufacturing semiconductors. The GWP of PFCs is 65009200
times that of CO2
(100 year time horizon).
Policies and Measures
In UNFCCC parlance, policies are actions that
can be taken and/or mandated by a government often in conjunction
with business and industry within its own country, as well as
with other countries to accelerate the application and
use of successful measures to curb GHG emissions. Measures are
technologies, processes, and practices used to implement policies
that, if employed, would reduce GHG emissions below anticipated
future levels. Examples might include carbon or other energy taxes,
standardized fuel efficiency standards for automobiles, etc. "Common
and co-ordinated" or "harmonized" policies refer to those adopted
jointly by Parties. (This could be by region, such as the European
Union (EU), or by countries that comprise a given classification,
for example, all Annex I nations.)
From the UN Framework Convention on Climate
Change (Article 3): Parties should take precautionary measures
to anticipate, prevent or minimize the causes of climate change
and mitigate its adverse effects. Where there are threats of serious
or irreversible damage, lack of full scientific certainty should
not be used as a reason for postponing such measures taking into
account that policies and measures to deal with climate change
should be cost-effective so as to ensure global benefits at the
lowest possible cost.
Energy embodied in natural resources (e.g.,
coal, crude oil, sunlight, uranium) that has not undergone any
anthropogenic conversion or transformation.
Quantified Emissions Limitations and Reductions
Abbreviated to QELROs, these are the GHG emissions
reduction commitments made by developed countries listed in Annex
B of the Protocol. (See also "Targets and Timetables".)
Rules or codes enacted by governments that mandate
product specifications or process performance characteristics.
Energy sources that are, within a short timeframe
relative to the earth's natural cycles, sustainable, and include
non-carbon technologies such as solar energy, hydropower, and
wind as well as carbon-neutral technologies such as biomass.
Research, Development, and Demonstration
Scientific/technical research and development
of new production processes or products, coupled with analysis
and measures that provide information to potential users regarding
the application of the new product or process; demonstration tests,
and feasibility of applying these products processes via pilot
plants and other pre-commercial applications.