Working Group II: Impacts, Adaptation and Vulnerability

Other reports in this collection Long-Term Adaptations

Long-term adaptations refer to major structural changes to overcome adversity caused by climate change. These may include:

  • Changes in land use result from the differential response of crops to climate change. Studies reported by Parry et al. (1988) for central Europe show an “optimal land use” in which the area cultivated with winter wheat, maize, and vegetables increases while the allocation to spring wheat, barley, and potato, decreases. Changes in land allocation also may be used to stabilize production. In this case, crops with high interannual variability in production (e.g., wheat) may be replaced by crops with lower productivity but more stable yields (e.g., pasture).
  • Biotechnology offers another possibility to adapt to stresses (heat, water, pests and disease, etc.) that are enhanced by climate change by allowing development of “designer cultivars” (Goodman et al., 1987)—considering strictly the principles of biosafety to avoid possible negative impacts of this technique. Species that have not been used previously for agricultural purposes may be identified and others already identified may be more quickly brought into use.
  • Crop substitution also may be useful for conservation of soil moisture. Some crops use a low amount of water and are more water- and heat-resistant, so they tolerate dry weather better than others do. For example, sorghum is more tolerant of hot and dry conditions than maize.
  • Microclimate modification may be used to improve WUE in agriculture. Windbreaks, for example, reduce evaporative demand from the plants they shelter. Sheltered plants remain better hydrated and thus are better able to carry out photosynthesis (Rosenberg, 1979). A wide array of intercropping, multi-cropping, relay cropping, and other techniques provide greater production per unit area occupied and can be useful to improve WUE. Irrigation efficiency can be improved considerably with new land-field techniques (laser-leveling of fields, minimum tillage, chiseling compacted soils, stubble mulching, etc.) or new management strategies (irrigation scheduling, monitoring soil moisture status, etc.) (Kromm and White, 1990).
  • Changes in farming systems may be necessary in some areas for farming to remain viable and competitive. Specialized arable farms with production of vegetables, cereals, seed crops, fruits, and other crops often have only a few species on the farm, depending on soil and climate conditions. These specialized farms, especially dairying and arable, may be more affected by climate change than mixed farms. Mixed farms with both livestock and arable production have more options for change and thus larger resilience to change in the environment.

Studies on adapting farming systems to climate change need to consider all of the agronomic decisions made at the farm level (Kaiser et al., 1993). Economic considerations are very important in this context (Antle, 1996). Results of farm-level analyses on the impacts of climate change generally have shown a large reduction in adverse impacts when adaptation is fully implemented. However, this will result in land-use changes (Parry et al., 1999).

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