Potential yields of winter crops are expected to increase, especially in central and southern Europe, assuming that neither precipitation nor irrigation are limiting and that water-use efficiency increases with the ambient atmospheric concentration of CO 2 . Increasing spring temperatures would extend suitable zones for most summer crops. Summer crop yield increases are possible in central and eastern Europe, though decreases are possible in western Europe. Decreases in precipitation in southern Europe would reduce crop yields and make irrigation an even larger competitor to domestic and industrial water use. Along with potential crop yields, farmer adaptation, agricultural policy, and world markets are important factors in the economic impact of climate change on the agricultural sector.
Coastal zones are ecologically and economically important.
Settlement and economic activity have reduced the resilience and adaptability of coastal systems to climate variability and change, as well as to sea-level rise. Some coastal areas already are beneath mean sea level, and many others are vulnerable to storm surges. Storm surges, changes in precipitation, and changes in wind speed and direction add to the concern of coastal planners. In general, major economic and social impacts can be contained with relatively low investment. This is not true, however, for a number of low-lying urban areas vulnerable to storm surges, nor for ecosystems particularly coastal wetlands which may be even further damaged by protective measures.