13. Impacts of Changes in Regional Rainfall-Distribution Patterns on Winter Agriculture in Israel

According to climate models, the steady accumulation of greenhouse gases in the atmosphere is expected to cause global warming and variations in precipitation distribution over the globe. Since 1750 the concentration of CO₂ has increased by 31%, currently rising at a rate of about 0.4% per year. The Intergovernmental Panel on Climate Change (Impacts adaptation and vulnerability, Cambridge University Press, Cambridge, 2001) estimates a consequential increase of 1.4–5.8°C in the global average surface temperature during the period between 1990 and 2100. During the twenty-first century, the average precipitation is expected to increase in most of the world. However, simulation models seem to concur that in the Mediterranean basin, rainfall is about to decline. Israel is located in the eastern part of the basin – an area with extraordinary sensitivity to climate changes due to the confluence of several different climates, particularly the cold, rainy European climate in the north and the subtropic African conditions in the south. Recent studies focusing on Israeli climate have identified an increase in the frequency of extreme temperatures, as well as in extreme weather events. Ben-Gai et al. (Theor Appl Appl Climatol, 6164, 163–177, 1999a) found considerable spatial variations in the annual precipitation distribution. We demonstrate in this chapter the impact of such change in the distribution on the winter agricultural sector in Israel.