Consequences of Climate Change for Agricultural Production

Climate plays a major role in determining the yield levels, the year-to-year variability and the spatial patterns of global agriculture. Agriculture is sensitive to short term changes in weather and to seasonal, annual and longer term variations in climate. Over the long term, agriculture is able to tolerate moderate variations about the climatic mean. Longterm marked changes in temperature, precipitation, and solar radiation will have an effect on the productivity of crop and livestock agriculture. Climate change will also have economic effects on agriculture, including changes in farm profitability, prices, supply, demand, trade, and regional comparative advantages. The magnitude and geographical distribution of such climateinduced changes may affect our ability to expand food production as required to feed a population of more than 10000 million people projected for the middle of the next century. Climate change could thus have far-reaching effects on patterns of trade among nations, development, and food security. The world’s forest estate has declined significantly in both area and quality in recent decades. The major causes of this decline are deforestation and air pollution, with climate change, storms and fires aggravating the situation. Because average temperatures are expected to rise more near the north and south poles than near the equator, the shift in climate zones will be more pronounced at higher latitudes. In the mid latitude regions (450 to 600), present temperature zones could shift by 150-550 km. Since each of today’s latitudinal climate belts are optimal for particular crops, such shifts could strongly affect agricultural and livestock production. Efforts to shift crops poleward in response could be limited by the inability of soil types in the new climate zones to support intensive agriculture as practised today in the main producer countries. The impact on crop yields and productivity will vary considerably. Added heat stress, shifting m