Volcanoes, cloud cover, regional characteristics and changing of atmospheric components cannot, if they ever will, be successfully factored into an accurate climate model. From the perspective of food security, the stability of agricultural production is as important, if not more so, than the magnitude of output. Extremes in weather, rather than averages, affect agriculture. Both crops and livestock are sensitive to weather over relatively short periods of time. Annual averages of temperature and rainfall do not convey short term deficiencies, which differences impact both the volume and stability of food output.
History reveals that for food production, warming is better than cooling.
Of all the natural climate hazards, drought is that which farmers fear most. The lack of water is the single greatest impediment to plant growth and global food production. This is illustrated by the fact that today, irrigated cropland-about 17 percent of the world's total, produces one third of the agricultural output. For the United States, the 12 percent of the cultivated farm land that is irrigated, accounts for 37 percent of crop production. For the world, it is more than 65 percent.