By JR on Thursday, May 26, 2011
Computer models at Stanford University have just “told” us that man-made global warming has already sapped some of the yield potential from our food crops. They say wheat yields would have been 5.5 percent higher since 1980 without the earthly warming; corn yields would have been 3.8 percent higher.
Stanford’s computers apparently didn’t tell their programmers that U.S. corn yields have actually risen by more than 60 percent since 1980 - during a period when they were supposedly hampered by too much heat. Wheat yields rose 14 percent, aided by higher levels of CO2, which act like fertilizer for plants.
In fact, if you’re worried about global food production, don’t pay much attention to this study. Recall that our recent temperatures have recently been about the same as in 1980 and 1981. Net warming since 1940 is only about 0.2 degrees C. Those are not numbers that would frighten a plant breeder, who understands that all of the wild species have proven they can handle climate changes of at least 4 degrees C with little problem.
Computer models only work if they have been programmed with adequate information. The computerized climate models, for example, claim that the earth’s recent warming is “unprecedented.” However, nobody told the computers about the Medieval Warming (950–1200 AD) and the Roman Warming (200 BC– 600 AD), both warmer than today.
Moreover, our corn, wheat, and rice are all originally tropical crops:
* Corn originated in the hot, wet lowlands of Mexico - and didn’t get cold-tolerant enough for the Corn Belt until after 4,000 years of careful seed selection by many generations of farmers.
* Wheat was native to the Fertile Crescent - the hot, dry regions of Palestine and Israel. In the Punjab today, it tolerates summer temperatures as high as 100 degrees F.
* Rice evolved in the Yangtze River Valley of China, where summer temperatures also rise above 100 degrees F. But rice thrives, too, in Manchuria at summer temperatures of only 80 degrees.
Drought, not temperature, has been the real enemy of food production, around the world and over time. The big droughts have come more often during the “little ice ages” than during the predominantly good weather of the global warmings. The warmings have been the good times, for humans, crops, and wildlife.
Over the last 4000 years, the region of Iraq has had droughts as long as 300 years during “little ice ages.” Its cities and fields were abandoned, left to nomadic shepherds. Egypt suffered only 8 percent of its Nile floods below-normal during the Medieval Warming - but 38 percent below-normal floods during the Little Ice Age. Closer to home, California had two century-long droughts during the Medieval Warming. Perhaps the computers should be programmed to look for shifting rain patterns and not worry about a 0.2 degree shift in temperature.
The real food challenge? The world will need to nearly double its farm output in the next 40 short years, to meet a last, moderate increase in population—and a huge surge in affluence. The rising incomes will have everybody in the world bidding for a high-quality diet. We’ll need all the technology research can muster, including drought-resistant crops. Otherwise, food prices will soar and wildlife habitat will disappear under innumerable plows