Over a span of two decades, warming temperatures have caused annual losses of roughly $5 billion for major food crops, according to a new study by researchers at the Carnegie Institution and Lawrence Livermore National Laboratory. From 1981-2002, warming reduced the combined production of wheat, corn, and barley-cereal grains that form the foundation of much of the world’s diet-by 40 million metric tons per year. The study demonstrates that this decline is due to human-caused increases in global temperatures. ‘Most people tend to think of climate change as something that will impact the future,’ said Christopher Field, co-author on the study and director of Carnegie’s Department of Global Ecology in Stanford, Calif. ‘But this study shows that warming over the past two decades has already had real effects on global food supply.’ The study is the first to estimate how much global food production has already been affected by climate change. Field and David Lobell, lead author of the study and a researcher at Lawrence Livermore National Laboratory, compared yield figures from the Food and Agriculture Organization with average temperatures and precipitation in the major growing regions. They found that, on average, global yields for several […]