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, which will be published March 16 in the online journal Environmental Research Letters, 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.