Author: Jeff McMahon | Published: September 1, 2017
Increased temperatures from climate change will reduce yields of the four crops humans depend on most—wheat, rice, corn and soybeans—and the losses have already begun, according to a new meta-study by an international team of researchers.
Humans depend for two thirds of their calories on these four staple crops, but yields of wheat are expected to decrease by 6%, rice by 3.2%, maize by 7.4%, and soybean by 3.1%.
“By combining four different methods, our comprehensive assessment of the impacts of increasing temperatures on major global crops shows substantial risks for agricultural production, already stagnating in some parts of the world,” the scientists say in the study, which appears in the latest issue of the Proceedings of the National Academy of Sciences.
“Yield increase has slowed down or even stagnated during the last years in some parts of the world, and further increases in temperature will continue to suppress yields, despite farmers’ adaptation efforts.” The study, led by Chuang Zhao of Peking University, cites three other studies documenting declines in crop yields in Europe, Africa, India, China, Central and South America and other regions.
The study of studies was conducted by scientists in China, Germany, Belgium, Italy, France, Spain, The Philippines, and the United States, including the University of Florida, Stanford University, the University of Chicago, and Columbia University in New York. They hoped to settle a question that seemed to have produced conflicting results in the many studies they reviewed: what are the effects on crop yields of temperature increases from anthropogenic climate change?