African Corn Faces Threat From Even Moderate Warming, Study Shows

A review of crop trial data from thousands of sites across Africa shows that a temperature increase of 1 degree C (1.8 F) could cause declines in corn harvests in two-thirds of the continent’s maize-growing regions. Drawing on previously unstudied data from 20,000 trials of corn yields across Africa from 1999 to 2007, an international team of researchers found that the longer corn crops are exposed to temperatures above 30 degrees C (86 F), the more yields decline. And under drought conditions, the researchers found that more than 75 percent of corn-growing regions suffered yield declines of at least 20 percent as temperatures rose 1 degree C. Researchers from the International Maize and Wheat Improvement Center, reporting in the journal Nature Climate Change, said the results surprised them because maize was assumed to be among the more heat-tolerant crops. The researchers reached their conclusions after gathering data from the 20,000 trial sites and then comparing it with temperature and rainfall data. They said the results show that corn, a staple crop for many Africans, could suffer significant yield declines if, as predicted, higher temperatures and drought impact Africa in the future.