Food securityClimate change to worsen drought, diminish corn yields in Africa
Nearly 25 percent of the world’s malnourished population lives in sub-Saharan Africa, where more than 300 million people depend on corn, or maize, as their main food source. Maize is the most widely harvested agricultural product in Africa and is grown by small farmers who rely heavily on rainwater rather than irrigation. The crop is therefore extremely sensitive to drought, and since 2015 its production has fallen dramatically as a result of record-setting drought conditions across southern and eastern Africa.
Nearly 25 percent of the world’s malnourished population lives in sub-Saharan Africa, where more than 300 million people depend on corn, or maize, as their main food source. Maize is the most widely harvested agricultural product in Africa and is grown by small farmers who rely heavily on rainwater rather than irrigation. The crop is therefore extremely sensitive to drought, and since 2015 its production has fallen dramatically as a result of record-setting drought conditions across southern and eastern Africa.
Now MIT scientists have found that climate change will likely further worsen drought conditions in parts of the continent, dramatically reshaping the production of maize throughout sub-Saharan Africa as global temperatures rise over the next century.
In a paper published online this week in the journal Earth’s Future, the researchers report that, if the world’s average temperatures rise by 4 degrees Celsius by the year 2100, much of southern Africa and the Sahel region just south of the Sahara desert — regions that contribute a significant portion of Africa’s maize production — will experience increased aridity, which in turn is predicted to decrease maize crop yields in some nations by over 20 percent.
“[Maize] is a relatively drought-sensitive crop in a region where agricultural production is mostly rainfed,” says lead author Amy Dale, a postdoc in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). “If under climate change we have changes in temperature and precipitation, this is arguably one of the worst areas of the world where we’re going to see really negative impacts on crop production and malnourished populations.”
The researchers’ analysis also shows that climate change’s impact is less certain for the most arid regions of sub-Saharan Africa including the semiarid regions that produce over 40 percent of sub-Saharan African maize.
Kenneth Strzepek, a co-author on the paper and research scientist in MIT’s Joint Program on the Science and Policy of Global Change, says the study’s results provide a map for how agricultural conditions will change in the next century, as well as where climate change’s impact is still less clear. All this information, he says, is essential for government planners who aim to build up Africa’s economy and infrastructure.
