Climate change to worsen drought, diminish corn yields in Africa.
Maize is the most widely harvested agricultural product in Africa and is grown by small farmers who rely heavily on rainwater rather than irrigation.
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.
“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.
Running the numbers To assess climate change’s impact on maize production, the researchers took a multimodel approach, working combinations of global climate model predictions into an open-source crop model that simulates crop yields over successive growing seasons.
An uncertain future By combining climate and crop models, the team simulated maize yields in Africa for the years 2030, 2050, and 2090, under two climate change scenarios in which global average annual temperatures would rise by 2 degrees or 4 degrees Celsius by 2100 under different greenhouse gas concentration trajectories.
Under the worst-case scenario, in which global temperatures will rise by 4 degrees Celsius, these models estimate the Sahel and southern Africa will experience widespread yield losses, with some grid cells showing losses of up to 50 percent.
Dale and her colleagues observed the climate models produced a much wider range of predictions — and therefore a higher degree of uncertainty — in the most arid regions of Africa.