Impoverished farmers in South Asia and southern Africa could face growing food shortages due to climate change within just 20 years, a new study says.
Increasing levels of greenhouse gases, including carbon dioxide, are heating up the planet, with droughts and shifting rainfall patterns predicted for many parts of the world.
“The majority of the world’s one billion poor depend on agriculture for their livelihoods,” said the lead author of the new study, David Lobell of Stanford University.
“Unfortunately, agriculture is also the human enterprise most vulnerable to changes in climate.”
Climate change will affect some places more than others, so Lobell and colleagues focused on 12 regions where most of the world’s impoverished live and the crops that the poor tend to grow and eat in those places.
They identified two hot spots—South Asia and southern Africa—where higher temperatures and drops in rainfall could cut yields of the main crops people grow there.
“We were surprised by how much, and how soon, these regions could suffer if we don’t adapt,” said study co-author Marshall Burke, also at Stanford.
Corn, Wheat at Risk
The researchers used computer models to predict changes in temperature and rainfall as the planet warms.
Most of the 12 regions were predicted to warm up about 1.8 degrees Fahrenheit (1 degree Celsius) by 2030—about the same amount of warming that Earth as a whole experienced over the 20th century.
“To identify which crops in which regions are most under threat by 2030, we combined projections of climate change with data on what poor people eat, as well as past relationships between crop harvests and climate variability,” Lobell said.
The predictions from the various climate models often didn’t agree on rainfall changes, he noted. But the overall analysis did suggest that southern Africa and South Asia were two spots where hotter temperatures and lack of water are most likely to stress crops.