Rising temperatures mean large chunks of Africa are whipsawing between increasingly severe droughts and more frequent and intense cyclones, threatening staple foods for hundreds of millions of people. The International Monetary Fund says each increase of 1 degree Celsius correlates to a three-percentage-point reduction in agricultural output in developing countries. It forecasts crop yields in sub-Saharan Africa will decline by 5 to 17 percent by 2050, despite a rapidly growing population. Smallholder farmers are already struggling.