Bassirou Sani Boubacar Gaoh has spent the last decade trying to figure out how the plants feeding millions across Niger can better withstand the unpredictability of a warming planet. Extreme heatwaves and severe droughts that alternate with heavy rainfall and flash floods are imperiling the many millet, rice, and sorghum farms throughout the Sahel region, where temperatures have risen much faster than the global average. Yet the biggest threat …