Warmer temperatures by the end of the century will reduce corn yields worldwide. The study also shows dramatic increases in the variability of corn yields from one year to the next and the likelihood of simultaneous low yields across multiple high-producing regions, which could lead to price hikes and global shortages. Corn, or maize, is the most widely grown crop in the world. Used in food, cooking oil, industrialized foods, livestock feed, and even automobile fuel, the crop is one that both rich and poor people rely upon.