National Academy of Sciences showed that warmer temperatures by the end of this century may increase the likelihood of simultaneous low yields across multiple high-producing regions, which could lead to price hikes and global shortages. The research led by the University of Washington (UW) showed dramatic increases in the variability of corn yields from one year to the next. Corn, the most widely grown crop in the world, is used in food, cooking oil, industrialized foods, livestock feed and even automobile fuel. While most rice is used domestically, corn is traded on international markets. Four countries, the United States, Brazil, Argentina and Ukraine account for 87 percent of global corn exports, with China mostly producing for domestic use.