Half the world’s population could face severe food shortages by the end of the century as rising temperatures are predicted to rob yields of rice and maize by 20 to 40% in tropical regions–so says a study in the journal Science.

“The stress on global food production from temperatures alone is going to be huge, and that doesn’t take into account water supplies stressed by the higher temperatures,” said David Battisti, at the University of Washington, who led the study.

Given that prediction, and given how precision technology is redefining the efficiency of how we grow crops–doesn’t it make sense that US farmers continue to feed even more of the world?

The tropics and subtropics, which stretch from the southern US to northern Argentina and southern Brazil, from northern India and southern China to southern Australia, and cover all of Africa, are currently home to 3 billion people. Future temperature rises are expected to have a greater impact in the tropics because the crops grown there are less resilient to changes in climate.

“When all the signs point in the same direction, and in this case it’s a bad direction, you pretty much know what’s going to happen,” Battisti said. “You’re talking about hundreds of millions of additional people looking for food because they won’t be able to find it where they find it now.”