New research suggests that even a moderate amount of warming could force populations in the tropics to undergo huge migrations — longer journeys than they’d have to take if they lived anywhere else on the planet — to get to cooler ground. “The point we’re trying to make in the paper is people are not really talking about the tropics,” said Solomon Hsiang, the chancellor’s associate professor of public policy at the University of California Berkeley and the new study’s lead author. “The tropics, because of very specific patterns that occur [there], are a place where we might actually be really concerned.” Hsiang co-directs the Lab.