The intertropical convergence zone (ITCZ), where the trade winds of the northern and southern hemispheres meet, is the world’s most important rainfall belt. New research suggests that a warming climate could lead to drier conditions in the margins of the zone, potentially exacerbating social tensions and possibly triggering mass migrations in the Neotropics, which include Central America.

Douglas J. Kennett, a professor of environmental anthropology at UC Santa Barbara and one of 10 authors of “Intertropical convergence zone variability in the Neotropics during the Common Era” in the journal Science Advances, said previous research suggested that a warming climate would lead to wetter conditions.