We investigate the impact of climate shocks on farmer-herder violence, using geolocalized data on conflict events for Africa, 1997-2014. We find that a one degree temperature increase yields a 54% increase in conflict probability in mixed areas populated by both farmers and herders (versus 17% in non-mixed areas). Quantifying the impact of projected climate change in 2040, we find that -when factoring in the magnifying effect of mixed settlements- annual conflicts are predicted to rise by a third. Drawing on a fine-grained analysis of groups' mobility patterns, we show that resource competition is a major driver of farmer-herder violence.