New research finds that upticks in the temperature encourages conflict, ” from interpersonal spats — such as aggressive horn-honking by automobile drivers — to full-blown civil war and societal collapse”:

The researchers found that a temperature rise of one standard deviation — which, in the United States today, occurs when the average temperature for a given month is about 3° Celsius higher than usual — increases the frequency of interpersonal violence by 4%, and the risk of intergroup conflict, such as civil war or rioting, by 14%. “The level of consistency in how people are responding was surprising to us,” says Solomon Hsiang, an econometrician at the University of California Berkeley, who led the study. He and his team warn that climate’s influence on behavior is likely to become more apparent as the planet warms and precipitation patterns change.

Tim McDonnell provides examples: