In an effort to evaluate whether high temperatures were implicated in mental well-being, the researchers analyzed data from more than 600 million geotagged Twitter posts, and found that each additional 1 ˚C in monthly average temperatures increases the likelihood of “depressive” language in tweets—like “lonely,” “trapped,” or “suicidal”—by as much as 1.35 percent.

The paper joins a growing body of research finding that climate change will have wide-ranging impacts on human health and well-being. Earlier work by two of the authors, Marshall Burke at Stanford and Solomon Hsiang at Berkeley, concluded that it will also significantly increase violence around the world (see “Hot and violent”).

“Now we see that in addition to hurting others, some individuals hurt themselves,” Hsiang said in a statement. “It appears that heat profoundly affects the human mind and how we decide to inflict harm.”