Heat spells and downpours are serious mood killers, a huge analysis of Twitter conversations confirms. The international study is part of efforts to understand how climate change affects mental health around the world. Scrutinizing tweets from 190 countries, nearly every one on Earth, researchers looked at how “positive” and “negative” expressions shifted during extreme heat and rainfall events. Unsurprisingly, they found that during bad weather, negative sentiments became noisier and positive expressions became few and far between in each region. While it might seem obvious that bad weather can put people in bad moods, researchers see the consistency of the findings as a warning that people might be struggling to adapt to climate change. “We see very little evidence of adaptation” “As of right now, we see very little evidence of adaptation in the way that these new extreme events that are emerging globally are impacting human sentiment,” says Kelton Minor, a postdoctoral research scientist at Columbia University who presented the study at the American Geophysical Union Fall Meeting this week. There’s been research on …