A new international study shows that extreme heat undermines emotional well‑being. Scientists processed more than one billion social media posts. They discovered negative emotions surged whenever temperatures passed 35°C. The shift was strongest in poorer regions, where heat hit harder.
MIT researchers, with global partners, scored posts from X and Weibo and linked them to local weather. In wealthier countries, negativity rose modestly, but in low‑income areas it increased more than threefold. The findings highlight climate change’s uneven impact on human feelings.
Behavioural Shifts in the Heat
Earlier research supports these results. Drivers honk more during heatwaves, and journalists write more harshly in hot periods. Crime levels rise as temperatures climb, while uprisings and conflicts historically peak in summer months. Data from Greece showed many murders happened on especially warm days. Studies also connect hotter weather to higher suicide risk.
Scientists point to possible causes: changes in brain chemicals like serotonin or hormone shifts that heighten aggression. But they stress that social and economic pressures also interact with heat to amplify mood changes.
Facing the Future
Climate models predict that global positivity could decline about 2.3% by 2100 due to rising heat. Vulnerable groups not well represented on social media, including children and older adults, may feel even greater impact.
Researchers stress that climate adaptation must consider mental health alongside physical protection. Preparing for the emotional effects of a hotter planet is becoming increasingly urgent.
