Scientists have confirmed that extreme heat influences how people feel and behave. By analysing over a billion social media posts, they observed emotional patterns tied directly to rising temperatures. Once the heat crossed 35°C, negativity increased, with stronger effects in poorer regions than in wealthier ones.
The research team, including MIT experts, assigned sentiment scores to online posts from 157 countries. They compared each score with local temperature data. Findings showed that low-income countries experienced far greater mood declines than high-income societies, illustrating unequal burdens of climate change.
Behaviour in Hot Conditions
Research over decades links heat to irritability and aggression. Traffic studies revealed more honking during hot weather. Reports written in heatwaves often had harsher tones. Crime records and historic accounts connect violence and uprisings to hotter periods. In Greece, a large share of murders took place on unusually warm days, while other studies associate hot weather with increased suicide.
Scientists suggest possible explanations, from changes in serotonin levels to hormone spikes that heighten aggression. However, environmental and social pressures may also intensify these reactions.
Preparing for What’s Ahead
Climate projections suggest global optimism could drop by more than 2% by 2100 due to rising heat. Groups underrepresented online, such as young children and older adults, might feel the impacts even more severely.
Experts warn that adaptation must include emotional resilience. Addressing both the psychological and physical consequences of heat will be essential in a warming world.
