A recent study links temperatures above or below the comfort zone of 12–21 degrees Celsius (54–70 °F) to an increase in online aggression in the United States. Researchers from the Potsdam Institute for Climate Impact Research analysed billions of tweets posted on the social media platform Twitter in the United States and discovered an increase in hate speech across climate zones, income groups, and belief systems in response to excessively hot or cold temperatures. This demonstrates the limits of adaptation to severe temperatures and throws light on an underappreciated societal impact of climate change: conflict in the digital realm, which has repercussions for both social cohesion and mental health.
To reach these conclusions, the authors utilised a machine-learning technique to detect nearly 75 million English-language tweets containing hate speech from a dataset of more than 4 billion tweets posted on Twitter in the United States between 2014 and 2020. The authors next investigated how the amount of hateful tweets changed when local temperatures rose or fell. In defining hate speech, the researchers were guided by the official UN definition: cases of discriminatory language directed at a person or group based on their religion, ethnicity, nationality, race, colour, descent, gender, or other identity factor.
The authors discovered low levels of hate tweets in a “feel-good window” of 12–21°C (54–70 °F) across the United States, with the lowest levels occurring between 15 and 18°C (59–65 °F). Increasing heat and cold are associated with an increase in hateful tweets. Depending on what temperatures are typical in a given climate zone, the specific range of comfortable temperatures varies slightly. Temperatures exceeding 30°C (86 degrees Fahrenheit) are, however, consistently associated with significant increases in online hatred across all climate zones and socioeconomic inequalities, including income, religious views, and political inclinations.
This demonstrates the limits of temperature adaptation: “On exceptionally hot days, we detect an increase in hate speech even in high-income neighbourhoods where people may afford air conditioning and other methods of heat mitigation. In other words, there is a restriction on what individuals can take. Thus, it is probable that there are adaption limitations to extreme temperatures that are lower than our physiological limits “According to Anders Levermann, director of Complexity Science at the Potsdam Institute, Columbia University researcher, and co-author of the study.
Hate speech has been observed to negatively affect the mental health of online hate’s victims, indicating that more aggressive online behaviour can have severe implications. Additionally, it can anticipate hate crimes in the real world. “For decades, scientists have pondered how climate circumstances affect human behaviour and societal stability,” adds Leonie Wenz, chairwoman of the working group at the Potsdam Institute that conducted the study.
Temperature impacts on hate speech online: evidence from 4 billion geolocated tweets from the USA, The Lancet Planetary Health (2022). DOI: 10.1016/PIIS2542-5196(22)00173-5