Global warming is fueling rise in online hate speech, study finds

POTSDAM, Germany — Climate change could be the cause of rising tensions and hate speech online, according to new research. The authors of the Potsdam Institute for Climate Impact Research study say that incidents increase by more than a fifth when the temperature rises.

Global warming puts people warm under the collar during conversations on social networks in particular. Temperatures above 86°F show a consistent link to this phenomenon. The study authors say this applies to all climate zones, regardless of socio-economic differences such as income, religious beliefs or political preferences.

The findings, published in The Planetary Health of the Lancet, have implications for social cohesion, suggesting that there will be more aggression and violence unless greenhouse gas emissions drop dramatically. Scientists used a computer neural network to analyze four billion tweets from users in the United States.

“People tend to behave more aggressively online when it’s too cold or too hot outside,” says study first author and PIK scientist Annika Stechemesser in a Press release.

“Being the target of hate speech online is a serious threat to people’s mental health. The psychological literature tells us that online hate can worsen mental health problems, especially among young people and marginalized groups,” adds Stechemesser. “We find that outside of the 12-21°C (54-70°F) feel-good window, online hate increases by up to 12% for colder temperatures and up to 22% for warmer temperatures in the United States.”

What temperature keeps tempers cool?

The artificial intelligence algorithm identified around 75 million English-language hate tweets in the dataset from 2014 to 2020. The researchers then analyzed how the number changed as local temperatures rose or fell.

Using official UN guidelines, the team defined hate speech as discriminatory language referring to a person or group on the basis of their religion, ethnicity, nationality, race, colour, origin, sex or other identity factors.

“By detecting hateful tweets in over four billion tweets from US users with our AI algorithm and combining them with weather data, we found that the absolute number and share of hateful tweets increases outside of climate comfort zone”, continues Stechemesser.

Lower levels of hate speech appeared online in the “wellness window” of 54-70°F – the least occurring between 59-65°F outdoors. The results indicate “the limits of adaptive capacity to temperature”, according to the team.

“Even in high-income areas where people can afford air conditioning and other heat-mitigating options, we are seeing an increase in hate speech on extremely hot days. In other words: There is a limit to what people can take. Thus, there are probably limits of adaptation to extreme temperatures and these are lower than those set by our simple physiological limits,” says Anders Levermann, head of complexity science at the Potsdam Institute and researcher at the ‘Columbia University.

The consequences can be severe and even lead to more hate crimes in the real world.

“For centuries, researchers have grappled with the question of how climatic conditions affect human behavior and societal stability,” says Leonie Wenz, lead of the study.

“Now, with ongoing climate change, this is more important than ever. Our findings highlight online hate speech as a new channel of impact through which climate change can affect overall societal cohesion and health. This means that cutting emissions very quickly and drastically will not only benefit the outside world, but protecting our climate from excessive global warming is also essential for our mental health.

South West News Service writer Mark Waghorn contributed to this report.

Teresa H. Sadler