A recent study conducted by researchers at UC Berkeley and Stanford University found that suicide rates might rise because of climate change.

Published July 23 in the Nature Climate Change journal, the study examined suicide rates and social media posts during hotter periods and concluded that an additional 21,000 suicides might occur in the United States and Mexico by 2050 as a result of temperature increases over the next few decades.

“This may be the first decisive evidence that climate change will have a substantial effect on mental health in the United States and Mexico, with tragic human costs,” said Solomon Hsiang, a campus associate professor of public policy and the study’s co-author, in a press release.

The study projected a 1.4 percent increase in suicide rate in the United States and a 2.3 percent increase in suicide rate in Mexico.

In addition to suicide rates, the researchers examined Twitter posts during these hot spells and found that more people posted “depressive content” on Twitter during the hotter periods, according to Patrick Baylis, an assistant professor at the Vancouver School of Economics and another researcher involved with the study.

The researchers acknowledged that increasing temperatures are likely not the motivation for suicide but said the temperatures can influence how people make decisions, since high temperatures are a stressor, and violent crime increases during heat spells, according to a 2017 study from Drexel University.

“It showed the correlation, not causation,” said Daniel Kammen, a UC Berkeley professor of energy. “However, a very (small) study more than 20 years ago in the very hot summer of 1988 … saw not only more suicides, but more domestic violence.”

Baylis emphasized that the team is not a group of mental health professionals and that suicide is a complicated issue influenced by many factors.

Baylis also acknowledged that the model used to predict the suicide increase assumed that economic and social norms would be relatively unchanged for roughly the next few decades.

“Things don’t stay equal as they go forward. Things are going to change, and that will have an impact on a variety of social outcomes,” Baylis said. “We don’t have the ability to predict all of these changes.”

The study did not have any recommendations for decreasing the number of suicides other than mitigating the effects of climate change, according to Baylis.

The impact of high temperatures barely changes based on how wealthy populations are, or even based on whether the residents are used to living in warm weather, according to lead author Marshall Burke in a press release. He added that “the effects in Texas are some of the highest in the country.”

“When talking about climate change, it’s often easy to think in abstractions,” Burke said in the press release. “But the thousands of additional suicides that are likely to occur as a result of unmitigated climate change are not just a number, they represent tragic losses for families across the country.”