Why Climate Change Might Be Linked To Higher Suicide Rates

While suicide is a complex issue and there's no one factor that causes it, researchers of a new study may have found a link between suicide and something you might not expect: climate change.

The study, published in the journal Nature Climate Change on Monday, suggests that there's a correlation between higher-than-average hot weather patterns and higher rates of suicide. Researchers looked at temperature and suicide data from the U.S. and Mexico over the course of several decades, and found that during hotter months, suicide rates were higher than they were during months when temperatures remained average. More specifically, suicide rates rose when monthly average temperatures increased by one degree Celsius.

What's more, while researchers acknowledged that suicide is a complex issue, they predicted that with the projected temperature increases in the next few decades, there could be an estimated 21,000 more deaths by suicide tied to climate change by the year 2050.

Marshall Burke, PhD, an assistant professor in the Department of Earth System Science at Stanford University and lead author of the study, says that while scientists have long noticed that suicide rates were higher during warmer months, he and his fellow researchers were surprised at how consistent their findings were in the new study.

"Our results differ very little based on how rich populations are or if they are used to warm weather, or if we looked at the U.S. or Mexico," he says.

The idea that hot weather can be associated to negative emotions definitely isn't new. (And the rising rate of suicide unfortunately isn't new either — earlier this year, the CDC found that rising suicide rates have risen by 30% since 1999.) Past studies have suggested that suicide rates spike in the spring and summer, and other studies have also linked hot weather to violence and aggression, something that Dr. Burke notes in his team's research.

"We actually think our results could be related to other findings that have linked hot weather to violence and aggression," Dr. Burke says. "Suicide itself is often a violent act, and like other types of violence, is also impulsive. It could be the case that hot temperatures cause people to act more impulsively, and that this then causes increases in various types of human violence, from aggravated assault to homicide to suicide."

And back in April, Lata McGinn, PhD, a licensed clinical psychologist and member of the Anxiety and Depression Association of America, told Refinery29 that the increased suicide rates could be because someone may have already been going through depression in the winter, and the warm weather has given them more energy that propels them to act on suicidal thoughts.

However, the study Dr. Burke and his colleagues conducted didn't just look at short term spikes in temperature, it examined long term changes in the climate over the course of years. That being said, climate change, of course, isn't the only risk factor for suicide, nor are researchers saying that it's a direct cause for suicide, but Dr. Burke says the researchers have found a significant enough link that it warrants further study (or a closer look).

"Climate change is almost surely not one of the most important causes of high suicide rates," he says. "But what we find is that changes in climate could lead to a lot more suicides in the future, and these changes are large enough to warrant substantial policy attention."

The idea that something as serious and seemingly impending as climate change could be linked to suicide is bleak — after all, there's no easy solution for global warming. Dr. Burke, however, says that it isn't too late to start addressing climate change as a factor in rising rates of suicide.

"We hope that our results also provide another tool for mental health professionals to help determine when and where people might be at particular risk of suicide," he says.