Global Warming Will Cause More People to Commit Suicide, Study Says
STANFORD, CALIFORNIA — July 24, 2018
New research from Stanford University finds that higher temperatures are leading to more suicides.
In the study, published in Nature Climate Change, investigators looked at decades of county-level suicide data — nearly 1.5 million observations spanning all of the United States and Mexico — as well as data that tracked monthly temperatures in each area.
Then they observed temperature fluctuations over these periods in every county or municipality in both countries correlated to the suicide rates for that region.
It was discovered that for every 1-degree Celsius rise in temperature, there was a 0.7 percent increase in suicide rates in the U.S. and a 2.1 percent increase in Mexico, averaging a 1.4 percent increment across both countries.
"A lot of times when you hear about climate change and climate change impacts, you hear this catchphrase ‘climate change is going to generate winners and losers," says study author Marshall Burke. "Some people could benefit from climate change, the idea being if you live in a really cold location, sometimes things improve when you warm it up a little bit. We do not find that for suicide."
If climate change continues on its current trajectory with an estimated temperature increase of 2.5 degrees Celsius by 2050, scientists projects suicide rates will rise by 1.85 percent; as a result, the rate would increase to 21,770 deaths by suicide across the U.S. and Mexico.
The economic recession is thought to increase suicide rates by 0.8 percent whereas news of celebrity suicides accounts for a 4.6 percent bump in rates.
According to Jill Harkavy-Friedman, vice president of research at the American Foundation for Suicide Prevention, such forecasts are not always accurate.
"I think it’s an interesting and provocative idea. These two things may be co-occurring. You know, it’s possible that the rate of suicide is going up as the temperature is going up. But we don’t know that there’s anything casual about that."
In the new study, the researchers speculate that the increased rates could be linked to temperature regulation in the brain and other biological effects. They also found hotter months corresponded to a higher probability of using depressive language.
Since "everyone is going to experience temperature increases," Burke says, "the toll from mental health could be incredibly large."
In the future, Burke hopes to expand the geographical scope of his research to "build a global picture" of climate change and its worldwide mental health effects.
However, the temperature is certainly not the only or even the most important factor affecting mental health, the researchers noted.
Burke says there is "emerging physiological evidence" that the parts of the brain involved with regulating emotion are also used when dealing with heat. While "there is a plausible link here," he says, the mechanism linking heat to suicide remains an open question.