This is approximately the same change in suicide rates triggered by "the estimated impact of economic recessions, suicide prevention programs, or arms control laws."
It also concludes that people can do little about this suicide-climate link beyond developing better medical care to specifically target suicide. The normal adaptation of people to high temperatures – such as the installation of air conditioning – does not seem to affect the suicide rate.
Suicide is the second leading cause of death among Americans between 10 and 34 years old. It is also one of the few major causes of death in the United States where the age-adjusted mortality rate does not decline. In other words, more people die by suicide than they used to.
"I found the results convincing and the methodology strong," says Gregory Tasian, professor of epidemiology and biostatistics at the University of Pennsylvania, who does not agree with the
"It blends very well into the overall census of the impact of Climate change and high temperatures on human health and includes another aspect of human health that is often neglected, namely mental health, "he told me.
The new paper provides unusually robust evidence that high temperatures will only exacerbate it.
First, the new paper has a causal claim: Unusually high temperatures actually seem to be cause suicide rates are rising. The authors have checked for every other important variable that might influence suicide rates. The effect does not seem to change if the victims are men or women when the month is January or June, when they live in an American city or in the Mexican countryside. Even in areas where weapons are abundant, it does not fluctuate.
Second, the effect shows up everywhere : in Fargo and Houston, in Ohio and Oaxaca. "We see the same effect size in hot places compared to cold places," said Burke.
Previous studies on climate change and mortality have revealed that the effects of global warming on mortality are mixed. For example, in a groundbreaking study last year, a team of economists found that warmer temperatures bring modest economic benefits to the upper Midwest and New England as they mitigate the deadly winters of those regions. (The Sunbelt, however, will suffer much worse costs in the summer.)
Not so for the suicide rate, which will rise everywhere under global warming.
"Climate change will produce winners and losers" This is a phrase that is heard all the time, "said Burke," but for this result it is all losers. There are no winners. We find these strong linear relationships everywhere as you increase the temperature. "
Finally, the paper finds that there are few ways to blunt this effect: In previous studies, economists have found that the adoption of air conditioning tends to reduce the heat-related mortality over time, but the climate suicide Compound does not show the same flexibility.