A hotter Earth has fewer babies on it.
Image via Flickr user Jim.henderson
Climate change is totally killing the mood, according to working paper released last month by researchers at the National Bureau of Economic Research. In the hilariously named study, “Maybe Next Month? Temperature Shocks, Climate Change, and Dynamic Adjustments in Birth Rates,” economists Alan Barreca, Olivier Deschenes and Melanie Guldi use nearly 80 years of climate and fertility data to determine whether temperature shocks have affected birth rates in the United States.
They find there’s an association between additional very hot days and decreases in the birth rate in the subsequent nine months. As the planet gets hotter, the economists suggest, people are less and less interested in getting busy—and making babies.
More specifically, the researchers find that one additional day above 95 degrees Fahrenheit reduces the birth rate nine months later by 0.7 percent. Ten months later, however, the birth rate increases by 0.4 percent. (This would appear to be parents-to-be “making up for lost time.’) But overall, these extra hot days still lead to a small decrease in the birth rate.
In the short term, this decrease isn’t a huge deal. But if climate change continues on trend, the researchers say, there will be a 3 percent decline in American births between 2070 and 2099—and a 5 percent decline in the hotter southern U.S. That’s over 100,000 fewer babies born each year.
“This projection indicates climate change will exacerbate the already ‘below-replacement’ birth rates in the United States, which is a concern for public finance and economic growth,” the economists write.