In a working paper released this week, economists with the National Bureau of Economic Research concluded that climate change is linked to reduced “coital frequency,” in an analysis of U.S. birth rates between 1931 and 2010. But according to some environmentalists, a lower birth rate might not be a bad thing for the planet.

The global population sits at around 7.2 billion people. By 2050, that number will rocket to 9 billion, a load that many have claimed the earth cannot support without massive innovation. In 1968, Paul R. Ehrlich published The Population Bomb, which argued that overpopulation could lead to mass starvation. As increasingly extreme weather threatens food supplies, that scenario may come closer to reality.

A paucity of resources and the damage we are inflicting on the planet has greens all over asking whether reproduction is as much an environmental sin as failing to recycle plastic bottles. At Grist, Katie Herzog writes, “Reproducing when climate apocalypse looms seems selfish, misguided, and even worse, cruel.”

The NBER's paper, “Maybe Next Month? Temperature Shocks, Climate Change, and Dynamic Adjustments in Birth Rates,” explains that as birth rates decline, they will not immediately bounce back due to extremely high temperatures, which are only expected to increase as climate change worsens. Accordingly, the U.S. could experience a 2.6 percent decline in its birth rate. That may seem small, but according to Bloomberg Business, which first reported the paper, that could result in 107,000 fewer births every year.

“The lack of full rebound suggests that increased temperatures due to climate change may reduce population growth rates in the coming century,” the paper says. “As an added cost, climate change will shift even more births to the summer months when third trimester exposure to dangerously high temperatures increases.”

Reduced birth rate is just the latest in a laundry list of consequences stemming from climate change. Nonetheless, according to the paper, there may be a way to make sure fertility doesn’t fall into a downward spiral: air-conditioning. If only all climate change solutions were so simple.