Climate change has a multitude of effects on the environment and humanity. From sea level rise to economic fall down, the environmental issue seems to have a link to everything. Now, a new result from global warming has been raised: lesser sex frequency leading to decreased birth rates.

In a working paper by the National Bureau of Economic Research, the authors suggest that high temperatures may result in people not wanting to have sexual intercourse frequently.

In the report, the researchers found that birth rates significantly plummeted approximately nine months after a particularly hot day. More specifically, the birth rate decreased by as much as 0.7 percent compared to when it followed a cooler day.

The findings signify that hotter temperatures may result in two things: reduced fertility or decreased inclination to have sex. The researchers said both scenarios may be possible. Reduced fertility or impaired reproductive health for men may mean poor semen quality; in women, it may mean that ovulation becomes affected. As for the decreased appetite for sex, this may signify fluctuations in hormone levels and impaired sex drives.

The researchers also found that days with temperatures exceeding 80 degrees Fahrenheit result in significant drops in birth rates about eight to 10 months later.

The birth rates, however, were observed to partially rise or "rebound" after a couple of months. This observation may mean that people adjust to the effects of high temperatures by changing the month of conception.

The authors wrote that the adjustment may aid to explain the drop in birth rates in the spring season and rise during the subsequent summer. Another possibility being anticipated is that global warming will move even more births to the summer months, when there is an increased risk of exposure to hazardous high temperatures.

Although it occurs a few months after the decrease in birth rates, the rise in birth rates is not sufficient as it only compensates for 32 percent of the drop. With the absence of a complete rebound, the findings suggest that high temperatures due to climate change may decrease populations over the next century.

The researchers then recommend the use of air-conditioning units to significantly make up for the effects of climate change on fertility. 

One of the authors, Alan Barreca from Tulane University, said that even though the study focuses on the population of the United States, the issue may affect developing countries even more significantly.

"The decline in birth rates is a very serious issue for countries, like the United States and the UK, which have below-replacement birth rates," he said. Decreased birth rates due to climate change will also pose massive stress on social programs as it will cause the population makeup to become heavily imbalanced. 

Photo: Katie Tegtmeyer | Flickr