Scientists are striving to figure out the side effects of global climate change before they hit us like a ton of bricks. You’re likely familiar with some of them including more drastic weather phenomenons, rising tides, and animal dead-offs. But an increase in girl babies? That’s a new one.
New research has shown that global climate change could mean more girl births. Researchers in Japan observed birth ratios and aligned them with temperatures from 1968 to 2012 and found that boy births are declining compared to girl births because it appears that boy fetuses are more vulnerable to fluctuating weather. This means that male fetuses saw an increase in miscarriages as a result of the hot summer in 2010 and the cold winter in 2011, while female fetuses saw no change.
“Male conception seems to be especially vulnerable to external stress factors, including climate changes,” reported the study on TreeHugger.
There’s evidence that the sex ratio is sensitive to other factors as well like pollution in Scotland which seemed to increase girl births again. Additionally, tropical countries tend to produce more girls. But the science is far from clear on the subject.
“The main thing to remember is that [the study in Japan] shows a correlation, which is not the same as causation,” said Timothy Mitchell, from Iowa State University, who studies how temperature affects sex determination in reptiles.
Reptiles are even more sensitive to global climate change than humans. For example, Loggerhead sea turtles lay more female eggs during the warmer months. However, global sex ratios are still higher for boys: 101 boys to 100 girls. Though we’re not completely sure why, some countries including China and India still selectively abort girl babies.
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Image: Anthony J