The world may have more women because of climate change

Sudden climate change can result in a change in the proportion of men and women in the world: temperature variation is the cause of fewer male babies being born.

The finding comes from a Japanese study headed by Dr. Misao Fukuda of the M&K Institute. Research shows that temperature fluctuations in Japan, accentuated in the 1970s, were the main factor behind an increase in the number of women being born in the country.

A more feminine Japan

The study analyzed data from 1968 to 2012, provided by the Japan Meteorological Agency, as well as data on the death of fetuses and children born in the same period, figures taken from the Japan Vital Statistics Bank.

A more recent event analysis, based on a warmer than usual summer in 2010 and a harsh winter in 2011, was conducted in conjunction with the survey. During the period of high temperatures, there was an increase in dying fetuses and, nine months later, a decrease in the number of male babies being born. The trend continued in January 2011, with a sharp drop in temperatures.

The findings suggest that climate fluctuations in Japan are directly related to the sex ratio of newborns, but climate vulnerability in male fetuses was not justified in the research.

In China too

Other research reinforces the idea that you are more likely to hear “It's a girl!” During times of crisis - with no binding relationship to climate change.

An analysis by Shige Song, a sociologist and demographer at Queens College in New York, found the famine during The Great Leap Forward in China.

The campaign launched by Mao Zedong aimed to make China a communist nation in record time, but the result was disastrous: about 30 million deaths, droughts, floods, lack of transportation and famine shook the leader's plans.

As in the Japanese study linking climate change to a shrinking male population, Song found a drastic drop in the birth of boys during The Great Leap Forward campaign.

Women are sure bet

Still according to Song, the theory of female predominance during hard times makes sense in the evolutionary aspect: “In good condition, invest in children; under difficult conditions, invest in daughters. ”

The sociologist exemplifies: A male lion can have many children, so a male offspring birth represents a good chance of passing on the genes. However, lions with non-dominant behavior may not be able to successfully mate at least once.

The female reproduction level, in this respect, is slow and constant. Although capable of raising their children regardless of the situation, they do not have the fecundity of the males, which implies a clear but less lucrative bet when passing the genes forward.