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Could climate change influence human fertility?

Climate change is an issue that has been very much on the international public agenda for a couple of decades. People often talk about the natural disasters that this phenomenon would cause, such as long droughts in some areas of the planet or the melting of the poles. This information, although it causes great impact, is not the only one that worries scientists.

The effects of excessive consumption and climate change on human health and that of other living beings is not a matter that is often discussed, but there are already serious studies that reveal a clear incidence of high temperatures on animal and human fertility. The possible risks of this lie in the imbalance of life that would be generated by significantly affecting the birth rate.

What is the relationship between declining birth rate and climate change?

A priori, it does not seem an obvious relationship, but based on research on the subject, there are several interesting points that I am interested in highlighting and that are no less worrying than the catastrophic consequences on the planet. Below, I will list some results that although they are not yet the focus of concern, it is necessary to raise awareness about them.

Climate change has an impact on male fertility

A study by the University of East Anglia (England), led by Professor Matt Gage, revealed that heat waves could be affecting male fertility, which would explain the population decline in certain species and even their extinction in some cases.

For this research, the behavior of male red flour beetles in the face of heat waves was observed. A potential effect on sperm production and offspring quality was demonstrated. A first heat shock decreased the amount of offspring the male could produce and a second heat shock rendered them virtually sterile.

Sperm production decreased by approximately three-quarters and the sperm that were produced had mobility problems and difficulties in reaching the female reproductive tract, increasing the chances of dying before fertilization.

Other important results were: mating frequency was reduced by half, the offspring lived less and their reproductive behavior was also negatively affected. These findings are highly relevant to how other species on the planet would react to climate change. We know the vital importance of insects and all animal species in the ecological balance and life on the planet.

Climate change and toxic lifestyles affect human fertility

But insects are not the only animal species that would suffer the consequences. The low nutritional quality of food, air and water pollution, as well as a stressful lifestyle are direct risk factors that significantly affect human fertility. This, among other things, has increased the demand for fertility treatments and in vitro fertilization in a worrying way.

In reference to climate change, the relationship is indirect, but no less worthy of note. Heat causes agricultural crops to fail in poor regions, contributing to increased poverty and the need to migrate labor to other areas. This influences family planning, increasing the birth rate.

A very different situation occurs in developed countries, where uncertainty about the future makes for a discouraging outlook for the new generations. This makes couples decide to have few children to guarantee them a good education and quality of life or, definitely, not to have any at all and save them from surviving in an increasingly unwelcoming world.

The researcher and doctor Jan Tesarik affirms that environmental problems lower the quality of eggs and sperm in developed countries and that, together with the fact that women decide to carry out their maternity project at a late age, puts the birth rate in the West at great risk.

According to La Vanguardia: "The infertility rate reaches 17% of the population and will continue to grow (...) The infertility rate in Spain is between 15 and 17% of the population, with some 800,000 couples who have fertility problems, and the trend is increasing, according to the organizers of the 5th International Congress on Reproductive Medicine organized by the IVI group. (...) According to data from the Spanish Infertility Society cited by the IVI group, 50,000 in vitro fertilization treatments and almost 30,000 artificial insemination treatments are performed in the country every year."

Can demographic decline contribute to the reduction of CO2 emissions?

Contrary to popular belief, it is consumption habits and not population density that worsen climate change. However, researchers are also unclear about the consequences of an imminent drop in the birth rate in the coming decades.

According to a study published in "The Lancet", by the end of this century the world's population will decline in almost all countries of the world. In about 80 years the populations of Spain and Japan will be halved, leaving India and Nigeria as the nations with the most people. Only 12 countries, including South Sudan and Somalia, would have enough population to create a balance in their economies.

For some powers-that-be, the idea that overpopulation is solely responsible for excessive CO2 emissions into the atmosphere is very convenient, since we would only have to focus on population decrease and not on behavioral change.

But the truth is that some scientific studies have shown that not all populations emit the same amount. Paradoxically, poor countries with high population density emit less than developed and rich countries, where it is up to 50 times higher. For Zeke Hausfather, a climate scientist at the Breakthrough Institute in California, excessive consumption patterns and the type of economic activity is what really generates the excess CO2 emitted.

This would lead to the conclusion that an overpopulated world, but with the use of clean energy could be much better for the planet than one with less population and using highly polluting fossil fuels.

What do you think about this interesting data, do you think that the decrease in the world's human population will be positive or negative, and will the effect on the animal population allow us to be in a viable world?

In the meantime, we must continue providing education for a cleaner world, with people who practice healthier habits, from an ecological point of view. It seems to me that this should be the bet.

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