Human beings could disappear sooner than expected. Le Monde report
Over the last seventy years, the fertility rate has more than halved, going from 4.8 children per woman in 1950 to 2.2 in 2021 and, according to a recent study, it could reach around 1.8 in 2050. Alarmism or realism? The Le Monde article
Research published Wednesday in the journal The Lancet predicts a faster-than-expected decline in human fertility worldwide. Produced by the international collaborative project Global Burden of Disease (GBD) and led by the Institute for Health Metrics and Evaluation (IHME), the study concludes that by 2050 the average fertility rate could be around 1.8 children per woman overall the world. This is a value lower than the population renewal threshold, writes Le Monde .
An index which, according to this research, could fall to 1.6 children per woman by the end of the century. By way of comparison, the latest United Nations projections, published in 2022, indicate an average number of children per woman of around 2.1 in 2050 and 1.8 in 2100.
The GBD analyzed the evolution of global demographics between 1950 and 2021 and modeled the evolution of fertility rates, country by country, until the end of the century. Over the last seventy years, the fertility rate has more than halved, from 4.8 children per woman in 1950 to 2.2 in 2021.
THE SCHISM OF THE BIRTH CRISIS
The researchers conducted their analysis country by country and expect a more or less general decline. Not only in Northern countries, which are generally already below the replacement level – in 2021, Western Europe will have around 1.5 children per woman (1.75 in France) – but also in Southern countries, with the urbanization of the population, women's access to education and contraception, the decrease in infant mortality, etc. In 2021, approximately 46% of the 204 countries or regions considered were below the replacement threshold; this percentage could rise to 76% in 2050 and 97% in 2100.
The authors predict a birth schism, with sub-Saharan Africa remaining the world's only dynamic region for much of this century. “As human civilization converges on the reality of low fertility,” the researchers write, “relatively high rates in some low-income countries and territories will lead to a sharp demographic divide between a subset of low-income countries and the rest of the world. world".
Researchers predict that by 2100 only Samoa, Somalia, Tonga, Niger, Chad and Tajikistan will remain above the population renewal threshold. At the other extreme, Bhutan, Nepal, Bangladesh and Saudi Arabia could see their fertility rates fall below one child per woman.
THE IMPLICATIONS
“The implications are dramatic,” said Natalia V. Bhattacharjee of IHME, a co-author of the research. These future trends in fertility rates and live births will completely reconfigure the global economy and the international balance of power and require a reorganization of societies.”
Contrary to the political zeitgeist in France and Europe, she predicts “international competition to attract migrants and support economic growth as the baby boom continues apace in sub-Saharan Africa.”
As for the "demographic rearmament" hoped for by Emmanuel Macron, it is unlikely that it will be able to stop the downward trend: researchers estimate that birth rate policies have only a marginal effect, on the order of an increase of just 0.2 children per woman .
CRITICISM OF THE STUDY
Every time population projections are published, they generate numerous comments. The GBD's previous publication on the topic, in 2020 in the Lancet , attracted a large number of critical comments, not only on the method used, but also on the wording of the results.
Some members of the scientific community and civil society have even criticized the authors for their alarmist tone, which could trigger public policies that could jeopardize women's freedom to control their fertility.
“It is always positive when new estimates are presented, but it is regrettable that the model used is too simple and that it is supposed to work in all countries in a way that is assumed to be stable throughout the century,” says Laurent Toulemon, research director of the French National Institute for Demographic Studies, which has reservations about the reliability of the techniques used by GBD researchers.
For his part, epidemiologist and public health physician Hagaï Levine, of the Hebrew University of Jerusalem, who has worked on male fertility, believes that the GBD projections are “important, based on a well-accepted methodology, and should serve as basis for public policies".
In July 2022, James Pomeroy, an economist and statistician at HSBC bank, contributed to the public debate on the topic by publishing a note that also downgraded the United Nations' estimates of the planet's demographic future. These estimates have sparked heated debate, with many demographers deeming them exaggerated.
AND WHAT ABOUT BIOLOGICAL FERTILITY?
Interviewed by Le Monde , Pomeroy said he agreed with the new GBD estimates. “This type of modeling has some limitations when it comes to clarifying the sharp decline in births we are seeing, because the social and economic challenges for a specific age group play an important role,” he says. “Younger generations appear concerned about climate risks, geopolitical uncertainty and changing priorities regarding whether to start a family.”
Furthermore, he adds, “income inequality between generations makes it much more difficult for young people today to have children.” The British economist concludes that “statistical models are likely to overestimate birth rates in developed economies in the coming years”.
And that's not all. The erosion of human biological fertility is not discussed by the authors, as the Danish doctor Niels Skakkebaek, one of the pioneers of studies on male reproductive health, regrets to Le Monde .
“So far,” says Toulemon, “there is no evidence that the deterioration of human sperm quality, which is a proven and global phenomenon, has had an impact on population-level fertility rates… although this does not mean that it has not will have in the future."
(Excerpt from the foreign press review edited by eprcomunicazione )
This is a machine translation from Italian language of a post published on Start Magazine at the URL https://www.startmag.it/sanita/lessere-umano-potrebbe-scomparire-prima-del-previsto/ on Sat, 23 Mar 2024 06:16:53 +0000.