It is a study decried by demographers. According to work by an HSBC economist, James Pomeroy, unveiled on August 22, the world’s population could be halved by 2100, from around 8 billion to 4 billion at the end of the century due to a fall in the birth rate, rising mortality and the integration of women into the labor market with a later first birth. “The likelihood that the size of the world’s population will start to shrink in the next 20 years is much higher than we originally predicted,” he said.
The alert is given in Europe, according to James Pomeroy, where “the population will have halved before 2070” if the current rate is followed. With more than 67 million inhabitants today, France could end up with 62.3 million according to these forecasts.
Yet, according to a medium projection by the UN Department of Economic and Social Affairs published on July 11, 2022, the world population – which is expected to reach 8 billion people on November 15 – could reach around 8.5 billion in 2030 and 9 .7 billion in 2050, peaking at around 10.4 billion people in the 2080s before remaining at this level until 2100.
But for James Pomeroy, the United Nations projections are irrelevant. For the economist, the peak could be reached well before, around 2043. To support his hypothesis, he relies in particular on the fertility rate of the population. This rate is falling, which the UN had also confirmed by citing a rate of 2.1 in 2050, against 2.3 in 2021.
“The future is not written”
“James Pomeroy’s study is not at all founded. He is not a specialist in these questions and we can regret a lack of knowledge of the current literature on this subject”, reacts to L’Express the demographer Hervé Le Arms. “I don’t see how you can get to that figure of 4 billion people at the end of the century. I think he took curves and extended them.”
Questioned by L’Express, Gérard-François Dumont, demographer and geographer, also calls for caution. “It has no value insofar as it would have been necessary to make a set of hypotheses, we must not be limited to a single hypothesis”, estimates this professor at the Sorbonne, in Paris, specifying moreover that “the The future is unwritten and anything can happen, one way or the other”, as we have seen with the Covid-19 pandemic.
According to him, it is only possible to arrive at the figure of 4 billion human beings in 2100 by “adding a certain number of negative factors” such as “the deterioration of the sanitary systems”, “hygienic behavior which would be more and more bad” or the rise of pollution in the world. All these “remote determinants” have consequences on the fertility and mortality rate, underlines the author of Geography of populations: concepts, dynamics, prospects (Armand Colin edition). But, for all that, they cannot lead to the reduction of half of the world’s population in 80 years.
For Canadians John Ibbitson, a great journalist at the Globe and Mailand Darrell Bricker, CEO of Ipsos Public Affairs, authors of empty planet (the Arenas), the population “should rather reach a maximum of 8 to 9 billion humans in the middle of this century, before experiencing a significant decline” again due to the drop in births. According to the UN, the world’s population is currently growing at its slowest rate since 1950, while median fertility has fallen from 5.4 children per woman in 1950 to 2.3 children per woman in 2021. According to John Ibbitson and Darrell Bricker, this dramatic decline in fertility rates around the world is linked to the planet’s urbanization “at a spectacular rate”. “In the countryside, the child represents an economic asset, with extra arms to work in the fields. But when you move to town, it turns into a financial burden”, explained in 2021 John Ibbitson in an interview with The Express.
“The world population explosion is over”
“Today, this idea of a planet that will be emptied of its population is becoming more and more necessary”, also estimated Darrell Bricker with L’Express. “Everyone today agrees that the world’s population will shrink drastically. The only debate among demographers is ‘when?’ and ‘how fast?’, he added. ‘The only thing we are sure, it is that the explosion of the world population is over, but we do not know to what extent this will go down more or less quickly”, estimates for his part Hervé Le Bras. The demographer regrets that this worrying figure of 4 billion human beings in 2100 given by James Pomeroy “overshadows this extremely important change” represented by the passage “from an increasing world population to a decreasing population, a point on which there is no disagreement”.
“It is true that the world population is decelerating”, also relates Gérard-François Dumont, but the world growth rate “has been decreasing year after year since the end of the 1960s”. This slowdown will “inevitably lead to stagnation one day, we are already seeing it in countries like China”, estimates the president of the magazine. Population and future. He recalls that Africa has already entered into a demographic transition with a drop, on average, in infant mortality rates as well as a drop in fertility, even if the figures vary according to the country. “When infant mortality drops, people end up adapting to lower fertility,” he notes.
More generally, Gérard-François Dumont believes that “the notion of world population has no meaning” insofar as “the demographic reality is local”. He cites as examples Mexico and Japan, two countries which have a comparable population but which “have totally different demographic trajectories”.