MOSCOW, March 29, Tatyana Pichugina. By mid-century, most countries will complete the so-called demographic transition. And then a process will begin that can lead to big problems. Read about what scientists predict in the material.
Entered the second stage
For simple population reproduction, one woman on average must give birth to at least 2.1 children throughout her life. The indicator, of course, is calculated – it is called the total fertility rate (TFR). At the beginning of the last century it was almost five, and then went down sharply.
In some developed countries, the TFR is critically low, meaning the population is not being replenished. Thus, according to Rosstat data, in 2023 in Russia the total fertility rate is 1.41. This is a multi-year minimum. According to experts, the reason is the small number of women of childbearing age.
It would seem that the situation could not be worse, but experts are in no hurry to draw conclusions. The fact is that since 1950, this figure has more than halved worldwide. The question is why.
Scientists believe that the decline in fertility reflects the so-called demographic transition. This concept appeared in the middle of the last century and is receiving more and more evidence these days. Countries are assumed to have three stages of development. At first, the birth rate and death rate are high, and the population remains low. Then, due to advances in medicine, mortality decreases, living conditions improve, life expectancy increases, and the population increases sharply. At the same time, the birth rate is falling.
At the third stage, the birth rate and death rate are low, in balance, and there are a stable number of people. According to calculations, countries with TFR below 5.5 are in the second stage. Today it is the whole world.
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When collapse happens
In 1972, members of the Club of Rome presented the report “The Limits to Growth,” which described scenarios for the development of mankind. Five of them led first to a peak of overpopulation by the middle of the 21st century at the level of 10-12 billion people, and then to a sharp drop in living standards. The forecast caused a lot of noise, it was actively discussed in the world and criticized. However, facts are stubborn things.
Once every ten years, the scenarios of the World3 model used in the report are revised and compared with observations. Thus, in 2014, Australian researcher Graham Turner calculated that the world is moving according to the Business as usual scenario (as if nothing had happened), according to which around 2020 the growth in living standards will slow down due to the depletion of natural resources, and with By 2030 the collapse will begin. If it turns out that there are still twice as many resources as is believed, then the Business as usual – 2 (BAU2) scenario will be activated.
None of the 12 proposed options, even with collapse, leads to the complete disappearance of people, but the prospects are bleak. It would be preferable to go for the Comprehensive technology (CT) or Stabilized world (SW) scenarios. The first includes many technological solutions that help deal with the world's problems, including pollution. For a “Stable World”, in addition to technology, social issues need to be highlighted. Among other things – control over family size, deliberate limitation of industrial production, focus on education and health care. This is the only way to avoid collapse, writes Dutch econometrician Guy Harrington.
“The observations are now more consistent with the CT and BAU2 scenarios, which lead to lower living standards in the next decades, but whether there will be a collapse is an open question,” concludes Harrington.< br />
Recently, scientists from Germany revised the model and concluded that there is no big difference between BAU and BAU2 and a collapse is inevitable a few years after the population peak. According to calculations, this will happen between 2024 and 2030 due to the depletion of resources, which will be reached earlier than critical pollution.
A world on the verge of change
In each scenario, the planet's population peaks and then declines. There are now 7.8 billion people on earth. The UN predicts 10.4 billion by the end of the century. According to the demographic transition model, stagnation should begin around this level.
Recently, The Lancet published a report from the International Fertility and Forecasting Program. Calculations have shown that for 2021 the TFR of the planet is 2.23. For 94 countries this figure is still above critical. Almost half of them are in sub-Saharan Africa. By the middle of the century, the population will no longer be able to reproduce itself. Only six countries will have a normal birth rate by 2100.
Some scientists see the decline in fertility as a good thing because explosive population growth increases environmental risks.
“We are not advocating to stop having children,” says lead author Chitra Saraswati of Australia. We are talking about expanding family rights, improving medicine, and welfare, the expert clarifies.
Russian researchers in the book “Revisiting the Limits of Growth” note that overpopulation is no longer a problem. “We are cautiously optimistic about the future,” they write. Most global challenges will be addressed to some extent, including climate change. According to the authors, humanity is moving towards a new global socio-economic system.
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