(CNN) — the billionaire Elon Musk tweetednot for the first time, that “population collapse due to low birth rates is a far greater risk to civilization than global warming.”
Climate change is a serious problem facing the planet and experts say it is difficult to compare the problems.
What is clear, demographers say, is that the global population is growing, despite declines in some parts of the world, and should not collapse any time soon, even with birth rates at lower levels than in the past.
“You’re better off doing cars and engineering than predicting the population trajectory,” said Joseph Chamie, a consultant demographer and former director of the United Nations Population Division, who has written several books on population issues.
“Yes, in some countries, their population is declining, but for the world, that is not the case.”
Population projections in figures
The world population is expected to reach 8 billion by mid-November this year, according to United Nations. The UN predicts that the world population might grow to regarding 8.5 billion in just 8 years.
By 2080, the world population is expected to peak at 10.4 billion. Then there is a 50% chance that the population will stabilize or start to decline in 2100. More conservative models, such as the one published in 2020 in the Lancetpredict that the world population will be regarding 8.8 billion people by 2100.
It is true that what is driving current population growth is not a higher birth rate. What drives the world’s population growth is that fewer people are dying young. Global life expectancy was 72.8 years in 2019, an increase of nine years since 1990. It is expected to increase to 77.2 years in 2050.
Globally, the fertility rate has not “collapsed”, nor should it, according to the UN, but it has dropped significantly.
In 1950, women used to have five births each; globally, last year, it was 2.3 births. By 2050, the UN forecasts a further global decline, to 2.1 births per woman.
In some countries, it is less. In U.S.A., in the 1950swas 3.6 births per woman, and fell to 1.6 in 2020, according to the World Bank. In Italy, it was 1.2; in Japan, 1.3; in China, 1.2. In January 2022, the country announced that the birth rate fell for the fifth consecutive yeareven with the repeal of the one-child policy, which allows couples to have up to three children from 2021.
“Virtually all developed countries are below two, and have been for 20 or 30 years,” Chamie said. Most countries have gone through what is called a demographic transition.
The only continent that has not completed this transition, he said, is parts of Africa, where there are 15 to 20 countries where the average number of children couples have is five. But in those countries, minors continue to have high mortality rates. The infant mortality rate for children under 5 is 8 to 10 times higher than in developed regions, and maternal mortality is more than double, Chamie said.
If women in these African regions had more access to contraception, education and health care, these problems might be solved and the world population might continue to decline, but people would be better off in terms of individual health.
The century of the “gold medal”
In terms of population growth, the 20th century was an anomaly.
“That century was the most impressive demographically. It had more gold medals than any other century,” says Charmie.
The human population almost quadrupled, something that had never happened in history. This is largely due to improvements in public health.
The world has antibiotics, vaccines, public health programs and improved sanitation to thank for people living longer and more mothers and children surviving birth.
With contraception, especially in 1964 when the birth control pill was widely introduced in the US, couples were better able to determine when and how many children to have.
“Contraception, the oral pill, had a much bigger effect on the world than the car,” Charmie said.
As a greater number of women educated, worked outside the home, and started having children later in many countries with access to contraception, couples had fewer children, and the population began to decline.
In 2020, the world population growth rate fell below 1% for the first time since 1950.
The outlook in the US
In the US, the fertility rate has dropped in part because of what Ken Johnson, a senior demographer at the Casey School of Public Policy and a sociology professor at University of New Hampshirecharacterized as a “significant” decrease in births as a result of teen pregnancies.
“Most demographers would see that as a good thing,” he said.
Johnson argues that the other factor is the decline in the number of births to women in their 20s. This trend has been going on since 2008. People postponed or decided not to have children in part because of the recession, he said. And covid came to aggravate that trend.
Between July 2020 and 2021, the US population growth rate was the lowest it has been in probably 100 years, he said.
“Is it a collapse in the number of births? No, I wouldn’t say that,” Johnson said.
Johnson said there are a few factors at play in America’s slow growth rate: fewer births, fewer immigrants due to Trump-era policies, and more deaths as the US population ages. Covid-19 also contributed to a higher number of deaths.
“It’s almost like a perfect storm, if you will,” Johnson said. “Births are down a lot, Covid is driving up the death toll, and then immigration is pretty slow, too, so it’s no wonder the population growth rate is so low when you put all those factors together at the same time. weather”.
Prevent population problems in the future
Population aging and declining birth rates in some parts of the world might strain social systems.
The percentage of the population over 65 years of age will go from 10% in 2022 to 16% in 2050. That means twice as many children under 5 years of age.
Globally, the trick to making this population age imbalance work is that governments will have to be proactive, the UN says. Countries with aging populations must adapt public programs that support this growing population of older people. That means strengthening programs like social security, pensions, and establishing universal access to healthcare and long-term care.
In the EU, William Frey, a demographer and senior fellow at Brookings Metro, said he doesn’t see a need for more couples having more babies to fix America’s age imbalance. Policies to support couples who want to have children like affordable childcare and family leave policies, for example, might help, but that hasn’t made much of a difference in terms of fertility rates.
Fertility is below replacement rate in the United States, meaning couples are having fewer than two children each, but the rate is not as low as in most of Europe, he said.
“I don’t think in the US it’s a matter of collapse, because we can certainly allow more immigrants in whenever we want,” Frey said. “We won’t have a shortage of people wanting to walk in the door to immigrate here in the future. Immigrants and their children are younger than the population as a whole, so that will help keep the population from aging as well.”