Elon Musk thinks the population will collapse. Demographers say it's not happening

China to allow parents to have up to three children 02:18 (CNN)Billionaire Elon Musk tweeted, not for the first time, that "population collapse due to low birth rates is a much bigger risk to civilization than global warming." Climate change is a serious problem facing the planet and experts say it's difficult to compare problems. What is clear, demographers say, is that the global population is growing, despite declines in some parts of the world, and it shouldn't be collapsing any time soon -- even with birth rates at lower levels than in the past. "He's better off making cars and engineering than at predicting the trajectory of the population," said Joseph Chamie, a consulting demographer and a former director of the United Nations Population Division, who has written several books about population issues. "Yes, some countries, their population is declining, but for the world, that's just not the case." Population projections by the numbers The world's population is projected to reach 8 billion by mid-November of this year, according to the United Nations. The UN predicts the global population could grow to around 8.5 billion in just 8 years. By 2080, the world's population is expected to peak at 10.4 billion. Then there's a 50% chance that the population will plateau or begin to decrease by 2100. More conservative models like the one published in 2020 in the Lancet anticipate the global population would be about 8.8 billion people by 2100. It's true that what's driving current population growth is not a higher birth rate. What drives global 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. That is expected to increase to 77.2 years by 2050. It now costs more than $300,000 to raise a child, thanks to inflation It now costs more than $300,000 to raise a child, thanks to inflation Globally, the fertility rate has not "collapsed," nor should it, according to the UN, but it has dropped significantly. In 1950, women typically had five births each; globally, last year, it was 2.3 births. By 2050, the UN projects a further global decline to 2.1 births per woman. In some countries, it is lower. In the US the 1950s, it was 3.6 births per woman, it slipped to 1.6 in 2020, according to the World Bank. In Italy, it was 1.2; in Japan, it was 1.3; in China, 1.2. In January 2022, the country announced the birth rate fell for the fifth year in a row, even with the repeal of the one child policy, allowing couples to have up to three children as of 2021. "Virtually every developed country is below two, and it's been that way for 20 or 30 years," Chamie said. Most countries have gone through what's called a demographic transition. Abortion laws impact people trying to become pregnant, too Abortion laws impact people trying to become pregnant, too The only continent that hasn't finished 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, children still face high death rates. The infant mortality rate for kids 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 could be addressed and the global population could decline further -- but people would be better off in terms of individual health. The 'gold medal' century In terms of population growth, the 20th century was an anomaly. "That century was the most impressive demographic century ever. It had more gold medals than all the other centuries," Charmie said. The human population nearly quadrupled, something that had never happened before in recorded history. That's largely because of improvements in public health. Elon Musk reportedly had twins with a Neuralink executive Elon Musk reportedly had twins with a Neuralink executive 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 oral pill was widely introduced in the US, couples were now better able to determine when and how many children they had. "Contraception, the oral pill had a much more significant effect on the world than the car," Charmie said. As more women got an education, worked outside the home and got a later start on children in many countries with access to contraception, couples had fewer children and the population started to decline. In 2020, the global population growth rate fell under 1% for the first time since 1950.