by Fertility rates around the world are falling faster than expected, putting the world on track to see population decline before the end of the century, according to a United Nations report.
The population of more than 60 countries and territories has already peaked, including Italy, Japan, Russia and, in 2021, China, according to the report published on Thursday. That means that 1 in 4 people in the world live in a country that already has a peak population.
Changes in population growth and fertility rates are closely tracked because they have major social and economic implications around the world. The number of people on Earth also affects the planet itself, affecting consumption rates, energy use, industrial production, resource availability and thus, to some extent, the pace of human-caused climate change.
The current global fertility rate is 2.25 births per woman, one child per woman less than in 1990.
“The demographic landscape has evolved dramatically in recent years,” Li Junhua, United Nations Under-Secretary-General for Economic and Social Affairs, said in a news release.
The report predicts that the world’s population will continue to increase in the coming years – growing from 8.2 billion people in 2024 to a peak of almost 10.3 billion people in 50 to 60 years. But it won’t grow forever: The world population is expected to return to 10.2 billion people by 2100, which is 6% lower than UN experts predicted a decade ago.
The UN’s previous population assessment, released in 2022, suggested that humanity could grow to 10.4 billion people by the end of the 2000s, but birth rates are lower in some of the world’s largest countries, including China. among the reasons for the earlier than expected. population peak.
More than half of all countries have a fertility rate of less than 2.1 births per woman, or what is known as the “replacement rate,” because it is the number of children each woman would need, on average, to keep the population from declining. .
Forty-eight other countries, including Vietnam, Brazil, Turkey and Iran, are expected to see their populations peak in the next 30 years.
India’s population of 1.4 billion makes it the most populous country in the world, surpassing the population of China in 2022. India’s population is expected to continue to grow throughout the middle century, according to the report .
China’s population, however, is declining.
“The number of children born in China has declined very rapidly and significantly over the last few years,” said Patrick Gerland, head of the population estimates and projections division at the United Nations population division. .
“The changes happening in China within the last generation are some of the fastest in the world,” Gerland said.
If it weren’t for immigration, the United States would be facing population declines — it’s one of about 50 places estimated to be able to continue growing because of immigration gains. The US is projected to grow from 345 million in 2024 to 421 million by the end of the century.
The country’s growth is likely to increase issues around consumption, greenhouse gas emissions and other drivers of global warming. A larger population also means more people will be exposed to climate risks, such as droughts, heat waves and other extreme weather events that intensify global warming.
“Just because a challenge may be emerging six decades from now doesn’t mean it doesn’t make sense to talk about it now,” said Dean Spears, associate professor of economics at the University of Texas at Austin.
“Years from now, people will be talking about these new population changes, with the same level of scholarly and social interest that we now talk about climate change,” Spears said.
Other countries expected to continue to grow through 2054 include India, Indonesia, Pakistan and Nigeria. In some parts of Africa – including Angola, Central African Republic, Democratic Republic of Congo, Niger and Somalia – population is expected to grow rapidly, doubling between 2024 and 2054, according to the UN.
But adding more people to the planet will not necessarily increase the pace of climate change. Most of the fastest growing parts of the world are countries that have historically contributed the least to global warming. These same areas tend to be disproportionately affected by climate change.
The report noted a bounce back in life expectancy levels after the pandemic was contained. Worldwide, life expectancy in 2023 was 73.2 years. That’s up from a pandemic low of 70.9 in 2021 and higher than the pre-pandemic 72.4 five years earlier. Global life expectancy is expected to reach 81.7 years in 2100.
As life expectancy increases and fertility rates decrease, the world’s population will age. Projections show that there will be more people 65 and older than children younger than 18 by 2080. From 2023, almost 3 to 1 outnumber children 65 and older.
This article was originally published on NBCNews.com
