According to a major study released by scientists, according to model analysis, the global population is expected to peak at 9.7 billion in the middle of this century, after which it began to shrink, to 8.8 billion people by the end of the century, 2.1 billion less than the United Nations forecast. The study predicts that a new pattern will emerge globally due to declining fertility rates and an aging population.
According to Agence France-Presse reported on July 15, researchers at the University of Washington's Institute for Health Indicators and Evaluation (IHME) published in the latest issue of the British magazine "The Lancet" (The Lancet) report that by the end of this century, 183 out of 195 countries will fall below the threshold needed to maintain population levels.
Populations in more than 20 countries, including Japan, Spain, Italy, Thailand, Portugal, South Korea and Poland, will be reduced by at least half. At the same time, forecasts show that in 80 years Chinese mouths will fall from today's 1.4 billion to 730 million.
However, sub-Saharan Africa's population will triple to about 3 billion, and Nigeria alone will expand to nearly 800 million in 2100, becoming the second most populous country in the world, after India, the world's most populous country, with a population of 1.1 billion.
Professor Christopher Murray, head of the research group, said: "These projections are good news for the environment, with less pressure on food production systems, lower carbon emissions and important economic opportunities for parts of sub-Saharan Africa. ”
"However, most countries outside Of Africa will see a decline in the workforce and an inversion of the population pyramid, which will have a profound negative impact on the economy."
The study predicts that as global fertility rates decline and life expectancy increases, the number of children under the age of 5 will decline from 681 million in 2017 to 401 million in 2100, which is expected to fall by more than 40 percent, while the number of people over 80 years old will surge from about 140 million today to 866 million. By the end of the century, more than a quarter of the world's population, or 2.37 billion people, will be over 65 years old.
The sharp decline in the number of people in the labor force will also pose a huge challenge for many countries, Murray said, "which will lead to huge social changes." "In a severely ageing world, humanity needs to rethink a range of questions, such as who pays for the taxes, who pays for health insurance for the elderly, who cares for the elderly and at what age to retire?
The global population is currently around 7.8 billion. The United Nations predicts in 2019 that the population will grow to 8.5 billion, 9.7 billion and 10.9 billion in 2030, 2050 and 2100, respectively.
The difference between the UN and IHME data depends heavily on fertility. The global fertility rate has decreased significantly in recent years, from 2.4 in 2017 to below 1.7 by 2100. It is generally assumed that if the fertility rate drops below 2.1, the population begins to decrease.
"Our analysis shows that as women's education and access to reproductive health services increases, they choose to have fewer than 1.5 children on average," Murray explains. "Continued global population growth this century? This will no longer be the most likely trajectory for the world's population. ”
Founded in 2007 and supported by the Bill & Melinda Gates Foundation, IHME has become an important reference for global health statistics, particularly its annual Global Burden of Disease Report.
Compiled/written by: Nandu reporter Shi Minglei
Image credit: AFP
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