Fertility rates in European countries are already below the global average, with the rates based on the number of children a woman will have in her lifetime.
ADVERTISEMENTAn overwhelming majority of countries globally will not have high enough fertility rates to sustain population size by 2100, according to newly published research in The Lancet.
The latest projections further highlight a "dramatic decline" in global fertility throughout this century that experts said has both "potential pros and cons".
Researchers led by the University of Washington’s Institute for Health Metrics and Evaluation (IHME) in the US found that three-quarters of countries will not have fertility rates high enough to sustain population size by 2050.
By 2100, they project that this will be the case in 97 per cent of countries, estimating that the global total fertility rate will drop from 2.23 births per female in her lifetime in 2021 to 1.68 in 2050 and 1.57 in 2100.
In developed countries, a rate of 2.1 births per person who could bear children over their lifetime is necessary to sustain population levels.
These projected rates do not "differ markedly" from the United Nations' population figures taking into account the margins of error, according to a comment attached to the study.
The UN said in 2022 that global fertility is projected to decline to 2.1 births per woman by 2050.
"The world's population is projected to reach a peak of around 10.4 billion people during the 2080s and to remain at that level until 2100," according to the UN’s 2022 population prospects.
What’s the situation in European countries?
The projected fertility rates in Central, Eastern, and Western European countries are all below the global average estimated for 2050 and 2100, and are already lower than what is needed to sustain population growth.
The total fertility rate in Western Europe is projected to fall from 1.53 in 2021 to 1.44 in 2050 and 1.37 in 2100.
Italy, Spain, and Andorra were projected to have the lowest fertility rates by then.
The rate in Eastern European countries is projected to fall from 1.38 in 2021 to 1.19 in 2100 and in Central European countries from 1.48 in 2021 to 1.21.
Ukraine, Serbia, North Macedonia, and Bosnia and Herzegovina were projected to have the lowest fertility rates in 2100, with all of them below one birth per female in her lifetime.
According to UN figures, Europe and Northern America are projected to reach peak population size in the late 2030s as fertility rates have been below two births per woman since the 1970s.
'Pros and cons' of low fertility rates
Gitau Mburu, James Kiari, and Pascale Allotey from the World Health Organization, who were not involved in the study, wrote in an independent comment published in The Lancet that the low fertility rates come with “potential pros and cons”.
Low fertility could have "benefits related to population growth, environment, food security, health, climate change, and biodiversity," the experts said, adding however that it could have negative effects on health care, pensions, social security, labour and geopolitics.
They warned that countries should not impose pro-natal policies in reaction to the projections, stating that declines in fertility should not be used to limit access to contraception or abortions.
Mburu added in an email to Euronews Health that multiple factors contribute to declining fertility rates including education, contraception access, and postponing parenthood. Economic factors, such as the cost of raising children and societal shifts in the labour force, can also play a role.
ADVERTISEMENTAccording to Stein Emil Vollset, a professor at IHME and senior author of the study, in some ways these falling rates are a “success story” that reflects “not only better, easily available contraception but also many women choosing to delay or have fewer children, as well as more opportunities for education and employment”.
'Staggering social change'
Vollset added however that the world faces "staggering social change through the 21st century" due to a "baby boom" in some countries and a “baby bust” in others.
The study found for instance that sub-Saharan Africa will account for "one in every two children born on the planet by 2100".
Overall the share of the world’s births in low-income regions will rise from 18 per cent in 2021 to 35 per cent in 2100, according to the projections.
This means, Vollset said, that "many of the most resource-limited countries in sub-Saharan Africa will be grappling with how to support the youngest, fastest-growing population on the planet in some of the most politically and economically unstable, heat-stressed, and health system-strained places on Earth".
ADVERTISEMENTMburu, Kiari and Allotey warned, however, that the finding also "requires nuanced interpretation" due to the uncertainty of births and problems with data in those regions.
The research is part of the Global Burden of Disease, Injuries, and Risk Factors Study (GBD) 2021 and received funding from the Bill and Melinda Gates Foundation.
The fertility forecasts up to 2100 were based on the average number of children born to women when they reach 50 years of age and took into account education, contraceptive needs met, population density, and child mortality.
