The number of children being born worldwide will drop dramatically by the end of this century, a study has predicted.
The global average fertility rate is forecast to fall from 2.4 children per woman in 2017 to 1.7 in 2100.
The prediction has huge implications for societies as the number of people of working age is dwarfed by the elderly population.
When the fertility rate falls lower than 2.1, the size of the population begins to fall. Many wealthier countries already have a figure below 2.1.
Writing in The Lancet on Wednesday, academics from the University of Washington's Institute for Health Metrics and Evaluation said many countries may be unable to pay for themselves in the short to medium term.
“Because of progress in female educational attainment and access to contraception contributing to declining fertility rates, continued global population growth through the century is no longer the most likely trajectory for the world’s population,” researchers wrote in the study, which was funded by the Bill & Melinda Gates Foundation.
“By contrast, world population might peak just after mid-century and substantially decline by 2100.
“Our forecasts for a shrinking global population have positive implications for the environment, climate change, and food production, but possible negative implications for labour forces, economic growth, and social support systems in parts of the world with the greatest fertility declines.”
Countries with already ageing populations and relatively low immigration from foreign workers were forecast to see the most dramatic slumps.
Japan and Italy, the countries with highest ageing populations, would be among those hardest hit.
Japan’s population is projected to fall from 128 million in 2017 to fewer than 53 million by 2100.
Italy would fall from 61 million to 28 million over the same years.
“That’s a pretty big thing; most of the world is transitioning into natural population decline,” researcher Prof Christopher Murray, one of the report’s authors, told BBC News.
“I think it’s incredibly hard to think this through and recognise how big a thing this is; it’s extraordinary, we'll have to reorganise societies.”
Is it too late to reverse the trend?
The study’s authors noted that several countries have made a significant push to improve fertility, with mixed results.
“Some, such as Sweden, Singapore and Taiwan have tried to create positive environments that facilitate females choosing to have more children,” they wrote.
“These programmes include paid maternity and paternity leave, protection of re-employment rights, child care and financial incentives for more children.”
Sweden’s total fertility rate rose from 1.5 in the late 1990s to 1.9 in 2019, though that was still below the 2.1 growth marker.
“By contrast, positive incentives have had little effect in Singapore and Taiwan, where 2017 TFR levels were 1.26 ... for Singapore and 1.04 for Taiwan.”
Can AI and robots help?
The authors noted that many wealthier societies may ease rules on immigration to bring more workers in, though they said that was not a long-term solution to the low birth rate.
One potential solution could lie in a technology that is only now becoming a reality.
“Developments in robotics and artificial intelligence, which have not been explicitly modelled in the economic forecasts, could substantially change economic growth,” researchers wrote.
“In the future, technological advances might provide a solution to the decline in the workforce.”
Immigration backlash
The Lancet study noted that wealthy countries – in particular Canada, Australia, New Zealand and the United States – that had pursued liberal immigration policies for the past 30 years could expect to have "sustained population growth" in the years to come.
But they highlighted the recent political backlash against immigration in the US that “threatens the country’s potential to sustain population and economic growth”.
Other countries that have resisted liberal immigration in recent years could fare the worst, with authors singling out Japan, Hungary, Slovakia and the Baltic states.
“The desire to maintain a linguistic and culturally homogeneous society has outweighed the economic, fiscal, and geopolitical risks of declining populations,” they wrote.
They concluded by saying governments still have time to act and that no country yet has its “demographic future cast in stone”.
