If the 20th century was an era obsessed with the fear of a global population explosion – a time when governments, experts, and journalists fretted that population growth powered by high birth rates would soon outstrip the planet’s finite resources – the 21st century promises to be the opposite, a time when fears focus on the world’s population growing older and smaller.
As experts begin studying the coming implosion, the tendency thus far has been to emphasize the negative. We read about falling government tax revenues, less productivity and innovation, strained finances, depopulated militaries, and small families struggling to care for more numerous and longer-living older relatives. But that is only one part of the possible future. As we start preparing for the coming changes – and prepare we must – some humility is in order, for two reasons. First, many of the demographic prognoses that dominated headlines in the last century proved wrong. And second, if there is one constant running through all of history, it is that humans are remarkably ingenious and adaptable. There are thus good reasons to believe that we will avoid disaster this time too – that a shrinking world may prove just as manageable as a growing one did.
Older and fewer
Low birth rates are the sole reason we are heading toward global depopulation. Humanity’s life expectancy at birth has never been higher; in 2023, according to the U.N. Population Division (UNPD), the average lifespan worldwide was 73 years.
The UNPD also estimates that more than 70% of humanity now lives in countries with below-replacement fertility rates – that is, childbearing patterns insufficient to assure long-term population stability in the absence of compensatory migration. On every continent but Africa, fertility levels have fallen below the replacement level, generally benchmarked at 2.1 births per woman during her lifetime. And birth rates are continuing to decline almost everywhere.
The UNPD anticipates that the global population will peak in the year 2084 – at least, that is its current “medium variant” projection. Under this scenario, close to 40% of the people currently alive – a little over 3 billion people – will live to see that momentous demographic turning point. By the UNPD’s “low variant” projection, on the other hand, human numbers will top out in the year 2053 – roughly a generation from now. If that version of the future comes to pass, more than 6 billion people alive today, or almost three-quarters of our current population, will still be around when the planet begins its depopulation.
But the world’s population could start shrinking even sooner than that. Childbearing rates are currently plunging to levels that demographers would not have deemed possible just a few years ago. In the Indian city of Kolkata, for example, the fertility rate has reportedly fallen to one birth per woman – less than half the replacement rate. Bogota, Colombia, is now down to 0.9 births per woman. Last year, South Korea hit a fertility rate of just 0.72 births per woman – barely a third of the level necessary to maintain its population. We don’t know how far such extremely low birth rates will spread, or how low fertility can go. But since recent developments have already taken us into a demographic reality almost no one would have imagined even a decade ago, it would seem incautious to assert that no further surprises lie ahead.
Read the rest of this piece at The Bush Center.
Nicholas Eberstadt holds the Henry Wendt Chair in Political Economy at the American Enterprise Institute (AEI), where he researches and writes extensively on demographics and economic development generally, and more specifically on international security in the Korean peninsula and Asia. Domestically, he focuses on poverty and social well-being. Dr. Eberstadt is also a senior adviser to the National Bureau of Asian Research (NBR).
Photo: Riba, a medical robot that is intended to assist nurses with patient care. Ars Electronica via Flickr under CC 2.0 License.
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