For many years it seemed that overpopulation was the looming crisis of our age. Back in 1968, the Stanford biologists Paul and Anne Ehrlich infamously predicted that millions would soon starve to death in their bestselling, doom-saying book The Population Bomb; since then, neo-Malthusian rumblings of imminent disaster have been a continual refrain in certain sections of the environmental movement – fears that were recently given voice on David Attenborough’s documentary Life on our Planet.
At the time the Ehrlichs were publishing their dark prophecies, the world was at its peak of population growth, which at that point was increasing at a rate of 2.1% a year. Since then, the global population has ballooned from 3.5 billion to 7.67 billion.
But growth has slowed – and considerably. As women’s empowerment advances, and access to contraception improves, birthrates around the world are stuttering and stalling, and in many countries now there are fewer than 2.1 children per woman – the minimum level required to maintain a stable population.
Falling fertility rates have been a problem in the world’s wealthiest nations – notably in Japan and Germany – for some time. In South Korea last year, birthrates fell to 0.84 per woman, a record low despite extensive government efforts to promote childbearing. From next year, cash bonuses of 2m won (£1,320) will be paid to every couple expecting a child, on top of existing child benefit payments.
The fertility rate is also falling dramatically in England and Wales – from 1.9 children per woman in 2012 to just 1.65 in 2019. Provisional figures from the Office for National Statistics for 2020 suggest it could now be 1.6, which would be the lowest rate since before the second world war. The problem is even more severe in Scotland, where the rate has fallen from 1.67 in 2012 to 1.37 in 2019.
Increasingly this is also the case in middle-income countries too, including Thailand and Brazil. In Iran, a birthrate of 1.7 children per woman has alarmed the government; it recently announced that state clinics would no longer hand out contraceptives or offer vasectomies.
Thanks to this worldwide pattern of falling fertility levels, the UN now believes that we will see an end to population growth within decades – before the slide begins in earnest.
An influential study published in the Lancet last year predicted that the global population would come to a peak much earlier than expected – reaching 9.73 billion in 2064 – before dropping to 8.79 billion by 2100. Falling birthrates, noted the authors, were likely to have significant “economic, social, environmental, and geopolitical consequences” around the world.
Their model predicted that 23 countries would see their populations more than halve before the end of this century, including Spain, Italy and Ukraine. China, where a controversial one-child per couple policy – brought in to slow spiralling population growth – only ended in 2016, is now also expected to experience massive population declines in the coming years, by an estimated 48% by 2100.
It’s growing ever clearer that we are looking at a future very different from the one we had been expecting – and a crisis of a different kind, as ageing populations place shrinking economies under ever greater strain.
But what does population decline look like on the ground? The experience of Japan, a country that has been showing this trend for more than a decade, might offer some insight. Already there are too few people to fill all its houses – one in every eight homes now lies empty. In Japan, they call such vacant buildings akiya – ghost homes.
Most often to be found in rural areas, these houses quickly fall into disrepair, leaving them as eerie presences in the landscape, thus speeding the decline of the neighbourhood. Many akiya have been left empty after the death of their occupants; inherited by their city-living relatives, many go unclaimed and untended. With so many structures under unknown ownership, local authorities are also unable to tear them down.
Some Japanese towns have taken extreme measures to attract new residents – offering to subsidise renovation expenses, or even giving houses away to young families. With the country’s population expected to fall from 127 million to 100 million or even lower by 2049, these akiya are set to grow ever more common – and are predicted to account for a third of all Japanese housing stock by 2033.
As the rural population declines, old fields and neglected gardens are reclaimed by wildlife. Sightings of Asian black bears have been growing increasingly common in recent years, as the animals scavenge unharvested nuts and fruits as they ripen on the bough.
Closer to home, in the EU, an area the size of Italy is expected to be abandoned by 2030. Spain is among the European countries expected to lose more than half its population by 2100; already, three- quarters of Spanish municipalities are in decline.
Picturesque Galicia and Castilla y León are among the regions worst affected, as entire settlements have gradually emptied of their residents. More than 3,000 ghost villages now haunt the hills, standing in various states of dereliction. Mark Adkinson, a British expat who runs the estate agency Galician Country Homes, told the Observer that he had “more than 1,000” abandoned villages on his books, adding that a staff member of his was continually on the road, leaving letters at abandoned properties in the hope of tracking down their owners and returning them to the market.
“I’ve been here for 43 years,” he said. “Things have changed considerably. The youngsters have left the villages, and the parents are getting old and getting flats closer to the hospital. You don’t want to get stuck up in the hills when you can no longer drive.”
As in Japan, nature is already stepping into the breach. According to José Benayas, a professor of ecology at Madrid’s University of Alcalá, Spain’s forests have tripled in area since 1900, expanding from 8% to cover 25% of the territory as ground goes untilled. Falling populations would continue to trigger land abandonment, he said, “because there will be fewer humans to be fed.”
France, Italy and Romania are among countries showing the largest gains in forest cover in recent years, much of this in the form of natural regrowth of old fields. “Models indicate that [afforestation of this kind] will continue at least until 2030,” Benayas said.
Rural abandonment on a large scale is one factor that has contributed to the recent resurgence of large carnivores in Europe: lynx, wolverines, brown bears and wolves have all seen increases in their populations over the last decade. In Spain, the Iberian wolf has rebounded from 400 individuals to more than 2,000, many of which are to be found haunting the ghost villages of Galicia, as they hunt wild boar and roe deer – whose numbers have also skyrocketed. A brown bear was spotted in Galicia last year for the first time in 150 years.
A vision of the future, perhaps, in a post-peak world: smaller populations crowding ever more tightly into urban centres. And outside, beyond the city limits, the wild animals prowling.
Cal Flyn’s new book, Islands of Abandonment: Life in the Post-Human Landscape, is out now (William Collins, £16.99)