Are there billions more people on earth than we thought? If so, it's no bad thing

The Guardian

31-05-2025

According to the UN, the world's population stands at just over 8.2 billion. However, a recent study suggests the figure could be hundreds of millions or even billions higher. This news might sound terrifying, but it is important to remember that anxieties about overpopulation are rarely just about the numbers. They reflect power struggles over which lives matter, who is a burden or a threat and ultimately what the future should look like.
The world's population reached 1 billion just after the turn of the 19th century. The number of people on the planet then began to grow exponentially, doubling to 2 billion by about 1925 and again to 4 billion about 50 years later. On 15 November 2022, the UN announced the birth of the eight billionth human.
As it is not possible to count every single person in the world, the UN's population figures are calculated by dividing the Earth's surface into a grid and using census data to estimate how many people live in each square. This method provides a rough estimate, but until now it was thought to be reasonably reliable.
A recent study by Dr Josias Láng-Ritter and his colleagues at Aalto University in Finland discovered that UN estimates undercount the number of people living in rural areas by more than 50%. This is because census data in the global south is often incomplete or unreliable outside big cities. Consequently, UN figures probably underestimate the world population by hundreds of millions or several billion.
Many people argue that our planet does not have the resources to support 8 billion people. 'Overpopulation' is seen as the root cause of many of the world's biggest problems. But these concerns are nothing new.
In 1988, the US sci-fi writer Isaac Asimov used what he referred to as 'my bathroom metaphor' to illustrate his fears about population growth. 'If two people live in an apartment, and there are two bathrooms, then both have what I call freedom of the bathroom.' But if 20 people live in the same apartment, they will impinge on each other's liberty one way or another.
According to Asimov, rapid population growth creates a similar problem. It not only places enormous pressure on natural resources, but also erodes autonomy, dignity and civility. 'As you put more and more people on to the world, the value of life not only declines, it disappears.'
At the turn of the 19th century, when there were fewer than a billion inhabitants on Earth, Thomas Malthus was already convinced that 'the period when the number of men surpass their means of subsistence has long since arrived'. Malthus's inability to predict that technology would revolutionise food production did not dent his popularity. On the contrary, as the world population grew, the prophets of doom grew ever louder.
Neo-Malthusian anxieties reached fever pitch with Paul and Anne Ehrlich's The Population Bomb – subtitled Population Control or Race to Oblivion (1968). This hugely influential, bestselling book warned: 'The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death.'
These devastating predictions encouraged governments and international agencies to take drastic action. As fertility rates were already falling in most high-income countries, these efforts concentrated on Africa and even more so Asia. USAID funded family planning programmes across what was then referred to as the developing world. Millions of Indian men were sterilised during the Emergency of the mid-1970s. In 1979, the Chinese Communist party introduced the one-child policy and a few years later launched a mass sterilisation campaign, which focused mainly on women.
Today, plenty of people remain concerned about overpopulation, but their apocalyptic visions now concentrate on climate change, resource depletion and biodiversity loss. Despite stark disparities in consumption – Americans consume 360 times more carbon per capita than Somalis, for example – population control still focuses on the majority world.
Thankfully, the coercive policies that took place in India, China and elsewhere are no longer in vogue. The new approach to population control focuses instead on women's empowerment. Educating women and giving them control over their lives has proved remarkably effective at reducing fertility rates. In the 1960s, women had on average five children each. Today, the figure is 2.3 per woman – just over what is needed to keep the population stable. By 2100 the global birthrate is projected to fall to 1.8.
According to the UN, the world's population will peak at about 10.3 billion in the mid-2080s. After this it will stabilise, then fall. The exponential growth that gave Malthusians so many sleepless nights has been halted. That many people will put considerable stress on the Earth's resources, but if consumption is managed responsibly and sustainable technologies are developed, the world will avoid an apocalyptic catastrophe.
Returning to Asimov's bathroom metaphor, as anyone who has crammed into one house with their extended family over Christmas knows, many people sharing few bathrooms creates a suboptimal situation. You won't be able to shower exactly when you want – and you'd better make it a short one. But this hardly amounts to the end of civilisation. In fact, compromise and sharing is probably closer to most people's idea of a good life than having the freedom to do whatever you want, whenever you want.
Population growth varies starkly between regions. In most high-income countries, fertility rates are already well below the replacement level. The African continent is projected to account for over half the world's population growth in the next three decades, with Asia and Latin America responsible for the rest.
As the historian Alison Bashford points out, concerns about overpopulation are often not really about there being too many people but too many of the wrong kind of people. Ethnonationalists in Europe and North America see the disparities in birthrates as an existential threat to 'western civilisation'. They worry about their countries being indelibly changed by mass migration. But the cold hard truth is that in a few decades our shrinking, ageing societies will desperately need these newcomers to pay taxes and work in healthcare and social care. This vision of the future may be unsettling for some, but the alternative is much worse.
To extend Asimov's metaphor, the populist right advocates a sort of bathroom apartheid. They are en suite isolationists, who want to retain exclusive use over one of the bathrooms in the apartment, and force the 19 other flatmates to share. At first, this approach has its advantages. They can soak in the bath all day. They can sit for hours on the can reading the news.
But sooner or later they will come a cropper. Perhaps the other toilet becomes blocked and the whole flat is inundated with raw sewage. The other flatmates might forcibly seize control of the personal bathroom. Or as the en suite isolationists grow old and infirm, they'll find themselves with no one to bathe them or wipe their bottoms.
Jonathan Kennedy teaches politics and global health at Queen Mary University of London, and is the author of Pathogenesis: How Germs Made History