World population reaches seven billion: predictions of doom are nothing new
By Tom Chivers
Thomas Malthus predicted that humanity would face starvation. So far, he’s wrong
The world’s population will soon pass a new milestone. Previous dire predictions of mass starvation as human numbers have exploded have not come to pass, but can we be confident that will always be the case? Tom Chivers considers where earlier projections erred and what the future holds.
In 1798, an English clergyman, the Rev Thomas Malthus, predicted that one day the population of the world would outstrip the globe’s ability to feed it. He based this on a simple and, on the face of it, unarguable premise: population grows exponentially – increasing by a set percentage per year – while food production grows arithmetically, by a set quantity per year. Even the smallest exponential progression will, given enough time, outstrip any arithmetical one. Eventually, by the relentless laws of mathematics and demography, humanity would overreach itself and face mass starvation.
His warnings were echoed nearly two centuries later, by an American academic, Paul Ehrlich. His 1968 book, The Population Bomb, warned that by the end of the 20th century, humanity would face a population explosion followed by a sudden, devastating collapse. The book opened with the words: “The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate.” He predicted four billion deaths, including those of 65 million Americans. The book was a huge success, making Prof Ehrlich a global celebrity. He wasn’t alone in his predictions: the year before, two American brothers, William and Paul Paddock, had written another smash hit, Famine – 1975! Malthusian collapse was big box office.
According to the United Nations Population Fund, global population will reach seven billion. That’s more than double what it was when The Population Bomb was published. The world is growing by 80 million people per year – more than two every second. Clearly, the dire predictions of Malthus and Ehrlich have not come to pass: England and America are not starving, and there has been no great population collapse. So what has happened?
In short: technology. Malthus was wrong not because of his mathematics, but because of his inability to see into the future. His belief that humanity’s ability to feed itself would grow only arithmetically did not take into account – how could it? – the rise of agricultural efficiency, of industrial farming, of fertilisers and chemicals. At the time he wrote, 20,000 square metres of agricultural land were required to feed one person. In 2002, that figure was 2,000 square metres.
By the time Ehrlich wrote in 1968, industrial farming was widespread: still, he predicted a nightmare far more imminent and inevitable than any of Malthus’s claims. But Ehrlich was even more dramatically wrong. In the 43 years since he set down his terrifying vision, population has doubled: but not only has the world not starved, the amount of food available per head has increased by more than a quarter. According to the UN, the percentage of the population which is “undernourished” has fallen from 33 per cent to 16 since 1968. Global food production has easily kept pace with population: again, thanks to advances in agricultural technology, specifically those which drove the so-called Green Revolution. Through aggressive use of selective breeding and agricultural chemicals, and the development of new breeds of wheat and rice, what seemed to be looming disaster was averted. Rice yields per hectare in Asia tripled, and food costs plummeted. The “father of the Green Revolution”, an American agronomist and plant geneticist called Norman Borlaug, won the Nobel Peace Prize. He was described as the “Forgotten benefactor of mankind” by Atlantic Monthly, and credited having prevented a billion deaths.
That Malthus and Ehrlich were both so wrong is a tribute to human ingenuity. It’s also a warning to those who try to forecast the future. Neither of them predicted the revolutions in food production. Neither did they foresee another, even simpler, change in human behaviour: a global drop in fertility. The average woman now has just 2.52 children – down from 4.85 when Ehrlich was writing. In Europe and the United States, that has dropped to 1.53 and 2.07 respectively. This is thanks to contraception, to greater urbanisation and economic development, and to the education of women.
However, the fact that previous soothsayers have been wrong does not mean that the future is necessarily secure. It means that humanity is overconfident in its ability to predict it. Dan Gardner, the author of Future Babble, a book about the unreliability of such predictions, points out that it’s not new: “If you look at the history of demographic predictions, they are not only often wrong, they are routinely wrong. And we swing from one to the other: we swing from fear of overpopulation to underpopulation and back again. If you go back to the 1930s, you’ll find many smart people – George Orwell among them – saying that it’s terrifying that Britain will be completely depopulated by the 1980s.”
It wasn’t just the doomsayers in the 1970s who were making bad guesses. “As well as the Malthusians like Ehrlich, there was another group, the Cornucopians, who claimed ‘Ehrlich and the rest are wrong: don’t worry, everything’s going to be great,’ ” says Gardner. “Now, things turned out OK, but for completely different reasons from the ones the Cornucopians suggested.” Among their more “goofy” theories was a suggestion that undersea kelp farms would solve the food crisis.
“If people had said ‘human ingenuity is a magnificent thing, and in the face of necessity who knows what we’ll come up with’, that would have been exactly right,” says Gardner. “Unfortunately, that’s not what the Cornucopians said. What they said was ‘here is how we are going to fix it’, and they were wrong. It’s the mirror image mistake of Ehrlich and the Malthusians: complete overconfidence in their ability to predict future events.” They just didn’t make as much of a splash. “If you want to sell books, don’t be an optimist,” Gardner points out.
As we reach the seven billion mark, both camps are still in action, predicting either doom or plenty. Matt Ridley, the author of The Rational Optimist, is probably the most well known of the modern Cornucopians: Paul Ehrlich, meanwhile, still flies the flag for the Malthusians, saying as recently as 2009 that The Population Bomb was “too optimistic” about the future, and that since it was published there have been “famines, essentially continuously in parts of Africa”. While his prediction of billions of deaths has not come to pass, “300 million people overall have died of hunger and hunger-related diseases” since 1968. He added that “the world now may be on the brink of another major rise” in the death rate from starvation.
So what does this tell us about the world that lies ahead for baby number 7,000,000,000? Mainly that humans will continue to make bad predictions. The UN projects population reaching a peak of 9.22 billion in 2075, but as Gardner says: “Demography is a wonderful field that provides a lot of insights, but it is not a crystal ball: any sort of projection that goes out to, say, 100 years is essentially a guess.”
Making predictions, though, is not without consequence. “If you want Ehrlich’s worst prediction,” says Gardner, “I can summarise it in one word: India.” In 1974, Ehrlich, and the Paddocks, thought that India was doomed, and soon. But they didn’t think that the world should work to save it: they suggested a system of “triage”, in which rich countries should stop sending money to the terminal cases and try to save the others. Luckily, they were not listened to: the scientist who introduced Borlaug’s Green Revolution to India, Prof Monkombu Swaminathan, says that if they had been, tens of millions might have starved. Instead, India is one of the few countries whose economies are booming: it is now a major donor, rather than recipient, of food aid. “These overconfident predictions could have destroyed India,” says Gardner. “This is not an academic issue, or a ha-ha-you-lost-we-won thing, this is serious stuff.”
We must not be complacent: more than a billion people worldwide are starving or undernourished, and the world’s population is growing by more than 200,000 people a day. Human ingenuity is needed now as much as ever. But the seven billionth human is not necessarily a harbinger of disaster: and anyone who confidently says otherwise doesn’t know what they’re talking about.