The Bomb That Never Went Off

Paul R. Ehrlich’s population bomb never exploded. Understanding why he was so wrong—and why it mattered so much—tells us more about ideology than demography.

by Kaiser Bauch

In October 1990, Paul Ehrlich mailed a check for $576.07 to Julian Simon, an economist at the University of Maryland he had compared to a flat-earther and whose views he said were as useful as astrology is to a nuclear physicist.

Ten years earlier, the two men had made a bet: Ehrlich chose a basket of five commodity metals—copper, chromium, nickel, tin, and tungsten—and wagered that their prices would rise by 1990, as a growing population would have strained the planet’s finite resources. The price of every single one had fallen. He sent the check and immediately argued, in print, that the bet had measured the wrong thing—then continued making essentially the same argument for another thirty-five years, until his death last week at 93.

Paul Ehrlich combined the rather unfortunate characteristics of a man who was objectively wrong in his famous predictions and was not really all that keen on admitting to his mistakes. He was a Stanford biologist by training, an entomologist who had spent years cataloguing butterflies in the Canadian arctic. Yet a sudden increase of public interest in lepidopterology was not the reason for Ehrlich’s fame.

It was his work in the domain of population studies, specifically in his famous prediction—summarised in the 1968 bestseller The Population Bomb—of a coming mass famine caused by the combination of exponential population growth and finite planetary resources. “The battle to feed all of humanity is over. In the 1970s and 1980s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now” is the first, rather alarmist, sentence of the book. Talk about hooking the reader right away.

In the 1974 follow-up The End of Affluence, he raised the stakes even more: “a situation has been created that could lead to a billion or more people starving to death… Before 1985 mankind will enter a genuine age of scarcity in which the accessible supplies of many key minerals will be nearing depletion.” By now you will have gotten the idea.

There are people who seem to have the bad luck of making a prediction that turned out to be wrong—or is assumed to have turned out wrong— a fact which can then be used against them every time they attempt to enter the public sphere. Francis Fukuyama could tell you all about it: on average, how much time passes between a major historical event and someone triumphantly declaring him a failure, even without having read his essay or book in question?

Paul Krugman, the Nobel Prize-winning economist, wrote in 1998 that “by 2005 or so, it will become clear that the Internet’s impact on the economy has been no greater than the fax machine’s.” But Krugman admitted he was wrong—and he did not advise governments to enact mass sterilisation by adding chemical castration agents to water supplies and staple foods. Paul Ehrlich was not one of these unfortunate figures who were always being reminded of their slip-ups, either perceived or real. His predictions were not of an overtly philosophical nature open to interpretation, as in Fukuyama’s case, nor a freely admitted mistake in a deliberately provocative article, as in Krugman’s. They were highly bombastic, alarmist, concrete and self-assured—and they led to concrete outcomes in public debate and policy.

An Old Mistake

Ehrlich’s ideas are often called neo-Malthusian, and for good reason—the parallels between Ehrlich and the British clergyman and economist Thomas Malthus are striking. In 1798 he published An Essay on the Principle of Population, in which he warned that population grows in a geometric progression while food production increases only arithmetically—making famine inevitable unless birth rates decline. He argued that poverty and misery are unavoidable, because a population will always push against the limits of the food supply.

Population therefore moves in self-regulating cycles: its growth will eventually hit the ceiling of what the ecosystem can sustain, at which point a series of catastrophes follows—famine, epidemic, and the like—shrinking the population, after which the whole cycle repeats itself. The irony connecting both Malthus and Ehrlich is that just as they made their predictions, technological progress was already underway that would render those predictions obsolete. The pattern Malthus described had been applicable in many cases before his time—essentially in the world of premodern agriculture. Yet just as he worked on his essay, the gears of the Industrial Revolution were beginning to turn—and with them, a broader transformation of agriculture and trade that would leave Malthus’s theory in the dust.

The Malthusian trap began to crack long before Malthus put his quill pen to paper. Between 1700 and 1900, crop yields in England roughly doubled—the product of centuries of accumulated agricultural knowledge. The seed drill replaced labour-intensive seeding by hand; the steel plough cut deeper and faster than anything that came before it; and the mechanical reaper allowed a single machine to harvest what had previously required dozens of labourers.

Soil exhausted by centuries of farming was replenished first by Peruvian guano, shipped across the Atlantic in vast quantities as fertiliser, and later by the emerging science of agricultural chemistry. Advances in food preservation meant that harvests no longer had to be consumed locally before spoiling. Railways and steamships did the rest—connecting surplus regions to those with deficits, turning food for the first time into a genuinely global commodity, and ensuring that a bad harvest in one country no longer meant starvation for another. Underpinning all of it was something Malthus had not accounted for: industrial nations, England first among them, were generating enough wealth from manufactured exports that they could simply purchase what their lands could not produce.

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Ehrlich’s predictions suffered a very similar fate. It is true that the population was seeing massive growth during his lifetime. When he was born in 1932, the world’s population stood at roughly 2.1 billion. When he published his most famous book in 1968, at 3.5. At the time of his death earlier this month, it stood at roughly 8.3.

The primary driver of this explosion was not increased fertility—fertility rates have historically always been high—but collapsing mortality rates. Technological progress in medicine, sanitation, agricultural science and chemistry caused mortality to fall sharply across global populations, and in the twentieth century, especially among the poorer countries of the global south.

On the medical side, vaccines against diseases like measles, diphtheria and polio, the mass deployment of antibiotics following the discovery of penicillin in 1928, the pasteurisation of milk, and the development of oral rehydration therapy to combat the effects of diarrhoea collectively eliminated infectious diseases that historically had killed millions of children.

On the agricultural side, the Haber-Bosch process of 1909—which synthesised nitrogen fertiliser from air and is estimated to have made it possible to feed an additional four to five billion people—combined with Norman Borlaug’s Green Revolution breeding of high-yield wheat and rice varieties in the 1950s and 60s meant that mothers in the developing world gave birth to stronger, better-nourished children with a higher chance of survival.

This alone exposes a fundamental flaw in Ehrlich’s thinking. If the population explosion was caused not primarily by higher fertility but by lower mortality, then the argument essentially says that lower mortality is bad because it could potentially lead to higher mortality. But if high mortality—caused by a combination of malnutrition, disease and hunger—was the primary constraint on population growth, the growing population itself is the primary signal that ecological barriers were already being pushed to far more generous levels. Moreover, population growth was peaking precisely as Ehrlich was working on his book, in the mid-1960s, after which it gradually began to decline—a process that has not stopped since.

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Ehrlich was thus writing his magnum opus amid peculiar conditions—the postwar baby boom, when population growth and fertility were unusually strong even throughout the developed world. This gave his thinking a sense of urgency to articulate what was essentially a negative utilitarian view: that it is more important to minimise the total amount of aggregate suffering than to maximise happiness. To never be born is preferable to dying a horrible death, as famine undeniably is. We can set aside the more philosophical questions—such as who is in a position to authoritatively calculate whether a two-year-old child has experienced enough happiness to outweigh the fact that it later died of hunger and being born was thus not worth it—and focus on the more concrete point: that people, as Ehrlich’s case shows, are generally not very good at predicting systems as complex as the interplay of human populations, planetary resources, and technological progress.

Ehrlich’s ideas were also clearly not ideologically neutral. He was a fierce critic of capitalism and consumerism, arguing that the affluent lifestyle of wealthy nations was depleting the planet’s resources as surely as population growth in the developing world did.

He favoured strong state intervention in economic and reproductive life—proposing that federal bureaucracies should have the power to regulate family size, impose tax penalties on large families, and if voluntary measures failed, resort to compulsory sterilisation. His solutions invariably demanded an expansion of government authority, whether over land use, consumption, or human reproduction. In the American political context of the 1960s and 70s, he was firmly associated with the countercultural left and the emerging environmental movement.

When Ideas Have Consequences

Did these anti-natalist ideas have a real impact? Without question. The antinatalist flavour he added to the environmentalist movement has never entirely left it—and the movement itself remains a significant force in public policy, particularly in Europe.

It profoundly shaped Western public opinion, especially among the more educated classes, and to this day a significant portion of people consider overpopulation the defining crisis of our time—despite mounting evidence that the developed world is moving in precisely the opposite direction. In the developing world, a series of aggressive population control policies were implemented, often closely aligned with the prescriptions Ehrlich and his contemporaries were advocating. Some were relatively benign: Iran, for instance, pursued a path of public education and voluntary incentives without state coercion, and successfully brought its fertility rate down without systematic abuses.

Elsewhere the picture was far darker. China’s one-child policy saw over 300 million women being fitted with intrauterine devices designed to be irremovable without surgery, over 100 million sterilisations, and over 300 million abortions—many of these procedures were coerced. The stories from that period are harrowing: women in the late stages of pregnancy were dragged to vans and subjected to crude forced abortions. Sometimes the baby was delivered alive, at which point the doctor would inject formaldehyde into the infant’s skull or crush it with forceps.

In India, more than 8 million men were forced to undergo vasectomies between 1975 and 1977, including 6 million in the single year of 1976, with nearly 2,000 dying from botched procedures. Health officials were denied their salaries until they met sterilisation quotas; teachers and policemen were similarly incentivised, while the poor, the illiterate, prisoners and homeless men were disproportionately targeted—herded onto buses and taken to makeshift clinics with no exceptions made for the unmarried or childless.

It would be unfair to hold Ehrlich personally responsible for these policies—he was far from the only influential anti-natalist voice of his era, and ultimate responsibility lies with the politicians and bureaucrats who ordered and carried out these measures. But one thing is beyond dispute: every single one of these states eventually came to regret what they had done.

As Iran’s fertility rapidly dropped below replacement level, Supreme Leader Ayatollah Khamenei publicly acknowledged the mistake in terms that were uncommon for him. In a 2012 speech, he said: “One of the mistakes we made in the ‘90s was population control. Government officials were wrong on this matter, and I, too, had a part. May God and history forgive us.” Iran today is among the fastest ageing countries on the planet.

China’s one-child policy may be among the biggest policy failures of the twentieth century. The Chinese population is projected to halve during this century, and comparison with culturally comparable societies—South Korea, Taiwan, Singapore—suggests that Chinese fertility would have declined to very low levels regardless. The one-child policy served largely to cement and accelerate a trend that was already underway.

As for India—the country about which Ehrlich wrote that it was “so far behind in the population-food game that there is no hope that our food aid will see them through to self-sufficiency”, that he had “yet to meet anyone familiar with the situation who thinks India will be self-sufficient in food by 1971”, and that it “couldn’t possibly feed two hundred million more people by 1980”—it achieved food self-sufficiency sometime in the 1970s.

It went on to add roughly 160 million people by 1980, and the population control programmes pushed by the World Bank and Lyndon Johnson’s administration produced only a political backlash and the electoral defeat of Indira Gandhi, the country’s prime minister.

Their demographic impact was negligible: between 1960 and today, India added over a billion people to its population regardless. In all three countries, there is no consensus that any famine would have occurred in the absence of these measures—and more importantly, fertility rates in all three were already beginning to decline, slowly but surely, driven by urbanisation, basic education, and broader social change.

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A Fair Question

It is important to acknowledge that the fears of Ehrlich, or those of Thomas Malthus, were not entirely unfounded. The basic premise—that there is some limit to how many people, with growing consumption levels, the planet can sustain—is an essentially rational one and must therefore be taken seriously.

Famines and epidemics were a common occurrence throughout human history, and nothing guarantees they will never occur again. Even Norman Borlaug, the American agronomist credited with saving over a billion people from starvation and dubbed the father of the Green Revolution, struck a cautionary note when accepting the Nobel Peace Prize in 1970: “The green revolution has won a temporary success in man’s war against hunger and deprivation; it has given man a breathing space. If fully implemented, the revolution can provide sufficient food for sustenance during the next three decades. But the frightening power of human reproduction must also be curbed; otherwise the success of the green revolution will be ephemeral only.” It is also true that billions of people still live in countries where, if circumstances took a turn for the worse, lack of water and food could produce tragedies the scale of which would be unfathomable.

At the same time, a growing number of countries face depopulation within the span of this century—which carries with it potentially dire consequences. The benefit of population decline in the developed world is usually justified by pointing to the high levels of consumption in these countries and the drain this places on global resources.

But the question can also be framed differently: the vast majority of the technological innovations that have repeatedly pushed the boundaries of human population limits have originated in a relatively small number of developed countries that now almost universally face dire demographic projections.

The idea that population growth in some countries might be more beneficial for humanity than in others is an ideological no-go zone for many people engaged with these questions—and perhaps for good reason.

One of the lessons we can take from Paul Ehrlich is that people are rarely able to transcend their conscious or subconscious ideological programming. What can seem—and may even be experienced by those who articulate it—as a utilitarian concern for the fate of the planet is often, to a large extent, a vehicle for other ideologies. That is true on both sides of the spectrum.

In some ways, Ehrlich’s worldview was ultimately conservative—not in the political sense, but in its belief that there is a limit to what humans can do when faced with challenges. How many times can humanity count on achieving the kind of groundbreaking technological progress that pushes the limits further out? That is a fair question, and someday humanity will find out. But one can also look at the question of human fallibility from a different angle—the limited ability of any human mind, even the most brilliant ones, to correctly evaluate complex systems as being far beyond our full understanding, given their interplay of human populations, planetary resources, and technologies we have not yet invented.

So far, the truth about the population bomb is that it never really exploded. While population growth over the past century was massive, it did not lead to a catastrophe—and it is now rapidly declining from year to year.

In the end, birth rates started to fall across the world—which is what Ehrlich wanted. Yet they had very little to do with fear of overpopulation. It was a combination of unpredictable socioeconomic and cultural factors, which we still do not completely understand, that led to the current state of affairs.

Today, it is easier to name regions where fertility remains above replacement level than those where it does not. This creates an interesting postscript to Paul Ehrlich’s legacy. There are many people who argue that alarm about population decline is unfounded, precisely because the population bomb episode shows us that all previous predictions were spectacularly wrong—and there is every chance it will be similar this time.

And while it might be surprising coming from me, there is something to that. Not that I believe we are close to a demographic turnaround in the countries suffering most acutely from these trends. But it is true that just as we failed to see the coming population decline and still do not fully understand its complex causes, our ability to correctly predict or influence future demographic outcomes remains severely limited. We can only wait to see what the future of humanity will be—and try to handle whatever comes as best we can.