The man who bet against humanity — and lost

Paul Ehrlich was famous for predicting a population explosion that would destroy the planet, but he didn't count on human ingenuity. Guest: Bryan Walsh, Vox senior editorial director This episode was made in partnership with Vox’s Future Perfect team. For show transcripts, go to ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠vox.com/unxtranscripts⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ For more, go to ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠vox.com/unexplainable⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ And please email us! ⁠⁠⁠[email protected]⁠⁠⁠ We read every email. Support Unexplainable (and get ad-free episodes) by becoming a Vox Member today: ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠vox.com/members⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ Thank you! Learn more about your ad choices. Visit podcastchoices.com/adchoices

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• 1:30Speaker 02

  On February 9th, 1970, Johnny Carson did something that would be unthinkable for a late-night host today.

• 1:39Speaker 02

  He gave a full hour of The Tonight Show to a Stanford professor. But Paul Ehrlich, the author of the blockbuster book The Population Bomb, was charismatic, telegenic, and absolutely terrifying. Joined by his wife Anne, he told Carson's massive audience that hundreds of millions of people were about to starve to death and that nothing could stop it. Ehrlich's first appearance on The Tonight Show demonstrates a lot of things, not least how much popular TV has changed. I'm struggling to imagine Carson's eventual successor Jimmy Fallon giving an hour to, say, CRISPR inventor Jennifer Doudna, let alone without a lip sync battle. But it also shows just how influential Ehrlich was.

• 2:27Speaker 02

  Arelic appeared on The Tonight Show more than 20 times. The Population Bomb sold over 2 million copies and became one of the most popular science books of the 20th century. His works helped popularize a broader population panic worldview that influenced policymakers in the US and abroad, including coercive family planning policies in countries such as India and China. Arelic and his book fundamentally changed the world we live in today.

• 2:57Speaker 02

  And yet, Arelic, who died recently at 93, turned out to be spectacularly wrong, wrong in ways that have had major consequences for humanity. But I want to dwell on something. It's precisely because he was both so wrong and so influential that doomsaying remains so seductive and so dangerous.

• 3:34Speaker 02

  The Population Bomb, I suspect, was one of those of-the-moment books that was more owned than read. You didn't need to get far into it to grasp Arelic's alarmist message. You just needed to read the opening lines. Quote, "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." And the book was just part of his lifelong campaign. Arelic predicted that 65 million Americans would die of famine between 1980 and 1989. He told a British audience that by the year 2000, the United Kingdom would be, quote,

• 4:17Speaker 02

  "a small group of impoverished islands inhabited by some 70 million hungry people." He said India, which was home to nearly 600 million people in 1970, could never feed 200 million more people. He said US life expectancy would drop to 42 by 1980. On Earth Day in 1970, he declared that, quote, "In 10 years, all important animal life in the sea will be extinct." Every one of these predictions was almost 180 degrees in the wrong direction.

• 4:50Speaker 02

  In America, as in much of the world, obesity became the true metabolic health crisis, not starvation. The UK, at least the last time I checked, still exists. India is now a major agricultural exporter, and its population has nearly tripled, while hunger has fallen. Marine life is stressed, but very much not extinct. The bottom line is that instead of mass starvation, the world experienced the greatest expansion of food production in human history. Per capita calorie supply has risen consistently since 1961. Since "The Population Bomb" was published, rates of hunger have dropped dramatically. So what did Erlich miss?

• 5:34Speaker 02

  For one thing, he made a common mistake. He assumed "line goes up." The years leading up to "The Population Bomb's" publication in 1968 featured the steepest population increases in global history. The trends were so on the nose for his thesis that you could almost forgive Erlich for assuming they would inevitably continue. But if Erlich looked closer at the data, it would have revealed that even in the high-growth 1960s, the world was already bending toward our comparatively low fertility present. Europe, Japan, and North America were all seeing their fertility rates fall

• 6:15Speaker 02

  as societies urbanized, women were educated, and child mortality dropped. Plus, "The Population Bomb" was published in 1968, which was eight years after the birth control pill was introduced. Erlich, and many others of his time, to be fair, appeared to assume that these patterns wouldn't apply as the countries of the global south developed. But they did. As these social and economic trends spread around the world, fertility kept falling from around five children per woman globally when "The Population Bomb" was published, to 2.3 today. But the bigger mistake wasn't misreading data. It was failing to account for people.

• 7:00Speaker 02

  People like Norman Borlaug.

• 7:05Speaker 02

  Borlaug was an agronomist from rural Iowa who, with the support of the Rockefeller Foundation, developed high-yielding dwarf wheat varieties that transformed agriculture in countries like Mexico, India, and Pakistan. India, which Erlich had written off in racially tinge ways, didn't just avoid famine, it became self-sufficient in food production.

• 7:31Speaker 02

  The Population Bomb was explicit about Erlich's worldview. Population growth was the "cancer" that "must be cut out." He saw people, or at least people in the Global South, as little more than mouths to feed, each fighting for shares of static pie. And he dismissed the part the Global South could play in finding solutions.

• 7:58Speaker 02

  Borlaug and the Green Revolution researchers, by contrast, saw them as mines to solve problems, including figuring out ways to make that pie bigger. Erlich's fundamentally zero-sum worldview may have gotten him global recognition, and sadly, remains far too prevalent. But it blinded him to the future. And that's why he ended up on the losing end of one of the most famous wagers in academic history. We'll be back after a short break.

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• 11:59Speaker 04

  The end is coming! Did I miss it?

• 12:03Speaker 02

  Julian Simon, an economist at the University of Maryland, believed the opposite of everything Ehrlich believed.

• 12:12Speaker 02

  Simon's argument was simple: People are the world's most valuable resource. Human ingenuity responds to scarcity by finding new supplies, substitutes, and efficiencies. And that meant the commodity prices, adjusted for inflation, would fall over time, not rise. In 1980, Simon challenged Ehrlich to a bet: Pick any raw materials, any time period longer than a year, and wager on whether prices would go up or down. Ehrlich and two colleagues chose five metals: chromium, copper, nickel, tin, and tungsten, and bought 1,000 worth of them on paper. The bet would be settled in 1990.

• 12:58Speaker 02

  During those 10 years, the world's population grew by more than 800 million, the largest one-decade increase in human history.

• 13:10Speaker 02

  Ehrlich was wrong. Again, all five metals fell in inflation-adjusted price. In October 1990, Ehrlich acknowledged Simon's win with a check for $576.07.

• 13:27Speaker 02

  What Ehrlich didn't do was revise his views to reflect the facts, which is what makes him more than a cautionary tale about bad predictions. In 2009, he told an interviewer that the "population bomb" was "way too optimistic." In 2015, he said his language "would be even more apocalyptic today." On 60 Minutes, in 2023, at age 90, he told correspondent Scott Pelley that "the next few decades will be the end of the kind of civilization we're used to."

• 14:03Speaker 02

  It didn't matter that the world had spent 55 years proving him wrong. Ehrlich didn't blink.

• 14:12Speaker 02

  And Erlich's wrongness had real consequences. He endorsed cutting off food aid to countries he considered hopeless, including India and Egypt. The broader population panic movement he helped create influenced coercive, real-world policies. India's forced sterilization campaigns during the 1970s, China's one-child policy, and sterilization programs across the developing world. So why did the world listen to him for so long? Partly because we're wired to. Humans process negative information more readily than positive,

• 14:53Speaker 02

  an evolutionary hangover that makes doomsayers inherently more compelling than optimists. And a research on expert prediction found that, quote, "hedgehog thinkers," people who, like Erlich, see everything through the lens of one big idea and fight like hell to hold on to it, are simultaneously the worst forecasters but get the most media attention. They're more confident, more quotable, more dramatic. The hedgehog gets Carson. The fox gets ignored. There's also a structural incentive problem. Predict things will be fine, and you're wrong? You're irresponsible. Predict disaster, and you're right? You're a genius.

• 15:38Speaker 02

  Predict disaster, and you're wrong? People forget, or just assume you were a little early. It was notable to me, the sub-headline of the New York Times' obituary of Erlich called his predictions not wrong, but, quote, "premature." None of this means we should ignore environmental problems. Climate change is real, and Erlich was relatively early in flagging it. Biodiversity loss, which is closer to his actual academic expertise, remains legitimately alarming.

• 16:16Speaker 02

  And we shouldn't repeat Ehrlich's mistakes in the opposite direction. Just because things have been getting better does not automatically mean that trend will continue, especially if we make perverse and self-defeating policy choices. But the real lesson of Ehrlich's life is that assuming doom leads to worse policy than assuming agency. Right off a country is hopeless, and you justify cutting its food aid. Assume people are the problem, and you end up sterilizing them against their will.

• 16:57Speaker 02

  Julian Simon died in 1998, never approaching Ehrlich's level of public fame. His signature line, quote, "The ultimate resource is people, skilled, spirited, and hopeful people, who will exert their wills and imaginations for their own benefit as well as in a spirit of faith and social concern." You probably wouldn't have heard that on The Tonight Show, but it's the formula for a much better world.

• 17:40Speaker 02

  This episode was written by me, Brian Walsh. Production help from Amy Padula and Meredith Hadnot. Editing from Joanna Solotaroff, with mixing and sound design from Christian Ayala. Hosts Noam Hassenfeld and Sally Helm are off playing with magnets. And as always, thanks to Brian Resnick for co-creating the show. Byrd Pinkerton walked up to the wall in the station and ran her fingers on the crack. She started wondering whether she was even in the right place, when, suddenly, the wall pushed in, the crack opened up, and a talent reached out and grabbed her.

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