Paul Ehrlich, a Scientific/Environmental/Cultural Iconoclast (1932-2026)

He told the truth in the face of relentless, unfounded criticism

Famed Stanford biologist Dr. Paul Ehrlich passed away on March 13, 2026 at age 93. I mourn this loss because he was a genuine hero. He was catapulted into the national limelight by Johnny Carson, who had him as a guest on The Tonight Show 28 times. That made him the spokesman for our planet. Carson was genuinely interested in what Ehrlich had to say – largely about human overpopulation, but also overconsumption, after he and wife Anne penned the bestselling book, The Population Bomb.

“Few problems are less recognized, but more important than, the accelerating disappearance of the earth’s biological resources. In pushing other species to extinction, humanity is busy sawing off the limb on which it is perched.” - Paul Ehrlich

Paul wasn’t crazy about that title, but the publisher got the final say. In truth, the book was as much about overconsumption as about overpopulation. But it did inspire an active movement to address our ballooning numbers. Of course, growth profiteers – who wanted more customers, not fewer – attempted to discredit him.

“Anytime you hear anybody praising economic growth or population growth, you know you’re listening to somebody who can’t do arithmetic.” - Paul Ehrlich

Along with John Holdren (who was later director of the White House Office of Science and Technology Policy for U.S. President Barack Obama), Ehrlich came up with the famous IPAT equation: Impact (on the planet) equals Population times Affluence times Technology.

Eventually, even the Sierra Club, whose executive director David Brower had persuaded the Ehrlichs to write The Population Bomb, became reluctant to address the population issue. It became taboo because of misguided efforts by some to focus on the birth rates of the poor, or the dark-skinned people of the global south. There were also human rights violations of forced sterilizations or abortions, notably in China and India.

But the truth has always remained the truth – the Earth cannot sustainably support more than a few billion people, at most, living comfortable, decent lives. And addressing the population multiplier in the equation can be done humanely, ethically and voluntarily.

Paul Ehrlich didn’t shirk his responsibility to speak that truth. He usually did so with candor and color, and in spite of harsh criticism from profit-seeking growth pushers and from hyper-sensitive social justice warriors. The nuance (that we all have a responsibility to choose small families, regardless of our skin color or socio-economic status) was sadly lost on many.

“Growthmania is surely the most pervasive social disease in America…. Most economists are hooked on growth the way junkies are hooked on heroin.” - Paul Ehrlich

During his career, Ehrlich wrote more than 50 books and 1,000 scientific papers about population biology, entomology, ecology, environment and our culture. You’ll find a few reading recommendations in the show notes for the current episode of the GrowthBusters podcast.

He was one of the first interviews I did – in 2007 – for my documentary, GrowthBusters: Hooked on Growth. I interviewed Paul several more times since then, for the GrowthBusters podcast and a webinar or two. I’m honoring Paul Ehrlich’s memory on the GrowthBusters podcast by revisiting some of those interviews in the next few episodes. First up, that first interview, outside Paul’s Stanford University office. Only a few minutes of that interview made it into the GrowthBusters documentary (because I interviewed so many brilliant experts for the film), so I shared much more of that interview in an episode of the Conversation Earth syndicated radio series I hosted in 2015-2017. That’s what you’ll hear in episode 96 of GrowthBusters. Find it wherever you listen to podcasts.

I’ll never forget the morning after I sent Paul a link to preview the final cut of the film. He hopped on Skype with me, in his bathrobe at his home, to express his excitement. He gave me this quote to use in promoting the film:

“GrowthBusters could be the most important film ever made. It tackles the three lethal taboos that threaten our civilization, those against discussing overpopulation, overconsumption, and the nonsensical idea that economic growth itself is a net benefit even in rich countries and can and must continue forever.” - Paul Ehrlich

I confess that if no one else had praised or even bothered to view GrowthBusters: Hooked on Growth, the fact that Paul Ehrlich praised it made it worth all the effort.

The photo is from the author’s interview with Paul Ehrlich in 2007 at Stanford University.

Dave Gardner is founder and executive director of GrowthBusters.

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