The Vindication of a Public Scholar

Forty Years After The Population Bomb Ignited Controversy, Paul Ehrlich Continues to Stir Debate


photo of a couple in an officeAnne HamerskyPaul and Anne Ehrlich at their office
in Palo Alto, CA

It is 3:30 on a February afternoon at the Hyatt Classic Residence, an elegant retirement home adjacent to the Stanford University campus, and the auditorium is packed with people listening with rapt attention to a tall, slender man. He speaks rapidly into a wireless microphone with a gruff, forceful voice that still has a tinge of his East Coast youth. Ceaselessly striding back and forth across the stage, stopping only occasionally for a sip of water, he explains that he must keep moving or his back will give him fits. He has no notes. He has given variations of this talk many hundreds of times.

The speaker is Paul Ehrlich, a professor of population biology at Stanford, and a resident, with his wife, Anne, at the facility. During the last four decades, Ehrlich has been attacked – sometimes from within the scientific community, but mostly from outside it – for speaking out about the big environmental issues that face humanity, most notably the ever-increasing number of humans. Though buffeted by controversy, Ehrlich has lost none of the zeal that has made him a lightning rod for the sort of anti-science ideologues who held sway in the federal government for the past eight years. He isn’t shy about speaking his mind. “Mellow” is the last word you’d use to describe Paul Ehrlich.

He regales his audience with a short summary of human evolution: “We all came from black ancestors” and “Language with syntax is what separates us from all other animals.” The themes come from the Ehrlichs’ latest book, The Dominant Animal, which is a fascinating examination of human cultural evolution and other topics. He then moves to the present: “Nothing has happened on climate change except talk.” He’s concerned with studies that suggest the altered climate will require major revamping of our water delivery systems – dams, canals, reservoirs – for irrigation and direct consumption, and that we don’t have enough backhoes or enough gravel for constructing the sea walls that will have to be built as a defense against rising tides. He speaks for an hour, scarcely drawing a breath. After the talk, he is surrounded by people wanting to ask questions.

Early in his Stanford career, Ehrlich taught a class in human evolution. The last week of lectures involved the professor’s thoughts on the direction humankind was headed. He told his students that he saw an ever more crowded planet, a dwindling food supply, and an impoverished natural world. The class was popular, and he began receiving invitations to speak at conferences and other gatherings. In April 1967, he was invited to address the Commonwealth Club in San Francisco. When Ehrlich accepted, he did not know that the talk would be broadcast on the radio. The speech and its re-broadcast were a hit, and soon thereafter he received invitations to be interviewed on radio and television.

Not long after the Commonwealth Club speech, the late David Brower, executive director of the Sierra Club and later the founder of Earth Island Institute, switched on the television at home one day, and saw a Stanford professor on a daytime chat show talking about the population explosion, about the scourge of pesticides, about threats to the atmosphere, about how agriculture was falling behind in its quest to provide sufficient food for all. Brower picked up the phone and made some calls to track down Ehrlich. When he finally found him, Brower said, “Dr. Ehrlich, you have to put your story into a book.”

“Too busy,” Ehrlich said. “I’m flattered by the suggestion, but I really don’t have time.”

Brower then phoned Ian Ballantine, frequently credited with inventing the paperback book, and suggested that he try to persuade Ehrlich to write something. Ballantine had been publishing mass-market books with the Sierra Club for a few years, and had also published the Club’s calendars, which Ballantine said had made him rich. Ballantine got in touch with Ehrlich and eventually convinced him that writing a book would be worth his time.

Paul and his wife Anne immediately set to work, and in “a month of evenings” had a manuscript that had been carefully reviewed by a team of peers, mostly at Stanford. The Ehrlichs suggested it be called Population, Resources, and Environment, and shipped it to New York. Ballantine loved the manuscript, but hated the title. He also insisted on a single author even though Anne had been a full partner in the writing – a little merchandising sexism. Ballantine said The Population Bomb would be a far zippier title, and the book was published in mid-1968.

The Population Bomb was an immediate sensation, eventually selling some three million copies. The radio host Arthur Godfrey, a major figure back in the day, sent a copy to Johnny Carson, who invited Ehrlich to appear on “The Tonight Show” – which he did, more than 20 times. During Ehrlich’s first appearance, Carson allowed him to make a pitch for a new organization he had helped establish. It was called Zero Population Growth (ZPG), and Ehrlich gave out the address and asked people to join. Two days later, more mail arrived at the Los Altos, CA post office where ZPG was located than on any previous day in history. ZPG quickly grew to 600 chapters and a membership of 60,000. Ehrlich was eventually invited to become a correspondent for NBC News, with which he would travel the world, sometimes taking six months to produce a five-minute piece. The young Stanford prof was becoming downright famous. His explosive book had made many people scared about Earth’s future – and had made many others angry.

Paul Ehrlich was born in 1932 in Philadelphia to a shirt-salesman father and a schoolteacher mother. He spent summers in New England and during his vacations became fascinated with butterflies, especially their colors and markings. The Ehrlichs moved to New Jersey when he was nine, and as a teenager he took to raising butterflies at his home. But he ran into trouble because so much DDT was being sprayed for mosquito control that the plants local butterflies fed on were becoming poisonous to the insects. This was the beginning of his awareness of humans’ ability to do accidental harm to the natural world.

In the ‘50s, Ehrlich helped desegregate Kansas with a series of sit-ins called “Profitless Lunch Days.”

Ehrlich went to college at the University of Pennsylvania and then graduate school at the University of Kansas (KU), where he earned his PhD in 1957. His research included studies on the effect of pesticides on insects, specifically how they could evolve resistance to the chemicals. That and his New Jersey experience made him pay close attention when, in 1962, Silent Spring, a book that helped nurture his ecological thinking, was published.

One day in the student union at KU, Ehrlich joined a bridge game. Among the players was an undergraduate named Anne Howland. He was immediately attracted to her, and was dismayed to learn that she, a French major, was dating a French student. But the Frenchman returned to France when his one-year fellowship was over. Paul and Anne became fast friends and in less than a year had decided to marry (“The smartest thing I ever did,” he says). Paul proposed that the wedding take place at 2:00 p.m. on December 18. Anne’s parents insisted they wait until June. The couple compromised by delaying the ceremony until 4:00 p.m.— on December 18.

The couple, who just celebrated their 54th anniversary (they followed their own advice, and produced just one child, a daughter named Lisa), has a professional and intellectual partnership as well as a romantic one. The Population Bomb was a joint effort in a lifelong collaboration between the two. They work, as Paul says, “seriatim” – in sequence. “We work together, but not in each other’s laps,” he says. He’ll start a chapter, she’ll finish it, and vice versa. Such cooperative enterprises can be tricky, but theirs works beautifully. Whoever makes the final pass through the manuscript makes it all sound like a single voice. In general, it’s Anne – she pays attention to the mechanical stuff, “like spelling and grammar,” Paul says.

The collaboration that went public with The Population Bomb actually began much earlier. Before she became a lay scientist, Anne (once an art major) made the illustrations for Ehrlich’s PhD thesis. “The art experience allowed me to segue into science as a scientific illustrator,” she says. Anne now holds a position as a senior research scientist at Stanford, though her only degree, apart from two honoraries, is in French. The other research scientists are almost all PhD scientists.

Aside from being the place he met his wife, Lawrence, Kansas – where KU is located – was also a crucible of his commitment to progressive ideals. In the early ‘50s, Kansas was still largely segregated. One weekend, a UN official from Jamaica, a dark-skinned gentleman, arrived for a science conference and was put up in a local hotel. But the hotel wouldn’t serve him in the dining room. When he went looking for food Saturday morning, he was turned away by all the restaurants he tried to get into and was obliged to subsist on candy bars from vending machines.

Ehrlich and Professor Ralph Barr, a parasitologist, learned of the episode the following Monday. Soon after, they organized a band of students – black and white – to enter and occupy all the seats in one of the town’s eateries. The students wouldn’t be served, but no one else would either, and the restaurant would make no money. “Profitless Lunch Days,” they called them. After a few of these lunch-counter protests, the restaurants rescinded their whites-only policies.

Upon earning his doctorate, Ehrlich accepted a two-year post-doc at the Chicago Academy of Sciences, but returned to KU after one year to complete the post-doc when his advisor, Joseph Camin, transferred to KU to replace Ralph Barr on the faculty. After some frustrating job-hunting, Ehrlich won a position on the faculty of Stanford University, a position he would hold for 50 years and counting.

The relationships Ehrlich forged with faculty and students during his early days at Stanford read like a who’s who of the scientific and environmental activist communities. Among his colleagues in the 1960s was botanist Peter Raven, who would go on to become the esteemed head of the Missouri Botanical Garden. Among the students were Denis Hayes, who organized the first Earth Day in 1970, and Stewart Brand, who would invent and publish a series of Whole Earth Catalogs, an irregular and eclectic publication that defies description.

photo of people examining a magazine togetherCourtesy Anne Ehrlich. Photo originally appeared in LOOK magazine.Paul (L) and Anne reviewing proofs of their 1970 book Population,
Resources, Environment. The two have a professional as well as
romantic partnership and write, as Paul says, “in sequence.”

Another encounter at Stanford would have a major impact on Ehrlich’s life and work. After the publication of The Population Bomb, Ehrlich carried on a feisty argument in the Stanford Daily with a demography professor whose views on the population explosion were drastically at odds with his own. The letter exchange caught the eye of a graduate student in physics named John Holdren, and Holdren’s wife, Cheri, suggested that her husband get in touch with Ehrlich, which he did. As Ehrlich tells the story, Holdren brought a sandwich to Ehrlich’s office, and by late that afternoon, they had developed an outline for a paper, “Population and Panaceas,” which would be published in Bioscience in 1969. It was the first of many collaborative projects and the beginning of a fast friendship that would include summer stints at the Rocky Mountain Biological Lab in Colorado and occasional Christmases together. Cheri Holdren would later earn her PhD in biology under Ehrlich. John Holdren would create the Energy and Resources Group at Berkeley, teach at Harvard, run the Woods Hole Biological Laboratory, and serve a term as president of the American Association for the Advancement of Science. In late 2008, President Barack Obama tapped him to be his science advisor. “Obama’s so lucky to have him,” Ehrlich said when the nomination was announced. “He’s the smartest environmental scientist in the world.”

But before The Population Bomb made him a well-known figure on the Stanford campus and beyond, Ehrlich mostly kept himself busy with his investigations into the evolution of butterflies, doing research at the university’s Jasper Ridge Reserve. Most days would start with Ehrlich, Raven, and a few others having coffee at a round wooden table in the lounge in the biology museum. One day, Ehrlich was wondering aloud at the fact that the butterflies he was studying fed on a kind of snapdragon and on a species of plantain as well. Raven replied that it wasn’t odd at all, since plantains are simply wind-pollinated snapdragons. This got them to musing about what they might learn about the interaction between butterflies and their food sources. There are between 14,000 and 15,000 species of butterflies, of which nearly half have been carefully studied, owing to the millions of amateur and scholarly butterfly collectors around the world who raise butterflies from infancy, and need to know what the larval stage feeds on before it forms a pupa and eventually emerges as an adult butterfly.

Ehrlich and Raven combed the literature and eventually discovered that the insects and the plants were coevolving simultaneously, trying to get a leg up on one another. The host plant would slowly evolve a poison to discourage the butterflies, and the butterflies would evolve a defense to the natural pesticide. The scientists wrote up a paper called “Butterflies and Plants: A study in coevolution,” which appeared in the journal Evolution in 1964. The paper went on to become one of the most frequently cited papers in the discipline, and helped establish the study of coevolution as a major field of research within biology.

Stewart Brand, who was studying tarantulas on Jasper Ridge as Ehrlich and Raven were revolutionizing the field of biology, was impressed along with everyone else. “Up until then, evolution was generally considered a one-way street,” he told me. “Coevolution made the study of biology reflexive. Darwin had spoken of coadaptation, but no one had followed the story far until Ehrlich and Raven.” It was a major insight, Brand says, “especially since four out of five organisms are parasitic.” After the Whole Earth Catalogs ran their course, Brand started a magazine called CoEvolution Quarterly, now known as Whole Earth Review. The table over which the theory was hatched has been moved to Jasper Ridge, where it holds a place of honor.

Ehrlich is not shy about speaking his mind: “Anne is the brains,” he told me. “I’m the mouth.” He has an undeniably abrasive manner, sarcastic and cutting, and a wicked sense of humor. Once a questioner asked if Ehrlich had said that a taxonomist could be replaced by a computer. “No,” Ehrlich replied, “an abacus.” Given the controversy his work has attracted, this combativeness has served him well.

The Population Bomb made some radical predictions. “The battle to feed all of humanity is over,” it begins. “In the 1970s and 1980s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.” Almost immediately, the book – and its author – began to take fire. The book so incited Charles McCabe, a columnist for the San Francisco Chronicle, that he wrote 14 columns attacking Ehrlich between 1970 and 1982, calling him “Dr. Doom” and “the Cassandra of the contraceptive set.”

One of Ehrlich’s first lengthy public arguments about population and sustainability occurred with the biologist Barry Commoner. Bomb had suggested that population couldn’t continue to grow forever, that the planet was overpopulated already, and it might well take government intervention to slow and eventually reverse population growth. Commoner accused Ehrlich (and Holdren and many others) of being anti-poor people, concerned more with letting the rich stay rich and limiting development in the Third World. “He was basically a Marxist,” Anne says, “and he couldn’t accept the idea of population limitation.” Commoner’s book The Closing Circle included a fairly fierce attack on Ehrlich, and argued that a “demographic transition,” in which people in poor countries would slow their population growth as they became less poor, would take care of the problem.

This intellectual debate degenerated into farce at the United Nations environment conference in Stockholm in 1972. Organizers of the nongovernmental forum that occurred parallel to the official conference tried to set up a debate between the combatants, but Commoner refused. So the forum organizers set up a discussion with Ehrlich and two pro-Commoner panelists. The night of the panel discussion, the crowd was boisterous. As the program got underway, four anti-Ehrlich activists invited themselves onto the stage and proceeded to hector Ehrlich as Commoner passed handwritten notes and questions from the balcony to allies in the audience. Ehrlich finally called out, “Come on out, Barry baby!” to no avail. Anne sat cringing in the audience with Herman Daly, the economist and author of Steady-State Economics. The panel ended in chaos.

“Anne is the brains,” Paul says. “I’m the mouth.” Given the controversy his work has attracted, this combativeness serves him well.

Another (in)famous confrontation occurred between Ehrlich, Holdren, and John Harte (a colleague of Holdren at Berkeley) on one side and Julian Simon, a professor of business administration at the University of Maryland, on the other. Simon had made some truly astonishing statements: that the ability of Earth to provide materials for the use and enjoyment of humans is functionally infinite, for one. We’ll never run out of anything, Dr. Simon would say, and go on to say that Ehrlich and his colleagues were flat wrong when they asserted that a growing population would inevitably use up resources necessary for survival.

To emphasize how confident he was in his rosy scenarios, Simon proposed a bet. He said that between 1980 and 1990, the price of each of five metals – chromium, copper, tin, tungsten, and nickel – would fall, thereby demonstrating that supplies would be more, rather than less, plentiful. The bet was for $1,000 ($200 for each metal). Ehrlich, Holdren, and Harte were a bit chary of the deal. The five metals, they felt (and said at the time) were not reliable indicators of the state of resources and the environment. They would have preferred to bet on the relative health of groundwater, soils, forests, and species diversity as a measure of the deteriorating state of Earth’s life-support system. But on balance, after consulting many colleagues, the chance to shut Simon up for a decade and perhaps even show him up was too tempting. They took the bet.

It turned out not to be the smartest move. Prices of all five metals had risen in the 25 years previous to the bet, but a recession in 1990 suppressed demand for metals, among many other commodities. Also, a doubling in the cost of oil in 1979 drove up the price of the metals just as the bet was going into effect. Simon won on three of the five metals and collected a check for a bit over $500, calculated on the change in value of the three.

In 1995, Simon issued another challenge, this time via the San Francisco Chronicle. He wrote, “Every measure of material and environmental welfare in the United States and in the world has improved rather than deteriorated. All long-run trends point in exactly the opposite direction from the projections of the doomsayers.” He challenged his adversaries to bet that “any trend pertaining to material human welfare” would get worse.

Ehrlich and Stephen Schneider, a Stanford climatologist, offered to bet $1,000 each on 15 trends: 2002 to 2004 will be warmer than 1992 to 1994; tropical forests will decline; ocean fisheries will decline; there will be fewer plant and animal species in 2004 than in 1994; human male sperm counts will continue to decline, and so on. Simon blinked and withdrew his challenge.

Was Ehrlich’s first bet a mistake? Yes, because it was a propaganda bonanza for the forces that utterly refuse to face up to the fact that Earth and its resources are finite. The likes of Rush Limbaugh and Ann Coulter (Ehrlich calls them “random ignoramuses”) still love to bring up the bet – and did so most recently when Holdren was appointed science advisor to Barack Obama. But Ehrlich insists he doesn’t give a fig for what right-wing yahoos may say about him and his work. “If scientists began to say that I was off base, I would certainly pay attention,” he says. “Scientists care what other scientists say, not the lunatic fringe.”

book cover thumbnail, words: the Population Bomb - while you are reading these words, four people will have starved to death. Most of them children

Those scientists, meanwhile, have given Ehrlich most of the prizes they have to bestow, including the Crafoord Prize of the Royal Swedish Academy, which is equivalent to the Nobel, since there is no Nobel for ecology, evolution, or environmental science. He is a fellow of the American Academy of Arts and Sciences and a member of the US National Academy of Sciences. He received a MacArthur Foundation “genius grant” two decades ago. He has written or coauthored nearly 50 books (many with Anne) and another 900-plus papers and articles and essays. To paint him as a dangerous kook (“worse than Hitler,” in the words of Charles McCabe) is plain ridiculous.

Ehrlich is ever the iconoclast. He is by no means sure that climate change is the biggest challenge facing humanity – a position that is now bedrock in the mainstream environmental movement. Toxics could be worse, he says. There are some 100,000 toxic chemicals loose in the environment, many doing serious damage to natural systems, habitats, and species, and they are scarcely studied, let alone regulated. One problem that is not new but is essentially impossible to confront is that when two or more of these chemicals interact, they can produce totally unexpected results, and the potential number of combinations of these chemicals is virtually infinite.

When asked about the new administration and the overwhelming challenges it faces – global warming, a crumbling economy, fluctuating gas prices – Ehrlich is hopeful, but cautious. He insists, for example, that bailing out Detroit is a fine idea so long as Detroit agrees to build rail lines and train cars rather than automobiles. He scoffs at the arguments over whether to drill for oil in the ocean or the Arctic National Wildlife Refuge. “We shouldn’t be burning fossil fuels no matter where they’re found.” He worries that the old guard, personified by Larry Summers – Obama’s chief economic advisor and Commerce Secretary under Bill Clinton – may be allowed to steer recovery efforts in such a direction that we’ll rebuild the economic system that got us into the environmental fix we find ourselves in today. “Larry Summers may be smart enough to get it going again and too stupid to understand we don’t want it going again,” he says.

And then there’s the planet’s population, which is still growing and still very much on Ehrlich’s mind. The problem is not just raw numbers – it’s numbers multiplied by consumption. The US now has less than five percent of the world’s population and consumes about 25 percent of its resources. If the world’s people all consumed like Americans, we’d be done for quickly. Controlling numbers, as difficult as that is, is easier than controlling consumption, Ehrlich thinks.

Reflecting on the warnings he made 40 years ago, Ehrlich acknowledges that he and Anne underestimated the success people would have developing higher-yielding grains, and how that spurred further population growth. But he also points out that there have been perhaps 300 million deaths since Bomb was published that were caused in large part by malnourishment and undernourishment. He claims that the success of the “green revolution” of the 1970s is already running into the difficulties he and others predicted, while global hunger is now increasing. And he likes to remind people that Bomb included a carefully worded caveat about the scenarios it sketched out: “Remember, these are just possibilities, not predictions. We can be sure that none of them will come true exactly as stated, but they describe the kinds of events that might occur in the next few decades.”

For all of the things the popular book got wrong (or had mistimed), it got many other issues right. The book, which was about so much more than simply population, remains impressively prescient. “All of the junk we dump into the atmosphere, all of the dust, all of the carbon dioxide, have effects on the temperature balance of the Earth,” the Ehrlichs wrote, long before the risk of global warming was understood. The book spoke of the scourge of pesticides and Rachel Carson’s Silent Spring. And it made this outrageous assertion: “If our current rape of the watersheds, our population growth, and our water use trends continue, in 1984 the United States will quite literally be dying of thirst.” This was clearly premature, but here’s what the Web digest Earth Week, a valuable summary of scientific observations, said on March 7, 2009: “A warming and drying climate across the southwestern United States could eventually make major cities in the region uninhabitable. . . .With severe drought from California to Oklahoma, a broad swath of the Southwest is basically robbed of having a sustainable lifestyle.”

In retrospect, Ehrlich feels that The Population Bomb was “way too optimistic.”

Lester Brown, founder of the Worldwatch Institute and now head of the Earth Policy Institute, argues that what the Ehrlichs did in The Population Bomb was recognize earlier than most the threat of rapid population growth from an ecological point of view. It’s still a huge problem, though it has essentially disappeared as an issue, he says. “Some say Paul was and is wrong about this,” Brown says, “but most don’t realize how tenuously we’re still here. The population is sustained by unsustainable trends – overfishing, pollution, soil erosion, dying coral reefs. Not one has been turned around. Could food shortages bring down civilization? That’s what happened to the Sumerians, the Mayans, the Easter Islanders.”

Peter Raven, his longtime friend and colleague and co-inventor of coevolution, insists that Ehrlich is one of the most thoughtful people he has ever met, as well as one of the kindest.

“Paul always had a gruff exterior, but he’s the most considerate person I’ve ever known,” he says. “Heart of gold. He takes care of people. He’s been a tremendous influence for good. I regret that The Population Bomb has been parodied mercilessly by people who don’t know what they’re talking about. It was a wonderful wake-up call.”

So does Ehrlich have any regrets? Things he’d have done differently?

“I wish I’d taken more math in high school and college. That would have been useful.” And if he were writing The Population Bomb now, he’d be more careful about predictions. But he remains proud of the book and the controversy it stirred, the attention it brought to the issues discussed in the book, including population, consumption, and the overarching phenomenon of exponential growth. He still believes that the optimal population of the Earth would be 1.5 to 2 billion. Today, there are more than three times that many people alive, and the number keeps growing.

I ask what he most hopes he’s wrong about. He says, “I hope the future doesn’t turn out to be as bleak as it looks from here. I want my grandchildren to have a good life.”

Tom Turner is editor-at-large for Earthjustice and the author of Roadless Rules – The Struggle for the Last Wild Forests (Island Press, 2009).

Funding for this article came, in part, from members of, a new organization dedicated to grassroots funding of community journalism.

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