It’s become an accepted opinion that marine biologist Rachel Carson, the author of Silent Spring (1962), was the founder of the modern environmentalist movement. But this may very well be a myth. Recent historical scholarship suggests that this title more likely applies to controversial Stanford University biologist Paul Ehrlich, author of the 1968 best seller The Population Bomb.

What that means is that Ehrlich’s message that overpopulation was leading the planet to catastrophic famine, epidemics, and resource depletion may have done more to spark the environmentalist movement than any other issue, including Carson’s worries about the effects of synthetic pesticides and herbicides on the health of different species.

No one has bolstered the Carson myth more than former U.S. Vice President Al Gore, who contends that without Carson “the environmental movement might have been long delayed or never have developed at all.” In 1994, Gore wrote that reading Carson’s book had a profound impact on him, and that he has a picture of her hanging on his office wall. Her example, he claimed, inspired him to write his own book, Earth in the Balance (1992).

Others have echoed Gore’s viewpoint. It was her pioneering work that “gave birth to the environmental consciousness we have today,” her biographer, Linda J. Lear, asserted in 2005. In 2012, The New York Times declared that Carson “ignited the environmentalist movement.”

Statements such as these certainly enhance Carson’s legacy, but they are not in accord with historical reality. Historians such as Matthew Connelly, Donald Critchlow, Derek Hoff, and Thomas Robertson have documented the importance of the overpopulation issue—which Carson did not address at all in Silent Spring—in the origins of the environmentalist movement in the 1960s and 1970s.

Robertson argues that Ehrlich’s “flawed genius” was crucial, because few signs of an environmental movement existed before his The Population Bomb appeared in 1968—six years after Carson’s Silent Spring hit the bookshelves. Interestingly, Ehrlich’s best seller appeared at just about the time that, demographically speaking, the fertility of the American family had begun to decline. His advice to American couples to “stop at two” sought to spread awareness of increasing pressures of overpopulation on the natural world. To Ehrlich, overpopulation was the main cause of poverty, pollution, disease, malnutrition, and social injustice.

0221-EHRLICH-1Who was Paul Ehrlich? Born in 1929 to liberal, Jewish parents, he developed a keen interest in biology while growing up in Maplewood, New Jersey, a suburb outside Newark, where he spent hours and hours chasing butterflies and dissecting frogs. In 1957, he graduated from the University of Kansas with a Ph.D. in entomology and population studies.

Growing up in a Jewish family during World War II shaped Ehrlich’s later interest in civil rights. In 1959, as a postgraduate student, he joined anti-segregationist protests in Lawrence, Kansas. His commitment to racial justice affected his views on biology and the differences among species. Human beings, Ehrlich wrote, “are all brothers under the skin.”

Ehrlich’s research continued into the 1960s as he became increasingly fascinated with the study of animal populations and their interaction with their natural environments. A firm believer in Darwin’s theory of natural selection, Ehrlich grew convinced that human beings were subject to the same laws that determined the relationship between food supply and species survival.

Meanwhile, Rachel Carson was fast becoming a celebrity thanks to the publication of Silent Spring, which highlighted research linking the use of chemicals and cancer rates in American society. The book had a poignantly personal dimension for Carson who, as she labored to see it through to publication, knew she was dying of breast cancer. She also had to withstand criticism from other scientists in the field as well as attacks from the chemical industry, which questioned her theories about the harmfulness of insecticides, particularly DDT.

Her sickly appearance before a congressional committee in June 1963 to testify against pesticide spraying helped to make her look like a sympathetic, courageous, and credible public figure. A 1963 CBS television special report on her also enhanced her reputation, as did an endorsement of her work by John F. Kennedy’s administration.

By the time she died in 1964, Carson had won the public relations battle with Big Chemical. Still, the passage of time has not been kind to Silent Spring. The claim that she was the first to draw public attention to the toxic legacy of chemicals such as DDT is belied by the fact that conservationist author William Vogt, in his best-selling Road to Survival (1948) had issued the same warnings over a decade before Carson.

Today there does not appear to be a consensus about the dangers of DDT. The U.S. Environmental Protection Agency states on its website that “a relationship between DDT exposure and reproductive effects in humans is suspected, based on studies in animals,” but classifies DDT only as a “probable” human carcinogen, suggesting that the agency is hedging its bets.

Nor was Carson the first to popularize the idea of ecology, the notion that human beings are simply another species, which shares the same natural environment with other organisms. Prior to the 1960s, authors Vogt, Henry Fairfield Osborn, Jr., and Aldo Leopold had already used the concept in their writings.

The chapter in Silent Spring that caught the most attention was titled “One in Every Four,” in which Carson predicted that in time cancer would strike one in every four Americans. However, her thesis that most cancers were due to human exposure to chemicals in the environment has not been vindicated by later scientific research. Even in the early 1960s, the American Cancer Society’s own studies showed that cancer rates were inching up largely because of the aging of society. Additionally, the society said the only type of cancer whose incidence was genuinely on the rise was lung cancer and, as Carson should have known, research was beginning to link cigarette smoking to cancer.

Carson can be excused, perhaps, because she relied heavily on the research of scientist Wilhelm Hueper, a widely published pathologist who studied the occupational causes of cancer and denied that tobacco use was a major cause. But it was a major weakness in her argument.

While she was a celebrity for a brief period, the environmental movement did not quickly materialize as a result. Typically, its birth is traced to Earth Day, April 22, 1970, when thousands of Americans took to the streets in a massive environmental “teach-in,” but that was eight years after Silent Spring appeared in print.

More consequential in the minds of the public at the time was the 1968 publication of Ehrlich’s The Population Bomb, as shown by overpopulation as a central theme of Earth Day in 1970. Ehrlich, like many Americans, read Silent Spring and came away convinced that the misuse of pesticides constituted a grave danger to all animal creatures, including human beings. But Ehrlich also drew conclusions from Americans’ heavy reliance on synthetic chemicals, which Carson did not. Ehrlich argued that using herbicides and pesticides not only endangered human health, it also revealed the shortcomings of science to grow enough food to feed the world’s teeming populations.

By 1968, Ehrlich was under the sway of the theories of the 18th-century English economist Thomas Malthus, which stated that human population was destined to outstrip food supply. “The battle to feed all of humanity is over,” Ehrlich warned. “Hundreds of millions of people are going to starve to death.” Population growth was out of control, and needed to be stopped by mass birth control programs, by force if necessary. He didn’t rule out “various forms of coercion” to bring birth rates in line with death rates.

In the spring of 1968, with encouragement from the country’s foremost environmental organization, the Sierra Club, Ehrlich and his wife, Anne, hastily finished The Population Bomb in the hopes that its contents might affect the presidential election that fall. The rush to get the book into print and into the political conversation is evident from its cover, which shows a bomb’s fuse burning above a melodramatic caption: “THE POPULATION BOMB KEEPS TICKING.”

The book quickly made an impact: Ehrlich’s overwrought jeremiad sold over two million copies, and by 1971 had been reprinted 20 times. Television coverage ensured that Ehrlich’s message would spread further and wider than Carson’s. The medium was still in its infancy when she was writing. Six years later, television technology had penetrated the confines of almost all American homes. In February 1968, Ehrlich leapt to stardom when he appeared on NBC’s The Tonight Show, generating a deluge of letters from viewers—an unprecedented occurrence for the network. Over the next few years he returned to the show 18 times, becoming one of host Johnny Carson’s most popular guests.

Ehrlich’s stardom was brief but far-reaching. He was part of what historians call the “neo-Malthusian moment” in U.S. history: the years spanning the turbulent 1960s and the mid-1970s, when overpopulation debates were raging in the nation’s media and corridors of power. Hollywood picked up on the national angst, and produced films such as Soylent Green (1973) and Logan’s Run (1976), which depicted grim, futuristic scenarios of overcrowding and scarce resources.

0221-EHRLICH-2In 1968, Ehrlich helped to found the organization Zero Population Growth (ZPG), whose membership leapt to 35,000 by 1972. That same year ZPG (today rebranded as “Population Connection”) counted 400 chapters around the country. Its members were overwhelmingly young, white, male, and educated, and included luminaries such as folk singer Pete Seeger, entertainer Arthur Godfrey, and executive director of the Sierra Club David Brower. ZPG bumper stickers read “Stop Heir Pollution” and “Control Your Local Stork.”

Neo-Malthusianism dovetailed with events in the history of U.S. reproductive rights. In the wake of the U.S. Supreme Court’s 1965 ruling that married couples could buy and use contraceptives without government restriction, some states liberalized their laws limiting access to abortion, and in 1973 the Supreme Court ruled in Roe v. Wade that women enjoyed a constitutional right to abortion. Fears of a population explosion influenced the Court’s reasoning.

Yet Ehrlich’s support for “coercion in a good cause” when it came to preventing pregnancy drew the ire of feminists, who insisted that individual freedom (“choice”) be the overriding factor in the use of contraception. Also, in 1976-1977, Indian prime minister Indira Gandhi’s government imposed mass sterilization programs, affecting the lives of 7 million men and women. Gandhi’s policies triggered international protests and criticism of Ehrlich’s toleration of reproductive involuntarism.

Ehrlich also never recovered from the fallout from a celebrated 1980 wager he made with economist Julian Simon, who challenged Ehrlich on his prediction that the prices of valuable commodities would rise in the 1980-1990 period. Ehrlich bet that copper, chromium, nickel, tin, and tungsten would all rise in price. He lost the bet when the prices of all five dropped over the decade, despite the 1980s having witnessed the largest increase in global population in all of recorded history up to that point.

Ehrlich’s star may have been fading by the late 1970s, but the environmental movement was in full swing thanks to his consistent messaging that population and environmentalism were inextricably connected. Ehrlich and his wife remain stalwart backers of environmentalism, but have moderated their preaching about population control. Yet they continue to this day to defend the overall accuracy of their earlier predictions about mass starvation if world population isn’t reduced.

I’m guessing that Ehrlich’s picture doesn’t grace Al Gore’s wall along with Carson’s. But it should. Setting the historical record straight about Ehrlich is important. It’s important not because we should rehearse Ehrlich’s arguments in favor of population control today, nor question the sincerity of people like Gore who see history differently. It’s a matter of getting it right historically, and acknowledging Ehrlich’s impact on the origins of a movement that currently plays a powerful role in policy-making.

The ignorance in many environmentalist circles about the influence of Ehrlich may be either a case of wishful thinking or willful blindness. Or, it may simply be that environmentalists do not know the history of their own movement. At some stage in its development, the environmental movement earnestly rejected population as a root cause of environmental problems, and this may have led it to cover up its own history in a conspiracy of silence.

By way of analogy, consider the contemporary euthanasia movement, which distorts the past by its silence regarding its support for involuntary euthanasia of the handicapped in the 1930s and ’40s, a fact which was well-documented in the archives of the Euthanasia Society of America—at least until recently. Rumor has it that those records have been destroyed.

One thing is clear. The movement is entitled to think today that other factors are more consequential, but by denying the influence of Ehrlich’s theory of overpopulation, it runs the risk of whitewashing a past that was far more complicated than modern-day activists would have us believe.