Stanford University biologist , who , in Palo Alto, California, was a scientific crusader whose dire predictions about population growth, world hunger and environmental collapse made headlines and sparked controversy for decades.
Sometimes called a “” by his detractors, Ehrlich was among the most public figures of the environmental movement. He was admired and often . But he was also excoriated when his .
Ehrlich founded Stanford’s in 1984 and wrote more than 40 books and on ecology, the environment and population dynamics. He is best known outside of academia for writing “” in 1968, along with his wife, conservation biologist , who survives him.
The book became a bestseller that was reprinted and translated into multiple languages. It starkly predicted that population growth would , leading to wars and social collapse.
Ultimately, the book both popularized and polarized the U.S. environmental movement.
As a scholar of , I see Ehrlich’s difficult fight for the environment as emblematic of the vast chasm between science on one side and political culture influenced by the mass media on the other side.
And I see Ehrlich’s passing — along with others of his generation, such as , and — as a loss for a world that needs visionaries and public scientists now more than ever. Public understanding of science and technology is critical for political discussion, for environmental preservation and, in the words of British physical chemist , for the sake of “the poor if there is intelligence in the world.”
The battle over the book
“The Population Bomb” opened with a verbal blast: “The battle to feed all of humanity is over.” And because the “stork had passed the plow,” the Ehrlichs wrote, “hundreds of millions of people are going to starve to death.” Overpopulated India was doomed, they contended, and England “will not exist in the year 2000,” following a massive social and environmental breakdown.
These stark warnings, while overstated, seemed at least plausible at the time. Older scientists, including Snow and oceanographer , had also warned about overtaking .
The Ehrlichs by books such as the 1948 bestsellers “,” by ecologist , and “,” by paleontologist . All of these thinkers owed a debt to the original Cassandra of population catastrophe, English economist , whose 1798 book “” warned that the world’s population would inevitably outstrip its food supply.
Even worse, Malthus predicted, efforts to produce more food would simply continue the cycle of famine and poverty. However, new crops and agricultural techniques in the 19th century. As a result, the term “Malthusian” came to signify about complex social problems.
Paul Ehrlich appears on ‘The Tonight Show’ with host Johnny Carson on Jan. 31, 1980.
A different sort of Malthusian
Handsome and well-spoken, Ehrlich captured the public imagination through news articles, public lectures and television appearances. “The Population Bomb” launched him into the center of a raging global debate over environment and conservation. He appeared as a guest on “The Tonight Show” with Johnny Carson in the 1970s and early ’80s.
This wasn’t the typical public profile for a biology professor. As New York Times reporter Robert Reinhold , Ehrlich was “representative, perhaps, of a growing new breed of scientists who are willing to get involved in the unscientific and sometimes rough business of crusading in public against such things as DDT, highway building and population growth.”
Not all environmental advocates agreed with Ehrlich’s view that population growth was the critical threat. Another prominent biologist, , saw as the primary source of environmental problems.
In fairness, Ehrlich and his frequent collaborator, physicist , saw technology and population as , which they summarized with the equation I = P x A x T, or Impact equals Population times Affluence times Technology. Put another way, population growth, wealth and the types of technologies people chose to use all contributed to human impacts on the environment.
The debate between Ehrlich and Commoner perplexed some people, but it showed two different approaches to environmental policy. With Commoner’s approach, technological problems such as toxic waste and nuclear radiation, would be solved through cleanups and improved processes.
Ehrlich said reducing overconsumption and addressing population growth would also help ease these challenges. To slow population growth, Ehrlich called for , and perhaps even resorting to .
By the 1970s, a focus on population growth had become widely accepted. The first , held in Stockholm in 1972, ranked population growth alongside pollution and underdevelopment as the top action items on the global agenda. Later that year, a prominent European think tank, the Club of Rome, echoed Ehrlich’s warnings in its widely circulated report.
Scarcity or abundance?
World population continued to grow through the 1970s and ’80s, but the impacts that Ehrlich predicted did not occur. This was largely due to the , a broad campaign by governments and research institutes to provide high-yield varieties of wheat and rice, along with pesticides and mechanized agriculture, to developing countries. These new tools increased harvests and .
Agricultural scientist , a leader of this effort, received the Nobel Peace Prize in 1970. Borlaug made a point of agreeing with Ehrlich in his Nobel lecture, saying the Green Revolution was a temporary reprieve and that in the ongoing battle against hunger.
Conservative economists and scientists weren’t persuaded. One prominent critic, academic economist , argued for what came to be called the , which held that the only limits to growth were imagination and ingenuity. Simon said the Earth had infinite capacity to provide materials and that humans would constantly innovate and .
In 1980 Simon that prices of five important industrial raw materials — copper, nickel, tungsten, chromium and tin — would fall rather than rise over the next decade. Ehrlich said he would have preferred some environmental measure rather than metals, but he said .
Simon, on the other hand, argued that markets and new technologies would drive prices down. Ultimately, although prices for these five metals had risen during the preceding decades and would also rise during the 1990s, they . Simon won the bet, and Ehrlich for US$576.07, the difference between the 1980 and 1990 prices.
Metals prices may not have been a good proxy for the issues that Paul Ehrlich and Julian Simon sought to capture in their famous bet.
A matter of when
After the catastrophes that Ehrlich predicted in “The Population Bomb” failed to occur, many critics had a laugh at his expense. “As you may have noticed, England is still with us. So is India,” in 2015.
“Paul Ehrlich is a misanthrope who’d make you apply for a government permit to have a baby if he could,” wrote in 2023.
Ehrlich and his supporters replied that while the Green Revolution might have forestalled widespread famine, human impacts were weighing ever more heavily on the planet. Taking problems such as climate change and toxic pollution into account, Ehrlich asserted in 2009 that “The Population Bomb” had been “.”
In his 2023 memoir, “,” Ehrlich expressed deep gratitude for a 70-year career in science. However, he was frustrated over what he saw as the inability of science to penetrate America’s stubbornly unscientific political culture. He was also saddened that the environmental movement was failing to effectively oppose “the forces that pose existential threats to civilization.” Throughout his career as a public scholar, Ehrlich was never afraid to look into the abyss.
This article has been updated to correct the date of Ehrlich’s death.
, Professor of Communication,
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