On the 40th anniversary of the first world climate conference in 1979, the journal Bioscience published the ominously titled “World Scientists’ Warning of a Climate Emergency.” “Scientists,” the Warning begins, “have a moral obligation to clearly warn humanity of any catastrophic threat and to ‘tell it like it is.’ On the basis of this obligation…we declare, with more than 11,000 scientist signatories from around the world, clearly and unequivocally that planet Earth is facing a climate emergency.” Addressing this emergency, the Warning continued, will require a stunning prescription: “the world population must be stabilized—and, ideally, gradually reduced.”

The Warning itself might have gone the way of most academic editorializing, but the 11,000 “scientists” who added their names and reputations to the effort caught the public imagination. The press picked it up and everyone was off to the races. Right until people started looking at the credentials of the more than 11,000 signatories.

The list includes shockingly few climate scientists. It does include people who describe themselves as “PHD Student,” “MD,” and “Zoo keeper,” though. And those were drawn just from people with last names beginning with A. Critics had a field day with this, but they had more fun with signatories Mickey Mouse and Albus Dumbledore, who also signed on.

That 11,000 academics of any description would sign off this sort of thing is what’s most telling, and most damning. What do the 11,000 suggest? Quickly implementing “massive energy efficiency and conservation practices,” “eating mostly plant-based foods,” creating a “carbon-free economy,”and “reducing population,” among other things, all with the goal of bringing about “major transformations in the way our global society functions.”

Is that all? 

Their set of recommendations follows almost perfectly from a strange obsession economists have had for over two centuries, which holds the threat of “overpopulation” imperils humanity’s very existence. In past variants, this threat entailed resource depletion that would supposedly condemn most of the world to misery and starvation. 

Today’s scientists have adapted identical reasoning to climate change. In each instance, scholars claiming the mantle of scientific expertise have enlisted apocalyptic fears of a coming “population crisis” to advance sweeping programs of social engineering as a way to alter the course. But curiously, the predicted population catastrophe never comes. We are simply expected to believe that, for some reason, this time things are different even if the prescription is the same.

The root of this idea traces to eighteenth-century economist Thomas Malthus, who began with a simple, intuitively plausible observation: the population of human beings expands at a faster rate than food production increases, ensuring that the typical person’s quality of life ultimately decreases to the point of misery as a result. He was so persuasive on this count that the process became known as the “Malthusian catastrophe.”

While Malthus’s religiosity constrained him from taking this intuition to its full prescriptive end, his followers in the nineteenth and twentieth centuries attempted to mechanize a “scientific” solution by enlisting the powers of the state to socially plan and control population rates. 

Before his name became synonymous with his macroeconomic diagnosis of the Great Depression, the British economist John Maynard Keynes attained fame as one of the world’s most prominent neo-Malthusians. “There is no more important object of deliberate state policy,” Keynes wrote in 1924, “than to secure a balanced budget of population.” Indeed, Keynes prescribed population control as a “solution” to the underlying political causes of World War I, to the Soviet Union’s food and political crises, and even to the economic malaise of interwar Germany.

In a heretofore unpublished speech given before the Malthusian League in London in 1927, Keynes contended that a proper population policy must not only achieve population stability but continue to maintain and cultivate a population of a certain character after the growth pattern had been reversed. At first he spoke of birth control, but almost seamlessly slipped into the pseudoscience of hereditary social planning known as Eugenics.

“Within our own lifetime,” Keynes predicted, “the population of [Great Britain] will cease to increase and will probably diminish.” Following Malthusian logic to its end, Keynes thought this both good and necessary, even if the nations of the earth “are now faced with a greater problem, which will take centuries to solve.” The solution? Keynes concluded, “I believe that for the future the problem of population will emerge in the much greater problem of heredity and Eugenics.” As a scribbled line on his notes further acknowledged, “Quality must become the preoccupation.”

What we needed to address the Malthusian catastrophe, according to Keynes, was a smaller and “better” population, cultivated by “the powerful weapon of the preventive check” and administered through a state-directed population policy. This is the ugly intellectual heritage – and hubris – behind today’s population planners in the climate activist movement.

Because this time, they tell us, it’s different. But it would have to be, because when Malthus penned his original prediction more than 95 percent of the world’s population of one billion lived in extreme poverty. That population has grown more than seven fold, but only about one third of it lives in extreme poverty today. The Malthusian catastrophe never came. Instead, we got growing wealth and comfort on a global scale, a process that continues unabated.

Yet according to the 11,000 signatories, a new Malthusian tipping point is approaching. This time the cause is not impoverishing resource depletion itself, but the belief that too many people are enjoying the fruits of prosperity. Electricity, affordable and accessible transportation, and even the consumption of meat are recast from signs of unprecedented global prosperity and into “strains” on the climate. The sky is falling now, and once again governments must turn to seldom-elaborated forms of social engineering aimed at reducing the global birth rate.

And here is where the pedigree of the 11,000 matters. They urge us to uproot nearly the entirety of human life using an argument that has never, in over 200 years, been correct. And they are absolutely unqualified as a group to do so. The ever present danger is that politicians will take cover behind them and their bad ideas, which is not at all a far-fetched concern. 

Presidential candidate Bernie Sanders, in a recent town hall meeting on climate change, went right back to the same Mathusian well. In response to a question on global overpopulation he said that women “in the United States…have a right to control their own bodies and make reproductive decisions. The Mexico City agreement, which denies American aid to those organizations around the world that allow women to have abortions or even get involved in birth control, to me is totally absurd.” Such measures, he continued, were needed “especially in poor countries.”

A candidate for the presidency of the United States thinks it is absurd that the American people should be cautious in inflicting schemes of population control on impoverished nations. What he means but will not say is that he thinks Keynes was right. He thinks that we, in the developed West, need to decide how many and what kind of people should be born in less developed countries.

Because the environment. Because this time it’s different.