In the spring of 1972, a slim book called The Limits to Growth dropped like an intellectual bomb on the developed world’s most optimistic assumptions about itself. Peppered with computer-generated graphs and written in clear, dispassionate language by a team of MIT graduate students led by two young scholars, Dennis and Donella Meadows, the book delivered a seemingly extreme argument, which ran as follows: If 1970 rates of economic growth, resource use and pollution continued unchanged, then modern civilization would face environmental and economic collapse sometime in the mid-twenty-first century. Yes, collapse—as in massive human die-offs.

It was a message that many people in the industrialized world already seemed to feel intuitively. They could see it—or thought they could—in the ever-faster pace of change embodied in highways, smog, telecommunications, jet travel, tasteless frozen TV dinners, urban riots, youth rebellion, and the bloody spectacle of a high-tech military fighting low-tech guerrillas in Vietnam. For many people, the world was moving too fast and in the wrong direction, and The Limits to Growth seemed to prove that point scientifically.

The book sold 12 million copies, was translated into thirty-seven languages, and remains the top-selling environmental title ever published. In many ways, it helped launch modern environmental computer modeling and began our current globally focused environmental debate. After Limits, environmentalists, scientists and policy-makers increasingly thought of ecological problems in planetary terms and as dynamically interconnected.

It is worth revisiting Limits today because, more than any other book, it introduced the concept of anthropocentric climate change to a mass audience. And now, forty years on, we are finishing another year full of indications that the economy and nature are badly out of balance: summer Arctic sea ice shrank to its smallest-ever recorded area; heat-trapping atmospheric concentrations of carbon dioxide have reached an alarming 400 parts per million; the first seven months of the year were the warmest and driest on record in the United States; Superstorm Sandy flooded and smashed $45 billion worth of infrastructure in a swath stretching from Ohio to New York City and beyond; and drought has pushed food prices to politically dangerous heights. 

Launched with great fanfare and a massive transatlantic PR effort, Limits combined the glamour of Big Science—powerful MIT computers and support from the Smithsonian Institution—with a focus on the interconnectedness of things, which fit perfectly with the new countercultural zeitgeist. Limits was also the culmination of a steadily building environmental awareness. In the early 1950s, the Cuyahoga River had ignited. As late as 1966, a smog inundation in New York City killed several people and sickened thousands. Three years later, a massive oil spill hit the beaches of Santa Barbara. There were consciousness-raising books like Rachel Carson’s 1962 Silent Spring, and that first photograph of Earth shot from space, showing a vulnerable-looking “blue orb in a sea of blackness.” And, finally, the massive Earth Day demonstrations of 1970. Limits could hardly have arrived at a more opportune time.

Though Limits was written by the Meadowses and two others, the initial idea and funding came from the Club of Rome, an unusual, amorphously structured ad hoc group of some seventy-five experts, mostly white European male scientists, academics, civil servants and businessmen. 

Describing itself as an “invisible college,” the Club of Rome first convened in 1968, as the world erupted in protest and rebellion. Prominent members included Pierre Trudeau, the left liberal Canadian prime minister, and Dzhermen Gvishiani, then Soviet deputy chair of the State Committee for Science and Technology. The group also included a few women, among them Queen Beatrix of Holland, and some members from the global South elites, like Prince El Hassan bin Talal of the Jordanian royal family, but that was the extent of its diversity.  

The Club was also intentionally (or maybe naïvely) apolitical in its thinking. It cast environmental crisis as a primarily technical problem. Or perhaps it is better described as crypto-Fabian: pro-planning in outcome, but elitist in method.

At the intellectual and financial center of the Club was Aurelio Peccei, a charismatic, eccentric, workaholic Italian industrialist who had been briefly jailed in 1944 by Mussolini’s security services for helping the anti-Fascist resistance. It was at a dinner in Peccei’s Rome apartment that the eponymous Club of Rome was formed; its mission, in the words of Peccei, was to “rebel against the suicidal ignorance of the human condition.” The Club sought to better understand the links between economics and the environment, or what they called “the World Problematique.”

Toward this end, the Club—or mostly Peccei—convinced the Volkswagen Foundation to fund a major study based on the methods of MIT professor Jay Forrester, the father of “system dynamics.” This was a new, computer-aided approach to the analysis of complex systems, be they social, mechanical, managerial, economic or ecological. Forrester and his students sought to scientifically and mathematically crack the genetic code of all systems. As a theory, system dynamics was all form and no content, and thus was inherently depoliticizing. 

System dynamics theorists viewed systems as either open or closed. In an open system, the outputs—like paper through a printer—do not affect the original inputs. But in a closed system—such as the Earth’s biosphere—all outputs potentially act back upon the inputs in what is referred to as “feedback loops.” In The Limits to Growth, the Earth’s social and natural systems were mathematically modeled as a closed system with numerous feedback loops between cause and effect. 

Forrester asked Dennis Meadows to assemble a team of sixteen researchers to collect the relevant data, build a computer model, and crunch the numbers. Donella Meadows, Dennis’s wife and fellow scientist, did most of the actual book writing. The MIT team members examined the interaction of five related factors: population, food production, industrial production, consumption of nonrenewable resources and pollution. They plugged the best available data into their model and ran numerous scenarios based on different sets of assumptions. None painted a terribly optimistic picture of the future.  

Limits’ argument hinged on the idea of exponential growth, which occurs when something increases by a constant percentage of an ever-expanding whole. This means the more a thing grows, the faster its rate of growth in absolute terms will be. From this followed the idea that by the time humanity would feel the impact of the environmental crisis, the problem could be accelerating so fast that it might be impossible to stop. Thus, a cataclysmic “overshoot” of the Earth’s natural physical limits was a very real possibility. 

But, Limits had its critics within mainstream journalism and academia. Foreign Affairs ran a review called “The Computer That Printed Out W*O*L*F*.” Three economists writing in The New York Times Book Review dismissed Limits as “an empty and misleading work…. Less than pseudoscience and little more than polemical fiction…. Garbage In, Garbage Out.” A Newsweek editorial called it “a piece of irresponsible nonsense.” 

Another Newsweek article quoted a different set of prominent economists—Robert Solow (later awarded the Nobel Memorial Prize in economics), Allen Kneese and Ronald Ridker—attacking the book. The latter two charged: “The authors load their case by letting some things grow exponentially and others not. Population, capital and pollution grow exponentially in all models, but technologies for expanding resources and controlling pollution are permitted to grow, if at all, only in discrete increments.” These were intellectually dishonest attacks; contrary to the claims by Solow et al., the book contained several scenarios that allowed for exactly what the economists claimed it did not, which is to say: unlimited resources, technology, pollution controls and agricultural production. Of the twelve scenarios in the book, seven ended in collapse, one in a sort of half-collapse and the rest in equilibrium. Admittedly, the most seemingly realistic scenarios had the worst outcomes. As the authors explained, without “major change in the present system, population and industrial growth will certainly stop within the next century.” 

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Over the decades, Limits was updated, rewritten and republished two more times; each time, the attacks were renewed. In this fortieth anniversary year, Foreign Affairs even deployed the discredited anti-green critic Bjørn Lomborg to bash and mock Limits. Never mind that the unscrupulous, media-loving Dane’s own work has been systematically dismantled, footnote by footnote, in Howard Friel’s The Lomborg Deception. 

Lomborg and others have accused Limits of hysteria. The book is not hysterical. It was, however, taken up by a social milieu heavily populated by hysterics like the peak oilers and the (sometimes crypto-racist) population bugs. Paul Ehrlich embodies this most clearly: for almost fifty years, he’s been pushing a simple-minded Malthusian condemnation of population growth. In the late 1960s, with world population at 3.5 billion, Ehrlich said in a TV interview: “Sometime in the next fifteen years, the end will come. And by ‘the end’ I mean an utter breakdown of the capacity of the planet to support humanity.” Limits, meanwhile, never made such an outlandish claim. 

If we can boil down Limits’ arguments to two key issues, they would be resource depletion and pollution. With forty years’ hindsight, we could say that the authors’ view of nonrenewable resource scarcity has been a bit overstated. We’ve been using resources at about or exactly the rate the book’s business-as-usual or “standard run” scenarios projected. But, we keep finding more oil and more minerals or inventing new substitutes. 

As the economists say, demand calls forth supply. Just look at all the new shale gas. The United States has gone from having a twenty-year supply of known reserves to a 100-year supply, thanks to the new technology of hydraulic fracturing used to get at both gas and oil. Whatever one wants to say against the practice of fracking (and, for the record, I believe it is dangerous and so I’m against it), it has opened up huge new fossil fuel reserves and thus pushed the notion of “peak oil” further into the future. (The real problem is not too little oil, but too much oil and the pollution it causes.) In other words, technology and innovation continue to transcend the limits of supply. 

But on the second issue—the limits of natural “sinks,” or the Earth’s ability to absorb pollution—the catastrophically bleak vision of Limits is playing out as totally correct. We may find new inputs—more oil or chromium—or invent substitutes, but we have not produced or discovered more natural sinks. The Earth’s capacity to absorb the filthy byproducts of global capitalism’s voracious metabolism is maxing out. That warning has always been the most powerful part of The Limits to Growth.

Most worryingly, we have overloaded the atmosphere with heat-trapping CO2 and, in recent years, discovered that the sea has also absorbed vastly more carbon dioxide than was thought. As a result, the ocean’s average pH level is about 30 percent more acidic than it was 100 years ago. This is threatening the formation of calcium carbonate exoskeletons in shellfish, including the very tiny ones at the base of the marine food chain. In other words, lots of the fish we eat, like salmon, rely for food on these acidity-threatened little creatures.

Parts of the left, though generally embracing Limits, also had serious problems with it. One critique focused on Limits’ simplistic view of population. Progressive demographers have long argued that concerns about overpopulation ignore the real issue: the unequal distribution of consumption. Environmentally speaking, the threat of pollution is not driven by the total number of people so much as by the number of rich and wasteful people. Put another way: How many impoverished villages in Afghanistan, full of unlit homes and barefoot children, would it take to equal the ecological footprint of one rich family? If that rich family splits its time between a Manhattan brownstone and a Southampton mansion, drives multiple large vehicles, flies frequently, and feeds its pets ample amounts of animal protein and medicine every day, then the unscientific answer would be that several—maybe even scores of—Afghan villages still can’t match the environmental footprint of one rich family. 

When I reached Dennis Meadows by phone recently, he readily conceded as much: “You could have 10 billion people living on the planet at a subsistence level and be fine. Or 500,000 people on the planet living a first world lifestyle. It is not the absolute number of people, but the multiple of the high-consumption lifestyle.”  

Another left critique has been that Limits, and for that matter much of the US environmental movement, has no critical understanding of class power in capitalist societies, or any theory of the state. In Limits, the culprit is growth itself. But why do capitalist economies need to grow? Because competition and the quest for profit compel each business to grow or be wiped out by its competitors. Only public regulation can control that. 

Alas, taboo questions of political economy—for example, what can and should government do to discipline private capital?—were largely avoided in all three versions of The Limits to Growth. Johan Galtung, the Norwegian father of peace studies, took this line of attack back in 1984 when he wrote: “The book gives its message in what looks like a ‘non-political’ form: at no point are political constants and variables introduced. It presents the world, with rich countries and poor countries, with oppressors and oppressed, with all of us, as if this were an ecological system with some animal and some non-animal components, a thermodynamic system….” In reality, the world human community is a social system, regulated by power, ideas and violence. But Limits mostly failed to address that.

When I asked Meadows about this, he again very graciously conceded the point. “It was outside the scope of our work,” he said. “We didn’t talk about the political and economic aspects of the problem because politics—states—are too diverse. Lumping all states into a single variable is not plausible.” 

Perhaps it is too much to expect any one book to do everything a reader might wish. And thus the other questions are for other books. Or, perhaps, Limits’ failure to interrogate the problem of socioeconomic power—its failure even to flirt covertly with critical and radical theories of social change—may also explain why, despite its popularity and commercial success, it didn’t have a greater impact on real policy. 

This question of power leads back to the original sin of the funders: the remarkable naïveté of Aurelio Peccei, the Club of Rome and the de-historicizing, mechanistic worldview of Jay Forrester’s systems dynamics. If power concedes nothing without a demand, then Limits didn’t even try. 

That said, The Limits to Growth was a scientifically rigorous and credible warning that was actively rejected by the intellectual watchdogs of powerful economic interests. A similar story is playing out now around climate science.

Donella Meadows, who died tragically in 2001 from a sudden and fast-moving bacterial infection, maintained her political optimism. These days, Dennis Meadows takes a darker view: “In the early 1970s, it was possible to believe that maybe we could make the necessary changes. But now it is too late. We are entering a period of many decades of uncontrolled climatic disruption and extremely difficult decline.” 

Meadows suggests that we focus on adaptation: trying to build resilience into the system so as to cope with the coming upheavals and still maintain our commitment to democracy and equity. Forty years ago, he got it far more right than wrong. It might be worth listening closely to and thinking hard about his new message.

“We should not have called it Hurricane Sandy. We should have called it Hurricane Exxon,” says climate activist Bill McKibben (video). But author Christian Parenti, in a conversation with NYU student Becky Nathanson, explains why fossil-fuel divestment campaigns—now gaining popularity on college campuses thanks to Bill McKibben—may be a costly distraction.