The Exxon Climate Research Files: What Company Scientists Knew in the 1970s

In July 1977, a senior scientist at Exxon named James Black stood before the company’s Management Committee and told the most powerful people in one of the largest corporations on earth that burning fossil fuels was going to warm the planet. A year later he sharpened it in a written summary: mankind, he wrote, had a window of perhaps five to ten years before the need for hard decisions about energy strategy became critical. This was not a fringe warning from an outside activist. It was Exxon’s own research arm, addressing Exxon’s own executives, in language calm enough to survive a boardroom. Over the following years the company would put real money and serious scientists behind understanding the problem — fitting sensors to one of its supertankers, the Esso Atlantic, to measure how the oceans absorbed carbon dioxide, and building climate models whose projections, we can now check, were remarkably close to what actually happened. And then, having understood the danger better than almost anyone alive, the company spent the next quarter-century helping the public believe the danger was unproven.

The physics the company paid for

The heart of this story is a set of documents that were never meant to be read side by side with Exxon’s later public statements. When investigative journalists at InsideClimate News and, separately, the Los Angeles Times obtained and published them in 2015, the gap between the two records was so wide that it launched investigations by several US state attorneys general.

The internal science was genuinely good. Exxon employed capable atmospheric researchers, chief among them Henry Shaw, and it collaborated with academic institutions. Its scientists did not merely acknowledge the greenhouse effect as a theoretical possibility; they quantified it. In 1982, a comprehensive internal briefing document circulated to Exxon management projected that atmospheric carbon dioxide would roughly double from pre-industrial levels around the middle of the twenty-first century, and that this would raise global average temperatures by something in the region of two degrees Celsius, with larger increases toward the poles. The document warned that the effects “could be catastrophic for a substantial fraction of the world’s population.”

The oceanographic work is worth dwelling on, because it shows a company doing serious, expensive science rather than idle theorising. Between 1979 and 1982, Exxon fitted its supertanker Esso Atlantic with equipment to sample carbon dioxide in seawater and the air above it on Atlantic crossings, trying to pin down how much of humanity’s emitted carbon the oceans would soak up — a genuinely open scientific question at the time, and a crucial one, because the answer determines how fast the atmosphere warms. The company also ran a rising-CO2 research programme under Henry Shaw and collaborated with academic scientists, including at Columbia University’s Lamont-Doherty laboratory. This was not a firm dabbling to reassure itself. It was investing in first-rate climate research because it wanted, for hard commercial planning reasons, to know the truth. Having found it, it made a choice about what to do with it.

In 2023, a team of researchers led by Geoffrey Supran and Naomi Oreskes published a study in the journal Science that did something quietly devastating: it took the actual numerical projections Exxon’s scientists had made between 1977 and 2003 and graded them against the real-world temperature record. The company’s in-house models had been accurate. Their projected rate of warming — roughly 0.2 degrees Celsius per decade — matched what subsequently occurred, and was consistent with the independent projections of academic and government scientists at the time. Exxon knew, with the precision of a company that had done the arithmetic properly, what its product was doing to the atmosphere. There is no serious argument about this anymore, because the numbers are in the company’s own files.

The turn toward doubt

What makes the Exxon papers a story about human nature rather than only about physics is the pivot — the moment a company that understood the problem chose to spend its resources obscuring it. The fork does not come where the science departs from reality. The science was right. The fork comes where the public message departs from the private knowledge.

Through the 1980s the internal research programme was scaled back, and by the end of the decade the company’s public posture had reorganised itself around a single strategic goal: to prevent or delay any binding limits on carbon emissions. In 1989, oil, coal, car and utility companies formed the Global Climate Coalition, and Exxon was a leading member. The Coalition’s purpose was to fight the emerging international consensus, and it did so with a strategy that will feel familiar to anyone who has read the Tobacco Institute papers: to stop short of outright denial and insist instead that the science was too uncertain to act on.

The parallel was not accidental. The historians who traced Big Tobacco’s playbook of manufactured doubt found the same public-relations firms, the same think tanks, and in some cases the same individual scientists-for-hire moving from the cigarette fight to the climate fight, carrying the method with them. The message was engineered to sound reasonable. No one from Exxon needed to stand up and say global warming was a hoax. They needed only to fund a steady drumbeat of “the models are unreliable,” “the climate has always changed,” “we need more research before we wreck the economy” — every honest scientific caveat inflated into a reason to do nothing. Through the 1990s and 2000s, Exxon (from 1999, ExxonMobil) channelled tens of millions of dollars to a network of think tanks and advocacy groups that questioned climate science, a funding trail later documented by the Union of Concerned Scientists and by the company’s own disclosures.

The most exquisite artefacts of the period are the “advertorials” — paid opinion pieces the company ran for years on the op-ed page of the New York Times. They were written in the measured, sceptical register of a responsible corporation urging prudence. One from 2000 was titled, without apparent irony, “Unsettled Science.” The company’s own scientists had settled the essentials two decades earlier.

What the delay was worth

To understand why a company would knowingly obscure a danger it had itself measured, follow the same logic that ran through the tobacco files. The prize was never winning the scientific argument, which was unwinnable. The prize was time.

Every year that binding emissions limits were delayed was another year of selling the product at full volume, without the cost of transition. For a fossil-fuel company in the 1990s, the entire business rested on the assumption that its reserves — the oil and gas still in the ground, valued on its balance sheet — would be extracted and sold. Serious climate action threatened to turn some of those reserves into “stranded assets,” worthless in the ground. Doubt was the instrument that protected the balance sheet. It did not have to persuade forever. It only had to hold the political line for one more budget cycle, one more election, one more decade of extraction, and it did that job for a very long time.

The cost of the delay is the part that is hard to hold in the mind, because it is measured in a future that is still arriving. The years around 1990 — when Black’s five-to-ten-year window had long since closed — were plausibly the last moment when a gradual, managed energy transition might have been possible at manageable cost. The doubt campaign helped ensure that moment passed without action. This is the real weight of the Exxon files, and why simply establishing that the company “knew” understates the matter. Knowing is not a crime. Spending money to make sure the public didn’t know, while the window closed, is a decision with a body count that will be counted for centuries.

The believers on both sides of the knowing

Here the story complicates in a way worth sitting with, because the Exxon papers created two very different communities of believers, and both are shaped by the same underlying betrayal.

For the climate movement, “Exxon knew” became a rallying cry precisely because it converts a diffuse, planetary, statistical threat into a legible human story with a villain, a document, and a date. That is enormously useful, and largely accurate. But it can also tip into a comforting oversimplification — the idea that a single wicked corporation duped an innocent public, when in truth the demand for cheap petrol was universal, the addiction to fossil energy ran through every household, and no amount of corporate honesty in 1980 would have made people volunteer to pay more at the pump. Exxon’s cover-up is real and grave. It is also not the whole reason the world kept burning oil. We all wanted the oil.

And for the sceptical public, the revelation cuts the other way and lands somewhere painful. Once you learn that an oil major secretly held accurate climate science while publicly funding doubt about it, a certain kind of trust dies — in oil companies and in the whole apparatus of official reassurance alike. It becomes rational, even, to assume that powerful institutions are lying about mortal dangers, because here is a documented case where one was. The tragedy is that this well-earned suspicion does not stay aimed at the guilty party. It metastasises into a general distrust that the fossil-fuel industry itself learned to exploit, seeding the idea that all climate science is just another interested party’s spin. The doubt they manufactured about their product ended up corroding the public’s ability to believe anything, which turned out to serve them perfectly.

Why we needed the villain to be simple

Strip the Exxon story to its core and it is about the unbearable difficulty of a threat that is real, slow, invisible, and everyone’s fault at once. Carbon dioxide is odourless. The harm is decades deferred and globally smeared. No single act of driving to work or heating a house feels causal. A human mind built to detect a predator in the grass finds almost nothing to grip.

The corporate cover-up gives that formless dread a shape. It offers a document, a date, a boardroom, a lie — the reassuring architecture of a proper crime, with someone to be angry at. And because the crime is real, the anger is justified. But the deeper thing the Exxon files reveal is not simply that a company lied. It is that we needed a liar in order to make the problem feel like the kind of thing a human being can be angry about at all. The atmosphere does not respond to indictment. The oil that James Black warned about in 1977 is, most of it, already burned, sold to willing buyers who mostly did not want to know either. The value of the documents is not that they let us convict a corporation. It is that they show, in a company’s own careful handwriting, exactly how a society talks itself out of knowing something it cannot bear to act on — and how profitable it can be to help it along.