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Study Reveals Exxon Accurately Predicted Global Warming Decades Ago

For the first time, researchers have quantitatively shown Exxon’s internal data on global warming was highly accurate.

A sign for an Exxon gas station stands in a Brooklyn neighborhood on October 28, 2016, in New York City.

The latest study from Harvard researchers who analyzed internal documents showing the extent to which Exxon Mobil knew about the climate crisis decades ago has found that Exxon’s climate studies were incredibly accurate in predicting the effects of global warming as early as 1977 — further confirming that Exxon knowingly perpetuated a decades-long campaign to deny the existence of the climate crisis.

While there has been research and journalistic investigations into Exxon’s knowledge of the climate crisis on a qualitative basis, the study, published in Science, analyzed the data behind 16 studies by Exxon researchers for the first time.

It finds that Exxon’s scientists predicted, on average, that burning fossil fuels was going to cause the earth to warm by 0.20 degrees Celsius per decade, with an uncertainty of 0.04 degrees. Within uncertainty, this was the same warming that was projected by other academic and government researchers of the time, and is spot on with the current observed rate of warming of 0.18 degrees Celsius per decade over 1981 levels.

Exxon’s scientists further predicted that global warming would first start to be detectable around the year 2000, which was on par with what other scientists were predicting at the time.

But executives at Exxon and other fossil fuel companies worked to suppress their own researchers’ findings and the very existence of the climate crisis for decades — and the industry continues to do so today.

“Between 1977 and 2003, Exxon’s scientists modeled and predicted global warming with shocking skill and accuracy, only for the company to spend the next couple decades denying that very climate science,” study lead author and University of Miami associate professor Geoffrey Supran, who conducted this research under his former position as a Harvard researcher, told Truthout.

In order to assess the accuracy of Exxon’s projections, Supran and fellow Harvard researcher Naomi Oreskes, as well as Potsdam University professor Stefan Rahmstorf, applied a “skill” test to Exxon’s projections compared with observed temperature changes over time.

They found that Exxon’s projections were “highly skillful,” at an average of 67 percent, with one peer-reviewed publication from 1985 having a skill score of 99 percent. By comparison, global warming projections presented by NASA scientist James Hansen in his groundbreaking testimony before Congress in 1988 had skill scores by the same metric of between 28 and 81 percent.

The study will surely give fuel to the “Exxon Knew” movement, under which advocates are waging legal battles and political pressure campaigns, with new quantitative evidence showing the extent to which Exxon knew about the climate crisis.

“Our findings demonstrate that ExxonMobil didn’t just know ‘something’ about global warming decades ago — they knew as much as academic and government scientists knew,” the authors wrote.

“But whereas those scientists worked to communicate what they knew, ExxonMobil worked to deny it — including overemphasizing uncertainties, denigrating climate models, mythologizing global cooling, feigning ignorance about the discernibility of human-caused warming, and staying silent about the possibility of stranded fossil fuel assets in a carbon-constrained world,” the authors continued.

These internal studies came at a pivotal time for the fossil fuel industry, as industry giants like Exxon were considering pursuing renewable energies instead of continuing to focus on fossil fuels — but instead doubled down on climate denial.

Fossil fuel companies are still actively choosing not to make this pivot. As a recent landmark House Oversight Committee report showed, in recent years, companies like Shell, BP, Chevron and Exxon have put out reports and done PR blitzes attempting to greenwash their public image, emphasizing their climate goals and investments in renewable energy. All the while, executives and employees have acknowledged internally that these efforts are being made to protect profits, rather than to mitigate the climate crisis.

Combined with research on the fossil fuel industry’s climate denial in previous decades, like Supran and Oreskes’s influential 2017 study analyzing Exxon’s internal efforts to deny the climate crisis between the 1970s and 2010s, the report demonstrates how the fossil fuel industry’s denial tactics have evolved over time as public opinion has shifted.

“I think it’s important to recognize that all of this history — from their research to their denialism to their delayism — is part of ExxonMobil’s coherent public affairs campaign to manage an existential threat to its business as usual,” Supran said. “Their rhetoric has inevitably had to evolve to keep up with public and political awareness, but the end goal remains the same: to delay climate action.”

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