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ExxonMobil knew about global warming, but withheld information

It is known that "Exxon Mobil knew" half a century ago about the threats of global warming (there are even various initiatives 

By Wahid Bhat
New Update
ExxonMobil knew about global warming, but withheld information

It is known that "ExxonMobil knew" half a century ago about the threats of global warming (there are even various initiatives to denounce and investigate it). Still, now researchers from Harvard University (USA) and the Potsdam Institute for Climate Impact Research (Germany) put numbers to that statement. 

ExxonMobil knew about global warming

In the first systematic evaluation of the fossil fuel industry's climate projections, they confirm what ExxonMobil – one of the world's largest oil and gas companies – had known about climate science since the 1970s: that burning of fossil fuels would cause global warming of about 0.20°C per decade.

The conclusions, published in the journal Science and summarized in the following graph with all the global warming projections communicated by researchers from the US oil company between 1977 and 2003, are based on a statistical analysis of data never before revealed and hidden in the documents of the company, as well as in scientific articles from that time and later years.

Historically observed temperature change (red) and atmospheric carbon dioxide concentration (blue) over time, compared against global warming projections reported by ExxonMobil scientists.

By diving into Exxon's data, the study reveals that the company knew the warming was coming with astonishing accuracy. “Most of their forecasts were consistent with observations made later,” the paper states, “and their projections were also consistent with, or at least as accurate as, those of independent academic and government models,” despite the efforts of the oil company to sow uncertainty and doubt.

Human-caused global warming

Using statistical techniques established by the Intergovernmental Panel on Climate Change (IPCC), the study concludes that between 63% and 83% of global warming projections reported by ExxonMobil scientists match later observed temperatures. Furthermore, they had an average “skill score” of 72%.

By comparison, the warming forecasts of James Hansen, the NASA scientist who presented them to the US Congress in 1988, had scores ranging from 38% to 66%.

The study concludes that ExxonMobil "also correctly rejected the prospect of a coming ice age, accurately predicted when human-caused global warming would be first detected, and reasonably estimated the 'carbon budget' for keeping warming below 2°C". However, on each of these points, "the company's public statements on climate science contradicted its own scientific data."

Exxon lied?

"As historians of science, we don't use the word 'lie' lightly, because it implies intent, which is hard to prove, and suggests that the company never accurately represented reality, which is not exactly the case", explained SINC the main author, Geoffrey Supran, associate professor at Harvard University and that, starting this year, he will be at the University of Miami.

“What is true is that the company was 'misleading' the public and policymakers about climate science and its implications,” he stresses. On this point, we are very explicit in our conclusions: the company accurately, skillfully and discreetly contributed to climate science, while casting doubt on that science."

Comparison of (red) historical temperature observations and (gray or black) global warming projections reported by Exxon Mobil scientists in internal documents and peer-reviewed publications.

Although the professor clarifies that this does not mean that ExxonMobil and other oil and gas companies have not lied explicitly on different occasions about climate change: “They have. As Naomi Oreskes and I reported in the Boston Globe, the CEOs lied under oath to the US Congress about their record of public communications on climate change."

The nail in the coffin of claims of the oil company

The authors note that their findings “corroborate and add quantitative precision to the claims by academics, journalists, lawyers, politicians, and others that ExxonMobil accurately anticipated the threat of human-caused global warming, both before and in parallel with the orchestration of bells. "of lobbying and propaganda to delay climate action, and to refute claims by Exxon and its supporters that those claims were incorrect."

“This is the nail in the coffin for ExxonMobil's claims that they were falsely accused of climate malpractice,” says Supran, “our analysis shows that their own data contradicted their public statements, which included exaggerated uncertainties, criticism of climate models, mythologizing global cooling, and feigning ignorance about when, or if, human-caused global warming would be measurable, all while remaining silent about the threat from fossil fuel assets.”

The professor explains to SINC that they have not communicated their results to ExxonMobil because "it is not an academic practice to request their comments, as happens in journalism" and reiterates that this work can help to inform the "growing number of initiatives -among them litigious, political investigations and grassroots activism, demanding that the oil and gas industry be held accountable for its record of deceit and climate damage.”


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