ExxonMobil predicted climate change as early as 1970s yet publicly denied it, study finds

ExxonMobil scientists had accurately predicted global warming due to human-induced emissions since the 1970s even as the oil giant lobbied and launched campaigns to delay climate action, according to a new study.

For decades, several fossil fuel companies have tried to convince people that a causal link between fossil fuel use and global warming cannot be made, arguing that the climate models used to project Earth’s temperature changes are uncertain.

The new research, published in the journal Science on Friday, conducted the first ever systematic assessment of the fossil fuel industry’s internal climate projections.

Scientists, including those from Harvard University and the Potsdam Institute for Climate Impact Research, assessed the accuracy of global warming projections reported by Exxon and ExxonMobil Corp scientists between 1977 and 2003, based on never-before reported data buried in the Oil Giant’s internal documents.

Researchers found that most of the company’s projections accurately forecast warming consistent with subsequent observations and their predictions were also “consistent” with, “and at least as skillful as”, those of independent academic and government models.

The findings suggest that what oil companies understood about climate models internally contradicted what they led the public to believe.

“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,” researchers wrote in the study.

ExxonMobil, the study reports, worked to deny the findings of its own scientists, by following strategies like denigrating climate models, overemphasising uncertainties in the analyses, mythologising global cooling, and claiming ignorance about the possibility of estimating human-caused warming.

About 60 to 80 per cent of global warming projections reported by ExxonMobil scientists were consistent with subsequently observed temperatures, according to the study.

But in 2004, for instance, the company said “scientific uncertainties continue to limit our ability to make objective, quantitative determinations regarding the human role in recent climate change”, contrary to the findings of its own scientists.

“Exxon and ExxonMobil Corp also correctly rejected the prospect of a coming ice age, accurately predicted when human-caused global warming would first be detected, and reasonably estimated the ‘carbon budget’ for holding warming below 2°C,” scientists wrote in the study.

However, on each of these points the company’s own public statements about climate science “contradicted its own scientific data,” researchers say.

“These findings corroborate and add quantitative precision to assertions by scholars, journalists, lawyers, politicians, and others that ExxonMobil accurately foresaw the threat of human-caused global warming, both prior and parallel to orchestrating lobbying and propaganda campaigns to delay climate action,” they added.

The latest report also refutes claims by the oil giant and its defenders that these assertions are incorrect.

“Our analysis shows that ExxonMobil’s own data contradicted its public statements, which included exaggerating uncertainties, criticizing climate models, mythologising global cooling, and feigning ignorance about when – or if – human-caused global warming would be measurable, all while staying silent on the threat of stranded fossil fuel assets,” study lead author Geoffrey Supran said.

“This is the nail-in-the-coffin of ExxonMobil’s claims that it has been falsely accused of climate malfeasance,” he added.

“This issue has come up several times in recent years and, in each case, our answer is the same: those who talk about how ‘Exxon Knew’ are wrong in their conclusions,” the company told BBC.

The Independent has reached out to ExxonMobil for a comment.