ExxonMobil scientists accurately predicted global warming back in the 1970s

The big oil and gas industries have said for years that no causal link between fossil fuel use and global warming could be established due to the uncertainty of the models used at the time. a published study Science proves that at least one of them, ExxonMobil, was, on the contrary, very clearly considering the global impact of its activities.

According to an analysis published in Science, by researchers at Harvard and the Potsdam Institute for Climate Impact Research, found that ExxonMobil’s internal projections of fossil fuel impacts on climate change from the late 1970s were highly accurate and “consistent with those provided by independent academic and government models.” Not only did they predict that anthropogenic global warming would be detected by the year 2000 (±5 years), but they also estimated the amount of CO2 that would cause dangerous warming.

It was in 2015 that investigative journalists uncovered internal company records that revealed the oil company had long known its products could have dramatic environmental impacts. But no one had looked carefully at the digital and graphic information included in these documents. In this study, Geoffrey Supran of Harvard’s Department of the History of Science and two colleagues set out to assess the validity of these predictions. ” Between 1977 and 2003, we saw Exxon’s brilliant scientists model and predict global warming with frankly shocking skill and accuracy. Supran said.

“Pretty reliable” models and analyses

Naomi Oreskes, a professor of the history of science and co-author of the study, adds that their predictions were not only extremely accurate, but also more accurate than simultaneous predictions by independent university and government scientists. ! Despite these predictions, the multinational energy giant spent the next two decades denying the facts, emphasizing uncertainties or downplaying climate models.

The study authors analyzed 32 articles produced by ExxonMobil scientists and officials between 1977 and 2002, as well as 72 peer-reviewed scientific publications authored or co-authored by ExxonMobil scientists between 1982 and 2014. models and analyzes that predict global warming due to CO2 emissions in the next few decades with great accuracy.

To test the performance of these models, Supran and his co-authors used statistical methods from the Intergovernmental Panel on Climate Change (IPCC). They found that the predictions made by Exxon scientists were 63-83% accurate. For comparison, let’s note that the forecasts presented by NASA scientist James Hansen to the US Congress in 1988 achieved results between 38-66 percent. The team calculated that Exxon’s forecast had an average “proficiency score” of 72% (±6%)—very close to reality.

Summary of global warming projections reported by ExxonMobil scientists in internal documents between 1977 and 2003 (grey lines), overlaid with historically observed temperature changes (red). Solid gray lines show predictions modeled by ExxonMobil scientists themselves; dotted lines indicate internally replicated predictions from third-party sources. Shades of gray correspond to the dates of the projections from oldest (1977: lightest) to most recent (2003: darkest). © G. Supran and others.

These models predicted that CO2 emissions would lead to an average global warming of 0.20°C per decade with a margin of error of 0.04°C – a trend that is (unfortunately) largely correct. Exxon scientists estimated that this human-caused warming could be detected in 2000, roughly five years later.

Speech aimed at placing the blame on consumers

Supran and Oreskes previously published a series of papers in 2017 analyzing 40 years of Exxon’s climate communications: they concluded that there was a “systematic discrepancy” between what Exxon was saying internally and in academia and what the company was telling the general public. public. In 2021, they also published a study of ExxonMobil’s climate change communication rhetoric, detailing how the company subtly shapes the public debate on the topic—a strategy the study authors equated with “tobacco industry propaganda.”

In this study, they note, for example, that using the term “climate risk” allows Exxon to minimize the reality and severity of climate change. Similarly, talking about consumer “demand” rather than fuel “supply” was intended to blame consumers for global warming. Exxon also said that renewable energy is unreliable.

This new study, which qualitatively assesses Exxon’s knowledge, today proves how much the general public has been deceived for years. ” We now have absolutely irrefutable evidence that Exxon accurately predicted global warming, before openly attacking climate science and scientists. Supran concludes.

Namely, oil and gas companies are now being sued by several states and cities for their “longstanding insider scientific knowledge of the causes and consequences of climate change and their campaigns to deceive the public.”

Source: G. Supran et al., Science