As far back as the 1980s, oil giant ExxonMobil had remarkably accurate global warming predictions made by its own scientists that turned out to be precisely what happened decades later, a researcher has confirmed. new study published Thursday.
Despite this, the company has for years publicly cast doubt on the state of scientific knowledge on the subject, underlined this study published in the prestigious journal Science.
ExxonMobil, one of the world’s biggest oil companies, “modeled and predicted global warming with uncanny accuracy, only to end up spending decades denying that same climate science,” Geoffrey told AFP. Supran, co-author of this work.
For several years now, ExxonMobil has been accused of having held a double discourse on climate change, caused by the immense quantities of greenhouse gases released by humanity into the atmosphere, in particular through the combustion of coal or oil. to produce energy. Several legal proceedings have even been launched against the company in the United States, some of which are still ongoing. Hearings were held in the European Parliament and the US Congress.
But this is the first time that the projections made by the group’s scientists have been systematically analyzed and compared with those of other researchers at the time, as well as with the warming actually observed subsequently.
The starting point are documents — public archives and scientific publications — revealed in 2015 by journalists fromInside Climate News and Los Angeles Times, showing that the company had long known that climate change was real and caused by human activities. A first scientific study, carried out in 2017 by the same researchers as that published Thursday, had extended this journalistic investigation by precisely analyzing the language used by the company first in these documents, then publicly. “But even though in the past we had focused on the language and the rhetoric contained in these documents, suddenly we realized that there was […] all these charts and tables that no one had ever looked into,” explained Geoffrey Supran.
“We were excellent scientists”
“This question has surfaced several times in recent years,” a spokesperson for the company told AFP. “Each time, our answer is the same: those who evoke what “Exxon knew” are wrong in their conclusions. »
However, ExxonMobil has never denied the authenticity of the documents in question.
In total, the researchers analyzed 32 internal documents produced by ExxonMobil scientists between 1977 and 2002, and 72 scientific publications they co-authored between 1982 and 2014. These documents contain 16 temperature projections. “Ten of them are consistent with the observations” made subsequently, notes the study. Of the other six, two predicted even greater warming. On average, they predicted a warming of about 0.2°C per decade, which indeed corresponds to the current rate. And the predictions made by other researchers at the time were more or less similar.
ExxonMobil “didn’t just vaguely know anything about climate change decades ago,” said Geoffrey Supran, a professor currently at the University of Miami, but who conducted this work at Harvard. “They knew as much as independent and government scientists, and presumably enough to take action and alert the public. »
However, the leaders of the group have done just the opposite, insists the study, which quotes the words of the former CEO of ExxonMobil, Lee Raymond, in 2000: “We do not have a sufficient scientific understanding of the climate change to make reasonable predictions. »
In 2013, then-CEO Rex Tillerson said there were “uncertainties” around “the main drivers of climate change”.
Some of the researchers employed by the company have testified before the US Congress. One of them, Martin Hoffert, questioned in 2019 by the elected Democrat Alexandria Ocasio-Cortez who underlined how accurate his predictions had turned out, had then simply replied: “We were excellent scientists. »
On Thursday, the World Meteorological Organization confirmed that the past eight years have been the hottest on record.
During a press conference on these annual temperature reports (during which the study was not mentioned), Gavin Schmidt, a climatologist at NASA, had estimated that “exposing and shaming” to individual companies ” did not help much” to find adequate solutions to do without fossil fuels. “It’s not like we can say, ‘ExxonMobil, stop producing fossil fuels,’ and have solved the problem,” he said. “All these products are used by people. »