A new study published in the scientific journal Science and based on internal documents of the oil company Exxon reveals that the company has had a fairly accurate model of the long-term effects of fossil fuels on the climate since the 1970s.
On behalf of Exxon, some researchers had predicted global warming, in measures similar to those actually found so far. In addition to having ignored those documents for decades without making them public, the company had long contested the studies on climate change defining them until 2013 “too uncertain” and fighting to avoid any limitation on the use of fossil fuels.
The new study published in Science, one of the leading scientific journals in the world, was conducted by a research team from Harvard University and the Potsdam Institute for Climate Impact Research and led by Geoffrey Supran. The latter called the conclusions of the study and some original graphs from the 1970s contained therein the “smoking gun”, i.e. the definitive proof that Exxon was aware of the long-term effects of the use of fossil fuels, starting right from the oil and coal.
Not only did Exxon “know something” over the years about the causes of global warming that it officially denied, but it had scientific models and results before independent researchers.
One of the “internal” graphs and the overlay with real data (Supran et al.)
The more than one hundred documents and researches, conducted by employees of Exxon itself or commissioned by the oil company to external researchers between 1977 and 2003, predicted an increase in the average global temperature of about 0.2 °C every ten years as an effect of of greenhouse gases attributable to the combustion of oil and coal. The analyzes debunked the theory, which had some support at the time, that the planet might be undergoing a new ice age and instead rather accurately predicted human-influenced and “carbon dioxide-induced” warming. The company’s scientists had also pointed to the early 2000s as the date when the effects would be universally recognized and “discovered” by the general public and indicated a share of fossil fuel use that would need to stay below to avoid an increase in the global average temperature above 2°C.
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The study defines the results available to Exxon in those years as more accurate and complete than those with which NASA scientists, and in particular James Hansen, warned the world of the risks years later, in 1988. It is not the first publication that highlights how large oil companies and energy companies were aware of the effects on global temperatures of burning oil and coal: the existence of internal research in this sense since the 1950s has already been demonstrated, but this study presents results more complete and detailed.
Exxon is one of the largest oil companies in the world and owns, among others, the Esso brand with which it is on the market in Italy. On Thursday he denied these conclusions, contacted by BBC News: “The question has already been presented several times and on each occasion our answer is the same: those who say that ‘Exxon knew’ are claiming incorrect conclusions”.
Exxon, as well as other large companies in the sector, for decades has rejected scientific conclusions on global warming caused by human activities, calling them now “speculative”, now “bad science” and opposing any regulation of emissions until a few years ago. The Harvard University study reveals that internally the company used the same models and was aware of the long-term effects.
