Climate researchers from Harvard University and the Potsdam Institute for Climate Research (PIK) make serious allegations against the oil company ExxonMobil.

The US company has been accurately predicting global warming as a result of greenhouse gas emissions since the late 1970s, the researchers write in an article in the journal Science.

At the same time, the company has systematically downplayed this connection for decades.

Exxon's long-standing awareness of the threat of global warming was already well known.

The climate researchers now evaluated the company's internal data and the forecasts based on it from 1977 to 2003 - they called the result "amazing".

Predictions are significantly better than those of NASA

The Exxon experts were apparently well ahead of climate research: "We find that most of their projections predict warming consistent with later observations," the report says.

"Their predictions were also consistent with, and at least as good as, those of independent academic and government models."

The forecasts were therefore significantly better than those presented by NASA scientist James Hansen to the US Congress in 1988.

Hansen is considered a pioneer of modern climate research and was one of the first to warn of the dangers of global warming in the 1980s.

"Even as early as 1977, an Exxon projection correctly predicted that fossil fuel use would cause a 'carbon dioxide-induced superinterglacial'," explained Stefan Rahmstorf of PIK, co-author of the study.

"This is an interglacial period that is not only much warmer than anything in the history of human civilization, but even warmer than the last interglacial period of 125,000 years ago."

Exaggerated insecurities

Exxon's analyzes also "precisely predicted when human-caused global warming would first appear in measured data."

They even calculated quite precisely a "carbon budget" for limiting global warming to two degrees.

However, the researchers criticize that the company has systematically contradicted “its own scientific data” in public statements.

ExxonMobil exaggerated uncertainties, criticized climate models, propagated the myth of global cooling and feigned ignorance about when -- or if -- human-caused global warming would be measurable," said study lead author Geoffrey Supran of Harvard University.

Today, climate change has progressed so far that researchers see the earth clearly on the way to the aforementioned record interglacial period - with all its catastrophic consequences.

ExxonMobil can therefore rightly be accused of "deliberate climate crimes," Supran concluded.