The accusation is not new: Decades ago, Exxon-Mobil researchers are said to have pointed out the dangers of climate change internally, only to see how their company publicly downplayed precisely these in-house findings.
That is exactly the message of a new study, but it has a special impact.
According to its authors, it underscores for the first time with company-internal figures how good Exxon researchers were and how accurately they predicted climate change.
Exxon is unimpressed and counters that the new study, like the previous allegations, ignores the facts.
That won't convince environmental activists.
For them, the company is the enemy par excellence in the oil industry, and it has also contributed to it.
For example, when his CEO made fun of competitors' climate targets or when one of his lobbyists described his climate initiatives as a show and a recording of it was made public.
The new study fits the picture that critics have of Exxon.