A 1980 report, “Review of Environmental Protection Activities for 1978-1979,” produced by Imperial Oil, Exxon’s Canadian subsidiary, again suggests that Exxon knew that CO2 was a harmful pollutant in the atmosphere in the 1970s.

Lines in the document include: “It is assumed that the major contributors of CO2 are the burning of fossil fuels… There is no doubt that increases in fossil fuel usage and decreases of forest cover are aggravating the potential problem of increased CO2 in the atmosphere. Technology exists to remove CO2 from stack gases but removal of only 50% of the CO2 would double the cost of power generation.”

The distribution list for the Imperial Oil report indicates that it was disseminated to managers across Exxon’s international corporate offices, including in Europe.