The U.S. oil and gas industry was working as early as the 1940s to spin the narrative on the role fossil fuels influenced the climate, a report finds.

A series of documents reviewed by the Center for International Environmental Law suggests the oil and gas industry in the United States was examining the link between the burning of fossil fuels and harmful pollution as early as 1919. By the 1940s, the study suggests, a committee of executives from companies that later became Chevron, Exxon Mobil and Shell, among others, worked to control public opinion. The CEIL claims a so-called Smoke and Fumes Committee was using its research "to shape public opinion about environmental issues."

Exxon in particular has faced mounting criticism over allegations it misled the public and investors about the climate impacts of burning fossil fuels. In divesting from the company, the Rockefeller Family Fund, the philanthropic arm of the family whose fortune was founded on oil, said Exxon's role was "morally reprehensible."

Carroll Muffett, president of the CEIL, said the industry was working to control the narrative from the very beginning.

"What we found is that they knew a great deal, and they knew it much earlier and with greater certainty than anyone has recognized or that the industry has admitted," she said in a statement.

Muffett last month accused Exxon of deceiving its investors after the attorney generals from 20 states announced plans to work with groups like hers on ongoing or potential investigations into Exxon's alleged behavior. The New York Attorney General's office issued a subpoena to Exxon last year following a series of reports saying the company was misleading investors.

In defending itself against the New York attorney general, Exxon said the allegations were inaccurate, deliberately misleading and charged "activists" with exploiting the issue. Most of the pressure, the company said, is politically motivated and based on reports funded by those organizations working against the fossil fuels industry.

Exxon has said its research widely mirrored the global understanding of climate issues at the time. The company last year accused climate researchers and other investigators of cherry-picking its record on the issue by largely ignoring its work on climate issues with agencies like the federal Department of Energy and the Massachusetts Institute of Technology.