Exxon deliberately deceived the public about the human impact on climate change for nearly three decades, launching its campaign to deliberately spread misinformation years before global warming became a hot-button issue, according to a new report.

“The Climate Deception Dossiers” report — released Wednesday by the Union of Concerned Scientists (UCS), a U.S.-based nonprofit science advocacy organization — chronicles the deceptions of fossil fuel companies and trade groups through internal documents and memos that were either leaked to the public or disclosed through lawsuits or Freedom of Information Act (FOIA) requests.

Among the documents was an email by Leonard S. Bernstein, a former Exxon and Mobile employee who also served on the Intergovernmental Panel on Climate Change (IPCC).

“Exxon first got interested in climate change in 1981, because it was seeking to develop the Natuna gas field off Indonesia,” Bernstein wrote in an email response to an inquiry from Ohio University’s Institute for Applied and Professional Ethics. The email was first published online in October 2014.

The gas field was 70 percent carbon dioxide, which would have to be separated to make the field usable, Bernstein wrote, adding that the usual practice, then and now, was to vent the CO2 to the atmosphere. Bernstein, who first learned of the project in 1989, said if the field’s CO2 was vented Natuna would be the “largest point source of CO2 in the world.”

Bernstein said Exxon wanted to understand the potential concerns about climate change in the context of whether it would lead to regulations that would affect Natuna and other potential projects.

“Corporations are interested in environmental impacts only to the extent that they affect profits, either current or future. They may take what appears to be altruistic positions to improve their public image, but the assumption underlying those actions is that they will increase future profits,” Bernstein wrote in 2014.

Exxon on Wednesday said climate science in the early 1980s was at a preliminary stage. “There was nobody you could have gone to in 1981 or 1984 who would have said whether it was real or not. Nobody could provide a definitive answer,” Exxon spokesman Richard Keil told the Guardian.

The company now says it recognizes climate change as a risk, saying on its website that addressing greenhouse gas emissions "is one among other important world priorities, such as economic development, poverty eradication and public health."

“The scientific basis for the Greenhouse Effect and the potential impact of human emissions of greenhouse gases such as CO2 on climate is well established and cannot be denied,” Bernstein wrote in a 1995 internal memo as a Mobil chemical engineer and climate expert.

The memo, seen by Mobile and an industry group called the Global Climate Coalition, went on to say that climate change could cause an “array of climate changes” including rainfall patterns, storm frequency and intensity, as well as severe economic and environmental impacts, the report said.

But despite these warnings and other scientific evidence known at the time, Exxon publicly refused to acknowledge climate change for over 10 years and continued to provide financial support for climate denial.

In 2007, an Exxon spokesman said it had stopped funding global warming skeptics and that its position on climate change was "widely misunderstood."

Exxon spent over $30 million on think tanks and researchers that promoted climate denial, including Harvard-Smithsonian scientist Willie Soon, according to research carried out by Greenpeace.

A decade after Exxon began its assessment of Natuna, it “became a driving force in industry organizations committed to derailing" U.S. participation in the 1997 Kyoto protocol — an international treaty calling on the world’s developed nations to cut greenhouse gas emissions, Inside Climate News reported.

Exxon and other industry organizations argued that there was too much uncertainty about global warming to warrant such cuts.

Wednesday’s report includes seven “deception dossiers” containing 85 internal company and trade association documents showing a “coordinated campaign underwritten by the world’s major fossil fuel companies and their allies to spread climate misinformation and block climate action,” the report said.

Exxon knew about the connection between fossil fuels and climate change well ahead of the rest of industry and the public, the report said. Though Exxon knew first and continued funding climate denial, other industry actors also sowed uncertainty about the human role in global warming after becoming aware of scientific evidence.

Keil denied that Exxon had funded climate denial in comments to the Guardian, saying, "I'm here to talk to you about the present ... We do not fund or support those who deny the reality of climate change."

Scientists knew by the 1950s that climate change could be a risk for humanity, but it wasn’t until 1988 that it became public knowledge, after NASA scientist James Hansen testified before Congress that scientific data had confirmed human’s role in climate change, the report said. The same year, the United Nations formed the IPCC.

Despite that, in the early 1990s the internal documents included in the report show a series of carefully planned campaigns of deception by industry groups including BP, Chevron, ConocoPhillips, ExxonMobil, Shell, American Petroleum Institute (API), Western States Petroleum Association, Coal Industry and American Legislative Exchange Council (ALEC).

In 1998 API drafted a plan to secretly support “independent” researchers who would publicly dispute established climate science. The trade group’s memo claimed that “victory” would be achieved when “average citizens ‘understand’ [recognize] uncertainties in climate science,” the report said.

Similar to the tobacco industry, which was known “for its use of active, intentional disinformation and deception to support its political aims and maintain its lucrative profits,” the fossil fuel industry spread misinformation to manufacture uncertainty in the face of overwhelming scientific evidence,” the report said.