The revelation is not surprising from an administration that’s attempting to eliminate or delay, by The New York Times’ estimate, at least 83 environmental regulations, particularly rules to curb climate pollution. The EPA is expected to announce a proposal next week to replace Obama-era power plants rules with a regulation that would, by the agency’s own estimates, allow for enough pollution to cause up to additional 1,400 premature deaths per year by 2030.

“The fact that Bill went to talk to a group like this is the cherry on top of a toxic sundae,” Joseph Goffman, a former senior counsel and associate administrator for climate who served in the Obama-era EPA, said by phone. “It’s the toxicity of the sundae that’s really going to have the damaging impact on people’s lives.”

But the emails show the degree to which top officials at the nation’s leading public health agency have cultivated chummy ties with “fringe conspiracy theorists,” the Sierra Club, which released the records obtained through a Freedom of Information Act request, said in a statement, calling the relationship “despicable.”

“It removes any illusion that the EPA is acting in good faith to ensure the public trust,” said Robert Brulle, an environmental sociologist at Drexel University.

The Cooler Heads Coalition formed in the late 1990s as mounting evidence of global warming began to fracture the industrial alliance that mobilized a decade earlier to downplay the threat of unfettered greenhouse gas emissions. A year before its merger with oil giant Mobil, Exxon gave $95,000 to the Competitive Enterprise Institute, the right-wing think tank where Ebell works, in a grant titled “Global Climate Change Program and other support,” according to documents published by the Climate Investigations Center.

Yet as the oil industry started distancing itself from widely debunked scientific contrarians, far-right philanthropists and dark-money groups stepped in to fund the Cooler Heads Coalition’s members. The financiers include the Donors Trust, Donors Capital Fund, and the foundations of the oil industrialist Scaife family, the manufacturing scion Bradley family and the Mercers, the Long Island hedge funders who backed President Donald Trump’s 2016 campaign.

That marked a shift from climate denial as a practical means of protecting carbon-polluting industries toward a new ideological fervor, enshrining opposition to climate science as a key part of anti-government dogma, said Riley Dunlap, a researcher and professor emeritus at Oklahoma State University who tracks climate denial groups.

“The Cooler Heads Coalition grew out of the frustration that industry was no longer opposing climate change as much as they thought,” Dunlap said. It’s “really a radical group of climate change deniers.”

The realities of climate change were clear to scientists even before rising seas started to inundate coastal cities like Miami on sunny days and extreme hurricanes and wildfires devastated Puerto Rico, California and Texas in recent years. At least 97% of peer-reviewed research concludes that emissions from burning fossil fuels, industrial farming and deforestation blanket the planet in gases that trap the sun’s heat in the atmosphere. A 2015 paper, meanwhile, found significant flaws in the methodologies, assumptions and analyses used by the 3% of scientists who concluded otherwise.