Greg Zimmerman, an environmental activist, was scrolling through the website of a coal industry association when he came across a presentation that startled him: “Survival Is Victory: Lessons From the Tobacco Wars.”

What surprised Mr. Zimmerman, the deputy policy director at the Center for Western Priorities, a conservation advocacy organization based in Denver, was that the coal industry was, at least in this presentation, deliberately drawing a comparison between itself and the tobacco companies.

That is more typically the argument of environmentalists, who often compare fossil fuel companies to the tobacco industry. They note that the tobacco giants for many years funded trumped-up science and advocacy groups to spread doubt about risks of smoking.

Fossil fuel companies, they argue, have engaged in similar efforts, and investigations by state attorneys general have focused on the tactics of Exxon Mobil, which has funded groups that deny the scientific evidence that human activity has increased global warming. Fossil fuel companies and their allies generally ridicule the comparison to tobacco.