“Merchants of Doubt” is now playing at Sundance Cinemas. PG-13, 1:36, three stars out of four.

Movies have already been made about the science of climate change, from “An Inconvenient Truth” to “Chasing Ice.” Robert Kenner (“Food Inc.“) has made a movie about the anti-science.

His new documentary “Merchants of Doubt” is an engaging and enraging look at the business of climate change denying, specifically a revolving team of well-paid talking heads employed to confuse and contort the facts. When a conservative talk show host late in the film insists that the vast majority of climatologists don’t believe human behavior contributes to climate change, I sincerely think he believes what he’s saying. He’s just had so many guests spin him around that he can no longer tell up from down.

Kenner uses a recurring metaphor for this kind of spin job — a close-up magician, using misdirection and distraction to hide what is in plain sight of the viewer. The coal and oil companies who employ these spinmeisters are following the playbook of the tobacco company, who had studies going back to 1958 that said cigarettes were harmful. But, as one document from a PR firm hired by the companies put it, “Doubt is our product.”

At times, the anti-climate change lobby takes this to hilarious extremes, like releasing “mirror” reports of climate change studies that copy the layouts of the originals, but of course contain completely different conclusions. Professional deniers play rough. Kenner talks to climatologists who were pilloried for speaking out, and closes with former Republican Congressman Bob Inglis, who earned the wrath of corporate-backed groups like Americans for Prosperity when he came around on climate change.

And, to his credit, Kenner talks to the merchants themselves, including AFP’s Tim Phillips and pundit Marc Morano, the latter cheerfully admitting to posting the personal email addresses of climatologists online, unconcerned that it led to death threats. There’s no question that Kenner has an agenda here, and nobody could accuse “Merchants of Doubt” of being too even-handed, but it’s welcome to see representatives from the other side taking part.

“Doubt” ends by noting that, after 50 years, the tobacco companies’ lies finally caught up with it, and one assumes that the oil and coal industries can’t stave off action forever. The problem is, when the merchants of doubt finally run out of customers for this product, it may be too late.