Remember the representatives of Big Tobacco claiming that there was no scientific evidence linking smoking and lung cancer? When that didn't fly anymore, they hired PR firms to put on a campaign saying that to limit the individual's tobacco products would lead to a restriction on freedom of choice. By coming up with one manipulative, dishonest, and doubt-inducing campaign after another, these corporations and their CEOs managed to stall regulation of the tobacco industry for 50 years. It is a disgrace to tally up the deaths of so many people whose lives were sacrificed so that the tobacco companies could make more money.

This hard-hitting documentary by Robert Kenner (Food, Inc.) takes on the cult of denial which has been operative in nearly every public health and environmental crusade. The filmmaker discovers that a small, well-funded, highly disciplined, and ideologically zealous band of warriors are now spreading disinformation and misinformation about climate change. They are convinced that environmentalism leads to "big government" and puts in jeopardy our free market capitalist system. One of their favorite slogans from the Cold War era was "green on the outside, but red on the inside."

Whereas the scientific establishment has taken a stand based on factual evidence for the human causes behind climate change, the media have given doubt-mongers an equal chance to express their opinions. This has allowed a very small group of people to have a large influence in shaping public opinion and policy on climate change.

Kenner profiles two major players in this battle: former Congressman Bob Inglis, a South Carolina Republican who switched sides when he accepted the evidence of climate change. He still struggles to convince conservative and libertarians to change their minds but seems to be fighting an uphill battle. Then there is Marc Morano, a seasoned veteran of climate change misinformation who admits his lack of scientific credentials and to smearing opponents with gigantic email attacks.

Merchants of Doubt shows how the political power of corporations, think tanks, and lobbyists have had a significant impact on the American public's assessment of global warming.