Activists are urging Home Depot, which recently unveiled an environmentally conscious marketing program, to withdraw advertising from Fox News, whose hosts and commentators dismiss global warming as liberal hysteria. But Home Depot is unswayed, and the environmentalists appear to be doing something they generally discourage: wasting energy.

A short video by Robert Greenwald, “Fox Attacks: The Environment,” has been viewed more than 380,000 times since it was posted on YouTube on July 9. Like his feature-length “Outfoxed: Rupert Murdoch’s War on Journalism,” the video highlights Fox News clips, in this case experts claiming that global warming caused by pollution is, among other things, a “hoax.”

In April, Home Depot introduced an Eco Options label for thousands of products that it deemed environmentally friendly.

“You can’t say we’re green and give money to an organization that day after day, week after week and month after month says that global warming is something that is made up by a few kooky scientists,” Mr. Greenwald said.