Fox News contributor Deroy Murdock says that that there are "hundreds of thousands" of scientists "on both sides" debating if climate change is real.

In a Sunday appearance on Fox News, Murdock, who also writes for Scripps Howard News Service and National Review Online, told anchor Eric Shawn that six Apollo astronauts had written a letter asking NASA to stop making "unproven remarks" about global warming.

"What they're doing is asking NASA to stop putting up press releases and making statements saying that man-made carbon dioxide is is causing a catastrophic warming of the planet," Murdock explained. "I think this is very significant because people who are pro-global warming very often will dismiss skeptics of global warming theory as flat-earthers, knuckle-dragging idiots, people who are anti-science. And it's very hard to call anti-science two men who have walked on the moon and two others who have circled around the moon but not landed. And in total, 49 other people at NASA who said, 'Look, you need to stop pushing this theory. It's not proven, the science is not settled. Get off of it.'"

"In terms of what the astronauts say, some critics are saying that they made false claims in this letter," Shawn noted. "It's really a controversial issue, especially with other scientists saying that there obviously is man-made global warming."

"I think that's one of the points, that there are scientists on both sides," Murdock replied. "There are hundreds of thousands on both sides debating this. And yet, the sort of Al Gore side has said, 'Oh well, this is settled, we don't need to talk about this, let's just start the regulations and do cap and trade and so on because this is settled.' And clearly there are many scientists on the other side saying, 'No, no, this isn't settled, this needs to be discussed and debated.'"

A 2009 study (PDF) by University of Illinois at Chicago professors Peter T. Doran and Maggie Kendall Zimmerman found that over 97 percent of climate scientists were convinced that the Earth was warming.

In 2010, researchers from Stanford University, the University of Toronto and the William and Flora Hewlett Foundation used a "an extensive dataset of 1,372 climate researchers" and determined that 97-98 percent agreed on the tenets of anthropogenic climate change (ACC).

But according to a May 2011 survey (PDF) by the Yale Project on Climate Change Communication, 57 percent of Americans think that less than 80 percent of scientists agree that global warming is real.

Earlier this year, NASA’s Goddard Institute director James Hansen charged that "[p]eople profiting from business-as-usual fossil fuel use are waging a campaign to discredit the science" by manipulating the media.

"Today most media, even publicly-supported media, are pressured to balance every climate story with opinions of contrarians, climate change deniers, as if they had equal scientific credibility," Hansen wrote in a January letter (PDF). "Media are dependent on advertising revenue of the fossil fuel industry, and in some cases are owned by people with an interest in continuing business as usual."

An analysis by the liberal watchdog group Media Matters found that coverage of climate change on Sunday morning news shows had declined by 90 percent between 2009 and 2011.

Watch this video from Fox News' America's Election News Headquarters via Media Matters, broadcast Mat 13, 2012.