Speaking to CBS News host Katie Couric, former Vice President Al Gore panned climate change skeptics, comparing them to people who believe the world is flat, or those who doubt that NASA's Apollo mission actually landed on the moon.

"The United Nations organized, along with the scientific bodies of the national academies of science and their counterparts, the 3,000 best scientists in the world from all of the fields that are relevant to this issue," he explained. "Over the last 20 years they have conducted the most exhaustive examination ever on a challenge like this.

"They've issued four reports -- they've all been unanimous, and the last one called the evidence unequivocal. Now, does that mean there are still some people who are gonna have a contrarian view? No, of course there will still be some. But, there are still some people who believe that the moon landing was staged on a movie lot. You know, a significant percentage as it turns out ... Or that the Earth is flat. But that doesn't lead public policy makers to take both sides of that into account."

The man who many argue to have won the 2000 U.S. presidential election also praised the upcoming global climate summit in Copenhagen. He said that in order for the summit to be successful in formulating a new set of rules to govern emissions, the U.S. Senate must pass climate legislation. "Then we have to get a treaty that yes, can be ratified," he said.

However, the hurdles facing both of those potentially landmark documents seem to be growing.

Though Gore said he believes the U.S. Senate will pass climate legislation, it will "face a stark political reality when it emerges for committee debate on Tuesday: With Democrats deeply divided on the issue, unless some Republican lawmakers risk the backlash for signing on to the legislation, there is almost no hope for passage," The Washington Post reported Monday.

Senate Republicans are also taking up for Sen. Jim Inhofe's (R-OK) boycott of the bill's legislative markup in committee: an effort they hope will prevent it from moving on to the body at-large.

Additionally, with the Copenhagen meeting mere weeks away, it may be "physically impossible to finalize all the details of a treaty," Yvo de Boer, executive secretary of the UN Framework Convention on Climate Change, told reporters recently. Instead of expecting a climate treaty to emerge from the summit, he said to look for "a set of decisions" that would clarify the complex politics, allowing space for the treaty's details to be worked out.

This video is from CBS, broadcast Nov. 2, 2009.

[youtube http://www.youtube.com/v/syRvnJ9lbqY&hl=en&fs=1& expand=1]

This video is from CBS, broadcast Nov. 2, 2009.

[youtube http://www.youtube.com/v/3EWYp4mfWnM&hl=en&fs=1& expand=1]