Tuesday night on "Jimmy Kimmel Live," former Vice President Al Gore said people who denied that humans were negatively influencing the Earth's climate were simply crazy.
"Some of the same people that were denying that it would be bad to default on the debt -- they say, 'There's no problem, we can just pay the Chinese bond holders instead of Social Security recipients or the military' -- well, that is sort of the same as saying physics isn't real, global warming isn't real," Gore said.
"It's nuts," he continued. "It really is nuts. And it is hard to just say it is nuts, but it is nuts."
"Every national academy of sciences in the world has taken this position, every scientific society 97 percent of all climate scientists -- and mother nature is really kind of screaming from the rooftops."
Gore said there should be an economic cost on carbon and a political cost on climate change denial.
Watch video, uploaded to YouTube, below: