Al Gore on climate-change threat: 'This is the Battle of the Bulge. This is 9/11'

Former Vice President Al Gore on Tuesday compared the seriousness of climate change to battles fought during WWII and the September 11, 2001, terrorist attacks.

"This is Pearl Harbor. This is Midway. This is the Battle of Bulge. This is 9/11. We have to rise to this challenge. We have ...