Skeptic No Longer Doubts Human Role in Global Warming

Aired: 9/17/2012 | 0:10:25 | Clip
Physicist Richard Muller was one of the scientists who denied climate change and humans' role warming the earth. But after spending years researching and analyzing countless studies, Muller concluded climate change scientists were right, that humans had contributed to the rise in the earth's temperature. Spencer Michels reports.