Al Gore’s crusade to save the world

A huge iceberg — said to be the size of Delaware — broke off from the Antarctic Peninsula. It’s one of the largest ever recorded. But scientists differ on whether it can be blamed directly on climate change. Still, former Vice-President Al Gore called the floating giant "a jarring reminder of why we must solve the climate crisis." Gore has been a crusader on that issue for years now, and took Lee Cowan back to Tennessee to take stock of the battle in our "Sunday Morning" Cover Story:

Lee Cowan

Video: http://www.cbsnews.com/news/al-gore-crusade/