Arctic Mission with David Shukman

The Arctic is the fastest-warming region on Earth, and its fate is one of the biggest unknowns in climate science. If the polar ice retreats, it could accelerate the rise in global temperatures and significantly change the world's weather patterns. A team of Norwegian scientists has spent the winter on a research ship in the Arctic examining the sea ice. They say it's becoming thinner and more likely to break up. David Shukman has been aboard their ship.