Alaska is warming up. It's now a few degrees warmer than it was a century and a half ago, and the trend seems to be accelerating. Already the landscape is changing dramatically -- permafrost is thawing, glaciers are melting, forests are succumbing to drought and insect attack. Alan Alda meets Alaskan scientists who are working to find out if these are the first signs of global warming and what the future may hold.
Download the TV Guide app for iPhone, iPad and Android!