Summary: <p>CAN SCIENCE EXPLAIN EXTREME WEATHER?: A rare winter weather pattern has plunged Washington and much of the country into single-digit temperatures. Some researchers believe the "polar vortex" that's delivered unusually cold air is linked to melting sea ice in the Arctic. And many activists and scientists believe extreme weather events are becoming more prevalent due to climate change. We examine scientific and political arguments about extreme weather. (52 min.)</p>
