In this video segment, a team of scientists seeks evidence to support their hypothesis that atmospheric warming -- either now or in the past -- may explain why water has formed beneath the West Antarctic ice sheet, causing ice streams that flow much more quickly than the rest of the ice sheet. This phenomenon has important implications for potential sea level rise.

This is a video that documents the reflections of members of the Steger International Polar Expedition team reunited at the 25th anniversary of their landmark trek to the Arctic, and how climate change has made their trek difficult to replicate.