Antarctic ice sheet past point of no return
Video duration: 6:51
A study released by NASA and others offers the most definitive evidence that parts of the ice sheet in West Antarctica are melting and the damage is irreversible. The collapse will take more than a century, and the melting will lead to rising sea levels. Judy Woodruff talks to Thomas Wagner of NASA, one of the teams lead members, about the larger consequences of these projections.