PBS NewsHour

Visiting the 'doomsday glacier' that’s melting away

Clip: 02/19/2020 | 9m 8s | Video has closed captioning.

The Thwaites Glacier is the largest, most menacing source of rising sea levels all over the world, and it is melting at an alarming rate. For years, scientists have warily watched it from afar, but in November, a team set out on a perilous journey to investigate what is happening below. Science correspondent Miles O’Brien reports on what they discovered.