Endangered North Atlantic right whales are disappearing from their native waters, a serious danger for a species with only 340 animals left. The mystery behind this change took NPR's climate reporter Lauren Sommer 2,000 miles away to the world's second-largest ice sheet, sitting on top of Greenland. On today's episode, Lauren takes Short Wave co-host Emily Kwong on an expedition to Greenland's ice sheet and then to the Gulf of Maine to break down the ripple effects of climate change. Reach the show by emailing shortwave@npr.org.