7,000 years ago, Greenland’s giant ice dome disappeared as temperatures climbed. Today, scientists say the ancient melting occurred at temperatures close to those now threatening the island’s remaining ice

Greenland’s 1,600-foot ice dome vanished 7,000 years ago when temperatures were several degrees warmer than today. Now, scientists have found the buried evidence beneath Prudhoe Dome. The discovery raises a difficult question about Greenland’s future. Similar warmth could return by the end of this century. If that happens, the ancient melt record could offer a rare clue to how quickly Greenland’s ice may respond and what it could mean for global sea levels.