A new study finds Greenland’s melting ice sheet will likely contribute almost a foot to global sea level rise by the end of the century. Writing in the journal Nature Climate Change, researchers found that even if the world were to halt all greenhouse gas emissions today, rising levels of atmospheric carbon dioxide have already doomed 120 trillion tons of Greenland’s ice to melt. Without urgent action to mitigate the damage, researchers warn, the amount of sea level rise could be far higher.