When a team of scientists from Switzerland and Denmark landed by helicopter on a small island off the northern coast of Greenland in July, they didn’t think much of it. It was just “one of a hundred sites” the team visited, says expedition leader Morten Rasch, while collecting samples for themselves and other scientists around the world. They had had a hard time finding their destination—called Oodaaq Island—but eventually were able to land and spend about 15 or 20 minutes before taking off again. “It was nothing big for us,”…