[Motherboard.vice] About 60 years ago, at the height of the Cold War, the US designed a network of top-secret mobile nuclear launch sites buried in the Greenland ice sheet to prepare for possible war with the Soviet Union. At Camp Century, which was part of Project Iceworm, soldiers lived in the ice, which enclosed the base so it wouldn’t be completely buried in snow.

Camp Century was shut down in 1967, and the site was abandoned as Project Iceworm wound down. Back then, military planners assumed the hazardous stuff buried at Camp Century—including diesel fuel, PCBs, and some radioactive coolant—would stay locked up in the Greenland ice sheet, essentially forever. But now Greenland is warming. Dangerous contaminants threaten to re-emerge from the ice, potentially putting people in Greenland and maybe as far away as Arctic Canada (400 km offshore) at risk.