Cold War Greenland base was ice-free 416,000 years ago, summers 4.7°C warmer

A forgotten Cold War military base buried beneath Greenland's ice is giving scientists an unusual glimpse into a much warmer Earth. Researchers examined sediment recovered from Camp Century in northwestern Greenland, a site built by the US Army Corps of Engineers in 1959 and abandoned in 1967.

The sediment contained biological markers that allowed scientists to reconstruct summer temperatures and moisture conditions about 416,000 years ago, during Marine Isotope Stage 11. They found that summers were about 4.7°C warmer than modern conditions, while the site was ice-free despite now sitting beneath 1,387 metres of ice.

The findings offer new clues about Greenland's sensitivity to prolonged warmth.Camp Century was built during the Cold War beneath Greenland's iceCamp Century was constructed by the US Army Corps of Engineers in 1959 beneath the surface of the Greenland Ice Sheet. The facility was part military experiment and part research station, with the US Army investigating whether infrastructure and ballistic missiles could operate beneath the ice.