Climate Scientists Found A Surprise Hiding Under A Cold War Military Base

During the Cold War, the U.S. Army devised a secret plan to hide nuclear missiles inside of Greenland's ice sheet. While the missiles never actually arrived, scientists found something more interesting below the surface: sediments that could teach us more about Greenland's history with climate change. A new study published in Climate of the Past found that the site of the plan was completely free of ice around 416,000 years ago. Back then, the Greenland summers were about 8.5 degrees Fahrenheit, or 4.7 degrees Celsius, warmer than they are today. BGR reported that for the location, known as Camp Century, to be ice-free, the study says the Greenland Ice Sheet would have had to retreat more than 60 miles, or 97 kilometers, from where its edge sits in that part of Greenland today.

John Michael Aguilar, the study's first author and a postdoctoral fellow at the University at Buffalo, stated that it is striking a period of moderately warmer temperatures coincided with such a substantial retreat of the ice sheet. The researchers believe they may have discovered the cause of this by studying sediment and concluding that the length of the warm time period may be just as important as how much warmer it was. Between 5,000 and 10,000 years ago, Greenland had similar summers, but the ice at Camp Century didn't melt away because the warm period 416,000 years ago, known as Marine Isotope Stage 11, could have gone on for tens of thousands of years, giving the ice sheet more time to melt and shrink. Elizabeth Thomas, the study's corresponding author, noted that today's human-caused warming is more intense than the warm period 400,000 years ago, and climate projections suggest this warmth could persist for hundreds or thousands of years.

Camp Century was built in 1959 by the U.S. Army Corps of Engineers beneath the ice in northwestern Greenland to test whether Project Iceworm, a plan to keep missiles inside the ice, was possible. The base was abandoned in 1967 after the plan did not work out, but drill crews had made it almost a mile down to the bottom of the ice. Chester Langway, the scientist in charge of drilling at Camp Century, took the sediment back to the University at Buffalo in 1975, and it later ended up at the University of Copenhagen where it went unnoticed for more than 20 years until turning up during a freezer cleanout in 2018. To figure out the past temperatures, researchers looked at fatty molecules left behind by bacteria in the sediment, comparing them with similar molecules found in modern Arctic lakes, with the estimate carrying a margin of error of 5.7 degrees Fahrenheit, or 3.2 degrees Celsius.

Separately, Military.com reported that a declassified Cold War-era U.S. Army proposal envisioned turning the ice sheet into an underground missile complex with up to 600 nuclear-armed missiles concealed in roughly 2,500 miles of tunnels. The installation served as a practical test of whether tunnels cut through the ice could provide concealment, protection, and logistical support for strategic weapons. However, operating a network of that size beneath moving ice that shifts, compresses, and deforms over time would have presented substantial engineering, maintenance, and environmental challenges.