The scientific community is raising the alarm over a concealed Cold War-era risk lurking beneath Greenland’s swiftly diminishing ice sheet.

A relic of the past, the US military installation known as Camp Century, has come back into focus. This rediscovery occurred when a NASA pilot, engaged in radar testing from above, captured images revealing the remnants of this hidden base.

Originally built in secrecy during the Cold War, the base is positioned approximately 118 feet below the ice surface, extending over an area around 0.7 miles long and 0.3 miles wide.

Once touted as an underground self-sustaining community, Camp Century included facilities like a hospital, theater, church, and shop, all powered by a compact nuclear reactor.

With the ice in Greenland retreating at an alarming pace, experts have expressed concerns that the toxic waste left at the site might eventually seep into the surrounding environment.

That waste includes chemical pollutants, biological sewage, diesel fuel, and radioactive material once thought to be safely sealed in ice forever. 

Researchers now say that assumption was deeply flawed. ‘What climate change did was press the gas pedal to the floor,’ said James White, a climate scientist at the University of Colorado Boulder.

Camp Century was constructed in the late 1950s with the knowledge of both the US and Danish governments under the 1951 Defense of Greenland Agreement. 

NASA scientists captured an image of an abandoned US military base that has been hiding under ice in the

Camp Century was constructed in the late 1950s with the knowledge of both the US and Danish governments under the 1951 Defense of Greenland Agreement

Danish officials participated in planning and environmental monitoring, and historical reports indicate Denmark approved the disposal of some radioactive waste directly into the ice. 

At the time, scientists and military planners believed Greenland’s ice sheet would permanently entomb any contamination.

‘That idea, that waste could be buried forever under ice, is unrealistic,’ White said. 

‘The question is whether it’s going to come out in hundreds of years, thousands of years, or tens of thousands of years. Climate change just means it’s going to happen much faster than anyone expected.’

The environmental risk posed by Camp Century has taken on new urgency as geopolitical tensions in the Arctic intensify. 

President Donald Trump renewed calls this week for US control of Greenland, citing national security concerns as Russian and Chinese activity in the region grows. ‘It’s so strategic,’ Trump told reporters aboard Air Force One on Sunday. 

‘Right now, Greenland is covered with Russian and Chinese ships all over the place. We need Greenland from the standpoint of national security.’

But scientists said the buried base represents a very different kind of security threat, one tied not to military rivals, but to pollution unleashed by a warming climate.

Once described as a self-contained underground town, Camp Century housed a hospital, theater, church and shop, and was powered by a small nuclear reactor

Pictured are US soldiers climbing up to an escape hatch to enter Camp Century

A team of international researchers led by the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder estimated that Camp Century contains roughly 9,200 tons of physical waste, including abandoned buildings, tunnels, and rail infrastructure. 

The site also holds about 200,000 liters of diesel fuel and significant amounts of polychlorinated biphenyls, or PCBs, toxic chemicals once widely used in paints and electrical equipment.

PCBs are especially concerning because they do not break down easily and are linked to cancer, immune system damage, and developmental problems. 

The Arctic’s cold climate has trapped these chemicals for decades, effectively turning the region into a global storage site for pollution released elsewhere. 

As ice melts, however, scientists warned that glaciers could become a new source of toxic contamination.

Most former Arctic military sites have undergone cleanup efforts, but Camp Century is one of only five abandoned ice-sheet bases near Thule Air Base that have never been remediated, according to the 2016 study by the CIRES research team. 

Camp Century is a US military base built in 1959 that consists of a network of 21 tunnels but just below the surface of the ice sheet ice 

Pictured is the entrance to the base before it was decommissioned in 1967

At similar sites, PCB concentrations in some paints exceeded five percent by weight.

In addition to chemical and biological waste, Camp Century also contains radioactive material from the nuclear reactor’s coolant system. 

When it was buried in the early 1960s, the waste had a radioactivity of about 1.2 billion becquerels, roughly equivalent to the radiation used in a single medical scan. 

While small compared to major nuclear accidents, researchers cautioned that its presence adds another layer of risk if containment fails.

The base’s tunnel system twists and branches beneath the ice, making it difficult to fully map. 

Airborne radar has detected strong reflections that align with known tunnel locations, but scientists say the technology cannot yet identify all buried waste. 

Diesel fuel, stored in underground tanks, may still be liquid today, though researchers believe the tanks may have ruptured.

Models suggest that ice flow and snow accumulation could bury solid waste as deep as 220 feet and liquid waste around 305 feet by 2090. 

While that means contamination may not surface for decades, scientists stressed that burial does not equal safety.

Camp Century was constructed in the late 1950s with the knowledge of both the US and Danish governments under the 1951 Defense of Greenland Agreement.

Beyond the environmental risks, Camp Century has become a source of political and legal uncertainty. 

Responsibility for the cleanup remains disputed between the US, Denmark, and Greenland. 

While the waste was left behind by the US, the original 1951 treaty did not account for climate change or Greenland’s growing self-governance.

The agreement states that US property in Greenland may be removed or disposed of after consultation with Danish authorities. 

But it remains unclear whether Denmark was fully consulted during Camp Century’s decommissioning, raising questions about whether the abandoned waste is still legally US property.

Researchers said Camp Century may represent one of the first real examples of climate change triggering an international dispute over long-forgotten pollution, a preview of conflicts likely to emerge worldwide as rising seas and melting ice expose hazardous waste once thought safely buried.