Greenland crisis strains Danish research ties with US

Danish ice-core research in Greenland has long depended on close cooperation with the United States, but rising geopolitical tensions are making those partnerships less certain, DR reports.

Researchers also rely heavily on the US military, including ski-equipped Hercules aircraft, to reach the Greenland ice sheet. Lin Alexandra Mortensgaard, a postdoctoral researcher at the Danish Institute for International Studies, says the aircraft illustrate the close link between climate research and security policy in the Arctic.

“The planes themselves show very clearly the close connection between climate research and security policy in the Arctic,” she says.

Mortensgaard visited the Danish research station EastGRIP on the ice sheet while working on her PhD, examining how dependent researchers are on US support to carry out ice-core drilling in Greenland. The aircraft provide opportunities for research, she says, but also create concrete challenges and dependencies that have become more visible under the Trump administration.

US President Donald Trump has shown that he is willing to shut down climate research, Mortensgaard says. One possible outcome is that he could cut support in an effort to take a hard line against what he calls “woke science”, a category in which he places climate research.

However, she says there may be less risk in this case that the US will withdraw the aircraft and end its support, because the planes also serve as a way for the United States to demonstrate its presence in Greenland.

Greenland institutions halt new US partnerships

Ice-core research from Greenland has provided important knowledge about the climate of the past. Researchers have developed a climate record for Greenland covering the past 120,000 to 125,000 years. Ice cores from the Arctic and Antarctic can also show how high sea levels were when Earth’s temperatures were higher, providing an indication of how sea levels could develop in a warmer climate.

Denmark’s Prime Minister Mette Frederiksen has described dealing with Trump’s repeated wishes to make Greenland part of the United States as “the most difficult foreign policy situation since the Second World War”.

The US president’s rhetoric towards Greenland and Denmark has also affected the research community. Pinngortitaleriffik, Greenland’s Nature Institute, announced this summer that it would no longer enter into new projects with the United States. Ilisimatusarfik, Greenland’s University, has also stopped starting new partnerships with the US, according to KNR.

The same concerns are being seen in Canada, Mortensgaard says. Some Canadian researchers have independently ended collaborations with American colleagues and institutions because they fear that US institutions could misuse, or be forced to misuse, their knowledge and data.

In May, Danish marine biology expert Peter Teglberg Madsen told Politiken that he had turned down a collaboration with the US federal agency National Oceanic and Atmospheric Administration in 2025. He said he made the decision after Trump threatened to take over Greenland and because he feared becoming a piece in the political struggle over the island.

Mortensgaard says the concerns and potential risks associated with cooperating with US institutions are unlikely to disappear soon.