Greenland is getting a lot of international attention for its mineral resources – but what is hiding under the ice?

The riches thought to lie beneath Greenland's icy terrain have been coveted for more than a century. But how easy are they to access, and will climate change make any difference?

But – despite the unbridled excitement brewing around Greenland's treasure trove – the process of finding, extracting, and transporting minerals and fossil fuels is a multilayered, multinational, and multidecadal challenge.

Everywhere on Earth, the scars and signatures of immense stretches of time are recorded in geology. Spewing volcanic eruptions and slow-cooling magmas, giant continental collisions and taffy-like rips that eventually open up new oceans – all these geologic performances are written in the rocks. And an old land mass like Greenland contains detailed documentation of the Earth's history.

"The history of Greenland goes back as far as the history of pretty much anything in the world," explains Kathryn Goodenough, principal geologist with the British Geological Survey. She explains that Greenland, once upon a time, was part of a larger continent that would have included some of northern Europe and some of North America today. Around 500 million years ago, Greenland was part of a supercontinent, wedged between Europe and North America.

But the Earth is always evolving. Around 60 to 65 million years ago, the supercontinent began to pull apart, creating a rift that eventually opened, creating the North Atlantic Ocean.

"The exploration of Greenland, especially north-east Greenland, was a hot topic 120, 130 years ago," says Thomas Find Kokfelt, senior researcher at the Geological Survey of Denmark and Greenland (GEUS). Various minerals were discovered and mines began to pop up.

Geologic mapping in Greenland began in earnest after World War Two. After 20 years of trekking along the coastline, it became clear that mapping was a humungous undertaking. "If you divide all of the ice-free areas of Greenland, you can probably fit 200 map sheets of a one to 100,000 scale," Find Kokfelt says. When the geologists did the maths, they realised it would take 200 years to finish mapping at their current rate. They pivoted to a coarser resolution effort and finished the initial geologic maps of Greenland in the early 2000s.

While critical minerals are likely in Greenland, it is unclear if mining is economically viable. That's where exploration comes in. "Mineral exploration is amongst the most challenging and risky of enterprises related to mining," says Simon Jowitt, director of the Ralph J. Roberts Center for Research and Economic Geology at the University of Nevada, Reno. He notes that for every 100 mineral exploration projects, one of them might turn into a mine.

If the exploration efforts reveal a mine's potential, on average, it can still take about 10 years to go from discovery to production, Jowitt says. "It all depends on where you are, what the infrastructure is, what permitting and other things you have to do to make sure that you're going to be mining in a conscientious way."

Processing minerals can also be a fraught endeavour. Unlike a mineral such as gold, which is found in its native state within a rock, rare earth elements are locked within another complicated mineral, explains Goodenough. "Those deposits are very, very difficult to process, and sometimes intimately connected with uranium or with other elements that you might not want to be mining."

But the waste rock was not inert.

The cold temperatures and low salinity around Greenland made environmental recovery painfully slow, and effects can still be detected 50 years later, says Merrild. "Damaging the water is really damaging the whole food supply of Greenlanders and their opportunity to have a livelihood based on fisheries and hunting."

To foster cooperation with international companies and avoid missteps, Merrild says Greenlanders should be involved in the mining process from start to finish. "People see [mining] as an opportunity, but they would very much like to take part in the development, to be co-owners, and be a part of the planning of the project," she says.