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?

The allure of Earth's biggest island is undeniable. Over the past millennia, Greenland has captivated visitors, bringing everyone from Erik the Red, who founded the first European settlement over a thousand years ago, to the Allied Forces of World War Two to its isolated shores.

And, like the ever-warming climate, interest in Greenland is (again) heating up as the island has attracted the attention of US President Donald Trump.

Detailed mapping collaborations and explorations carried out over more than a century have uncovered evidence of important mineral resources in Greenland – including rare earth elements and critical minerals used for green energy technologies, as well as suspected fossil fuel reserves.

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.

On most maps, Greenland looks enormous, rivalling the size of Africa. Blame this exaggeration on the popular Mercator map projection, which stretches and enlarges countries near the poles, exaggerating their size. In reality, Greenland is around 2m sq km (770,000 square miles) – roughly the size of the Democratic Republic of Congo.

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.