The real value of Greenland is in the ice, rather than the minerals

When Donald Trump raised the possibility of purchasing Greenland from Denmark, his critics in the US had to pause and regain their balance. But how preposterous was this idea?

Initially, debates in the US focused around the possible logistics of a deal. And what soon became clear is that Greenland, the world’s largest island, is a semi-autonomous nation that is not for sale and never will be. What’s more, Denmark, whose prime minister aptly called Trump’s gambit “absurd,” couldn’t sell Greenland even if it so desired.

Some good may still come from this awkward diplomatic moment. At least in America, we’ve awakened to the idea that this arctic island is far more important than most of us previously believed. Not only does Greenland have extraordinary reserves of rare-earth metals that are crucial to the manufacture of electronics equipment. Its location, near to an increasingly belligerent Russia, makes it an important geostrategic partner.

Read more about climate change:

• Can planting billions of trees help tackle climate change?
• The effects of the Little Ice Age went far beyond climate change
• Antarctica is “getting greener” due to climate change

And yet, there’s something far more important about the island than its potential for wealth and military deterrence. Greenland’s ice sheet, which covers about 80 percent of the island, is melting at an alarming rate, dumping freshwater and icebergs into the north Atlantic over the past decade at an average of about 280 billion tons per year.

This past summer has almost certainly exceeded that rate, with the ice sheet suffering through an extraordinary “melt event” in mid-June and another starting in late July. At times, the temperatures in Greenland ranged 9 °C above average, and on a single day of extreme melting, scientists calculated the island lost about 11 billion tons of ice.

Martin Stendel, a researcher at the Danish Meteorological Institute, calculated that during a two-day period in August, Greenland’s losses were enough to cover the entire state of Florida in 12 cm of water. That happens to be roughly the same area as England and Wales combined.

We need to think of the threat from Greenland’s ice as both near to us and far. Bombarded online by arresting digital images — of brilliant blue lakes and azure rivers flowing from the ice sheet — we can only make out small details of a complex bigger picture.

For the past five years, I’ve been travelling from the US to this stark and beautiful arctic island in an attempt to understand both its past and future. In many respects, I’ve come to see that the story of Greenland is written in its ice.

Hundreds of thousands of years ago, snowfalls began to accumulate in the centre of this island that did not melt during the summers. In time, those fields of snow fused together and compacted into ice, to the point that Greenland’s frozen white shroud stretched over a region that is now about 2,400 km long and (at its broadest) 1,100 km wide. In its center, the ice cap rises to an elevation of 3,000 metres — 3,000 metres of pure ice, all the way to bedrock.

This is the last large remnant of the ice sheets that covered northern Europe and North America during the last ice age, some 20,000 years ago. As global temperatures warmed, the other sheets of ice melted and shattered into the oceans, raising sea levels dramatically in the process. Yet Greenland’s ice has endured. That is, at least until now.

The most worrisome aspect of Greenland’s receding ice relates to the spectre of future floods. Even with extreme summer melts, it contributes only about 1 mm per year, on average, to rising sea levels, which are also elevated by melting land glaciers around the world and by Antarctica’s calving icebergs. (Another factor is that ocean water expands in warmer temperatures.)

What’s important to remember, though, is Greenland’s potential. All told, the island holds enough ice to increase ocean levels by about seven metres, according to recent measurements by NASA. So, while its current contribution to our seas might now seem modest, the rate of its losses, according to several recent academic studies, appears to be accelerating.

Discover more about climate change on the Science Focus Podcast:

• How accurately can we predict the weather? – Andrew Blum
• How can we save our planet? – Sir David Attenborough
• Are we facing an insect apocalypse? – Brad Lister

Also, here’s what worries me even more: The digital images we see online convey the idea that Greenland is in the midst of a meltdown. The actual truth is that projections for the future of the ice sheet suggest its collapse may have only begun.

As the world continues to warm in the decades ahead — and at the moment, global CO₂ emissions continue to increase, rather than decrease — Greenland’s contribution will become extreme, with the ice sheet losing more and more as the century progresses.

What’s more, computer models suggest that the rate of melting beyond the year 2100 looks to be calamitous. One of the most frightening aspects of this future trajectory is that the island’s ice seems vulnerable to a number of self-reinforcing feedbacks that could accelerate its demise to the point that it cannot be stopped.

A good example of these kind of loops is how the ice sheet, especially in the southwestern region, is getting darker, due largely to dust and soot that have settled on the ice, and to algae blooms that spread in warmer temperatures. The effect is to lower the surface reflectivity and allow the ice to absorb more solar energy — thus melting it more and darkening it even further. So it’s crucial to understand that the more Greenland melts now, the more likely it is to melt more in the future.

Can the ice sheet survive? A number of scientists I spoke with during the course of my reporting believe we have arrived at a critical juncture. Within the next few decades, summertime temperatures on the island may rise too high, and Greenland’s melting may thus progress too far for the ice sheet to endure. Over seven metres of water will not slide into the ocean overnight; it will likely take many centuries for it all to disappear. But Greenland’s fate — and in turn, the fate of the world’s coastlines — appears to be determined by what we do in the immediate future to arrest the course of climate change.

In other words, while we debate the logistics of whether America’s president could ever buy the island, this ice sheet moves closer to a catastrophic point of no return. Iceberg by iceberg, drop by drop, it is falling into our oceans. We might therefore pause to ask whether it really matters who owns Greenland. Right now, we all do.

Follow Science Focus onTwitter,Facebook, Instagramand Flipboard