The Greenland Ice Sheet is shrinking for the 29th year in a row

Published 02-09-2025

The current melting of the ice sheet has just been assessed, as the melting season came to an end at the end of August. Although less ice has melted in the past year than in previous years, this does not cancel climate change in the Arctic, says a GEUS researcher. On the contrary, the ice sheet is facing an ominous milestone.

This year, the Greenland ice sheet has lost an estimated 105 billion tonnes of ice (Graph: GEUS)

“Even in the best years, it’s bad,” says climate researcher Signe Hillerup Larsen from GEUS. This year, once again, the calculation of the so-called mass balance of the ice shows red numbers. Very red, in fact. According to the researchers’ estimates, approximately 100 billion tonnes of ice have flowed into the ocean as meltwater or icebergs over the past year. An astronomical number, but still not as bad as it could have been.

“On average, the Greenland Ice Sheet has lost approximately 140 billion tonnes of ice per year when we look at the entire data period. So, in that light, the most recent melt year is not that bad,” says Signe Hillerup Larsen.

Since the first modern, reliable ice loss data were collected in 1985 and until now, there have been quite a few years in which several hundred billion tonnes of ice have either melted away or broken off the ice sheets’ outlet glaciers. The worst melt season to date was in 2012, when the Greenland Ice Sheet lost almost 500 billion tonnes of ice. This corresponds to the ice in the glaciers of the Alps multiplied by five.

Indlandsisens smeltevand flyder ud i fjordene og videre ud i havet (Foto: Fie Krøyer Dahl)

Is the ice melting less?

To the untrained eye, a graph of all the so-called melt years (running from September 1st to August 31st) may give the impression that the ice is melting less and less. In the past five or six years, the amount of ice that has disappeared has become lower and lower – from more than 400 billion tonnes in 2019 to approximately 100 billion tonnes this year. But unfortunately, that is not the case, says Signe Hillerup Larsen.

“It is most likely due to variations in the weather. In the 2010s, there were some years with extreme ice loss, which make the following years look less severe. But no matter what, the numbers from all the years still show the same: that the ice is shrinking. Whether it is a lot or just a little.”

30 years of ice loss next year

The overview of the annual ‘accounts’ of the Greenland Ice Sheet shows that it is now the 29th year in a row that the Greenland Ice Sheet has lost ice to the surrounding oceans. This means that for 29 years in a row, the ice sheet has lost more ice in the summer than can be replaced by snowfall the rest of the year. If that also happens next year, it will be 30 years in a row. This means that an entire generation has only experienced a decreasing Greenland Ice Sheet. And this is very likely to happen, estimates Signe Hillerup Larsen.

In climate research, 30 years is a bit of a magic number, because after a 30-year period, you can no longer say that the constant melting is due to coincidences. It is a real trend. A kind of new normal.

“This is happening because it is getting warmer in the Arctic generally, and there is no indication that this will change any time soon. Therefore, we expect the ice to continue melting even though some years might be worse than others, “ she says.

Relatively cold summer

There were times this year when Signe Hillerup Larsen and her colleagues held their breath, because it seemed like it would be another record melting year. This was because very little snow fell on the Greenland Ice Sheet during the winter, which meant that the ice wouldn’t be very resilient when summer set in.

However, it started to snow more from around February, says the climate researcher. When summer set in along with the melt season in June, there was a period of severe melting to a degree that had not been seen since the record year of 2012. Fortunately, it started to snow heavily on the ice sheet in July and August, and the snow slowed down the melting once again.

So now that summer is over, it ended up being a relatively mild year, yet still a year of loss.

GEUS researchers are monitoring the ice loss and snow gain of the ice sheet from weather stations placed all over the ice (Photo: Jason Box, GEUS)
Signe Hillerup Larsen
Researcher
Glaciology and Climate
Johanne Uhrenholt Kusnitzoff
Editor
Press and Communication

Monitoring the ice sheet

Every year on September 1st, the glaciologists at GEUS make a kind of annual assessment of the Greenland Ice Sheet. Here, they calculate how much snow fell on the ice sheet in winter and offset the melting and iceberg discharge from the summer that just ended on August 31st. This is called a melt year or a hydrological year, and it is a term that is used for glaciers and ice caps.

The calculation is part of several monitoring projects for the Greenland Ice Sheet, which were carried out in collaboration with several other research institutions in both Denmark and Greenland.

Find out more at https://promice.org/