Greenland's Glaciers are Melting at an Unprecedented Rate

Sunday - November 12 2023, 08:18 UTC - 1 year ago

Researchers from the University of Copenhagen have concluded that Greenland’s glaciers are melting at an unprecedented rate, with melting five times greater than it was in the 80s and 90s. The study, published in Nature Climate Change, has effectively eliminated any lingering doubts about the impact of climate change on Greenland’s glaciers, with the whole of Greenland affected by the phenomenon.

In the largest survey of its kind ever conducted, using both satellite imagery and old aerial photos from the Danish National Archives, researchers from the University of Copenhagen firmly establish that Greenland’s glaciers are melting at an unprecedented pace. Melting has increased fivefold in the past 20 years. The study eliminates any lingering doubts about the impact of climate change on Greenland’s more than 20,000 glaciers.

Based on the most comprehensive monitoring of Greenland’s glaciers to date, Danish researchers have been able to cast aside any doubt regarding the impact of climate change on the planet. Their new results document that, compared to the 80s and 90s, when glaciers shrank by an average of about five meters a year, melting has increased fivefold during the past 20 years, so that today, 25 meters per year are lost.

The new study shows the response of Greenland’s glaciers to climate change over a 130-year period. The past two decades stand out in particular, as melting during this period increased even more dramatically.

The study has been published today in the scientific journal Nature Climate Change. A number of studies in recent years have shown that Greenland’s largest glaciers are under massive pressure due to climatic changes and rising temperatures. However, doubts remained about the extent of the melting glaciers, of which there are approx. 22,000 in Greenland, partly due to inadequate measurement methods. But any doubts that may have existed before have now been dispelled by the Danish researchers.

"In this article, we make it clear that Greenland’s glaciers are all melting, and that things have moved exceptionally fast over the past 20 years. There is no doubt about the extent anymore and actually no reason to investigate the claim further," says Assistant Professor Anders Bjørk from the Department of Geosciences and Natural Resource Management.

According to the researcher, previous doubts were warranted to a certain extent. Indeed, the possibilities of investigating and documenting the extent to which glaciers melted away over extended periods of time were limited prior to the era of satellite imagery. For example, only one of Greenland’s approximately 22,000 glaciers was continuously monitored using so-called mass balance measurements, which began in the mid-1990s. At the same time, there were areas of Greenland covered by glacier that seemed unaffected by rising temperatures just a few years back.

"Previously, we saw areas in northern Greenland, for example, that were lagging behind and melting less compared to the hardest hit glaciers. This generated a bit of doubt about how serious things were in these areas. At the same time, no one before us had ever shed light on such a long period of time, which precipitated doubts as well. But now, the picture is conclusive: The melting of all glaciers is in full swing, there is no longer any doubt," says Anders Bjørk.

To gain a full overview, the researchers applied a combination of techniques. In the wake of the survey, they compared satellite-derived analyses of glacial movement over the past 15 to 20 years against visual observation of Greenland’s landscape dating back to the late 1800s.

The results illustrate that today, the loss of glacier ice has grown more intense with more glaciers melting than ever before.

“It’s clear that the whole of Greenland is affected by this phenomenon. As we melted away the glaciers, we have seen an increase in global sea levels, more intense storms, and an increase in floods due to ice and snow melting on land,” says Anders Bjørk.

Publications of similarly large surveys of how Greenland’s glaciers have changed over many decades are expected to be made public in the coming months, as the research team continues to analyze the data that has been mapped. This research is not only significant in terms of shedding light on the very real consequences of climate change, it also provides added understanding of the glacier-filled landscape of Antarctica and how it responds to rising temperature.