Researchers record record ice loss in Greenland

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Icebergs swim in the sea off the Greenland coast

The negative record had already emerged: the decline in the Greenland ice sheet reached a new record in 2019. The loss of mass was greater than in the previous record year 2012. This is the result of a study by the Bremerhaven Alfred Wegener Institute (AWI) and the Potsdam Geo Research Center (GFZ). For the study, which appeared in the journal "Communications Earth & Environment", the scientists analyzed satellite and model data.

In 2017 and 2018 there were only minor losses of mass. "After a two-year pause for breath, the mass losses rose sharply again in 2019 and exceeded all annual losses since 1948, probably for more than 100 years," said Ingo Sasgen, glaciologist at the AWI in Bremerhaven and author of the study. The inland ice - also known as the ice sheet - is an area-like glaciation that almost completely covers Greenland.

The inland ice in Antarctica and that in Greenland are the largest ice sheets on earth. The fact that the glaciers lose ice into the sea is part of the natural cycle. But usually they also gain new ice from freezing, fresh snow.

The mass balance of a year results from the difference between ice increase and ice loss due to melting and ice discharge at the edge into the ocean. The mass losses in Greenland were reported to be 532 billion tons in 2019, significantly higher than in the previous record year 2012 (464 billion tons). This corresponds to a global mean sea level rise of 1.5 millimeters. "More and more often we have stable high pressure areas above the ice sheet, which favor the influx of warmer air from the middle latitudes and thus the melting," said Sasgen.

The system can no longer be stopped

It was different 40 years ago. The snow that accumulated on Greenland and the amount of ice that melted or the glaciers released into the ocean in the form of icebergs were in balance, although even then huge amounts of ice from glaciers flowed into the sea. From the year 2000, the system overturned.

Researchers had already drawn attention to this in mid-August. A team from Ohio State University reported that Greenland's ice loss is accelerating and unstoppable even if global warming is stopped immediately. Since 1985, the glaciers on Greenland have retreated around three kilometers on average. The annual snowfall is no longer enough to make up for these losses, according to satellite data from 40 years.

joe / dpa