The Greenland Ice Sheet recorded a new record mass loss in 2019. A team of international polar researches came to this conclusion in Nature Communications Earth & Environment by evaluating satellite observations and data from computer models.
In State of the Climate, published earlier this month, the researchers show that other glaciers in the Arctic region have also been severely affected by the summer of 2019. And in yet another publication in Nature Communications Earth & Environment last week, they show that the future looks grim for the Greenland Ice Sheet: even if the climate cools, Greenland’s glaciers will continue to lose mass.
Record ice loss
With 532 billion tons, total mass loss of the Greenland Ice Sheet was higher than in the previous record year 2012 (464 billion tons), corresponding to a global mean sea level rise of 1.5 mm. After two years of reduced melting in 2017 and 2018, the ice sheet is now back on the path of increasing mass loss. The five biggest years of losses have occurred in the past decade.
Artic glaciers taking a punch
Arctic glaciers felt the heat of 2019 too, and took a big punch, according to the researchers in the State of the Climate 2019, the annual summary of the global climate published as a supplement to the Bulletin of the American Meteorological Society. Bert Wouters (Utrecht University / TU Delft): ‘The record mass loss of 2019 of the Greenland Ice Sheet is in line with the general picture of a rapidly warming Arctic. The other, smaller glaciated regions in the Arctic, such as Alaska and Arctic Canada, experienced extreme summer melt as well that year, with a loss of ice unprecedented since the start of the satellite measurements. Within a few months, they lost about 700 cubic km of ice.”
Part of this was winter snow, leading to a net loss of 510 km³ for 2019. That’s more than three times the usual ice loss between 2002 and 2018, as measured by the GRACE and GRACE Follow-On (GRACE-FO) satellite missions, and comparable to the ice loss of the much larger Greenland Ice Sheet that summer.
Greenland Ice Sheet now in state of persistent imbalance
With a longer-term view: nearly 40 years of satellite data from Greenland show that glaciers on the island have shrunk so much that even if global warming were to stop today, the ice sheet would continue shrinking for many years to come. The finding, published August 13 in Nature Communications Earth and Environment, means that Greenland’s glaciers are now is in a state of persistent imbalance, where the snowfall that replenishes the ice sheet each year cannot keep up with the ice that is flowing into the ocean from glaciers.