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Scientists say Greenland’s ice loss jumped again last year, breaking the previous record of 15%.
New analysis indicates the scale of the melting was “unprecedented” in records dating back to 1948.
The high pressure systems that crashed in Greenland last summer were the immediate cause of the huge losses.
But the authors say the continued carbon emissions are pushing Greenland into a more extreme melting era.
Over the past 30 years, Greenland’s contribution to global sea level has increased dramatically as ice loss has increased.
A major international report on Greenland published last December concluded that it was losing ice seven times faster than in the 1990s.
Today’s new study shows that this trend continues.
Using data from the Grace and Grace-FO satellites, as well as climate models, the authors conclude that throughout the year Greenland lost 532 gigatonnes of ice – a significant increase from 2012.
The researchers say the loss is equivalent to adding 1.5mm to the global average sea level, or about 40% of the average rise in a year.
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Steffen Olsen
Climatologist Steffen Olsen took this photo while traveling on melted sea ice in northwest Greenland in 2019
According to a calculation by Danish climatologist Martin Stendel, losses in 2019 would be sufficient to cover the whole of the UK with around 2.5 meters of meltwater.
Last year and 2012 were marked by “blocking” events, the researchers say, where disturbances in the jet stream caused the high pressure systems in Greenland to block, resulting in increased melting.
“It seems that we have entered an increasingly extreme melting kingdom in Greenland,” said lead author Dr Ingo Sasgen of the Alfred Wegener Institute in Bremerhaven, Germany.
“Something like the years 2019 or 2012 is expected to repeat itself. And we don’t know exactly how the ice behaves in terms of the feedback mechanisms in this vigorous range of melt.”
“There could be … hidden returns that we are not aware of or that may not be fully depicted in the models at the moment. This could lead to some surprises.”
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Although 2019 broke the record, ice losses in 2018 and 2017 have declined, lower than in any other two-year period since 2003.
The authors say this was due to two very cold summers in Greenland followed by heavy snowfall in the fall.
However, the return to high levels of melting in 2019 is a major concern. Five of the years with the greatest mass loss have now occurred in the past decade.
“What really matters is the trend,” said Dr Ruth Mottram, of the Danish Meteorological Institute in Copenhagen, who was not involved in the new study.
“And this trend, as shown by the Imbie project (ice sheet mass balance comparison exercise) and other work, helps track the high end of the projections.”
While 2020 has so far seen average conditions in Greenland, the overall impact of the massive ice losses seen in recent years could have major implications for people living in low lying areas of the world.
“The result for 2019 confirms that the ice sheet has returned to a state of high loss, in line with the IPCC’s worst-case global warming scenario,” said Professor Andy Shepherd of the University of Leeds, Imbie’s co-principal investigator .
“This means we need to prepare for about an additional 10cm of global sea level rise by 2100 from Greenland alone.”
“And at the same time, we have to invent a new worst-case scenario of global warming, because Greenland is already following the current one.”
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Getty Images
“If Greenland’s ice losses continue on their current course, an additional 25 million people could be inundated each year by the end of this century.”
Recent media reports have suggested that Greenland may have passed a point of no return, that the level of global warming the world has already committed to because of carbon emissions means all of Greenland will melt.
Dr Sasgen says that perspective may be correct – but the fate of Greenland is still in our hands.
“The sea level rise rates that we expect from Greenland and the risk of sudden sea level rise from Greenland are greatly reduced if we stay below warming limits,” he said. .
“The take-home message is that if we reduce CO2, and we reduce or limit global warming, the risk of Greenland’s huge contributions in the near future will also be reduced.”
The article was published in the journal Nature Communications Earth & Environment.
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