Greenland ice cap experienced record mass loss in 2019, study finds

(Reuters) – The Greenland ice sheet lost a record amount of mass last year, according to a study released Thursday, a finding that could prompt scientists to redefine their worst-case scenario by assessing the effects of climate change.

The rate of ice loss had slowed for a two-year period amid cooler summers and heavier snowfall in West Greenland until 2018. But last year, as warm air flowed north from lower latitudes, the frozen island suffered a record loss of ice mass, said geoscientist and glaciologist Ingo Sasgen of the Alfred Wegener Institute in Germany.

This loss of 532 gigatons of ice – equivalent to about 66 tonnes of ice for every person on Earth – was 15% more than the previous record in 2012.

Of particular concern is the melting ice in Greenland, as the ancient ice cap contains enough water to raise the sea level by at least 6 meters if it were to melt completely.

The study adds to the evidence that Greenland’s ice mass is melting faster than expected amid global warming. Another study last week indicated that the island was no longer receiving enough annual snowfall to replace ice lost due to melting and calving on the edges of glaciers.

“We are probably on the way to an accelerated rise in sea level,” Sasgen told Reuters. “More melting of the ice sheet is not offset by periods when we have extreme snowfall.”

The study, published in the journal Communications Earth & Environment, used data collected by satellites on the gravitational force of the ice mass, which scientists can use to calculate how much snow and ice is trapped inside. .

Other research has shown that the melt is facilitated by the accumulation of water at the top of the ice and by the runoff of meltwater between the ice cap and the bedrock below.

These studies are helping scientists refine their projections of how climate change will impact the Arctic and how fast. Sasgen likened the process to thinking to difficult news from a doctor.

“It’s always depressing to see a new record,” Sasgen said.

But the studies do offer insight into “where the problem is, and you also know to some extent what the treatment is,” Sasgen added.

“It’s hard to say if these (weather) patterns will be the new normal, and which pattern will occur with how often,” Sasgen said.

The Arctic has already been warming at least twice as fast as the rest of the world over the past 30 years, as the amount of greenhouse gases accumulated in the atmosphere continues to increase. This warming also affected the Arctic sea ice, which declined to its lowest level in July in 40 years of record keeping.

As for the fate of Greenland, “I would say we are in a new normal for two decades of accelerating mass loss,” said Laura Andrews, a glaciologist at NASA’s Goddard Space Flight Center, not involved in the new study. “Greenland will continue to lose mass.”

If the rate of ice loss experienced in 2019 were to continue, the annual impact on sea level could lead to an increase in coastal flooding that affects up to 30 million more people each year by the turn of the century. said Andrew Shepherd, a polar scientist at the University. from Leeds which specializes in observing ice caps. Shepherd was not involved in the new search.

The new findings point out that “we need to prepare for a further 10 centimeters (4 inches) of global sea level rise by 2100 from Greenland alone,” Shepherd said. “We have to invent a new worst-case scenario of global warming, because Greenland is already following the current scenario.”