'Canary in the coal mine': Greenland ice has shrunk beyond return, study finds

Greenland's ice sheet may have shrunkpast the point of return, with the ice likely to melt away nomatter how quickly the world reduces climate-warming emissions,new research suggests.

Scientists studied data on 234 glaciers across the Arcticterritory spanning 34 years through 2018 and found that annualsnowfall was no longer enough to replenish glaciers of the snowand ice being lost to summertime melting.

That melting is already causing global seas to rise about amillimetreon average per year. If all of Greenland's ice goes,the water released would push sea levels up by an average of six metres enough to swamp many coastal cities around the world.This process, however, would take decades.

"Greenland is going to be the canary in the coal mine, andthe canary is already pretty much dead at this point," saidglaciologist Ian HowatofOhio State University. He and hiscolleagues published the study Thursday in the journal Communications Earth & Environment.

The Arctic has been warming at least twice as fast as therest of the world for the last 30 years, an observation referredto as Arctic amplification. The polar sea ice hit its lowestextent for July in 40 years.

The Arctic thaw has brought more water to the region,opening up routes for shipping traffic, as well as increasedinterest in extracting fossil fuels and other natural resources.

Greenland is strategically important for the U.S. militaryand its ballistic missile early warning system, as the shortestroute from Europe to North America goes via the Arctic island.

Last year, U.S. President Donald Trump offered to buy Greenland,an autonomous Danish territory. But Denmark, a U.S. ally,rebuffed the offer. Then last month, the U.S. reopened aconsulate in the territory's capital of Nuuk, and Denmarkreportedly said last week it was appointing an intermediarybetween Nuuk and Copenhagen some 3,500 kilometres away.

Scientists, however, have long worried about Greenland'sfate, given the amount of water locked into the ice.

The new study suggests the territory's ice sheet will nowgain mass only once every 100 years a grim indicator of howdifficult it is to regrow glaciers once they hemorrhage ice.

In studying satellite images of the glaciers, theresearchers noted that theyhad a 50 per centchance ofregaining mass before 2000, with the odds declining since.

"We are still draining more ice now than what was gainedthrough snow accumulation in 'good' years," said lead authorMichalea King, a glaciologist at Ohio State University.

The sobering findings should spur governments to prepare forsea-level rise, King said.

"Things that happen in the polar regions don't stay in thepolar region."

The world can still bring down emissions to slowclimate change, scientists said. Even if Greenland can't regainthe icy bulk that covered its two million square kilometres,containing the global temperature rise can slow the rate of iceloss.

"When we think about climate action, we're not talking aboutbuilding back the Greenland ice sheet," said Twila Moon, aglaciologist at the National Snow and Ice Data Center, in Boulder, Colo., who wasnot involved in the study.

"We're talking about how quicklyrapid sea-level rise comes to our communities, ourinfrastructure, our homes, our military bases."