Greenland's ice sheet lost 5.091 square kilometers of surface area between 1985 and 2022, according to a study published in the journal Nature. This is the first complete assessment of ice surface loss at that level.
That reduction in ice area includes 1.034 gigatons of ice that was lost as the glaciers retreated, along with the detachment of smaller pieces of ice from the edges of the glaciers.
The study is also the first to fully estimate how much ice Greenland has lost due to glacier retreat.
Miscalculations
The collected data indicate that previous estimates of changes in the Greenland Ice Sheet's mass balance – how much snow and ice accumulates each year versus how much is lost – underestimated those losses by as much as 20 percent, ignoring glacial retreat.
The lost 5.091 square kilometers represent the approximate area of the island nation of Trinidad and Tobago.
The study used more than 200.000 satellite images of the glacier's position and artificial intelligence to analyze changes over time.
"In Greenland, we have these areas around the edges where everything is kind of pulling back and collapsing," said study co-author Alex Gardner, a planet Earth expert at NASA's Jet Propulsion Laboratory.
"Previous methods were not as good at measuring that change in the ice sheet. But the change is huge," Gardner added.
Enough to raise the sea level
The Greenland ice sheet is one of only two such sheets left in the world – the other is in Antarctica. It consists of hundreds of glaciers and covers about 80 percent of Greenland's land mass.
If it were to melt completely, the Greenland ice sheet would raise global sea levels by about 7,4 meters.
With climate change warming the Arctic four times faster than the rest of the world, scientists say it is inevitable that the melting of the Greenland ice sheet will raise sea levels by at least 27 centimeters because of the warming that has already occurred.
The new estimate of ice loss from retreating glaciers would have little impact on global sea levels, scientists say, but a big impact on ocean circulation.
That much addition of fresh water to the salty ocean could strengthen coastal currents around Greenland and help weaken the Atlantic meridional circulation, which moves water from north to south and brings warmth to Europe.
