Nearly 40 years of satellites data from Greeland shows the effects of global warming and climate change have caused irreparable damage to the ice sheet. According to a study published in Nature Communications Earth and Environment, even if global warming was stopped today, the Greenland ice sheet would continue to shrink. The dire findings suggest Greenland’s glaciers can no longer replenish the ice flowing into the oceans.
PhD candidate Michalea King, lead author of the study and a researcher at The Ohio State University’s Byrd Polar and Climate Research Center, said: “We’ve been looking at these remote sensing observations to study how ice discharge and accumulation have varied.
“And what we’ve found is that the ice that’s discharging into the ocean is far surpassing the snow that’s accumulating on the surface of the ice sheet.”
The Greenland ice sheet is a vast body of frozen land that, according to some estimates, is melting six times faster now than in the 1990s.
According to the National Snow and Ice Data Center (NSDIC), snowfall contribution to the ice sheet was slightly below average this year.
The update, posted on July 1, reads: “Spring melting over Greeland was near the long-term average, and concentrated along the southern coast, where extent was slightly above average.
“Although snowfall contribution to the ice sheet was below average early in the year, a significant snowfall event in early to mid-June brought the ice sheet close to balance, delaying the rapid early surface mass loss seen in recent years.
“A large melt event began on June 21, 2020, which will be discussed in a future post.”
Ms King and fellow researchers analysed monthly satellite data from more than 200 large glaciers melting into the surrounding oceans.
Ice that’s discharging into the ocean is far surpassing the snow that’s accumulating
Michalea King, Ohio State University
The observations found how much ice is breaking off from glaciers or flowing into the oceans.
The researchers found between the 1980s and 1990s, the amount of ice lost and replenished was mostly in balance.
In this timeframe, the ice sheet lost approximately 450 billion tons of ice each year, which was replaced with snowfall.
Ms King said: “We are measuring the pulse of the ice sheet—how much ice glaciers drain at the edges of the ice sheet—which increases in the summer.
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“And what we see is that it was relatively steady until a big increase in ice discharging to the ocean during a short five to six-year period.”
This so-called pulse is the amount of ice being lost each year.
Since about the year 2000, the pulse has been on the rise.
The pulse rose to about 500 billion tons of ice each year but, at the same time, snowfall did not increase.
And in the last decade, the rate of ice loss has remained roughly the same, meaning Greenland has been losing ice faster than it is being replenished.
Ms King said: “Glaciers have been sensitive to season melt for as long as we’ve been able to observe it, with spikes in ice discharge in the summer.
“But starting in 2000, you start superimposing that seasonal melt on a higher baseline – seasonal melt on a higher baseline – so you’re going to get even more losses.”
Before the year 2000, the ice sheet would have had the same chance to gain or lose mass each year.
Now, Greenland is predicted to only gain mass in one out of every 100 years.
Unfortunately, even if global climate conditions were to improve, scientists fear the melt will continue.
Ian Howat, study co-author, said: “Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss.
“Even if the climate were to stay the same or even get a little colder, the ice sheet would still be losing mass.”
The melting ice is expected to contribute to rising sea levels with last year’s melt adding about 2.2mm to the world’s oceans in just two months.
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