ice sheets Greenland And Antarctica now it’s losing three times more annual ice than it was 30 years ago, according to a newly published international study. These great icy regions are melting, directly causes sea level riseas its ice goes from roosting on the mainland to entering the oceans as water.
Researchers using 50 different satellite data sources, Greenland’s melting has accelerated in recent years. Specifically, the average annual ice loss in Greenland from 2017 to 2020 was 20% higher than at the beginning of the decade and more than seven times the loss recorded in the early 1990s.
Greenland is losing seven times more ice a year than in the 1990s
New numbers “really pretty disastrous”Agrees co-author Ruth Mottram, a climate scientist at the Danish Meteorological Institute. “We’re losing more and more ice in Greenland.”
The study’s lead author, Ines Otosaka, a glaciologist at the University of Leeds in the United Kingdom, noted that this accelerated destruction of the ice sheet is clearly due to man-made climate change.
From 1992 to 1996 these two giant ice sheets (Antarctica and Greenland) Contains 99% of the world’s freshwater icereduced by 116,000 million tons per year.
But according to the research published in the journal, the amount of combined melt increased to 410 billion tons per year from 2017 to 2020, according to the most recent data available. Earth System Science Data.
“Unprecedented in current civilization”
“This is a devastating trend”Warned Twila Moon, assistant chief scientist at the US National Snow and Ice Center who was not part of the study. “These rates of ice loss are unprecedented in modern civilization.”
Since 1992, Earth has lost 8.3 trillion tons of ice to these two ice floes., the study highlights. That’s enough to fill the entire United States with about 3 feet of water, or to submerge France by about 50 feet.
But because the world’s oceans are so large, melting of the ice sheets since 1992 has only increased sea level by 21 millimeters on average. Across the planet, sea level rise is accelerating and The melting of these ice sheets was responsible for 5% of the rise in sea level, but now represents more than a quarter., according to research. The rest of the sea rise is due to the expansion of warmer waters and the melting of glaciers.
A team of over 65 scientists It regularly calculates the loss of ice floes in research funded by NASA and the European Space Agency, and the now-published study adds three more years of data. Otosaka said they used 17 different satellite missions and studied ice sheet melting using three different techniques, and all satellites, radar, ground observations and computer simulations basically say the same thing: the ice sheet over Greenland is melting and Antarctica is accelerating.
From 2017 to 2020, Greenland witnessed approximately 283 billion tons of ice melt per year, compared with a loss of 235 billion tons per year between 2012 and 2016.
The new figures also show that melting is slowing in parts of Antarctica, which has much more ice than Greenland. This is mostly due to smaller, shorter-term climate changes, Mottram said, but the overall long-term trend continues to show accelerating melting in Antarctica.
Antarctica is losing about 127 billion tons of ice a year from 2017 to 2020, 23% less than at the beginning of this decade, but 64% more overall than in the early 1990s.
Antarctica is losing 64% more ice per year than in the early 1990s
“As Greenland’s loss of ice mass surpasses that of Antarctica, there are problematic wild cards in the south, particularly the behavior of the Thwaites Glacier, nicknamed the Doomsday Glacier,” said Mark Serreze, director of the U.S. Snow and Ice Center.
“This is important because sea level rise will displace and/or economically affect hundreds, if not billions, of people“And it will likely cost billions of dollars,” said Waleed Abdalati, an ice researcher and former NASA chief scientist at the University of Colorado.
Study ‘not as surprising as disturbing’Abdalati said in an email. “A few decades ago it was assumed that these vast ice reservoirs were changing slowly, but using satellite observations, field observations and models, we observed that the ice was responding rapidly to climate change,” he added.
Reference work: https://essd.copernicus.org/articles/15/1597/2023/
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