He Greenland thaw will cause a unprecedented sea level rise in the last 12,000 years, even if climate change is contained, according to a study published Wednesday in the journal Nature.
Research from the University of Buffalo and the University of Alaska Fairbanks, both in the US, is based on ice samples and mathematical models of increasing CO2 that have made it possible to reconstruct for the first time the history of the thaw during the entire Holocene, the geological epoch that began 11,700 years ago.
The report also concluded that if greenhouse gas emissions continue at the same rate, the ice sheet of several kilometers could be reduced by 36 trillion tons between 2000 and 2100, which would mean increase the level of the oceans by 10 cm.
Until the late 1990s, this huge ice sheet gained mass thanks to snowfall, and lost it in the summer with rising temperatures. But this balance was lost with the acceleration of climate change.
Sea level rise
Last year the layer lost more than 500,000 million tons, a record since the beginning of data collection by satellites, which contributed 40% to the rise in sea level in 2019.
And unless humanity radically cuts greenhouse gas emissions, that could be the “new normal,” said lead study author Jason Briner of the US University of Buffalo.
“Whatever the future CO2 emissions, the Greenland ice sheet will lose more mass during this century than during the warmest periods of the last 12,000 years,” he told AFP.
For their research, the scientists designed “high resolution simulations” from geological observations of the southwestern part of the Danish territory, spanning from the past 12,000 years to the year 2100.
“If the world were to apply a strict energy diet, in line with the scenario that the Intergovernmental Panel on Climate Change calls RCP2.6 (limited warming), our model predicts that the thaw rate this century would only be slightly higher than the recorded at any time in the past 12,000 years, “observes Briner.
However, in a “worrying scenario” of RCP8.5 emissions, which “currently follows” the Greenland ice cap, the rate of mass loss could be up to “four times higher” than that recorded “under climate variability. natural”.