Greenland’s ice sheet is in the poorest state it's been in for millennia, and the worst is still to come. New research suggests the Greenland ice sheet is on track to lose ice faster than at any point in the last 12,000 years, even if the planet manages to achieve its most optimistic climate change targets.
Reported in the journal Nature this week, scientists led by the University at Buffalo put the modern decline of the ice sheet in southwestern Greenland in historical context using real-world measurements and reconstruction of the ice sheet’s ancient boundaries to work out a rate of loss, and how that compares historically.
“It is no secret that the Greenland Ice Sheet is in rough shape and is losing ice at an increasing rate,” Jason Briner, a geology professor at the University at Buffalo and lead author of the new study, said in a statement. “I think this is the first time that the current health of the Greenland Ice Sheet has been robustly placed into a long-term context.”
The findings show the melting rates in the first two decades of this century (2000 to 2018) equates to losing roughly 6,100 billion tonnes of ice per century. This is a rate higher than at any point during the past 12,000 years (since the last Ice Age), the highest point of which saw around 6,000 billion tonnes of ice loss per century during a freakishly warm period 10,000 and 7,000 years ago.
Based on how successfully the world curbs greenhouse gas emissions, the researchers argue the projected mass losses for the rest of this century are in the range of 8,800 to 35,900 billion tonnes. Clearly, this relentless ice loss is will have a serious impact on global sea-level rise. According to their workings, melting to this degree would result in a 2.4 to 9.9-centimeter sea-level rise, respectively.
“If the world goes on a massive energy diet, in line with a scenario that the Intergovernmental Panel on Climate Change calls RCP2.6, our model predicts that the Greenland Ice Sheet’s rate of mass loss this century will be only slightly higher than anything experienced in the past 12,000 years,” Briner said. “But, more worrisome, is that under a high-emissions RCP8.5 scenario — the one the Greenland Ice Sheet is now following — the rate of mass loss could be about four times the highest values experienced under natural climate variability over the past 12,000 years.”
This new research is the latest in a long line of recent studies that have shown the Greenland Ice Sheet is in a very sorry state. A study last year found Greenland is losing ice seven times faster than just 30 years ago. Last summer it lost 2 billion tons of ice in a single day. A study in August this year concluded that Greenland's ice sheet has passed the point of no return from decades of warming and thawing, suggesting the ice sheet will continue shrinking even if climate change was hypothetically stopped today.