Greenland ice sheet loss already
'unprecedented' and set to accelerate
ABC Science
By environment reporter Nick Kilvert
Posted 31 minutes ago
https://www.abc.net.au/news/science/2020-10-01/12705230Melting of the Greenland ice sheet has hit a rate unmatched in the last 12,000 years and is accelerating, scientists have confirmed.
Key points:
Worst-case predictions say Greenland will be melting 600 per cent faster than its present rate by the end of the century
That alone could add around 30 centimetres to sea levels, without accounting for Antarctic melting
Cutting our emissions rapidly buys us time to adapt to rising sea levels
Research published in Nature today predicts that the Greenland ice sheet will be melting by as much as six times its current rate by the end of the century if we don't get emissions down.
On the flipside, if we can achieve the best-case emissions reduction scenario forecast by the IPCC we can limit its increasing melt rate to around 40 per cent greater than its present rate.
A graphic showing the results of the study.
This graphic shows the rate of melting under the best and worst-case emissions scenarios (right).(Supplied: Jason Briner)
As the earth emerged from the last Ice Age around 11,000 years ago, the Arctic experienced a warm period or thermal maximum between about 10,000 and 7,000 years before present.
Researchers presumed that the rate of melting of the Greenland ice sheet in that period was higher than it is today.
Instead, they found that over the last 20 years, the southwestern Greenland ice sheet where this research was focussed, has been losing ice at an rate of about 6,100 billion tonnes per century on average — around 100 billion tonnes more than at its previous historical peak, according to author Jason Briner from the University of Buffalo.
"Our results suggest that yes, this century we will experience ice-loss rates not just similar to those in the past but exceeding those of the past, even under strict carbon emissions scenarios," Professor Briner said.
Worst-case scenario would see 600% increase in melting this century.