Glaciologist: “Sea level projections will need to be revised upward.”
The headline quote is over a month old, but, according to Google, it hasn’t been reprinted anywhere beyond the story on the official website of Denmark. That article opened:
New calculations show that the amount of melted inland ice in Greenland is 25-50% higher in 2010 than normally.
The big Arctic story this month has been NOAA’s 2010 Arctic Report Card, which found that, thanks to human-caused global warming, “Arctic of old is gone, experts warn,” as MNSBC put it. One NOAA scientist explained the importance of the Arctic as the canary in the coal mine: “Whatever is going to happen in the rest of the world happens first, and to the greatest extent, in the Arctic.”
But the rapid Arctic warming is important to our climate in its own right. It can directly alter our weather. It threatens to release vast quantities of carbon locked away in the previously frozen tundra (see Science stunner: Vast East Siberian Arctic Shelf methane stores destabilizing and venting: NSF issues world a wake-up call: “Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming”).
The rapid warming also threatens to accelerate sea level rise. The Report Card’s section on Greenland, written by an international team of experts, concludes:
Greenland climate in 2010 is marked by record-setting high air temperatures, ice loss by melting, and marine-terminating glacier area loss. Summer seasonal average (June-August) air temperatures around Greenland were 0.6 to 2.4°C above the 1971-2000 baseline and were highest in the west. A combination of a warm and dry 2009-2010 winter and the very warm summer resulted in the highest melt rate since at least 1958 and an area and duration of ice sheet melting that was above any previous year on record since at least 1978. The largest recorded glacier area loss observed in Greenland occurred this summer at Petermann Glacier, where 290 km2 of ice broke away. The rate of area loss in marine-terminating glaciers this year (419 km2) was 3.4 times that of the previous 8 years, when regular observations are available. There is now clear evidence that the ice area loss rate of the past decade (averaging 120 km2/year) is greater than loss rates pre-2000.
It should be no surprise that in the hottest year on record, we see the greatest ice loss in Greenland — see Nature: “Dynamic thinning of Greenland and Antarctic ice-sheet ocean margins is more sensitive, pervasive, enduring and important than previously realized.”
In Greenland, the warmth has meant accelerated flow of melt water from glaciers into the ocean, said Jason Box, a glaciologist at Ohio State University. As a result, he added, “sea level projections will need to be revised upward.“
And that brings me back to the Denmark story, which I only learned about because of an eagle-eyed hawk-eyed reader. I will reprint it in its entirety so it doesn’t disappear into the ether:
Meltdown in Greenland: inland ice drips away at record speedNew calculations show that the amount of melted inland ice in Greenland is 25-50% higher in 2010 than normallyNew calculations show that the amount of melting inland ice in Greenland is 25-50% higher in 2010 than normally, reports professional journal Ingeni¸ren (The Engineer). The Danish research scientist Sebastian Mernild of Los Alamos National Laboratory in the US told national daily newspaper Jyllands-Posten that his calculations show that 540 cubic kilometres of inland ice, weighing approx. 500 gigatons, have melted this summer, which is 25-50% more than in a typical year.
Mernild explained that the increased melting is mostly being caused by the rise in summer temperatures in Greenland seen over the last 10-12 years.
A recent study conducted by a US-Dutch research group has however shown that the melting is somewhat lower – “only” around 104 gigatons annually in the period 2002-2008.
Professor Dorthe Dahl-Jensen at the University of Copenhagen expresses slight scepticism, but does not reject Mernild’s calculations: “Although his figures look dramatic, I cannot deny that the melting has been so strong. It has been a very hot summer”.
Sebastian Mernild also told Jyllands-Posten that 52% of the inland ice has been melting this year. In 1972 it was only 17%.
According to Jyllands-Posten, climate researcher Jason E. Box from Byrd Polar Research Center at Ohio State University, USA, is also saying that the inland ice melting has been particular strong this year:
“It is my assessment that we have had the strongest melting since they started measuring the temperature in Greenland in 1873,” he said.
I can’t quite tell if the final quote is from Box or Jyllands-Posten. I’ll have to track down Box.
And yes, I am quite aware of that recent study suggesting Greenland didn’t lose ice prior to this year quite as fast as some recent analyses suggested (though, contrary to media reporting, it is still losing ice considerably faster than the IPCC ever thought likely). I have seen criticisms of that study from multiple Greenland experts and am holding off on posting on it until I talk to them.
The bottom line is that the Arctic is on a death spiral to a largely ice free condition in the next decade or two at most (see NSIDC director: “The volume of ice left in the Arctic likely reached the lowest ever level this month” and “Serreze: Arctic is “continuing down in a death spiral. Every bit of evidence we have says the ice is thinning”). And that would make both accelerate Arctic warming and make it increasingly difficult to preserve a livable climate for our children and countless future generations.
- M.I.T. doubles its 2095 warming projection to 10°F “” with 866 ppm and Arctic warming of 20°F
- Science: CO2 levels haven’t been this high for 15 million years, when it was 5° to 10°F warmer and seas were 75 to 120 feet higher “” “We have shown that this dramatic rise in sea level is associated with an increase in CO2 levels of about 100 ppm.”
- Sea levels may rise 3 times faster than IPCC estimated, could hit 6 feet by 2100