Permafrost “tipping point” in less than 20 years?
I have been concerned about the effect of melting permafrost on the climate for quite some time, not least in the wake of encounters with scientists working in Greenland (this picture is Zackenberg, Greenland, 2009) and Alaska. Now research results published by the National Snow and Ice Data Centre (NSDIC) in Boulder, Colorado are indicating that there could be a “tipping point” or a “starting point”, as Professor Kevin Schaefer prefers to call it, in less than 20 years. That means a point when the vast areas of permafrost in Alaska, Canada, Siberia and parts of Europe go from being a “carbon sink” to a carbon source. The study indicates as much as two-thirds of the carbon frozen into the permafrost could be released.
There’s more info on the NSIDC website and on the ips news website, based on an interview with Prof. Schaefer. Not happy reading, but without big reductions in emissions, it will probably be impossible to prevent this. On top of that come the methane emissions, not included in the study. Methane is much more powerful than CO2 as a greenhouse gas.
DateFebruary 18, 2011 | 3:12 pm
On the trail of the truth about Greenland
Running for campus…
Let me recommend you a website and the book it’s based on.I’ve seen it here and it’s very impressive:Arctic Tipping Points
is the title, and it contains some beautiful and in some cases moving images relating to climate change and the Arctic. The editors are Carlos Duarte (quoted in earlier post) and Paul Wassmann (University of Tromsö.
(No tipping point for these swings)
I have been following the presentations dealing with the Greenland ice sheet closely. Sometimes it is a little frustrating when speakers hint at important results of studies which they cannot reveal fully ahead of publication. If you guys are trying to increase the suspense and arouse my interest in reports coming out in the next few months – you have succeeded. On the other hand, it seems a pity, with quite a few journalists sitting in the conference, that we can’t use the opportunity to pass on some interesting results. Unfortunate timing, it seems some of the reports were originally planned to have been ready. But let me sum up what I can here.
Peter Wadhams, Professor of Ocean Physics at the University of Cambridge introduced the strain of the conference dedicated to “ice-ocean-atmosphere interactions in the Arctic”. He refered to very large changes on the Greenland ice sheet, with very large areas of melt occurring in summer and a substantial net flux of fresh water into the sea every year. Now that is one of the key factors in measuring the changes. He told us the amount was almost the same as the total melt from mountain glaciers, suggesting this could be making a comparable contribution to global sea level rise as melt from all the rest of the glaciers in the world put together. He stressed the rate of melt on Greenland is accelerating and scientists just don’t know how the acceleration rate will continue.
Lars Otto Reiersen is the Executive Secretary for AMAP, the Arctic Monitoring and Assessment Programme. He reported on the SWiPA (Project) (Snow, Water, Ice and Permafrost in the Arctic), which is preparing a report to be presented to a meeting of Arctic ministers in May. (sigh!) Suffice it to say, he indicated that when it comes to the mass balance of the Greenland ice sheet, the updated figures will show even higher melt. All will be revealed in a few months, it seems. And it will not be cheery reading.
Late afternoon impression of Tromsö campus while the weather was still beautiful (some like it cold). It is thawing at the moment, but forecast to cool again soon.
DateJanuary 27, 2011 | 3:55 pm
Greenland ice sheet to melt at lower temperature than anticipated?
I am sitting in the opening session of the science section of the Arctic Frontiers conference gathering scientists and experts from around the world in the Norwegian Arctic town of Tromsö. Leading German climate scientist Stefan Rahmstorf of the Potsdam Institute for Climate Impact research has just quoted an as yet unpublished paper by colleagues, currently being reviewed, indicating that the temperature threshold for a melting of the Greenland ice sheet could be as low as 1.3 to 2.3 degrees C. The IPCC assessment assumes a temperature rise of 1.9 to 4.6 degrees C. as the critical threshold.
The Cancun agreement to limit warming to 2 degrees was based on IPCC figures. There is however an agreement on the need to review the scientific basis for the maximum temperature rise limit.
Given the huge significance of the Greenland ice sheet – a complete melting of the Greenland ice sheet could mean a rise in sea level of 7 metres- this would be a very significant new study, assuming it is reviewed positively. He expects it to be published in a month or two. Rahmstorf does not want to say any more, as it is not his paper and the authors are not present. But he is not the sort of scientist who quotes studies without careful consideration. He says he\’s glad the Cancun conference agreed to keep reviewing the science that provides the basis for setting the temperature limits.
DateJanuary 26, 2011 | 9:30 am
Alarming news on Greenland ice sheet
I was just preparing material for my trip to the Arctic Frontiers conference in Tromso this coming weekend when a press release came in headlined “new melt record for Greenland ice sheet”.
A study sponsored by WWF Arctic, the US National Science Foundation and NASA has been examining surface temperature anomalies over the Greenland ice sheet surface and estimates of surface melting from satellite data, observations on the ground and models. Dr Marco Tedesco, Director of the CryosphereProcesses Laboratory at the City College of New York , is quoted as saying the past melt season was exceptional, “with melting in some areas stretching up to 50 days longer than average”. It seems melting in 2010 started exceptionally early – at the end of April – and ended quite late in mid-September, says Tedesco. Amongst the other results of an article just published by Tedesco and others in Environmental Research Letters are that summer temperatures were up to 3 degrees C above the average in 2010, combined with reduced snowfall. Nuuk, the capital of Greenland, “had the warmest spring and summer since records began in 1873″.
The study indicates that bare ice was exposed earlier than the average and longer than previous years.
“Bare ice is much darker than snow and absorbs more solar radiation”, says Tedesco. “This means the old ice is warming, melting, and running off into the sea”.
Melting of the Greenland ice sheet is expected to be a major contributor to projected sea level rises in the future.
WWF’s climate specialist Dr. Martin Sommerkorn said sea level rise was expected to top one metre by 2100, largely because of melting from ice sheets.
All of this does not surprise me. I am intrigued to hear what the Arctic specialists will have to report at the Arctic Frontiers meeting – and what the politicians attending the political part of the forum will have to say.
DateJanuary 20, 2011 | 3:19 pm
Arctic research at Zackenberg this summer
Ice blog regulars will remember my trip to Zackenberg station last summer, in high Arctic Greenland.
(Zackenberg station summer 2009)
The ecological monitoring station has been manned for the past few summer months as usual.
I’d like to recommend a look at the blog from deputy station leader Lars Hansen.
(Lars in the field at Zackenberg summer 2009)
You will find some of his stories fascinating and his pictures are fantastic.The latest entry is all about a polar bear visiting the station on Lars’ birthday, October 7th, so very recently. Belated many happy returns Lars, you have some unusual party guests!
Blog from deputy station leader Lars Hansen
DateOctober 15, 2010 | 12:39 pm