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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climate scientist Stefan Rahmstorf of the Potsdam Institute for Climate Impact research has just quoted an as yet unpublished paper by colleagues, currently being reviewed, indicating that the temperature threshold for a melting of the Greenland ice sheet could be as low as 1.3 to 2.3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.

Date

January 26, 2011 | 9:30 am

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Arctic Science and Politics


It was a full house all day here in the world’s northernmost university.
The first two days are designated the “political” section, Wednesday to Friday will be the “science” section. Of course there has to be some overlap, with the scientific background for the politicians and the political considerations giving context to the scientists.
At lunchtime I talked to some scientists from North America and Europe attending the whole week. They seemed to have the feeling the political discussions were only skimming the surface. Some of them also said – and I’ve heard this a number of times before at conferences like this – it was a real pity the politicians didn’t stay around to engage with the scientists. There seems to be a consensus though that it is a good idea to bring scientists and the politicians who have the responsibility to decide on action taken based on scientific research – and to fund research – together more often.
US Rear Admiral Dave Titley had an interesting interpretation of the “tipping point” theme. “Melting sea ice in the Polar Ocean – a tipping point for US politics in the Arctic” was his presentation. He was stressing the Arctic is “tipping” into the mainstream, i.e. no longer a remote area, but one where shipping and oil and gas extraction would be on the increase from 2030 onwards, with a whole month ice-free every summer. He made no bones about the fact that the ice is melting fast and we need progress on a “polar code” and search-and-rescue procedures. He says it’s just a matter of luck that there has been no major cruise ship disaster so far, in what will remain dangerous waters.
In between times I talked to a Norwegian and two Russian “explorers”, who know all about that, the ones who took ships through the northern sea passages just last year. Things are really changing fast up here. That brings us back to the tipping points.
Spanish marine ecology professor Carlos Duarte was the “scientist amongst the politicians”. And he painted a worrying picture. 6 out of 14 “tipping elements” in the earth system, he says, are located in the Arctic. Let me close with a quick list of the dangerous factors he described: sea ice and albedo, the Greenland ice sheet, sea level rise, thermokarst and permaforost melting, increased freshwater runoff, methane hydrate release, pollutant release, ocean reversal to a CO2 source, boreal forest dieback and peat fires. While the Greenland ice cap melting and sea level increase are likely to be very long-term factors, the others could all be acting within decades, he says, and “tipping over” like dominos. He told me in an interview that he is really concerned with the paradox involved in exploiting even more fossil fuels which will further increase global warming and bring the “points of no return” closer, faster. He feels we are not far away from the “tipping point” represented by melting Arctic sea ice.He thinks the politicians have to abandon their reluctance to take unilateral steps and get moving.

Date

January 25, 2011 | 11:46 am

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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.

Date

January 20, 2011 | 3:19 pm

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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

Date

October 15, 2010 | 12:39 pm

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Alarming rise in Arctic methane emissions

Sound familiar? Ice-blog readers will remember methane is more than 20 times as powerful as CO2 as a greenhouse gas, and that scientists in the Arctic are measuring the extent of methane emissions from melting permafrost.
There are billions of tonnes of methane captured in the Arctic soil. As temperatures rise and the permafrost melts, more methane is released. It increases the greenhouse effect further, resulting in a “feedback loop”, with the increased warming melting more permafrost and releasing even more methane.
Zackenberg station in Greenland, which I visited this year, is one of the Arctic stations measuring methane. If you haven’t heard the programme I made including interviews with Prof. Morten Rasch, who heads the Greenland environment monitoring programme, it’s available under the “climate” banner on the right of DW’s environment page. There’s also a photo gallery with brief texts if you don’t have the time to listen to the full feature.
Climate Monitoring in Arctic Greenland
Now a study presented in the journal Nature reports a massive rise in the amount of methane being released from the Arctic permafrost.
See also today’s edition of the Guardian.
Guardian’s David Adam on rise in Arctic methane emissions
Although only 2% of global methane comes from the Arctic, the increase is highest in the Arctic, which is warming much faster than the rest of the planet.
The Guardian quotes Prof. Paul Palmer from Edinburgh University as saying the study “does not show the Arctic has passed a tipping point, but it should open people’s eyes. it shows there is a positive feedback and that higher temperatures bring higher emissions and faster warming”.
Edinburgh Climate Expert Paul Palmer

Date

January 15, 2010 | 8:57 am

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