Search Results for Tag: Sea level
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
On the Greenland Ice Sheet
I have been walking on the world’s 2nd largest ice sheet. It would take 30 days to cross it on foot and skis, and it’s almost 3 kilometres thick at its thickest point. It’s hard to imagine that much ice. And to imagine what it would mean for the world’s oceans if it melted. A disastrous 7m rise is the most common estimate, and views on whether or when that might happen vary widely. It’s a complex process, with a lot of uncertainty. But the Greenland ice cap is undoubtedly losing mass overall. And the IPCC predictions have been well overtaken by the current rate of global change.
I drove to the inland ice from Kangerlussaq in a four-wheel drive vehicle. The road was actually financed by the German car company Volkswagen. They decided around 1999 to build a test area for their vehicles on the ice, and this was the access road. (Seems surprising to get permission to build a car test track across the ice sheet in the national park, but there you are).VW stopped in 2005, so did maintenance it seems. Still, with that and the old US base, people have been telling me this area has the most roads in Greenland.
It’s a gravel and sandy track, but 2 hours take you out to the ice and there are spectacular views on the way.(Also muskox and reindeer, but that’s not our subject today).
This is a view on the approach.
It’s strange – the sudden contrast, how Greenland changes from being literally green to icy blue-white:
A wall of ice.
At the end of the track, we walked up the morane, gravel discarded by the ice, and down the other side to get onto the ice sheet. It’s now 40 metres lower than it was when the road was built.
Once on the ice sheet, it’s ice as far as the eye can see.
It’s no wonder this is becoming a tourist attraction, although the remoteness of northern Greenland and the trouble and expense of getting here make sure it’s not a destination for mass tourism. But all the guides and tourist people I’ve spoken to confirm that the talk about climate change is attracting more people.
Some say it’s just that people are becoming more aware of the beauties of the Arctic. One guide was convinced a lot of visitors want to see the ice before it dwindles or disappears. It would certainly take a lot to melt this one. But the process appears to be in motion.
DateJuly 28, 2009 | 10:41 am
“A huge leap for the G8, a small step for the climate?”
I have mixed feelings about what has been happening at the G8 summit. On the one hand, agreeing on the 2 degree limit and including the key players India and China is definitely positive and a step in the right direction. But it comes very late – and we still don’t know how we’re actually going to get there.
WWF’s climate and energy chief Regine Günther came out with the adaptation of the Neil Armstrong quote I’ve used in the title. An 80% reduction of greenhouse gas emissions by 2050 is all very well, she says, but there’s still ambiguity about the reference year and no clear 2020 goal.
Of course we know this is especially to accommodate US President Barack Obama. He wants more time to get regenerative energy in place and do a bit more PR at home. By comparison with the bad ol’ Bush years, we have to be thankful the new administration has finally brought the US on board the climate ship. But time is running out.
According to the EU, to keep the temperature rise to a maximum 2°C (which would already have disastrous consequences for people in some areas of the globe), emissions would have to peak by 2020 and be halved by 2050 as against 1990 levels.
The Arctic sea ice is melting – decreasing in surface area and thickness – at an alarming rate. (Well it alarms a lot of us, anyway).
The Greenland Ice Sheet – the largest body of freshwater ice in the northern hemisphere – is losing mass. Leading ice scientist Dorthe Dahl-Jensen describes the ice sheet as the “awakening giant”. Increased melting and ice discharge would have major consequences for global sea level. Greenland is a key area in the global climate process. The warming climate is also already having a considerable impact on the lifestyle of the people of Greenland.
And that is why I’ll be spending the next 3 weeks travelling in Greenland, interviewing scientists and locals about what’s happening to the climate there, how we measure this and likely consequences for the population of Greenland and the areas of the world whose coastal areas are likely to “go under”.
DateJuly 9, 2009 | 1:59 pm