Search Results for Tag: Sea level
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climate scientist Stefan Rahmstorf of the Potsdam Institute for Climate Impact research has just quoted an as yet unpublished paper by colleagues, currently being reviewed, indicating that the temperature threshold for a melting of the Greenland ice sheet could be as low as 1.3 to 2.3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
Wild about the Antarctic?
I’m back! And as is so often the case, there’s a lot waiting to be done that didn’t disappear while I was on holiday. So for today,I’d like to draw your attention to some people who have been looking after the icy regions of the planet while the ice-blogger was still on holiday.
IUCN and WWF jointly produce a podcast called Wild Talk.
In the latest edition, one of the topics is the 50th anniversary of the Antarctic Treaty. There’s an interview with Carl Gustav Lundin
head of the IUCN Global Marine Programme about the Treaty and the state of the Antarctic today. Worth a listen.
Ministers from the Arctic Council and the Antarctic Treaty states held their first ever joint meeting in Washington on April 6 celebrating the 50th Anniversary of the signing of the Antarctic Treaty. WWF provided the ministers with recent evidence from both the north and south poles that clearly demonstrates global temperature increases must be kept well under two degrees Celsius.
“A global average temperature rise of 2 degrees is clearly too much for the poles,” says Rob Nicoll, Manager of WWF’s Antarctic and Southern Oceans Initiative. “Scientists are already unpleasantly surprised at how quickly the impacts of warming such as sea ice loss are showing up in the polar regions, exceeding recent predictions.”
Global average warming due to climate change since the late 1800s is showing severe impacts at less than one degree, as the Arctic is warming at about twice the global average and parts of the Antarctic are also outstripping the global average. The polar regions themselves have profound and not yet fully understood impacts on climate globally, and there are fears that polar tipping points could trigger abrupt change around the world.
A forthcoming report on Antarctic Climate Change and the Environment from the Scientific Committee on Antarctic Research is expected to up previous estimates on Antarctica’s expected substantial contributions to sea level rises. Marine food chains of global significance are also under threat from warming in the Antarctic.
DateApril 15, 2009 | 2:35 pm