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| It is silly to say global warming is not taking place on a massive scale
The world already is experiencing major changes
Global warming no longer can be stopped
What has to be done now is to deal with a planet with ultra high speed winds sudden deserts large scale extreme weather events But there's still some ice about
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Wednesday, 3 September Major ice-shelf loss for Canada
The ice shelves in Canada's High Arctic have lost a colossal area this year, scientists report.
The floating tongues of ice attached to Ellesmere Island, which have lasted for thousands of years, have seen almost a quarter of their cover break away.
One of them, the 50 sq km (20 sq miles) Markham shelf, has completely broken off to become floating sea-ice.
Researchers say warm air temperatures and reduced sea-ice conditions in the region have assisted the break-up.
"These substantial calving events underscore the rapidity of changes taking place in the Arctic," said Trent University's Dr Derek Mueller.
"These changes are irreversible under the present climate." |
Satellite images show the loss of the Markham Ice Shelf over the last yearImage composite: BBC |
Scientists reported in July that substantial slabs of ice had calved from Ward Hunt Ice Shelf, the largest of the Ellesmere shelves.
Similar changes have been seen in the other four shelves.
As well as the complete breakaway of the Markham, the Serson shelf lost two sections totalling an estimated 122 sq km (47 sq miles), and the break-up of the Ward Hunt has continued.
Cold remnants
The shelves themselves are merely remnants of a much larger feature that was once bounded to Ellesmere Island and covered almost 10,000 sq km (3,500 sq miles).
Over the past 100 years, this expanse of ice has retreated by 90%, and at the start of this summer season covered just under 1,000 sq km (400 sq miles).
Much of the area was lost during a warm period in the 1930s and 1940s.
Temperatures in the Arctic are now even higher than they were then, and a period of renewed ice shelf break-up has ensued since 2002.
Unlike much of the floating sea-ice which comes and goes, the shelves contain ice that is up to 4,500 years old.
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A rapid sea-ice retreat is being experienced across the Arctic again this year, affecting both the ice attached to the coast and floating in the open ocean.
The floating sea-ice, which would normally keep the shelves hemmed in, has shrunk to just under five million sq km, the second lowest extent recorded since the era of satellite measurement began about 30 years ago.
"Reduced sea-ice conditions and unusually high air temperatures have facilitated the ice shelf losses this summer," said Dr Luke Copland from the University of Ottawa.
"And extensive new cracks across remaining parts of the Ward Hunt Ice Shelf mean that it will continue to disintegrate in the coming years."
Loss of ice in the Arctic, and in particular the extensive sea-ice, has global implications.
The "white parasol" at the top of the planet reflects energy from the Sun straight back out into space, helping to cool the Earth.
Further loss of Arctic ice will see radiation absorbed by darker seawater and snow-free land, potentially warming the Earth's climate at an even faster rate than current observational data indicates.
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'We could think of the Arctic as the refrigerator of the northern hemisphere climate system.
'What we're doing by getting rid of that sea ice is radically changing the nature of that refrigerator.
'We're making it much less efficient.
'But everything is connected together so what happens up there eventually influences what happens in other parts of the globe.' |
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Voyage into the Arctic as summer ice vanishes
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Marian Wilkinson, Environment Editor in the Arctic
THE vast Arctic sea ice which spreads across the North Pole could disappear during the summer within a decade or two — or even by 2013 — leading scientists are warning.
The Canadian Coast Guard's strongest icebreaker, the Louis S. St Laurent, took the Herald and an ABC Four Corners crew with a team of scientists going to the Arctic at the beginning of this summer's melt in July to explore the extraordinary changes there first hand.
Only a few years ago, climate modellers predicted the sea ice would not disappear in summer until at least the end of the century.
"Then they said 2070, and then they said 2050 and then they said 2030," said Robie Macdonald, a leading Canadian oceanographer on board the Louis.
August 4, 2008 |
"Not only do I see the change, but it's like they're moving the goalposts toward me and it's an amazing thing," he said.
The team on board the Louis are some of the thousands of scientists from 60 nations working to draw attention to the rapid changes in the Arctic and Antarctic during International Polar Year.
The icebreaker's route took us through thick sea ice at the entrance to the fabled Northwest Passage where over the centuries many navigators perished, most famously Sir John Franklin, a former governor of Tasmania.
Last year the Northwest Passage was virtually ice free for the first time in memory when the Arctic sea ice shrank to its lowest level since satellite observations began.
The US Interior Secretary, Dirk Kempthorne, announced in May the drastic loss of Arctic sea ice had forced him to list the polar bear as an endangered species because their populations could collapse within a few decades.
Hopes the sea ice would return to robust levels after last year's record low are unlikely to be realised, according to the latest figures from the US National Snow and Ice Data Centre.
While this year's melt is not expected to shatter last year's record, the sea ice is already significantly below average as the melt season peaks.
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"We might see an ice-free Arctic Ocean by the year 2030 — within some of our lifetimes," said Mark Serreze, a geographer at the snow and ice data centre.
"There are some scientists out there who think that even might be optimistic."
The loss of the sea ice in summer would be unprecedented in human history, said Don Perovich a geophysicist with the US Army's Cold Regions Research and Engineering Laboratory.
"As near as we can tell looking at the historical record, there's been ice in the Arctic in the summer for at least 16 million years," he said.
"There's a group that makes a very strong case that in 2012 or 2013 we'll have an ice-free [summer] Arctic — as soon as that.
It's astounding what's happened," said Dr Ted Scambos, a glaciologist from the snow and ice data centre.
The melt is leading Arctic nations, including Canada, Russia and the US, to seriously examine new shipping routes through the Arctic — including the Northwest Passage — and the potential expansion of huge oil and gas fields.
"As the ice recedes, it's opening up not only the Arctic passage but all the resources in the Arctic Ocean," said Scott Borgerson, from the US Council on Foreign Relations.
Last year's melt was produced by a "perfect storm" of natural weather patterns and rising temperatures in the Arctic caused by global warming.
The Arctic is warming at twice the average rate of the rest of the planet and the sea ice is considered by many scientists to be crucial for monitoring the speed of global climate change.
The more the bright white sea ice melts, the more the dark Arctic Ocean absorbs sunlight, in turn melting more sea ice and feeding back into global warming.
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The disappearance of the sea ice could have serious ramifications for the earth's climate and weather patterns, scientists say, explaining it would be like leaving the refrigerator door open on the planet.
"We could think of the Arctic as the refrigerator of the northern hemisphere climate system," Dr Serreze said.
"What we're doing by getting rid of that sea ice is radically changing the nature of that refrigerator.
"We're making it much less efficient.
"But everything is connected together so what happens up there eventually influences what happens in other parts of the globe."
Scientists are rapidly working to understand how much the loss of the summer sea ice might change weather patterns amid fears it will cause extreme storms and rainfall in some regions and prolong drought in others.
"The Arctic really can feed back into the global climate system," said Dr Macdonald, who has worked with the UN's peak scientific body, the Intergovernmental Panel on Climate Change.
"You know what happens when you get feedbacks — you get surprises and we don't like surprises."
The Louis' ice specialist, Erin Clark, explained that much of the ice at the entrance to the Northwest Passage this July was "first-year ice", frozen over just last year, and it would be prone to melting.
The extent of this year's melt will not be known until September and scientists are worried that with six weeks still left in the melt season, this thin first-year ice could be vulnerable to rapid loss.
"A race has developed between the waning sunlight and the weakened ice," the report of the national snow and ice data centre for the end of July explains.
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Despite a colder winter in parts of the Arctic and cooler temperatures in late July, the size of the sea ice is expected to shrink to levels close to the second or third lowest on record by September, according to the centre.
Researchers are trying to understand how much of the melting is due to the extreme natural variability in the northern polar climate system and how much is due to global warming caused by humans.
The Arctic Oscillation climate pattern, which plays a big part in the weather patterns in the northern hemisphere, has been in "positive" mode in recent decades bringing higher temperatures to the Arctic.
Dr Igor Polyakov, an oceanographer from the International Arctic Research Centre in Fairbanks, Alaska, explained that natural variability as well as global warming is crucial to understanding the ice melt.
"A combination of these two forces led to what we observe now and we should not ignore either forces" he said.
The consensus among scientists is that while the natural variability in the Arctic is an important contributor to climate change there, the climate models cannot explain the rapid loss of sea ice without including "human-induced" global warming.
This means human activity such as burning fossil fuels and land clearing which are releasing greenhouse gases in the atmosphere.
"There have been numerous models run that have looked at that and basically they can't reproduce the ice loss we've had with natural variability," said Dr Perovich. "You have to add a carbon dioxide warming component to it."
As the sea ice fails to recover, there are concerns it will become one of the "tipping points" pushing the planet to faster climate change.
A number of scientific papers are raising concerns that global warming, especially in the Arctic, will begin to thaw some of the vast areas of permafrost in the Arctic regions, especially in Siberia and Alaska.
If that happens infrastructure including roads, railways, bridges and pipelines could begin to collapse.
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More importantly, scientists say, it's possible that large amounts of the carbon dioxide and methane that are trapped in the permafrost will be released into the atmosphere, producing another feedback that will increase global warming.
The Arctic is a sentinel of change, Dr Macdonald explained on board the Louis, and urged everyone to take notice.
"We should care in the sense that what happens here is coming to us and sometimes, you know, a warning is a helpful thing to mobilise people," he said.
"If it takes the iconic polar bear for people to say maybe we need to do something, that's a good thing."
Copyright © 2008 The Sydney Morning Herald. |
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BBC — Wednesday, 18 June 2008 Arctic sea ice melt 'even faster'
By Richard Black
Environment correspondent, BBC News website
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Arctic sea ice is melting even faster than last year, despite a cold winter.
Data from the US National Snow and Ice Data Center (NSIDC) shows that the year began with ice covering a larger area than at the beginning of 2007.
But now it is down to levels seen last June, at the beginning of a summer that broke records for sea ice loss.
Scientists on the project say that much of the ice is so thin that it melts easily, and the Arctic may be ice-free in summer within five to 10 years.
"We had a bit more ice in the winter, although we were still way below the long-term average," said Julienne Stroeve from NSIDC in Boulder, Colorado.
"So we had a partial recovery. But the real issue is that most of the pack ice has become really thin, and if we have a regular summer now, it can just melt away," she told BBC News.
In March, Nasa reported that the area covered by sea ice was slightly larger than in 2007, but much of it consisted of thin floes that had formed during the previous winter.
These are much less robust than thicker, less saline floes that have already survived for several years.
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A few years ago, scientists were predicting ice-free Arctic summers by about 2080.
Then computer models started projecting earlier dates, around 2030 to 2050.
Then came the 2007 summer that saw Arctic sea ice shrink to the smallest extent ever recorded, down to 4.2 million sq km from 7.8 million sq km in 1980.
By the end of last year, one research group was forecasting ice-free summers by 2013.
"I think we're going to beat last year's record melt, though I'd love to be wrong," said Dr Stroeve.
"If we do, then I don't think 2013 is far off any more. If what we think is going to happen does happen, then it'll be within a decade anyway."
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Rising tide
Countries surrounding the Arctic are eyeing the economic opportunities that melting ice might bring.
Canada and Russia are exploring sovereignty claims over tracts of Arctic seafloor, while just this week US President George Bush has urged more oil exploration in US waters - which could point the way to exploitation of reserves off the Alaskan coast.
But from a climate point of view, the melt could bring global impacts accelerating the rate of warming and of sea level rise.
"This is a positive feedback process," commented Dr Ian Willis, from the Scott Polar Research Institute in Cambridge.
"Sea ice has a higher albedo (reflectivity) than ocean water; so as the ice melts, the water absorbs more of the Sun's energy and warms up more, and that in turn warms the atmosphere more - including the atmosphere over the Greenland ice sheet."
Greenland is already losing ice to the oceans, contributing to the gradual rise in sea levels.
The ice cap holds enough water to lift sea levels globally by about seven metres (22ft) if it all melted.
Natural climatic cycles such as the Arctic Oscillation play a role in year-to-year variations in ice cover.
But Julienne Stroeve believes the sea ice is now so thin that there is little chance of the melting trend turning round.
"If the ice were as thin as it was in the 1970s, last year's conditions would have brought a dip in cover, but nothing exceptional.
"But now it's so thin that you would have to have an exceptional sequence of cold winters and cold summers in order for it to rebuild."
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An arial view of the Quervain bay, Kalaallit Nunaat west coast (Greenland) |
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Wednesday, 12 December 2007
Arctic summers ice-free 'by 2013' By Jonathan Amos
Science reporter, BBC News, San Francisco
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Scientists in the US have presented one of the most dramatic forecasts yet for the disappearance of Arctic sea ice.
Their latest modelling studies indicate northern polar waters could be ice-free in summers within just 5-6 years.
Professor Wieslaw Maslowski told an American Geophysical Union meeting that previous projections had underestimated the processes now driving ice loss.
Summer melting this year reduced the ice cover to 4.13 million sq km, the smallest ever extent in modern times.
Remarkably, this stunning low point was not even incorporated into the model runs of Professor Maslowski and his team, which used data sets from 1979 to 2004 to constrain their future projections.
"Our projection of 2013 for the removal of ice in summer is not accounting for the last two minima, in 2005 and 2007," the researcher from the Naval Postgraduate School, Monterey, California, explained to the BBC.
"So given that fact, you can argue that may be our projection of 2013 is already too conservative."
Real world
Using supercomputers to crunch through possible future outcomes has become a standard part of climate science in recent years.
Professor Maslowski's group, which includes co-workers at Nasa and the Institute of Oceanology, Polish Academy of Sciences (PAS), is well known for producing modelled dates that are in advance of other teams.
These other teams have variously produced dates for an open summer ocean that, broadly speaking, go out from about 2040 to 2100.
But the Monterey researcher believes these models have seriously underestimated some key melting processes.
In particular, Professor Maslowski is adamant that models need to incorporate more realistic representations of the way warm water is moving into the Arctic basin from the Pacific and Atlantic oceans.
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"My claim is that the global climate models underestimate the amount of heat delivered to the sea ice by oceanic advection," Professor Maslowski said.
"The reason is that their low spatial resolution actually limits them from seeing important detailed factors.
"We use a high-resolution regional model for the Arctic Ocean and sea ice forced with realistic atmospheric data. This way, we get much more realistic forcing, from above by the atmosphere and from the bottom by the ocean."
The Intergovernmental Panel on Climate Change (IPCC), the UN-led body which assesses the state of the Earth's climate system, uses an averaged group of models to forecast ice loss in the Arctic.
But it is has become apparent in recent years that the real, observed rate of summer ice melting is now starting to run well ahead of the models.
The minimum ice extent reached in September 2007 shattered the previous record for ice withdrawal set in 2005, of 5.32 million square km.
The long-term average minimum, based on data from 1979 to 2000, is 6.74 million square km.
In comparison, 2007 was lower by 2.61 million square km, an area approximately equal to the size of Alaska and Texas combined, or the size of 10 United Kingdoms.
Diminishing returns
Professor Peter Wadhams from Cambridge University, UK, is an expert on Arctic ice.
He has used sonar data from military submarines to show that the speed at which the ice is thinning is higher than the rate at which it is losing area.
"Some models have not been taking proper account of the physical processes that go on," he commented.
"The ice is thinning faster than it is shrinking; and some modellers have been assuming the ice was a rather thick slab.
"Wieslaw's model is more efficient because it works with data and it takes account of processes that happen internally in the ice."
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He cited the ice-albedo feedback effect in which open water receives more solar radiation, which in turn leads to additional warming and further melting.
Professor Wadhams said the Arctic was now being set up for further ice loss in the coming years.
"The implication is that this is not a cycle, not just a fluctuation. The loss this year will precondition the ice for the same thing to happen again next year, only worse.
"There will be even more opening up, even more absorption and even more melting.
"In the end, it will just melt away quite suddenly. It might not be as early as 2013 but it will be soon, much earlier than 2040."
The US National Snow and Ice Data Center (NSIDC) collects the observational data on the extent of Arctic sea ice, delivering regular status bulletins.
Its research scientist Dr Mark Serreze was asked to give one of the main lectures here at this year's AGU Fall Meeting.
Discussing the possibility for an open Arctic ocean in summer months, he told the meeting: "A few years ago even I was thinking 2050, 2070, out beyond the year 2100, because that's what our models were telling us. But as we've seen, the models aren't fast enough right now; we are losing ice at a much more rapid rate.
"My thinking on this is that 2030 is not an unreasonable date to be thinking of, and yet Dr Maslowski has the view that it may be as early as 2013. He's on the record now. We'll see how that pans out."
Former US Vice President Al Gore cited Professor Maslowski's analysis on Monday in his acceptance speech at the Nobel Peace Prize ceremony in Oslo.
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The US NSIDC monitors Arctic sea ice extent on a five-day mean.
The 16 September 2007 record low falls below the previous minimum set on 20-21 September 2005, by an area roughly the size of Texas and California
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Sunday, 24 February 2008 Antarctic glaciers surge to ocean By Martin Redfern
Rothera Research Station, Antarctica
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UK scientists working in Antarctica have found some of the clearest evidence yet of instabilities in the ice of part of West Antarctica.
If the trend continues, they say, it could lead to a significant rise in global sea level.
The new evidence comes from a group of glaciers covering an area the size of Texas, in a remote and seldom visited part of West Antarctica.
The "rivers of ice" have surged sharply in speed towards the ocean.
David Vaughan, of the British Antarctic Survey, explained: "It has been called the weak underbelly of the West Antarctic Ice Sheet, and the reason for that is that this is the area where the bed beneath the ice sheet dips down steepest towards the interior.
"If there is a feedback mechanism to make the ice sheet unstable, it will be most unstable in this region."
There is good reason to be concerned.
Satellite measurements have shown that three huge glaciers here have been speeding up for more than a decade.
The biggest of the glaciers, the Pine Island Glacier, is causing the most concern.
Inhospitable conditions
Julian Scott has just returned from there.
He told the BBC: "This is a very important glacier; it's putting more ice into the sea than any other glacier in Antarctica.
"It's a couple of kilometres thick, its 30km wide and it's moving at 3.5km per year, so it's putting a lot of ice into the ocean."
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It is a very remote and inhospitable region.
It was visited briefly in 1961 by American scientists but no one had returned until this season when Julian Scott and Rob Bingham and colleagues from the British Antarctic survey spent 97 days camping on the flat, white ice.
At times, the temperature got down to minus 30C and strong winds made work impossible.
At one point, the scientists were confined to their tent continuously for eight days.
"The wind really makes the way you feel incredibly colder, so just motivating yourself to go out in the wind is a really big deal," Rob Bingham told BBC News.
When the weather improved, the researchers spent most of their time driving skidoos across the flat, featureless ice.
"We drove skidoos over it for something like 2,500km each and we didn't see a single piece of topography."
Long drag
Rob Bingham was towing a radar on a 100m-long line and detecting reflections from within the ice using a receiver another 100m behind that.
The signals are revealing ancient flow lines in the ice.
The hope is to reconstruct how it moved in the past.
Julian Scott was performing seismic studies, using pressurised hot water to drill holes 20m or so into the ice and place explosive charges in them.
He used arrays of geophones strung out across the ice to detect reflections, looking, among other things, for signs of soft sediments beneath the ice that might be lubricating its flow.
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He also placed recorders linked to the global positioning system (GPS) satellites on the ice to track the glacier's motion, recording its position every 10 seconds.
Throughout the 1990s, according to satellite measurements, the glacier was accelerating by around 1% a year.
Julian Scott's sensational finding this season is that it now seems to have accelerated by 7% in a single season, sending more and more ice into the ocean.
"The measurements from last season seem to show an incredible acceleration, a rate of up to 7%. That is far greater than the accelerations they were getting excited about in the 1990s."
The reason does not seem to be warming in the surrounding air.
One possible culprit could be a deep ocean current that is channelled onto the continental shelf close to the mouth of the glacier.
There is not much sea ice to protect it from the warm water, which seems to be undercutting the ice and lubricating its flow.
Ongoing monitoring
Julian Scott, however, thinks there may be other forces at work as well.
Much higher up the course of the glacier there is evidence of a volcano that erupted through the ice about 2,000 years ago and the whole region could be volcanically active, releasing geothermal heat to melt the base of the ice and help its slide towards the sea.
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David Vaughan believes that the risk of a major collapse of this section of the West Antarctic ice sheet should be taken seriously.
"There has been the expectation that this could be a vulnerable area," he said.
"Now we have the data to show that this is the area that is changing. So the two things coinciding are actually quite worrying."
The big question now is whether what has been recorded is an exceptional surge or whether it heralds a major collapse of the ice. Julian Scott hopes to find out.
"It is extraordinary and we've left a GPS there over winter to see if it is going to continue this trend."
If the glacier does continue to surge and discharge most of it ice into the sea, say the researchers, the Pine Island Glacier alone could raise global sea level by 25cm.
That might take decades or a century, but neighbouring glaciers are accelerating too and if the entire region were to lose its ice, the sea would rise by 1.5m worldwide.
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Antarctic Ice Shelves Melting Ice shelves act as huge conveyer belts taking the continent’s snow cover out to the surrounding seas |
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Published on Friday, October 5, 2007 by Inter Press Service
Climate Change and Entire Landscapes on the Move
The hot breath of global warming has now touched some of the coldest northern regions of world, turning the frozen landscape into mush as temperatures soar 15 degrees C. above normal.
by Stephen Leahy
Entire hillsides, sometimes more than a kilometre long, simply let go and slid like a vast green carpet into valleys and rivers on Melville Island in Canada’s northwest Arctic region of Nunavut this summer, says Scott Lamoureux of Queens University in Canada and leader of one the of International Polar Year projects.
“The entire landscape is on the move, it was very difficult to find any slopes that were unaltered,” said Lamoureux, who led a scientific expedition to the remote and uninhabited island.
The topography and ecology of Melville Island is rapidly being rearranged by climate change.
“Every day it looked different,” he told IPS. “This is a permanent change.”
Normally Melville Island’s 42,500 sq kms are locked in sea ice all year round, as it is part of the high region that has been relatively unaffected by the dramatic declines in Arctic sea ice over the past decade.
Until this year, that is.
This summer, southern parts of the island were free of sea ice, Lamoureux told IPS.
He has led expeditions to the island every year since 2003.
On land at Mould Bay on the island’s northwest side, his research team measured record-shattering temperatures of between 15 to 22 degrees C in July.
Until then, the normal July average temperature had been between 4 and 5 degrees C.
The extraordinary heat thawed the tundra permafrost — permanently frozen ground — to depths of more than a metre, he said.
At that depth, there is mostly ice and when it melts, it destabilises the thin, top layer of plants and soil that has patiently built up over thousands of years.
Enormous amounts of water and sediments are being discharged into rivers, lakes and oceans.
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Studies are underway to determine the impact on birds, fish, musk oxen and other creatures that live there in the summer.
Given the extent of the changes, there is little doubt there will be significant ecological impacts, he said.
The record low level of sea ice in the entire Arctic Ocean will also change regional and even global weather patterns.
Much more snow will fall in the Arctic due to the increased moisture from the increased amounts of open water.
All that water is also dark and heat-absorbing instead of sunlight-reflecting ice, so the region gets warmer, melting more ice in what is a strong positive feedback loop.
Other parts of the Arctic region have already changed dramatically in the past 50 years.
“There are trees and lawns in Nome (Alaska) now,” said Patricia Cochran, chair of the Inuit Circumpolar Council.
“I never thought I’d see trees growing on the tundra,” Cochran said about her hometown, which lies on the Bering Sea and was once too cold for trees to grow.
“Beavers are overrunning the area now that there is food for them. They are even in Barrow, north of the Arctic Circle,” she told IPS from her office in Anchorage.
The tundra is also melting, resulting in coffins disturbingly popping out of the ground in graveyards, roads crumbling and giant sink holes opening up everywhere, including in some towns, she said.
Every summer brings plants, animals, birds and insects that no one has seen before.
Dragonflies and turtles now roam the lands that had been too icy for tens of thousands of years.
“Everyone living here has seen the changes,” Cochran said.
And there are more changes to come even if politicians and corporate CEOs stop pretending to act and actually curb emissions of greenhouse gases.
“The Arctic Ocean will be ice free in the summer, it’s just a matter of how soon,” said Andrew Weaver, a climatologist at the School of Earth and Ocean Sciences in the University of Victoria, Canada.
A new study led by the U.S. National Aeronautics and Space Administration this week revealed that the Arctic’s thick, year-round sea ice cover declined 2.6 million square kilometres beyond the summer average minimum since satellites started measurements in 1979.
That’s about the size of the province of Ontario.
“That decline is nothing short of stunning,” Weaver told IPS.
It’s also a permanent decline because while the ice will re-form over the six-month-long winter when there is no sunlight, it will be much thinner and likely to melt quickly next summer, he said.
Because Arctic sea ice is floating, the melting will not affect sea levels but it will “wreak absolute havoc on Arctic ecosystems”.
The rapid meltdown is pushing the upper end of the climate experts’ projections, he said, noting that new research shows that change in the Arctic could happen abruptly.
In other words, the worst case scenarios and beyond may come to pass. They may even be on their way right now.
Oil and gas exploration may one day reach remote Meville Island if there’s a summer ice-free path because of the extensive natural gas and oil reserves there, said Lamoureux.
Burning such fossil fuels is the major reason why the Arctic is losing ice.
Scientists and native people note that it would be more than ironic should those emissions facilitate the extraction of even more fossil fuels with which to further warm our overheating global greenhouse.
© 2007 IPS - Inter Press Service |
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BBC — Friday, 21 September 2007 Ice withdrawal 'shatters record'
Arctic sea ice shrank to the smallest area on record this year, US scientists have confirmed.
The National Snow and Ice Data Center (NSIDC) said the minimum extent of 4.13 million sq km (1.59 million sq miles) was reached on 16 September.
The figure shatters all previous satellite surveys, including the previous record low of 5.32 million sq km measured in 2005.
Earlier this month, it was reported that the Northwest Passage was open.
The fabled Arctic shipping route from the Atlantic to the Pacific is normally ice-bound at some location throughout the year; but this year, ships have been able to complete an unimpeded navigation.
The statement
'Fast track'
Arctic sea ice loses area in summer months and regrows in the winter cold.
The researchers at NSIDC judge the ice extent on a five-day mean.
The minimum for 2007 falls below the minimum set on 20-21 September 2005 by an area roughly the size of Texas and California combined, or nearly five UKs.
Speaking to BBC News on Monday this week, Mark Serreze, a senior research scientist at the NSIDC, said: "2005 was the previous record and what happened then had really astounded us; we had never seen anything like that, having so little sea ice at the end of summer.
Then along comes 2007 and it has completely shattered that old record."
He added: "We're on strong spiral of decline; some would say a death spiral.
I wouldn't go that far but we're certainly on a fast track.
We know there is natural variability but the magnitude of change is too great to be caused by natural variability alone."
The team will now follow the progress of recovery over the winter months.
Modelled decline
In December 2006, a study by US researchers forecast that the Arctic could be ice-free in summers by 2040.
A team of scientists from the National Center for Atmospheric Research (NCAR), the University of Washington, and McGill University, found that "positive feedbacks" were likely to accelerate the decline of the region's ice system.
Sea ice has a bright surface which reflects 80% of the sunlight that strikes it back into space. However, as the ice melts during the summer, more of the dark ocean surface becomes exposed.
Rather than reflecting sunlight, the ocean absorbs 90% of it, causing the waters to warm and increase the rate of melting.
Scientists fear that this feedback mechanism will have major consequences for wildlife in the region, not least polar bears, which traverse ice floes in search of food.
On a global scale, the Earth would lose a major reflective surface and so absorb more solar energy, potentially accelerating climatic change across the world. |
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Climate change: The crack of doom?
RAYMOND HAINEY
ITS collapse was so violent that it was picked up by earthquake monitors 150 miles away — a thundering warning to the world that the Arctic was heating up faster than scientists had imagined.
A giant ice shelf, covering 41 square miles, had broken off from the Canadian mainland and floated off into the sea.
Yet for 16 months, experts were unaware that the Ayles ice shelf — just one of six remaining in the Canadian Arctic — had drifted off until a scientist began examining old satellite images.
Yesterday, scientists said the dramatic discovery capped a year of new studies, which have revealed that the world is heating up faster than had been thought.
From the slowing Gulf Stream, to the warmest British summer on record, to unusually warm water in the Caribbean, researchers have mapped our rapidly changing climate.
Scientists were yesterday still coming to terms with the importance of the Ayles ice shelf collapse.
"This is a dramatic and disturbing event," said Dr Warwick Vincent, an Arctic ice expert at Laval University in Quebec.
"It shows we are losing remarkable features of the Canadian North that have been in place for many thousands of years. We are crossing climate thresholds and these may signal the onset of accelerated change ahead."
Dr Vincent added that he had never seen such a dramatic loss of sea ice, a chunk the size of the Hebridean island of Rum or 11,000 football pitches, in a decade's study of the Arctic.
He said: "It is consistent with climate change. We're not able to connect all the dots, but unusually warm temperatures definitely played a major role."
The Canadian view was backed by Dr Ian Moffatt, a Stirling University climate-change expert, who warned that the Earth appeared to be warming faster than had been thought.
Dr Moffatt called for a massive international effort to develop new, green energy sources before it was too late.
Dr Moffatt said that the Intergovernmental Panel on Climate Change (IPCC) had predicted an increase of one to five deg C over the next 50 to 100 years, but it was beginning to appear that temperature change was at the upper end of the IPCC predictions.
"This ice loss is a serious problem, because it's indicating a bigger breakdown than was predicted," Dr Moffatt said.
But there are solutions, Dr Moffatt stressed: "The key feature is we start looking at alternative energy sources, rather than just talking about it."
Dr Moffatt said the cost of developing cleaner energy could be high, but not as high as once feared. And he warned: "If we don't pay these costs, it will cost us the Earth."
Extensive ice loss could also lead to the extinction of animals such as the polar bear, Dr Moffatt predicted.
And he said that global warming could plunge Scotland into a deep freeze, because huge amounts of fresh water trapped in ice could melt into the Atlantic and kill off the Gulf Stream, which passes past the UK and Ireland and keeps the land temperature up.
Dr Moffatt explained: "If we get a large quantity of ice going into the North Atlantic and it begins to melt, salinity is reduced, it cools the sea and turns off the great ocean currents.
"We could see Edinburgh, which is on the same latitude as Moscow, becoming very cold."
Duncan McLaren, the chief executive of Friends of the Earth Scotland, said the future of the planet looked bleak — but he pointed to rays of hope in 2006.
He said: "This year will go down as the year that the vast majority of people woke up to climate change. People are now seeing the reality of climate change."
THE HEAT IS ON AS ICE MELTS AND ISLANDS VANISH
GLOBAL problems attributed to climate change in 2006 include:
INDIA: Lohachara in the Bay of Bengal, submerged by rising sea levels, was the first inhabited island to be wiped out by global warming.
UK: Britain notched up its highest average temperature since records began in 1659.
EUROPE: The skiing industry in the Alps looks bleak after the warmest successive period for 500 years.
AFRICA: The Sahara desert continues to expand, turning farmland into sand and fuelling civil war in Darfur, Sudan.
US VIRGIN ISLANDS: The Caribbean island group lost nearly half the coral reefs in study sites.
GREENLAND: Glaciers are melting, with a 250 per cent loss of ice.
AUSTRALIA: The bushfire season is starting earlier and burning more fiercely.
©2005 Scotsman.com |
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"We Can't Say We Weren't Warned"
By Jean-Marcel Bouguereau Le Nouvel Observateur Wednesday 31 January 2007 [Images inserted by TheWE.cc]
What's happened?
Why this sudden keen interest in climatic phenomena?
I have to say that each of us has had an opportunity to become aware of the seriousness of the situation with the mood swings of a climate that's become erratic.
New bases for recent anguish
But the 500 delegates meeting in Paris under the aegis of the United Nations, the same ones whose first work had served as the foundation for the famous Kyoto Protocol, will - between now and Friday — give new bases for this recent anguish.
"Indefinite growth is impossible, we only have one Earth, but a civilization of happiness is possible.
Solutions exist, but public opinion ignores them, since the present power structures and those who wield economic and political power oppose those solutions."
That's what René Dumont, the first ecologist candidate for [French] president, said as early as 1974.
Preaching in the desert
While he was preaching in the desert then and only garnered a weak 1.3 percent of votes, thirty years later all the candidates are pushing one another to sign Nicolas Hulot's "ecological pact."
Suddenly, people are sounding the alarm everywhere.
Not without some hypocrisy.
Even George Bush mentions, thanks to new technologies, a "post-Kyoto strategy" — while he's refused to sign that protocol.
Davos!!!
And in Davos, the heads of companies have just salved their collective conscience by increasing the numbers of debates and roundtables on climate change.
But only 20 percent of them consider protection of the environment to be a priority.
Capitalism that can't allow itself
These company bosses know that the break with growth that the Rome Club advocated as far back as 1972 is a death sentence for a capitalism that can't allow itself a drastic reduction in production and material consumption.
It's a whole different economy that must be put into effect, based on other values.
And unless we confront that unknown, we are in the process of compromising the life of future generations.
The problem is that when they are questioned, the ardor of the French to act against global warming is as hypocritical as that of company bosses: 93 percent are ready to systematically sort their garbage or to decrease their electricity and water consumption, but that proportion falls to 61 percent when it comes to using the car less often.
We are running into a wall.
But no one can say we weren't warned.
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BBC — Friday, 14 September 2007 Warming 'opens Northwest Passage'
The most direct shipping route from Europe to Asia is fully clear of ice for the first time since records began, the European Space Agency (Esa) says.
Historically, the Northwest Passage linking the Atlantic and Pacific Oceans has been ice-bound through the year.
But the agency says ice cover has been steadily shrinking, and this summer's reduction has made the route navigable.
The findings, based on satellite images, raised concerns about the speed of global warming.
'Extreme'
The Northwest Passage is one of the most fabled sea routes in the world - a short cut from Europe to Asia through the Canadian Arctic.
Recent years have seen a marked shrinkage in its ice cover, but this year it was extreme, Esa says.
It says this made the passage "fully navigable" for the first time since monitoring began in 1978.
"We have seen the ice-covered area drop to just around 3m sq km (1.2m sq miles)," Leif Toudal Pedersen of the Danish National Space Centre said.
He said it was "about 1m sq km (386,000 sq miles) less than the previous minima of 2005 and 2006".
"There has been a reduction of the ice cover over the last 10 years of about 100, 000 sq km (38,600 sq miles) per year on average, so a drop of 1m sq km (386,000 sq miles) in just one year is extreme," Mr Pedersen said.
The Northeast Passage through the Russian Arctic has also seen its ice cover shrink and it currently "remains only partially blocked," Esa says.
'Battle for Arctic'
Scientists have linked the changes to global warming which may be progressing faster than expected.
The opening of the sea routes is already leading to international disputes.
Canada says it has full rights over those parts of the Northwest Passage that pass through its territory and that it can bar transit there.
But this has been disputed by the US and the European Union.
They argue that the new route should be an international strait that any vessel can use. |
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Greenland ice cap thickens slightly
Friday, October 21, 2005
The 9,842-feet thick ice cap is a key concern in debates about climate change because a total melt would raise world sea levels by about 7 meters. And a runaway thaw might slow the Gulf Stream that keeps the North Atlantic region warm.
But satellite measurements showed that more snowfall was falling and thickening the ice cap, especially at high altitudes, according to the report in the journal Science.
Glaciers at sea level have been retreating fast because of a warming climate, making many other scientists believe the entire ice cap was thinning.
"The overall ice thickness changes are ... approximately plus 1.9 inches a year or 21.26 inches over 11 years," according to the experts at Norwegian, Russian and U.S. institutes led by Ola Johannessen at the Mohn Sverdrup center for Global Ocean Studies and Operational Oceanography in Norway.
However, they said that the thickening seemed consistent with theories of global warming, blamed by most experts on a build-up of heat-trapping gases from burning fossil fuels in power plants, factories and cars.
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Warmer air, even if it is still below freezing, can carry more moisture. That extra moisture falls as snow below 32 Fahrenheit.
Satellite data not good enough to measure melt nearer sea level
And the scientists said that the thickening of the ice-cap might be offset by a melting of glaciers around the fringes of Greenland. Satellite data was not good enough to measure the melt nearer sea level.
Most models of global warming indicate that the Greenland ice might melt within thousands of years if warming continues.
Oceans would rise by about 70 meters if the far bigger ice-cap on Antarctica melted along with Greenland. Antarctica's vast size acts as a deep freeze likely to slow any melt of the southern continent.
The panel that advises the United Nations has predicted that global sea levels might rise by almost a meter by 2100 because of a warming climate.
Such a rise would swamp low-lying Pacific islands and warming could trigger more hurricanes, droughts, spread deserts and drive thousands of species to extinction.
Still, a separate study in Science on Thursday said sea levels were probably rising slightly because of a melt of ice sheets.
"Ice sheets now appear to be contributing modestly to sea level rise because warming has increased mass loss from coastal areas more than warming has increased mass gain from enhanced snowfall in cold central regions," it said.
"Greenland presently makes the largest contribution to sea level rise," according to the report by scientists led by Richard Alley of Pennsylvania State University in the United States.
© 2005 Cable News Network LP, LLLP. An AOL Time Warner Company. All Rights Reserved. |
Photo: Michael Hinkes/Alaska Image Library |
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Published on Sunday, November 20, 2005 by the lndependent/UK
The Big Thaw: Global Disaster Will Follow If the Ice Cap on Greenland Melts
Now scientists say it is vanishing far faster than even they expected.
by Geoffrey Lean
Greenland's glaciers have begun to race towards the ocean, leading scientists to predict that the vast island's ice cap is approaching irreversible meltdown, The Independent on Sunday can reveal.
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Research to be published in a few days' time shows how glaciers that have been stable for centuries have started to shrink dramatically as temperatures in the Arctic have soared with global warming. On top of this, record amounts of the ice cap's surface turned to water this summer.
The two developments — the most alarming manifestations of climate change to date — suggest that the ice cap is melting far more rapidly than scientists had thought, with immense consequences for civilisation and the planet. Its complete disappearance would raise the levels of the world's seas by 20 feet, spelling inundation for London and other coastal cities around the globe, along with much of low-lying countries such as Bangladesh.
Thermohaline circulation shutdown
More immediately, the vast amount of fresh water discharged into the ocean as the ice melts threatens to shut down the Gulf Stream, which protects Britain and the rest of northern Europe from a freezing climate like that of Labrador.
The revelations, which follow the announcement that the melting of sea ice in the Arctic also reached record levels this summer, come as the world's governments are about to embark on new negotiations about how to combat global warming.
This week they will meet in Montreal for the first formal talks on whether there should be a new international treaty on cutting the pollution that causes climate change after the Kyoto protocol expires in seven years' time. Writing in The Independent yesterday, Tony Blair called the meeting "crucial", adding that it "must start to shape an inclusive global solution". But little progress is expected, largely because of continued obstruction from President George Bush.
The new evidence from Greenland, to be published in the journal Geophysical Research Letters, shows a sudden decline in the giant Helheim glacier, a river of ice that grinds down from the inland ice cap to the sea through a narrow rift in the mountain range on the island's east coast.
Professor Slawek Tulaczyk, of the Department of Earth Sciences at the University of California, Santa Cruz, told the IoS that the glacier had dropped 100 feet this summer.
Over the past four years, the research adds, the front of the glacier — which has remained in the same place since records began — has retreated four and a half miles. As it has retreated and thinned, the effects have spread inland "very fast indeed", says Professor Tulaczyk. As the centre of the Greenland ice cap is only 150 miles away, the researchers fear that it, too, will soon be affected.
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Moving towards the sea at a rate of 113 feet a year; normal annual speed of a glacier is just one foot
The research echoes disturbing studies on the opposite side of Greenland: the giant Jakobshavn glacier — at four miles wide and 1,000 feet thick the biggest on the landmass — is now moving towards the sea at a rate of 113 feet a year; the normal annual speed of a glacier is just one foot.
The studies have found that water from melted ice on the surface is percolating down through holes on the glacier until it forms a layer between it and the rock below, slightly lifting it and moving it toward the sea as if on a conveyor belt.
This one glacier alone is reckoned now to be responsible for 3 per cent of the annual rise of sea levels worldwide.
"We may be very close to the threshold where the Greenland ice cap will melt irreversibly," says Tavi Murray, professor of glaciology at the University of Wales. Professor Tulaczyk adds: "The observations that we are seeing now point in that direction."
Until now, scientists believed the ice cap would take 1,000 years to melt entirely, but Ian Howat, who is working with Professor Tulaczyk, says the new developments could "easily" cut this time "in half".
There is also a more immediate danger as the melting ice threatens to disrupt the Gulf Stream, responsible for Britain's mild climate. The current, which brings us as much heat in winter as we get from the sun, is driven by very salty water sinking off Greenland. This drives a deep current of cold ocean southwards, in turn forcing the warm water north.
Research at the Woods Hole Oceanographic Institute in Massachusetts has shown, that even before the glaciers started accelerating, the water in the North Atlantic was getting fresher in what it describes as "the largest and most dramatic oceanic change ever measured in the era of modern instruments".
Even before these discoveries, scientists had shortened to evens the odds on the Gulf Stream failing this century. When it failed before, 12,700 years ago, Britain was covered in permafrost for 1,300 years.
© 2005 Independent News & Media (UK) Ltd.
Common Dreams © 1997-2007 |
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Wednesday, 28 September 2005
Arctic ice 'disappearing quickly' By Richard Black Environment Correspondent, BBC News website
The area covered by sea ice in the Arctic has shrunk for a fourth consecutive year, according to new data released by US scientists.
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They say that this month sees the lowest extent of ice cover for more than a century.
The Arctic climate varies naturally, but the researchers conclude that human-induced global warming is at least partially responsible.
They warn the shrinkage could lead to even faster melting in coming years.
"September 2005 will set a new record minimum in the amount of Arctic sea ice cover," said Mark Serreze, of the National Snow and Ice Data Center (NSIDC), Boulder, Colorado.
"It's the least sea ice we've seen in the satellite record, and continues a pattern of extreme low extents of sea ice which we've now seen for the last four years," he told BBC News.
September lows
September is the month when the Arctic ice usually reaches a minimum.
The new data shows that on 19 September, the area covered by ice fell to 5.35 million sq km (2.01 million sq miles), the lowest recorded since 1978, when satellite records became available; it is now 20% less than the 1978-2000 average.
The current rate of shrinkage they calculate at 8% per decade; at this rate there may be no ice at all during the summer of 2060.
An NSIDC analysis of historical records also suggests that ice cover is less this year than during the low periods of the 1930s and 40s.
Mark Serreze believes that the findings are evidence of climate change induced by human activities.
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"It's still a controversial issue, and there's always going to be some uncertainty because the climate system does have a lot of natural variability, especially in the Arctic," he said.
"But I think the evidence is growing very, very strong that part of what we're seeing now is the increased greenhouse effect. If you asked me, I'd bet the mortgage that that's just what's happening."
Confusing movement
One of the limitations of these records is that they measure only the area of ice, rather than the volume.
"One other factor could be movements of sea ice," said Liz Morris, of the British Antarctic Survey, currently working at the Scott Polar Research Institute in Cambridge, UK.
"If it all piles up in one place, you might have the same total amount of ice," she told the BBC News website, "and there is some evidence that ice is piling up along the north Canadian coast, driven by changes in the pattern of winds and perhaps ocean currents."
Most data on sea ice thickness comes from records of military submarines, which regularly explored passages under the Arctic ice cap during the Cold War years.
Submarines can cross the Arctic Ocean along tracks taken decades before, and note differences in the ice thickness above; but that may mean little if the ice itself has moved.
Professor Morris is involved in a new European satellite, Cryosat, which should be able to give definitive measurements of ice thickness as well as extent; its launch is scheduled for 8 October.
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But she also believes that the NSIDC data suggests an impact from the human-enhanced greenhouse effect.
"All data goes through cycles, and so you have to be careful," she said, "but it's also true to say that we wouldn't expect to have four years in a row of shrinkage.
"That, combined with rising temperatures in the Arctic, suggests a human impact; and I would also bet my mortgage on it, because if you change the radiation absorption process of the atmosphere (through increased production of greenhouse gases) so there is more heating of the lower atmosphere, sooner or later you are going to melt ice."
Arctic warming fast
Though there are significant variations across the region, on average the Arctic is warming twice as fast as the rest of the planet, according to a major report released last year.
The Arctic Climate Impact Assessment, a four-year study involving hundreds of scientists, projected an additional temperature rise of 4-7C by 2100.
If the current trend can be ascribed in part to human-induced climate change, Mark Serreze sees major reasons for concern.
"What we're seeing is a process in which we start to lose ice cover during the summer," he said, "so areas which formerly had ice are now open water, which is dark.
"These dark areas absorb a lot of the Sun's energy, much more than the ice; and what happens then is that the oceans start to warm up, and it becomes very difficult for ice to form during the following autumn and winter.
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"It looks like this is exactly what we're seeing - a positive feedback effect, a 'tipping-point'."
The idea behind tipping-points is that at some stage the rate of global warming would accelerate, as rising temperatures break down natural restraints or trigger environmental changes which release further amounts of greenhouse gases.
Possible tipping-points include
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Thursday, 11 August 2005 Siberia's rapid thaw causes alarm
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The world's largest frozen peat bog is melting, which could speed the rate of global warming, New Scientist reports.
The huge expanse of western Siberia is thawing for the first time since its formation, 11,000 years ago.
The area, which is the size of France and Germany combined, could release billions of tonnes of greenhouse gases into the atmosphere.
This could potentially act as a tipping point, causing global warming to snowball, scientists fear.
The situation is an "ecological landslide that is probably irreversible and is undoubtedly connected to climatic warming," researcher Sergei Kirpotin, of Tomsk State University, Russia, told New Scientist magazine.
The whole western Siberian sub-Arctic region has started to thaw, he added, and this "has all happened in the last three or four years".
Warming fast
Western Siberia has warmed faster than almost anywhere on the planet, with average temperatures increasing by about 3C in the last 40 years.
The warming is believed to be due to a combination of man-made climate change, a cyclical atmospheric phenomenon known as the Arctic oscillation and feedbacks caused by melting ice.
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The 11,000-year-old bogs contain billions of tonnes of methane, most of which has been trapped in permafrost and deeper ice-like structures called clathrates.
But if the bogs melt, there is a big risk their hefty methane load could be dumped into the atmosphere, accelerating global warming.
Scientists have reacted with alarm at the finding, warning that future global temperature predictions may have to be revised.
"When you start messing around with these natural systems, you can end up in situations where it's unstoppable," David Viner, of the University of East Anglia, UK, told the Guardian newspaper. "There are no brakes you can apply.
"This is a big deal because you can't put the permafrost back once it's gone. The causal effect is human activity and it will ramp up temperatures even more than our emissions are doing."
The intergovernmental panel on climate change speculated in 2001 that global temperatures would rise between 1.4C and 5.8C between 1990 and 2100.
However these estimates only considered global warming sparked by known greenhouse gas emissions.
"These positive feedbacks with landmasses weren't known about then," Dr Viner said. "They had no idea how much they would add to global warming.
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A record loss of sea ice in the Arctic summer has convinced scientists that the northern hemisphere may have crossed a critical threshold beyond which the climate may never recover.
Scientists fear that the Arctic has now entered an irreversible phase of warming which will accelerate the loss of the polar sea ice that has helped to keep the climate stable for thousands of years.
Dr Serreze: "This will be four Septembers in a row that we've seen a downward trend. The feeling is we are reaching a tipping point or threshold beyond which sea ice will not recover."
Professor Wadhams: "As the sea ice melts, and more of the sun's energy is absorbed by the exposed ocean, a positive feedback is created leading to the loss of yet more ice."
"If anything we may be underestimating the dangers. The computer models may not take into account collaborative positive feedback."
"Sea ice keeps a cap on frigid water, keeping it cold and protecting it from heating up."
"Losing the sea ice of the Arctic is likely to have major repercussions for the climate."
"There could be dramatic changes to the climate of the northern region due to the creation of a vast expanse of open water where there was once effectively land."
"You're essentially changing land into ocean and the creation of a huge area of open ocean where there was once land will have a very big impact on other climate parameters."
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Photo: Tim Bowman/Alaska Image Library |
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Wednesday, 29 October, 2003 Big melt warning for Arctic
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The ice covering the Arctic Ocean is getting thinner as summers lengthen, say British scientists.
Melting seen in recent years is set to continue, they warn, with the eventual disappearance of ice during the summer months.
It puts the habitat of the polar bear, which relies on the ice to hunt for seals, under increasing threat.
Melting will also increase the effects of global warmingin the northern hemisphere, say researchers from University CollegeLondon (UCL) and the Met Office Hadley Centre for Climate Predictionand Research.
The study, reported in the journal Nature, is based onice thickness measurements from two European Space Agency (Esa)satellites, ERS-1 and ERS-2.
The team also used microwave images from an American satellite.
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Ice-free summer
Lead researcher Dr Seymour Laxon of UCL said the resultsfrom the American satellite showed that the length of summers hadincreased over the last 25 years.
"When we compared the data from the two satellites wewere astonished by the similarity between changes in the ice thicknessand the length of the summer melt season," he said.
"This result suggests that if this continues, furthermelting will occur, leading to the eventual disappearance of the iceduring summer."
Ice in the Arctic Ocean has already thinned by 40% in the past 40 years, according to the results of submarine surveys.
Any further loss could spell disaster for the polar bear, which stands to lose its natural habitat.
Global warming
It also has implications for global warming.
As the icemelts, more sunlight is absorbed rather than being reflected back intospace, amplifying the effects.
But climate studies are hotly debated and not all researchers agree with this bleak picture. |
Computer modelling studies suggest there could be an alternative explanation for the apparent loss of sea ice.
Some experts believe a change in atmospheric circulation patterns has led to the ice being redistributed further north.
It could all be bunched up in the permanent polar pack north of Greenland and Canada, they say.
Heated debate
Martin Doble of the sea ice group at the Scottish Association for Marine Science is sympathetic to this view.
He says the ERS satellites are not designed to study the planet's poles and cannot sample the area beyond 81.5 degrees north.
This means they miss most of the central Arctic pack iceand the area of maximum interest north of Greenland and the CanadianArchipelago.
"One of the major debates in Arctic research at themoment is whether the total volume of sea ice in the Arctic hasactually reduced as much as submarine results say that it has," he toldBBC News Online.
"This latest paper adds nothing to this debate, since it misses this area entirely."
Settling the argument once and for all may have to wait until the launch of a more advanced Esa satellite - Cryosat - in 2004.
Its primary objective is to test the prediction of thinning Arctic ice due to global warming.
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Arctic Temperatures Warming Rapidly
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OTTAWA — Summer temperatures in the Arctic have risen at an incredible rate over the past three years and large patches of what should be ice are now open water, a British polar explorer said on Monday.
Ben Saunders, forced by the warm weather to abandon an attempt to ski solo from northern Russia across the North Pole to Canada, said he had been amazed at how much of the ice had melted.
"It's obvious to me that things are changing a lot and changing very quickly," a sunburned Saunders told Reuters less than two days after being rescued from the thinning ice sheet close to the North Pole.
"I do know it's happening because that was my third time in the Arctic (in the last three years)," said Saunders, who explored the region in 2001 and 2003.
An international study last year said global warming would melt most of the Arctic icecap in summertime by the end of the century. Many scientists blame the rising temperatures on human emissions of greenhouse gases while others point to what they say are longer-term natural warming and cooling cycles.
"The temperatures were incredibly warm ... I had days when I could ski with no gloves and no hat at all, just in bare hands, because I was too hot," said Saunders.
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Logs from an expedition in 2001 showed the average Arctic temperature at this time of year was plus 5 to minus 4 degrees Fahrenheit.
Saunders said the average temperature this time was just 23 to 19 degrees Fahrenheit.
"I saw open water every single day of the expedition, which is not what I was expecting," said Saunders, who had to don a special thermal suit and drag his sled across open patches of water nine times during the 71 days he spent alone. He covered a total of 600 miles before giving up.
"I think a ski crossing from land to land (Russia to Canada) if conditions stay the same — let alone get any worse — is impossible," he said.
Saunders had planned to set off from Russia's northernmost Arctic islands in March but instead of ice, he discovered a 34 mile open stretch of water. He had to be flown to the closest pack ice.
"The ice was terrible, right from the word go; very smashed up, very few flat areas," he said, adding that the usually impermeable multiyear ice was thinning.
"(It) is becoming less stable and it's breaking up more easily. There are enormous pressure ridges, and enormous areas of what I'd describe as rubble."
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Saunders said he had also been struck by the almost complete absence of polar bears on the Russian side.
"That surprised me a lot ... that's historically been a very concentrated area for bears," he said.
"Whereas in 2001 we were attacked by a bear on day two (of the trek) and saw bear tracks nearly every day for the first three weeks, this year I saw four sets of tracks during the entire expedition."
Polar bears hunt out on the ice during summer months and are forced to retreat back to land when the ice is too thin.
Saunders said the weather had been poor for much of the trip with much more cloud cover and fog than he had expected. The fresh snow he encountered was soft and bulky, unlike the typical hard, fine-grained snow found in the Arctic.
©Waukon Standard 2004 |
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Saturday, 10 January, 2004
Greenland ice-melt 'speeding up'
First you hear a savage cracking sound, next the rolling crash of thunder.
Then as the icebergs rip away from the margin of the ice-sheet they plunge into the grey waters of the Atlantic with a roar that echoes around the mountains.
Nothing prepares you for the sheer scale and drama of events in this forbidding terrain and all the signs are that the changes at work here are gathering pace.
The only way to reach the ice-sheet is by helicopter — a spectacular flight through remote fjords and the jagged blue-white rubble of the ice.
We travelled with Danish scientist Carl Boggild of GEUS, the Geological Survey of Denmark and Greenland.
For the past few years he has been managing a network of 10 automatic monitoring stations and his first results are alarming — the edges of the ice-sheet are melting up to 10 times more rapidly than earlier research had indicated.
Cracks and crevasses
In 2001 NASA scientists published a major study based on observations by satellite and aircraft.
It concluded that the margins of the Greenland ice-sheet were dropping in height at a rate of roughly one metre a year.
Now, amid some of the most hostile conditions anywhere on the planet, Carl Boggild and his team have recorded falls as dramatic as 10 metres a year — in places the ice is dropping at a rate of one metre a month.
The glacier we visited — the Sermilik glacier in southern Greenland — is so volatile that one automatic monitoring station was lost into a yawning crevasse.
Between a maintenance visit in May and our visit this month, new cracks had opened up in the icy surface and we had to help shift one of the devices to a safer position.
Engravings from the late 19th Century show how the glacier once reached far into the ocean and satellite pictures highlight how the retreat has accelerated — the glacier dropping an astounding 150 metres in the last 15 years.
The latest data shows the melting picking up even more speed.
Heating up?
A vicious wind whipping across 2,000 kilometres of solid ice — the length of the Greenland ice-sheet — chilled us as we filmed.
But the feeling of cold was ironic — it is the rise in air temperatures recorded here that is at least partly responsible for the sudden acceleration of the melting.
Dr Boggild and his colleagues, studying the physics of how the air and ice relate, conclude that as much as 55% of the melting is attributable to warming in the air.
He is cautious to avoid blaming climate change too readily: "Maybe if we look back after 50 years and see how temperatures have risen, then we can call it climate change."
Sea level rise
Dr Boggild is all too aware of how easily he could be accused of jumping onto a climate change bandwagon.
But he is adamant that the results he has gathered so far are reliable.
"We can say for certain that the rate of melting has increased and we can say for certain that the height of the ice-sheet is falling, even allowing for increased ice-flow.
"There is no doubt that something very major is happening here."
As we speak, he checks the instruments on the automatic station.
A large range of data is collected and transmitted via satellite to Copenhagen every six hours.
For the first time, scientists should have a long-term, on-the-ground view of the changes taking place here.
Just before we leave, there is another roar as more icebergs crash into the ocean
Many more icebergs falling into the sea will cause two things to happen — the sea-level will rise and the injection of freshwater could disrupt the ocean currents, including the Gulf Stream.
What happens in this remote barren land has the potential to affect us all.
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WMDs for the Taking?
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Studies suggest that even a modest rise in temperature would make the global average as high as it’s been in the last 150,000 years
By Carl Zimmer
NEWSWEEK INTERNATIONAL Dec. 1 2003 issue — Just last October, when the U.S. Senate debated a bill that would have curbed emissions of carbon dioxide, the most critical greenhouse gas, Republican Sen. James Inhofe of Oklahoma helped defeat the measure by declaring that “the science underlying this bill has been repudiated.” A few weeks later, one of Inhofe’s favorite pieces of evidence looks like it has been torpedoed. ALTHOUGH TEMPERATURE measurements taken on the ground have shown a clear warming trend at least back to the 1950s, important satellite data have until now shown no evidence of warming whatsoever. That’s a discrepancy big enough to drive an SUV through. In last week’s issue of the Journal of Climate, however, scientists have essentially resolved it. In a thorough analysis of the data going back 24 years, they’ve found that the atmosphere has in fact been warming about 0.1 degrees Celsius per decade. |
That data has become another piece of evidence confirming a rise in the temperature in the past few decades.
The study concentrated on a set of NASA satellites that beam back temperature measurements of Earth’s troposphere — the lower atmosphere up to about 15 kilometers.
If there had been any climate change at all, it should have shown up in that part of the atmosphere near the ground, but studies in the 1990s failed to find any.
There were plenty of reasons why: satellites can be finicky and prone to subtle errors.
Scientists have to compensate for factors that can skew the data, like changes in altitude over time.
A team of scientists from Remote Sensing Systems in California took a more thorough look at the data, fitting together data from two series of readings that overlapped in the 1980s.
Absent action of carbon dioxide emissions
They also worked with U.S. government scientists to compare their new analysis with computer programs that re-create the past century of climate change, absent the action of carbon dioxide emissions.
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By the end of the 20th century, they concluded, the patterns of temperatures had drifted significantly higher than natural variability — a fingerprint, as it were, left by manmade global warming.
When it comes to predicting how much temperatures will rise this century, there’s still plenty of uncertainty to go around.
Back in 2001, the Intergovernmental Panel on Climate Change concluded that the temperatures might rise anywhere from 1.5 to 5.8 degrees Celsius — a huge range.
Recently scientists’ predictions have begun to converge on a narrower range, and the forecasts have gotten more modest.
James Hansen of the NASA Goddard Institute for Space Studies in New York has pointed out that in recent years the actual rise of greenhouse gases hasn’t accelerated as fast as the IPCC predicted.
Carbon-dioxide emissions increased 4.7 percent a year from 1945 to 1973, but since then, the average increase has been only 1.4 percent a year.
The rate for methane, another powerful greenhouse gas produced in landfills and rice farming, is barely increasing at all.
Hansen thinks that even if nothing is done, the planet would warm only 1.5 degrees by 2050.
Can we handle even this modest increase?
Studies of ancient climates, as revealed in ice-core samples taken from glaciers, suggest that even a modest rise would make the global average temperature as high as it’s been in the past 150,000 years.
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There’s a risk that ice shelves will begin to melt, raising sea levels and flooding coastlines; earlier this month, Australian scientists reported that the sea ice around Antarctica has already shrunk by 20 percent since 1950.
There’s always a chance that scientists have left something out that will confound their predictions.
At a climate meeting in Berlin this spring, Nobelist Paul Crutzen and colleagues raised serious concerns that pollution is masking the full impact of greenhouse-gas emissions.
Aerosols — haze, smog and other fine particles — can reflect sunlight back into space, creating a cooling shield over the atmosphere.
Even poor countries are working hard to cut down on air pollution for the health of their citizens, even as carbon levels rise.
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If they succeed in making the air cleaner, temperatures may soar — perhaps by as much as seven to 10 degrees Celsius.
This uncertainty makes it hard to prepare for the future.
If you’re trying, for instance, to protect a nation’s supply of drinking water, what you want are probabilities — to be able to say, for example, that there is only a 5 percent chance that the planet will heat more than four degrees.
These sorts of percentages would require fine-tuning of complex computer climate models — which in turn requires far more processing power than any research center currently has.
An English team of meteorologists has set up a program to find that power among the thousands of idle PCs on the Internet.
Since September, they’ve enlisted more than 18,000 computers to help crunch climate data (www.climateprediction.net).
If global warming is going to affect us all, we might as well pitch in to figure out what the future holds.
Zimmer is author of the book “Soul Made Flesh,” which is due out in January. |
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MSNBC © 2003 |
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Photo: U.S. Fish and Wildlife Service/Alaska Image Library |
Antarctic Ice Shelves Melting Ice shelves act as huge conveyer belts taking the continent’s snow cover out to the surrounding seas |
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