Glacier Melting a Key Clue to Tracking Climate Change

SINGAPORE/ANCHORAGE (Reuters) - The world has become far too hot for the aptly named Exit Glacier in Alaska.

Like many low-altitude glaciers, it's steadily melting, shrinking two miles (3 kilometres) over the past 200 years as it tries to strike a new balance with rising temperatures.

At the Kenai Fjords National Park south of Anchorage, managers have learned to follow the Exit and other glaciers, moving signs and paths to accommodate the ephemeral rivers of blue and white ice as they retreat up deeply carved valleys.

"Some of the stuff is changing fast enough that we now have signs on moving pedestals," said Fritz Klasner, natural resource specialist at Kenai Fjords.

The vast amounts of water stored in glaciers play crucial roles in river flows, hydropower generation and agricultural production, contributing to steady run-off for Ganges, Yangtze, Mekong and Indus rivers in Asia and elsewhere.

But many are melting rapidly, with the pace picking up over the past decade, giving glaciers a central role in the debate over causes and impacts of climate change.

That role has come even more sharply into focus after recent attacks on the U.N.'s climate panel, which included a wrong estimate for the pace of melting for Himalayan glaciers in a major 2007 report.

The report said Himalayan glaciers could all melt by 2035, an apparent typographical error that stemmed from using literature not published in a scientific journal. Climate sceptics seized on the error and used it to question the panel's findings on climate change.

The evidence for rapid glacial melting, though, is overwhelming.

The problem is no one knows exactly what's occurring in the more remote Himalayas and parts of the Andes. Far better measurements are crucial to really understand the threat to millions of people downstream.

"There is no serious information on the state of the melting of the glaciers in the Himalayan-Tibetan complex," Kurt Lambeck, President of the Australian Academy of Science, told a climate science media briefing in late February.

The high altitude and remoteness of many glaciers in the Himalayas and Andes is the main reason.

DATA IN A DEEP FREEZE

To try to fill the gap, Indian Prime Minister Manmohan Singh said last month the government would establish a National Institute of Himalayan Glaciology in Dehra Dun in the north.

In Europe and North America, glaciers are generally more accessible and there are more trained people to study them.

Switzerland's Aletsch glacier, the largest in the Alps, has been retreating for about 150 years.

But the glacier, which feeds the River Rhone, still stores an estimated 27 billion tonnes of ice, according to www.swissinfo.ch. That's about 12 million Olympic-sized swimming pools.

In 2008, a total of 79 Swiss glaciers were in retreat, while 5 were advancing, the Swiss Glacier Monitoring network says.

"There are a very small number of glaciers that are monitored," said veteran glaciologist Ian Allison, pointing to less than 100 globally for which there are regular "mass-balance" measurements that reflect how much a glacier grows or shrinks from one year to the next.

Such measurements are the benchmark and several decades of data is regarded as the best way to build up an accurate picture of what's happening to a glacier.

Glaciers originate on land and represent a sizeable accumulation of snow and ice over the years. They tend to carve their way through valleys as more and more ice accumulates until the point where more is lost through melting than is gained.

THAT SHRINKING FEELING

"We probably know less about the total volume of glaciers than we do about how much ice there is in the big ice sheets in Greenland and Antarctic because a lot of it is in small mass areas and a lot of it is inaccessible," said Allison, leader of the Australian Antarctic Division's ice, ocean, atmosphere and climate programme.

The World Glacier Monitoring Service in Switzerland analyses mass balance data for just over 90 glaciers and says their average mass balance continues to decrease.

Since 1980, cumulative thickness loss of the reference glacier group is about 12 metres of water equivalent, it says in its latest 2007/08 report.

Estimates vary but glaciers and mountain caps could contribute about 70 cm (2.3 feet) to global sea levels, a 2009 report authored by Allison and other leading scientists says.

The "Copenhagen Diagnosis" report from the Climate Change Research Centre at the University of New South Wales says there is widespread evidence of more rapid melting of glaciers and ice-caps since the mid-1990s.

That means run-off from melting glaciers and ice-caps is raising sea levels by 1.2 millimetres a year, translating to up to 55 cm (1.8 feet) by 2100 if global warming accelerates.

In Nepal, the International Centre for Integrated Mountain Development says "mass-balance" measurements would provide direct and immediate evidence of glacier volume increase or decrease.

"But there are still no systematic measurements of glacial mass balance in the region although there are promising signs that this is changing," the centre said in a recent notice.

It said that based on studies, the majority of glaciers in the region are in a general condition of retreat.

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some people aren't helping

this just in: http://www.guardian.co.uk/environment/2010/jan/21/lisa-murkowski-epa-greenhouse-gases/print

infrastructural damage...solution?

at: http://online.wsj.com/article_email/SB10001424052748704576204574531373037560240-lMyQjAxMDA5MDAwNzEwNDcyWj.html

Keeping It Frozen

In Alaska, a low-tech solution helps the ground stay cold enough, for now

By JIM CARLTON

FAIRBANKS, Alaska—While the world debates the causes of climate change and what, if anything, to do about it, Alaskans are busy dealing with its consequences.

Permafrost, the frozen ground that lies just beneath the surface in most of the state, has become less stable in many areas, thanks in part to higher average air temperatures. It has begun to thaw in the warmer months and refreeze in the winter, causing shifts that wreak havoc on the structural integrity of the pipelines, railways, roads and buildings that sit on top of it.

"If we're going to build on frozen ground, we want to keep it frozen," says Dan White, director of the Institute of Northern Engineering at the University of Alaska Fairbanks.

To do that, engineers increasingly are turning to a low-tech solution: devices called thermosiphons that draw heat out of the ground. It's a solution that shows how effective even relatively simple ingenuity can be in the absence of a more comprehensive, policy-driven response to climate change. But Alaska's experience also shows the limits that such stopgap measures often run up against.

Alyeska Pipeline consultant Mike Mertz provides a look at how the company is coping with thawing permafrost on the Trans-Alaska Pipeline. The Wall Street Journal's Jim Carlton reports.

Alaska's permafrost has been degrading since 1982 amid record warm temperatures, according to a 2006 study funded by oil giant ConocoPhillips. Milder winters are keeping the permafrost in many areas from getting cold enough to stay frozen during summers that are also getting warmer. Between 1949 and 2007, average annual temperatures in Alaska rose 3.4 degrees Fahrenheit, including an increase of 6.3 degrees in the winter, according to the Alaska Climate Research Center at the University of Alaska Fairbanks.

Development worsens the problem by stripping vegetation, an effective insulator, from the surface, replacing it with heat-absorbing man-made materials or leaving the ground bare.

With permafrost thawing and refreezing in more of Alaska over recent years, highways and railroad tracks have to be constantly repaired because of cracks, heaving and sinking. All around Fairbanks, homes can be seen listing on foundations that have been unsettled as the permafrost underneath them has thawed, and buildings in many other parts of the state have the same problem.

That's where thermosiphons come in. The device essentially is a tube filled with gas that can't escape. Part of the tube is buried in the ground, with the top exposed in the air. As temperatures plunge in the winter, the gas condenses into a liquid and falls to the bottom of the tube.

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Jim Carlton/The Wall Street Journal

Thermosiphons protrude out of support beams on the Trans-Alaska Pipeline.

Heat Release

The relative warmth of the ground then causes the liquid to evaporate back into gas that rises to the top of the tube, where the heat it carries is dissipated into the air. The cycle keeps repeating itself, with no need for any kind of power source or any intervention other than maintenance. Scientists say the process cools the ground around a tube so much during the winter that it stays frozen even in summer.

Branching Out

Thermosiphons have been around in the Arctic for about 50 years. For most of that time they weren't used much outside of large infrastructure projects like the Trans-Alaska Pipeline, which is outfitted with about 120,000 of them. But they have been deployed more widely in recent years.

Arctic Foundations Inc., a company that specializes in ground-freezing systems, says its annual sales of the devices have jumped 50% over the past five years as it has installed them in hundreds of places in Alaska, including around schools and water tanks. The company, based in Anchorage, Alaska, has even used the devices as fence posts, since fences anchored by the usual kinds of posts are frequently "frost-jacked," or driven out of the ground by shifting soil, says Ed Yarmak, the firm's chief engineer.

One of the heaviest concentrations of thermosiphons is around Fairbanks, a metropolitan area of about 100,000 people. Among other uses, the devices ring a Federal Aviation Administration building, are stationed near utility poles and transmission towers, and have been installed along various roads in the area. On a one-mile stretch of Thompson Drive near the University of Alaska Fairbanks campus, engineers from the school put in a thermosiphon demonstration project five years ago. The devices are working as designed in keeping the ground frozen, says Doug Goering, dean of the school's college of engineering and mines.

The devices are being used in other Arctic regions, too. Arctic Foundations of Canada, an affiliate of the Alaskan company, says its sales of the devices have tripled over the past five years. That's partly because the thermosiphons have proved useful in shoring up structures in the many mines that have been opened in the Canadian Arctic in recent years, says John Jardine, president of the affiliate. Similar devices are being deployed in Russia and China, where they are helping stabilize the Qinghai-Tibet railroad.

Cost and Maintenance

While thermosiphons have proved effective, they aren't foolproof. Like any device, they sometimes malfunction. Alyeska Pipeline Service Co., an Anchorage-based company that operates the Trans-Alaska Pipeline, long ago embarked on a program to make sure that thermosiphons all along the pipeline keep working. Alyeska crews on the ground inspect the pipeline, using infrared cameras to scan the devices. If the telltale glow of heat being released is too dark, that indicates a gas blockage that may need repair.

In all, Alyeska has had to repair about 16,600 of its thermosiphons since 2001, or about 14% of the total, says Michelle Egan, an Alyeska spokeswoman.

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Jim Carlton/The Wall Street Journal

Thermosiphons flank a Federal Aviation Administration building in Fairbanks, Alaska. The devices help keep the permafrost frozen beneath buildings and infrastructure in Alaska by transferring heat out of the ground.

Also, while the use of thermosiphons has surged, cost is an issue for many users and potential users. The devices are available in different sizes, but typically each one cools an area no more than about 10 feet in diameter, so it can take many of them to protect a structure. To shore up a home with nine of the devices would cost around $20,000, and protecting infrastructure on a massive scale is of course far more expensive.

As a result, thermosiphons are being used strategically. For example, 14 of the devices were installed by Alaska state highway officials along a stretch of Chena Hot Springs Road outside Fairbanks about 16 years ago. The reason: The location lies at the bottom of a hill, where there is more permafrost, and so more permafrost-related problems, than in many steeper places, says John Zarling, professor emeritus of mechanical engineering at the University of Alaska Fairbanks.

"It's too costly to protect the whole world," Mr. Zarling explains. "So you pick the problem areas."

Artic Ice Caps

decent article on melting ice caps + effects:
http://uk.reuters.com/article/idUKTRE5356SA20090406