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by Paul Brown

Arctic tundra ‘will turn to forest’

May 18, 2013 in Warming

EMBARGOED until 2301 GMT on Friday 17 May

Tundra will turn into fir forests at the current levels of carbon dioxide Photo by Jason Hollinger

Tundra will turn into fir forests at the current levels of carbon dioxide.             Image: Jason Hollinger

By Paul Brown

Two sets of scientists, working independently, come to the same conclusion: that the Arctic will soon become ice-free and forested.

LONDON, 18 May – An ice-free Arctic, the disappearance of tundra and forests up to the edge of the newly open ocean is how the north will look as the natural world reacts to the new climate caused by carbon dioxide reaching 400 parts per million (ppm) in the atmosphere, according to analysis of new lake sediments.

So far scientists have been guessing what a warmer world will look like, but lake bed cores from Russia provide evidence of the trees and plants that thrived north of the Arctic Circle last time CO2 was at 400 ppm – a barrier broken earlier this month.

There is a time lag of up to 30 years for the temperature to be forced up by the extra CO2 in the atmosphere, so the scientists’ findings give a clue to what to expect by the middle of the century.

Julie Brigham-Grette of the University of Massachusetts Amherst, who led a team of international scientists, says summer temperatures were about 8°C warmer in the Arctic than they are today, and the rainfall three times greater. At the same time the West Antarctic ice sheet did not exist, showing that both landscape and sea level were vastly different.

Underestimating the effects

 

She said the results showed that scientists might have badly underestimated the effect of existing carbon dioxide levels in altering the climate over time.

Another unconnected team of researchers has been studying how the temperature changes that are already occurring in the northern hemisphere are affecting plants. The two pieces of research appear to point to the same conclusions.

Hans Tømmervik at the Fram-High North Research Centre for Climate and the Environment and 21 scientists from 17 academic institutions have been looking at all the Arctic countries and how they are already reacting to increased temperatures.

He said: “Norwegian climate and vegetation as we know it today might be totally changed within some decades. The same process is happening in Siberia, in Alaska and in the northern parts of Canada. Mountain plateaus become forest land and the winter period is shorter and shorter every year”.

The growing season has increased by up to 40 days in some areas. The temperature difference between summer and winter is getting smaller because the winters are no longer so cold. Spring and autumn seasons are also shorter.

Tømmervik says the start and end period for vegetation growth are very dependent on threshold temperatures. When the trends of these temperatures change and thus change the start of photosynthesis, it will in time change the vegetation.

Pollen in the sediment

 

The result is that trees and bushes will be able to grow where only lichen and heather were living earlier. Species move slowly towards the north and up into the mountains. The increased vegetation in the north also gives an extra boost to global warming, because it reflects less sunlight back into space than the ice and snow it has replaced, and thus causes even more rapid changes.

The other team were looking at sediment layers and analysed cores collected in the winter of 2009 from under ice-covered Lake El’gygytgyn, the oldest deep lake in the northeast Russian Arctic. “Lake E” was formed 3.6 million years ago when a huge meteorite hit the Earth and blasted out an 11-mile (18 km) wide crater.

It has been collecting sediment layers ever since. Luckily for geoscientists, it lies in one of the few Arctic areas not eroded by continental glaciers, so a thick, continuous sediment record was left remarkably undisturbed. Cores from Lake E reach back in geological time nearly 30 times farther than Greenland ice cores that cover the past 140,000 years.

“One of our major findings is that the Arctic was very warm in the Pliocene [~ 5.3 to 2.6 million years ago] when others have suggested atmospheric CO2 was very much like levels we see today. This could tell us where we are going in the near future.

“In other words, the Earth system response to small changes in carbon dioxide is bigger than suggested by earlier models”, say the co-authors from Russia, Germany and the United States.

Also important to the story are fossil pollens extracted from the lake sediments, which allow scientists to reconstruct life around the lake in the past using modern habitat tolerances to reconstruct past winter and summer temperatures and precipitation.

Another significant finding to emerge from this first continuous, high-resolution record of the Middle Pliocene is the documentation of sustained warmth, with summer temperatures of about 59 to 61° F [15 to 16°C], about 8°C warmer than today, and regional precipitation three times higher than today.

“We show that this warmth well north of the Arctic Circle occurred throughout both warm and cold orbital cycles and coincides, in part, with a long interval of 1.2 million years when the West Antarctic Ice sheet did not exist”, Brigham-Grette notes. Thus both poles share some common history, but the pace of change differed, she said  – Climate News Network

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by Kieran Cooke

Ground slows glacier ice loss

May 12, 2013 in Science

EMBARGOED until 2301 GMT on Sunday 12 May

One of the valley walls of the Petermann glacier in northern Greenland Image: NASA/Michael Studinger

One of the valley walls of the Petermann glacier in northern Greenland
Image: NASA/Michael Studinger

By Kieran Cooke

New understanding of some of Greenland’s major glaciers suggests they may not melt in the future nearly as fast as they are doing now.

LONDON, 13 May – Scientists tread very carefully when it comes to glaciers. While the consensus is that glaciers around the world are generally in retreat, there are the exceptions:

in the west of the Himalayas some glaciers have been found to be growing, not shrinking. In Antarctica some glaciers are gaining mass balance while others are losing it. Meanwhile glaciers in other parts of the world, particularly in the Andes,  are disappearing at an ever increasing rate.

The impact of climate change on the Greenland ice sheet has been well documented: Arctic temperatures are rising at levels well above the global average, and ice-loss has been accelerating.

This has raised concerns that these constantly increasing rates of ice loss will lead to a rise in sea levels that could threaten coastal communities around the world. Yet the future contribution of Greenland’s glaciers to sea-level rise is uncertain.

A new study published in the journal Nature questions whether present trends of ice loss on the Greenland ice sheet will be maintained.

The report – Future Sea-level Rise from Greenland’s Major Outlet Glaciers in a Warming Climate – looks at the behaviour of the four major fast flowing glaciers in Greenland. The Petermann, Kangerdlugssuaq, Helheim and Jakobshavn glaciers together drain about 22% of the island’s ice sheet.

Lower loss expected

 

By building up a computer model of these four glaciers, scientists have revealed that the shape of the ground beneath the ice has a marked impact on the way the ice moves, with the rate at which the glaciers are losing ice depending critically on the shape of the fjords in which they sit and the topography of the rock below them.

In turn, this has led the scientists to doubt whether present rates of ice loss and the “calving” of icebergs from the glaciers will be maintained.

“…While these glaciers may show several bursts of retreat and periods of high iceberg formation in future, the rapid acceleration seen in recent years is unlikely to continue unchecked”, says the report.

The computer model suggests that, because of the influence of various topographical features, the projected sea level rise from ice loss of these four glaciers will be of the order of between 2cm and 5cm by 2200 – considerably lower than previous estimates which have been based solely on the extrapolation of current trends.

However, the rate of  calculated ice loss will still be considerable: the model predicts that the combined ice loss of the four will amount to between 30 gigatonnes (Gt) and 47Gt per year over the present century. One Gt of ice is equivalent to one cubic kilometre of water. By way of comparison, Lake Geneva contains 90Gt of water.

More clarity needed

 

“I am excited by the way we have managed to create a detailed picture of the workings of the glaciers”, says Dr Faezeh Nick, of the Universite Libre de Bruxelles, lead author of the study.

“It turns out that if the fjord a glacier sits in is wide or narrow, it really affects the way the glacier reacts. The important role of the terrain below the ice shows we need to get a much clearer picture of the rest of Greenland’s glaciers before we have the whole story.”

Work on the modelling of the glaciers was carried out under the EU-funded Ice2sea programme which links scientific expertise among 24 institutions in Europe and elsewhere.

Professor David Vaughan, head of the programme, told Climate News Network that though there were various ways of analysing the behaviour of glaciers, the new computer modelling could be vital in assessing future levels of ice loss.

“The key point is that we actually need to know about the land beneath the ice if we are going to come up with really good projections on future ice loss and the contribution to sea level rise of these glaciers. This computer modelling could be a big step forward and adds to our understanding of how glaciers behave.” – Climate News Network

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by Paul Brown

Antarctic Peninsula’s thaw speeds up

April 14, 2013 in Warming

EMBARGOED until 1700 GMT on Sunday 14 April

The ice core camp on James Ross Island: Scientists worked in shifts to drill to the base of the ice sheet. Image: Nerilie Abram

James Ross Island: Scientists worked in shifts to drill to the base of the ice sheet.
Image: Nerilie Abram

By Paul Brown

Ice in parts of the Antarctic Peninsula is now melting during the summer faster than at any time in the last thousand years, and the most marked speed-up in the thaw has occurred since 1960, scientists say.

LONDON, 14 April – Summer ice melt in the Antarctic Peninsula has increased almost 10-fold in the last 600 years,  weakening the area’s large ice shelves and reducing glacier size, scientists have discovered.

The findings explain a series of sudden collapses of ice shelves in the last 20 years, which scientists studying them had not expected. The researchers say the melting that is now occurring could lead to further dramatic events, making the loss of large quantities of ice on the Peninsula more likely, and adding to sea level rise.

The results are significant because in the last two decades scientists have been divided on whether the Antarctic would gain mass through extra snow falling and so reduce sea level rise, or would lose ice because of higher sea and air temperatures and so multiply the effect. The new data come from a 1,000-year Antarctic Peninsula climate reconstruction published in the journal Nature Geoscience.

In 2008 a UK-French team drilled a 364-metre ice core from James Ross Island, near the northern tip of the Peninsula, with the idea of measuring past temperatures in the area. What surprised them was that the core also gave an unexpected insight into ice melt in the region over that period.

Layers in the ice core showed periods when summer snow on the ice cap thawed and then refroze.  By measuring the thickness of these melt layers the scientists were able to examine how the history of melting compared with changes in temperature at the ice core site over the last thousand years.

In the last 600 years the temperature has increased by 1.6C, but only in the last 50 years has it reached a level at which summer melting has increased dramatically.

Lead author Dr Nerilie Abram of the Australian National University and the British Antarctic Survey (BAS) said: “We found that the coolest conditions on the Antarctic Peninsula and the lowest amount of summer melt occurred around 600 years ago.

“At that time temperatures were around 1.6°C lower than those recorded in the late 20th century and the amount of annual snowfall that melted and refroze was about 0.5%. Today, we see almost ten times as much (5%) of the annual snowfall melting each year.

“…even small changes in temperature can result in large increases in the amount of melting…”

“Summer melting at the ice core site today is now at a level that is higher than at any other time over the last 1,000 years.  And whilst temperatures at this site increased gradually in phases over many hundreds of years, most of the intensification of melting has happened since the mid-20th century.”

Dr Robert Mulvaney from the BAS led the ice core drilling expedition and co-authored the paper.  He said: “Having a record of previous melt intensity for the Peninsula is particularly important because of the glacier retreat and ice shelf loss we are now seeing in the area.

“Summer ice melt is a key process that is thought to have weakened ice shelves along the Antarctic Peninsula leading to a succession of dramatic collapses, as well as speeding up glacier ice loss across the region over the last 50 years.”

The changes in the Peninsula do not necessarily apply to other parts of Antarctica, for example the West Antarctic Ice sheet, where melting is occurring and there is potentially an even greater risk of large-scale sea level rise.

It is not yet clear that the levels of recent ice melt and glacier loss in West Antarctica are exceptional or are caused by human-driven climate changes.

However, Dr Abram said: “This new ice core record shows that even small changes in temperature can result in large increases in the amount of melting in places where summer temperatures are near to 0°C, such as along the Antarctic Peninsula, and this has important implications for ice instability and sea level rise in a warming climate.” – Climate News Network

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by Tim Radford

Clouds ’caused Greenland’s 2012 thaw’

April 5, 2013 in Science

FOR IMMEDIATE RELEASE

There were several factors which led to 2012's dramatic thaw in Greenland Image: Brocken Inaglory

There were several factors which led to 2012′s dramatic thaw in Greenland
Image: Brocken Inaglory

By Tim Radford

Last year’s brief but startlingly rapid melting of the Greenland ice sheet probably had nothing to do with climate change. What it did reveal was the limits of our current knowledge.

LONDON, 5 April – US scientists think they can explain why the Greenland ice sheet started melting at an unexpected and alarming rate in the summer of 2012. They blame it on unusual clouds.

In four days during July last year, Nasa satellite measurements revealed that 97% of the surface of the Greenland ice sheet had begun to thaw. The slush was even recorded at the summit of the icecap, more than three kilometres above sea level. This sudden, dramatic thaw was brief, but without precedent.

Greenland is home to three million cubic kilometres of ice. If all of it melted, sea levels globally would rise by more than seven metres. So climate scientists have for decades taken a keen interest in Greenland, and report that such sudden periods of dramatic melting occur roughly only once in 150 years.

In July 2012, observers blamed the record North American heat waves, and even wild fires in the tundra that might have sent columns of sunlight-absorbing soot to darken the snow.

But now Ralf Bennartz of the University of Wisconsin-Madison thinks he has the answer. He and colleagues report in Nature that while there would be more than one cause for such a huge change in the pattern of summer thaw, they focused on the role of low-level clouds.

Snow keeps itself cool by reflecting sunlight back into space. Low-level clouds, too, should keep land masses cool, by reflecting sunlight back into space.

But the scientists calculated that, under particular temperature conditions, clouds could be thin enough to permit solar radiation to filter through, but thick enough to trap some of the Sun’s energy as infra-red radiation even if it was reflected by the snow and ice on the ground. The extra heat trapped close to the ice surface was enough to push temperatures above freezing.

Complex influences

 

There would have been other factors to consider: air pressure, regional temperatures, wind speeds, turbulence, ocean currents and so on. Nobody last year was inclined to blame global warming for such an entirely unexpected phenomenon.

The short, sudden and very unusual event was just that, an unusual event, to be reconstructed months later by a combination of observations on the ground, remote sensing data and computer models.

But it told meteorologists and climate scientists something about the complexities of the interplay of light, land, air, water and ice in those latitudes.

“We know that these thin, low-level clouds occur frequently. Our results may help to explain some of the difficulties that current global climate models have in simulating the Arctic surface energy budget”, said Professor Bennartz.

“Above all, this study highlights the importance of continuous and detailed ground-based observations over the Greenland ice sheet and elsewhere.” - Climate News Network

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by Tim Radford

Warming ‘increases Antarctic ice’

March 31, 2013 in Science

EMBARGOED until 1700 GMT on Sunday 31 March

Some think global warming could be increasing Antarctic sea ice, while others are less sure Image: NASA

Some think global warming could be increasing Antarctic sea ice, while others are less sure
Image: NASA

By Tim Radford

The amount of ice in the Antarctic is increasing, scientists say – as a strange consequence of global warming. But at the other end of the world melting is proceeding apace.

LONDON, 31 March – The Arctic may be shrinking as the world warms but Antarctic sea ice is expanding. Blame global warming for that, too, say Dutch scientists.

The paradox is that increasing temperatures have set in motion a chain of events in the southern seas that have the opposite effect. Engineers call this negative feedback. So do Richard Bintanja and colleagues of the Royal Netherlands Meteorological Institute.

They report in Nature Geoscience that as the Antarctic ice shelves melt, the resulting cool fresh water has actually served to insulate the offshore sea ice from the warming ocean beneath the floating floes. So, as a consequence, in 2010 southern ocean sea ice reached a record extent.

The Arctic Ocean is mostly just that: ocean, which is getting warmer, and the northernmost parts of the globe have been warming at twice the global average rate.

So the north polar sea ice has been steadily thinning in depth and shrinking in area for more than 30 years. Ice reflects sunlight and keeps itself cold. Dark seas absorb sunlight and continue to get warmer.

As the Arctic ice shrinks, the feedback becomes positive. So the expectation is that sometime this century, in late summer, the Arctic ocean will for a few weeks be ice-free.

Plausible – and conclusive?

 

But Antarctica is an enormous, high continental landmass covered almost entirely by a huge depth of ice and snow, and it keeps itself cold very effectively. The oceans as a whole are warming – but in Antarctica, this warming has a counter-intuitive effect: thanks to the melt water, the total area of reflective sea ice is stable, or getting larger.

So although warm water is reaching the continental shelves, and creating some melting, the overall effect is to deliver a cold freshwater layer to the top hundred metres or so of the surrounding ocean. Fresh water freezes more quickly, so sea ice builds up quickly in the autumn and early winter.

“Our analyses indicate that the overall sea-ice trend is dominated by increased ice-shelf melt”, the Dutch scientists report.  “We suggest that cool sea surface temperatures around Antarctica could offset projected snowfall increases in Antarctica, with implications for estimates of future sea-level rise.”

That should be good news: there is enough ice on the southern continent to completely inundate most of the world’s great estuarine and sea level cities.  But the conclusions are tentative and not everybody is likely to agree.

Is this an effect that will last? The interaction of ocean and atmosphere is a complicated one, with a number of factors at work that influence the growth of sea ice. In the UK, Martin Siegert of the University of Bristol suspects that the process just described may not be significant in the long run.

Paul Holland of the British Antarctic Survey calls the freshwater concept “plausible” but thinks there are also plausible alternative explanations for the increase in sea ice around Antarctica, among them changes in the wind patterns that might deliver blasts of colder air to the surrounding seas.

Galloping change

 

And Andrew Russell of Brunel University agrees: he sees both wind pattern changes and ice shelf melting resulting in increased sea ice “which perhaps isn’t what you’d expect but is consistent with our best description of climate change.”

Meanwhile, scientists at the American Museum of Natural History have more bad news for polar bears and other creatures adapted to the frozen Arctic. It will get warmer, and greener.

Rising temperatures in the next few decades will lead to a “massive” increase in vegetation in the lands bordering the Arctic, with as much as 50% more tree cover.

Three weeks ago, an international team reported in Nature Climate Change that vegetation conditions had advanced hundreds of miles north in the last few decades.

Now a consortium of researchers from the New York museum, Woods Hole research centre, Cornell University and the University of York in the UK report in the same journal that the growth will continue.

They used climate models to simulate future conditions and they believe that positive feedback will guarantee the advance of mosses, dwarf shrubs, sedges, grasses and even trees towards the pole. As the ice and snow give way to green foliage, the rate of warming will step up.

“These impacts would extend far beyond the Arctic region,” said Richard Pearson of the American Natural History Museum. “For example some species of birds seasonally migrate from lower latitudes and rely on finding particular polar habitats, such as open space for ground nesting.” – Climate News Network

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by alex kirby

Canadian glaciers are melting fast

March 7, 2013 in Warming

FOR IMMEDIATE RELEASE

Canada's far north is melting - and there's probably no going back Image: David

Canada’s far north is warming – and there’s probably no going back
Image: David

By Alex Kirby

Many of the Canadian far north’s glaciers are likely to have melted by the end of the century, researchers believe, making significant sea-level rise inevitable.

LONDON, 7 March – Canada’s Arctic Archipelago glaciers will melt faster than ever in the next few centuries, research by European-funded scientists has shown.

They say 20% of the Canadian Arctic glaciers may have disappeared by the end of this century, which would mean an extra sea level rise of 3.5cm

The results of the research, part of the EU-funded ice2sea programme, will be published in Geophysical Research Letters this week, and the paper, Irreversible mass loss of Canadian Arctic Archipelago glaciers, is now available online.

The researchers developed a climate model for the island group in the north of Canada in which they simulated the shrinking and growing of glaciers in this area.

The model correctly “predicted” the ice mass loss measured over the last ten years, and the researchers then used it to look forward to project the effect of future climate change on the Arctic Archipelago glaciers.

The most important result of the research is that it shows that the melting will probably be irreversibie, according to lead author Dr Jan Lenaerts of Utrecht University.

He says: “Even if we assume that global warming is not happening quite so fast, it is still highly likely that the ice is going to melt at an alarming rate. The chances of it growing back are very slim.”

One main reason for this expected irreversibility is that snow melting on tundra, and sea ice loss from around the glaciers, will intensify regional warming.

Snow and sea ice reflect the sunlight, and when they disappear a large part of the sunlight will instead be absorbed by the land and the sea, raising the local temperature significantly.

Successful backcasting

 

In one scenario considered by the scientists 20% of the volume of the glaciers disappears by the end of this century. This would be accompanied by an average global temperature rise of 3°C.

But the regional rise around the Canadian ice caps - a form of glacier in which the ice flows to the sea in many directions – would be 8°C. And this is not an extreme scenario, Dr Lenaerts says.

Canada’s Arctic Archipelago glaciers are one of the largest ice bodies in the world after Greenland and the Antarctic. If they  melted completely, global average sea level would rise by 20 cms. Since the year 2000 the temperature in this area has risen by 1-2°C and the ice volume has already decreased significantly.

Professor David Vaughan, the programme leader of ice2sea, who is based at the British Antarctic Survey in Cambridge, UK, says: “Added to glaciers in Alaska, the Russian Arctic and Patagonia, these apparently small contributions add up to significant sea-level rise.

“A key success of this study was in showing that the model performed well in reproducing recently observed changes. That success gives us confidence in how the model predicts future changes”.

Glaciers in many parts of the world are undergoing rapid melting, although some experts argue that natural variability needs to be taken into account as well as climate change (and see our story of 3 March, Glaciers on the slide.) – Climate News Network

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by Tim Radford

Fast boat to China?

March 4, 2013 in Science

EMBARGOED until 2000 GMT on Monday 4 March

Safety will be just one problem for Arctic mariners Image: Ansgar Walk

Safety will be just one problem for Arctic mariners
Image: Ansgar Walk

By Tim Radford

In less than 50 years from now the north-west passage through the Arctic should be open to suitable vessels for a short time every other year, scientists have calculated.

LONDON, 4 March – The great Elizabethan explorer Martin Frobisher tried three times to get from Europe to China by sailing across the Arctic circle. In the summer of 1578 he steered his ships between the Canadian mainland and Baffin Island, in an attempt to find the fabled north-west passage.

He was soon defeated by tempest, snow and ice. “There fell so much snow, with such bitter cold air, that we could not scarce see one another for the same, nor open our eyes to handle our ropes and sails”, says the account recorded in Hakluyt’s famous Principal Navigations, Traffiques and Discoveries of the English Nation.

Tomorrow’s mariners may have an easier time of it, according to Laurence Smith, a geographer at University of California, Los Angeles. He reports in the Proceedings of the National Academy of Sciences that by 2059 ships, especially if reinforced for polar waters, should be able to manage the north-west passage from the east coast of America to the west, one year in two. Right now, it is navigable perhaps one year in seven.

The north-east passage, or northern sea route along the coast of Siberia, is already in regular use, and 46 ships made the journey in 2012. The Arctic ice sheet is expected to thin with global warming to a point where polar icebreakers will be able to go straight over the North Pole between the Pacific and Atlantic Oceans, he calculates.

Smith and his co-author Scott Stephenson considered seven different forecasts for sea ice cover in the Arctic between 2040 and 2059, and took an average. They studied the emerging navigation routes and the degree of sea ice melting that has made them possible.

They then considered two scenarios for climate change: one that assumed a 25% increase in carbon dioxide emissions, and one that assumed a 35% rise. And then they looked ahead to mid-century. To their surprise, the choice of scenarios made no difference to the outcome.

“No matter which carbon emission scenario is considered, by mid-century we will have passed a crucial tipping point – sufficiently thin sea ice – enabling moderately capable icebreakers to go where they please”, Smith said.

Seasonal shipping only

 

The attraction of the polar route is that it is shorter: substantially shorter than the traditional routes through the Suez or Panama Canals. Ships heading from New York for Yokohama, or from Bremen to Vancouver, via the Arctic Ocean, could save days at sea and cut running costs.

But the possibility also raises concerns about safety, suitable ports of call, and hazard to the Arctic environment. It also raises sovereignty issues, with increasing disputes about who “owns” the polar waters.

Such questions were, until 2007, largely hypothetical. But that year the Arctic sea ice, which has been shrinking and thinning gradually for decades, hit a record low.

Some glaciologists now think – though there is plenty of room for argument – that the Arctic may have reached a tipping point, and is about to enter a new and less stable state, in which ice cover will go on shrinking in the summer months.

One day, Frobisher’s unhappy voyage will be possible and may even become routine, but only in the late summer. “This will never be a year-round operation”, says Smith. – Climate News Network

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by Kieran Cooke

Glaciers on the slide

March 3, 2013 in Film reviews

EMBARGOED till 0001 GMT on Sunday 3 March

Greenland's glaciers face trouble - and so do many elsewhere Image: Christine Zenino

Greenland’s glaciers face trouble – and so do many others across the world
Image: Christine Zenino

By Kieran Cooke

If seeing really is believing, then James Balog’s film Chasing Ice is probably prompting a widespread outburst of faith. It shows the graphic evidence of how fast glaciers are melting worldwide.

LONDON, 3 March – You’d have to worry about James Balog’s knees. He has an operation on one leg and then, for a bit of gentle recuperation, goes walking on a glacier. Not surprisingly, before too long he needs to return to the surgeon’s table: then it’s back to the ice once more, only this time Balog is being lowered down into a crevasse, a cascade of freezing glacier melt water rushing within inches of his camera.

Balog is a photographer who has specialised for many years in what he describes as the “contact zone” between humans and nature. His work includes photos and documentaries on animals and forests, on the 2004 tsunami in Southeast Asia, on Hurricane Katrina and much, much more.

In 2006 he was given an assignment by National Geographic magazine to photograph glaciers and ice formations. He became a glacier groupie and the following year started the Extreme Ice Survey (EIS), photographing and filming glaciers round the world. Chasing Ice, released in the US last year and now doing the rounds of selected cinemas in the UK, captures the work of the EIS project.

Balog was once a climate change sceptic. Not any more. He and his team set up 28 time lapse cameras filming glaciers from Mount Everest in Nepal to Alaska, Greenland, Iceland and the Rockies in the US. Every half hour of daylight the cameras would click away, recording changes in glacier shape and size. The results, seen in the film, are startlingly clear.

“This is the memory of the landscape”, says Balog, standing by one of his cameras at a glacier in Greenland and holding up a small file of  film. “I never imagined you could see glaciers this big disappearing in such a short space of time. That landscape is gone and may never be seen again in the history of civilisation.”

Balog now tours the world with his photos and film showing, in his words,  “how extraordinary amounts of ice are disappearing with shocking speed.”  He wants people to see for themselves the visual evidence of climate change. “Seeing is believing”, he says.

Up an ice field on crutches

 

Chasing Ice is visually stunning: at one point young members of the survey team are camped out on the ice overlooking the Illulissat or Jakobshavn glacier half way up the west coast of Greenland. They’ve been there for days – the wind its threatening to blow the tent away, the cold is intense.

Then, in little over an hour, a piece of glacier more than half the size of Manhattan Island breaks or “calves” away. It’s the first time such a large-scale calving event has been captured on film. Giant pieces of ice shoot 600 feet up in the air, the glacier doing cartwheels, the deep, roaring sound echoing like the last breath of some giant, fatally wounded animal.

“The only way that you can really try to put it into scale with human reference is if you imagine Manhattan, and all of a sudden, all of those buildings just start to rumble, and quake, and peel off, fall over, and roll around”, says one of the film-makers.  “This whole massive city just breaking apart in front of your eyes.”

The film was not an easy one to make, with delicate electronic equipment being placed in some of the harshest conditions on the planet. Cameras would have to be secured by elaborate systems of anchors and wires. At one point Balog’s team return to the cameras to find the equipment has failed and months of  filming has been lost.

And then there are those knees. Towards the end of the film Balog is seen struggling up an ice field on crutches. There’s a postcript saying his knees have been repaired once again, this time with the aid of stem cell surgery. The EIS project is ongoing. Let’s hope the knees keep going as well. – Climate News Network

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by alex kirby

Arctic ice loses volume fast

February 16, 2013 in Science

EMBARGOED until 0001 GMT on Saturday 16 February

Not just what you see: the volume of ice is shrinking too Image: Patrick Kelley

Not just what you see: the volume of sea ice is shrinking too            Image: Patrick Kelley

By Alex Kirby

Researchers say the Arctic sea ice is not only undergoing seasonal shrinkage in area, but that it is also thinning and losing much of its volume.

LONDON, 15 February – The seasonal shrinkage of the area of Arctic sea ice is now well-established. But a new study has found that it is also undergoing thinning and a pronounced loss of volume all year round.

Between 2003 and 2012 the volume of the ice declined by 36% in the autumn and 9% in the winter, a UK-led team of scientists has discovered.

They used data from NASA’s ICESat satellite from 2003 to 2008, and new data from the European Space Agency’s CryoSat-2 satellite between 2010 and 2012, to estimate the volume of sea ice.

From 2003 to 2008, they found, autumn ice volumes averaged 11,900 cubic kilometres. But from 2010 to 2012 the average had dropped to 7,600 km3 – a decline of 4,300 km3. The average winter volume from 2003 to 2008 was 16,300 km3, dropping to 14,800 km3 between 2010 and 2012 – a difference of 1,500 km3.

“While two years of CryoSat-2 data aren’t indicative of a long-term change, the lower ice thickness and volume in February and March 2012, compared with same period in 2011, may have contributed to the record minimum ice extent during the 2012 autumn,” says Professor Christian Haas of York University, Canada, a co-author of the study.

The research was funded by the UK’s Natural Environment Research Council (NERC), the European Space Agency, the German Aerospace Center, Alberta Ingenuity, NASA, the Office of Naval Research and the National Science Foundation.

“The data reveals that thick sea ice has disappeared from a region to the north of Greenland, the Canadian Archipelago, and to the northeast of Svalbard,” said Dr Katharine Giles, a NERC-funded research fellow at the Centre for Polar Observation and Modelling (CPOM) at University College London, and another co-author of the report, published online in Geophysical Research Letters.

NERC says: “The findings confirm the continuing decline in Arctic sea-ice volume simulated by the Pan-Arctic Ice-Ocean Modelling & Assimilation System (PIOMAS), which estimates the volume of Arctic sea ice and had been checked using earlier submarine, mooring, and satellite observations until 2008.”

Ice volume a crucial indicator

 

PIOMAS was developed at the University of Washington’s Polar Science Center, which says of the part of the Arctic it studied: “Monthly averaged ice volume for September 2012 was 3,400 km3. This value is 72% lower than the mean over this period, [and] 80% lower than the maximum in 1979…”

Other satellites have already shown drops in the area covered by Arctic sea ice as the climate has warmed, and its extent reached a record minimum in September 2012.

But CryoSat-2, launched in April 2010, differs in its ability to allow scientists to estimate the volume of ice, a much more accurate indicator of the changes taking place in the Arctic.

NERC says the satellite measures ice volume using a high-resolution radar altimeter, which fires pulses of microwave energy down towards the ice.

The energy bounces off both the top of sections of ice and the water in the cracks in between. The difference in height between these two surfaces lets scientists calculate the volume of the ice cover.

The team confirmed CryoSat-2′s estimates of ice volume using measurements from three independent sources – aircraft, moorings, and NASA’s Operation IceBridge.

The decline in Arctic sea ice may have serious implications both regionally and globally. While much of the Sun’s heat is reflected back into space by light-coloured ice, more of it will be absorbed by the darker water exposed as the ice melts, speeding up the process of global warming.

The melting may also accelerate the thawing of the permafrost, allowing methane, a potent greenhouse gas, to escape to the atmosphere. It could also help to destabilise the Greenland ice cap.

The research findings were the result of collaboration between teams from UCL, the European Space Agency, the Jet Propulsion Laboratory, the University of Washington, York University, Alfred Wegener Institute for Polar & Marine Research, Woods Hole Oceanographic Institution, Morgan State University and the University of Maryland. – Climate News Network

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Avatar of Tim Radford

by Tim Radford

Thawing tundra threat to frozen carbon

February 11, 2013 in Science

 

Svalbard tundra - how fast it thaws is crucial Image: Billy Lindblom

Svalbard tundra – how fast it thaws is crucial            Image: Billy Lindblom

By Tim Radford

The melting of Arctic ice frozen for many thousands or even millions of years is speeding up, a potential route for carbon frozen deep below ground level to seep into the atmosphere.

LONDON, 12 February – The first kiss of sunlight on the frozen soils of the Arctic could spell increasing trouble as the world warms.

The return of the spring sun melts domes and lakes of frozen water called thermokarsts – karst is a word usually linked to limestone country, but it has been pressed into service as a label for the hard surfaces caused by ice.

Within this ice is dissolved organic carbon. Once the ice melts, microbes get to work releasing carbon dioxide into the air. The soil thaws, the surface collapses, lakes form, water flows, land surfaces erode which in turn releases more carbon dioxide to create more warming, to make the tundra even more vulnerable to spring thaw, and of course to accelerated warming.

This is not a scare story. It is happening now, according to Rose Cory of the University of North Carolina and colleagues who report in the Proceedings of the National Academy of Sciences.

They analysed water from 27 undisturbed sites in Alaska, and seven unique thermokarst failures – a polite word for landslides – near Toolik Lake in Alaska. The places they examined had been frozen for at least 10,000 years, and in some places two million years.

Speed the key factor

 

The team found dissolved organic carbon in all of them, and they found that newly-exposed muddy water was liable to surrender 40% more CO2 to the atmosphere.

This has of course been going on at the fringe of the Arctic permafrost for at least 10,000 years. The hazard is not in the process itself, but in its potential acceleration: nobody knows how much carbon is stored in the Arctic tundra as a greenhouse gas source, and nobody can guess what proportion of this will be released as the world warms. Thermokarsts are also found on a smaller scale in the Himalayas and the Swiss Alps.

But, as the soils warm, and the microbes get a chance to draw breath and get to work, say the authors, “the ultimate fate of deep, frozen soil carbon will be affected by coupled photobiological processing, by the available light field in streams that receive thermokarst drainage, and eventually by the landscape configuration of lakes and streams.”- Climate News Network

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