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Large increase in leakage of methane gas from the Arctic seabed
Methane is about 20 times more potent than CO2 in trapping solar heat.
Acting as a giant frozen depository of carbon such as CO2 and methane (often stored as compacted solid gas hydrates), Siberia's shallow shelf areas are increasingly subjected to warming and are now giving up greater amounts of methane to the sea and to the atmosphere than recorded in the past. |
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Published on Thursday, September 7, 2006 by the Associated Press Scientists Find New Global Warming 'Time Bomb’
by Seth Borenstein
WASHINGTON — Global warming gases trapped in the soil are bubbling out of the thawing permafrost in amounts far higher than previously thought and may trigger what researchers warn is a climate time bomb.
Methane — a greenhouse gas 23 times more powerful than carbon dioxide — is being released from the permafrost at a rate five times faster than thought, according to a study being published today in the journal Nature. The findings are based on new, more accurate measuring techniques.
“The effects can be huge,” said lead author Katey Walter of the University of Alaska at Fairbanks said. “It’s coming out a lot and there’s a lot more to come out.”
Scientists worry about a global warming vicious cycle that was not part of their already gloomy climate forecast: Warming already under way thaws permafrost, soil that has been continuously frozen for thousands of years. Thawed permafrost releases methane and carbon dioxide. Those gases reach the atmosphere and help trap heat on Earth in the greenhouse effect. The trapped heat thaws more permafrost and so on.
“The higher the temperature gets, the more permafrost we melt, the more tendency it is to become a more vicious cycle,” said Chris Field, director of global ecology at the Carnegie Institution of Washington, who was not part of the study. “That’s the thing that is scary about this whole thing. There are lots of mechanisms that tend to be self-perpetuating and relatively few that tend to shut it off.”
Some scientists say this vicious cycle is already under way, but others disagree.
Most of the methane-releasing permafrost is in Siberia. Another study earlier this summer in the journal Science found that the amount of carbon trapped in this type of permafrost — called yedoma — is much more prevalent than originally thought and may be 100 times the amount of carbon released into the air each year by the burning of fossil fuels.
It won’t all come out at once or even over several decades, but if temperatures increase, then the methane and carbon dioxide will escape the soil, scientists say.
The permafrost issue has caused a quiet buzz of concern among climate scientists and geologists. Specialists in Arctic climate are coming up with research plans to study the permafrost effect, which is not well understood or observed, said Robert Corell, chairman of the Arctic Climate Impact Assessment, a study group of 300 scientists.
“It’s kind of like a slow-motion time bomb,” said Ted Schuur, a professor of ecosystem ecology at the University of Florida and co-author of the study in Science.
Most of the yedoma is in little-studied areas of northern and eastern Siberia. What makes that permafrost special is that much of it lies under lakes; the carbon below gets released as methane. Carbon beneath dry permafrost is released as carbon dioxide.
Using special underwater bubble traps, Walter and her colleagues found giant hot spots of bubbling methane that were never measured before because they were hard to reach.
“I don’t think it can be easily stopped; we’d really have to have major cooling for it to stop,” Walter said.
Scientists aren’t quite sure whether methane or carbon dioxide is worse. Methane is far more powerful in trapping heat, but only lasts about a decade before it dissipates into carbon dioxide and other chemicals. Carbon dioxide traps heat for about a century.
“The bottom line is it’s better if it stays frozen in the ground,” Schuur said. “But we’re getting to the point where it’s going more and more into the atmosphere.”
Vladimir Romanovsky, geophysics professor at the University of Alaska at Fairbanks, said he thinks the big methane or carbon dioxide release hasn’t started yet, but it’s coming. In Alaska and Canada — which have far less permafrost than Siberia — it’s closer to happening, he said. Already, the Alaskan permafrost is reaching the thawing point in many areas.
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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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Climate warning as Siberia melts
11 August 2005 NewScientist.com news service Fred Pearce THE world's largest frozen peat bog is melting. An area stretching for a million square kilometres across the permafrost of western Siberia is turning into a mass of shallow lakes as the ground melts, according to Russian researchers just back from the region.
The sudden melting of a bog the size of France and Germany combined could unleash billions of tonnes of methane, a potent greenhouse gas, into the atmosphere.
The news of the dramatic transformation of one of the world's least visited landscapes comes from Sergei Kirpotin, a botanist at Tomsk State University, Russia, and Judith Marquand at the University of Oxford.
Kirpotin describes an "ecological landslide that is probably irreversible and is undoubtedly connected to climatic warming". He says that the entire western Siberian sub-Arctic region has begun to melt, and this "has all happened in the last three or four years".
What was until recently a featureless expanse of frozen peat is turning into a watery landscape of lakes, some more than a kilometre across. Kirpotin suspects that some unknown critical threshold has been crossed, triggering the melting.
Western Siberia has warmed faster than almost anywhere else on the planet, with an increase in average temperatures of some 3 °C in the last 40 years. The warming is believed to be a combination of man-made climate change, a cyclical change in atmospheric circulation known as the Arctic oscillation, plus feedbacks caused by melting ice, which exposes bare ground and ocean. These absorb more solar heat than white ice and snow.
Similar warming has also been taking place in Alaska: earlier this summer Jon Pelletier of the University of Arizona in Tucson reported a major expansion of lakes on the North Slope fringing the Arctic Ocean.
The findings from western Siberia follow a report two months ago that thousands of lakes in eastern Siberia have disappeared in the last 30 years, also because of climate change (New Scientist, 11 June, p 16). This apparent contradiction arises because the two events represent opposite end of the same process, known as thermokarsk.
In this process, rising air temperatures first create "frost-heave", which turns the flat permafrost into a series of hollows and hummocks known as salsas. Then as the permafrost begins to melt, water collects on the surface, forming ponds that are prevented from draining away by the frozen bog beneath. The ponds coalesce into ever larger lakes until, finally, the last permafrost melts and the lakes drain away underground.
Siberia's peat bogs formed around 11,000 years ago at the end of the last ice age. Since then they have been generating methane, most of which has been trapped within the permafrost, and sometimes deeper in ice-like structures known as clathrates. Larry Smith of the University of California, Los Angeles, estimates that the west Siberian bog alone contains some 70 billion tonnes of methane, a quarter of all the methane stored on the land surface worldwide.
His colleague Karen Frey says if the bogs dry out as they warm, the methane will oxidise and escape into the air as carbon dioxide. But if the bogs remain wet, as is the case in western Siberia today, then the methane will be released straight into the atmosphere. Methane is 20 times as potent a greenhouse gas as carbon dioxide.
In May this year, Katey Walter of the University of Alaska Fairbanks told a meeting in Washington of the Arctic Research Consortium of the US that she had found methane hotspots in eastern Siberia, where the gas was bubbling from thawing permafrost so fast it was preventing the surface from freezing, even in the midst of winter.
An international research partnership known as the Global Carbon Project earlier this year identified melting permafrost as a major source of feedbacks that could accelerate climate change by releasing greenhouse gases into the atmosphere. "Several hundred billion tonnes of carbon could be released," said the project's chief scientist, Pep Canadell of the CSIRO Division of Marine and Atmospheric Research in Canberra, Australia.
© 2005 Copyright Reed Business Information Ltd. |
 The world heated up by about 0.6 degrees last century, and the 1990s were the warmest decade on record, the International Panel on Climate Change (IPCC) says.Graph: BBC |
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 Scientists say average global temperatures have varied by less than one degree since the dawn of human civilisation, although they fluctuated much more before that.
The International Panel on Climate Change, IPCC, predicts a global rise of between 1.4C and 5.8C by the year 2100.Graph: BBC |
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Wednesday, 29 December, 2004
Earth's permafrost starts to squelch By Molly Bentley
in San Francisco
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In parts of Fairbanks, Alaska, houses and buildings lean at odd angles.
Some slump as if sliding downhill. Windows and doors inch closer and closer to the ground.
It is an architectural landscape that is becoming more familiar as the world's ice-rich permafrost gives way to thaw.
Water replaces ice and the ground subsides, taking the structures on top along with it.
Alaska is not the only region in a slump. The permafrost melt is accelerating throughout the world's cold regions, scientists reported at the recent Fall Meeting of the American Geophysical Union(AGU) in San Francisco.
In addition to northern Alaska, the permafrost zone includes most other Arctic land, such as northern Canada and much of Siberia, as well as the higher reaches of mountainous regions such as the Alps and Tibet. All report permafrost thaw.
"It's a very, very widespread problem," said Frederick Nelson, a geographer at the University of Delaware, US.
Scientists attribute the thaw to climate warming. As the air temperature warms, so does the frozen ground beneath it.
Data quest
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The observations reiterate the recent findings of the Arctic Climate Impact Assessment report, which attributed the northernpolar region's summer sea-ice loss and permafrost thaw to dramatic warming over the past half-century.
Thawing permafrost can cause buildings and roads to droop, and pipelines to crack.
Natural features are also affected. Scientists reported an increased frequency in landslides in the soil-based permafrost of Canada, and an increased instability and slope failures in mountainous regions, such as the Alps, where ice is locked in bedrock.
With the exception of Russia and its long history of permafrost monitoring, global records are insufficient — often too brief or scattered — to determine the precise extent of ice loss, said Dr Nelson.
However, monitoring programmes that are now much larger in scope, such as the Global Terrestrial Network for Permafrost (GTNP),indicate a warming trend throughout the permafrost zone.
Boreholes in Svalbard, Norway, for example, indicate that ground temperatures rose 0.4C over the past decade, four times faster than they did in the previous century, according to Charles Harris, a geologist at the University of Cardiff, UK, and a coordinator of Permafrost and Climate in Europe (Pace), which is contributing data to the GTNP.
"What took a century to be achieved in the 20th Century will be achieved in 25 years in the 21st Century, if this trend continues," he said.
"It's a very, very widespread problem," said Frederick Nelson, a geographer at the University of Delaware, US.
Scientists attribute the thaw to climate warming. As the air temperature warms, so does the frozen ground beneath it.
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Data quest
The observations reiterate the recent findings of the Arctic Climate Impact Assessment report, which attributed the northernpolar region's summer sea-ice loss and permafrost thaw to dramatic warming over the past half-century.
Thawing permafrost can cause buildings and roads to droop, and pipelines to crack.
Natural features are also affected. Scientists reported an increased frequency in landslides in the soil-based permafrost of Canada, and an increased instability and slope failures in mountainous regions, such as the Alps, where ice is locked in bedrock.
With the exception of Russia and its long history of permafrost monitoring, global records are insufficient — often too brief or scattered — to determine the precise extent of ice loss, said Dr Nelson.
However, monitoring programmes that are now much larger in scope, such as the Global Terrestrial Network for Permafrost (GTNP),indicate a warming trend throughout the permafrost zone.
Boreholes in Svalbard, Norway, for example, indicate that ground temperatures rose 0.4C over the past decade, four times faster than they did in the previous century, according to Charles Harris, a geologist at the University of Cardiff, UK, and a coordinator of Permafrost and Climate in Europe (Pace), which is contributing data to the GTNP.
"What took a century to be achieved in the 20th Century will be achieved in 25 years in the 21st Century, if this trend continues," he said.
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Slip and slide
In Ellesmere Island, Canada, a combination of warmer temperatures and sunny days has triggered an increasing frequency of detachment events, or landslides, over the past 25 years, compared with the previous 75, according to Antoni Lewkowicz, professor of geography at the University of Ottawa.
A detachment event occurs on a slope when the bottom of the active layer — the layer of thawing and freezing ground above permafrost — becomes slick with melted ice, causing it to slide off from the permafrost below.
But in this case, the amount of temperature increase is not so important as the rate of increase, Dr Lewkowicz found.
Meltwater from ice that warms slowly drains away. When ice warms quickly, water pools, creating a frictionless surface between the active layer and the permafrost. Like a stroll across a sloping icy sidewalk, a fall is almost certain.
"We have records from this particular site for about 10 or 12 years," said Dr Lewkowicz. "The years when active layer detachments have taken place have been times when we've had this rapid thaw down at the bottom of the active layer."
The slides may cut a wide swath hundreds of metres across, but extend only 50 or 60cm deep.
"They're almost skin-like landslides, moving across the permafrost," said Dr Harris.
The exposed permafrost, warmed by the air, now produces a new active layer.
Sink to source
In steep mountainous regions, permafrost thaw can lead to slope failure and rock falls.
In these areas, the permafrost ice is in hard rock. Where rocks are jointed, the ice serves as a kind of cement holding them together.
When it melts, the rock loses its strength and falls. Adramatic example of this occurred during the European heatwave of 2003 when a huge block of the Matterhorn broke off suddenly, leaving Alpine climbers stranded.
"It's not just the general warming trend we need to worry about," said Dr Harris, "but these extreme seasonal events as well."
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Dr Nelson says that with human-built structures, proper engineering and land use can mitigate permafrost loss.
Tingun Zhang, a researcher at the US National Snow and Ice Data Center in Boulder, Colorado, reported at the AGU on the particular challenge slumping ground presents to the construction of the Qinghai-Xizang railroad across Tibet, perhaps the most ambitious permafrost-zone project since the Trans-Alaskan pipeline.
Nearly half the railroad will lie across permafrost, and temperatures in the region are expected to rise during this century.
Engineers are using a simple — and long established — trick of cooling the permafrost with crushed rock. Rocks minimise heatintake in summer and promote heat loss in winter.
It is the first time a large-scale project is using the crushed-rock method as its primary solution, according to Dr Zhang.
But not all outcomes of permafrost thaw have precedent, or an immediate solution. One considerable variable is the possible release into the air of organic carbon stored in the permafrost.
In the drier areas, most of the emissions would be in the form of carbon dioxide (CO2). But in the wetter areas, it would be methane, a more effective greenhouse gas.
Scientists do not know exactly how much carbon is sequestered in the permafrost regions, but estimates show it could be up to a quarter of the sequestered carbon on Earth, 14% of it in the Arctic, alone.
"Will the Arctic be a carbon sink, or convert to a carbon source?" posed Dr Nelson. "It's a big unknown."
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  A six-part series looking at the biggest problems facing the Earth 
PART 5: CLIMATE CHANGE Rising tidesLife in Bangladesh's low-lying Ganges delta.
PART 6: FIGHTING POLLUTION Fight for clean airDurban poor take the pollution issue into their own hands COMPETITION Green and pleasantEnter our contest — design an eco-friendly garden FEATURES  Changing Earth — In pictures: Your changing worldReaders' pictures of the effects of pollution and climate change SECTIONS  RELATED BBC LINKS: RELATED INTERNET LINKS: |
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 Rising temperatures are thought to cause sea levels to rise as the oceans expand and polar ice melts.
The International Panel on Climate Change, IPCC, says sea levels rose between 10 and 20cm worldwide during the 20th Century.
It predicts a further rise of between 9cm and 88cm by 2100.Graph: BBC |
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 According to the International Panel on Climate Change, IPCC, North Pole sea-ice has thinned by 40% in recent decades in summer and autumn.
Global snow cover has shrunk by 10% since the 1960s and mountain glaciers have also retreated.Graph: BBC |
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 Most mainstream scientists believe that increased emissions of greenhouse cases, particularly carbon dioxide, are contributing to the warming of the planet.
This graph shows how carbon dioxide levels have increased as the world has industrialised.Graph: BBC |
Published on Wednesday, February 22, 2006 by CommonDreams.org<
Hotter, Faster, Worser
by John Atcheson
Over the past several months, the normally restrained voice of science has taken on a distinct note of panic when it comes to global warming.
How did we go from debating the "uncertainty" behind climate science to near hysterical warnings from normally sober scientists about irrevocable and catastrophic consequences?
Two reasons.
First, there hasn’t been any real uncertainty in the scientific community for more than a decade.
An unholy alliance of key fossil fuel corporations and conservative politicians have waged a sophisticated and well-funded misinformation campaign to create doubt and controversy in the face of nearly universal scientific consensus.
In this, they were aided and abetted by a press which loved controversy more than truth, and by the Bush administration, which has systematically tried to distort the science and silence and intimidate government scientists who sought to speak out on global warming.
But the second reason is that the scientific community failed to adequately anticipate and model several positive feedback loops that profoundly amplify the rate and extent of human-induced climate change.
And in the case of global warming, positive feedback loops can have some very negative consequences.
The plain fact is, we are fast approaching — and perhaps well past — several tipping points which would make global warming irreversible.
In an editorial in the Baltimore Sun on December 15th, 2004 this author outlined one such tipping point: a self-reinforcing feedback loop in which higher temperatures caused methane — a powerful heat-trapping greenhouse gas (GHG) — to escape from ice-like structures called clathrates, which raised the temperature which caused more methane to be released and so on.
Even though there was strong evidence that this mechanism had contributed to at least two extreme warming events in the geologic past, the scientific community hadn’t yet focused on methane ices in 2004.
Even among the few pessimists who had, we believed — or hoped — that we had a decade or so before anything like it began happening again.
We were wrong.
In August of 2005 a team of scientists from Oxford and Tomsk University in Russia announced that a massive Siberian peat bog the size of Germany and France combined was melting, releasing billions of tons of methane as it did.
The last time it got warm enough to set off this feedback loop was 55 million years ago in a period known as the Paleocene-Eocene Thermal Maximum or PETM, when increased volcanic activity released enough GHGs to trigger a series of self-reinforcing methane burps.
The resulting warming caused massive die-offs and it took more than a 100,000 years for the earth to recover.
It’s looks like we’re on the verge of triggering a far worse event.
At a recent meeting of the American Academy for the Advancement of Sciences in St. Louis, James Zachos, foremost expert on the PETM reported that greenhouse gasses are accumulating in the atmosphere at thirty times the speed with which they did during the PETM.
We may have just witnessed the first salvo in what could prove to be an irreversible trip to hell on earth.
There are other positive feedback loops we’ve failed to anticipate.
For example, the heat wave in Europe that killed 35,000 people in 2003 also damaged European woodlands, causing them to release more carbon dioxide, the main GHG, than they sequester — exactly the opposite of the assumptions built into our models, which treat forests as sponges that sop up excess carbon.
The same thing is happening to a number of other ecosystems that our models and scientists have treated as carbon sinks.
The Amazon rainforest, the boreal forests (one of the largest terrestrial carbon sinks in the planet), and soils in temperate areas are all releasing more carbon than they are absorbing, due to global warming-induced droughts, diseases, pest activity, and metabolic changes.
In short, many of the things we treat as carbon sponges in our models aren’t sopping up excess carbon; they’re being wrung out and releasing extra carbon.
The polar ice cap is also melting far faster than models predict, setting off another feedback loop.
Less ice means more open water, which absorbs more heat which means less ice, and so on.
Even worse, we’ve substantially underestimated the rate at which continental glaciers are melting.
Climate change models predicted that it would take more than 1,000 years for Greenland’s ice sheet to melt.
But at the AAAS meeting in St. Louis, NASA’s Eric Rignot outlined the results of a study that shows Greenland’s ice cover is breaking apart and flowing into the sea at rates far in excess of anything scientists predicted, and it’s accelerating each year.
If (or when) Greenland’s ice cover melts, it will raise sea levels by 21 feet — enough to inundate nearly every sea port in America.
In the Antarctic seas, another potentially devastating feedback loop is taking place.
Populations of krill have plummeted by 80% in the last few years due to loss of sea ice.
Krill are the single most important species in the marine foodchain, and they also extract massive amounts of carbon out of the atmosphere.
No one predicted their demise, but the ramifications for both global warming and the health of marine ecosystems are disastrous.
This, too, will likely feed on itself, as less krill means more carbon stays in the atmosphere, which means warmer seas, which means less ice, which means less krill and so on in a massive negative spiral.
One of our preeminent planetary scientists, James Lovelock, believes that in the not too distant future humans will be restricted to a relatively few breeding pairs in Antarctica.
It would be comfortable to dismiss Professor Lovelock as a doom and gloom crazy, but that would be a mistake.
Spit on our bones and curse our names
A little over a year ago at the conclusion of a global conference in Exeter England on Avoiding Dangerous Climate Change, scientists warned that if we allowed atmospheric concentrations of GHG to exceed 400 ppm, we could trigger serious and irreversible consequences.
We passed that milestone in 2005 with little notice and no fanfare.
The scientific uncertainty in global warming isn’t about whether it’s occurring or whether it’s caused by human activity, or even if it will "cost" us too much to deal with it now.
That’s all been settled.
Scientists are now debating whether it’s too late to prevent planetary devastation, or whether we have yet a small window to forestall the worst effects of global warming.
Our children may forgive us the debts we’re passing on to them, they may forgive us if terrorism persists, they may forgive us for waging war instead of pursuing peace, they may even forgive us for squandering the opportunity to put the nuclear genie back in the bottle.
But they will spit on our bones and curse our names if we pass on a world that is barely habitable when it was in our power to prevent it.
And they will be right to do so.
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 This map, from the UK’s Hadley Centre, assumes that current emissions trends continue, with moderate economic growth and few measures to reduce emissions.
It predicts the greatest rises in northern polar regions, India, Africa and parts of South America.
Some scientists believe that as permafrost organic matter becomes exposed to the air it will accelerate global warming faster than even predicted in the most pessimistic forecasts.Graph: BBC |
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For archive purposes, this article is being stored on TheWE.cc website.The purpose is to advance understandings of environmental, political, human rights, economic, democracy, scientific, and social justice issues. |
The amount of carbon trapped in some types of permafrost — called yedoma — is much more prevalent than originally thought and may be 100 times the amount of carbon released into the air each year by the burning of fossil fuels
When you start messing around with these natural systems, you can end up in situations where it's unstoppable
