I wrote about The Independent's previous article on the subject, and Iain Stewart's final part of Earth - The Climate Wars, here:
Methane Gas: The Great Escape (24 September 2008)
Methane Gas: The Great Escape (24 September 2008)
Methane And Global Warming
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ramonmercado
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Not sure if i should say Strewth! or Fair Dinkum Cobber!
Methane release 'looks stronger'
Scientists have uncovered what appears to be a further dramatic increase in the leakage of methane gas that is seeping from the Arctic seabed.
Methane is about 20 times more potent than CO2 in trapping solar heat.
The findings come from measurements of carbon fluxes around the north of Russia, led by Igor Semiletov from the University of Alaska at Fairbanks.
"Methane release from the East Siberian Shelf is underway and it looks stronger than it was supposed [to be]," he said.
Professor Semiletov has been studying methane seepage in the region for the last few decades, and leads the International Siberian Shelf Study (ISSS), which has launched multiple expeditions to the Arctic Ocean.
The preliminary findings of ISSS 2009 are now being prepared for publication, he told BBC News.
Methane seepage recorded last summer was already the highest ever measured in the Arctic Ocean.
High seepage
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.
This undersea permafrost was until recently considered to be stable.
But now scientists think the release of such a powerful greenhouse gas may accelerate global warming.
Higher concentrations of atmospheric methane are contributing to global temperature rise; this in turn is projected to cause further permafrost melting and the release of yet more methane in a feedback loop.
A worst-case scenario is one where the feedback passes a tipping point and billions of tonnes of methane are released suddenly, as has occurred at least once in the Earth's past.
Such sudden releases have been linked to rapid increases in global temperatures and could have been a factor in the mass extinction of species.
According to a report by the US National Oceanic and Atmospheric Administration (Noaa), the springtime air temperature across the region in the period 2000-2007 was an average of 4C higher than during 1970-1999.
That is the fastest temperature rise on the planet, claims the university.
The recent thaw over the last decade means that some of the large reserve of carbon from organic material such as dead animals and plants in sediments is now being released into the sea and into our atmosphere.
Trapped below that is the methane hydrate now warming and leaking through holes in the defrosting sediments.
Previously it was thought much of this gas was absorbed into the sea.
But according to a recent report that Professor Semiletov and his team compiled for the environmental group WWF, the shallow depth of arctic shelves means that methane is reaching the atmosphere without reacting to become CO2 dissolved in the ocean.
Professor Semiletov's fellow researcher aboard the Russian icebreaker that carries the ISSS team each year is Professor Orjan Gustafsson from Stockholm University in Sweden.
He said that methane measured in the atmosphere around the region is 100 times higher than normal background levels, and in some cases 1,000 times higher.
'No alarm'
Despite the high readings, Professor Gustafsson said that so far there was no cause for alarm, and stressed that further studies were still necessary to determine the exact cause of the methane seepage.
"It is important now to understand how fast it is being released and how much is being released," he said.
However, there is a real fear that global warming may cause Siberia's subsea permafrost to thaw.
Some estimates put the amount of carbon trapped in shelf permafrost at 1,600 billion tonnes - roughly twice as much carbon as in the atmosphere now.
The release of this once captive carbon from destabilised ocean sediments and permafrost would have catastrophic effect on our climate and life on Earth, warn the scientists.
http://news.bbc.co.uk/1/hi/sci/tech/8437703.stm
The italics are mine. i think everyone who reads this thread knows my *general* position on the matter, but those statistics seem unbelievable to me. which bit of the "air" was being tested here? Once published officially it will be an absolute field day for the mass media...
Scientists have uncovered what appears to be a further dramatic increase in the leakage of methane gas that is seeping from the Arctic seabed.
Methane is about 20 times more potent than CO2 in trapping solar heat.
The findings come from measurements of carbon fluxes around the north of Russia, led by Igor Semiletov from the University of Alaska at Fairbanks.
"Methane release from the East Siberian Shelf is underway and it looks stronger than it was supposed [to be]," he said.
Professor Semiletov has been studying methane seepage in the region for the last few decades, and leads the International Siberian Shelf Study (ISSS), which has launched multiple expeditions to the Arctic Ocean.
The preliminary findings of ISSS 2009 are now being prepared for publication, he told BBC News.
Methane seepage recorded last summer was already the highest ever measured in the Arctic Ocean.
High seepage
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.
This undersea permafrost was until recently considered to be stable.
But now scientists think the release of such a powerful greenhouse gas may accelerate global warming.
Higher concentrations of atmospheric methane are contributing to global temperature rise; this in turn is projected to cause further permafrost melting and the release of yet more methane in a feedback loop.
A worst-case scenario is one where the feedback passes a tipping point and billions of tonnes of methane are released suddenly, as has occurred at least once in the Earth's past.
Such sudden releases have been linked to rapid increases in global temperatures and could have been a factor in the mass extinction of species.
According to a report by the US National Oceanic and Atmospheric Administration (Noaa), the springtime air temperature across the region in the period 2000-2007 was an average of 4C higher than during 1970-1999.
That is the fastest temperature rise on the planet, claims the university.
The recent thaw over the last decade means that some of the large reserve of carbon from organic material such as dead animals and plants in sediments is now being released into the sea and into our atmosphere.
Trapped below that is the methane hydrate now warming and leaking through holes in the defrosting sediments.
Previously it was thought much of this gas was absorbed into the sea.
But according to a recent report that Professor Semiletov and his team compiled for the environmental group WWF, the shallow depth of arctic shelves means that methane is reaching the atmosphere without reacting to become CO2 dissolved in the ocean.
Professor Semiletov's fellow researcher aboard the Russian icebreaker that carries the ISSS team each year is Professor Orjan Gustafsson from Stockholm University in Sweden.
He said that methane measured in the atmosphere around the region is 100 times higher than normal background levels, and in some cases 1,000 times higher.
'No alarm'
Despite the high readings, Professor Gustafsson said that so far there was no cause for alarm, and stressed that further studies were still necessary to determine the exact cause of the methane seepage.
"It is important now to understand how fast it is being released and how much is being released," he said.
However, there is a real fear that global warming may cause Siberia's subsea permafrost to thaw.
Some estimates put the amount of carbon trapped in shelf permafrost at 1,600 billion tonnes - roughly twice as much carbon as in the atmosphere now.
The release of this once captive carbon from destabilised ocean sediments and permafrost would have catastrophic effect on our climate and life on Earth, warn the scientists.
http://news.bbc.co.uk/1/hi/sci/tech/8437703.stm
The italics are mine. i think everyone who reads this thread knows my *general* position on the matter, but those statistics seem unbelievable to me. which bit of the "air" was being tested here? Once published officially it will be an absolute field day for the mass media...
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More on the spike in the amount of methane escaping from the permafrost, due to higher temperatures in the Arctic, here:
http://www.guardian.co.uk/environment/2010/jan/14/arctic-permafrost-methane
http://www.guardian.co.uk/environment/2010/jan/14/arctic-permafrost-methane
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Methane levels may see 'runaway' rise, scientists warn
A rapid acceleration may have begun in levels of a gas far more harmful than CO2
By Michael McCarthy, Environment Editor
Monday, 22 February 2010
Atmospheric levels of methane, the greenhouse gas which is much more powerful than carbon dioxide, have risen significantly for the last three years running, scientists will disclose today – leading to fears that a major global-warming "feedback" is beginning to kick in.
For some time there has been concern that the vast amounts of methane, or "natural gas", locked up in the frozen tundra of the Arctic could be released as the permafrost is melted by global warming. This would give a huge further impetus to climate change, an effect sometimes referred to as "the methane time bomb".
This is because methane (CH4) is even more effective at retaining the Sun's heat in the atmosphere than CO2, the main focus of international climate concern for the last two decades. Over a relatively short period, such as 20 years, CH4 has a global warming potential more than 60 times as powerful as CO2, although it decays more quickly.
Now comes the first news that levels of methane in the atmosphere, which began rising in 2007 when an unprecedented heatwave in the Arctic caused a record shrinking of the sea ice, have continued to rise significantly through 2008 and 2009.
Although researchers cannot yet be certain, and there may be non-threatening explanations, there is a fear that rising temperatures may have started to activate the positive feedback mechanism. This would see higher atmospheric levels of the gas producing more warming, which in turn would release more methane, which would produce even further warming, and so on into an uncontrollable "runaway" warming effect. This is believed to have happened at the end of the last Ice Age, causing a very rapid temperature rise in a matter of decades.
The new figures will be revealed this morning at a major two-day conference on greenhouse gases in the atmosphere, taking place at the Royal Society in London. They will be disclosed in a presentation by Professor Euan Nisbet, of Royal Holloway College of the University of London, and Dr Ed Dlugokencky of the Earth System Research Laboratory in Boulder, Colorado, which is run by the US National Oceanic and Atmospheric Administration (NOAA).
etc...
http://www.independent.co.uk/environmen ... 06484.html
A rapid acceleration may have begun in levels of a gas far more harmful than CO2
By Michael McCarthy, Environment Editor
Monday, 22 February 2010
Atmospheric levels of methane, the greenhouse gas which is much more powerful than carbon dioxide, have risen significantly for the last three years running, scientists will disclose today – leading to fears that a major global-warming "feedback" is beginning to kick in.
For some time there has been concern that the vast amounts of methane, or "natural gas", locked up in the frozen tundra of the Arctic could be released as the permafrost is melted by global warming. This would give a huge further impetus to climate change, an effect sometimes referred to as "the methane time bomb".
This is because methane (CH4) is even more effective at retaining the Sun's heat in the atmosphere than CO2, the main focus of international climate concern for the last two decades. Over a relatively short period, such as 20 years, CH4 has a global warming potential more than 60 times as powerful as CO2, although it decays more quickly.
Now comes the first news that levels of methane in the atmosphere, which began rising in 2007 when an unprecedented heatwave in the Arctic caused a record shrinking of the sea ice, have continued to rise significantly through 2008 and 2009.
Although researchers cannot yet be certain, and there may be non-threatening explanations, there is a fear that rising temperatures may have started to activate the positive feedback mechanism. This would see higher atmospheric levels of the gas producing more warming, which in turn would release more methane, which would produce even further warming, and so on into an uncontrollable "runaway" warming effect. This is believed to have happened at the end of the last Ice Age, causing a very rapid temperature rise in a matter of decades.
The new figures will be revealed this morning at a major two-day conference on greenhouse gases in the atmosphere, taking place at the Royal Society in London. They will be disclosed in a presentation by Professor Euan Nisbet, of Royal Holloway College of the University of London, and Dr Ed Dlugokencky of the Earth System Research Laboratory in Boulder, Colorado, which is run by the US National Oceanic and Atmospheric Administration (NOAA).
etc...
http://www.independent.co.uk/environmen ... 06484.html
ramonmercado
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Shock as retreat of Arctic sea ice releases deadly greenhouse gas
Russian research team astonished after finding 'fountains' of methane bubbling to surface
Steve Connor Tuesday 13 December 2011
Dramatic and unprecedented plumes of methane – a greenhouse gas 20 times more potent than carbon dioxide – have been seen bubbling to the surface of the Arctic Ocean by scientists undertaking an extensive survey of the region.
The scale and volume of the methane release has astonished the head of the Russian research team who has been surveying the seabed of the East Siberian Arctic Shelf off northern Russia for nearly 20 years.
In an exclusive interview with The Independent, Igor Semiletov, of the Far Eastern branch of the Russian Academy of Sciences, said that he has never before witnessed the scale and force of the methane being released from beneath the Arctic seabed.
"Earlier we found torch-like structures like this but they were only tens of metres in diameter. This is the first time that we've found continuous, powerful and impressive seeping structures, more than 1,000 metres in diameter. It's amazing," Dr Semiletov said. "I was most impressed by the sheer scale and high density of the plumes. Over a relatively small area we found more than 100, but over a wider area there should be thousands of them."
Scientists estimate that there are hundreds of millions of tonnes of methane gas locked away beneath the Arctic permafrost, which extends from the mainland into the seabed of the relatively shallow sea of the East Siberian Arctic Shelf. One of the greatest fears is that with the disappearance of the Arctic sea-ice in summer, and rapidly rising temperatures across the entire region, which are already melting the Siberian permafrost, the trapped methane could be suddenly released into the atmosphere leading to rapid and severe climate change.
Dr Semiletov's team published a study in 2010 estimating that the methane emissions from this region were about eight million tonnes a year, but the latest expedition suggests this is a significant underestimate of the phenomenon.
In late summer, the Russian research vessel Academician Lavrentiev conducted an extensive survey of about 10,000 square miles of sea off the East Siberian coast. Scientists deployed four highly sensitive instruments, both seismic and acoustic, to monitor the "fountains" or plumes of methane bubbles rising to the sea surface from beneath the seabed.
"In a very small area, less than 10,000 square miles, we have counted more than 100 fountains, or torch-like structures, bubbling through the water column and injected directly into the atmosphere from the seabed," Dr Semiletov said. "We carried out checks at about 115 stationary points and discovered methane fields of a fantastic scale – I think on a scale not seen before. Some plumes were a kilometre or more wide and the emissions went directly into the atmosphere – the concentration was a hundred times higher than normal."
Dr Semiletov released his findings for the first time last week at the American Geophysical Union meeting in San Francisco
http://www.independent.co.uk/environmen ... 76134.html
Russian research team astonished after finding 'fountains' of methane bubbling to surface
Steve Connor Tuesday 13 December 2011
Dramatic and unprecedented plumes of methane – a greenhouse gas 20 times more potent than carbon dioxide – have been seen bubbling to the surface of the Arctic Ocean by scientists undertaking an extensive survey of the region.
The scale and volume of the methane release has astonished the head of the Russian research team who has been surveying the seabed of the East Siberian Arctic Shelf off northern Russia for nearly 20 years.
In an exclusive interview with The Independent, Igor Semiletov, of the Far Eastern branch of the Russian Academy of Sciences, said that he has never before witnessed the scale and force of the methane being released from beneath the Arctic seabed.
"Earlier we found torch-like structures like this but they were only tens of metres in diameter. This is the first time that we've found continuous, powerful and impressive seeping structures, more than 1,000 metres in diameter. It's amazing," Dr Semiletov said. "I was most impressed by the sheer scale and high density of the plumes. Over a relatively small area we found more than 100, but over a wider area there should be thousands of them."
Scientists estimate that there are hundreds of millions of tonnes of methane gas locked away beneath the Arctic permafrost, which extends from the mainland into the seabed of the relatively shallow sea of the East Siberian Arctic Shelf. One of the greatest fears is that with the disappearance of the Arctic sea-ice in summer, and rapidly rising temperatures across the entire region, which are already melting the Siberian permafrost, the trapped methane could be suddenly released into the atmosphere leading to rapid and severe climate change.
Dr Semiletov's team published a study in 2010 estimating that the methane emissions from this region were about eight million tonnes a year, but the latest expedition suggests this is a significant underestimate of the phenomenon.
In late summer, the Russian research vessel Academician Lavrentiev conducted an extensive survey of about 10,000 square miles of sea off the East Siberian coast. Scientists deployed four highly sensitive instruments, both seismic and acoustic, to monitor the "fountains" or plumes of methane bubbles rising to the sea surface from beneath the seabed.
"In a very small area, less than 10,000 square miles, we have counted more than 100 fountains, or torch-like structures, bubbling through the water column and injected directly into the atmosphere from the seabed," Dr Semiletov said. "We carried out checks at about 115 stationary points and discovered methane fields of a fantastic scale – I think on a scale not seen before. Some plumes were a kilometre or more wide and the emissions went directly into the atmosphere – the concentration was a hundred times higher than normal."
Dr Semiletov released his findings for the first time last week at the American Geophysical Union meeting in San Francisco
http://www.independent.co.uk/environmen ... 76134.html
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rynner2 said:
Not a surprise. These reseachers must be easily "shocked".
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Although methane has been found rising from the sea floor before, I think the 'shocking' element here is the sheer volume discovered,SHAYBARSABE said:
A 1,000m diameter seeper could release 10,000 times the volume of methane released by a 10m diameter seeper if the flow rates per square metre are similar.
The other 'shocking' aspect is that this methane release seems to have been triggered by the ongoing GW, and this creates a positive feedback reinforcing GW, possibly leading to a catastrophic runaway effect.
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Expect methane levels in the UK to rise significantly this Christmas due to the consumption of Brussels sprouts. 
kamalktk
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rynner2 said:
I guess I come from the point of view that we know the methane is down there. We know that warming can release it. Volume just doesn't seem shocking--unless they mean shocking in the absolutely terrifying sense. (Yes, I did see "Dimming the Sun" which now seems to be available in parts on youtube.com -- http://youtu.be/gUD66kjLVNw)
ramonmercado
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Interesting proposals. Chart & images at link.
Mythopoeika
I am a meat popsicle
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If methane is rising to the surface, I don't know why we aren't harvesting it on a large scale. It seems to me that mining clathrates would be a lot easier than drilling for gas.
In fact, if it was mined on a big enough scale, natural gas could be used as a relatively green alternative to oil, for the purposes of producing fuel for vehicles.
In fact, if it was mined on a big enough scale, natural gas could be used as a relatively green alternative to oil, for the purposes of producing fuel for vehicles.
ramonmercado
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Mythopoeika said:
Good point. anyone know if there is a method of harvesting it available?
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Arctic melt releasing ancient methane
By Richard Black, Environment correspondent, BBC News
Scientists have identified thousands of sites in the Arctic where methane that has been stored for many millennia is bubbling into the atmosphere.
The methane has been trapped by ice, but is able to escape as the ice melts.
Writing in the journal Nature Geoscience, the researchers say this ancient gas could have a significant impact on climate change.
Methane is the second most important greenhouse gas after CO2 and levels are rising after a few years of stability.
There are many sources of the gas around the world, some natural and some man-made, such as landfill waste disposal sites and farm animals.
Tracking methane to these various sources is not easy.
But the researchers on the new Arctic project, led by Katey Walter Anthony from the University of Alaska at Fairbanks (UAF), were able to identify long-stored gas by the ratio of different isotopes of carbon in the methane molecules.
Using aerial and ground-based surveys, the team identified about 150,000 methane seeps in Alaska and Greenland in lakes along the margins of ice cover.
Local sampling showed that some of these are releasing the ancient methane, perhaps from natural gas or coal deposits underneath the lakes, whereas others are emitting much younger gas, presumably formed through decay of plant material in the lakes.
"We observed most of these cryosphere-cap seeps in lakes along the boundaries of permafrost thaw and in moraines and fjords of retreating glaciers," they write, emphasising the point that warming in the Arctic is releasing this long-stored carbon.
"If this relationship holds true for other regions where sedimentary basins are at present capped by permafrost, glaciers and ice sheets, such as northern West Siberia, rich in natural gas and partially underlain by thin permafrost predicted to degrade substantially by 2100, a very strong increase in methane carbon cycling will result, with potential implications for climate warming feedbacks."
Quantifying methane release across the Arctic is an active area of research, with several countries despatching missions to monitor sites on land and sea.
The region stores vast quantities of the gas in different places - in and under permafrost on land, on and under the sea bed, and - as evidenced by the latest research - in geological reservoirs.
"The Arctic is the fastest warming region on the planet, and has many methane sources that will increase as the temperature rises," commented Prof Euan Nisbet from Royal Holloway, University of London, who is also involved in Arctic methane research.
"This is yet another serious concern: the warming will feed the warming."
How serious and how immediate a threat this feedback mechanism presents is a controversial area, with some scientists believing that the impacts will not be seen for many decades, and others pointing out the possibility of a rapid release that could swiftly accelerate global warming.
http://www.bbc.co.uk/news/science-environment-18120093
By Richard Black, Environment correspondent, BBC News
Scientists have identified thousands of sites in the Arctic where methane that has been stored for many millennia is bubbling into the atmosphere.
The methane has been trapped by ice, but is able to escape as the ice melts.
Writing in the journal Nature Geoscience, the researchers say this ancient gas could have a significant impact on climate change.
Methane is the second most important greenhouse gas after CO2 and levels are rising after a few years of stability.
There are many sources of the gas around the world, some natural and some man-made, such as landfill waste disposal sites and farm animals.
Tracking methane to these various sources is not easy.
But the researchers on the new Arctic project, led by Katey Walter Anthony from the University of Alaska at Fairbanks (UAF), were able to identify long-stored gas by the ratio of different isotopes of carbon in the methane molecules.
Using aerial and ground-based surveys, the team identified about 150,000 methane seeps in Alaska and Greenland in lakes along the margins of ice cover.
Local sampling showed that some of these are releasing the ancient methane, perhaps from natural gas or coal deposits underneath the lakes, whereas others are emitting much younger gas, presumably formed through decay of plant material in the lakes.
"We observed most of these cryosphere-cap seeps in lakes along the boundaries of permafrost thaw and in moraines and fjords of retreating glaciers," they write, emphasising the point that warming in the Arctic is releasing this long-stored carbon.
"If this relationship holds true for other regions where sedimentary basins are at present capped by permafrost, glaciers and ice sheets, such as northern West Siberia, rich in natural gas and partially underlain by thin permafrost predicted to degrade substantially by 2100, a very strong increase in methane carbon cycling will result, with potential implications for climate warming feedbacks."
Quantifying methane release across the Arctic is an active area of research, with several countries despatching missions to monitor sites on land and sea.
The region stores vast quantities of the gas in different places - in and under permafrost on land, on and under the sea bed, and - as evidenced by the latest research - in geological reservoirs.
"The Arctic is the fastest warming region on the planet, and has many methane sources that will increase as the temperature rises," commented Prof Euan Nisbet from Royal Holloway, University of London, who is also involved in Arctic methane research.
"This is yet another serious concern: the warming will feed the warming."
How serious and how immediate a threat this feedback mechanism presents is a controversial area, with some scientists believing that the impacts will not be seen for many decades, and others pointing out the possibility of a rapid release that could swiftly accelerate global warming.
http://www.bbc.co.uk/news/science-environment-18120093
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There was a picture to go with that story.rynner2 said:
No doubt, you could light some of those streams of bubbles, like enormous farts.
An article from January, this year, from the Real Climate website.
More, including the full links, references and comments, at the site.
Don't panic, just don't expect too much good news.
AngelAlice
bemused & saddened observer
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rynner2 said:
Okay, but if Black was being impartial he'd have to tell his readers why this is so 'controversial' - which is because many scientists doubt there will be any positive feedback at all. Positive feedback loops occur infrequently in nature and there is as yet no evidence whatsoever that climate works like that. He should also have added that if there is indeed no positive feedback, then the theory of runaway heating is brought into major question - as it is based almost solely on the assumption that positive feedback will definitely happen.
Again - just trying to offer the all-important balance.
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Antarctic may host methane stores
Large volumes of methane - a potent greenhouse gas - could be locked beneath the ice-covered regions of Antarctica, according to a new study.
It says this methane could be released into the atmosphere as ice retreats, contributing to climate warming.
The findings indicate that ancient deposits of organic matter may have been converted to methane by microbes under the ice.
An international team reported the results in Nature journal.
Study leader Jemima Wadham, from Bristol University, said: "This is an immense amount of organic carbon, more than ten times the size of carbon stocks in northern permafrost regions.
"Our laboratory experiments tell us that these sub-ice environments are also biologically active, meaning that this organic carbon is probably being metabolised to carbon dioxide and methane gas by microbes."
They estimate that there could be hundreds of billions of tonnes of carbon stored in methane reservoirs under the ice sheet.
The authors say that the predicted shallow depth of these methane reserves means that they could be destabilised by climate change, and might act as a positive feedback on global warming.
Co-author Dr Sandra Arndt, also from the University of Bristol, said: "It's not surprising that you might expect to find significant amounts of methane hydrate trapped beneath the ice sheet.
"Just like in sub-seafloor sediments, it is cold and pressures are high which are important conditions for methane hydrate formation."
In their Nature paper, the authors comment that their "findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget".
http://www.bbc.co.uk/news/science-environment-19410444
Large volumes of methane - a potent greenhouse gas - could be locked beneath the ice-covered regions of Antarctica, according to a new study.
It says this methane could be released into the atmosphere as ice retreats, contributing to climate warming.
The findings indicate that ancient deposits of organic matter may have been converted to methane by microbes under the ice.
An international team reported the results in Nature journal.
Study leader Jemima Wadham, from Bristol University, said: "This is an immense amount of organic carbon, more than ten times the size of carbon stocks in northern permafrost regions.
"Our laboratory experiments tell us that these sub-ice environments are also biologically active, meaning that this organic carbon is probably being metabolised to carbon dioxide and methane gas by microbes."
They estimate that there could be hundreds of billions of tonnes of carbon stored in methane reservoirs under the ice sheet.
The authors say that the predicted shallow depth of these methane reserves means that they could be destabilised by climate change, and might act as a positive feedback on global warming.
Co-author Dr Sandra Arndt, also from the University of Bristol, said: "It's not surprising that you might expect to find significant amounts of methane hydrate trapped beneath the ice sheet.
"Just like in sub-seafloor sediments, it is cold and pressures are high which are important conditions for methane hydrate formation."
In their Nature paper, the authors comment that their "findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget".
http://www.bbc.co.uk/news/science-environment-19410444
ramonmercado
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Warming ocean temperatures a third of a mile below the surface, in a dark ocean in areas with little marine life, might attract scant attention. But this is precisely the depth where frozen pockets of methane 'ice' transition from a dormant solid to a powerful greenhouse gas.
New University of Washington research suggests that subsurface warming could be causing more methane gas to bubble up off the Washington and Oregon coast.
The study, to appear in the journal Geochemistry, Geophysics, Geosystems, shows that of 168 bubble plumes observed within the past decade, a disproportionate number were seen at a critical depth for the stability of methane hydrates.
"We see an unusually high number of bubble plumes at the depth where methane hydrate would decompose if seawater has warmed," said lead author H. Paul Johnson, a UW professor of oceanography. "So it is not likely to be just emitted from the sediments; this appears to be coming from the decomposition of methane that has been frozen for thousands of years."
Methane has contributed to sudden swings in Earth's climate in the past. It is unknown what role it might contribute to contemporary climate change, although recent studies have reported warming-related methane emissions in Arctic permafrost and off the Atlantic coast.
Of the 168 methane plumes in the new study, some 14 were located at the transition depth - more plumes per unit area than on surrounding parts of the Washington and Oregon seafloor.
http://phys.org/print364044017.html
New University of Washington research suggests that subsurface warming could be causing more methane gas to bubble up off the Washington and Oregon coast.
The study, to appear in the journal Geochemistry, Geophysics, Geosystems, shows that of 168 bubble plumes observed within the past decade, a disproportionate number were seen at a critical depth for the stability of methane hydrates.
"We see an unusually high number of bubble plumes at the depth where methane hydrate would decompose if seawater has warmed," said lead author H. Paul Johnson, a UW professor of oceanography. "So it is not likely to be just emitted from the sediments; this appears to be coming from the decomposition of methane that has been frozen for thousands of years."
Methane has contributed to sudden swings in Earth's climate in the past. It is unknown what role it might contribute to contemporary climate change, although recent studies have reported warming-related methane emissions in Arctic permafrost and off the Atlantic coast.
Of the 168 methane plumes in the new study, some 14 were located at the transition depth - more plumes per unit area than on surrounding parts of the Washington and Oregon seafloor.
http://phys.org/print364044017.html
kamalktk
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Cthlatrates or however they are spelled. People do talk about methane, as in the potential melting of subsea methane ice causing massive amounts of methane to be released.
Also cow farts, yes, people do talk about cow farts methane contribution, and there is research going on into making cows less farty. [Farty being the technical term
]
Mythopoeika
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Yes...there is talk...but no 'methane tax'! Not that I want to pay a methane tax!Cthlatrates or however they are spelled. People do talk about methane, as in the potential melting of subsea methane ice causing massive amounts of methane to be released.
Also cow farts, yes, people do talk about cow farts methane contribution, and there is research going on into making cows less farty. [Farty being the technical term
Yet CO2 is all the climatologists think is important (probably because it's easier to measure it, and therefore easier to tax it). And as a result, we now have yet another money market (carbon trading) for fat cats to dabble in.
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New Zealand attempted to introduce a livestock emissions tax - largely aimed at methane emissions - as early as 2003, but it was mocked out of consideration ...
https://en.wikipedia.org/wiki/Agricultural_emissions_research_levy
Per unit amount, methane in the atmosphere serves to trap far more heat than CO2. I've seen estimates of the differential as high as 80-something to 1 (methane to CO2).
However, there are issues of scale which have an effect on policy priorities.
First, the amount of C02 emitted annually dwarfs the amount of methane. Recent US emissions estimates put the difference in the vicinity of 8 to 1 (CO2 to methane).
For example, see:
https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks
Second, the dissipation / breakdown of atmospheric methane is considerably faster than for CO2. The average duration or latency of CO2 molecules in the atmosphere is similarly circa 8 times that of methane molecules.
The combination of these facts render methane a lesser cause for concern than CO2 (with respect to the 'big picture'), and less of an immediate problem than its greater heat trapping capability (in and of itself) would suggest.
Another factor concerns ambiguities in how effectively methane emissions could be monitored / tracked.
The greatest single source of methane emissions is fossil fuel extraction (coal and petroleum) rather than cow belches. A lot of the output is simply leakage from the natural gas supply chain. In the USA the combination of fossil fuel extraction / leakage and landfill emissions accounts for over 60% of estimated methane emissions. Livestock belches / farts and manure decomposition account for less than 25%.