Top Scientists Speak Out On Growing Risk of Methane Emergency

With the Arctic warming so rapidly, risk of a large methane release is a considerable and growing problem. Estimates are that more than 2,000 gigatons of the stuff lay trapped in northern hemisphere permafrost or locked in methane stores called clathrates on the bottom of the shallow Arctic Ocean. As human caused climate change drives rapid sea ice retreat, the ocean warms and mechanical action mixes the water, transporting more and more heat down to the seabed, destabilizing the frozen methane. As the snow line retreats in the warming climate, more permafrost is also laid bear, amplifying the release of land-based methane stores.

On the East Siberian Arctic shelf, a vulnerable region of the Arctic Ocean, perhaps 500 gigatons of methane and methane clathrate rest on or just beneath the sea bed. If just 1% of the  methane store in this single region were released, atmospheric methane would double.

Over the past few years, growing evidence has been accumulated that methane emissions from the Arctic permafrost and seabed are increasing. The East Siberian Arctic shelf produced vast methane emitting formations as large as 1 kilometer in diameter during 2011. Such releases are a potential sign of growing destabilization in the region. And since any major release of Arctic methane would provide a catastrophic amplifying feedback to human caused global warming, concern is growing that we are at increasing risk for just such an event.

In the above video, James Hansen, head of NASA’s GISS division, Natalia Shakhova, a scientist at the International Arctic Research Center, Peter Wadhams, a Professor at Cambridge and resident Arctic sea ice expert, and David Wasdell, a prominent environmentalist, discuss the dangers of Arctic methane release. Hansen and Wadhams are both very heavy hitters and bear listening to. Shakhova is doing cutting-edge research in the field and serves as a witness to the dangerous trend that is unfolding. And Wasdell rounds the discussion out by providing the ecological and climate context in which a large methane release may occur.

The problem is certainly very, very serious and we urgently need to reduce carbon emissions to reduce the risk of a large and catastrophic release.

To follow atmospheric methane, take a look at NOAA’s carbon gasses tracker at Barrow Alaska (CO2, methane, CFCs, etc):

http://www.esrl.noaa.gov/gmd/dv/iadv/graph.php?code=BRW&program=ccgg&type=ts

Links:

https://robertscribbler.wordpress.com/2012/10/26/human-co2-emissions-continue-to-play-russian-roulette-with-clathrate-gun-new-study-shows-east-coast-hydrates-destabilizing/

http://neven1.typepad.com/blog/

http://neven1.typepad.com/files/overshooting-limits-gwj.doc

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Human CO2 Emissions Continue to Play Russian Roulette with Clathrate Gun: New Study Shows East Coast Methane Hydrates Destabilizing

According to a new study published in the journal Nature, increasing ocean temperatures combined with changes in the structure of the Gulf Stream are causing the rapid destabilization of large amounts of methane off the US East Coast. What the study shows is that the Gulf Stream is getting warmer due to human-caused global warming and that the warmth is pushing deeper and deeper into the ocean. As the warmer waters encounter the Continental Shelf they begin to affect massive frozen reserves of methane called methane hydrates or clathrates on the sea bed.

Clathrates are a frozen combination of methane and water. The substance is very unstable and, once disturbed, can rapidly transition from its frozen state to methane gas. Hundreds of gigatons of methane lie trapped in clathrate in the region affected by the Gulf Stream. If even a fraction of these clathrates were to destabilize, it could result in a powerful amplifying feedback to global warming, ocean and atmospheric anoxia (oxygen loss) and worse.

The study postulates that ocean warming of 5 degrees Celsius may have caused a massive release of methane about 50 million years ago resulting in a large release of methane that caused both wide-spread ocean acidification and a major increase of about 5-7 degrees Celsius in world temperatures. The sea bed in the region in question is  shown to have warmed by about 8 degrees Celsius since the last ice age with rapid warming occurring since the advent of human greenhouse gas emissions.

The study found than an area of 10,000 square kilometers off the East Coast showed rapidly destabilizing clathrates. The total volume at immediate risk of destabilization was 2.5 gigatons. Because methane is many times as potent as carbon dioxide, a single release of methane of the size estimated would triple or quadruple the amount of heat forcing produced by human greenhouse gas emissions in one year. Futhermore, this study focused only on the US East Coast as a potential methane source. Other studies have found large methane releases coming from the Alaskan Continental Shelf, the East Siberian Arctic Shelf, and other regions of the Arctic. This was the first major mid-latitude study and it is also likely that vulnerable methane deposits exist in other continental shelf zones around the world.

In total, the East Coast methane store of about 300-500 gigatons of methane clathrate adds to another 1000-1400 gigatons of Arctic clathrate, 1000+ gigatons of methane stored in permafrost and at least 100 gigatons of methane stored beneath Antarctica. This total contains more carbon than all the world’s remaining conventional fossil fuels and has a very large potential to greatly enhance human-caused warming. Furthermore, unknown amounts of methane hydrate lie in wait in other world ocean regions.

Continued human CO2 emission creates an added forcing that is likely to increase the risk of a large methane release from frozen permafrost and from clathrates. It has been hypothesized that large releases of this kind caused a major temperature spike and mass extinction in the ocean about 50 million years ago. A larger release of methane about 250 million years ago called the Permian extinction event is thought to have caused a major die off of 96 percent of ocean species.

Russian Arctic researcher Shakhova has estimated that it is possible for as much as 50 gigatons of Arctic methane to be released in single large events called pulses. Such large events, if they were to occur, would have terrible regional, local, global and oceanic impacts. Large regions of the ocean would be stripped of oxygen. The local atmosphere, as well, would be at risk of becoming anoxic. Areas where atmospheric concentration of methane exceeded 5% (5000 ppm) would be at risk of severe firestorms.

But even a more gradual release of the methane would be devastating, causing an amplifying feedback to human CO2 emission that could raise world temperatures by as much as 18 degrees Fahrenheit by the end of this century. The difference between Shakhova’s large pulse and the more gradual release expected by other scientists is the difference between a flash fire or a slow bake. But the end result is the same — a world that really isn’t livable for human beings or for many other creatures either.

The Recent changes to the Gulf Stream causing widespread gas hydrate destabilization study shows that the Arctic Ocean is no longer the only region of concern for rapid methane release due to human climate forcings. Now, the Eastern Continental Shelf of the United States is shown to contain a substantial methane reserve and that 2.5 gigatons of this methane is undergoing rapid destabilization. And all of these studies, when taken into context show that continued human greenhouse gas emission is a severe and unconscionable risk. Each year, as more of these gasses enter the atmosphere, there is more and more risk of a catastrophic methane release event. Each year, as the heat builds up, we are at greater risk of entering an age when the heat content of the atmosphere is so great that large methane releases continue to occur for centuries and may result in a world that is devastated and unlivable for humans.

So for each year that we continue to emit CO2 we continue to play a game of Russian Roulette with the largest weapon on the planet — the Clathrate Gun. We know the bullet is in the chamber. We have found evidence for it in the Arctic, the Antarctic and now just off the US East Coast. But we don’t quite know whether this year’s trigger pull of another 30+ gigatons of human CO2 emission will spark a series of unstoppable and terrible events. Or if it will be next year. Or the year after.

Only one thing is certain. If we pull the trigger enough, that terrible gun is bound to go off. The best course of action is to stop pulling the CO2 trigger. To put the gun down and step away from the burning of fossil fuels which have become so very dangerous.

Links:

http://www.nature.com/nature/journal/v490/n7421/full/nature11528.html?WT.ec_id=NATURE-20121025

http://en.wikipedia.org/wiki/Clathrate_gun_hypothesis

https://robertscribbler.wordpress.com/2012/03/18/arctic-sea-ice-melt-methane-release-shows-amplifying-feedbacks-from-human-caused-climate-change/

http://www.skepticalscience.com/Wakening_the_Kraken.html

Arctic Sea Ice Melt, Methane Release Shows Amplifying Feedbacks from Human Caused Climate Change

For years now, scientists have warned that additional atmospheric heat caused by human releases of carbon dioxide (CO2) could result in amplifying feedbacks that cause even more heat. At first, most of these comments were academic, an exercise in predicting what would happen if humans did not curtail greenhouse gas emissions. But as human CO2 emissions continued to increase, global warming amplified and changes accelerated. Now the warnings from scientists are much more direct. Consider NASA scientist James Hansen’s most recent statement:

“We don’t have a substantial cushion between today’s climate and dangerous warming. Earth is poised to experience strong amplifying feedbacks in response to moderate additional global warming.” – James Hansen

Amplifying Feedbacks via Microphone

An amplifying feedback is a rapidly increasing response to an initial forcing. In everyday life, people are generally familiar with what happens when you put a microphone close to a speaker. The microphone picks up ambient noise, and pushes it out through the speaker. This, now louder, noise is picked up again by the microphone and sent back to the speaker as a much louder input. The loop continues until the speaker is pouring out a rapidly rising wail of sound.

Arctic Sea Ice Melt as Amplifying Feedback

In nature, something very similar can happen as a result of an initial climate forcing. In the Arctic, we can see this in the form of sea ice melt over the past few decades. Increases in ocean temperature and stored heat has gradually worn away at both Arctic sea ice area and Arctic sea ice volume.

In 2007, Arctic sea ice area reached the lowest levels ever recorded, a level far below the 1979-2001 average. Sea ice lost area equal to 20% of the total summer coverage of the previous year. More than 20% of Arctic sea ice gone in one year. Since that time, Arctic sea ice area has failed to recover with 2011 showing the second lowest area on record at end of summer, an area very close to the unprecedented 2007 record low.

Image

The above image shows the difference between 1980 and 2007 Arctic sea ice (Source: Cryosphere Today).

But sea ice area as seen from above only tells half the story. The second half is told by total sea ice volume. Area measures how much surface is covered by ice. Volume measures the total amount of ice by taking into account sea ice thickness. And when looking at volume, there has been a precipitous and unrelenting fall.

Image

Sea Ice Volume shown above is calculated using data from the Pan-Arctic Ice Ocean Modeling and Assimilation System of the Applied Physics Lab at the Polar Science Center and inserting it into a curve fitting process. And the curve shows a near-ice free Arctic under current trends by or before the summer of 2020. In fact, the model shows that September could see ice-free seas as early as 2013. Not likely, but another couple summers like 2007 could bring us very close.

But even if current trends don’t hold, additional statistical analysis shows nearly ice free summers by or before 2035.

And the, usually guarded, IPCC findings point toward ice-free summers before 2050. So depending on the dynamics of Arctic weather, which can certainly be very dynamic, our best analysis points toward a continuation of rapid collapse or a shift to a more gradual melt down.

Regardless of final melt dates, APL sea ice volume measurements show Arctic sea ice is getting very, very thin.

The reason Arctic sea ice melt is an amplifying feedback is due to the heat reflective nature of ice vs the heat absorption nature of water. Water just by virtue of color alone, absorbs more sunlight than ice. This results in water temperature in ice free seas being as much as 5 degrees C warmer than water beneath sea ice. And this warmer water heats both the air and the entire water column. Loss of sea ice alone is a powerful amplifier of temperatures during the Arctic summer and this extra absorbed heat is on top of the extra heat added by human caused global warming via CO2 emissions.

Arctic Methane Releases as Amplifying Feedback

It is the nature of single amplifying feedbacks that they tend to kick off other feedbacks. And this is exactly what is happening with Arctic methane.

In the Arctic, both methane and ice have been locked together in a chilly marriage ever since the roof of the world began to freeze about 10 million years ago. The reason for this is that the bodies of dead plants and animals have accumulated in the tundra’s frozen soil year after year. Dead and decayed biological matter has also been locked in formations called methane hydrates in the shallow Arctic sea.

When the ice melts, seas warm. This results in warmer winds blowing over the tundra. The tundra’s permfrost soils begin to melt and, when they do, bacteria begin to break down the dead matter locked in these frozen soils for so long. Once the matter breaks down, methane is released.

Now methane is a very powerful greenhouse gas — packing a potency twenty times that of CO2. So Arctic methane releases result in a powerful global warming force adding to the effects of sea ice melt and human CO2 emissions. The result is that the Arctic warms even more, more tundra melts, and more methane is released.

Image

Often, when heat melts the tundra, new lakes form. These lakes contain large volumes of methane. Sometimes, researchers ignite this methane to demonstrate how much is being emitted from the lakes. Often, these ignitions result in dramatic plumes of fire, illustrating the explosive nature of methane emissions in the Arctic.

But, sometimes, this new methane seeping up from Arctic soils are ignited by nature in the form of lightning strikes. And these lightning strikes can result in vast tundra fires that burn massive swaths of the Arctic. One such tundra fire recently burned an area the size of Cape Cod in Alaska.

Image

These tundra fires convert massive volumes of biological matter into CO2 which adds another amplifying feedback.

Out Gassing of Submerged Arctic Methane

Even though vast areas of land are now providing amplifying feedbacks as Arctic tundra thaws, some of the thawing tundra isn’t on land, it’s under the water. North of Siberia, the East Siberian Arctic Shelf (ESAS) is a protrusion of tundra now flooded by the Arctic Ocean. As the water above this shallow shelf warmed, the submerged tundra began to thaw, and as it thawed it began to release methane.

These underwater methane releases were only recently discovered. Since their discovery, the rate of methane release has defied all expectations, pouring more methane into the atmosphere than any other natural source. Just this summer, Arctic researchers including Igor Semiletov discovered enormous plumes of methane venting up from the sea bed. According to the researchers, some of these methane plumes were more than 1 kilometer across.

“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 in a 2011 interview. “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.”

Some of this submerged methane comes from the decomposition of submerged tundra, the rest comes in the form of destabilized methane hydrates. As seen on the map below, the ESAS is just one of many areas where high concentrations of methane hydrate are expected.

Overall, 1700 gigatons of carbon are estimated to be locked up in the melting tundra and more than 4400 gigatons of carbon are estimated to be stored in the form of methane hydrates. By comparison, remaining conventional fossil fuel sources are estimated to contain about 1100 gigatons of carbon — about equal to the amount already emitted. So even if a fraction of Arctic Methane destabilizes it could more than double the impacts of human caused climate change.

But there is additional danger. They include loss of oxygen in the world’s oceans, rapidly increasing ocean acidification, the risk of much larger tundra fires, and the risk of very large fires sparked by lightning strikes in the event of sudden, large methane releases. These dangers should be seen as directly related to the risk posed by amplifying feedbacks.

Combined Impacts

When added to the very high volumes of CO2 produced by human activity, a volume 150 times that produced yearly by volcanoes, the increased heating caused by melting sea ice and increased methane release creates a dangerous amplifying feedback to global warming. The effects of these feedbacks are large and growing larger. The valid concern among scientists and those researching climate change is that these feedbacks will only expand exponentially as human forcing increases, eventually creating a cascade of effects whose scale is beyond the ability of humans to reign in.

Sources:

Cryosphere Today: http://arctic.atmos.uiuc.edu/cryosphere/

National Snow and Ice Data Center: http://nsidc.org/arcticseaicenews/

The Polar Science Center: http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/

“Vast Plumes of Methane Seen in Arctic as Sea Ice Retreats” http://www.independent.co.uk/news/science/vast-methane-plumes-seen-in-arctic-ocean-as-sea-ice-retreats-6276278.html

International Arctic Research Center: http://www.iarc.uaf.edu/en/about

The Storms of My Grandchildren by James Hansen, 2008

 

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