Methane clathrates and runaway warming


in Economics, Science, The environment

Terraces de la Chaudière

Essentially a form of ice infused with methane, clathrates may seem an obscure topic for discussion. They exist only under extreme conditions: such as underneath oceanic sediment. What makes them significant is the sheer volume of methane they contain. While it is unclear what degree of warming would be required to induce methane release from clathrates, there is a very real possibility that such release could be self-reinforcing. Given the global warming potential of methane and the volume of the gas in oceanic clathrates, such a self-sustaining release could induce abrupt and massive climatic change.

As a greenhouse gas, methane is potent. Averaged across a 100 year span, one tonne of methane produces as much warming as 25 tonnes of carbon dioxide. Even worse, when atmospheric methane breaks down, it generally oxidizes into carbon dioxide and water. Taking into account secondary effects, the warming potential of a tonne of methane is about equal to 72 tonnes of CO2 (according to the Fourth assessment report of the IPCC). This is one reason people are so concerned about the climatic effects of meat production, as well as the reason for which methane capture projects are one of the more credible kinds of carbon offset.

Recent estimates hold that ocean clathrates contain 500-2500 gigatonnes of carbon dioxide equivalent: akin to 100-500 years worth of sustainable emissions. About 400 Gt of carbon dioxide equivalent is in the Arctic permafrost. If a substantial proportion of this methane were to be released, it would take the world into completely unknown climatic territory. As such, it is highly likely that the adaptive capacity of both humanity and existing ecosystems would be overwhelmed, perhaps to a degree akin to the Permian-Triassic extinction event. This is truly the nightmare scenario for climate change, though its probability cannot be accurately assessed in relation to any combination of human behaviours and natural variations.

The existence of such exceedingly dire possibilities affects economic calculations about climate change. While it may not be sensible to spend 20% of global GDP to avoid an outcome with a 0.1% chance of occurring, a strong argument can be made that heavy expenditure is justified in the face of catastrophic risk. It is not as though we have another planet to fall back on if this one gets rendered unfit for human habitation.

[Update: 4 February 2009] Here is a post on the danger of self-amplifying, runaway climate change: Is runaway climate change possible? Hansen’s take.

[Update: 19 February 2010] See also: The threat from methane in the North.

Report a typo or inaccuracy

{ 15 comments… read them below or add one }

. November 24, 2007 at 9:51 am

Methane-Eating Bacteria Could Combat Global Warming

By Zonk on now-just-need-to-work-on-oil-eating-bugs

realwx writes “New Zealand scientists have found a bacterium, named ‘Methylokorus infernorum,’ that eats a key global warming chemical. Found in a hot spring, the bug lives off of methane emissions from geothermically active areas. A scientist quoted in the article stated that a cubic meter of liquid containing the bacterium would consume about 11kg of methane each year. ‘But Dr Stott cautioned that such an application was probably some years into the future. He said it was unlikely the micro-organism, which prefers acidic conditions of about 60C, could ever be added to sheep or cows’ food to stop the animals releasing methane.'”

. November 24, 2007 at 10:01 am

PM Howard concedes Australia poll

In Asia-Pacific

Australian PM John Howard concedes election victory to Labor, and looks set to lose his own seat.

. November 25, 2007 at 3:54 am

There is no imputus for leaders to act on 100 year, or even 50 year impacts. Leaders will be dead in 20-40 years. Leaders will no longer be leaders in 2 to 10 years. Voters will no longer be voters in 20-50 years (voting under age 30 is slim).

Why should people act in other peoples interests? And even if they could, there exists no system to enforce world emissions reduction. I don’t see how climate change could be averted except through world eco-fascism.

. November 26, 2007 at 11:39 am

Canada assailed over climate change

“My understanding is that there is pretty much unanimous agreement except for Canada and Australia, but Canada is the major objector,” said a well-placed Commonwealth government source, adding that he was surprised by the “vehemence” of the Canadian position.

“It’s not a casual position,” the source continued. “It’s a strong personal view of Harper himself.”

. November 26, 2007 at 11:45 am

Five Commandments, Stephen Harper style

“Go-for-it” Prime Minister Stephen Harper told Commonwealth leaders on the weekend that Canada won’t bind itself to climate regulation until the poorest and most destitute countries on the planet sign up first.

Imagining how liberating it might be to apply this policy position to traditional areas of government, here are five updated commandments that we might expect soon from Canada’s me-last Prime Minister, Stephen Harper.

1. Steal in good conscience until the last, most-wretched and disenfranchised street person agrees to stop stealing first.

2. Kill at will until you get a sworn statement from Osama bin Laden, Moqtada as-Sadr and the U.S. Joint Chiefs of Staff saying that they have switched, irrevocably and for all time, to the path of peace.

3. Lie outrageously until Bill Clinton tells the whole story about the dress, Senator Larry Craig comes clean on what really happens in airport men’s rooms and former Canadian Prime Minister Brian Mulroney fesses up about the cash payments from international influence peddler Karl-Heinz Schreiber.

4. Covet they neighbor’s house until the global real estate industry stops advertising.

5. Fornicate frequently, and with whomever you choose, until the global dictates of love, lust and human nature are repealed.

But why stop there? Take off that helmet. Unstrap that seatbelt. Drive when you’re drunk. In short, from now on, the mission statement of all Harper-led Canadians can be:

“Hey, everybody else is doin’ it.”

If only adolescence had been this much fun ..

. November 27, 2007 at 11:10 am

The Other Greenhouse Gases
Is methane really worse for the environment than carbon dioxide?

The one sliver of good news is that methane emissions seem to be leveling off. According to Environment Canada, atmospheric methane concentrations should permanently stabilize if we cut our current methane output by a seemingly manageable 8 percent. As a consumer, you can help a minuscule amount by reducing the amount of waste you send to landfills. But the most promising solutions aren’t on the end-user level. The Lantern mentioned one such remedy a few weeks back: capturing methane from landfills and then using it to generate electricity or to supply gas-hungry industrial operations. In the agricultural realm, those cow burps can be made less methane-rich by fiddling with the animals’ diets; Australian scientists contend, for example, that adding cottonseed oil to livestock feed can reduce each cow’s methane emissions by up to 30 percent. (The typical cow belches forth about a third of a pound of methane per day.)

But some environmentalists worry that such ingenious technological solutions will come to naught, given the consequences of rising temperatures on the world’s cold spots. There’s lots of methane stored in the permafrost that covers much of northern Canada and Siberia, and that gas would be released should appreciable melting occur.

. April 28, 2008 at 2:51 pm

Burning ice, ice, baby
Methane hydrates: What’s the worst — and best — that could happen?

. April 28, 2008 at 2:51 pm

A recent workshop on methane hydrates felt like a powwow of 19th century California gold prospectors, looking ahead to both riches and peril. Sizing up the prize, Arthur Johnson, a veteran geologist of the oil industry who is now an energy consultant based in Kenner, Louisiana, predicted that “within a decade or two, hydrates will grow to 10 to 15 percent of natural gas production,” becoming a more than $200 billion industry. And the peril? “The worst-case scenario is that global warming triggers a decade-long release of hundreds of gigatons of methane, the equivalent of 10 times the current amount of greenhouse gas in the atmosphere,” said David Archer, a climate modeler at the University of Chicago in Illinois. Although no current model predicts such an event, said Archer, “we’d be talking about mass extinction.”

. July 8, 2008 at 11:20 am
. September 2, 2008 at 11:40 am

All the energy America needs for the next 100 years lies under the sea off the coast of South Carolina. One problem: Digging it out could cause a global climate disaster.

Welcome to the final frontier in fossil fuels, the wild card in climate change theories and the dark horse in the scramble to secure access to clean energy. Meet methane hydrates, the world’s most promising and perilous energy resource.

. September 30, 2008 at 2:08 pm

Yesterday, researchers on board the British research ship the James Clark Ross said they had counted about 250 methane plumes bubbling from the seabed in an area of about 30 square miles in water less than 400 metres (1,300 feet) deep off the west coast of Svalbard. They have also discovered a set of deeper plumes at depths of about 1,200 metres at a second site near by. Analysis of sediments and seawater has confirmed the rising gas is methane, said Professor Graham Westbrook of Birmingham University, the study’s principal investigator.

The discovery of this system is important as its presence provides evidence that methane, which is a greenhouse gas, has been released in this climactically sensitive region since the last ice age,” Professor Westbrook said. An analysis of sediments taken from the seabed show that the gas is coming from methane hydrates – ice-like crystals where molecules of the gas are captured in “cages” made of water molecules, which become unstable as water pressures fall or temperatures rise.

. April 23, 2009 at 5:31 pm

Study rules out ancient bursts of seafloor methane emissions
Published: Thursday, April 23, 2009 – 13:38 in Earth & Climate

Measurements made from the largest Greenland ice sample ever analyzed have confirmed that an unusual rise in atmospheric methane levels about 12,000 years ago was not the result of a catastrophic release of seafloor “hydrate deposits,” as some scientists had feared. The findings, to be published Friday in the journal Science, are good news for those who have worried that this unusual mechanism of releasing methane into the atmosphere might provide a serious reinforcement to global warming at some point in the future.

It now appears almost certain that the major methane increases that occurred near the end of the last Ice Age were due to the growth of wetlands and the methane releases associated with that, which occurred shortly after some significant warming in the Northern Hemisphere. They did not come from sudden bursts of methane trapped in deep seafloor deposits.

. January 26, 2011 at 6:12 pm

Toxic Ash Clouds Might Be Culprit in Biggest Mass Extinction
by Sid Perkins on 23 January 2011, 1:00 PM

Tiny particles embedded in ancient Canadian rocks have provided new clues about what might have triggered Earth’s deadliest mass extinction. The ultimate cause, researchers say, might be globe-smothering clouds of toxic ash similar to that spewed by modern-day coal-fired power plants.

The die-off, which occurred worldwide about 250 million years ago at the end of the Permian period, was even more extensive than the one that wiped out the dinosaurs. More than 90% of marine species went extinct, and land-based ecosystems suffered almost as much. Scientists have long debated the reasons. Favorite hypotheses include an asteroid impact, massive volcanic eruptions in Siberia, and toxic oceans. Geochemist Stephen Grasby of the Geological Survey of Canada in Calgary and colleagues report online today in Nature Geoscience a new twist on the volcano notion.

Rocks that now make up the northernmost islands of the Canadian Arctic formed millions of years ago as seafloor sediments off the northwestern coast of a supercontinent called Pangaea. When Grasby and his team analyzed rocks from just before the Permian mass extinction, they noticed unusual microscopic particles. Besides the usual miniscule clumps of organic matter, they also found tiny bubble-filled particles called cenospheres. These frothy little blobs form only when molten coal spews into the atmosphere, the researchers say. Today, the fly ash produced by coal-fired power plants brims with cenospheres, but they are largely trapped by pollution-control equipment before they escape the smokestack. Millions of years ago, they must have been created when massive amounts of molten rock—more than 1 trillion metric tons—erupted through overlying coal deposits in Siberia to form lava deposits known as the Siberian Traps.

. August 5, 2011 at 4:23 pm

By analysing the isotopic composition of hydrocarbon molecules from plant waxes of the period, he found what looks like a spike in the amount of recently non-biological carbon (which has a distinctive ratio of light isotopes to heavy ones), lasting between 10,000 and 20,000 years. He thinks the liberation of methane stored at the bottom of the ocean in structures called clathrates is the most likely culprit. The alternative, that the carbon came from the volcanoes, is unlikely because the spike is much shorter than the period of volcanic activity. Methane is a greenhouse gas far stronger than carbon dioxide, so the consequence would have been a rapid warming of the climate—a phenomenon that the rocks suggest did actually happen.

This is not the first time a methane burp has been blamed for an extinction. Though the Cretaceous asteroid cleared the stage, mammals did not really get going until 10m years later, in the Eocene epoch. The preceding Palaeocene epoch was also brought to an end, the rocks suggest, by a sudden release of methane.

The burp could, of course, have been provoked by the eruptions, so the volcanoes are not off the hook completely. But, for those of a nervous disposition, the tying of an ancient greenhouse warming to an ancient mass extinction might suggest lessons for the future.

. December 10, 2014 at 2:17 pm

Warmer Pacific Ocean could release millions of tons of seafloor methane

Off the West Coast of the United States, methane gas is trapped in frozen layers below the seafloor. New research from the University of Washington shows that water at intermediate depths is warming enough to cause these carbon deposits to melt, releasing methane into the sediments and surrounding water. Researchers found that water off the coast of Washington is gradually warming at a depth of 500 meters, about a third of a mile down. That is the same depth where methane transforms from a solid to a gas. The research suggests that ocean warming could be triggering the release of a powerful greenhouse gas.

Leave a Comment

You can use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

{ 1 trackback }

Previous post:

Next post: