January 9, 2012
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Editors note: This is a condensed version of a post that originally appeared on RealClimate.org
It’s the unknown that grabs attention.
We don’t know the total amount of methane frozen deep beneath the ocean, but we suspect it could rival the rest of fossil fuels combined. And we don’t know how much is frozen in the Arctic’s thawing permafrost and lake sediments.
We do know those methane deposits are seeping into the atmosphere, however. And the possibility of a catastrophic release is of, course, what gives methane its power over the imagination. Journalists in particular seem susceptible to doomsday predictions from such a scenario.
We have seen methane bubbling from the sea floor in the Arctic. Lakes provide an escape path for the methane by creating “thaw bulbs” in the underlying soil, and lakes are everywhere appearing and disappearing in the Arctic as the permafrost melts.
Yet so far we haven’t seen ironclad evidence of greater methane releases due to anthropogenic warming, though such an event is certainly believable for the coming century. This brings us to the key question: What effect would a methane release have on climate?
The impact depends on whether methane is released all at once or in an ongoing, sustained manner.
Let’s pick the most likely scenario: A slow ongoing release.
Methane is a powerful greenhouse gas, trapping 72 times the amount of heat per molecule in the short term compared to carbon dioxide but “burning” to CO2 in the atmosphere in about a decade. We suspect large stores of methane, known as methane hydrates, lie frozen at the bottom of ever-warming oceans, particularly in the Arctic. On land, decomposing organic matter in thawing permafrost is another potential methane source.
I’ve modeled what happens if that methane is released continually for several decades: The atmospheric impact from methane itself only persists for about a decade beyond the methane release, whereas the extra CO2 in the atmosphere persists throughout the simulation of 100,000 years.
The possibility of a catastrophic release is more remote, but it’s a subject that, as journalists say, has legs. A submarine landslide might release a gigaton of carbon as methane, but the effect of that would be small, about equal in magnitude to – but opposite in effect of – a volcanic eruption. Detectable, perhaps, but not the end of humankind as a species.
So what could happen to methane in the Arctic?
The methane bubbles coming from the Siberian shelf are part of a system that takes centuries to respond to changes in temperature. The methane from the Arctic lakes is also potentially part of a new, enhanced, chronic methane release to the atmosphere. Neither of them could release a catastrophic amount of methane – hundreds of gigatons – within a short time-frame of a few years or less. There isn’t some huge bubble of methane waiting to erupt as soon as its roof melts.
And so far, the sources of methane from high latitudes are small, relative to the big players: wetlands in warmer climes and human emissions. It is very difficult to know whether the bubbles are a brand-new methane source caused by global warming, or a response to warming that has happened over the past 100 years, or whether plumes like this happen all the time. In any event, it doesn’t matter very much unless they get 10 or 100 times larger, because high-latitude sources are small compared to the tropics.
So maybe by century’s end, perhaps 2,000 gigatons of carbon could be released into the atmosphere by humans burning fossil fuels and other activities under some sort of business-as-usual scenario. And we might see another 1,000 gigatons of carbon from soil and methane hydrate release, as a worst case.
Can we get some sort of a doomsday, runaway greenhouse effect scenario from that?
I tweaked my models to try. If the methane hydrates released too much carbon, say two carbons from hydrates for every one carbon from fossil fuels, on a time scale that was too fast – say 1,000 years instead of 10,000 years – the system could run away. But the fact that ice core and sediment records do not seem full of methane spikes makes it seem like the real world is not as sensitive as we were able to set the model up to be.
On the other hand, the deep ocean could ultimately – after a thousand years or so – warm up by several degrees in the business-as-usual scenario, making it warmer than it has been in millions of years. It takes millions of years to grow the hydrates; they have had time to grow in response to Earth’s relative cold of the past 10 million years or so. Also, the climate is very sensitive to changes in CO2 when its concentration is low, as it is today relative to what it was 50 million of years ago.
In short, if there was ever a good time to provoke a hydrate meltdown it would be now. But “now” is in a geological sense, thousands of years into the future, not really “now” in a human sense. Thawing methane hydrates in the ocean and permafrost peats could be a significant multiplier of the long tail of the carbon dioxide, but it will probably not be a huge player in climate change in the coming century.
The real point of no return in this adventure is our ongoing release of carbon dioxide.
The only way back to a natural climate in anything like our lifetimes would be to physically extract carbon dioxide from the atmosphere. The carbon dioxide that has been absorbed into the oceans would degas back to the atmosphere to some extent, so we’d have to clean that up too.
And if methane hydrates or permafrost peats contributed some extra carbon into the mix, that would also have to be part of the bargain, like paying interest on a loan.
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Interesting article.
I generally agree with your statement:
“The only way back to a natural climate in anything like our lifetimes would be to physically extract carbon dioxide from the atmosphere. The carbon dioxide that has been absorbed into the oceans would degas back to the atmosphere to some extent, so we’d have to clean that up too.”
However, I suggest that “back to a natural climate” should be further qualified, such as ‘any state approximating a natural climate.’ Without wordplay, there is no way that simply sequestering co2 would likely approximate an environment that might have existed if the industrial revolution had never occurred and the human population had not increased from 1-2 billion to >7 billion. Moreover, I suspect that any method of artificially sequestering co2 might be subject to catastrophic release in unforeseen future conditions…
Link to thisCurrent climate models don’t take into consideration melting methane hydrate emissions, which will soon overwhelm any cuts we make:
For instance, there is an area six times the size of Germany containing about 540 billion tons of carbon off the Siberian coast. That submarine permafrost is perilously close to thawing. Three to 12 kilometers from the coast the sea sediment is just below freezing. The permafrost has grown porous, there is a loss of rigor in the frozen sea floor, and the surrounding seawater is highly oversaturated with solute methane.
“If the Siberian (submarine) permafrost-seal thaws completely and all the stored gas escapes, the methane content of the planet’s atmosphere would increase twelve fold. The result would be catastrophic global warming.” –”A Storehouse of Greenhouse Gases Is Opening in Siberia,” Spiegel, 17 April ’08
NASA’s top climate scientist, James Hansen, says that the release of methane clathrates from permafrost regions and beneath the seabed will unleash powerful feedback forces that could produce runaway climate change that cannot be controlled – the so-called methane time bomb – a prediction of radical environmental transformation far worse than the worst-case scenarios theorised by the UN’s Intergovernmental Panel on Climate Change.
BTW: There is a new clean energy technology that is one tenth the cost of coal. LENR using nickel. Incredibly: Ni+H(heated under pressure)=Cu+lots of heat. This phenomenon (LENR) has been confirmed in hundreds of published scientific papers: http://lenr-canr.org/acrobat/RothwellJtallyofcol.pdf
“Over 2 decades with over 100 experiments worldwide indicate LENR is real, much greater than chemical…” –Dennis M. Bushnell, Chief Scientist, NASA Langley Research Center
“Energy density many orders of magnitude over chemical.” Michael A. Nelson, NASA
“Total replacement of fossil fuels for everything but synthetic organic chemistry.” –Dr. Joseph M. Zawodny, NASA
Link to thisNot to argue, but it would have been much clearer if you’d explained that you were referring to cold fusion.
When were your quoted statements by NASA personnel made?
As stated in http://en.wikipedia.org/wiki/LENR
“The ISI identified cold fusion as the scientific topic with the largest number of published papers in 1989, of all scientific disciplines. The number of papers sharply declined after 1990 as scientists abandoned the controversy and journal editors declined to review new papers, and cold fusion fell off the ISI charts.”
While wikipeddia is not an authoritive reference, this entry does include 185 references to more authoritive sources.
The number of scientific research reports published during a brief period is not a meaningful gauge of a technology’s viability. I think that no economically large scale device has ever been demonstrated and that without large scale investments none are forthcoming.
To be blunt, the deceptive nature of your comment is troubling to me.
Link to thisNice fiction.
A couple of problems
1. If methane “traps” heat energy photons, first does that mean that the methane is forever at a temperature greater than the surroundings and the laws of heat transfer do not apply so that it can not transfer heat to colder surroundings? and is forever hotter and can NOT come to equilinrium in violation of accepted laws of heat transfer (Just how did it get cold in the first place? )and second Why is it that cold methane in the solid artic canNOT absorb IR photons to warm up , and even colder methane in the upper atmosphere CAN absorb heat photons to “trap” energy? Are you saying that the greenhouse effect (absorpion & transfer of an energy photon)does not work in solids (ice) but only in gases? Or that there are no IR photons in ice to provide a GHE energy when underground? Either way you have just said the laws of physics and heat transfer do not apply to methane or Greenhouse gases.
2, I contend thsat the Greenhouse effect, is a simple heat transfer mechanism just like convection and conduction. It takes energy the from of a photon at a local point, radiates it out (towards colder space) as IR to where it is absorbed & transferred to the surrounding air (95%) by collisions and 5% by futher transmission out eventually to space. Just where exactly is there an increase or warming? IF there is no increase in available energy photons for absorption then the extra CO2 or methane can NOT participate in an increased GHE. (Of course you could claim it creates the energy in violation of Newton’s concept that energy can not be created or destroyed.) IT will just sit there, like water does as excess. It is the number of energy photons, not the number of GHG atoms (methane or CO2) that dictates the temperature. By counting the heat in the GHE you are double counting total system energy in your computer programs. You don’t count the heat energy in convection or conduction do you?
Maybe you should be looking for added sources of energy to account for the very real increase in temperature since the 70s, since the amount of solar insolation (E/M energy) has been essentially constant since then. Maybe you should look at the paper “Gravity causes climate change” in http://www.scribd,com. It explains why Gravity the 4th force cyclically transfers energy to Earth, depending upon the location of the sun and planets (Mostly Jupiter)
Link to thisWhile you are at it, maybe you can explain why the the Earth’s decay heat (from breaking the long and short force bonds in atoms) which is supposed to be 50% of the Earth’s heat energy, and is combined with the bouncing solar insolation (E/M) energy to create the IR for the GHE is totally ignored by climate science and IPCC?
Fossil fuels are just
Link to thisFossil fuels are just too damn expensive already anyways. And the pollution causing millions of deaths per year. Let’s give up on being children, pathetic creatures who are too stupid, corrupt and weak to embrace what James Lovelock calls “the natural energy of the universe” – Nuclear Energy.
Canada, the USA and Russia had a race to the North Pole a few years ago. Canada & the USA with their top-of-the-line best-ever diesel powered icebreakers. Russia with one of their Nuclear Powered icebreakers. It was no contest, both Canada & the USA got stuck in the ice, while the Russia Nuclear Powered easily zoomed through the ice to the North Pole. That is a telling example of the difference between fossil fuels and Nuclear Energy. Just the word Nuclear sends shivers of fear through Big Oil lobbyists.
check out this video on one of the ten Russian Nuclear Power Icebreakers.
http://tinyurl.com/2doo92y
Crashing through Ice at speed requires a huge amount of energy, Canada & the USA’s diesel powered icebreakers are a PATHETIC JOKE compared to this Russian Nuclear Powered Icebreaker. It travels at 15 knots for one day through 6 ft of ice on ONE POUND of Uranium. Canada & the USA’s diesel powered Icebreakers cannot do a fraction of that consuming 100 tons of smoke belching fuel every day. They need a bloody Oil Tanker to keep them running.
From the Video:
“…crashing through ice 10 ft thick, and to see her 25,000 tons roaring along @ 20 knots, it is hard not to be staggered by the Nuclear Fires in this Ship’s belly…”
Link to thisThanks to JT for the clarification on the sneaky cold fusion post. My only response to this whole methane issue is; let us capture and burn it to generate electricity. Release the CO2 and let the plants grow.
Link to this