Guest post by Indur M. Goklany
In the earlier post reporting on the recent greening of the Arctic, some commentators — Crispin in Waterloo, BillD, Jimbo — have alluded to the notion that Arctic thawing could lead to positive feedback by adding to methane emissions to the atmosphere.
This global warming bogeyman is founded on the plausible notion — plausible, at least at first blush — that warming might release methane from methane clathrates (or hydrates) stored in the Arctic permafrost which would increase its concentration in the atmosphere.
But methane has a “global warming potential” averaged over 100 years of 25, that is, methane, ton-for-ton, is 25 times more powerful a greenhouse gas than carbon dioxide (AR4WG1 Technical Summary: 33). Thus, such releases of methane would constitute a positive feedback for global warming.
The initial concerns about methane stemmed from the fact that by the 1990s the atmospheric concentration of methane, which had been growing rapidly, had exceeded 1,730 parts per billion (ppb), almost twice the maximum amount measured over the past 650,000 years in ice cores (AR4WG1: 3).
Concern of runaway methane feedback was also stoked by a number of modeling studies which suggested rapid disintegration of the permafrost with global warming (e.g., Lawrence and Slater 2005, Zimov et al. 2006). However, in a modeling study which took into consideration the thermal profile of the permafrost, and the fact that the melting effect of warm air surface temperatures on the upper layers of permafrost would be countered by cooling due to colder deeper layers of permafrost, Delisle (2007) showed that “massive releases of methane in the near future are questionable.”
Even more compelling is that the growth in atmospheric concentrations has slowed substantially. As noted by the IPCC AR4WG1 (p. 796):
Recent measurements show that CH4 growth rates have declined and were negative for several years in the early 21st century … The observed rate of increase of 0.8 ppb yr–1 for the period 1999 to 2004 is considerably less than the rate of 6 ppb yr–1 assumed in all the [IPCC] SRES scenarios for the period 1990 to 2000.”
The latest observations indicate that the rate of change is not increasing, and that they “are not consistent with sustained changes … yet” (Dlugokencky et al. 2009: 4). [Dlugokencky’s “yet” seems gratuitous — no matter, I’ll give it a pass.] They also indicate that the geographical pattern and the isotopic signature of methane increases suggests that the major sources are wetlands — probably tropical wetlands —rather than Arctic permafrost.
Petrenko et al. (2009) examined the source of isotopic methane in a glacial ice core from West Greenland to determine the probable source of the large increase in methane during the abrupt warming of +10±4°C that occurred during the transition from the Younger Dryas to the Preboreal (~11,600 years ago) (Grachev and Severinghaus 2005). They concluded that “wetlands were the likely main driver of the [methane] increase and that clathrates did not play a large role,” a finding they noted “is in agreement with findings from previous ice core CH4 isotopic studies” (Petrenko et al. 2009: 508). This study essentially reiterated the results of another paper by many of the same researchers that appeared in Nature the previous year (Fischer et al. 2008). Notably the Petrenko et al. study’s publication was accompanied by an announcement titled, “Ancient Greenland methane study good news for planet, says CU-Boulder scientist” (Eureka Alert 2009).
So it seems that while methane emissions might increase if there is warming, there is no evidence of catastrophic releases from clathrates.
References
1. The above is, for the most part, extracted from:
Goklany, Indur M. (2009). Trapped Between the Falling Sky and the Rising Seas: The Imagined Terrors of the Impacts of Climate Change. Prepared for University of Pennsylvania Workshop on Markets & the Environment, draft, 13 December 2009.
2. Specific references follow:
AR4WG1 ≡ IPCC’s Fourth Assessment Report for Work Group 1 ≡ IPCC (2007). Climate Change 2007: The Physical Science Basis. Cambridge: Cambridge University Press.
Delisle, G. (2007), Near-surface permafrost degradation: How severe during the 21st century?, Geophys. Res. Lett., 34, L09503, doi:10.1029/2007GL029323.
Dlugokencky, E. J., et al. (2009). Observational constraints on recent increases in the atmospheric CH4 burden. Geophysical Research Letters, 36, L18803, doi:10.1029/2009GL039780.
Eureka Alert. 2009. Ancient Greenland methane study good news for planet, says CU-Boulder scientist. PR announcement, 23 April 2009. Available at http://www.eurekalert.org/pub_releases/2009-04/uoca-agm042109.php.
Fischer, H., Melanie Behrens, Michael Bock, Ulrike Richter, Jochen Schmitt, Laetitia Loulergue, Jerome Chappellaz, Renato Spahni, Thomas Blunier, Markus Leuenberger & Thomas F. Stocker (2008). Changing boreal methane sources and constant biomass burning during the last termination. Nature 452: 864 -865.
Grachev, Alexi M. and Jeffrey P. Severinghaus (2005). A revised +10±4 °C magnitude of the abrupt change in Greenland temperature at the Younger Dryas termination using published GISP2 gas isotope data and air thermal diffusion constants. Quaternary Science Reviews 24 ( 5-6): 513-519.
Lawrence, D. M., and A. G. Slater (2005). A projection of severe nearsurface permafrost degradation during the 21st century, Geophys. Res. Lett., 32, L24401, doi:10.1029/2005GL025080.
Petrenko, Vasilii V.; Andrew M. Smith, Edward J. Brook, Dave Lowe, Katja Riedel, Gordon Brailsford, Quan Hua, Hinrich Schaefer, Niels Reeh, Ray F. Weiss, David Etheridge, and Jeffrey P. Severinghaus. 14CH4 Measurements in Greenland Ice: Investigating Last Glacial Termination CH4 Sources. Science 324: 506-508.
Zimov, S. A., E. A. G. Schuur, and F. S. Chapin III (2006). Permafrost and the global carbon budget, Science, 313, 1612–1613.
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Barrow Alaska’s methane measurements which are the highest and lead the global numbers by a few years, looks to be slowing down again after a brief rise in 2008 and 2009. Still looks to be plateauing at some point in the very near future.
http://www.esrl.noaa.gov/gmd/webdata/ccgg/iadv/graph/brw/brw_ch4_ts_obs_00011.png
650,000 Years in Ice Cores?
I say B.S. What ice core would have existed that many years ago? Where would that be sampled from? When one considers the RATE at which the ice accumulates both in the Northern Hemisphere (say about 6″ per year, Greenland), unless there are periodic melt offs, this would be 350,000′ of ice. I’m IMMEDIATELY suspicious when I hear a number as this. That would be 70 Miles high.
Does anyone apply sanity checks to these “peer reviewed papers”?
Treehugger have been pushing the whol catastrophic Methane release for the last 6 months – that and ocean acidification seem to be the last cards in their hand. Not much of a playbook
The Idsos at their web site. CO2 science and linked on this board, have been probing this for some years. They list a number of papers on the subject.
The general conclusion of which is that this not a simple physical process, the moment the permafrost warms biological processes previously inhibited by the cold also become active with entirely different results and outcomes to those posited by elementary physical models.
As do many other biological mechanisms.
However much computer power you have can neither use simple physical models to predict this kind of thing nor can can you effectually incorporate biological activity into the models in any meaningful way because too little is known about them.
So it isn’t whether the supposedly warming permafrost might release CO2 it is also about how much the biological processes might adsorb it.
Did you imagine that all that CO2 wasn’t bound up there except by biological processes when temperatures were warm enough to allow this?
Kindest Regards
The GAO say 2 billion!!!
White House Should Coordinate Geoengineering Research to Help Fight Climate Change
Published October 30, 2010 | FoxNews.com
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The White House should come up with a strategy for federal research into large-scale intervention in the Earth’s climate system that could help tackle climate change, a new watchdog report concludes.
The Government Accountability Office found in its report more than 50 current studies, totaling slightly more than $100 million, focusing on piecemeal strategies to reverse climate change, but none directly addresses what would happen if adventurous programs on carbon dioxide reduction and solar radiation management were put in place.
“Without a coordinated federal strategy for geoengineering, it is difficult for agencies to determine the extent of relevant research, and policymakers may lack key information to inform subsequent decisions on engineering and existing climate science efforts,” the report said, adding that most of the $2 billion spent each year on federal climate science research could also help geoengineering with better coordination.
Geoengineering either removes carbon dioxide from the atmosphere or offsets temperature increases by reflecting sunlight back into space.
GAO cautioned that these strategies poses some environmental risks that could be hard to contain.
“Major uncertainties remain regarding the scientific, legal, political, economic and ethical implications of researching or deploying geoengineering,” the GAO report read.
The GAO prepared the report for Rep. Bart Gordon, D-Tenn., chairman of the House Committee on Science and Technology.
Erratum
I should have also included methane in the above post.
Kindest Regards
Indur Goklany, I like the way you set the record straight. I also wonder what happens to “methane” in an abrupt warming like Y-D when Earth is impacted by comet break-up debris, as the research seems to strongly suggest. Why don’t those who are in the throes of AGW-Climate Change-Climate Disruption pay attention (with money and studies and preventive measures) to the real dangers to Earth.
So where was this when the vikings farmed there? just askin.
This was the type of conjecture that Popular Science used to have fun with back in the 60/70’s. However since the onset of the scientific dementia of Scientific American, National Geographic, Nature, Science, etc, Popular Science and its unrelated buddy Popular Mechanics have grown up and had to be the parents of the genre. So they don’t publish pure conjecture like this as science anymore unless it is clearly labeled as such.
25% of the current global warming is due to CH4 released by cows. Reduce AGW eat less meat.
CH4 has a half life in the upper atmosphere of less than 7 years. GCR converts CH4 into CO2 and H2. The hydrogen is gradually removed by the solar wind.
The CO2 is deposited on to the surface of the continents or the deep ocean.
The upper layers of the ocean are saturated with CH4 which would indicate the mantel or the core is releasing CH4. (It is the core.) At high latitude locations and in the deep ocean the CH4 that the CH4 accumulates.
Max Hugoson says:
October 30, 2010 at 5:24 pm
650,000 Years in Ice Cores?
I say B.S. What ice core would have existed that many years ago?
Ice cores extend to about 800,000 years. The snow is compressed into ice and the annual layers are rather thin [4000,000 millimeter/800,000 years = 5 millimeters not 6 inches] as also the Arctic/Antarctic are low precipitation areas to boot.
Biomass degrades though biological action. When the temperature warms, bacteria and fungi become more active. Methanogens might have a go, and if there is enough methane, methanotrophs could have an opportunity to grow. If so, methane may be converted to CO2 before it leaves the ground. Given that the atmospheric methane concentration has nearly leveled off, that suggests some form of equilibrium has been established.
Physicists and engineers ignore biology all too often. Biology is such a ‘soft’ science. It’s unfortunate if they have that bias. I’ll tell you, Nature bites you when you get too cocky. I’ve seen it happen (and I smile a quiet little smile).
The problems we face today are partly due to theoreticians giving politicians the credibility they need to set otherwise irrational policy. For example, climate models suck, and policy based on them is dangerous. I don’t mind theoreticians, but at some point they need to validate their theory. Build a better transistor. Make a fusion reactor. Make some tiny black holes. Include the sun and cosmic rays in your climate models (What? That makes climate unpredictable?!! Inconveniently unpredictable.)
And another thing: Too many politicians are lawyers. We need other varieties. Any volunteers? You just need some people skills. And you can’t be from Berkeley.
Where does this 6 inches of accumulation number come from? Considering the huge differences in the amount of snowfall world wide, it sounds like you are the one spouting BS. For example, places in the Antarctic only get a few tenths of an inch of snow per year. Beyond that, ice does not accumulate, snow does. Then as more snow accumulates, the snow gets compressed into ice.
I was not even particularly thinking about methane clathrates (or hydrates). Methane is also produced during anaerobic degredation of the organic matter rich tundra. I don’t have the numbers in hand, but I have read that the tundra is the largest store of dead organic matter that would be converted to CO2 if the ground melts. Another few degrees of warming in the arctic will have a big effect. I expect that the arctic will continue to warm.
Oh, yes, this is a dangerous situation … (chuckle!)
So let’s see: Did said methane releases cause trouble during the two prior major warming periods, i.e., Roman, and MWP?
No? Then what’s the big deal now, even though it’s much cooler than either of those periods?
Max Hugoson says:
October 30, 2010 at 5:24 pm
650,000 Years in Ice Cores?
I say B.S. What ice core would have existed that many years ago? Where would that be sampled from? When one considers the RATE at which the ice accumulates both in the Northern Hemisphere (say about 6″ per year, Greenland), unless there are periodic melt offs, this would be 350,000′ of ice. I’m IMMEDIATELY suspicious when I hear a number as this. That would be 70 Miles high.
Does anyone apply sanity checks to these “peer reviewed papers”?
————–……………………—————-
Apart from ensuring that your comment appears twice, I can only observe that delusions of accuracy and precision are the hallmark of this fantastically self-satisfied ‘field’ of ‘climate science’.
WRT your question, I believe there are numerous knowledgeable and intelligent people out there but they take frequent vacations. Very typically, they travel to places that are warmer than where they live. I really don’t know if that fact has any significance.
I am always somewhat suspect when people point to evidence in ice cores. Even more so when they talk about methane in this context. Methane is much more reactive than CO2 and although ice cores are cold, they are not absolute zero. I am sure they attempt to correct for this, but what uncertainties does this introduce? How confident are they that they understand these uncertainties and have accounted for them properly?
Why cant we put stake in the heart of the Global Warming Fanatics?? They dont quit and they continue repeating the same dull chant as there there were no other questions to be answered and no possiblity of ever being wrong.
They are like the cult of Landrew; dangerous relentless robotic humanoids.
Don Mattox: GAO is not qualified to give that kind of recommendation since they are, essentially, a bunch of accountants. Their brief is to review Government expenditures to make sure they are 1) being spent as the appropriations direct and 2) in a somewhat efficient manner. Having said that, the GAO is also an intensely political organization that has no problem whatsoever in showing what their sponsoring Senator or Representative wants them to show.
OT, Political
The people have been in the back seat since 1913. That was the year we gave the keys to someone we trusted. Our benevolent government. They gave us back in that same year the Federal Reserve and the IRS.
We have been in for a wild ride ever since. Instead of us doing the driving, we gave control to the Governors of our country, for them to take us where they wanted to go.
All the Tea Parties are saying is, We the people want the keys back.
How about trying the Constitution for a change. We can start with, no undeclared wars. Period.
When our republic started back in 1776, all the people agreed to live by the bill of rights and the constitution. They conquered the land mass from England that stretched from Main to Georgia. That’s the whole Jersey Shore and then some. And the whole of the Atlantic Ocean was their Protection from the people they just stole that whole of a land mass from that stretched from Main to South Georgia. The lack of technology gave Great Briton a snow balls chance in hell of taking it back from us.
Now the question is; How are they going to govern themselves? That’s a lot of nice real estate, and the people that did the conquering were only about 8% of the entire population at the time. But that 8% gave to the other 92% something they all agreed with. Most farmers in the field at the time had very little idea a major war was going on. They had no technology to get information to them except by word of mouth. There was very little opposition publicly to what that 8% gave them afterwords. A woman asked Benjamin Franklin: What have you given us, a democracy or a republic? Ben replied, A republic, if you can keep it. Ben also said, a democracy is two wolves and a sheep deciding what is for dinner? A republic is two wolves and a heavily armed sheep deciding what is for dinner.
The second Renaissance began at the time of our founding fathers. You know, the guys who were generals and statesmen at the time, about 8% of all the people that lived between Main and Georgia, those years between 1775 and 1776. Those guys reached deep down and came up with a plan to govern our country called the bill of rights and the constitution some 11 years later. You could call it The New Utopia at the time, and wouldn’t be exaggerating.
All this my friends with the riots going on in Europe and the Tea Parties rising, I say we are in our 3rd Renaissance. And you know this because you are moving into the drivers seat, again.
The Tea parties are taking the keys out of the hands of both the DINO’s and RINOS’s They are kind of the remnant of we the people. The way it was originally supposed to be, where the people were to be in charge and in the drivers seat. It’s making a lot of people mad, but so be it.
Until someone comes up with a better plan, we want to stick with the previous plan that worked. That’s what is going on now.
Accelerated methane release from various sources as a positive feedback to general global warming remains a subject of intense research and huge unknowns. Furthermore, the fluctuation of atmospheric methane concentrations (while generally going up over the past many decades) is even more variable and the sources and causes less well understood than the the fluctuations of CO2, which, we all know, has been increasing far more steadily. The issue is far from settled on which way atmospheric concentrations will be headed in the short and longer but because of the potency of methane as a greenhouse gas, any growth of atmospheric concentration over the long term represent a serious enough threat to climate stability that in needs close monitoring.
I note they talk in parts per billion as opposed to CO2 which is parts per million.
The oceans are full of methane because the 139,000 active submarine volcanoes pump out CH4 and CO2.
As Dr Spencer has advised us that the oceans are cooling CH4 is also reducing as it should.
But surely the theory is disproven because there weren’t positive feedback and runaway warming in previous warm periods, there were always subsequent cool periods.
I’m having a hard time wrapping my head around the idea that methane levels “exceeded 1,730 parts per billion (ppb), almost twice the maximum amount measured over the past 650,000 years in ice cores (AR4WG1: 3).” and similar claims re CO2… I cannot help but suspect that its far more likely that there’s a flaw in using ice cores this way, that the ice isn’t entraining “old” methane and/or CO2 accurately wrt historical levels….or how we handle them, or something along those lines. I mean, certainly the values are possible – but how probable is it, really, that methane levels would be so grossly higher than ever before over the last 650,000 years?
BillD;
I don’t have the numbers in hand, but I have read that the tundra is the largest store of dead organic matter that would be converted to CO2 if the ground melts. Another few degrees of warming in the arctic will have a big effect.>>
Let’s think this through. Let’s start by accepting the notion that the tundra is the largest store of dead organic matter. Where do we go from there? Well, let me ask the obvious, how did all this dead organic matter get there? Did someone ship it there? No, doesn’t seem likely, pretty expensive to ship your garbage that far in recent times, and before that shipping and trucking hadn’t been invented yet…OK, it musta growed there and then it died. Hmmm. Too cold now for anything much to grow there, hardly any plants at all. No plants, no animals. Hmmmm. I got it! The climate must have been WARMER there at some point in the past than it is now. Really nice and warm with lotsa plants and animals and such. Now wait a cottin pickin minute. Didn’t Mann and Jones and Briffa tell us that the current warming is unprecedented? Never been warmer than it is now? Clearly it was warmer, a LOT warmer, and then it cooled off. Is that the decline they were hiding? No, never mind, different decline. Anyway it was warmer then, what caused it? No real large human population back then, musta been natural causes. Would be nice to know in case the happen again. Hey! They might be happening right now for all we know! In any event, if it was that warm in areas that are now tundra, the rest of the planet must have been scorching. Boiling! Tipping! Islands capsizing. Trees bursting into flame. Yes! Spontaneous arboritic combustion! Clouds of smoke and haze, dead rotting fish washing up on shore, mountains of dead animals decaying into disgusting ponds of rotten flesh. Methane and CO2 being released into the air in monstrous quantities… wait, which way does it go, co2 cause warming or warming causes co2… never mind not important. Point is that this would have been cataclysmic, a world wide event scorched into the geological and paleoclimactic records. What? No such record? Nothing?
OK, never mind.