From UC Irvine:
UCI studies find different reasons for global methane riddle
One cites less dependency on oil, the other new farming practices
Irvine, Calif. – Two new UC Irvine papers reach markedly different conclusions about why methane, a highly potent greenhouse gas, unexpectedly leveled off near the end of the 20th century. They appear today in the journal Nature.
Both note that after decades of increases due to worldwide industry and agriculture, the tapering off of the hazardous hydrocarbon in the atmosphere – which began in the 1980s – was remarkable.
“It was an amazing mystery as to why this occurred,” said earth system science professor Eric Saltzman, a co-author of one paper, which suggests that reduced use of petroleum and increased capture and commercial use of natural gas were the driving factors.
A second UCI paper found that water efficiency and heavier commercial fertilizer use in the booming Asian farming sector provided less fertile ground for soil microbes that create methane, while at the same time increasing nitrous oxide, another greenhouse gas.
Associate researcher Murat Aydin, lead author on the first paper, drilled into South Pole and Greenland glaciers to extract trapped air as much as a century old. The samples were analyzed for ethane, a chemical that has some of the same sources as methane but is easier to track.
“Levels rose from early in the century until the 1980s, when the trend reverses, with a period of decline over 20 years,” Aydin wrote. “We find this variability is primarily driven by changes in emissions from fossil fuels.”
The authors posit that replacement of oil with lower-priced natural gas could be key.
The second team measured and analyzed the chemical composition of methane in the atmosphere from the late 1980s to 2005. They found no evidence of fewer methane atoms linked to fossil fuel. Instead, the sharpest trend by far was changes in the Northern Hemisphere linked to new farm practices, mainly the use of inorganic fertilizers instead of traditional manure and drainage of fields mid-season.
“Approximately half of the decrease in methane can be explained by reduced emissions from rice agriculture in Asia over the past three decades, associated with increases in fertilizer application and reductions in water use,” said lead author Fuu Ming Kai, who wrote his UCI doctoral thesis on the work and is now with the Singapore-MIT Alliance for Research & Technology.
Martin Heimann, director of Germany’s Max Planck Institute for Biogeochemistry, was asked by Nature editors to write a commentary on both papers.
“It is indeed very remarkably rare that two differing studies about the same subject come out from the same department – I can’t think of a similar case. But I think both analyses are scientifically sound and in themselves consistent,” said Heimann, lead author on the Nobel Prize-winning Intergovernmental Panel on Climate Change reports. “At this time I would not favor one over the other.”
Heimann has invited members of both teams to a September symposium at which, he said, “we will discuss the two studies from all angles.”
Identifying methane sources is urgent. Research has shown that the fast-acting greenhouse gas is the second-largest contributor to climate change. Scientists around the world were heartened by the stabilizing levels, but there are now signs the hydrocarbon may be on the upswing again.
“We will need to reconcile the differences,” said earth system science professor James Randerson, a co-author on the second paper. “The important thing is that we must figure out – as scientists and a society – ways to reduce methane emissions.”
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SSam says:
August 10, 2011 at 5:15 pm
Dave Wendt says:
August 10, 2011 at 3:19 pm
“…That is complete BS….” plus a link.
Now THAT was a useful link. Odd that H2O shows three times the downward forcing in winter than CO2… and that in summer it’s about TWENTY FOUR times that of CO2.
That experiment was done up in Canada. The authors were quite proud of the fact that they discovered an increase of 3.5 W/m2 in DLR due to CO2, but weren’t much interested in pointing out that it all occurred in the dead of winter which I suspect most Canadians would not find to alarming. The suppression effect of water on CO2 occurred at levels of total DLR of only 270W/m2 The Tropics, SubTropics, and even parts of the lower Temperate zone are above that level almost year round which suggests that if this effect could be verified it would show that over most of the Earth, most of the time, CO2 is an almost negligible contributor to the GHE. They did this experimental work in the late 90s. DLR has been monitored in dozens locations worldwide over the intervening years. AFAIK none of those sites has added the spectral analysis technique to their data collection. Since nearly my first reaction when I came across E&P’s work was that at last we have a means of empirically quantifying what each of the elements of the atmosphere contributes to the GHE, I have have always found that neglect extremely curious. It’s almost as if they really didn’t want to know, but that’s probably just my paranoia talking.
sophocles says: “Maybe, just maybe, the production of methane released into the atmosphere actually follows the real movement(s) in global temperatures?”
Kevin Kilty says: “No such luck. Methane has many sources, some of which release more methane with increasing temperature, so that the rate of production is a function of temperature..”
Since production can mean either the amount produced or the rate at which it is produced, “rate of production” in this context is like “rate of velocity,” a pleonasm.
The Google ad for gas and oil stocks says “NOW is the time to INVEST” which over the past three years of watching these surges in advertising for “GREEN” products tells me like all of the other times the “Established Smart money” is in a dumping onto the rubes of the public mode as the collapse of the price of the product drops out of sight in less than three weeks after the ads show up.
Somebody has to paying for these ads to roll over the useless paper, onto the unknowing public just before the crash at an inflated peak. I don’t play Russian roulette, or invest in stocks, nor believe the total BS about the contrived studies like these two papers with no back ground study, data or real field research behind them.
Abstract of the studies: “We don’t know nearly as much about this subject as we thought we did.”
O/T, Perseid meteor shower due tonight: click
Kevin Kilty says:
August 10, 2011 at 7:25 pm
“Creative! But you are a sick fellow just the same.”‘
Kevin – I did not author that bit of whimsy. It’s been around for at least a decade and usually surfaces in January, coinciding with Robert Burns’ birthday. It does appeal to the remaining bits of my long ago scottish ancestry though! MtK
The data is scientific and then come the conclusions. AGW scientists just make things up. They are allowed to do that. That is why they have wildly different speculations.
Looking at the data back to 1780, Methane has what appears to be a very predictable declining exponential trend. Even the IPCC in its first report had projected Methane to stabilize at around 2100 ppb. Today, it is pretty clear we will not reach 1850 ppb globally and the level is basically already at its stablization level.
http://img32.imageshack.us/img32/63/ch41780.png
Barrow Alaska, which has both the highest CO2 measurements and CH4 measurements in the world and the greatest seasonal difference and leads the trends in the rest of the world, is showing that the recent uptick in Methane is slowing down again. Mauna Loa as well.
http://www.esrl.noaa.gov/gmd/webdata/ccgg/iadv/graph/brw/brw_ch4_ts_obs_00011.png
Here is Methane back to the height of the last ice age. As Revkin noted today, there is no Holocene Optimum signal in Methane so the permafrost is not going to melt away and cause a Methane apocalypse.
http://img198.imageshack.us/img198/3613/ch420k.png
My bet is on the Oil and Gas industry because it fits the data best. Obviously a few other factors are involved but it is not Cows and it is not Rice Paddies.
When will real scientists write papers on green subjects? Or do they realize that it’s all foolishness?
D
Catalytic converters took over in the late 1970s–anybody but me think that matters?
I’m wondering what the effects of lakes drying up after the ice age is. I know it sounds odd, but I notice a lot of lakes (ponds) in MN have filled in the last 30 years. Obviously this would not create such a discontinuity discussed, but there must be some effect with the reduced rotting of vegetation.
View from the Solent wrote:
Close, but no cigar. Farmers have been feeding garlic to their cattle
The side effect – in addition to less methane – is better tasting steak sandwiches at Morton’s! And that’s a benefit for my waistline so I don’t need as much garlic butter, and that also reduces my methane production as well. It’s a win-win-win all around!
Mac the Knife says:
August 10, 2011 at 8:48 pm
Kevin Kilty says:
August 10, 2011 at 7:25 pm
“Creative! But you are a sick fellow just the same.”‘
Kevin – I did not author that bit of whimsy. It’s been around for at least a decade and usually surfaces in January, coinciding with Robert Burns’ birthday. It does appeal to the remaining bits of my long ago scottish ancestry though! MtK
=========================================================
Still, doesn’t mean you’re not a sick fellow! 🙂 ……. was a gas though.
“Scientists say that there has been a mysterious decline in the growth of methane in the atmosphere in the last decades of the 20th century”
It’s called Bean-O. Great stuff.
It is hardly going to explain global differences. But methane from deep coal mines was always routinely vented to atmosphere in the UK. Starting in the 1980s increasingly effective means of utilising the methane for power / heat generation were gradually introduced and by around 2000 they were generating quite a bit of power (and money!). But the power tends to be variable because the amount of methane emitted is heavily dependant on atmospheric pressure. So it isn’t always economic to install.
Methane is also given off from abandoned mines, unless the shafts are properly sealed, until the workings eventually flood. Here in the UK we have a LOT of abandoned coal mines.
The technology is readily available to oxidise mine gas methane where it isn’t practical to utilise it. A few years ago, this generated income through one of the Government’s greenie subsidies. (Renewables Obligation Certificates, if I remember correctly.)
But a few years ago it was decided that it was wrong to give any subsidies at all to the Evil coal industry (better give it to BigWind!) so, since then, any unutilised methane is just belched into the atmoshere.
Of course, in most of Europe coal mines are disappearing like the snows of yesteryear. Whilst over in Russia, China, India they are opening up everywhere. (Certainly in China, they are also introducing methane capture and utilisation for sound safety and commercial reasons).
All thi is probably nothing to do with fluctuating global methane levels (and there’s no evidence at all that it is a problem) but it’s funny that coal mine methane declines and rises in similar time frames?
Methane clathrates? Ocean temps stabilizing? Below 1500 m in temperate regions, there might not be enough temperature change. Methane clathrates under sediment are stable below 300m, such as in the Gulf of Mexico. Temperature changes here could release methane. In polar regions, rising temperature at depths below 250 m might destabilize methane clathrates.
The presence of methane could support the growth of sufficient methanotrophs perhaps enough to consume a significant fraction of the available methane. Or, perhaps temperatures to 500 m have stabilized in the last decade.
It takes many thousands of years for the methane to collect. The methane is produced by methanogens in sediments consuming what may be very old material. As temperature warms, methanogens will become more active as well. The methane released from the ocean oxidizes to CO2 in the atmosphere. This CO2 coming from ancient organic matter would mimic 14C depleted CO2 produced from fossil fuel.
http://www.springerlink.com/content/r4w867922g607w2j/
http://marine.usgs.gov/fact-sheets/gas-hydrates/title.html
AFAIK Methane is 60 times more effective as a Global Warming agent than CO2 … by weight.
So, it won’t take much of a decrease to completely swamp any CO2 effect.
Methane molecules not “atoms”
Dave Wendt says:
August 10, 2011 at 3:34 pm
I thought that all the permafrost areas of the planet were melting into bubbling caldrons of methane. What am I missing here?
Spot on David . I did some googling and back in 2007, in an article in Nature, they were saying the standard comments
http://terranature.org/methaneSiberia.htm
“A study published in the September 7th issue of Nature authored by Katey Walter of the University of Alaska, and Jeff Chanton of Florida State University reports that greenhouse gas is escaping into the atmosphere at a frightening rate”
and of course
“The vicious cycle of methane release and warming ….. taking climate change towards the tipping point …..”
and
Sergei Kirpotin of Tomsk State University describes permafrost melting as an “ecological landslide that is probably irreversible”. He says the entire western Siberian sub-Arctic region has begun to melt in the last three or four years.
An awful lot of methane must escape into the atmosphere from natural gas seeps. Natural oil seeps also result in gas coming out of solution from the oil. Microbes are pretty good at taking advantage of free food and they can metabolise the most unlikely substrates in the most unlikely redox conditions. Perhaps a slight temperature change has allowed more microbes to metabolise it. Perhaps methane just varies naturally across the globe, blown by changing wind patterns. Its a very low concetration gas if its measured in ppb and nature has very large sources and sinks for natural stuff like this.
I can’t help thinking this is a non-problem.
George Bush’s Methane to Markets program likely had a significant role in reducing methane emissions and Obama’s scaling back of the program likely had a role in the subsequent increase in methane emissions.
Unlike most politicians, GW did understand the science.
Although to suggest George Bush was the only person to ever do anything significant to reduce global warming would send the Left into meltdown.
EPA report on the Methane to Markets program which confusingly measures methane emissions in CO2 equivalents.
http://epa.gov/globalmethane/pdf/2010-accomplish-report/usg_fullreport_2010.pdf
Methane not a powerful radiative gas (avoinding the extreme misnomer of greenhouse gas). CO2 is more powerful. However due to the logaritmic relationships (more or less saturation) changes in relatively very low concentrations methane are more effective than changes in the more abundant CO2.
There was a question about the paleo concentrations of methane gas in ice cores. Essentially the Greenland isotope ratios (allegdly paleo temperatures) are somewhat different with time than the isotopes from Antarctica. CO2 follows the isotopes from Antarctica but CH4 is corrolating with the Greenland ice cores (no distinct lead or lag). However everybody seems happy with those differences, explaining it all with temperature. Not!
Is it possible to re-educate all these so called leading edge researchers in such a way that they are employable in the real world?
The settled science getting ever more settled by each published peer reviewed paper. After this one, CAGW is soooooooo settled that we cannot expect it to get “settleder” for many weeks to come. CH4 was expected to be the feedback-trigger to set off the most abrupt AGW changes by many doomsaday preachers. If it is not acting the way researchers have said it must, then the team has some serious “splainin’ ” to do. IMH, H, H, O.
I’m happy not to be a climate preacher these days. It is a very important field, but I would not want to have a history of claiming “settled science” and portraying horrific doomsday-scenarios these days as the questions get tougher and tougher. This will go down in history as a discipline that almost ruined the credibility of science. At least science as a way to dictate future political action. Sure they will claim that they never did anything but interpret data in an “objective fashion”, but the internet is full of documentation that clearly labels a lot of these people as snake oil salesmen with extreme fear as their product.
With the possible death of CO2 climate doom are we seeing the rise of the new ‘Methane’ climate doom which requires so much research and political changes and and course a Mathane exchange?