“The amount of methane in Earth’s atmosphere shot up in 2007, bringing to an end a period of about a decade in which atmospheric levels of the potent greenhouse gas were essentially stable, according to a team led by Massachusetts Institute of Technology (MIT) researchers.
Methane levels in the atmosphere have more than tripled since pre-industrial times, accounting for around one-fifth of the human contribution to greenhouse gas-driven global warming. Until recently, the leveling off of methane levels had suggested that the rate of its emission from the Earth’s surface was approximately balanced by the rate of its destruction in the atmosphere.
However, since early 2007 the balance has been upset, according to a paper on the new findings being published this week to be published in Geophysical Review Research Letters. The paper’s lead authors, postdoctoral researcher Matthew Rigby and Ronald Prinn, the TEPCO Professor of Atmospheric Chemistry in MIT’s Department of Earth, Atmospheric and Planetary Science, say this imbalance has resulted in several million metric tons of additional methane in the atmosphere. Methane is produced by wetlands, rice paddies, cattle, and the gas and coal industries, and is destroyed by reaction with the hydroxyl free radical (OH), often referred to as the atmosphere’s “cleanser.”
One surprising feature of this recent growth is that it occurred almost simultaneously at all measurement locations across the globe. However, the majority of methane emissions are in the Northern Hemisphere, and it takes more than one year for gases to be mixed from the Northern Hemisphere to the Southern Hemisphere. Hence, theoretical analysis of the measurements shows that if an increase in emissions is solely responsible, these emissions must have risen by a similar amount in both hemispheres at the same time.
A rise in Northern Hemispheric emissions may be due to the very warm conditions that were observed over Siberia throughout 2007, potentially leading to increased bacterial emissions from wetland areas. However, a potential cause for an increase in Southern Hemispheric emissions is less clear.
An alternative explanation for the rise may lie, at least in part, with a drop in the concentrations of the methane-destroying OH. Theoretical studies show that if this has happened, the required global methane emissions rise would have been smaller, and more strongly biased to the Northern Hemisphere. At present, however, it is uncertain whether such a drop in hydroxyl free radical concentrations did occur because of the inherent uncertainty in the current method for estimating global OH levels.”
Read more here from David Chandler at the Massachusetts Institute of Technology.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Warning, warning, spiv alert, spiv alert!
Last time I checked, a single one year rise in the level of a gas, especially after a decade of stability, does not constitute an “imbalance”.
Note how the article is really short on specifics. All we are told is that there are “several million metric tonnes of additional methane”. So exactly how many is “several”? Do they actually know? And what volume of methane is this “several million” added to?
Not a single verifiable fact in the whole article. Plus ca change ..
It would be great to get a copy of the actual journal article. Does anyone have a pdf they could send me? Luke perhaps?
Ian, I am not overplaying the significance of a “one year rise”, it’s interesting but hardly alarming, but your statements above aren’t quite accurate.
The article states:
“Methane levels in the atmosphere have more than tripled since pre-industrial times” – so it seems to part of a longer trend, so it’s not really a single one year rise as you suggest. But part of a longer rise that has been observed for a long time.
“However, since early 2007…” That would also make it closer to 2 years…
“Not a single verifiable fact in the whole article.” It’s a news article, a summary of what you will read in the upcoming article in Geophysical Research Letters
“Methane is produced by wetlands, rice paddies, cattle, and the gas and coal industries, and is destroyed by reaction with the hydroxyl free radical (OH), often referred to as the atmosphere’s “cleanser”
That looks like a verifiable fact.
“One surprising feature of this recent growth is that it occurred almost simultaneously at all measurement locations across the globe. ”
That does too.
The point of the article, to my reading, is that they think the levveling off was due to an equilibrium between the creation and destruction of methane (which happens quite rapidly), so the only way for methane to rise is by unsettling that equilibrium. I am not sure how else you could describe it.
CO2 going up. CH4 going up….. Temperature still going down….
Not much going right for this AGW Hypothesis.
A record rate in the rise of CH4 in a year with record arctic melt with a record cooling rate over the same year. Sounds like something is not working quite like it should.
“Sounds like something is not working quite like it should.”
do we really have any idea of what it should be doing?
do we really have any idea of what it should be doing?
Probably not but some folks seem to be certain that melting ice should cause less albedo and more warming because of it. 2007 can’t be considered evidence that it does.
Jennifer
Any luck with that link I gave you?
If you look at the Geophysical Research Letters cover on that page quoted as the latest issue, you will see that it was published at the end of August.
So, I believe that their paper will be published in a FORTHCOMING Issue and their press release stating that it had been already been published in Geophysical Research Letters was a little premature
Full Journal reference:
M. Rigby, R. Prinn, P. Fraser, P. Simmonds, R. Langenfelds, J. Huang1, D. Cunnold, P. Steele, P. Krummel, R.Weiss, S. O’Doherty, P. Salameh, H. Wang, C. Harth, J. Mühle, L. Porter. Renewed growth of atmospheric methane. Geophysical Review Letters, 28 pages 2008
Yep Geoff,
According to Paul Biggs:
There is no Geophysical ‘Review’ Letters – it is Geophysical ‘Research’ Letters and the paper is in press:
Rigby, M., R. Prinn, P. Fraser, P. Simmonds, R. Langenfelds, J. Huang, D. Cunnold, P. Steele, P. Krummel, R. Weiss, S. O’Doherty, P. Salameh, H. Wang, C. Harth, J. Mühle, and L. Porter (2008),
Renewed growth of atmospheric methane,
Geophys. Res. Lett., doi:10.1029/2008GL036037, in press.
There’s a published study (no, I don’t know where, I read it before I started to take notes) on the effects of SO2 on Arctic methane production. It suppresses it. We have cut back hugely on SO2 emissions and it is obvious that atmospheric methane is going to increase as the SO2 brakes come off all over the world. Presumably SO2 is as well mixed as CO2, so we would expect it to have an effect wherever there are wet bogs and bacteria to rot them down, ie, everywhere.
Today, a methane uptick. I told you so in Feb 06 in answer 2A1 on my website and I’ve been wondering when it would turn up.
The only update I’d add to my solution to warming is a need to study the emissivity of oil-polluted surfaces — my guess is that smoothed seawater doesn’t cool as fast in winter and warms more in summer, which sounds very much like the processes at work in the Arctic. With that addendum I think we’ve got it sussed. Today methane, tomorrow the world!
Unless it all turns out to be more hype. If so, pretend you never read this.
JF
And while we wait, yet again, for some verifiable data from the climate zombies, it is timely to remind ourselves that the atmospheric concentration of CH4 is measured in PARTS PER BILLION while that of CO2 is measured in parts per million. So one should never, and honest report authors should take considerable steps to ensure their readers do not, assess Methane changes in the same numerical relevance as CO2.
We await a demonstration of their bona fides with interest.
A bit late, but here is the link to the full version of the Rigby paper on CH4:
http://www.mit.edu/~mrigby/publications/2008GL036037.pdf
A team of MIT scientists recorded a nearly simultaneous world-wide increase in methane levels -the first increase in ten years. What baffles the team is that this data contradicts theories stating humans are the primary source of increase in greenhouse gas. It takes about one full year for gases generated in the highly industrial northern hemisphere to cycle through and reach the southern hemisphere. Since all worldwide levels rose simultaneously throughout the same year, however, it is probable that this may be part of a natural cycle – and not the direct result of man’s contributions.
http://www.dailygalaxy.com/my_weblog/2009/03/scientists-at-m.html