Methane is unstable and breaks down quickly in the atmosphere, and even if it doubled would have essentially no impact on the greenhouse effect. In the tropics, the effect would be an increase in downwelling longwave radiation of about 0.04%.
If everyone in Kansas City was an atmospheric molecule, only one of them would be methane. Anyone working on climate models and doesn’t know this, is driving under the influence of AGW stupidity.
Most of it is natural anyway. Swamp gas. Always been there.
And the methane gobblers get to work pronto!
http://www.pbs.org/newshour/rundown/2011/01/methane-munching-bacteria-consumed-at-top-speed.html
“If everyone in Kansas City was an atmospheric molecule, only one of them would be methane.”
The lone vegetarian in a city of great BBQ.
We are often told that methane is 20 times as powerful a Green House as CO2. I always wondered why and looked it up some time ago. What I came up with is the fact that there’s so little of it. It doesn’t take much to double the amount of methane in the air, so they tell me, a little bit of it has a bigger effect than the same amount of CO2. I can’t say that I believed this explanation since its absorption spectrum barely impinges on the atmospheric window, but that’s what I found. I’d put up the link where I found this answer if I could find it again.
Methane has almost no effect if water vapor is present, because of low concentration and because the bands overlap. The claim is complete BS on planet Earth.
They use the fact that methane has not grown as predicted when they try to excuse Hansen’s 1988 projections.
It wouldn’t have made any difference if it did grow as he projected to 5 ppm. Given the overlap with H2O absorption bands and very low concentration.
There’s no methane in the southern hemisphere:
https://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/AIRS_Methane.png/220px-AIRS_Methane.png
but they tell us anthropogenic CH4 is part of the ozone hole issue
Even if you don’t burn it, methane (CH4) in the atmosphere oxidizes fairly rapidly, changing into (negligible amounts of) harmless CO2 and water:
CH4 + 2 O2 -> CO2 + 2 H2O
Various sources give the half-life of CH4 in the atmosphere as 6-8 years, which would make the average lifetime 1.4427 times that (because oxidation is an exponential process, rather than linear), yielding an average lifetime of a molecule of CH4 in the atmosphere of 8.7 to 11.5 years. Page 11 of this source gives the directly-calculated atmospheric lifetime of CH4 as ~8 years, but identifies a feedback mechanism that (they say) effectively increases the atmospheric lifetime of additional CH4 to ~12 years.
Call it 8-12 years. That’s pretty short. It means the only reason CH4 levels are as high as they are (about 1.8 ppm) is that CH4 emissions are already high. There would have to be a very large, sustained increase in CH4 emissions to cause much increase in long-term average atmospheric CH4 levels.
The fretted about source for such an increase is supposedly the thawing of huge amounts of frozen methane hydrates. That seems very unlikely, considering that ~900 years ago, during the Medieval Warm Period, parts of Greenland were warm enough to grow barley (and it’s too cold to grow barley in Greenland now), yet there’s no evidence of any giant “pulse” of warming 900 years ago.
The threat should not be completely ignored. .8c warming globally and 1.5c for the Arctic raises concern for the permafrost releasing its’ huge sink of methane. Also, minimizing the threat by focusing on concentrations is misleading. Methane and CO2 don’t need dense concentrations to have an effect on intensifying water vapor. Think of the outfield in baseball with 3 players. Add one or two players and you catch a lot more fly balls. Add 50 players and you don’t really catch any more than with 5.
Dumbasses have been predicting that for more than 40 years now. No more likely now than it was back then. If you’re really worried about it, though, you’re perfectly welcome to give up electricity & gas & go live in a mud hut.
Be the change you wish to see.
I’ve actually lived in a mud hut for a number of years, without electricity and hardly any fossil fuel. You end up instead burning a lot of wood, collected from the forests.
The problem with scare stories is that one can invent an endless supply of them.
It is not a scare story. It simply helps make the case that we should not do nothing about dumping our carbon emissions into the air. The “what me worry” crowd is scary to me.
“Carbon emissions?”
It’s called carbon dioxide, and your lungs are full of it. Plants call it “food”. Only alarmists call it a problem.
Body thetans are pretty scary, matatatayayataya. You’d better go order an e-meter from Tom Cruise RIGHT NOW!
Correct me if I’m wrong, matayaya, but isn’t your other name Jai Mitchell? Concerning “carbon emissions”, granted we should minimize particulates as well as incompletely burnt hydrocarbons, for these are indeed pollutants. But carbon dioxide is another matter altogether, since it is essential to all life. I’ve been long a plantsman, so I can attest to that.
Is there any full report on this ? A complete blog post or scientific report ? a resume ? showing all these claims that methane has almost no effect whatsoever…
I’m asking because the lobby against the livestock business in Brazil has grown very rapidaly in the last years based on the problems methane could cause. Furthermore, every newspaper corroborate that and there aren’t many portuguese materials to argue against it.
I would be much obliged if you could hepl us here.
Thanks,
There are a number of very technical papers demonstrating overlapping bandwidths, and then simple common sense posts like this.
http://stevengoddard.wordpress.com/2011/07/16/methane-is-bs/
“What if scenarios” are the essence of science. If we were talking paleontology instead of climate science, needed policy making would not be an issue. Since we are talking “what if” permafrost thaws, then someone sees and economic or political issues and claims scare tactics. It is still simple, yet important science to hypothesise.
Formulating hypotheses may be essential to proper scientific method, but it is not sufficient. It is necessary to also test and verify them.