http://www.bbc.com/news/science-environment-38285300 So atmospheric methane is up, why? No one is sure, I would put a bet it is from the fracking, that is methane that leaks from fracking. The simplest way to know would be to check the carbon C12/C13/C14 ratio of the methane as geological methane should have a different ratio from biological methane.
More human , more cows and pigs, temo. increase, release methane gas in Siberian tundra, as Ocean water gets warmer more gas is released from ocean's bottom deposits ete. ete.
Billy T was predicting this a long time ago - he pointed out a couple of years ago that the half life of methane in the air was rising sharply, which indicated the methane destruction pathways were saturating - and when they saturated, the increase in methane would jump to a much higher rate quickly. It doesn't have to be an increase in production, in other words - although that's likely to be contributing.
Billy T made a lot of predictions, I use to ask him every year after his predicted downfall of the USA when it was happening. But sure saturation seem possible, it depends how much of it is due to auto-oxidation in air.
It was being measured. The half-life of methane in the atmosphere was rising and the rise was accelerating, demonstrating (probably) approaching saturation- in the near future, upon saturation or near saturation of whatever pathways were involved, that was going to result in a sudden, rapid, and large boost in the methane concentration regardless of increase in methane production.
Indeed. I didn't disagree with most of his fundamentals (i.e. methane output, and concentrations, would rise) just his conclusions (therefore humanity will be extinct within a few generations.)
Methane as a green house gas is far worse than co2. And fracking leaks alot of methane gas . and the arctic warming , tundra etc . could expel alot of methane gas as well , if not already .
But goes away a lot faster. Hence the relative problems with CO2 (which sticks around for a long time, but has a lesser effect) and methane (which breaks down more rapidly.)
Yet ; http://www.onegreenplanet.org/animalsandnature/methane-vs-carbon-dioxide-a-greenhouse-gas-showdown/
A few minutes on Google answers your question. CO2 does not have a half-life per-say, the carbon cycle complicates things, but a rough estimate <500 years https://www.skepticalscience.com/co2-residence-time.htm Methane is inherently unstable in our oxidizing atmosphere and has a half-life of only 8.4 years. http://www.grida.no/publications/other/ipcc_tar/?src=/climate Poor poor Mr. Quick
That half-life is changing - getting longer. And the rate of that change is changing (last I, following one of Billy T's links, checked) - getting higher. That predicts a breakover event - a sudden, large, and continuing boost in the methane concentration - even without any increase in production.
Hmm. I don't think we're going to run out of OH radicals in the upper atmosphere, so I wouldn't worry about that too much.
Well, we are in statistical fact running lower than before on whatever it is that is supposed to degrade methane - and the shortage seems to be getting more significant. Not only that, but there is a positive feedback loop - higher concentrations of methane of themselves reduce the rate of degradation, by saturation. One should pick a point at which to begin worrying, maybe, in advance - just so it doesn't catch us on the blind side, so to speak.
You don't really need them. Just line up some half-life estimates from reputable sources at different times, and watch the trend. Here's an older one: http://phys.org/tags/methane/ The sidebar, apparently not updated recently gives us this: Moving to the latest Wiki entry, we get this: And so forth. btw: There's also this little cloud on the horizon, in Wiki:
I'm not assuming a mechanism. Most sources point to a decreasing local concentration of OH radicals, exacerbated by the escape of missed methane in the lower air and its transport to higher, drier, thinner air levels.