Over at Juan Cole’s Informed Comment site, he’s found a report on the “Mystery of the Excess Methane” (cue ominous music).
A big mystery is where all the methane in our atmosphere has come from. Since 1820, the average amount of methane has about doubled. Nearly 200 teragrams of methane seems to be going into the atmosphere every year. How much of that is produced by nature? Or are human activities releasing it in unusual amounts? Whodunnit?
This is important to know because methane is worse in it’s immediate heat trapping effects than CO2 by a factor of 80 — causing an estimated 20% of warming currently. It’s shorter lived, but as long as it’s increasing, it amplifies the effects of CO2.
To cut to the chase it turns out the villains ARE the usual suspects. In this case, the oil and gas industry and the weapon is drilling and fracking, which is causing huge releases of methane into the atmosphere. I saw an article about this a few weeks ago — detection of huge methane plumes over oil and gas fields. A report in Nature (linked to in Cole’s article) and cited by the Guardian (also linked to by Cole) comparing the amount of methane in 300 year old ice cores shows volcanic and other geologic activity accounts for a little over 5 teragrams of methane/year. Oil and gas drilling and fracking is responsible for almost all the additional methane release.