Hi I think there may be a few errors in the post below. I broadly agree with the 'call to arms' but would like to comment on the following glitches in the arguments as set out:
Without time periods on fluxes, they aren't meaningful Fluxes don't mean increased concentrations - look at the trend line for the conc. of CH4 in the atmos. A lot of the methane is getting oxidised in the water column or atmos. The action of methane isn't necessarily stronger over the poles, as much of the polar amplification may come from oceanic heat transport into the polar regions. Mixing times and residency times don't tally - the methane would be largely oxidised before it made it to the arctic. Whilst I'm on the phone, I'd also like to comment on JN's recent post. He's normally an uber-hawk on methane, but I'm beginning to thin that even he doesn't go far enough. The fact that warming pulses can slowly permeate through the permafrost and into clathrates regardless of the overlying temperature is beginning to terrify me. It therefore may already be too late for geoengineering, and we urgently need to model this heat transfer and the potential geoengineering responses, in order to find out exactly what we can do to arrest the clathrate breakdown. A On 17 April 2011 00:52, scas <[email protected]> wrote: > Even as a layman I can't understand why scientists everywhere aren’t > hollering their heads off – perhaps it is because after studying and > observing global warming proceed at a snails pace for decades, they > have been lulled into a calm? > > Methane levels in 2011 are 1.8 ppm, an atmospheric total of ~3.5 Gt C. > As of 2009 methane fluxes in the ESAS are adding 3.5 Gt C to the > atmosphere [1]. If i’m not mistaken, that has just doubled the > atmospheric methane burden in a year, and tripled as of 2011. I don’t > know how much of that gets oxidized. Releases of up to 50 Gt of > hydrate is possible at any time [2]. Mixing time for methane is about > a year, but major releases in the Arctic would take 15-40 years to > spread to the South Pole [3]. Is the long mix time a good or bad > thing? Would 3.5 Gt C be considered a major release? Methane focusing > heating in the Arctic just speeds the whole melting process up. Once > the heat pulse starts penetrating hydrate sediments, top-down cooling > won't stop the process either [3]. > > James Hansen predicts 2012 will be the hottest year on record. I don’t > see how methane release can go anywhere but up. With the number of > recent earthquakes, could even greater releases be occurring > unnoticed? I think the precautionary principle means we should be > treating this as an emergency and have geoengineering capacity on > standby. > > [1] > http://symposium.serdp-estcp.org/content/download/8914/107496/version/1/file/1A_Shakhova_Final.pdf > > [2] http://www.cosis.net/abstracts/EGU2008/01526/EGU2008-A-01526.pdf > > [3] > http://groups.google.com/group/geoengineering/attach/b9fcdd6ead8da6f3/Methane+Blowout+Events.pdf?part=4 > > [4] http://climateprogress.org/2011/04/11/extreme-warming-temperature-map/ > > > On Apr 16, 2:51 pm, John Nissen <[email protected]> wrote: > > Hi Alvia, > > > > I said: "we are now in a desperate situation calling for emergency > action". > > > > You dispute this. Thanks for your honest opinion about the gravity, or > > otherwise, of the situation as you see it. But isn't your opinion > > rather wishful thinking? > > > <snip> > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/geoengineering?hl=en. > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
