Hi, Josh - I'll take up your comments later, but first, I mentioned the simple use of ground-based SO2 emissions as a practical way to fight hydrate releases for now, which should be more or less socially acceptable and could possibly therefore be undertaken very soon as suggested by John Nissen and his Emergency Group. I suggested that adding ~5% global S emissions might not be unacceptable to environmental concerns, as long as no one locale had too high a loading. In fact, that local limit of loading would mean that the total would end up being about 15x less, and so just a fraction of 1 percent.
Let’s imagine that we take, going from the paper Andrew just posted on rice and sulfur, 100kg S/ha/yr rate of S deposition as our upper limit (essentially, 100% of S sink is dry/wet deposition, and so, for the moment, we’ll just take our emissions from that too, and forget about transport issues for the moment), although it is predicted to be some 150 kg S/ha by 2030 in the worst parts of South Asia, I think the paper said (I'm also leaving out that health limits are really expressed in 24 hr limits too, I believe). So, Semilitov mentions finding these densest plumes over an area of ~10,000 sq mi. So, 10,000 sq mi. at this highest acceptable loading level would give us a total of .259 Tg S/yr. I was apparently underestimating the total global S emissions a little, which are not 60Tg, but more like 70-80Tg S/yr according to something I just found online (am traveling now & so I don’t have AR4, etc.). Thus, the total area Semilitov is currently looking at, with SO2 emissions spread throughout it at about the highest levels accepted today would only add about .32% to global sulfur emissions. That would mean that it could be tripled to 30,000 sq mi and still just add 1% to global S emissions. Now, who can calculate what the local -RF of this S loading would give in W/m2? I've seen things posted here talking about locally determined arctic RFs in various contexts, I think from John, but not sure how it's derived. Also, what about means of delivery? I mentioned ships before, but then of course it couldn’t be done in spring when there is still ice throughout the region. Maybe something else could be used onshore in spring, sitting on the ice, and then ships could take over as the ice clears in summer......we would want it spread through all the lightest part of the year, to lessen negative impacts on wildlife, particularly around the Lena delta wetlands...... cheers, Nathan On Dec 20, 11:41 am, Josh Horton <joshuahorton...@gmail.com> wrote: > Hi Nathan, > > What concerns me is that the argument you present is based on > conjecture. Your conjecture may be correct, I have no idea, and > informed speculation is entirely appropriate for this type of forum, > but some are now asking policy-makers to make deployment decisions in > the absence of hard, time-series data demonstrating statistically > significant upward trends in Arctic methane releases. At least I > haven't seen such data, if it exists out there please pass along (and > I mean that most sincerely!). It may be that this sort of information > cannot be produced, or would be meaningless in practice, but it will > take something more convincing than what I've seen to persuade real > decision-makers to implement even regional geoengineering schemes. > And that is what some are now being asked to do. John's Arctic > Methane Emergency Group is publicly advocating deployment of some > combination of SAI, marine cloud brightening, and cloud removal as > early as spring of 2013, essentially a year from now. Rightly or > wrongly, I can't imagine someone in a position of authority signing > off on this based solely on the information I've seen to date. > > Before we propose deployment, or even large-scale field tests, we need > to meet a higher standard of evidence. I'm very concerned about ESAS > methane plumes, and I realize that the sort of regional tropospheric > aerosol schemes discussed by McCracken would hardly produce a > "frankenclimate," but I would hate to see the geoengineering community > discredited by a premature call for action that would almost certainly > be rebuffed, especially if it turns out there truly is an emergency > underway. In this case, at this moment, with the information > available, I think discretion is the better part of valour. > > Josh > > On Dec 19, 5:57 pm, Nathan Currier <natcurr...@gmail.com> wrote: > > > > > Hi, Josh – > > > I think one is seeing what you’d expect to be able to see: rather > > large perturbations from background levels right around large plumes, > > by as much as ~100ppb, I believe, and then progressively smaller > > deviations from background when considering larger regions, with the > > whole arctic sea quite dependably read by NCAR’s HIPPO as now having a > > (small) unexpected elevation from annually averaged background level > > (already a couple of years old now, I believe). Although it's a well- > > mixed & "LL" GHG, it's never going to be a simple story getting good > > readings of levels everywhere, and getting changed readings fro > > identical locations as you suggest, while of interest, wouldn't > > necessarily tell you what you want, either, since different taliks > > could be emitting at different rates sporadically, I believe, meaning > > the point emergences of densest emissions could be a shifting target. > > > In general, I think that depending too much upon top-down views of > > this situation could, potentially, lead to dangerously false > > conclusions, and that feeling complacency because of the smallness of > > the deviation over larger areas is possibly unwise. Let me jump to > > something seemingly unrelated to try to demonstrate what I have in > > mind: you know Lovelock’s metaphor of the earth being something like a > > camel (i.e., seeing the pleistocene swings as 'bi-modality'), or his > > simple model in which sensitivity can act 'more like a variable than a > > constant'? Imagine for a moment that methane acts as the primary near- > > term gear-shifter of climate at multiple scales/levels, not just as a > > follower of CO2, nor as the occasional “gun” that randomly goes off > > and blasts away the current climate system. So, as the 'gear-shifter', > > at certain thresholds of heating, wetlands start drying at certain > > latitudes, with the drying outpacing increased rainfall elsewhere, > > thus lowering emissions on balance, while at the same time submarine > > hydrates would begin to destabilize, and some permafrost and > > thermokarst emissions would start to pick up, etc. Together these > > changes of opposite sign, balancing themselves out, would create a > > false temporary stasis, although an important shifting of regime is > > going on. > > > It’s fine to say that most emissions are still coming now from the > > subtropics (i.e., Nisbet's quote), but might there be an invisible > > shifting of different methane emission sources WITHIN the arctic > > system going on that we haven’t pieced out, making something look like > > stasis or a lull, or finally now just a minor perturbation upwards, > > that is actually the system’s quiet preparation for a giant shift? > > Think of all the mystery about methane emissions in the 1990s going > > ‘flat’: probably wetlands go down, generally, but are gradually > > replaced by other methane emissions from much larger stores. This kind > > of thing would make total system behavior look something like what > > Lovelock is talking about. > > > Perhaps none of that is actually what’s going on, but it gives a > > scenario, anyhow, in which a top-down view of the total global methane > > budget, or even of the total arctic methane budget, wouldn’t alone > > necessarily be a useful indicator at all of the seriousness of what is > > going on. It certainly is indisputable that hydrate release could > > become devastating, and the leading experts keep finding larger and > > larger plumes as they keep looking - simply put, if those are caused > > by the contemporary local conditions, then that's a feedback loop, and > > then their increase constitutes grounds for considering it the > > beginnings of a potential runaway situation. > > > The kind of thing I was proposing could hardly create some > > "frankenclimate," and is no different than what is allowed to go on > > all over the planet all the time. Since it is relatively harmless, and > > the fear is of something catastrophic, it seems like an obvious sense > > of prudence to act - and sooner rather than later. > > > Nathan > > > On Dec 18, 6:30 pm, Josh Horton <joshuahorton...@gmail.com> wrote: > > > > Nathan, John, et al., > > > > One aspect of the methane issue bothers me in particular: is there > > > evidence indicating a significant increase in the rate of methane > > > release in the ESAS over the past decade? Anecdotal evidence from the > > > most recent Russian expedition suggests an increased rate of release, > > > but hard data will not be available until next spring. Such data may > > > have been included in the recent Shakhova et al. AGU poster, but so > > > far I have been unable to obtain it. > > > > Were comparable measurements taken at identical locations in 2003-2008 > > > (basis for the initial findings) and in 2011 (basis for recent > > > Semiletov comments)? Was there a significant increase in the volume > > > of methane released at these locations over these periods? If so, is > > > such an increase inconsistent with the Dmitrenko thaw hypothesis > > > (noted by Andy Revkin)? Until we have answers to these questions, I > > > hesitate to jump to any conclusions. Maybe you have information I > > > have overlooked? > > > > Josh Horton > > > joshuahorton...@gmail.comhttp://geoengineeringpolitics.blogspot.com/ > > > > On Dec 18, 4:06 pm, Nathan Currier <natcurr...@gmail.com> wrote: > > > > > Hi, John & list – > > > > > Until now, my view has generally been that we should try like crazy to > > > > get > > > > some rapid SLCF declines, by promoting a separate near-term-focused > > > > emissions strategy, > > > > in an attempt to blunt accelerating arctic methane emissions, while at > > > > the same time > > > > researching geoengineering techniques, which would probably still be > > > > needed at some point later > > > > down the road. The hope was that the need could be pushed a few > > > > decades off, if a strong > > > > CH4/BC program – something considerably stronger than the GMF or the > > > > GMI – > > > > were started up soon enough. > > > > > But I am now coming more and more to your position, John – I now think > > > > that a local-scale > > > > intervention should probably be pursued as quickly as possible. I > > > > still believe that everyone > > > > interested in the goals of this list should also be thinking about how > > > > SLCF reduction can > > > > somehow be expedited, since it is ultimately the cheapest, safest -RF > > > > there is, in that every > > > > dollar spent on it goes at the same time both to solving our long-term > > > > climate problem > > > > (and is thus in any case essential), and also mitigates the immediate > > > > “feedback crisis” > > > > we are increasingly in, to use Wasdell’s apt term. > > > > > But I would have to agree that it is now becoming more and more > > > > rational to want to > > > > act right away, albeit on a local scale. Moreover, those promoting the > > > > views of > > > > ‘nay-sayer’ scientists on ESAS dangers, like Andy Revkin at the NYT, > > > > are starting > > > > to look less and less rational, almost desperate, and reading his post > > > > of a few days ago, > > > > linked below, in fact only convinced me that his attitude is really no > > > > longer tenable. > > > > >http://dotearth.blogs.nytimes.com/2011/12/14/methane-time-bomb-in-arc... > > > > > A year and a half earlier, Revkin had a post of much the same gist: > > > > >http://dotearth.blogs.nytimes.com/2010/03/05/the-heat-over-bubbling-a... > > > > > I’m not sure how Ed Dlugokensky and Euan Nisbet really feel about > > > > being used to promote complacency > > > > about this now, as Euan Nisbet has long been concerned about it > > > > (although very wary of any geoengineering), > > > > and I gather from powerpoints of Dlugokensky I have seen that he > > > > really is, too. > > > > > To summarize, the key justifications for this “don’t worry about it” > > > > attitude on ESAS methane emissions have > > > > been and still are: > > > > > 1. the methane plumes might not be new, merely newly observed. > > > > > 2. these emissions still count for but a small fraction of the global > > > > methane budget. > > > > > 3. the driver of these emissions is actually not contemporary warming, > > > > but adjustment of the underlying > > > > hydrate stability zone > > ... > > read more » -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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