Sorry‹I am not enough of an expert to comment per the request, especially given complexities of the seasonal cycle, changing inversion strengths and extents, etc.
Mike MacCracken On 7/28/11 9:54 PM, "nathan currier" <[email protected]> wrote: > By the way, if 7% of total RF didn't sound that important in the last post, > please remember that that means an RF that is almost 16% as big as CO2's RF > since industrialization, and I was suggesting that we might conceivably have a > means to tackle it safely and quite cheaply, with existing technologies - so > that would be quite significant. > > cheers, > > Nathan > > On Thu, Jul 28, 2011 at 8:35 PM, nathan currier <[email protected]> wrote: >> Hi, Andrew - >> >> It would be great if someone like Mike MacCracken could comment on some of >> the chemistry in your posting - in that it seems to me confusing, and, I >> suspect, somewhat confused. Could you, Andrew, show the reactions that >> you're thinking of, so I could understand better? You say that - "If the >> coating acts on NOx and or the OH radical, it may even be counter >> productive!" and also say that "OH recycles NOx." Also you write: "NOx >> production uses free raw materials and is well mixed through the atmosphere." >> My understanding goes against pretty much all of this, if I am understanding >> you correctly. >> >> NOx certainly gets involved in reactions that lead to increased RF. But >> generally NOx is considered climate neutral, I believe, because if you take a >> NOx-centric view, you see it taking part in various reactions that have both >> positive and negative indirect forcings, and that roughly cancel each other >> out. >> >> If you look at, say, the NOx-methane interactions, where NOx laden air >> produces more O3 in CH4 oxidation, then that added forcing is generally >> counted for as part of CH4's indirect forcing, not counted for as a "indirect >> forcing" for NOx. That makes more sense, I suppose, in that the methane is >> fundamental to creating the greenhouse effect anyhow, is one of the most >> primary biomolecules on the planet, etc. >> >> NOx, I believe, always demands considerable energy to create (what did you >> mean by OH recycles it?), since it demands the splitting of the N2 triple >> bond, so the NOx in our air is almost all anthropogenic and comes from >> internal combustion engines and such. There's very little of it in unpolluted >> air, except from lightning and other high energy things. OH is the primary >> oxidant of the atmosphere, and, though it can fluctuate a good deal, the >> total budget is assumed to be surprisingly stable, given all the human >> assaults on the atmosphere. >> >> Thus, if you look at more recent RF pie charts (Shindell at GISS has done >> lots of work on indirect RFs), NOx is not there at all, but VOCs and CO >> obviously are, and are quite important - indeed, they have added twice the >> RF of N2O, which, unlike NOx, IS a fundamental part of non-anthropogenic >> chemistry and of the planet's GH effect. >> >> So, the way I see it, then, if you can catalyze more OH production directly >> from the sun's energy, either from singlet O or from splitting an O3 (not by >> creating new O3!), that's a very good thing. But, on the other hand, you want >> to get rid of NOx, not increase it. NOx will increase the CH4 indirect >> forcing, and while it will create some OH - and OH gets "reincarnated" in the >> process of the methane oxidation chain of reactions - that's your BAD OH, in >> that it's leading to the creation of more O3, I think. >> >> In terms of TiO2 being practical or not, obviously if white roofing is >> practical, then the photocatalytic surface is, too. They both use TiO2. And >> white roofing is the most "practical" of all geoengineering, in that no one >> is opposed to it. The surface would be much cheaper than the paint. Even >> solar energy might use TiO2 as well. Of course, if ALL of that happened, >> there'd be a big crunch on TiO2 and the need to search for new sources. >> >> The most confused part of your post seemed to me: "Tio2 works well on poorly >> mixed pollutants with a high contact area, none of which applies to methane." >> But that's the whole point: the NOx discussion is essentially a red herring >> in terms of climate impacts, but these >> "poorly mixed pollutants" - the VOCS and CO - are almost 7% of +RF since >> industrialization - and their RF is really all methane-related: It's an >> indirect forcing coming from the OH budget deficit they cause, in turn >> slowing the methane sink. >> >> But, you see, the TiO2 makes new OH from singlet O + H2O, or O3, and it acts >> on those "poorly mixed pollutants" like VOCs and CO effectively, as you agree >> - which are in copious quantities all around human surfaces. This should then >> cut down on that 7% of RF by reducing a major indirect forcing, and thus >> speeding up methane's oxidation. >> >> Cheers, >> >> Nathan >> >> >> >> >> >> >> On Thu, Jul 28, 2011 at 3:22 PM, Andrew Lockley <[email protected]> >> wrote: >>> >>> This proposed method of methane remediation is similar to the existing sink, >>> as although OH radical production isn't strictly catalytic, it does recycle >>> NOx. Whether the chemistry works or not is something I can't comment on. >>> >>> However, I don't think that TiO2 is likely to be practical. Although it is >>> leveraged (as it uses the suns energy), it is limited in the contact surface >>> area, potential area of application and the availability and possibly the >>> cost of raw materials. In contrast NOx production uses free raw materials >>> and is well mixed through the atmosphere. Tio2 works well on poorly mixed >>> pollutants with a high contact area, none of which applies to methane. >>> >>> I'm also not sure of the proposed TiO2 chemistry. If the coating acts on >>> NOx and or the OH radical, it may even be counter productive! >>> >>> I'd be prepared to be proved wrong on all of the above :-) >>> >>> A >>> >>> On 28 Jul 2011 18:50, "Nathan Currier" <[email protected]> wrote: >>>> > Hi Andrew, Sam, Oliver - >>>> > >>>> > I heartily agree, & think that this is potentially one of the >>>> > "sleepers" of the geoengineering world - >>>> > it is also unique in that it is neither CDR nor SRM & would probably >>>> > be quite safe & thus easily enacted. >>>> > >>>> > I would doubt that you're going after it the right way, though, Sam, >>>> > in that the kinds of things >>>> > you have been thinking about always demand passing air - which is way >>>> > too >>>> > energy-intensive. And Oliver, clearly one doesn't want to be >>>> > intentionally making >>>> > any new GHGs while trying to fix the GHG problem, unless it's making >>>> > something pretty damn >>>> > destructive of GHGs later on!..... >>>> > >>>> > Andrew, I'm not sure what you meant by "leveraging existing >>>> > processes", >>>> > but I had an idea in this general line several years ago, and actually >>>> > first learned of this >>>> > group when I saw Mike mentioning to Ken something about it...... >>>> > >>>> > In a sense, it is like using the band gap energy used in solar cells, >>>> > but the energy makes >>>> > hydroxyl instead.....of course, that's already a well developed idea, >>>> > and it all started >>>> > in Japan - it's sometimes called the "Fujishima effect" after Akira >>>> > Fujishima who started it. >>>> > It's been used in various forms of environmental remediation for quite >>>> > some time now. >>>> > >>>> > It's all about exploiting the unique photocatalytic properties of >>>> > TiO2. At this point there has now been lots >>>> > of research in Japan (and much of it not translated, I've been told), >>>> > and there are even commercial products >>>> > called "environmental nano-coatings" and so on. There's a leading TiO2 >>>> > expert at UVA (John Yates) who I approached about all this, >>>> > who told me once of visiting Fujishima, and being taken to a place in >>>> > Tokyo where a whole block of large city buildings >>>> > have been covered in a TiO2 coating, and studies have shown the NOx, >>>> > O3, & CO, VOCs and other reactive species >>>> > are all greatly reduced around there from the surrounding air - with >>>> > huge % changes, 30% and more. >>>> > >>>> > So, my simple idea had been this: if one thinks of the atmospheric OH >>>> > sink as a drain in which more reactive species selectively >>>> > go down more easily, raising OH anywhere and letting it act on VOCs >>>> > etc, should, globally considered, accelerate >>>> > the methane sink thus lowering the CH4 forcing (and that's behind the >>>> > "indirect GWP" concept of such species). Since >>>> > methane is a LLGHG, Sam, it's a waste to spend energy pushing air >>>> > around - methane is already everywhere. >>>> > >>>> > Therefore, an entirely passive approach could be to add a photo- >>>> > catalytic coating on top of white surfacing. It's a highly >>>> > synergistic concept, since the TiO2's unique hydrophobic/hydrophilic >>>> > qualities also make it an albedo booster (keeping white things >>>> > whiter), by being a self-cleanser of surfaces (TiO2 is used to keep >>>> > windows cleaner, for ex.) It would be MUCH cheaper than the white >>>> > paint used for the surfacing, by at least a few orders of magnitude. >>>> > My guess would be this approach could greatly boost the climate impact >>>> > of white surfacing projects, and I haven't seen studies exploring this >>>> > at all yet, although grad students at UVA told me it probably has >>>> > already been studied in Japan, and I never had good enough data to >>>> > even make my own rough calculations of what it might yield. >>>> > >>>> > Now, then, I mentioned that it's kind of like solar energy, in a >>>> > sense. Do you know of Graetzel, who started the Graetzel cell? >>>> > That's a solar cell that's TiO2 based (and could be the "Next Big >>>> > Thing" for the world, if it turns out well.....i.e., the solar slurry >>>> > idea). >>>> > I had once come across a very early paper of his, and think it could >>>> > lead to something in this area you are all looking at: >>>> > he was studying the capacity to degrade methane in ambient conditions, >>>> > & so was studying TiO2 with co-catalysts. He wrote a paper >>>> > on a molybdenum doped TiO2 that seemed to have a good action on >>>> > methane at ambient temperature. So this would be more like pulling the >>>> > methane right down the drain, rather than waiting for the lowered VOCs >>>> > etc to help the methane go down it. It would demand a LOT of work to >>>> > both explore various co-catalysts and see what's the best for directly >>>> > attacking methane, and then to determine which route would be better >>>> > to pursue - such a targeted catalyst, or a simpler "OH maker" that >>>> > targets nothing at all, but helps "open the drain." >>>> > >>>> > As far as that last goes, another thing: John Yates (the one at UVA), >>>> > while he right away told me that he "doesn't invent things," and thus >>>> > had no interest in getting involved directly in my pursuit, did >>>> > mention a curious thing to me, in a presentation he arranged for me by >>>> > some of his grad students. The unique properties of TiO2 come from >>>> > defects in the crystal lattice structure of the molecule. He's the >>>> > world's leading expert of this, a theoretical chemist who has spent >>>> > his life perfecting his own construction (a specially dedicated kind >>>> > of SEM, I think) to look deep inside the TiO2 molecule. One thing he >>>> > said to me stuck in my mind: it might not be hard, he said, to use >>>> > nano tech to expand the defect of the O atom, and thus get more OH >>>> > made through its band gap activation. So, this could make a more >>>> > productive molecule - either for making solar energy, or, I suppose, >>>> > for taking junk out of the air and lowering its RF. >>>> > >>>> > cheers, >>>> > >>>> > Nathan >>>> > >>>> > ps - re arctic methane - since this is mild approach, I doubt it would >>>> > be a big part of dealing with any emergency there, but if it were, it >>>> > could involve adding such a coating on top of the kind of recycled >>>> > plastic faux ice-floe idea that I've mentioned before in this >>>> > group.... >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > I got another UVA chemistry faculty (Lehmann) who has developed >>>> > perhaps the most sensitive way of reading methane, with dual lasers, >>>> > interested in helping me run some simple experiments. >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > >>>> > On Jul 26, 7:32 am, Andrew Lockley <[email protected]> wrote: >>>>> >> Creating OH radical is best done by leveraging existing processes. >>>>> >> The radical is too short-lived to be effectively distributed when >>>>> >> produced industrially, and energy costs are also too high. >>>>> >> >>>>> >> The NOx recycling reaction series was chosen by L Zhou et al in their >>>>> >> recent paper, as (in dry air) NOx is persistent and recycles. >>>>> >> >>>>> >> For the paper, >>>>> seehttp://www.atm.helsinki.fi/FAAR/reportseries/rs-109/abstracts/Luxi%20. >>>>> <http://www.atm.helsinki.fi/FAAR/reportseries/rs-109/abstracts/Luxi%20.> .. >>>>> >> >>>>> >> Biological processes are able to indirectly create NOx by nitrogen >>>>> >> fixation using symbiotic bacteria in root nodules. The plants can >>>>> >> then be burned to liberate NOx into the atmosphere. The Lupin is one >>>>> >> potential candidate, but other N2 fixers such as clover may also work. >>>>> >> This could additionally perhaps be used as a source of biochar. The >>>>> >> slight complexity is that NOx rains out in wet air, but the plants >>>>> >> need to be grown in wet soil. Haul costs are likely to be a >>>>> >> significant issue, therefore. >>>>> >> >>>>> >> One slightly 'far out' approach is to press ahead with the attempts to >>>>> >> make non-legumes capable of fixing N2 through GM. This would >>>>> >> revolutionize global agriculture, as well as giving a feedstock for >>>>> >> geoengineering - as the N2 fixation process is the chemical >>>>> >> underpinning of protein creation in crops. This isn't fanciful, and >>>>> >> lots of work is already being done. >>>>> >> >>>>> >> An alternative technique with a much more limited scope of application >>>>> >> is the addition of Br2 to create Br radical. This would need to be >>>>> >> done in clean, damp air overlying the oceans. There is an existing >>>>> >> 'hole' in the global OH shield east of Papua New Guinea, where this >>>>> >> technique could be applied.http://eprints.ifm-geomar.de/10069/ It is >>>>> >> one of the authors of this paper who suggested the Br technique to me. >>>>> >> >>>>> >> The downsides of creating NOx, as Zhou et al note, is that the both >>>>> >> NOx itself, and the trop O3, are both toxic and also GHGs in their own >>>>> >> right. It's not a pleasant solution to have to be considering. >>>>> >> >>>>> >> Readers should note the Kyoto controls on NOx, which have a beneficial >>>>> >> effect by potentially reducing forcing, but a negative indirect effect >>>>> >> by reducing OH radical production, which will become more significant >>>>> >> in a low OH, high CH4 atmos. However, it should also be noted that >>>>> >> locally high NOx concentrations are associated with different >>>>> >> chemistry which does not lead to the production of OH and the >>>>> >> consequential breakdown of methane. Therefore, industrial OH >>>>> >> controls, particularly in smoggy cities, are generally beneficial, >>>>> >> whereas in rural areas those same controls may have a positive RF >>>>> >> outcome. >>>>> >> >>>>> >> This is a very interesting field, and one that more assistance and >>>>> >> input is welcomed in. >>>>> >> >>>>> >> A >>>>> >> >>>>> >> On 26 July 2011 10:54, Sam Carana <[email protected]> wrote: >>>>> >> >>>>> >> >>>>> >> >>>>>> >> > Oliver Tickell wrote: >>>>>>> >> >> Another approach would be to enhance HO hydroxyl in the atmosphere - the >>>>>>> >> >> main destroyer of methane. I have no idea how to set about doing >>>>>>> this. It >>>>>>> >> >> could be helpful to reduce emissions that utilise existing >>>>>>> hydroxyl, such as >>>>>>> >> >> miscellaneous hydrocarbons. But the chemistry is complex and it is >>>>>>> hard to >>>>>>> >> >> strictly follow through any intervention to its end results! >>>>> >> >>>>>> >> > There are a number of methods that seek to reduce methane whilst >>>>>> still >>>>>> >> > in the water (microbes, bubbles, covering the water surface with >>>>>> white >>>>>> >> > plastic to capture the methane, etc). >>>>> >> >>>>>> >> > One problem is that, in many places (including in ESAS), waters are >>>>>> >> > shallow and there's little time for microbes to do their work, >>>>>> >> > especially when hydrates suddenly start releasing huge amounts of >>>>>> >> > methane. >>>>> >> >>>>>> >> > Therefore, it's crucial to also look at hydroxyl and I advocate two >>>>>> >> > types of feebates to help reduce emissions that compete for >>>>>> hydroxyl: >>>>>> >> > 1. Energy feebates (seeking to reduce emissions from power plants and >>>>>> >> > help electrify transport); and >>>>>> >> > 2. Fees on livestock products to fund biochar, which will reduce >>>>>> >> > methane, while encouraging pyrolysis and thus also reduce BC, VOC and >>>>>> >> > the like. >>>>>> >> >>>>>> >http://knol.google.com/k/sam-carana/the-way-back-to-280-ppm/7y50rvz99... >>>>> >> >>>>>> >> > As to enhancing hydroxyl in the arctic, here are some suggestions: >>>>> >> >>>>>> >> > - Tri-Air Developments has developed a technology that combines UV >>>>>> >> > light with extremely low levels of ozone and mixes it with volatile >>>>>> >> > hydrocarbons, to produce hydroxyls. This technology is used in >>>>>> Cirrus3 >>>>>> >> > devices that emit hydroxyls in rooms of less than 25m3 up to rooms in >>>>>> >> > excess of 500m3 (image below). Perhaps such technology could be used >>>>>> >> > at large scale in the Arctic to combat the methane menace. >>>>> >> >>>>>> >> > - Another method may be to use UV light for photolysis of hydrogen >>>>>> peroxide. >>>>> >> >>>>>> >> > - Using UV light to break down methane in the Arctic could possibly be >>>>>> >> > achieved by model airplanes, equipped with LiPo batteries and with >>>>>> >> > solar thin film mounted both on top of and underneath the wings. >>>>>> >> > Numerous such planes could navigate the Arctic by autopilot in >>>>>> summer, >>>>>> >> > when there are high concentrations of hydrogen peroxide and when the >>>>>> >> > sun shines 24-hours a day. Flying figure-8 patterns with the wings >>>>>> >> > under an angle could optimize capture of sunlight, keeping the >>>>>> planes >>>>>> >> > in the air, while using surplus energy to power UV lights. At the end >>>>>> >> > of summer, the planes could return home for a check-up and possible >>>>>> >> > upgrade of the technology, to be launched again early summer the next >>>>>> >> > year. >>>>> >> >>>>>> >> >>>>>> >http://knol.google.com/k/the-threat-of-methane-release-from-permafros... >>>>> >> >>>>>> >> > Cheers! >>>>>> >> > Sam Carana >>>>> >> >>>>>> >> > On Tue, Jul 26, 2011 at 1:44 PM, John Nissen <[email protected]> >>>>>> wrote: >>>>> >> >>>>>>> >> >> Thanks Oliver. >>>>> >> >>>>>>> >> >> I'm posting your comments to the geoengineering group with the >>>>>>> questions you >>>>>>> >> >> raise: >>>>> >> >>>>>>> >> >> 1. Could the CDM be used to fund, or help fund, our pilot project >>>>>>> to trial >>>>>>> >> >> various techniques for tackling the Arctic methane problem? Could it >>>>>>> >> >> subsequently fund deployment of selected techniques? >>>>> >> >>>>>>> >> >> 2. Is there any way to enhance HO hydroxyl in the atmosphere? >>>>> >> >>>>>>> >> >> Cheers, >>>>> >> >>>>>>> >> >> John >>>>> >> >>>>>>> >> >> --- >>>>> >> >>>>>>> >> >> On 25/07/2011 17:52, Oliver Tickell wrote: >>>>> >> >>>>>>> >> >> Certainly it makes sense to do something about large, concentrated >>>>>>> methane >>>>>>> >> >> emissions where it is realistic to capture the gas and burn it >>>>>>> off, or use >>>>>>> >> >> it for heat / power. >>>>> >> >>>>>>> >> >> Does the CDM currently provide credits for methane projects of >>>>>>> this type? I >>>>>>> >> >> believe it does for methane from pig farms etc so there is no >>>>>>> obvious reason >>>>>>> >> >> why it should not. >>>>> >> >>>>>>> >> >> Another approach would be to enhance HO hydroxyl in the atmosphere - the >>>>>>> >> >> main destroyer of methane. I have no idea how to set about doing >>>>>>> this. It >>>>>>> >> >> could be helpful to reduce emissions that utilise existing >>>>>>> hydroxyl, such as >>>>>>> >> >> miscellaneous hydrocarbons. But the chemistry is complex and it is >>>>>>> hard to >>>>>>> >> >> strictly follow through any intervention to its end results! >>>>> >> >>>>>>> >> >> Oliver. >>>>> >> >>>>>>> >> >> -- >>>>>>> >> >> Oliver Tickell >>>>> >> >>>>>>> >> >> On 25/07/2011 15:09, Veli Albert Kallio wrote: >>>>> >> >>>>>>> >> >> I think definitely that we can prevent on-shore methane >>>>>>> explosions, and >>>>>>> >> >> saturated methane laden water pockets that are approaching >>>>>>> nucleating point. >>>>> >> >>>>>>> >> >> There are 3 types of methane leaking: >>>>> >> >>>>>>> >> >> 1) generic leaking of methane from melting permafrost over large >>>>>>> areas that >>>>>>> >> >> provide widespread methane haze >>>>>>> >> >> 2) spot type ongoing methane leaking from permaforst or onshore >>>>>>> gas fields >>>>>>> >> >> that are losing their subterranean gas compression due to >>>>>>> ruptures. >>>>>>> >> >> 3) explosive methane eruptions (methane clatrates, Lake Cheko's >>>>>>> conical >>>>>>> >> >> basin gas field failure in Tunguska 1908 as river fell into gas >>>>>>> field and >>>>>>> >> >> drove methane out). >>>>> >> >>>>>>> >> >> No. 1 you cannot control. No. 2 depends on how big and focused the >>>>>>> leaking >>>>>>> >> >> is, there are vast bubbling spots, in Azerbaijan there are flaming >>>>>>> mountains >>>>>>> >> >> where gas comes out of rocks. These you can control. No. 3 can be >>>>>>> controlled >>>>>>> >> >> by method of Professor Michel Halbwachs. Often methane can be >>>>>>> spotted as a >>>>>>> >> >> very focused leak on sea floor which might be possible to cap. >>>>>>> So, I think >>>>>>> >> >> the idea is valid in certain cases, in other cases it may not be >>>>>>> workable. >>>>> >> >>>>>>> >> >> ________________________________ >>>>>>> >> >> Date: Mon, 25 Jul 2011 11:28:12 +0100 >>>>>>> >> >> From: [email protected] >>>>>>> >> >> Subject: Re: Arctic methane workshop, London, 15-16th October >>>>>>> CONFIRMED >>>>>>> >> >> To: [email protected] >>>>> >> >>>>>>> >> >> John, I think you are on a hiding to nothing trying to trap or >>>>>>> destroy the >>>>>>> >> >> methane. >>>>> >> >>>>>>> >> >> The reason is simple - the emissions are spread over such a vast >>>>>>> area of >>>>>>> >> >> many millions of sq.km <http://sq.km> . Even to trap and destroy >>>>>>> the methane emissions from >>>>>>> >> >> 1sq.km <http://1sq.km> would be a fantastically difficult and >>>>>>> expensive task. >>>>> >> >>>>>>> >> >> So you can simplify things by just ruling this one out at the >>>>>>> start! >>>>> >> >>>>>>> >> >> Oliver. >>>>> >> >>>>>>> >> >> -- >>>>>>> >> >> Oliver Tickell >>>>> >> >>>>>>> >> >> On 22/07/2011 18:29, John Nissen wrote: >>>>> >> >>>>>>> >> >> Dear all, >>>>> >> >>>>>>> >> >> In case you were not aware, the workshop, which was to have been 3-4th >>>>>>> >> >> September, is now going to be on 15-16th October. Here is the >>>>>>> background >>>>>>> >> >> and purpose of the workshop... >>>>> >> >>>>>>> >> >> A group of scientists and engineers (including myself) is deeply >>>>>>> concerned >>>>>>> >> >> about the potential of methane from thawing permafrost in the >>>>>>> Arctic to >>>>>>> >> >> cause irreversible, catastrophic and unsurvivable global >>>>>>> warming. Major >>>>>>> >> >> factors are the unexpectedly rapid retreat of sea ice [1] and the >>>>>>> >> >> unexpectedly large quantities of carbon which might be emitted as >>>>>>> methane >>>>>>> >> >> [2]. In June 2010 we wrote an open letter to Obama's scientific >>>>>>> adviser, Dr >>>>>>> >> >> John Holdren, suggesting action was urgently needed to address the >>>>>>> methane >>>>>>> >> >> issue [3]. Some sea ice experts, including Professor Peter >>>>>>> Wadhams in our >>>>>>> >> >> group, now reckon the Arctic Ocean will very likely become >>>>>>> seasonably ice >>>>>>> >> >> free this decade if there is no action to cool the Arctic. >>>>> >> >>>>>>> >> >> Recently Peter Wadhams has drawn my attention to work of Natalia >>>>>>> Shakhova >>>>>>> >> >> with Igor Semiletov on East Siberian Arctic Shelf (ESAS) - >>>>>>> particularly >>>>>>> >> >> concerning the present large emissions of methane and the >>>>>>> possibility of >>>>>>> >> >> release of much larger quantities "at any time". So we have been >>>>>>> wondering >>>>>>> >> >> whether anything can be done quickly to reduce this methane >>>>>>> threat. We >>>>>>> >> >> have been discussing possible action, and plan >>>>> >> >>>>> >> ... >>>>> >> >>>>> >> read more » >>>> > >>>> > -- >>>> > 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] >>>> <mailto:geoengineering%[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.
