No. See Robock's recent paper in the archives.
----- Original Message ----- From: "Andrew Lockley" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; "geoengineering" <[email protected]>; <[EMAIL PROTECTED]> Sent: Wednesday, December 10, 2008 9:38 AM Subject: Re: Fw: [geo] Re: delivering aerosols Won't this cause severe acid rain? A 2008/12/10 Alvia Gaskill <[EMAIL PROTECTED]>: > H2S oxidation chemistry: > > http://jan.ucc.nau.edu/~doetqp-p/courses/env440/env440_2/lectures/lec37/lec37.htm > > > "Sulfur is released to the atmosphere as either hydrogen sulfide or sulfur > dioxide. Both forms are toxic gases that are primary air pollutants. > Hydrogen sulfide is oxidized to sulfur dioxide in a three step process as > shown in Figure 37.2. Note that the hydroxyl radical is responsible for > initiating the transformation from hydrogen sulfide to sulfur dioxide." > > > > The additional water vapor could add to PSC formation or it could react > with > the SO2 to produce aerosol. The amount of water vapor added by H2S > precursor injection is far less than from a typical volcanic eruption and > would likely have no impact on stratospheric warming other than that from > the aerosol itself. Still, it would be important to see the numbers for > possible impacts. > > The water vapor would also serve to act as a "reservoir species," typing > up > the hydroxyl radical and limiting its impact on ozone decomposition. HO > is > also conserved in this series of reactions, so addition of H2S wouldn't > increase the quantity of reactive hydroxyl. > > http://www.ccpo.odu.edu/SEES/ozone/class/Chap_5/5_4.htm > > > > "The hydrogen species on the righthand side of these reactions (i.e., H2O, > HNO3, and HNO4) are known as reservoir species, which are chemical > compounds > that store (like a reservoir) a particularly species in a nonreactive > form. > These species act as stores of hydrogen, locking up or sequestering HOx > and > preventing its participation in the catalytic cycle outlined above. H2O, > HNO3 and HNO4 react very slowly with odd oxygen. When HOx is tied up in > one > of the reservoir species, therefore, it is not important in the loss of > odd > oxygen." > > > > > > ----- Original Message ----- > From: John Nissen > To: [EMAIL PROTECTED] ; geoengineering > Cc: [EMAIL PROTECTED] > Sent: Wednesday, December 10, 2008 6:39 AM > Subject: Re: Fw: [geo] Re: delivering aerosols > > It frightens me that we are still asking such questions about the > chemistry, > and that we still do not have answers on delivery and particle size for > our > SRM (solar radiation management). > > Surely we should have been doing some experiments with different means of > delivery to find out what actually happens in terms of particle size, > clustering, etc. Perhaps we can also do experiments re Oliver's concerns. > > And do we know quantitatively what the heat-trapping effect of aerosol > clouds/haze will be, especially in the Arctic winter? Perhaps we should > aim > for the aerosol to remain up for a few months rather than a year or two. > > At present, we seem to leave everything to modelling. Yet SRM is our > best > chance, perhaps only chance, to save the Arctic sea ice. It is > desperately > urgent to move onto concerted development of SRM techniques, with a view > to > rapidly ramping up deployment over the next two or three Arctic summers > (April-Sept). Every year that we delay can add significantly to the > albedo > effect that we are trying to counter [1], and significantly reduce our > chance of success, let alone giving ourselves leaway to deal with any > unexpected negative side-effects. > > Cheers, > > John > > [1] The albedo effect would approximately double between now and when > the the sea ice is nearly gone at end of summer, which could be 2013 or > earlier according to some experts. Averaged over the year, the albedo > effect, as ice turns to water, is about 90 Watts per square metre > neglecting > cloud, and 30 W/m-2 if you allow for cloud (according to Jeff Ridley's > calculations). Compare net anthropogenic forcing of about 1.6 W/m-2 and > you > see what we are up against. I suspect that SRM techniques will have to be > applied more widely than just the Arctic ocean to achieve the necessary > total cooling of the region. > > > > ----- Original Message ----- > From: "Oliver Wingenter" <[EMAIL PROTECTED]> > To: "geoengineering" <[email protected]> > Sent: Wednesday, December 10, 2008 5:50 AM > Subject: Re: Fw: [geo] Re: delivering aerosols > > Dear Alvia, > > If H2S applied to the stratosphere, would the additional hydrogen > impact i) HOx chemistry and therefore ozone loss and ii) increased > water vapor which is a greenhouse gas and could lower the threshold > for PSC formation? > > Oliver > > On Dec 9, 10:32 am, "Alvia Gaskill" <[EMAIL PROTECTED]> wrote: >> 1. I think that at a minimum, the release altitude has to be 65,000 ft >> and >> at most, 90,000 ft as you don't gain much residence time above 90,000 ft. >> The aerosol just starts to descend. >> >> 2. The preferred precursor liquid is H2S, since that reduces the quantity >> required by a factor of 2 if SO2 were used. >> >> 3. The figure of 1Tg/yr would probably be a good starting point as if >> such >> a >> program were run for several decades, levels on this order would be >> approached. Of course, all those other issues about what happens to the >> gas >> after it is released still have to be addressed, but getting it there is >> job >> no. 1 >> >> 4. The problem of unit mass is the same one faced by the NAS-92 panel >> when >> considering how many shells containing dust would have to be fired. If >> you >> need to get 1 million tons of H2S into the stratosphere per year, then >> that >> works out to 2700 tons per day. If a shell can hold 1000 lbs (which I >> think >> will turn out to be about the limit for any type design), then that would >> require 5500 shots per day or 2 million/yr. That means lots of guns as >> they >> will wear out pretty fast. The fuel per ton issue is probably valid, but >> the planes already exist and can be repaired as needed. Dispersal is a >> key >> problem with this and with tanks carried by airplanes as the liquid has >> to >> quickly turn into a vapor. If the drops are too large, that may cause >> much >> of it to simply fall rapidly. On the otherhand, if it is released in an >> explosion, in the way that artillery shells usually work, then there >> might >> be sufficient dispersal and also conversion to SO2 through oxidation. All >> these issues aside, I think the number of shots is the biggest obstacle. >> And if you've ever had to work with a bunch of big shots, you know what >> I'm >> talking about. That was a joke. >> >> ----- Original Message ----- >> From: "Roger Angel" <[EMAIL PROTECTED]> >> To: <[EMAIL PROTECTED]> >> >> Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; >> <[email protected]> >> Sent: Tuesday, December 09, 2008 11:02 AM >> Subject: Re: [geo] Re: delivering aerosols >> >> > Re gun delivery, >> > I have a student who working on delivering liquid aerosol precursor >> > such >> > as liquid SO2 to ~ 25 km altitude with optimized vertical pointing >> > guns. >> > We are looking at the basic physics of acceleration, pressure >> > containment >> > etc and the energy budget for various options of combustion, air >> > pressure >> > and magnetic force to do the acceleration. The acceleration has to be >> > relatively low to keep down the thickness and mass of the steel launch >> > vessel, leading to a vertical acceleration path of about 100 m. For >> > acceleration by gas pressure, which is about equal to the pressure in >> > the >> > liquid, the barrel will be quite lightly built, not like an artillery >> > gun. >> > The alternative of magnetic acceleration gives the best energy >> > efficiency >> > but will take longer to develop. Any gun method is likely to use much >> > less fuel per ton delivered than aircraft delivery, with far less wear >> > and >> > tear. >> >> > Questions to the group - what is the preferred precursor liquid and >> > height? Is a million tons a year about the right delivery rate? What >> > unit >> > mass would be best? Will it be necessary to disperse the liquid by a >> > small explosive charge, like a firework? An optimized gun delivery >> > system >> > would be fairly quick to develop, prototype and test, for perhaps a >> > hundred million dollars. >> >> > Roger Angel >> >> > Alvia Gaskill wrote: >> >> Artillery shells cannot hold very much material, requiring an >> >> excessive >> >> number of shots be fired. If liquid H2S were to be loaded into such a >> >> shell, it also might not disperse sufficiently. There are also no guns >> >> available for firing the shells. NAS-92 looked at their potential for >> >> firing dust containing shells, but the same concerns apply. >> >> >> Atmospheric nuclear testing was banned in the 1960's and for good >> >> reason. >> >> Radiation disperses and enters the environment causing mutations, >> >> cancer >> >> and death. That's why we have the IAEA, the non proliferation treaties >> >> and UN sanctions against Iran. There is no safe way to use nuclear >> >> weapons. >> >> >> Volcanic eruptions up to the scale of Pinatubo are relatively benign >> >> in >> >> their side effects. Tambora and Laki-sized eruptions disrupted the >> >> global climate and killed thousands of people. A Yellowstone or Toba >> >> eruption would be like a global nuclear war. It would kill almost >> >> everyone. Volcanoes also don't release large amounts of radiation. >> >> >> ----- Original Message ----- >> >> From: "Andrew Lockley" <[EMAIL PROTECTED]> >> >> To: <[EMAIL PROTECTED]> >> >> Cc: <[EMAIL PROTECTED]>; <[email protected]> >> >> Sent: Monday, December 08, 2008 10:13 AM >> >> Subject: [geo] Re: delivering aerosols >> >> >> Please don't make personal digs just because I suggested an idea that >> >> may not work. >> >> >> Why is a nuclear bomb worse than a volcano anyway? >> >> >> And what about artillery as a method? >> >> >> 2008/12/8 Alvia Gaskill <[EMAIL PROTECTED]>: >> >> >>> The only people seriously considering using nuclear weapons to put >> >>> lots >> >>> of >> >>> particulate matter into the stratosphere live in the tribal areas of >> >>> Pakistan. Alan Robock showed what happens if India and Pakistan play >> >>> nuclear ping pong with their meager arsenals. The particulate matter >> >>> carried into the stratosphere absorbs enough solar energy to heat the >> >>> stratosphere to the point where reactions that destroy ozone are >> >>> maximized. >> >>> The net result is that everyone and everything on the surface of the >> >>> Earth >> >>> is killed by UV radiation. Now you wouldn't want that, would you >> >>> Andrew? >> >>> Your organization is called Friends of the Earth, isn't it, although >> >>> the >> >>> acronym FOE is a little disturbing. >> >> >>> I've looked at the delivery system issue (see the group files for >> >>> some >> >>> of >> >>> what I've written) and concluded that airplanes and balloons could be >> >>> used. >> >>> To get precursor gas to circulate globally, it must be released above >> >>> 53,000 >> >>> ft, the boundary between the tropical tropopause and the >> >>> stratosphere. >> >>> In >> >>> fact, due to the fall rates of aerosol, it should be released at >> >>> above >> >>> 65,000 ft to guarantee at least a one-year residence time in order to >> >>> make >> >>> it practical. The B-52, the KC-135 and other large subsonic aircraft >> >>> cannot >> >>> fly this high, their ceilings right at around 50,000 ft. To fly as >> >>> high >> >>> as >> >>> would be necessary and carry enough payload to make it worthwhile >> >>> would >> >>> require supersonic aircraft. I settled on the F-15c with a ceiling of >> >>> around 65,000 and the ability to carry about 8 tons of payload of >> >>> which >> >>> half >> >>> could be the gas. >> >> >>> You are correct about the balloons in that using hydrogen as the >> >>> lifting >> >>> gas >> >>> instead of helium doubles the lifting capacity. Using H2S instead of >> >>> SO2 >> >>> doubles the precursor quantity that can be carried again as well. So >> >>> balloons containing hydrogen and H2S within the envelope of the >> >>> balloon >> >>> could deliver the gas to the stratosphere in the quantities required >> >>> and >> >>> to >> >>> much higher altitudes as well, up to 120,000 ft. The technology to >> >>> inflate >> >>> and recover payloads from large football stadium sized stratospheric >> >>> balloons exists today and has been used since the 1940's to deliver >> >>> payloads >> >>> of up to 8000 lbs to 120,000 ft and recover them. >> >> >>> The real issue about the delivery systems is whether or not the gas >> >>> will >> >>> form the proper sized aerosol using the existing water vapor in the >> >>> stratosphere. This will requre field tests to determine its >> >>> feasibility >> >>> as >> >>> well as whether gas can be released from tanks quickly enough to >> >>> vaporize in >> >>> the time that the planes can spend in flight at these altitudes, >> >>> probably >> >>> about an hour. Balloon residue can be addressed through a collection >> >>> program and I doubt the residue would come close to that already >> >>> floating in >> >>> the middle of the Pacific from land based plastic waste. Alan >> >>> Robock's >> >>> statement in his AMS slides that "billions of weather balloons would >> >>> be >> >>> required" is only accurate if weather balloons were used. High >> >>> altitude >> >>> stratospheric balloons are not weather balloons. >> >> >>> ----- Original Message ----- >> >>> From: "Andrew Lockley" <[EMAIL PROTECTED]> >> >>> To: <[EMAIL PROTECTED]> >> >>> Cc: <[email protected]> >> >>> Sent: Monday, December 08, 2008 6:14 AM >> >>> Subject: [geo] Re: delivering aerosols >> >> >>> As they are just converted old bombers you could easily convert a >> >>> different bomber to do the job. B52s are an obvious choice as there >> >>> are loads lying about and they are very large, reducing the costs. I >> >>> think they fly very high. >> >> >>> A >> >> >>> 2008/12/8 <[EMAIL PROTECTED]>: >> >> >>>> These planes cannot reach the sub-stratosphere at all. >> >>>> Gregory >> >> >>>> Has anyone looked at using firefighting planes to deliver aerosol >> >>>> particles? >> >> >>>> -----Original Message----- >> >>>> From: Andrew Lockley <[EMAIL PROTECTED]> >> >>>> To: geoengineering <[email protected]> >> >>>> Sent: Sun, 7 Dec 2008 5:46 pm >> >>>> Subject: [geo] delivering aerosols >> >> >>>> Has anyone looked at using firefighting planes to deliver aerosol >> >>>> particles? These are designed to spray powder. There are a lot of >> >>>> them about in Northern latitudes, and for much of the year they >> >>>> really >> >>>> don't do a lot. >> >> >>>> I've seen several other methods, all of which have disadvantages: >> >>>> 1) Space lift - still scifi >> >>>> 2) Balloons - could work, but would have to be hydrogen, not helium >> >>>> due to the volumes needed. Unless the balloons are programmed to >> >>>> deflate and float back down, there will be a lot of 'litter'. To get >> >>>> a decent payload, a very large flammable balloon would be needed. >> >>>> 3) artillery - possibly useful, but may be a lot more polluting, >> >>>> expensive and energy intensive than a plane. >> >> >>>> ________________________________ >> >>>> Listen to 350+ music, sports, & news radio stations – including >> >>>> songs >> >>>> for >> >>>> the holidays – FREE while you browse. Start Listening Now! > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
