[geo] Re: Comments on Irvine et al. (2019) by Alan Robock
Alan Thanks for taking the time to write this. Responses below. Look forward to discussing in person, best over a beer. (N.B., i don't get emails from this-just too much inbox--so pls anyone feel free to email me directly with posts...) Yours, David First of all, I want to make clear that I completely agree with David Keith that mitigation is the solution to the global warming problem and we have to work urgently to switch our energy system away from fossil fuels, that we need much more research on solar geoengineering, and that we should not ever do solar geoengineering until we have a much better understanding of the risks it might pose as compared to the risks of not doing it. I suspect you agree, but nevertheless I need to say it: Mitigation is necessary, but mitigation is *not* “the solution”. Cutting emissions to zero stops putting CO2 in the air. The CO2 and climate risk are still there. We need adaptation. But adaption is not *the solution*. Neither is solar geo. Neither is carbon removal. Complex problems like climate rarely have a single solution. The overarching question here is should solar geo be part of the solution? My answer is I don’t know. But there is enough reason to think it should be that I think serious research makes sense. But I disagree with his framing of this new paper. In his March 11 tweet he said, “New paper with Kerry Emanuel and a GFDL team in @NatureClimate, using high-resolution model to test which regions would be made worse off by solar geoengineering--find that no region is made worse off in any of the major climate impact indicators we examined.” He fails to mention that many places on Earth might be worse off if we follow their scenario if we consider more than just temperature and precipitation minus evaporation. In any case, “worse” as compared to what? If we rapidly begin mitigation now, that is rapidly reduce our CO2 emissions to zero by switching our power to wind and solar, we will be much better off than a business-as-usual future, or one with geoengineering. I don’t think it is useful or correct to imply that geoengineering is a good or safe idea. Guilty as charged. The tweet is too simple. But I think it’s clear from my work and many other tweets in about this paper that I and other authors (see Kerry’s interview <https://www.wbur.org/radioboston/2019/03/11/aerosols-global-warming>) know there will--of cours--be impacts of any solar geo method. There is *no *way geo can be risk free. Quibble: It’s not fair for you to say “just temperature and precipitation minus evaporation”, as you now we did look at more than T and P-E, we did Tmax, Pmax, P,and some look at seasonal, and Tropical Cyclone intensity. But, quibble aside – there is lots more to do. For example, it would be nice to do a long multi-century run and look at droughts. More important. You assert “If we rapidly begin mitigation now, that is rapidly reduce our CO2 emissions to zero by switching our power to wind and solar, we will be much better off than a business-as-usual future, or one with geoengineering.” I don’t think this is supported by data. There is *no doubt* that mitigation is far better than BAU. But it’s quite possible that mitigation plus some solar geo is less risky than mitigation alone. Or, maybe not. But I don’t know. And I don’t know how you can be sure. This is the essence of the debate. Irvine et al. (2019) utilized a high-resolution climate model from GFDL to do some stratospheric geoengineering experiments, but the results they got must be considered in the context of the limitations of the work. Because they mimicked stratospheric geoengineering by turning down the solar constant rather than modeling stratospheric aerosols, they ignored a large number of potential impacts, including more diffuse radiation, heating of the stratosphere, and impacts on stratospheric ozone. These latter two factors would change atmospheric circulation as well as affect the potential intensity of tropical cyclones. And the changes in circulation will change the temperature and precipitation patterns that result. It also must be kept in mind that they considered only one particular scenario of stratospheric geoengineering. And there is no way to do what they modeled, as we cannot turn down the Sun. The technology to create an aerosol cloud in the stratosphere does not currently exist. Various designs have been described that would cost $50,000,000,000 to $200,000,000,000 (50-200 billion dollars) per year to implement, and which would result in significant increases in acid rain as well as a host of other possible risks. (This calculation came from the estimates of Robock et al. (2009), McClellan et al. (2010, 2012), Smith and Wagner (2018), and deVries et al. (2018) of how much it would cost to construct and operate planes to deliver enough SO2 or H2SO4 to the strato
[geo] Re: Cheap Carbon Capture
I don’t normally monitor this group but someone suggest that respond to this comment so here goes… 1. Di Marco is entirely correct that we can’t make fuels that are precisely carbon neutral with the gas-fired system. Our estimate is that fuels made using that system would have WTW carbon intensities of roughly 30 gCO2/MJ. This is still better than most biofuels and about three times better than typical fossils but it’s not zero. David Robert’s Vox article got this right. 2. As we hint in the paper we are developing all-electric options for the fuels production. 3. I agree that fossil prices will fall, under life-cycle standard regs like LCFS our competition is not directly fossils but rather other options: H2, NH3, and batteries. We think air-to-fuels does very well against that competition as a long-term pathway to power heavy transportation. -David On Friday, 15 June 2018 17:03:40 UTC-4, Leon Di Marco wrote: > > > > *Perhaps my last post was rather too hard on Christopher Preston, who is > not an expertHere is an illustration of the dubious nature of some of the > claims that have been made, using the attached paper just published in > Joule by Keith et al , entitled A Process for Capturing CO2 from the > Atmosphere, which has been the subject of some publicity. U**nder the > heading Context and Scale, ** the paper gives this description - * > *"An industrial process for large-scale capture of atmospheric CO2 (DAC) > serves two roles. First, as a source of CO2 for making carbon-neutral > hydrocarbon fuels,"* > > *The cover page shows an infographic illustrating 1 tCO2 being captured > by a DAC machine, producing a 1.3-1.5 t stream of CO2 intended for "Fuels > or Sequestration" . The source of the additional CO2 is explained **in > the body of the paper at page 2-* > *"* > *At full capacity, this plant captures 0.98 Mt-CO2/year from * > *the atmosphere and delivers a * > *1.46 Mt-CO2/year stream of dry CO2 at 15 MPa. The additional 0.48 > Mt-CO2/year is produced by on-site combustion of natural gas to meet all > plant thermal and electrical requirements."* > > *If the product from this machine is intended to be fuel, 1/3 of the CO2 > output comes from burning natural gas, and thus the fuel cannot be carbon > neutral. Alternatively, if the CO2 is buried in sites intended for > enhanced oil recovery, then there will be an additional carbon footprint. >A combination of both (by burying 1/3 of the CO2) will still have > consequences for the carbon footprint of the fuel.* > > * The main message from the paper is the formal refutation of the results > from the report on the cost of DAC produced by the APS in 2011. But that > message has long been overtaken by the findings from several commercial > players who have been working on DAC . Beyond that its message is > controversial and smacks of commercial hype. * > > *It is possible to produce carbon negative power using a plant using > natural gas, and even carbon negative synthetic liquid fuels ( if that is > what is required) but the likelyhood is that low cost carbon offsets from > DAC will be used to cancel the emissions created by burning fossil fuels. > The cost of oil will fall as demand reduces and that will make it difficult > for synthetic fuels to survive.* > > > > > > > On Thursday, June 14, 2018 at 10:10:54 PM UTC+1, Christopher Preston wrote: >> >> A few thoughts on last week's good news about the potential for much >> cheaper DAC. >> >> >> https://plastocene.com/2018/06/14/catching-carbon-why-cheap-still-comes-with-a-cost >> > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
[geo] Re: [CDR] The International Conference on Negative CO2 Emissions » 22-24 May 2018
Peter I’m sorry you’re frustrated. I don’t think your interpretation is entirely fair. It would be ridiculous to claim that solar geoengineering is “necessary”. I did not make that claim here and I believe I’ve been consistent on this over years in writing and speaking. I don’t believe I said anything to contradict that view in this interview. It’s true I did not specifically say in this interview that this was not true. But note that this interview this was tightly edited and omitted many things I often say about governance and about context including mitigation and carbon removal. For a longer unedited video that does mention carbon removal see: https://www.technologyreview.com/video/609398/the-growing-case-for-geoengineering/ I have been clear consistently that solar geoengineering has substantial risks, that it is, at best, a partial supplement to emissions reductions. Here’s how I see the trade-off between emissions reductions, carbon removal, and solar geoengineering. Emissions reductions are necessary if we want a stable climate. If we try to continue emissions and offset them with increasing solar geoengineering the world will walk further and further away from the current climate with higher and higher risks. One could, in principle get a stable climate, by continuing emissions and offsetting them with carbon removal. But I fail to see why it would make economic or environmental sense to have massive carbon removal (with its attendant costs and environmental impacts) while we still have massive emissions. If there is truly a low impact way to do carbon removal that is significantly cheaper than emissions reductions, then I would change my view on this. (Yes, I know you believe you can do carbon removal at some low number like 30 or $50 a ton. I truly hope you’re correct. I simply haven’t seen the evidence yet.) While emissions are high I don’t believe there is a meaningful distinction between emissions mitigation and carbon removal. The climate can’t tell the difference between a ton not emitted in a ton emitted and recaptured. So, while emissions are high, I think we should only put significant effort into large-scale deployment of carbon removal if it is cheaper than other methods of reducing emissions, or if it has lower environmental impacts and roughly the same cost. Once emissions get down towards zero carbon removal provides a unique ability to reduce concentrations. Once emissions get to zero carbon removal can do something that can’t be done by emissions mitigation or solar geoengineering. That’s part of the reason I’m very proud to have worked on carbon removal from my early work on BECCS (early papers, first PhD of the topic) to my work at Carbon Engineering). I would therefore like to see serious effort to developing carbon removal even if it is not now cheaper or otherwise better than emissions reduction. And serious development will entail limited deployment. It makes sense to do this during the time emissions are high to buy the option for net negative emissions once emissions get towards zero. Finally, solar geoengineering may provide a way to substantially reduce climate risks during a carbon concentration peak. A peak defined by continued positive emissions on the front and by carbon removal on the far side. Finally, note that, contrary to your assertion, solar geoengineering does in fact provide some significant reduction in carbon concentrations . Peter, I think were roughly on the same side. I think the work you’re doing is terrific. Yours, David N.B., I am not subscribed to this list so please email me or post on twitter if you want to continue the conversation. On Sunday, 19 November 2017 11:34:14 UTC-5, Peter Eisenberger wrote: > > David Keith was on TV and did what I have expressed concern about > generally about the advocacy for SRM > He accepted the framework that we will fail to address the carbon > emissions reduction targets , failed to mention the CDR > option he himself helped pioneer and then pushed off concerns expressed > about doing SRM by saying doing nothing > also has risks ( not even mentioning that acidification of the ocean will > continue for sure and the continuing buildup of co2 etc ) . But most > importantly he supported the choice as being between doing nothing or doing > SRM which as a previous comment pointed out will be embraced by those who > want to do nothing that doing this will enable us to avoid the adverse > impacts of climate change and thus is acceptable as a response to climate > change threat > > My general point has been and continues to be that if us scientists allow > our advocacy for a particular approach to determine what we say and not > discipline ourselves with > a overall coherent approach we will become (are) part of the problem and > not part of the solution >
[geo] Postdocs in solar geoengineering
Please forgive the mass mailing. I am looking to recruit couple of postdocs to work on solar geoengineering. I am particularly interested in people with a background in atmospheric science and chemistry, but also interested in an applicant from the social sciences. For star quality applicants, the Harvard Environmental Fellows Program <http://environment.harvard.edu/environmental-fellows-program> gives fellows, independence, good pay, and access to a broad set of faculty across campus. It’s deadline is 13th January (next Wednesday). If you know anyone who might be interested and suitable please point them my way ASAP. ( http://environment.harvard.edu/environmental-fellows-program). N.B., As Alan announced, in a small step to professionalizing work in this field several colleagues and I got a Gordon Conference on Solar Geoengineering approved, with the first meeting to be held in 2017. Happy New Year, David *David Keith* Gordon McKay Professor of Applied Physics, School of Engineering and Applied Sciences (SEAS); and, Professor of Public Policy, Kennedy School of Government, Harvard University david_ke...@harvard.edu www.keith.seas.harvard.edu@DKeithClimate Executive Chairman, Carbon Engineering www.carbonengineering.com -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
[geo] 2 new papers: solid aerosols and liablity
Here two new papers that may be of interest to the group. Debra K. Weisenstein and David W. Keith. (2015). Solar geoengineering using solid aerosol in the stratosphere. Atmospheric Chemistry and Physics Discuss., 15: 11799-1185. www.atmos-chem-phys-discuss.net/15/11799/2015/ There been a whole sequence of papers examining the possibility of solid aerosols for solar geoengineering the stratosphere, but none have look seriously at the fact that solid aerosols will interact with each other and with the background sulfate. We show that, for a given amount of radiative forcing, solid aerosols *might* be able to reduce some environmental risks: ozone, diffuse light, and heating of the lower stratosphere. I showed figures from the work in my longnow talk: http://longnow.org/seminars/02015/feb/17/patient-geoengineering/ Joshua B. Horton, Andrew Parker, and David Keith. (2015). Liability for Solar Geoengineering: Historical Precedents, Contemporary Innovations, and Governance Possibilities. NYU Environmental Law Journal, 22: 225-273. The absence of liability regimes is sometimes assumed to be a showstopper for solar geoengineering. We examine a set of international liability regimes mostly associated with environmental risks, and suggest that there is a broad legal and historical precedent that might serve as a basis to develop a regime for solar geoengineering. Papers are here: http://www.keith.seas.harvard.edu/srm-papers/ -- You received this message because you are subscribed to the Google Groups geoengineering group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
[geo] 2 new papers: solid aerosols and liablity
Here two new papers that may be of interest to the group. Debra K. Weisenstein and David W. Keith. (2015). Solar geoengineering using solid aerosol in the stratosphere. Atmospheric Chemistry and Physics Discuss., 15: 11799-1185. www.atmos-chem-phys-discuss.net/15/11799/2015/ There been a whole sequence of papers examining the possibility of solid aerosols for solar geoengineering the stratosphere, but none have look seriously at the fact that solid aerosols will interact with each other and with the background sulfate. We show that, for a given amount of radiative forcing, solid aerosols *might* be able to reduce some environmental risks: ozone, diffuse light, and heating of the lower stratosphere. I showed figures from the work in my longnow talk: http://longnow.org/seminars/02015/feb/17/patient-geoengineering/ Joshua B. Horton, Andrew Parker, and David Keith. (2015). Liability for Solar Geoengineering: Historical Precedents, Contemporary Innovations, and Governance Possibilities. NYU Environmental Law Journal, 22: 225-273. The absence of liability regimes is sometimes assumed to be a showstopper for solar geoengineering. We examine a set of international liability regimes mostly associated with environmental risks, and suggest that there is a broad legal and historical precedent that might serve as a basis to develop a regime for solar geoengineering. Papers are here: http://www.keith.seas.harvard.edu/srm-papers/ -- You received this message because you are subscribed to the Google Groups geoengineering group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
[geo] Self promo: Temporary, moderate, and responsive == patient
Here's a new(ish) paper and related talk: David W. Keith and Douglas G. MacMartin. (2015) A temporary, moderate and responsive scenario for solar geoengineering http://keith.seas.harvard.edu/papers/174.Keith.MacMartin.ATemporaryModerateandResponsiveScenarioforSolarGeoengineering.pdf . Nature Climate Change, DOI: 10.1038/NCLIMATE2493. The paper is available through the link above. Here's video of a talk I gave at Long Now foundation. Stewart Brand gave me the title, Patient Geoengineering. This talk includes longer, more visual version of the argument in the paper mentioned above. http://longnow.org/seminars/02015/feb/17/patient-geoengineering/ David -- You received this message because you are subscribed to the Google Groups geoengineering group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
[geo] Opporties @ Harvard
I am growing my research group at Harvard. Here are a few opportunities that might interest people on this list: Opportunities 1. The Harvard Center for the Environment has a great fellowship program http://environment.harvard.edu/environmental-fellows-program for post-docs. It’s a high-profile competitive program that gives recipients lots of freedom and a good community. 2. I will be taking at least one fellow through the Science Technology and Public Policy http://belfercenter.ksg.harvard.edu/project/44/science_technology_and_public_policy.html?page_id=348 program at the Belfer Center http://belfercenter.ksg.harvard.edu/index.html at the Kennedy School. These fellowships generally for post-docs, but they can be awarded to people without doctorates who have strong track-records in public policy work. 3. I also hire post-docs directly. However I get lots of inquiries and generally only pay attention if I get recommendations from someone I know. 4. Finally, there is a new Kennedy School fellowship for junior faculty or unusually qualified post-docs, the Louis Bacon Environmental Academic Fellow program. It provides full funding for one year’s residence at the Kennedys school. Let me know if you are interested. I am also funding researchers who want to visit for a few weeks. We expect to host an overlapping set of visitors working on solar geoengineering in May-June 2015. David David Keith Gordon McKay Professor of Applied Physics, School of Engineering and Applied Sciences (SEAS); and, Professor of Public Policy, Kennedy School of Government, Harvard University david_ke...@harvard.edu www.keith.seas.harvard.edu -- You received this message because you are subscribed to the Google Groups geoengineering group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
RE: [geo] Your Vector diagram
Andrew A few comments in response to this and the subsequent comment by 1. This vector representation is useful way to think about trade-offs when the climate response to CO2 and SRM is reasonably linear. This stuff is published as: Juan Moreno-Cruz, Katharine Ricke and David W. Keith. (2011). A simple model to account for regional inequalities in the effectiveness of solar radiation management. Climatic Change, doi: 10.1007/s10584-011-0103-z. (PDF)http://www.keith.seas.harvard.edu/papers/131.Moreno-Cruz.Inequality.SRM.e.pdf. Despite the hype about nonlinearity, models are quite linear in the region of interest, see the appendix to the paper. 2. I was surprised by our results. I expected the trade-offs to be much stronger. Doing this work pushed me to realize that SRM can do a substantially better job of compensating CO2-driven climate change than I had expected. (Of course, it does nothing about the geochemical impacts of CO2 such as ocean acidification.) 3. Yes, you can consider quantities other than temperature and precip; and quantities like soil moisture are certainly important. 4. Stephen Salter imply that these results were somehow particular to stratospheric sulfates, saying: I think that you must be referring to geo-engineering with stratospheric sulphur. With tropospheric salt you can vary precipitation in both directions by choosing the time and place to spray. This analysis is applicable to both. It is certainly true that if sea salt aerosol can be effectively used to alter cloud albedo over large areas--a proposition which is still quite uncertain--then it could be used to reduce (them eliminate) the trade-offs. We looked at exactly this in a more recent paper examining how trade-offs can be reduced if you were able to adjust the intensity of SRM forcing at different locations in seasons: Douglas G. MacMartin, David W. Keith, Ben Kravitz, and Ken Caldeira. (2012). Managing tradeoffs in geoengineering through optimal choice of non-uniform radiative forcing. Nature Climate Change, doi: 10.1038/NCLIMATE1722. (PDFhttp://www.keith.seas.harvard.edu/preprints/158.MacMartin.etal.ManagingTradeoffsThroughNonRadForc.p.pdf). Note that this paper explicitly looks at something people in this blog often ask about which is the ability to tune SRM to focus on restoring Arctic sea ice. 5. Finally, I do not understand your argument about soil moisture. Evaporation always equals precipitation the global mean. All else equal-- and it probably will not be--one expects variability to go down (not up) as you weaken the hydrological cycle. So my back of the envelope physics points the opposite way to yours. We look at this in one of the papers with Kate Ricke and found that at least the one case we looked at variability did go down. Of course, model do not equal reality. Yours, David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Andrew Lockley Sent: Monday, November 26, 2012 7:08 AM To: David Keith; geoengineering Subject: [geo] Your Vector diagram David I remember the excellent vector diagram lecture you gave at Oxford. In it you represented temperature and precipitation on a vector.diagram and showed that both cannot be simultaneously corrected exactly by geoengineering, but that the mismatch was small. However, that would leave us in a world which was either slightly drier or slightly warmer than in a non-geoeng world - or a combination of both. My concern is that things might be a bit more serious than that. If we consider a warmer world with the same level of precipitation, the surface evaporation world be higher and the relative atmospheric humidity would (I think) be lower. As a result, soil wetness may be very much lower, as evapotranspiration would be higher. If rainfall patterns were perturbed, we might additionally get more variability in both wetness and precipitation. So we could end up in a world with much drier soils, and possibly heavier storms, too. Should your vectors therefore be soil wetness vs temperature, not precipitation vs temp? Making a bad call on this could really hit agricultural outputs. A -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.commailto:geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.commailto:geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] Cost analysis of stratospheric albedo modification delivery systems (ERL) Open Access
Andrew Answers to your questions about the our recent URL paper on stratospheric albedo modification delivery systems. Q: Isn't this just a reformatted version of the Aurora flight report? A: Essentially yes. The online supplemental information is the Aurora report, the paper is newly written but has relatively little view analysis. The paper puts the report in an archival peer-reviewed journal. We made minor improvements in response to review but nothing fundamental. We could have kept the report to ourselves until publication, but because our views about the importance of openness in this field we decide to release the entire report when it was completed following our internal peer-review. Q: it ignores gas guns (which are half the price in $/kg of solid-propellant guns) and contradicts SPICE balloon cost estimates. It works up aircraft way more than other tech, leading to unsurprisingly lower cost estimates of these technologies. Coming up with low prices for worked up tech seems a common thread in papers. A: This seems to me a very odd criticism of this paper. Unlike (to my knowledge) any other paper we examined all the different options in our scope using the same costing assumptions and industry-standard cost estimating relationships (CERs). I am not aware that the SPICE project has done anything similar. We did not come into it with any particular bias towards airplanes and in practice we spent a lot of time on hybrid airships and on the balloon with hose option because analysis there was relatively harder to do. If you discount the section on existing aircraft which seems fair since there are no alternative options that are as ready to go, the section on new aircraft is not substantially longer than the sections on hybrid airships or the hose option. Finally it seems like an odd criticism because in fact we found that the cost of hybrid airships, new aircraft, and the balloon with hose option were broadly comparable. gas guns (which are half the price in $/kg of solid-propellant guns) We did not spend significant time on gas guns because we talked to David Whelan, US National Academy member and senior scientist at Boeing, one of the world experts on this topic, and he advised us that gas guns would not be a significant advantage for the altitude range that is relevant here. Even if gas guns were half the price of solid propellant guns as you assert, and I do not know of a study that shows that to be true when you count capital and operating costs, the cost would still be absurdly high compared to the other options investigated (hybrid airships, the balloon with hose, or regular aircraft) and therefore all but irrelevant. David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Andrew Lockley Sent: Thursday, August 30, 2012 5:52 PM To: geoengineering; David Keith Subject: [geo] Cost analysis of stratospheric albedo modification delivery systems (ERL) Open Access Poster's note: Isn't this just a reformatted version of the Aurora flight report? If so, it ignores gas guns (which are half the price in $/kg of solid-propellant guns) and contradicts SPICE balloon cost estimates. It works up aircraft way more than other tech, leading to unsurprisingly lower cost estimates of these technologies. Coming up with low prices for worked up tech seems a common thread in papers. This could be clarified by authors generally, I feel. http://iopscience.iop.org/1748-9326/7/3/034019 We perform engineering cost analyses of systems capable of delivering 1-5 million metric tonnes (Mt) of albedo modification material to altitudes of 18-30 km. The goal is to compare a range of delivery systems evaluated on a consistent cost basis. Cost estimates are developed with statistical cost estimating relationships based on historical costs of aerospace development programs and operations concepts using labor rates appropriate to the operations. We evaluate existing aircraft cost of acquisition and operations, perform in-depth new aircraft and airship design studies and cost analyses, and survey rockets, guns, and suspended gas and slurry pipes, comparing their costs to those of aircraft and airships. Annual costs for delivery systems based on new aircraft designs are estimated to be $1-3B to deliver 1 Mt to 20-30 km or $2-8B to deliver 5 Mt to the same altitude range. Costs for hybrid airships may be competitive, but their large surface area complicates operations in high altitude wind shear, and development costs are more uncertain than those for airplanes. Pipes suspended by floating platforms provide low recurring costs to pump a liquid or gas to altitudes as high as ~ 20 km, but the research, development, testing and evaluation costs of these systems are high and carry a large uncertainty; the pipe system's high operating pressures and tensile strength
RE: [geo] Cost analysis of stratospheric albedo modification delivery systems (ERL) Open Access
Andrew Our job was not to make an economic case [for or] against these technologies, it was just to do transparent evenhanded analysis. On this topic I just don't have a bias about what the answer is. There are lots of weaknesses in the our study, but I think one of its strengths was that it used a relatively evenhanded treatment as none of the people involved has a particular attachment to or professional involvement in on any outcome. (I suppose you might argue that Aurora has primarily done aircraft, but Aurora now does contract engineering on a wide range of aerospace systems and I do not believe that strongly influence the outcome here. We are working on balloon systems with suspended tethers as part of our development of possible experiments). I think there are lots of very fine contributions in the work coming out of the SPICE group, but I do not think it is unfair to point out that this group is focused on developing a particular technology. In any case, the big answer from this paper and several others are that costs of delivery are small enough that they don't matter in any sensible policy analysis. The goal of our paper was help establish that fact as well as to establish that delivery could be accomplished with technologies that could be procured from multiple vendors today. It is fun to get into playing around with some particular technology to one loves to try and see if you can do the job a little bit cheaper. I have yet to see a coherent quantitative argument why it matters to get costs under the roughly few $/kg level we found here. I would be happy to see a high quality analysis of a novel gun the system that showed that costs were substantially cheaper. But what is needed here is analysis not assertions. Saying that the Novim study notes the opportunity for substantial costs savings does not say much. As a contributor on the Novim study, I can tell you we spent far less time analyzing the gun system there and we did in the work Aurora. David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Andrew Lockley Sent: Wednesday, September 05, 2012 9:30 AM To: David Keith Cc: geoengineering Subject: Re: [geo] Cost analysis of stratospheric albedo modification delivery systems (ERL) Open Access David Thanks for your reply. For the avoidance of doubt, I was grouping airships and fixed-wing craft as 'aircraft'. I don't doubt that your work in this area was very valuable. My concern is in the comparison of worked-up technology with less well developed technology. For comparison, you can consider the recent Phil Trans A paper by the SPICE team, which considers similar issues. This paper engineers the balloon system preferentially, and thus considers this to be a superior technology due to the cost improvements from this engineering process. The tendency should be clear, but to state explicitly: better worked technologies tend to have better cost profiles. (Paper at http://rsta.royalsocietypublishing.org/content/370/1974/4263.full.pdf ) My fear is that the analysis in your paper suffers this problem particularly as regards gun technology. You consider (briefly) hydrogen guns - but these are not necessary for the altitudes you try to reach. Methane-air or Methane-oxygen is adequate. These do not appear to have been discussed at all. Hydrogen guns do indeed have significant advantages for high altitude or widely-dispersed payloads, as their muzzle velocity is so high. But methane propellant is comparable to the Mk7 charge in terms of performance, and is vastly cheaper. N.B. I've spoken to industry experts too when developing my arguments - most notably Utron. The other major cost in the gun system is the projectile. Blackstock notes the opportunity for substantial costs savings (due to mass production) in the Novim report, and there are additional possibilities for cost-cutting by recovery, such as parachute recovery, splashdown, etc., which can potentially reduce the costs of projectiles by an order of magnitude or more if reuse is practical. Furthermore, guns generally offer substantial performance advantages in terms of their ability to deal with high-altitude dispersal and distribution through problematic weather conditions - something which may severely affect airships particularly. In summary, therefore: the paper is great at bringing forward proposals for optimised aircraft (inc. airships). However, it does not satisfactorily consider other technologies (e.g. guns), and therefore should not be used to make an economic case against these technologies. Thanks A On 5 September 2012 13:56, David Keith david_ke...@harvard.edu wrote: Andrew Answers to your questions about the our recent URL paper on stratospheric albedo modification delivery systems. Q: Isn't this just a reformatted version of the Aurora flight report? A: Essentially yes
RE: [geo] David Keith New Mexico experiment, press reaction
Despite the quotes Martin Lukacs the reporter for the Guardian did not talk to either Jim Anderson or me in reporting this story. The story is incorrect in several crucial ways. First and most important no experiment is definitely planed or funded. It's true that we are in the early stages of planning and experiment to look at aerosol and ozone science questions, and that one of the topics we will address is risks of aerosol SRM. A balloon based platform is one of the possible methods. But, there is no possibility that it will go forward within a year as claimed in the article. Moreover, I would only support and participate in such an experiment if (a) it's funding was substantially public and (b) it was supported and approved by relevant public science research agencies, and (c) it provided a real opportunity to advance our understanding of the risk or efficacy of SRM. While this story appears in a reputable paper has the appearance of primary reporting, it seems to have been assembled from fragments found on the web without even the most basic fact-checking. David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Andrew Lockley Sent: Tuesday, July 17, 2012 12:01 PM To: geoengineering@googlegroups.com Subject: [geo] David Keith New Mexico experiment, press reaction http://m.guardian.co.uk/environment/2012/jul/17/us-geoengineers-spray-sun-balloon?cat=environmenttype=article US geoengineers to spray sun-reflecting chemicals from balloon Experiment in New Mexico will try to establish the possibility of cooling the planet by dispersing sulphate aerosols Martin Lukacs guardian.co.ukhttp://guardian.co.uk, Tuesday 17 July 2012 The field experiment in solar geoengineering aims to ultimately create a technology to replicate the observed effects of volcanoes that spew sulphates into the stratosphere. Two Harvard engineers are to spray sun-reflecting chemical particles into the atmosphere to artificially cool the planet, using a balloon flying 80,000 feet over Fort Sumner, New Mexico. The field experiment in solar geoengineering aims to ultimately create a technology to replicate the observed effects of volcanoes that spew sulphates into the stratosphere, using sulphate aerosols to bounce sunlight back to space and decrease the temperature of the Earth. David Keith, one of the investigators, has argued that solar geoengineering could be an inexpensive method to slow down global warming, but other scientists warn that it could have unpredictable, disastrous consequences for the Earth's weather systems and food supplies. Environmental groups fear that the push to make geoengineering a plan B for climate change will undermine efforts to reduce carbon emissions. Keith, who manages a multimillion dollar geoengineering research fund provided by Microsoft founder Bill Gates, previously commissioned a study by a US aerospace company that made the case for the feasibility of large-scale deployment of solar geoengineering technologies. His US experiment, conducted with American James Anderson, will take place within a year and involve the release of tens or hundreds of kilograms of particles to measure the impacts on ozone chemistry, and to test ways to make sulphate aerosols the appropriate size. Since it is impossible to simulate the complexity of the stratosphere in a laboratory, Keith says the experiment will provide an opportunity to improve models of how the ozone layer could be altered by much larger-scale sulphate spraying. The objective is not to alter the climate, but simply to probe the processes at a micro scale, said Keith. The direct risk is very small. While the experiment may not harm the climate, environmental groups say that the global environmental risks of solar geoengineering have been amply identified through modelling and the study of the impacts of sulphuric dust emitted by volcanoes. Impacts include the potential for further damage to the ozone layer, and disruption of rainfall, particularly in tropical and subtropical regions - potentially threatening the food supplies of billions of people, said Pat Mooney, executive director of the Canadian-based technology watchdog ETC Group. It will do nothing to decrease levels of greenhouse gases in the atmosphere or halt ocean acidification. And solar geoengineering is likely to increase the risk of climate-related international conflict - given that the modelling to date shows it poses greater risks to the global south. A scientific study published last month concluded that solar radiation management could decrease rainfall by 15% in areas of North America and northern Eurasia and by more than 20% in central South America. Last autumn, a British field test of a balloon-and-hosepipe device that would have pumped water into the sky generated controversy. The government-funded project - Stratospheric Particle Injection for Climate Engineering (Spice
RE: [geo] David Keith New Mexico experiment, press reaction
Folks My error. Looking through my records I find that I did talk with Martin Lukacs when he called reporting a story for the Toronto Star. The story is erroneous in the ways I described below, but I was in error in saying that I never talked to Lukacs. David From: David Keith Sent: Tuesday, July 17, 2012 12:18 PM To: 'andrew.lock...@gmail.com'; geoengineering@googlegroups.com Subject: RE: [geo] David Keith New Mexico experiment, press reaction Despite the quotes Martin Lukacs the reporter for the Guardian did not talk to either Jim Anderson or me in reporting this story. The story is incorrect in several crucial ways. First and most important no experiment is definitely planed or funded. It's true that we are in the early stages of planning and experiment to look at aerosol and ozone science questions, and that one of the topics we will address is risks of aerosol SRM. A balloon based platform is one of the possible methods. But, there is no possibility that it will go forward within a year as claimed in the article. Moreover, I would only support and participate in such an experiment if (a) it's funding was substantially public and (b) it was supported and approved by relevant public science research agencies, and (c) it provided a real opportunity to advance our understanding of the risk or efficacy of SRM. While this story appears in a reputable paper has the appearance of primary reporting, it seems to have been assembled from fragments found on the web without even the most basic fact-checking. David From: geoengineering@googlegroups.commailto:geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com]mailto:[mailto:geoengineering@googlegroups.com] On Behalf Of Andrew Lockley Sent: Tuesday, July 17, 2012 12:01 PM To: geoengineering@googlegroups.commailto:geoengineering@googlegroups.com Subject: [geo] David Keith New Mexico experiment, press reaction http://m.guardian.co.uk/environment/2012/jul/17/us-geoengineers-spray-sun-balloon?cat=environmenttype=article US geoengineers to spray sun-reflecting chemicals from balloon Experiment in New Mexico will try to establish the possibility of cooling the planet by dispersing sulphate aerosols Martin Lukacs guardian.co.ukhttp://guardian.co.uk, Tuesday 17 July 2012 The field experiment in solar geoengineering aims to ultimately create a technology to replicate the observed effects of volcanoes that spew sulphates into the stratosphere. Two Harvard engineers are to spray sun-reflecting chemical particles into the atmosphere to artificially cool the planet, using a balloon flying 80,000 feet over Fort Sumner, New Mexico. The field experiment in solar geoengineering aims to ultimately create a technology to replicate the observed effects of volcanoes that spew sulphates into the stratosphere, using sulphate aerosols to bounce sunlight back to space and decrease the temperature of the Earth. David Keith, one of the investigators, has argued that solar geoengineering could be an inexpensive method to slow down global warming, but other scientists warn that it could have unpredictable, disastrous consequences for the Earth's weather systems and food supplies. Environmental groups fear that the push to make geoengineering a plan B for climate change will undermine efforts to reduce carbon emissions. Keith, who manages a multimillion dollar geoengineering research fund provided by Microsoft founder Bill Gates, previously commissioned a study by a US aerospace company that made the case for the feasibility of large-scale deployment of solar geoengineering technologies. His US experiment, conducted with American James Anderson, will take place within a year and involve the release of tens or hundreds of kilograms of particles to measure the impacts on ozone chemistry, and to test ways to make sulphate aerosols the appropriate size. Since it is impossible to simulate the complexity of the stratosphere in a laboratory, Keith says the experiment will provide an opportunity to improve models of how the ozone layer could be altered by much larger-scale sulphate spraying. The objective is not to alter the climate, but simply to probe the processes at a micro scale, said Keith. The direct risk is very small. While the experiment may not harm the climate, environmental groups say that the global environmental risks of solar geoengineering have been amply identified through modelling and the study of the impacts of sulphuric dust emitted by volcanoes. Impacts include the potential for further damage to the ozone layer, and disruption of rainfall, particularly in tropical and subtropical regions - potentially threatening the food supplies of billions of people, said Pat Mooney, executive director of the Canadian-based technology watchdog ETC Group. It will do nothing to decrease levels of greenhouse gases in the atmosphere or halt ocean acidification. And solar geoengineering is likely
[geo] New paper: Juan B Moreno-Cruz and David W Keith Climate Policy under Uncertainty: A Case for Geoengineering
Juan B Moreno-Cruz and David W Keith. (2012). Climate Policy under Uncertainty: A Case for Geoengineering. Climatic Change, DOI 10.1007/s10584-012-0487-4. Available at http://www.springerlink.com/content/l824m4unw0472803/fulltext.pdf N.B., Almost all my papers are available at http://www.keith.seas.harvard.edu/geo.html. Some need a password, but all you have to do to get it is to send email to Hollie Roberts at rober...@ucalgary.camailto:rober...@ucalgary.ca. I also put a bunch of video's up on the site including this interview on HardTalk on of the BBC's leading interview programs: http://www.youtube.com/watch?v=dJTpZgubtPkfeature=youtu.be. See also: http://blogs.nature.com/from_the_lab_bench/2012/06/24/the-gatekeepers-of-sunlight Juan B Moreno-Cruz and David W Keith, Abstract: Abstract Solar Radiation Management (SRM) has two characteristics that make it useful for managing climate risk: it is quick and it is cheap. SRM cannot, however, perfectly offset CO2-driven climate change, and its use introduces novel climate and environmental risks. We introduce SRM in a simple economic model of climate change that is designed to explore the interaction between uncertainty in the climate's response to CO2 and the risks of SRM in the face of carbon-cycle inertia. The fact that SRM can be implemented quickly, reducing the effects of inertia, makes it a valuable tool to manage climate risks even if it is relatively ineffective at compensating for CO2-driven climate change or if its costs are large compared to traditional abatement strategies. Uncertainty about SRM is high, and decision makers must decide whether or not to commit to research that might reduce this uncertainty. We find that even modest reductions in uncertainty about the side effects of SRM can reduce the overall costs of climate change in the order of 10%. -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] Mixing of sulphur precursor gases + Response to Simone
Andrew Dipping into this list after a long time ignoring it. You asked: One thing which I personally am currently unclear on is the optimal microscale mixing ratios required. Has anyone considered the effect of a dense injection regime, e.g. a balloon or slurry pipe, versus a distributed regime, e.g. an aircraft fleet? Simone Tilmes said I think it is important to point out that there is very likely a limit on how much the Earth's surface could be cooled using sulfate aerosols, due to coagulation processes and fall out of aerosols. Only less than 2 W/m2 reduction of global net surface SW flux was achieved in the study by Heckendorn et al., 2009, using a micro-physical model to consider size distributions of the aerosols. Niemeier et al., 2010, achieved a stronger forcing if injecting particles at 30hPa, which allow them to stay longer in the stratosphere. Though it will be hard to inject particles that high. Small scale mixing is exactly what we focused on in: Jeffrey R. Pierce, Debra K. Weisenstein, Patricia Heckendorn, Thomas Peter and David W. Keith. (2010). Efficient formation of stratospheric aerosol for geoengineering by emission of condensible vapor from aircraft. Geophysical Research Letters, 37, L18805, doi:10.1029/2010GL043975. (PDF with no password needed) The point of this paper is that releasing H2SO4 vapor in plumes that are rapidly mixed allows production of sulfate aerosol with effective size distribution. We coupled a small-scale plume to a global model and found that, in our model, much less sulfate was required to get radiative forcings of a few Wm^-2 that is required with the SO2 method. (E.g., to get 4 Wm^-2 one needs about 8 Mt-S/year with this 'direct aerosol method' versus 20 with SO2.) This method would not work with balloon pipes (assuming reasonable limits on the number of pipes) because dispersal rates must be too big for the H2SO4 vapor route to work. Moreover, we also looked a various SO2 schemes and we do find that reasonably even distribution is important to avoid the big droplet problem. English, Toon and Mill's found similar results with respect to the need for broad dispersal of SO2 http://www.atmos-chem-phys.net/12/4775/2012/acp-12-4775-2012.pdf. At first glance this paper appears to contradict ours on utility of direct H2SO4 injection, but on close inspection I think it shows strong agreement. They found that H2SO4 emitted in dispersed from-that is mixed at the grid-box level-has no advantage. This is exactly what one would expect since from the aerosols microphysics is just like the production of H2SO4 by oxidation of SO2. My understanding is that subsequent e-mail exchanges between English and Pierce have clarified that there is no essential disagreement on this point. Indeed it's not clear if there's any way that one could disperse H2SO4 evenly in a way that matched the simulation of English et al. David -Original Message- From: geoengineering@googlegroups.commailto:geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com]mailto:[mailto:geoengineering@googlegroups.com] On Behalf Of Andrew Lockley Sent: Tuesday, June 05, 2012 7:18 PM To: geoengineering Subject: [geo] Mixing of sulphur precursor gases Hi This paper is well worth reading Heckendorn, P.; Weisenstein, D.; Fueglistaler, S.; Luo, B. P.; Rozanov, E.; Schraner, M.; Thomason, L. W.; Peter, T. (2009). The impact of geoengineering aerosols on stratospheric temperature and ozone. Environmental Research Letters 4: 045108. Bibcode2009ERL.4d5108H. doi:10.1088/1748-9326/4/4/045108 The authors consider the temporal and spatial injection regime best suited to attaining well-mixed sulphur particles of the correct size distribution for geoengineering use. They conclude that spatial distribution is helpful, but temporal distribution is unhelpful. I personally would welcome list discussion on whether this conclusion is seen as reliable, and additionally clarification of the processes involved. One thing which I personally am currently unclear on is the optimal microscale mixing ratios required. Has anyone considered the effect of a dense injection regime, e.g. a balloon or slurry pipe, versus a distributed regime, e.g. an aircraft fleet? Heckendorn do not seem to have addressed this issue at all in their paper. It's unclear to me whether the injection density on a scale of 10E1-10E4m would be significant in the formation of aerosols. I'm not aware of any paper which considers this microscale mixing. Any links comments are appreciated. A -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.commailto:geoengineering@googlegroups.com. To unsubscribe from this group, send email to
RE: [geo] Regional SRM experiment
Folks I am not getting this, and yet I am close to it. My office is down the hall from the GEOS-Chem group that produced these papers. We collaborate in that Debra Weisenstein works with me and with that group is doing modeling for geoengineering and looking into improvements to the GEOS-Chem stratospheric chemistry. 1. Can someone tell me exactly what would be tested here? Climate response? Aerosol radiative forcing? 2. Is there a sensible reason why you one would prefer troposphere SO2 for geoengineering if one wanted to do it? Recall that trop SO2 now is linked to about 1 million air pollution deaths per year globally as well as acid rain etc. 3. The idea that cutting tropospheric SO2 pollution is a form of geoengineering would seem to me to extend the definition of geoengineering to mean, in effect, any human action that may alter the climate. I doubt this definition will help clarify debate. Yours, David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Hawkins, Dave Sent: Tuesday, May 01, 2012 10:51 AM To: natcurr...@gmail.com; geoengineering@googlegroups.com Cc: mmacc...@comcast.net Subject: RE: [geo] Regional SRM experiment Nathan, The CEC report you link to was useful but is now dated. Much more current information on SO2 emissions (up to and including 4th quarter 2011 for the power sector) is available thanks to the 1990 Clean Air Act, which required SO2 continuous emission monitors on all coal power plants in the 48 contiguous states of the US. A handy spreadsheet of national SO2 emission trends from 1980 to 2010 can be found here: http://www.epa.gov/airmarkets/progress/ARPCAIR_downloads/CAIR_ARP_2010_data_1.xls This spreadsheet also includes data disaggregated by state and by month. Other pages at the airmarkets link above will get you access to hourly emissions and operational data from all significant US coal power plants. (FWIW, getting the rules in place to require these data to be reported at all, much less to be reported electronically and accessible to anyone, required quite a lot of persistent advocacy.) The national SO2 trends are informative as to the scale of the reductions from more than 17 million tons of SO2 from the power sector in 1980 to about 5.2 million tons in 2010. The combination of EPA's new transport rule and toxics rule will cut the load further to about 2 million tons in the 2015-2016 time frame. http://www.epa.gov/ttn/ecas/regdata/RIAs/matsriafinal.pdf, Table 3-4. But the additional instrumentation I was referring to in my email was not emission monitoring data (as the above information indicates, we now have that pretty well in place in the US for the power sector). Rather, I am thinking of high resolution data of the characteristics of the atmosphere that might change as these additional emission reduction occur. I don't know enough to have anything in particular in mind but I imagine there are some on this list who could identify the data sets they would like to have to fully characterize the forcing and other aspects of the changes brought about by the large SO2 reductions from 1980 to date and from the large additional percentage reductions that will occur over the next 3-5 years. For example, how linear or nonlinear are the forcing responses to a given tonnage reduction in fine particle precursors or a given ppm change in fine particle concentrations. My hunch is that the localized impacts will differ depending on the baseline atmospheric conditions on which the emission changes are imposed. Knowing more about that might be nice to help improve modeling estimates of the local/regional impacts of SRM experiments. David From: geoengineering@googlegroups.commailto:geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Nathan Currier Sent: Tuesday, May 01, 2012 11:38 AM To: geoengineering@googlegroups.commailto:geoengineering@googlegroups.com Cc: mmacc...@comcast.netmailto:mmacc...@comcast.net; Geoengineering Subject: Re: [geo] Regional SRM experiment Hi, David - I fully agree with that, and actually used that same MIT paper in something I wrote up for the group AMEG recently. In fact, if you look at table 3.3 in this - http://www.findthatfile.com/search-19564999-hPDF/download-documents-4876_powerplant_airemission_en.pdf.htm you'll also see that of the top 10 highest SO2-producing power plants in the US - and these are the only US plants that put out over 100,000 mt SO2/yr each (and their inputs get smaller pretty quickly as the sizes decrease) - 7 of the 10 are just in Penn OH alone. On the dot map of US SO2 emissions in the attached, these two states are almost invisible, being swallowed up by a big dot for all the SO2 there. I don't have a figure for the average loading of the two states, but it could be roughly ascertained pretty easily by EPA's SO2 trends map. Anyhow, just a study of the SO2 in these two
RE: [geo] Good popsci article on key SRM facilitator tech
Agreed with John here. Why was this posted at all? Given (a) that conventional aircraft engines can get sulfate and other aerosols to altitudes above 20 km, and that (b) both models and basic understanding of stratospheric circulation suggests this is a sufficient altitude. This list would be more useful if the posts had a higher signal-to-noise ratio. David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of John Latham Sent: Friday, April 27, 2012 9:09 AM To: s.sal...@ed.ac.uk; geoengineering@googlegroups.com Subject: RE: [geo] Good popsci article on key SRM facilitator tech Hello Andrew, Not sure if this is the same point as that made by Steve below. Please dont call stratospheric sulphur seeding SRM. The implicit message conveyed by doing so is that there is only one SRM scheme whereas in fact there are several. Sulphur seeding is the best recognised and best supported SRM idea. It can easily handle having a few neighbours. You are of course not the only one who doesnt make this distiction. All Best Wishes, John. John Latham Address: P.O. Box 3000,MMM,NCAR,Boulder,CO 80307-3000 Email: lat...@ucar.edu or john.latha...@manchester.ac.uk Tel: (US-Work) 303-497-8182 or (US-Home) 303-444-2429 or (US-Cell) 303-882-0724 or (UK) 01928-730-002 http://www.mmm.ucar.edu/people/latham From: geoengineering@googlegroups.com [geoengineering@googlegroups.com] on behalf of Stephen Salter [s.sal...@ed.ac.uk] Sent: Friday, April 27, 2012 3:40 PM To: geoengineering@googlegroups.com Subject: Re: [geo] Good popsci article on key SRM facilitator tech Andrew May I suggest the insertion of the word 'stratospheric' before SRM in your last email. Stephen Emeritus Professor of Engineering Design Institute for Energy Systems School of Engineering Mayfield Road University of Edinburgh EH9 3JL Scotland Tel +44 131 650 5704 Mobile 07795 203 195 www.see.ed.ac.uk/~shs On 27/04/2012 15:27, Andrew Lockley wrote: Mech eng fans will be interested in this great article on high altitude engines, which have potential for application to the heavy, high altitude lift needed for SRM. Please view online to access rich media. http://www.bbc.co.uk/news/science-environment-17864782 A More from Jonathan Follow Jonathan on Twitter Key tests for Skylonspaceplane project COMMENTS (215) The pre-cooler demonstration is a major step in proving the Skylon concept UK engineers have begun critical tests on a new engine technology designed to lift a spaceplane into orbit. The proposed Skylon vehicle would operate like an airliner, taking off and landing at a conventional runway. Its major innovation is the Sabre engine, which can breathe air like a jet at lower speeds but switch to a rocket mode in the high atmosphere. Reaction Engines Limited (REL) believes the test campaign will prove the readiness of Sabre's key elements. This being so, the firm would then approach investors to raise the £250m needed to take the project into the final design phase. We intend to go to the Farnborough International Air Show in July with a clear message, explained REL managing director Alan Bond. The message is that Britain has the next step beyond the jet engine; that we can reduce the world to four hours - the maximum time it would take to go anywhere. And that it also gives us aircraft that can go into space, replacing all the expendable rockets we use today. To have a chance of delivering this message, REL's engineers will need a flawless performance in the experiments now being run on a rig at their headquarters in Culham, Oxfordshire. The test stand will not validate the full Sabre propulsion system, but simply its enabling technology - a special type of pre-cooler heat exchanger. Sabre is part jet engine, part rocket engine. It burns hydrogen and oxygen to provide thrust - but in the lower atmosphere this oxygen is taken from the atmosphere. The approach should save weight and allow Skylon to go straight to orbit without the need for the multiple propellant stages seen in today's throw-away rockets. But it is a challenging prospect. At high speeds, the Sabre engines must cope with 1,000-degree gases entering their intakes. These need to be cooled prior to being compressed and burnt with the hydrogen. Reaction Engines' breakthrough is a module containing arrays of extremely fine piping that can extract the heat and plunge the intake gases to minus 140C in just 1/100th of a second. Ordinarily, the moisture in the air would be expected to freeze out rapidly, covering the pre-cooler's pipes in a blanket of frost and compromising their operation. But the REL team has also devised a means to stop this happening, permitting Sabre to run in jet mode for as long as is needed before making the transition to a booster rocket. Sabre
[geo] RE: Rough sketch of a small-scale tropospheric aerosol program
Folks Part of this thread is spinning into an exercise in drafting a statement. I suggest that this activity move off-line to a smaller group. A few specific comments: 1. “we have a method that does not use sulphur”. Maybe. As a method of SRM, sea salt aerosols offer many potential advantages and some serious disadvantages. For this reason I strongly support research including active field research. But, there are still **very** large uncertainties and it is entirely possible that the method will prove to have very limited applicability. Over hype of high-leverage technologies is a recipe for disaster. 2. Stratospheric sulfates are plausible because (a) we know how to deliver sulfate at low cost with current technologies and (b) the experience with volcanic emissions gives us some confidence that we understand some of the key chemistry and physics. There will still be unexpected outcomes. Here is a specific example. I you wanted to increase the radiative forcing using strat sulfate aerosols at a rate sufficient to roughly offset the growth of anthropogenic radiative forcing you would need ramp up the sulfate addition rate at about 1/3 of a Mt-S per decade. That is if you started at zero you would need about 1/3 of a Mt-S per year after a decade and 2/3 after two decades. (This assumes 0.25 Wm^-2/decade forcing ramp and 0.7 Wm^-2 for 1 Mt-S/year see; Pierce et al, http://www.keith.seas.harvard.edu/preprints/127.Pierce.EfficientFormStratsAerosol.p.pdf) Sulfate aerosols in the stratosphere are promising. I would not support deployment without a much broader effort on both science and governance, but with luck, I think this could be accomplished reasonably quickly. There are lots of other options that offer similar promise. We are spending considerable effort thinking about how to increase the effectiveness and understand the risks of sulfate and other aerosols. 3. Tropospheric sulfates require much large injection rates to achieve the same radiative forcing. Do the math on health impacts using paper I cited a few posts back. It’s not promising. I would respectfully suggest that one be cautious about propose something that will have health consequences that large without a **very** clear rational for why you are doing it. David From: Tenney Naumer [mailto:alais.el...@gmail.com] Sent: Wednesday, March 21, 2012 8:06 PM To: Mike MacCracken Cc: P. Wadhams; Nathan Currier; Geoengineering; Andrew Lockley; john.latha...@manchester.ac.uk; Govindasamy Bala; Veli Albert Kallio; David Keith; v.ga...@open.ac.uk; John Nissen; Peter R Carter; Gary Houser; Anthony Cook; Graham Innes; PaulHenry Beckwith; Brian Orr; JON HUGHES; Nick Breeze Subject: Re: Rough sketch of a small-scale tropospheric aerosol program Dear Mike, I think the point is that we have a method that does not use sulphur. The fact that many people are exposed to atmospheric sulphur now is no logical justification for its use in geoengineering. We need cleaner air in general. World governments need to invest in methods for drawing down CO2 and rid the air of other man-caused aerosols. Why exacerbate a problem that we will have to work extra hard to clean up later? Best regards, Tenney Tenney Naumer Climate Change: The Next Generationhttp://climatechangepsychology.blogspot.com Tel.: (618) 967-6453 (cell) skype: tenneynaumer On Wed, Mar 21, 2012 at 3:45 PM, Mike MacCracken mmacc...@comcast.netmailto:mmacc...@comcast.net wrote: Peter and Tenney-- I think your proposed proscription of sulfur is too harsh a restriction. As far as people are concerned, the problems have come with high concentrations and lots of other toxins mixed with them from fossil fuel power plants. As far as ecological impacts are concerned, aside from there being agricultural areas that are sulfur deficient and farmers add sulfur, the problems arise in certain types of situations (like accumulated deposition onto the snow fields of Scandinavia and then rapid melting; downwind of major industrialized areas; etc). In any case, as well, we will continue to have volcanic injections so sulfur won't be going away. On low sulfur fuel, that is mandated to happen over next several years, mainly because of problematic emissions and concentrations in port areas. This is likely, however, to have much larger scale implications as the diesel fuel is cleaned up. CCN approach and cloud whitening is great to try, but is mainly effective in clean areas where there is marine stratus and and a bit hard to do in other areas where that is not the case. Thinking that one is going to find an approach that has no side effects of any kind is, in my view, wishing for the impossible. It is, as I posed in an earlier email, like insisting on a cure for HIV/AIDS rather than accepting drugs that are able to hold off worsening of the disease while one searches for better approaches. Mike MacCracken On 3/21/12 1:59 PM, P. Wadhams p...@cam.ac.ukmailto:p
RE: [geo] Source on SRM causing warming
And... this 2-4 month lifetime is very altitude and latitude dependent. We can run some sims with the AER 2D an look but my guess from what we have done is that you could make choices that would push this up a bit. David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Alan Robock Sent: Monday, March 19, 2012 10:03 AM To: mmacc...@comcast.net Cc: Stephen Salter; Ken Caldeira; Andrew Lockley; Geoengineering; j.e.kristjans...@geo.uio.no Subject: Re: [geo] Source on SRM causing warming Dear Mike, I don't know how you do this 6 to 1 calculation. We found that the e-folding time for stratospheric aerosols in the Arctic s 2-4 months, with 4 months in the summer, the relevant time. (see http://climate.envsci.rutgers.edu/pdf/2008JD010050small.pdf ) If we compare this to the lifetime of tropospheric aerosols, on week, and add a week to the 4 months for their tropospheric time, the ratio is 130 days to 7 days, which is 19 to 1, not 6 to 1. Furthermore, the health effects of additional tropospheric pollution are not acceptable, in my opinion. Alan [On sabbatical for current academic year. The best way to contact me is by email, rob...@envsci.rutgers.edumailto:rob...@envsci.rutgers.edu, or at 732-881-1610 (cell).] Alan Robock, Professor II (Distinguished Professor) Editor, Reviews of Geophysics Director, Meteorology Undergraduate Program Associate Director, Center for Environmental Prediction Department of Environmental SciencesPhone: +1-732-932-9800 x6222 Rutgers University Fax: +1-732-932-8644 14 College Farm Road E-mail: rob...@envsci.rutgers.edumailto:rob...@envsci.rutgers.edu New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock On 3/18/2012 5:49 PM, Mike MacCracken wrote: Hi Stephen--My wording must have been confusing. For stratospheric injections at low latitudes, the lifetime is 1-2 years. The aerosols do move poleward and are carried into the troposphere in mid and high latitudes. This is one approach to trying to limit global climate change, and, as David Keith says, studies indicate that these cool the polar regions, though perhaps not in the stratosphere. Your cloud brightening approach is also to limit global warming. I'd also suggest that we could offset some of the global warming by sulfate aerosols out over vast ocean areas instead of sulfate's present dominance over, now, southeastern Asia, China, etc.--so keeping or modestly enhancing the present cooling offset. [And reducing cirrus may also be a viable approach.] A third approach is to cool the poles (and this might be good for regional purposes alone), but cooling also pulls heat out of lower latitudes and helps to cool them somewhat. The Caldeira-Wood shows it works conceptually (they reduced solar constant) and Robock et al. injected SO2 into stratosphere to do (but the full year injection of SO2/SO4 likely spread some to lower latitudes and the monsoons were affected). One thing Robock et al. found was that the lifetime of sulfate in the polar stratosphere is about two months, and so that means that the potential 100 to 1 advantage of stratospheric sulfate is not valid, and we're down to 6 to 1 compared to surface-based approaches such as CCN or microbubbles to cool incoming waters, sulfate or something similar over Arctic area, surface brightening by microbubbles, etc.--noting that such approaches are only needed (and effective) for the few months per year when the Sun is well up in the sky. As David Keith also says, there is a lot of research to be done to determine which approaches or alone or in different variants might work, or be effective or ineffective and have unintended consequences, much less how such an approach or set of approaches might be integrated with mitigation, adaptation, suffering, etc. Best, Mike MacCracken On 3/18/12 12:52 PM, Stephen Salter s.sal...@ed.ac.ukmailto:s.sal...@ed.ac.uk wrote: Mike I had thought that the plan was stratospheric aerosol to be released at low latitudes and would slowly migrate to the poles where is would gracefully descend. If you can be sure that it will all have gone in 10 days then my concerns vanish. But if the air cannot get through the water surface how can the aerosol it carries get there? It will form a blanket even if it is a very low one. A short life would mean that we do not have to worry about methane release. But can we do enough to cool the rest of the planet? Perhaps Jon Egil can tell us about blanket lifetime. Stephen Mike MacCracken wrote: The Robock et al simulations of an Arctic injection found that the lifetime of particles in the lower Arctic stratosphere was only two months. In that one would only need particles up during the sunlit season (say three months, for only really helps after the sea ice surface has melted
RE: [geo] Source on SRM causing warming
Keith says, studies indicate that these cool the polar regions, though perhaps not in the stratosphere. Your cloud brightening approach is also to limit global warming. I'd also suggest that we could offset some of the global warming by sulfate aerosols out over vast ocean areas instead of sulfate's present dominance over, now, southeastern Asia, China, etc.--so keeping or modestly enhancing the present cooling offset. [And reducing cirrus may also be a viable approach.] A third approach is to cool the poles (and this might be good for regional purposes alone), but cooling also pulls heat out of lower latitudes and helps to cool them somewhat. The Caldeira-Wood shows it works conceptually (they reduced solar constant) and Robock et al. injected SO2 into stratosphere to do (but the full year injection of SO2/SO4 likely spread some to lower latitudes and the monsoons were affected). One thing Robock et al. found was that the lifetime of sulfate in the polar stratosphere is about two months, and so that means that the potential 100 to 1 advantage of stratospheric sulfate is not valid, and we're down to 6 to 1 compared to surface-based approaches such as CCN or microbubbles to cool incoming waters, sulfate or something similar over Arctic area, surface brightening by microbubbles, etc.--noting that such approaches are only needed (and effective) for the few months per year when the Sun is well up in the sky. As David Keith also says, there is a lot of research to be done to determine which approaches or alone or in different variants might work, or be effective or ineffective and have unintended consequences, much less how such an approach or set of approaches might be integrated with mitigation, adaptation, suffering, etc. Best, Mike MacCracken On 3/18/12 12:52 PM, Stephen Salter s.sal...@ed.ac.uk mailto:s.sal...@ed.ac.uk wrote: Mike I had thought that the plan was stratospheric aerosol to be released at low latitudes and would slowly migrate to the poles where is would gracefully descend. If you can be sure that it will all have gone in 10 days then my concerns vanish. But if the air cannot get through the water surface how can the aerosol it carries get there? It will form a blanket even if it is a very low one. A short life would mean that we do not have to worry about methane release. But can we do enough to cool the rest of the planet? Perhaps Jon Egil can tell us about blanket lifetime. Stephen Mike MacCracken wrote: The Robock et al simulations of an Arctic injection found that the lifetime of particles in the lower Arctic stratosphere was only two months. In that one would only need particles up during the sunlit season (say three months, for only really helps after the sea ice surface has melted and the sun is high in the sky). During the relatively calm weather of Arctic summer, the lifetime of tropospheric sulfate, for exampleand quite possibly sea salt CCN--emitted above the inversion is likely 10 days or so. It is not at all clear to me that the 6 to 1 or so lifetime advantage of the lower stratosphere is really worth the effort to loft the aerosols. And on the temperature rise in the polar stratosphere, I would hope any calculation of the effects of the sulfate/dust injection only put it in during the sunlit seasonobviously, there would be no effect on solar radiation during the polar night, so, with a two month lifetime of aerosols there, it makes absolutely no sense to be lofting anything for about two thirds of the year. And so likely no effect on winter temperatures (although warming the coldest part of the polar winter stratosphere might well help to prevent an ozone hole from forming). So, I think a tropospheric brightening approach is likely the better option. Whether it can be done with just CCN or might also need sulfate seems to me worth investigating (what one needs may well be not just cloud brightening, but also clear sky aerosol loading). Best, Mike * On 3/17/12 8:41 PM, Ken Caldeira kcalde...@carnegie.stanford.edu mailto:kcalde...@carnegie.stanford.edu wrote: That is just misleading. The third attachment is a top-of-atmosphere radiation balance on the email I am responding to shows shortwave radiation. The attached figure shows the corresponding temperature field from the same simulation for the same time period. Note Arctic cooling. Also, we should not focus on individual regional blobs of color in an average of a single decade from a single simulation. The paper these figures came from is here: http://www.atmos-chem-phys.net/10/5999/2010/acp-10-5999-2010.pdf ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira YouTube: http://www.youtube.com/watch?v=a9LaYCbYCxo Climate change and the transition from coal to low-carbon electricity http://www.youtube.com/watch?v
RE: [geo] Re: We are top story on BBC environmental news
John Do you have a physically based model that backs up these about collapse and quadrupling of warming rate? If so, please let us see it. If not, please consider either retracting these claims or finding a way to make clear the level of uncertainty involved. We have a climate problem and a public relations problem. The first email I have from you in my archives is dated 2008 and suggests the complete disappearance of summer Arctic sea ice at the by 2013. This now seems highly unlikely. If the current claims about immanent collapse are also proved false (as I expect they will be) you will provide ammunition to those who argue against action. Reality is bad enough. David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of John Nissen Sent: Sunday, March 18, 2012 11:24 AM To: John Latham Cc: johnnissen2...@gmail.com; joshuahorton...@gmail.com; geoengineering; P. Wadhams; Stephen Salter; JON HUGHES; Albert Kallio Subject: Re: [geo] Re: We are top story on BBC environmental news Dear John, How I wish we had the time. We should have been doing what you suggest immediately after the crash in sea ice extent of September 2007 - a wake-up call. We have just left it far too late, and have no option but to try anything that might reduce the chance of a collapse in sea ice extent this year. If you just look at the PIOMAS graph of sea ice volume which is down 75% in three decades and compare it with the sea ice extent which is down 40%, it is obvious that the sea ice extent cannot hold out much longer while the ice continues thinning. There must be a great deal of heat going into melting the ice - and much of this heat is from the heating of open water by the sun when the sea ice retreats - i.e. from the albedo flip effect. After a collapse such that there's little sea ice left in September, there will be a spurt in Arctic warming, perhaps to double the current rate of warming. And after we have a nearly sea ice free Arctic ocean for six months, the warming could increase to triple or quadruple the current rate. Meanwhile there is the methane to contend with. There are already signs of an escalation of methane emissions from shallow seas of the continental shelf. That by itself would be cause for concern, since the sea ice retreat is allowing the seabed to warm well above the thaw point for methane hydrates. So I have three questions for you: 1. Do you seriously recommend that nobody does anything for at least three years while there is more research into geoengineering? 2. How can you say that geoengineering is doomed to failure? Do you really lack confidence in your own modelling? 3. What do I tell my wife and children if nothing is done and the worst happens? Kind regards, John --- On 18/03/2012 15:29, John Latham wrote: Hello John Nissen and All, John N says:- Just before the hearing, the committee had received an email [6] from some geoengineering experts recommending research but suggesting that development and deployment of geoengineering techniques was premature, thus undermining the AMEG position. I was one of the signatories that John alluded to. I believe that each one of us feel it shameful and dangerous that that research into promising SRM ideas has not been significantly financially supported. The major stages of the required research involve modelling, resolution of all technological questions, examination of - and international agreement on - possible adverse consequences of deployment, and the execution of (in the case of MCB, for example), of a limited area field-testing experiment. If the required funding was available now I think I think all the above goals could be achieved in 5 years, perhaps even 3. At the moment these goals are far from being achieved. An attempt to successfully deploy now any likely SRM technique would be doomed to failure. The technological questions have not been fully resolved - so it would not work - and there would be - in my opinion - an international outcry against deployment. We would be shooting ourselves in the foot, I think, if we tried to deploy now. If there was a major failure - which is likely - the response could be such as to prohibit further SRM work for a long time.We need to engage in crash programmes of research now, which means that we need immediately to obtain the required funding. [How, I dont know, I'm afraid]. All Best, John (Latham) John Latham Address: P.O. Box 3000,MMM,NCAR,Boulder,CO 80307-3000 Email: lat...@ucar.edu or john.latha...@manchester.ac.uk Tel: (US-Work) 303-497-8182 or (US-Home) 303-444-2429 or (US-Cell) 303-882-0724 or (UK) 01928-730-002 http://www.mmm.ucar.edu/people/latham From: geoengineering@googlegroups.com [geoengineering@googlegroups.com] on behalf of John Nissen [johnnissen2...@gmail.com]
RE: [geo] Source on SRM causing warming
Steven I am in favor of serious research on both strat aerosols and sea salt CCN. Your comments suggest that you already know the outcome of that research. You may of course be correct, and in many ways I hope you are. I, however, see less basis for certainty. A few facts that seem relevant: 1. All simulations of stratospheric aerosols of which I am aware do show an arctic cooling tendency and increase in sea ice extent. 2. There is little reason to doubt that 1 Wm^2 radiative global forcing could be produce by sulfate aerosols using well understood technologies. (That is not a claim about risks and side effects, just about basic capability.) 3. There are large uncertainties about the efficacy of sea salt CCN in producing radiative forcing. It will certainly work sometimes under some conditions, but we don't yet have a good quantitative understanding of extent of conditions in which it might work and therefore of the aggregate effectiveness. 4. There are advantages and disadvantages to the fact that the sea salt CCN is more patchy. Given this is seems to me hard to conclude that we know the answer yet. Yours, David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Stephen Salter Sent: Sunday, March 18, 2012 10:52 AM To: mmacc...@comcast.net Cc: Ken Caldeira; Andrew Lockley; Geoengineering; j.e.kristjans...@geo.uio.no Subject: Re: [geo] Source on SRM causing warming Mike I had thought that the plan was stratospheric aerosol to be released at low latitudes and would slowly migrate to the poles where is would gracefully descend. If you can be sure that it will all have gone in 10 days then my concerns vanish. But if the air cannot get through the water surface how can the aerosol it carries get there? It will form a blanket even if it is a very low one. A short life would mean that we do not have to worry about methane release. But can we do enough to cool the rest of the planet? Perhaps Jon Egil can tell us about blanket lifetime. Stephen Mike MacCracken wrote: The Robock et al simulations of an Arctic injection found that the lifetime of particles in the lower Arctic stratosphere was only two months. In that one would only need particles up during the sunlit season (say three months, for only really helps after the sea ice surface has melted and the sun is high in the sky). During the relatively calm weather of Arctic summer, the lifetime of tropospheric sulfate, for example‹and quite possibly sea salt CCN--emitted above the inversion is likely 10 days or so. It is not at all clear to me that the 6 to 1 or so lifetime advantage of the lower stratosphere is really worth the effort to loft the aerosols. And on the temperature rise in the polar stratosphere, I would hope any calculation of the effects of the sulfate/dust injection only put it in during the sunlit season‹obviously, there would be no effect on solar radiation during the polar night, so, with a two month lifetime of aerosols there, it makes absolutely no sense to be lofting anything for about two thirds of the year. And so likely no effect on winter temperatures (although warming the coldest part of the polar winter stratosphere might well help to prevent an ozone hole from forming). So, I think a tropospheric brightening approach is likely the better option. Whether it can be done with just CCN or might also need sulfate seems to me worth investigating (what one needs may well be not just cloud brightening, but also clear sky aerosol loading). Best, Mike * On 3/17/12 8:41 PM, Ken Caldeira kcalde...@carnegie.stanford.edu wrote: That is just misleading. The third attachment is a top-of-atmosphere radiation balance on the email I am responding to shows shortwave radiation. The attached figure shows the corresponding temperature field from the same simulation for the same time period. Note Arctic cooling. Also, we should not focus on individual regional blobs of color in an average of a single decade from a single simulation. The paper these figures came from is here: http://www.atmos-chem-phys.net/10/5999/2010/acp-10-5999-2010.pdf ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira YouTube: http://www.youtube.com/watch?v=a9LaYCbYCxo Climate change and the transition from coal to low-carbon electricity http://www.youtube.com/watch?v=a9LaYCbYCxo Crop yields in a geoengineered climate http://www.youtube.com/watch?v=-0LCXNoIu-c On Sat, Mar 17, 2012 at 1:31 PM, Andrew Lockley and...@andrewlockley.com wrote: Hi Here are some model outputs which Stephen sent me. These appear to show localized arctic warming in geoengineering simulations. This could be due to
RE: [geo] tropospheric aerosol use
Some simple math: Global sulfur emissions into troposphere are about 50 Mt-S per year and they have a direct radiative forcing of about -0.4 Wm^-2. These same sulfate aerosols kill about 1 million people per year. Of course current emissions are concentrated where people are you the ratio of mortality to radiative forcing is larger than it would be if you were focused on radiative forcing with tropospheric sulfate. But it would still be big. Intercontinental transport of sulfate kills, see: http://meetings.copernicus.org/www.cosis.net/abstracts/EGU2007/05111/EGU2007-J-05111.pdf If you want to make 1Wm^-2 of forcing with sulfate aerosol in the troposphere you might need of order 50 Mt-S per year, whereas in the stratosphere you might be able to get away with just over 1 Mt-S per year. (see #127 at http://www.keith.seas.harvard.edu/geo.html). One might do some optimization, but the case here has been clear for a long time. We said some of this twenty years ago. See in the table in the following though many numbers now look out of date or wrong: David W. Keith and Hadi Dowlatabadi (1992). A Serious Look at Geoengineering. Eos, Transactions American Geophysical Union, 73: 289-293. (PDF)http://www.keith.seas.harvard.edu/papers/09_Keith_1992_SeriousLookAtGeoeng_s.pdf David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Govindasamy Bala Sent: Thursday, March 15, 2012 9:53 PM To: natcurr...@gmail.com Cc: geoengineering Subject: Re: [geo] tropospheric aerosol use Climate changes by Budyko, on page 244, discusses why tropospheric aerosols are not as effective as stratospheric aerosols for climate modification. 1) life time is only a couple of weeks 2) Particle size becomes too big quickly and hence not effective for scattering 3) Presence of clouds make them less effective 4) absorption by aerosols of near IR shortwave could partially cancel the cooling by scattering. Bala On Thu, Mar 15, 2012 at 9:53 PM, Nathan Currier natcurr...@gmail.commailto:natcurr...@gmail.com wrote: Does anyone know of any published papers exploring the use of tropospheric aerosol use? cheers, Nathan -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.commailto:geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.commailto:geoengineering%2bunsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. -- Best wishes, --- Dr. G. Bala Associate Professor Center for Atmospheric and Oceanic Sciences Indian Institute of Science Bangalore - 560 012 India Tel: +91 80 2293 3428 +91 80 2293 2075 Fax: +91 80 2360 0865 +91 80 2293 3425 Email: gb...@caos.iisc.ernet.inmailto:gb...@caos.iisc.ernet.in bala.govhttp://bala.gov@gmail.comhttp://gmail.com Web:http://caos.iisc.ernet.in/faculty/gbala/gbala.html --- -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.commailto:geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.commailto:geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] Fwd: Better brush up on your lies
Strongly agree. My experience talking with chemtrails folks a good fraction are positive and well intentioned, and a quite small fraction are hostile. Here is a video that a group of chemtrails folks took and posted when they came to talk with me. You get a good sense of the range concerns: http://www.youtube.com/watch?v=_SFVYRZPXLs The Chemtrails believers are one extreme of a continuum. Here is some text on the topic from a short book I am writing: Critiques of geoengineering arise from diverse world views, indeed some of the strongest critical voices come from diametrically opposed ends of the political spectrum. Passions run very hot. To cite a vivid personal example, I have had one death threat that was serious enough to warrant a call to the police, and received many outraged comments by colleagues whom I respect. The most extreme critiques (and the death threat) come from people who are convinced by the chemtrails conspiracy theory which holds that the US government is deliberately spraying its citizens with toxins from aircraft. Believers claim that metals such as aluminum and barium are sprayed from commercial aircraft for purposes that are alleged to range from mass culling the human population to mind control. These views are wildly held, one sixth of respondents in a large public survey we ran in Canada, Brittan and the US believed that is was partially or completely true that The government has a secret program that uses airplanes to put harmful chemicals into the air. Our poll found that people are more likely to oppose geoengineering if they are skeptical of government authority and self-identify with right end of the political spectrum. While chemtrails believers are clearly an extreme, they are a coherent part of a continuum that includes a much larger group who believe that climate risks are being exaggerated by the environmental left as an excuse to justify further extension of state power at the expense of individual freedoms. To overstate it, this view sees geoengineering as a tool used by a technocratic, transnational, and godless elite who have concocted both the climate threat and the geoengineering response as a means to extend their power. From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Ken Caldeira Sent: Saturday, February 11, 2012 6:16 PM To: rob...@envsci.rutgers.edu Cc: geoengineering Subject: Re: [geo] Fwd: Better brush up on your lies I think it is not helpful to think of them as enemies. I see these people as victims of past government lies and, in many cases, their own mental instability. These people have been living under a government that has started secret wars, has secretly kidnapped and tortured people, and so on. They have lived under a government that has lied to them repeatedly. These people have no technical background to distinguish ordinary jet contrails from paranoiac visions of massive government conspiracies. They see jet trails becoming more numerous over the decades and are too innumerate to associate this increase with increase in jet travel. They have been taught that they cannot trust government statements, they certainly don't trust scientists, and now they are left with no source that they can trust (other than their like-minded fellow conspiracy theorists.) I prefer to see these ChemTrails folks as victims, both of past government lies and, in many cases I suspect, of some degree of mental illness. So, let's not look at them as enemies, but as people who need help. On Sat, Feb 11, 2012 at 3:22 PM, Alan Robock rob...@envsci.rutgers.edumailto:rob...@envsci.rutgers.edu wrote: For you all to get the flavor of some of our enemies. For some reason, a discussion I had with a chemtrails demonstration outside the AAAS meeting in San Diego two years ago, and which was posted to YouTube then, has reappeared on a website, and this is in reaction to that. Of course, the person who sent this did not sign it. Alan [On sabbatical for current academic year. The best way to contact me is by email, rob...@envsci.rutgers.edumailto:rob...@envsci.rutgers.edu, or at 732-881-1610tel:732-881-1610 (cell).] Alan Robock, Professor II (Distinguished Professor) Editor, Reviews of Geophysics Director, Meteorology Undergraduate Program Associate Director, Center for Environmental Prediction Department of Environmental SciencesPhone: +1-732-932-9800 x6222tel:%2B1-732-932-9800%20x6222 Rutgers University Fax: +1-732-932-8644tel:%2B1-732-932-8644 14 College Farm Road E-mail: rob...@envsci.rutgers.edumailto:rob...@envsci.rutgers.edu New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robockhttp://envsci.rutgers.edu/%7Erobock Original Message Subject: Better brush up on your lies Date: Sat, 11 Feb 2012 06:35:28 -0800 (PST) From: winsom88
RE: [geo] Re: Direct Air Capture Summit
Charlie I doubt this will happen. The correlation between costs of real hardware and what's citable is very week. I could find you academic cites for the cost of solar, nuclear or CCS that varied by an order of magnitude, but that does not mean the actual cost right now in a real location under actual economic conditions is that uncertain. The bottom line is that the academic literature is a poor place to go for industrial costs of anything (except well studied commodities). Take solar, for example, I feel like I have a good sense of costs, but that's from lots of interaction with top consultants to the business and from some presentations, e.g., form Bloomberg Energy Finance, that are not on the web. Air capture is ***much***less developed. There are a only handful of serious development efforts and they are private. I run one of them and we are spending well over $1m per year to do the engineering and costing of the processes we are working on. I don't think you will see a robust consensus on cost emerge for at least a decade. Particularly given that the way the early dialog as played out has made the situation so combative that cost information is obscured by folks loudly taking extreme positions. I hope you are still juggling. I am teaching my kids. Ciao, David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Charlie Zender Sent: Thursday, February 02, 2012 10:58 AM To: geoengineering Subject: [geo] Re: Direct Air Capture Summit This DACS conference will be a watershed event if it succeeds in significantly narrowing the consensus range of DAC cost from $10--1000 tCO2 to something, well, narrower. Should that occur, I hope the organizers will publish a conference report in a mainstream academic journal like Eos so 1. the wider community takes notice, and 2. we can cite it. Looks likely the number will appear in the Economist first, though. Charlie -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] New CO2 Sucker Could Help Clear the Air
The answer to Ken's rhetorical question is a qualified yes, if you ignore kinetics and assume you are looking only at the CO2 capture, desorption, clean-up and compression as he described then you can do it for pennies a kg of CO2 which is pennies per kWh. It's a yes because posed this way, ignoring kinetics and the capital and energy cost of the absorber this is the core of the standard engineering case for post-combustion CCS that has been analyzed endlessly for 20 years and for which there is lots of relevant commercial hardware. The qualification is around details of this particular material, but there are other solid and liquid systems that do this. For air capture it's harder because one cannot ignore the kinetics of uptake and the capital cost of the absorber structure. There is not much CO2 in the air so the contacting structure (the thing that actually gets CO2 from the air) must be very cheap. Here are some order of magnitude numbers: 1. You can't afford to move the air faster than a few m/s though the device (100 Pa= 6.1 kJ/mol-C= 13 m/s) 2. At that air flow, even if you get all the CO2 you are getting no more than of order 10 tCO2 m-2 yr-1. 3. Assume it is 10 tCO2 m-2 yr-1 and you don't want to pay more than 50 $/tCO2 for the amortized cost of the structure. Then the cost per square meter of inlet area must be less than 3 $k. (At 15% overall capital charge factor $3000 m-2 is $45 m-2 yr-1 which you then divide by the 10 tCO2 and round). This is hard. Large cooling towers are about $2000 m-2. 4. The amount of absorbing surface you need behind each square meter of inlet is depends on the kinetics of uptake, but at a mass transfer coefficient of 1 mm/sec one needs of order 500 m2 of surface area behind each 1 m2 of inlet. 5. For us a Carbon Engineering, using plastic packing it easy to meet this cost criteria as they cost 1$ per m2 of surface area. For our system packing cost is only a small fraction of contactor cost and a very small fraction of overall turn-key plant cost. 6. In order for a solid system to compete it must either have a much faster mass transfer coefficient or by roughly as cheap; and for a solid one must contrive a way to temperature or humidity cycle the whole solid structure cheaply and without significant air leaks. (Or find a way to gather the solids...). You can see some of our views about solid vs liquid systems at answer QA #8 at http://www.carbonengineering.com/wp-content/uploads/2011/04/CarbonEngineering-AirCaptureFAQ.pdf. Of course, the disadvantage of a liquid system is regeneration and management of liquid loss. The problems for solids are (a) getting fast uptake kinetics, (b) cycling given that the whole structure must be cycled either humidity swing or thermal swing, and (c) sorbent lifetime given that all the fancy solid must last for order a decade in air that contains contaminants such as particulates, trace gases and larger debris of all types. Bottom line: this looks like a real advance but without data on kinetics and long-term performance one can't judge how useful it is for air capture. In the near term we are reasonably confident that our liquid system will win for many large-scale air capture applications, but over the long run it's much harder to say what will happen. From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Ken Caldeira Sent: Wednesday, January 11, 2012 1:47 PM To: r...@llnl.gov Cc: zen...@uci.edu; geoengineering Subject: Re: [geo] New CO2 Sucker Could Help Clear the Air Note that there is an error of 10^6 in the article, as it says 1.72 nmol when the underlying article (attached) says mmol. Here is my little order-of-magnitude analysis: At 1.72 mmol per gram of material, to process 1 ton of CO2, we have would need ~13 tons of polyamine. The 1 g of material absorbs at 25 C needs to be heated to 85 C for three hours to give off the CO2, so this is a 60 C swing. Of course, one thing conventional power plants have is a lot of waste heat. Once it gives off the CO2, it gives it off into some gas, so you still need to figure out how to separate the CO2 from this gas. [Or maybe you make a high vacuum, but how cheap is that? If you didn't want to go with a vacuum, what would be the gas that you would have it desorb into, in order to make that separation step easy?] The average CO2 intensity of electricity production is about 615 gCO2/kWh. So you would need about 8 kg of material per kWh of electricity. If the real process were to take 3 hours, then you would need about 25 kg of material per kW of plant capacity (or 25,000 tons per GW). Can you take 8 kg of material (enough for 1 kWh's worth of CO2), have it absorb CO2, heat it up and let it desorb into a vacuum or a gas (and if a gas, then separate the CO2 from whatever the gas it desorbed into), and then compress and bury it underground, for not more than a few pennies per cycle?
Re: [geo] Occupy Wall Street Goes After Geoengineering
- Original Message - From: Josh Horton [mailto:joshuahorton...@gmail.com] Sent: Monday, October 31, 2011 03:20 PM To: geoengineering geoengineering@googlegroups.com Subject: [geo] Occupy Wall Street Goes After Geoengineering Hi everyone, Whatever your views, it was only a matter of time ... (John Bellamy Foster is editor of the socialist Monthly Review) http://mrzine.monthlyreview.org/2011/foster291011.html Capitalism and Environmental Catastrophe by John Bellamy Foster John Bellamy Foster and Fred Magdoff at Occupy Wall Street. Photo by Carrie Ann Naumoff This is a reconstruction from notes of a talk delivered at a teach-in on The Capitalist Crisis and the Environment organized by the Education and Empowerment Working Group, Occupy Wall Street, Zuccotti Park (Liberty Plaza), New York, October 23, 2011. It was based on a talk delivered the night before at the Brecht Forum. Fred Magdoff also spoke on both occasions. The Occupy Wall Street movement arose in response to the economic crisis of capitalism, and the way in which the costs of this were imposed on the 99 percent rather than the 1 percent. But the highest expression of the capitalist threat, as Naomi Klein has said, is its destruction of the planetary environment. So it is imperative that we critique that as well.1 I would like to start by pointing to the seriousness of our current environmental problem and then turn to the question of how this relates to capitalism. Only then will we be in a position to talk realistically about what we need to do to stave off or lessen catastrophe. How bad is the environmental crisis? You have all heard about the dangers of climate change due to the emission of carbon dioxide and other greenhouse gases into the atmosphere -- trapping more heat on earth. You are undoubtedly aware that global warming threatens the very future of the humanity, along with the existence of innumerable other species. Indeed, James Hansen, the leading climatologist in this country, has gone so far as to say this may be our last chance to save humanity.2 But climate change is only part of the overall environmental problem. Scientists, led by the Stockholm Resilience Centre, have recently indicated that we have crossed, or are near to crossing, nine planetary boundaries (defined in terms of sustaining the environmental conditions of the Holocene epoch in which civilization developed over the last 12,000 years): climate change, species extinction, the disruption of the nitrogen-phosphorus cycles, ocean acidification, ozone depletion, freshwater usage, land cover change, (less certainly) aerosol loading, and chemical use. Each of these rifts in planetary boundaries constitutes an actual or potential global ecological catastrophe. Indeed, in three cases -- climate change, species extinction, and the disruption of the nitrogen cycle -- we have already crossed planetary boundaries and are currently experiencing catastrophic effects. We are now in the period of what scientists call the sixth extinction, the greatest mass extinction in 65 million years, since the time of the dinosaurs; only this time the mass extinction arises from the actions of one particular species -- human beings. Our disruption of the nitrogen cycle is a major factor in the growth of dead zones in coastal waters. Ocean acidification is often called the evil twin of climate change, since it too arises from carbon dioxide emissions, and by negatively impacting the oceans it threatens planetary disruption on an equal (perhaps even greater) scale. The decreased availability of freshwater globally is emerging as an environmental crisis of horrendous proportions.3 All of this may seem completely overwhelming. How are we to cope with all of these global ecological crises/catastrophes, threatening us at every turn? Here it is important to grasp that all of these rifts in the planetary system derive from processes associated with our global production system, namely capitalism. If we are prepared to carry out a radical transformation of our system of production -- to move away from business as usual -- then there is still time to turn things around; though the remaining time in which to act is rapidly running out. Let's talk about climate change, remembering that this is only one part of the global environmental crisis, though certainly the most urgent at present. Climate science currently suggests that if we burn only half of the world's proven, economically accessible reserves of oil, gas, and coal, the resulting carbon emissions will almost certainly raise global temperatures by 2° C (3.6° F), bringing us to what is increasingly regarded as an irreversible tipping point -- after which it appears impossible to return to the preindustrial (Holocene) climate that nourished human civilization. At that point various irrevocable changes (such as the melting of Arctic sea ice and the ice sheets of Greenland and Antarctica, and the release of
RE: [geo] White roof snag
Greg et al There are a number of reasons why white roofs might cause heating that are well explained in the paper. Among them local suppression of convection and the correlation between where the roofs are and absorbing dust particles. The roofs we plan to whiten tend to be in places with dirty air, and so the problem of absorption is much more pronounced than if we scattered the whitening randomly over the planet. Your analogy to large-scale albedo changes is false because both the interaction with convection and the correlation with dirty air are not present in that case. I think it will take more papers to really nail this down but there's nothing impossible about this result and at a glance the paper seems sensible and serious. Http://www.stanford.edu/group/efmh/jacobson/Articles/Others/HeatIsland+WhiteRfs0911.pdf David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Rau, Greg Sent: Friday, October 28, 2011 10:40 AM To: s.sal...@ed.ac.uk; geoengineering@googlegroups.com Subject: RE: [geo] White roof snag A worldwide conversion to white roofs, they found, could actually warm the Earth slightly due a complex domino effect. Although white surfaces are cooler, the increased sunlight they reflect back into the atmosphere by can increase absorption of light by dark pollutants such as black carbon, which increases heating. So by analogy, increased snow/ice cover would actually warm the Earth slightly ? I don't think so, but please clue me in. - Greg From: geoengineering@googlegroups.com [geoengineering@googlegroups.com] On Behalf Of Stephen Salter [s.sal...@ed.ac.uk] Sent: Friday, October 28, 2011 4:22 AM To: geoengineering@googlegroups.com Subject: [geo] White roof snag Hi All See http://www.guardian.co.uk/environment/2011/oct/27/white-roofs-global-warming and Jacobson, M., Ten Hoeve, J. (2011). Effects of Urban Surfaces and White Roofs on Global and Regional Climate. Journal of Climate DOI: 10.1175/JCLI-D-11-00032.1http://dx.doi.org/10.1175/JCLI-D-11-00032.1 Stephen Emeritus Professor of Engineering Design Institute for Energy Systems School of Engineering Mayfield Road University of Edinburgh EH9 3JL Scotland Tel +44 131 650 5704 Mobile 07795 203 195 www.see.ed.ac.uk/~shshttp://www.see.ed.ac.uk/~shs -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] Home critique of Keith mercer paper
Andrew I am not a geoengineer, whatever that would mean. I am someone who has work for 20 years on a variety of climate and energy problems, including work on such basic stuff has measuring the rate of climate change. It is relevant to the work at hand that I have worked with some of the leading experts in assessing public opinion of emerging technologies, and that we used these techniques this study. ETC/Home evidently lacks anything substantive to say about why our study is incorrect and dislikes the conclusion so they cry bias. This is exactly what happens when I talk to the press and say that we cannot keep adding carbon to the atmosphere if we want a stable climate and that as a consequence they should shut down the oil industry. The oil industry representatives in Calgary cry bias arguing I have an interest in promoting climate change. Bias is always an easy claim you don't like the conclusions. ETC/Home argues that I am biased because I do commercial work on air capture and they assert that I support commercial work on SRM. In fact I oppose commercial work on SRM and would like to see such work prohibited where feasible. For example, I have advocated mechanisms to eliminate the possibility of patenting SRM technologies. The bias claim is doubly odd because if SRM was accepted as being a cheap and easy fix then there would be no market for CO2 scrubbing which is expensive. Therefore if I am biased in promoting SRM, I am biased against my self-interest. The other authors and reviewers of this paper have no obvious interest in promoting SRM and have an obvious self-interest in avoiding the damage to their careers by engaging in deliberately biased studies. We make no claims to have asked questions about SPICE. This claim by ETC is based solely on the release that was written by the PR person at ERL. As is a matter of public record (google it) I think the SPICE hose test is a serious mistake, so it is certainly not in my interest to promote it. I would like to see it canceled. If it succeeds it's only benefit of will be to make SRM cheaper which is precisely what we do not need. Any research on SRM in the atmosphere it should be focused on understanding and minimizing environmental risks. ETC/Home have an obvious bias in that they are an advocacy organization with a strong position to defend. Whatever the merits of this position, it simply their job to say whatever is necessary to discredit information that seems to point in a direction they do not like. This is a group that has talked about chemtrails on their webpage. David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Andrew Lockley Sent: Monday, October 24, 2011 4:42 PM To: geoengineering Subject: [geo] Home critique of Keith mercer paper A leading Geoengineer has today published a public opinion survey which is being reported as showing broad public support of geoengineering research. Suspicious? The reality of course is nothing so clear. The paper is authored by geoengineering advocate (and commercial geoengineer) David Keith and 2 other authors - one of whom is Keith's Doctoral student. While the press release claims as its headline that 72% of those interviewed support geoengineering research and that this has important implications for the SPICE project (trojan hose experiment) - actually: - the questions were only about SRM (not 'geoengineering') - the question actually never asked about 'research' and certainly not about experimentation or SPICE (it asked only whether scientists should 'study' SRM) - Some of the strongest opinions expressed by those interviewed were very critical of SRM but these weren't mentioned in the press release even though there was stronger support for these critical opinions than the 'headline'. - The opinions of over 200 people were excluded from the study at the discretion of 2 of the researchers on the basis that those people had read about SRM online. - When asked, 38% of those who responded to the survey identified the description of SRM given to them as biased in favour of SRM. Only about 2% thought it was biased against. Here is a report in The Guardian about the survey: http://www.guardian.co.uk/environment/2011/oct/24/geoengineering-survey-public-support? newsfeed=true -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.commailto:geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.commailto:geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from
RE: [geo] Wind and wave energies are not renewable after all
Mike Bala A few answers: First there is almost no link to geo here so we should probably take this off this list. The only (weak link) is weather control, see: http://www.atmos-chem-phys.org/10/769/2010/acp-10-769-2010.html 1. Bala said Generation of wind energy would increase the KE dissipation rate but this is not an external forcing to the climate system. And The current KE dissipation rate is about 2 watts/m^2. Over land, this translates to about 300 TW. Suppose wind farms extract 150 TW (which may be impractical), the dissipation rate over land will increase to 3 Wm^2. Don't you think the KE (or available PE) generation rate in the atmosphere would correspondingly increase? Of course these would be large regional climate changes. Answer: As the surface drag is increased the total dissipation does not change much. That is, as you increase the KE sink in some locations with wind turbines the dissipation decreases elsewhere keeping total about constant. See Figure 2 of our 2004 PNAS where we tried this. This is what one would expect because dissipation of KE must balance its creation from APE (see pexoto and ort or my encyclopedia article cited below for an overview of atmo energetics). Going a bit deeper one might think that with more to push against the APE generation rate would go up and the atmo heat engine get more efficient, Kerry Emanuel have suggested to me that this should not be true because of a maximum entropy principle that I do not fully understand. Bottom line: very likely Bala's assumption is wrong. 2. Bala said: I agree there would be local and regional climate changes but there should be no global mean warming. Right? Answer: mostly. One can see either warming or cooling depending on where the wind drag is applied. The point is that (a) climate changes due to drag are non-local, and (b) they can be large. 3. Mike asked about the Jacobsen paper that says no effect. Answer: I think this paper is just wrong. If it were true I could violate the first law by extracting power without altering KE and then using that power to increase APE generating infinite power with no input. Nice trick. There are now about 5 studies that confirm the broad results in our 2004 paper. The Jacobsen paper is an outlier. I expect a convincing critique will be published in the next few years. Yours, David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Mike MacCracken Sent: Tuesday, July 12, 2011 6:22 AM To: Govindasamy Bala; David Keith; Ken Caldeira Cc: Geoengineering Subject: Re: [geo] Wind and wave energies are not renewable after all Dear David--I was going to ask a similar question to Bala's-as this has actually been an ongoing argument in some circles of the energy community, with a scientific study by a Royal Society lead physicist in their energy analysis talking about a limit based on extracting a share of the existing atmospheric KE and Mark Jacobson at Stanford saying there is plenty of KE as it will be restored. It seems to me that the KE pulled out will be replaced-if not, the atmosphere would eventually not be moving and so a huge equator-pole temperature gradient would build up. With solar energy concentrated at the low latitudes and IR loss in excess at high latitudes, the atmosphere will be seeking balance; take some energy out and the atmosphere will try to restore it, rather like what happens when one puts a rock in a stream, maybe with a bit different flow, but I would not think significantly less KE. Right? Mike On 7/12/11 7:25 AM, Govindasamy Bala bala@gmail.com wrote: Hi David, Couple of questions. Generation of wind energy would increase the KE dissipation rate but this is not an external forcing to the climate system. I agree there would be local and regional climate changes but there should be no global mean warming. Right? The current KE dissipation rate is about 2 watts/m^2. Over land, this translates to about 300 TW. Suppose wind farms extract 150 TW (which may be impractical), the dissipation rate over land will increase to 3 Wm^2. Don't you think the KE (or available PE) generation rate in the atmosphere would correspondingly increase? Of course these would be large regional climate changes. Bala On Tue, Jul 12, 2011 at 8:37 AM, David Keith ke...@ucalgary.ca wrote: Responding to a VERY old thread on wind power: The only link to geoengineering here is that there is a possibility of manipulating wind turbine drag for weather control, see: At 10's TW scale extraction of wind does begin to be constrained by the generation of kinetic energy. I led the a joint NCAR-GFDL group that published the first paper on this topic see: David W. Keith et al, The influence of large-scale wind-power on global climate. Proceedings of the National Academy of Sciences, 101, p. 16115-16120. http://people.ucalgary.ca/~keith/papers/66.Keith.2004.WindAndClimate.e.pdf http
RE: [geo] HOME/ETC Group Targets IPCC: Data on public perception
Folks Earlier comments on this thread contained lots of speculation about what people think about SRM/geo. We recently submitted a paper that has some of the first results from a high-quality surveys of public perception. (Where for a survey, high-quality=that is big numbers, good demographic sampling, and well tested questions.) The paper is at http://people.ucalgary.ca/~keith/Preprints.html. You need a username password which you can get (quickly) from the Hollie Roberts see email link on the page (and I don't change it). Yours, David -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] Wind and wave energies are not renewable after all
Responding to a VERY old thread on wind power: The only link to geoengineering here is that there is a possibility of manipulating wind turbine drag for weather control, see: At 10's TW scale extraction of wind does begin to be constrained by the generation of kinetic energy. I led the a joint NCAR-GFDL group that published the first paper on this topic see: David W. Keith et al, The influence of large-scale wind-power on global climate. Proceedings of the National Academy of Sciences, 101, p. 16115-16120. http://people.ucalgary.ca/~keith/papers/66.Keith.2004.WindAndClimate.e.pdf See http://people.ucalgary.ca/~keith/papers/94.Kirk-Davidoff.SurfaceRoughnessJAS.p.pdf for a paper that says a bit about why it happens. The following web page gives and overview but it's now out of date: http://people.ucalgary.ca/~keith/wind.html Alvia's comment that about kinetic energy, i.e. the motion of molecules, confuses the physics. Kinetic energy is macroscopic velocity, random motion of molecules is just heat. It is true that large scale production and dissipation of kinetic energy must balance, have a look at Peixoto and Oort's the Physics of Climate or a short encyclopedia article I one wrote on atmospheric energetics: http://people.ucalgary.ca/~keith/papers/15.Keith.1996.Energetics.s.pdf Bottom lines: 1. Commonly cited estimates for global wind power potential are too large. On cannot get to 100 TW in any practical scheme I know about. 2. At even a few TW large scale climate effects will begin to be important. But, this does not say we should not make a few TW of wind, just that--like any energy technology-there are tradeoffs. David From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Nando Sent: Saturday, April 02, 2011 8:25 AM To: agask...@nc.rr.com Cc: andrew.lock...@gmail.com; geoengineering Subject: Re: [geo] Wind and wave energies are not renewable after all My reading of the article suggested that the authors of the study were principally claiming that wind has an impact on climate, so it is already being used. What wasn't clear from the article was what type of impact reducing the energy level of winds all over the globe through the prolific use of wind turbines might have. In a warming world, I understand we should expect stronger winds. On a simplistic generalized level that might not be relevant to local climate, slowing those stronger winds down might have an ameliorating effect on climate change. Hence the claim that The magnitude of the changes was comparable to the changes to the climate caused by doubling atmospheric concentrations of carbon dioxide might not be as bad as it is made to seem. As usually, I'm grasping at straws, but as a layman, that's what stood out for me. Nando On Sat, Apr 2, 2011 at 3:15 PM, Alvia Gaskill agask...@nc.rr.commailto:agask...@nc.rr.com wrote: Wind and wave energy are the result of the conversion of solar energy into kinetic energy, i.e. the motion of molecules. Once converted into kinetic energy it's a use it or lose it proposition. Extracting kinetic energy from the atmosphere or the ocean doesn't mean it won't be replaced by more energy from sunlight. Planting more trees will also intercept winds, albeit without the electricity generation. Who funded this research? The same people who want to prevent contact with alien civilizations? I note that the Royal Society was also a party to that one too. Note to Royal Society. When you actually find something under the bed I should be afraid of, wake me up. - Original Message - From: Andrew Lockleymailto:and...@andrewlockley.com To: geoengineeringmailto:geoengineering@googlegroups.com Sent: Friday, April 01, 2011 8:10 Subject: [geo] Wind and wave energies are not renewable after all Wind and wave energies are not renewable after all * 30 March 2011 by Mark Buchananhttp://www.newscientist.com/search?rbauthors=Mark+Buchanan * Magazine issue 2806http://www.newscientist.com/issue/2806. Subscribe and savehttp://www.newscientist.com/subscribe?promcode=nsarttop * For similar stories, visit the Energy and Fuelshttp://www.newscientist.com/topic/energy-fuels and Climate Changehttp://www.newscientist.com/topic/climate-change Topic Guides Editorial: The sun is our only truly renewable energy sourcehttp://www.newscientist.com/article/mg21028062.500-the-sun-is-our-only-truly-renewable-energy-source.html Build enough wind farms to replace fossil fuels and we could do as much damage to the climate as greenhouse global warming WITNESS a howling gale or an ocean storm, and it's hard to believe that humans could make a dent in the awesome natural forces that created them. Yet that is the provocative suggestion of one physicist who has done the sums. He concludes that it is a mistake to assume that energy sources like wind and waves are truly renewable. Build enough wind farms to replace fossil fuels, he
RE: [geo] Cost of Air Capture and the APS report
Of course it's not only an emergency strategy. Each group that has begun to think about it seriously has realized that. I said just this to the group in Lima an hour ago. David From: Alvia Gaskill [mailto:agask...@nc.rr.com] Sent: Tuesday, June 21, 2011 3:07 PM To: soco...@princeton.edu; rongretlar...@comcast.net Cc: geoengineering@googlegroups.com; David Keith Subject: Re: [geo] Cost of Air Capture and the APS report I leave the Lima group with a final thought. Is SRM only an emergency strategy? What are the pros and cons of a continuous ground-bass deployment of 1 W/m^2 of stratospheric aerosol negative forcing, as an overall helper on the margin and as a way of learning about larger deployment? No, it shouldn't only be considered as an emergency option, a term which has never been adequately defined anyway and tends to be used as a defense against the media and the opponents of geoengineering by those working in the field who can't or don't want to pardon the expression, take the heat. Paul Crutzen included use of stratospheric aerosols at about this level of negative forcing to replace the loss of tropospheric sulfate from pollution controls and others have made similar proposals (including me). To get to some kind of full-scale offset of AGW forcing (back to pre-industrial from today or some future date) you have to pass through 1 W/m2 anyway. Plus, a slowdown of warming now means less ice melted that we can't replace in the future (given what we know about how difficult that will be). This applies to cloud brightening as well or some other technology that could achieve the same impact. But i also note that to get to 1 W/m2 you have to get through 0.1 and 0.2 and 0.3, etc. You have to start somewhere. - Original Message - From: Robert Socolowmailto:soco...@princeton.edu To: rongretlar...@comcast.netmailto:rongretlar...@comcast.net Cc: geoengineering@googlegroups.commailto:geoengineering@googlegroups.com ; ke...@ucalgary.camailto:ke...@ucalgary.ca Sent: Tuesday, June 21, 2011 2:57 Subject: RE: [geo] Cost of Air Capture and the APS report Ron, Ken, and others: Given that the Lima meeting is in its middle day today, let me push everything aside to write answers to Ron's questions. I am speaking only for myself. 1. Yes, there is only one change, aside from formatting, in the June 1 version of the APS report. We say so on the second page of the preface. As we were issuing the unformatted version at the end of April, David Keith identified a clear mistake in our report, involving the pressure drop per meter for a specific packing material, which we had carried forward from a 2006 paper. Fortunately, one member of our committee, Marco Mazzotti, was an author of that paper. With one of his co-authors, he updated his earlier work with new information from the manufacturer of the packing, additionally found an error in his earlier analysis, followed a hunch that there was an easy fix for us by substituting one packing for another, and we buttoned this up. The new packing is cheaper, but we verified that our initial cost estimate for packing had been so conservative that the new packing actually fit the assumed price better. I am aware at this time of no outright error in our report. People may find some, and if they do I hope they will tell me about them. 2. Item a. In my view, the experts (specifically Keith, Lackner, and Eisenberger) were given adequate time to interact with us. Our project took two years. We established groundrules at the front end that there would be an arms-length relationship and (confirmed more than once) that as a matter of policy we would not learn confidential information. All three presented to us at our kick-off meeting in March 2009, reviewed a draft (along with almost 20 others) in April 2010, and communicated repeatedly with us. I had the personal goal of being sure that the key ideas in their work were understood by our committee and commented upon in our report. Nonetheless, none of the three of them is happy with the result. One comment all three would make is that they would have done the study differently. They would have asked what air capture could cost if one were to assume success in the presence of risk; our committee felt that in the absence of reviewable published data, this was an illegitimate task. We decided to include one cost estimate based on a benchmark design, resulting in a system whose cost is probably quite a lot higher than $600/tCO2, and in the process, by careful attention to methodology, the reader can learn how to think about costs. Personally, I now appreciate (and the reader will too who works through the calculation) that the most underestimated cost factor is the pressure drop as air moves through the contactor, which enters not only as a an energy cost but also through its impact on net carbon, even for largely decarbonized power. All three experts
[geo] Cost of Air Capture and the APS report
Several recent posts have referred to the American Physical Society's report on Air Capture. We posted a critique of the report and in turn the APS released an updated version that-using a post-facto kluge-addressed two of the errors that had identified. The our comments are posted on www.carbonengineering.comhttp://www.carbonengineering.com the website of our Air Capture startup company, the deep link is here: http://www.carbonengineering.com/wp-content/uploads/2011/05/CE_APS_DAC_Comments.pdf. We at Carbon Engineering are self-interested. Of course! But that cuts both ways. We have a huge incentive do to quality engineering that can be brought to market and not to waste our time on stuff that does not make sense. Speaking for myself, I have opportunities to do commercial work on both AC and on biomass with capture (BECCS). And I have access to high quality proprietary engineering and economic analysis of both. If I thought that BECCS was much cheaper than AC then I would not be working on AC. David -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: IPCC on geo-engineering Re: [geo] geo eng and new Friends of the Earth EWNI report urges very deep and rapid emission cuts
Bhaskar I don't speak for the IPCC, I am just helping organize the meeting. So are several other people on this distribution list. The following speculation not a position statement: Given that this is the IPCC, and given that it is a coordinating meeting between all three working groups, I think there's little danger that the focus will be narrow. However exactly the taxonomy is divided, I would guess we will end up with an expansive coverage of topics typically called geoengineering. Given there are three working groups, the review very likely cover science, environmental impacts, and social science issues including issues of governance, distributive justice, economics and public perception (one could probably get a decent sense of what the coverage might be in this area from looking at previous WG III reports). Yours, D -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of M V Bhaskar Sent: Tuesday, January 04, 2011 5:33 AM To: geoengineering Subject: Re: IPCC on geo-engineering Re: [geo] geo eng and new Friends of the Earth EWNI report urges very deep and rapid emission cuts Dr Keith Glad to know you are on the Organising committee for the IPCC WG meetings in Peru. IPCC website says - Current discussions that suggest geoengineering as an option to support climate mitigation efforts remain rather abstract and lack comprehensive risk assessments that take into account possible adverse impacts over short and longer time frames. Major uncertainties exist regarding the effects of these techniques on the physical climate system and on biogeochemical cycles, their possible impacts on human and natural systems, and their effectiveness and costs. In the field of Ocean Fertilization we believe that we have addressed many of the risks noted above. We have been causing controlled blooms of Diatoms on a medium scale for the past 5 years. So the costs, benefits, consequences, etc., are know. How can we put forth our views to the WG at Peru? best regards Bhaskar On Jan 3, 6:33 pm, David Keith ke...@ucalgary.ca wrote: I am on the organizing committee for the IPCC interworking group meeting on geoengineering in Peru this summer. The possibility of a special report will no doubt be discussed at some length at that meeting. My views are pretty well aligned with Ken's here. There are lots of summary reports written in more in the works, what is lacking is sufficient serious analysis of the various methods, their potential, risks and uncertainties. -D -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] Carbon sequestration workshop Sep 9-10, Heinz Center, Washington DC
Marty, Thanks for this gracious response. Sometimes, not often, I miss being back in physics. Cheers, D From: Marty Hoffert [mailto:marty.hoff...@nyu.edu] Sent: Wednesday, September 15, 2010 7:11 AM To: David Keith Cc: z...@atmos.umd.edu; geoengineering@googlegroups.com; James Rhodes Subject: Re: [geo] Carbon sequestration workshop Sep 9-10, Heinz Center, Washington DC I agree with David that whether to bury or to burn depends on details like whether you can burn the biomass AND bury its CO2, and whether you are looking at methane or coal as the alternate fuel for generating electricity. A big problem is that we have too few pilot plants measuring actual performance versus idealized limits in parameter space. This is a problem for all alternate energy sources. People get into huge arguments over these numbers and come to different conclusions about a technology's viability. I like to think we engineer/applied physics types are ethically compelled to abandon our beautiful theories in the face of ugly facts -- something our social science colleagues aren't quite as obsessed about. The reason I circulated that paper from climatic change was to stimulate quantitative discussion if it did I'm happy. Marty Hoffert Sent from my iPhone On Sep 14, 2010, at 8:42 PM, David Keith ke...@ucalgary.camailto:ke...@ucalgary.ca wrote: Andrew et al A few comments on this thread. Ning Zeng has it right, statements that burying beats burning in all (or even most) cases are not supported by the evidence. This is a case with the details and circumstances matter. If you have wet waste near the Mississippi and the alternative is combustion of the waste in a purpose-built biomass to electricity facility (which will be small, inefficient, and of high capital costs) then burial wins. If you have somewhat dry waste near a coal-fired power plant then cofiring wins. Marty said fundamentally it's better to bury them burn. Marty is smart guy. We both have the curse or blessing of physics as a background. But I have to say I am mystified how anyone can make any kind of fundamental claim that either burial or burning is better. I don't see any evidence for that claim in the paper. Stuart said: All of these arguments were answered last year when the paper came out, but apparently you did not digest them then, so I will repeat, briefly. Burning biomass for electricity or making ethanol avoids fossil fuel carbon emissions = 30% of the starting biomass carbon. Biomass is a poor fuel, better to bury it. Please read the paper. Or is there something about 31 that you don’t understand? I don't think the problem is our failure to understand that 31, nor do I think that this style of rhetoric helps settle arguments on complicated topics. In this particular case, the 30% depends on a set of assumptions, which in some cases might be true, in some cases burial is better than burning. However in other cases (many) they're not true. When you do the economic analysis in $/tC terms and finds that things that are easy breeze by matter. Example: capital costs. If you have to build a purpose built biomass facility than the capital cost will be well north of 2000 $/kWe and it may look big compared to the equivalent cost of building the infrastructure to do the burial. If, you're talking about retrofitting for cofiring then the capex looks 5X smaller. Utilization of capital also matters, biomass is a variable resource. One advantage of cofiring is that the capital is used all the time, if there's no biomass you just use the coal. Where is dedicated biomass systems must stand idle when there's not much biomass, when you calculate dollars per ton you have less utilization per unit capital and prices go up. Here's some of our papers that address these points: 47. David W. Keith and James S. Rhodes (2002). Bury, burn or both: A two-for-one deal on biomass carbon and energy. Climatic Change, 54: 375-377. This paper was invited with the paper Marty referred to because that Steve Schneider was concerned that the burial paper seem too much like advocacy, and wanted to hear another point of view. 95. James S. Rhodes and David W. Keith. (2008). Biomass with Capture: Negative Emissions Within social and Environmental Constraints. Climatic Change, 87: 321-328. A more general overview of various pathways to negative emissions. 64. Allen L. Robinson, James S. Rhodes and David W. Keith (2003). Assessment of Potential Carbon Dioxide Reductions due to Biomass-Coal Cofiring in the United States. Environmental Science and Technology, 37: 5081-5089. This paper was an attempt to quantify the potential of cofiring by doing a state-by-state match of biomass resources and coal-fired power. There are obvious limitations to this analysis, but it will least it was an attempt to go beyond gross national averages. It also contains a review of the status cofire
RE: [geo] Carbon sequestration workshop Sep 9-10, Heinz Center, Washington DC
Andrew et al A few comments on this thread. Ning Zeng has it right, statements that burying beats burning in all (or even most) cases are not supported by the evidence. This is a case with the details and circumstances matter. If you have wet waste near the Mississippi and the alternative is combustion of the waste in a purpose-built biomass to electricity facility (which will be small, inefficient, and of high capital costs) then burial wins. If you have somewhat dry waste near a coal-fired power plant then cofiring wins. Marty said fundamentally it's better to bury them burn. Marty is smart guy. We both have the curse or blessing of physics as a background. But I have to say I am mystified how anyone can make any kind of fundamental claim that either burial or burning is better. I don't see any evidence for that claim in the paper. Stuart said: All of these arguments were answered last year when the paper came out, but apparently you did not digest them then, so I will repeat, briefly. Burning biomass for electricity or making ethanol avoids fossil fuel carbon emissions = 30% of the starting biomass carbon. Biomass is a poor fuel, better to bury it. Please read the paper. Or is there something about 31 that you don't understand? I don't think the problem is our failure to understand that 31, nor do I think that this style of rhetoric helps settle arguments on complicated topics. In this particular case, the 30% depends on a set of assumptions, which in some cases might be true, in some cases burial is better than burning. However in other cases (many) they're not true. When you do the economic analysis in $/tC terms and finds that things that are easy breeze by matter. Example: capital costs. If you have to build a purpose built biomass facility than the capital cost will be well north of 2000 $/kWe and it may look big compared to the equivalent cost of building the infrastructure to do the burial. If, you're talking about retrofitting for cofiring then the capex looks 5X smaller. Utilization of capital also matters, biomass is a variable resource. One advantage of cofiring is that the capital is used all the time, if there's no biomass you just use the coal. Where is dedicated biomass systems must stand idle when there's not much biomass, when you calculate dollars per ton you have less utilization per unit capital and prices go up. Here's some of our papers that address these points: 47. David W. Keith and James S. Rhodes (2002). Bury, burn or both: A two-for-one deal on biomass carbon and energy. Climatic Change, 54: 375-377. This paper was invited with the paper Marty referred to because that Steve Schneider was concerned that the burial paper seem too much like advocacy, and wanted to hear another point of view. 95. James S. Rhodes and David W. Keith. (2008). Biomass with Capture: Negative Emissions Within social and Environmental Constraints. Climatic Change, 87: 321-328. A more general overview of various pathways to negative emissions. 64. Allen L. Robinson, James S. Rhodes and David W. Keith (2003). Assessment of Potential Carbon Dioxide Reductions due to Biomass-Coal Cofiring in the United States. Environmental Science and Technology, 37: 5081-5089. This paper was an attempt to quantify the potential of cofiring by doing a state-by-state match of biomass resources and coal-fired power. There are obvious limitations to this analysis, but it will least it was an attempt to go beyond gross national averages. It also contains a review of the status cofire technology by Allen Robinson a colleague at CMU who is a combustion expert. N.B., this paper has an error in one of the axis labels of the final figure. Jamie: if you're reading please double check that we have a corrected version up. 126. Jamie Rhodes and David Keith (2009). Biomass co-utilization with unconventional fossil fuels to advance energy security and climate policy. National Commission on Energy Policy Finally, things look different again when you consider gasification pathways to co-processing. Here the disadvantage of wet biomass is less important. This is a report we wrote more recently summarizing these options for a major Washington think tank. All of these papers are available for free download at http://people.ucalgary.ca/~keith/Other%20Energy.html. To sum up, I am not claiming that burial is foolish. It's a good idea that make sense under some circumstances. I am claiming that statements to the effect that burial is fundamentally or obviously better is advocacy not analysis. Yours, David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Ning Zeng Sent: Monday, September 13, 2010 6:40 AM To: geoengineering Subject: Re: [geo] Carbon sequestration workshop Sep 9-10, Heinz Center, Washington DC Dear Andrew and all
[geo] Several papers
policy under uncertainty. We find that the quick response allowed by SRM makes it important even if it is relatively ineffective at compensating for CO2-driven climate change or even if its costs are expected to be large compared to traditional mitigation strategies. Finally, we examine the implications of uncertainty about the effectiveness of SRM and show that the value of reducing this uncertainty can readily exceed several trillion US dollars over the next 100 years, providing a strong argument for a research program. David Keith Canada Research Chair in Energy and the Environment www.ucalgary.ca/~keithhttp://www.ucalgary.ca/~keith ke...@ucalgary.camailto:ke...@ucalgary.ca (403) 220-6154 -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] Joe Romm post and comment on attending the Asilomar meeting
Margaret, The board statement clarifies the goals of CRF. These goals seem admirable and entirely appropriate for an organization sponsoring a meeting like Asilomar. For my part, they answer the questions central I raised in my correspondence with Joe Romm. This relieves my concerns about attending the meeting. Thank you very much for this. I look forward to seeing you tomorrow. Yours, David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Margaret Leinen Sent: March 21, 2010 1:08 PM To: Ken Caldeira; geoengineering Subject: Re: [geo] Joe Romm post and comment on attending the Asilomar meeting Some have speculated to this group about my motivation and that of the Climate Response Fund in sponsoring the upcoming Asilomar International Conference on Climate Intervention Technologies. Recently the Board of Directors of the Climate Response Fund (and I am a member of the Board) posted a statement explicitly stating that we will not fund climate intervention experiments now or in the future. The statement also addresses other concerns that have been raised in blogs. The statement is located at: http://www.climateresponsefund.org/index.php?option=com_contentview=articleid=147Itemid=87 Margaret Leinen -- Margaret Leinen, PhD. Climate Response Fund 211 N. Union Street Suite 100 Alexandria, VA 22314 P 202-415-6545 F 703-842-8031 mlei...@climateresponsefund.org From: Ken Caldeira kcalde...@carnegie.stanford.edu Reply-To: Ken Caldeira kcalde...@gmail.com Date: Thu, 18 Mar 2010 12:38:58 -0700 To: geoengineering geoengineering@googlegroups.com Subject: [geo] Joe Romm post and comment on attending the Asilomar meeting http://climateprogress.org/2010/03/18/exclusive-chief-sponsor-of-landmark-clim ate-manipulation-conference-maintains-close-financial-ties-to-controversial-ge o-engineering-company/ A part that quotes me: -- *I have learned that the Asilomar geoengineering meeting is expected to play an important role in legitimizing and helping raise funds for Margaret Leinen's Climate Response Fund.* *I have not seen any statement from Margaret Leinen or her Fund saying that the Fund will not support geoengineering field tests nor have I seen a statement saying that the Fund would not directly or indirectly transfer resources to for-profit companies like Climos.* *I am not comfortable with the the idea that a meeting set up to create guidelines governing geoengineering field tests might be used to help raise funds for geoengineering field tests, without the informed consent of meeting participants. I am also concerned with possible conflicts of interest related to the profit motive.* *Guidelines governing such tests should be developed as a product of an ongoing process involving established professional societies and organizations, established major non-profit institutions, intergovernmental institutions, or others who do not have an apparent stake in specific outcomes.* *Margaret Leinen can obviate my concerns by stating clearly (1) that the Fund will not support geoengineering field tests and (2) that the Fund would not directly or indirectly transfer resources to for-profit geoengineering companies like Climos (or other for-profit companies with significant financial participation by members of Margaret Leinen's family). * *Without such statements, I cannot be confident that I am not being used without my consent for purposes of which I do not approve. Thus, I cannot attend the meeting.* --- I would like to point out that the Scientific Organizing Committee for the Asilomar meeting is a stellar collection of people whose integrity is beyond reproach. I have no issue with the Scientific Organizing Committee. I simply fear that they too are being used to advance the goals of Margaret Leinen and her Fund. I have no fundamental problem with what is expected to occur within the meeting proper. My problem lies with the apparent attempt of Margaret Leinen and her Fund to use the credibility of the attendees and organizers of this meeting to legitimize her Climate Response Fund and help raise money for poorly defined purposes. --- Best, Ken ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA kcalde...@carnegie.stanford.edu http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab +1 650 704 7212; fax: +1 650 462 5968 -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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
RE: [geo] Geoengineering society - draft letter
Institutions of this kind of work well when there are a large group of experts who share roughly similar expertise and when the group acts primarily as a value-neutral way to advance the discipline. We are not remotely close to that stage for geoengineering. If created now such a group would be primarily a lobby group, since there are widely divergent views about what should be done on this topic I see no chance that the group would be effective in speaking for a broad community. -David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Ken Caldeira Sent: December 13, 2009 5:32 PM To: andrew.lock...@gmail.com Cc: geoengineering Subject: Re: [geo] Geoengineering society - draft letter I am generally in favor of a bit of anarchy in science and technology, and see institutions often as mechanisms that stifle creativity and innovation. What is the purpose of such an institution? What need is it trying to fill? How do you prevent the primary goal of the institution becoming its own persistence and growth, regardless of how that might impact the stated goals of the institution? How do you prevent an institution from picking a few early winners and then excluding ideas that come along later (that challenge statements of institutional leaders, initial funding priorities, and assembled constituencies)? I am fine with people banding together to advance their specific goals. I am skeptical about the need for an institution that attempts to speak for everybody. On Sun, Dec 13, 2009 at 10:49 PM, Andrew Lockley andrew.lock...@gmail.com wrote: I note the UK's IMechE http://www.imeche.org/ is currently a strong supporter of geoengineering http://www.imeche.org/about/keythemes/environment/Climate+Change/Geoeng We have on several occasions suggested the creation of a 'geoengineering institute' on this list. I write today with an alternative suggestion. My proposal is that we present a letter to the IMechE, signed by prominent members of this list (especially those in the UK). In this, we would set out our plans for the institution, and ask that the IMechE, with its existing infrastructure and recognition, will operate this new geoengineering institution until such time as it is able to be 'spun off' as an organisation in its own right. My suggestion is that the letter should address the following points: 1) Setting out the principle of the organisation's existence as a part of the IMechE 2) The creation of a specific class of memberships for accredited and non-accredited geoengineers. 3) Defining the IMechE as the focal point for the study of the regulation and systematisation of geoengineering. 4) Encouraging the model to be adopted internationally, providing professional 'residence' to the geoengineering community worldwide. In my opinion, such a move is vital. For too long, this community has lacked a proper system of organisation, and I suggest that, after several non-starter attempts to get things moving, we now look to an established and sympathetic body to help systematise the discipline. I look forward to receiving comments of all colours by return. Thanks A -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com mailto:geoengineering%2bunsubscr...@googlegroups.com . 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 geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] Air Capture (re-naming the thread)
Agreed. It's a hybrid. The thermo looks good, but kinetic and mass-transfer limitations are severe. -D From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Ken Caldeira Sent: December 11, 2009 2:16 AM To: David Keith Cc: Greg Rau; geoengineering@googlegroups.com Subject: Re: [geo] Air Capture (re-naming the thread) It's hard to see how the energy cost of the ocean alkalinity scheme can get much below the cost of CaCO3 calcination . What about using power plant flue gases to dissolve carbonates? That seems to be an ocean alkalinity scheme that has energy costs well below calcination. ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA kcalde...@carnegie.stanford.edu http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab +1 650 704 7212; fax: +1 650 462 5968 On Fri, Dec 11, 2009 at 11:33 AM, David Keith ke...@ucalgary.ca wrote: Greg, To me it's just the common definition; I did not intend to say anything about relative merits. The topic was air capture and that seem enough for one article. I think the geochemical approaches that involve adding alkalinity to the oceans are worth serious work that's why I wrote the article geochemical carbon management article. I have also pushed this idea onto agendas at various research planning meetings (e.g., the NAS advanced sequestration meeting), and we have considered adapting calcination technology we develop for air capture to the CaO or MgO scheme though we are not putting serious work into it. In my view there is no way to make a simple choice between them. There are significant technical and institutional and governance challenges with adding alkalinity to the ocean. On the other hand, restoring PH could be a direct local environmental benefit. It's hard to see how the energy cost of the ocean alkalinity scheme can get much below the cost of CaCO3 calcination and the electrochemical schemes are expensive. One might argue, then, that air capture has lower theoretical energy cost (10's of kJ/mol vs 100's) but no one knows how to make the low energy AC work at low cost. Bottom line: real development work is needed on both; they should be linked where appropriate; and finally, it's far too early to pick winners. I know about the APS work, but I will reserve comments until it's out. The real test will be in a few years when serious end-to-end engineering cost estimates are made public. Yours, D -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com mailto:geoengineering%2bunsubscr...@googlegroups.com . 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 geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
[geo] Air Capture
Short answer: no, not with business-as-usual rules for permitting and siting. Even with money, it's all but impossible to develop deployable industrial hardware of the kind we are talking about here in five years. Alternative-world answer: Under wartime style system in which multiple independent technological pathways were pursued at once and if local planning and environmental permitting rules were suspended, then yes. Question: why would it ever make any sense to do this? The carbon cycle inertia is large. It is cheaper to get started by just cutting emissions using tools we already have from efficiency to carbon free electricity by wind, nuclear or coal-with-capture. Air capture is useful only after some of the easy stuff has already been done. -D From: Manu Sharma [mailto:orangeh...@gmail.com] Sent: December 10, 2009 7:54 AM To: David Keith Cc: Geoengineering Subject: Re: [geo] Prof. Klaus Lackner + air capture demo at AGU in SF Having read your overview in Science now, please disregard my second question about cost. I'd re-frame the first question as: If government funding is made available to the existing labs and new research institutions around the world, with the aim to make a concerted effort focussed on large-scale deployment, is it foreseeable to imagine air capture ready to be deployed within five years? Thanks, Manu -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
[geo] Recent meetings
Here are notes on a three recent meetings 1. Video's and slides of the October 30th MIT symposium are here: eathttp://web.mit.edu/esi/symposia/symposium-2009/symposium2009-presenta tions.html 2. There was a two day meeting at Max Planck Hamburg 25 and 26th November. See attached agenda. This meeting launched a major (~ 1m euro) multi-institution initiative on geoengineering that will focus primarily on climate modeling of SRM techniques. Among other things progress was made on the specification of standard experiments examining GCM responses to stratospheric aerosol geoengineering proposed as a CMIP-5 project by Alan Robock. 3. Finally, the on 27th November the University of Heidelberg kicked off an interdisciplinary initiative on The Global Governance of Climate Engineering. This well funded (~ 1m euro) project involves the Max Planck Institute for International Law, along with researchers from many disciplines including economics, atmospheric physicists, and human geography. There is a very brief German description following the link on the upper right of this page: http://www.marsilius-kolleg.uni-heidelberg.de/index_en.html http://www.marsilius-kolleg.uni-heidelberg.de/index_en.html -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. Agenda-Geoengineering-HSt-181109.pdf Description: Agenda-Geoengineering-HSt-181109.pdf
RE: [geo] What if Earth had rings like Saturn?
Even where this not a joke, there is a problem. When I first got interested in this topic about 1990 one of the first things I did was look at the NAS estimates about orbiting mirrors or scatters. Problem is if you use mass-efficient scatterers they are rapidly blown out of orbit by light pressure. The Russin and Flit book worth a look. There are earlier soviet reference as well. It was the engineered everything era. -David From: kcalde...@gmail.com [mailto:kcalde...@gmail.com] On Behalf Of Ken Caldeira Sent: November 23, 2009 3:21 PM To: dan.wha...@gmail.com Cc: geoengineering Subject: Re: [geo] What if Earth had rings like Saturn? When I was a post-doc at Penn State working with Jim Kasting we did calculations of changes in solar flux from rings as a possible explanation of low-latitude glaciations in the ancient past, but we didn't published them. I think we decided you would need quite a ring to freeze the equator. At that time we were not interested in more subtle effects. Here is a manuscript that looks at the issue. I haven't looked at it carefully to see if it is right: http://www.star-tech-inc.com/papers/earth_rings/earth_rings.pdf Of course, an equatorial ring would shade only the winter hemisphere. ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA kcalde...@ciw.edu; kcalde...@stanford.edu http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab +1 650 704 7212; fax: +1 650 462 5968 On Mon, Nov 23, 2009 at 1:41 PM, Dan Whaley dan.wha...@gmail.com wrote: Just for laughs... This is wonderful eye candy. http://idealog.co.nz/blog/idealist/rings-around-planet-earth Of course the question is how much cooling would they provide. It would be permanent of course. (Ah well...) Great to see the 3D renderings from the POV of different cities and different times of day Enjoy. Dan -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com mailto:geoengineering%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/geoengineering?hl=. -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=. -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineer...@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
RE: [geo] Re: Rejected - a simple argument for SRM geoengineering
Greg GWP's by design ignore all climate impacts beyond 100 years. This has real consequences as it makes methane look relatively more important that it should be, and it also overweight's the beneficial impacts of biomass sequestration in some calculations. While some traditional economists may assume that discounting allows them to ignore any impact beyond 100 years, this GWP formula has long been a point of contention as most of us do value the future of the planet beyond 100 years. Adopting a 100 year analysis horizon, as the IPCC generally does, takes our eye off the long term consequences of dumping fossil carbon in the atmosphere. The risk of sea level rise look much less serious if one only looks a century out. Scientific understanding about the long term impacts of fossil emissions is decades old (see Jim Kasting's old papers for example), popular realization of these facts is long overdue. Cheers, David From: Greg Rau [mailto:r...@llnl.gov] Sent: November 16, 2009 1:23 PM To: mmacc...@comcast.net; geoengineering@googlegroups.com Subject: Re: [geo] Re: Rejected - a simple argument for SRM geoengineering In light of recent modeling results on the lifetime of CO2 in the atmosphere, I am concerned that the current time-integrated (not instantaneous) GWP estimate for CO2 has been underestimated and hence GWP's of other gases (esp short-lived gases) relative to CO2 have been overestimated. E.g., Eby et al., 2009: http://ams.allenpress.com/perlserv/?request=get-abstractdoi=10.1175%2F2 008JCLI2554.1 show that 20-30% of excess emissions of CO2 and 60-70% of the subsequent CO2-caused surface air temp anomally exists 10,000 years after emission. Isn't this (or is this?) a far larger total time-integrated GW effect than a mass equivalent emission of CH4? Experts please set me straight. Thanks, Greg Agreed, one has to consider a time period, so assume one takes a day that when injected there is no decay over this period-so it might as well be a second of time one takes-so virtually instantaneous. And I'll assume linearity on methane absorption and logarithmic for CO2. So, for methane, humans have caused an increase of roughly 1000 ppb which converts to about 3 GtCH4, and this causes a forcing of about 0.5 W/m**2 (at the tropopause) per IPCC. For CO2, we know that a doubling (so we'll say from 300 to 600 ppm so we are in the range of interest) causes a forcing of about 3.6 W/m**2 (at the tropopause). So, 300 ppm of CO2 in the atmosphere is roughly 600 GtC or 2200 GtCO2 (and global warming potential is done for CO2, I believe. So, if we take the ratio of forcing to mass for CH4 divided by the ratio of forcing to mass for CO2, we get a rough estimate of the instantaneous GWP, so [0.5/3]/[3.6/2200] equals roughly 100 for the ratio at t=0 (so allowing for no decay) of the radiative forcing caused by a unit mass of CH4 added to the atmosphere to a unit mass of CO2 added to the atmosphere. Not exact, but plausible. Mike On 11/16/09 3:42 AM, Peter Read pre...@attglobal.net wrote: John, Andrew Re BTW, does anybody know the _immediate_ warming potential of methane? Someone will correct me no doubt but my understanding is that warming is a rate process measured in W/m^2 So instantaneous [[== immediate?]] warming is an incorrect concept Unless it continues for a second, a week, a year, 25 years, for whatever, no warming takes place. So it is necessary to multiply by a duration to get joules/m^2 It's how many joules get into the low albedo meltwater on top of Greenland's ice that decides how much gets melted each year to fall down crevasses and lubricate the eventual collapse of large areas of ice into the oceans. Meaning that the integral [[roughly]] under the CO2 level curve is what matters [multiplied by the warming potential over that period] when it comes to measuring threats of Greenland's collapse So the key issue is duration - how long elevated greenhouse gas levels last and how to get them down. Think that's right Peter - Original Message - From: John Nissen mailto:j...@cloudworld.co.uk mailto:j...@cloudworld.co.uk To: andrew.lock...@gmail.com Cc: geoengineering mailto:geoengineering@googlegroups.com mailto:geoengineering@googlegroups.com Sent: Monday, November 16, 2009 6:18 PM Subject: Re: [geo] Re: Rejected - a simple argument for SRM geoengineering Hi Andrew, You say: I don't oppose John's argument, but
[geo] Re: Sea ice: beware of hype, uncertainty cut's both ways
John We are generally in good agreement. The one point where we disagree is about how climate sensitivity is introduced into models. There is no knob for climate sensitivity in a GCM. There are many processes which are strongly nonlinear from the initiation of convection to parameterizations of sea ice and snow reflectivity. Climate sensitivity is the way we talk about (and measure) the overall response of the model to perturbations such as changes in CO2 or insolation. This is not a claim that models get it all right or that they have the sensitivity right. But it's wrong to say that models don't have the nonlinearities you described. They do, and they have for decades. It may be that they don't have them in the right way or the overall sensitivity is too high, on the other hand it may be the over all sensitivity is too low. While it's clear that there are many relatively sharp tipping points when it comes to particular climate impacts (e.g., the temperature and precipitation regime at which a particular species of tree does or does not thrive, or the conditions that make and I sheet grow or shrink), but there is substantial evidence that the climate system as a whole both in reality and in models response relatively linearly to perturbations and that it may be that very strong nonlinearities tipping points are not particularly important in understanding the risks of climate change at large-scale. Obviously this is a point on which people have different views, but there many people in the core the climate modeling community who would share the view I just gave despite the hype about tipping points. The most important tipping point seems to involve the North Atlantic overturning circulation, and that may have had something to do with mediating the instabilities between glacial interglacial states, however it is less reason to believe that this instability will operate between the current climate and warmer climates. We had this conversation the MIT meeting and Dave Battisti expressed exactly this view. This is not in any way to minimize climate risks, the simple fact of very large uncertainty in the overall climate sensitivity combined with the uncertainties in nonlinearities in many of the impacts means that there is a significant chance of dramatic even for some of us catastrophic climate impacts with the current CO2 trajectory. It's just a statement that you don't need to overdo the idea of tipping points to see this. Yours, David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of John Nissen Sent: November 2, 2009 4:10 PM To: David Keith Cc: climateintervent...@googlegroups.com; geoengineering@googlegroups.com; Ken Caldeira; Julian Norman; Mike MacCracken Subject: [geo] Re: Sea ice: beware of hype, uncertainty cut's both ways Thank you, David, for your thoughtful reply and the excellent points you make, which culminate in an acknowledgement of the argument for albedo geoengineering to save the Arctic sea ice, as I have been proposing. Your support is most welcome. Re your point 1, the proposal does not assume a particular estimate for date of disappearance of Arctic sea ice. There are two arguments here. The first is that it better to apply the geoengineering before the positive feedback grows any stronger. (As Mike puts it, it is better to put out a small fire rather than wait until the whole building is aflame.) The second argument is to take the precautionary principle, and consider the soonest time for disappearance within the possible range of times. Here the very uncertainty that you highlight is giving us a significant probability of ice summer disappearance within a few years, even if the most likely date (aka median date) may be a few decades away. Re point 2 and the models, the typical models give a climate sensitivity factor, which is essentially linear and assumes tipping points are not reached. However, with the Arctic sea ice we may be seeing tipping already in progress, due to non-linear effects and positive feedbacks which are notoriously difficult to model. Furthermore, the Arctic sea ice may never have totally disappeared in any interglacial period of the past 2 million years; and the maximum temperature of recent interglacial periods will soon be exceeded. So we are moving into uncharted waters. Thus the assumption that global warming will proceed linearly with CO2 (i.e. with constant climate sensitivity factor) seems debatable. Therefore there is all the more reason to try and save the Arctic sea ice. Re point 2 and the methane, again one could argue for a precautionary approach. Some scientist estimate that there is enough methane to more than double GHG forcing if it were released. Halting the Arctic warming would greatly reduce the risk. Re point 3, it is good to see that experts from IPCC now acknowledge that they grossly underestimated the risk
[geo] Re: Arguments against geoengineering
I think the idea that fossil resources will provide a meaningful constraint on CO2 emissions does not pass a fact checker's laugh test. We have enough carbon within the growing reach or our extraction technologies to push CO2 concentrations beyond 5,000 towards 10,000 ppm. For my own lay-language debunking of this idea in a popular book see: Keith, David. (2009) Dangerous Abundance. IN: Homer-Dixon, T. Garrison, N. (Eds.) Carbon Shift: How The Twin Crises Of Oil Depletion And Climate Change Will Define The Future, Toronto: Random House of Canada, pp26-57. Available at: http://people.ucalgary.ca/~keith/Preprints.html. -David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Christopher Mims Sent: October 30, 2009 7:35 AM To: geoengineering Subject: [geo] Re: Arguments against geoengineering Emissions in 2020 emissions in 2010 also assumes that there is nothing that would limit the material inputs that will lead to those emissions. You don't have to be a disciple of 'limits to growth' to recognize that at some point, we'll start bumping our head against a ceiling determined by the carrying capacity of the planet. Even the conservative IEA believes that maximum historical production of liquid fuels (peak oil) will arrive within the next decade. If you believe more pessimistic estimates, net production of liquid fuels has already peaked (2008) and our civilization's near total dependence on oil for transportation means emissions from the transportation sector will only shrink going forward. Whether or not any of this is true is anyone's guess - but it is an example of an X factor, beyond technology, that is within the realm of possibility. (Another, and related, X factor is a second or an ongoing global recession. Just look at what the one we're in now did to global CO2 emissions.) In other words, legislation and conservation is not the only thing that will determine maximum annual CO2 emissions from anthropogenic sources - in fact these might be the two factors that are *least* likely to determine the ultimate level of those emissions. On Oct 30, 8:42 am, Alan Robock rob...@envsci.rutgers.edu wrote: Dear Dan, Dangerous anthropogenic inteference is now commonly defined as 2°C about preindustrial global average temperatures (about 1°C above current levels). Certainly it is not a step function, and impacts increase with temperature change, and we are already experiencing some. So we need a lot of adaptation, too. Alan Alan Robock, Professor II Director, Meteorology Undergraduate Program Associate Director, Center for Environmental Prediction Department of Environmental Sciences Phone: +1-732-932-9800 x6222 Rutgers University Fax: +1-732-932-8644 14 College Farm Road E-mail: rob...@envsci.rutgers.edu New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock On Fri, 30 Oct 2009, Dan Whaley wrote: Alan, I agree that 450 or 500 are theoretically achievable with emissions reductions-- clearly. (Though either would effectively require immediate and aggressive reductions from everyone, now). But if we're already seeing impacts we don't like, and we know the impacts considerably lag the forcing, what leads us to believe these are acceptable levels? Dan On Oct 29, 7:18 pm, Alan Robock rob...@envsci.rutgers.edu wrote: Dan, Where do you think we need to be? And when? If it is 350 ppm soon, of course not. That would take massive carbon capture from the atmosphere and very rapid reductions in emissions. But if you want to stop somewhere between 450 and 500 ppm, adapt, and then gradually reduce the concentration with carbon capture, I think we can do that with carbon capture from the stacks of coal-fired plants, and rapid transition to an electric economy with solar and wind generation. It would need a substantial and regular increase in the price of carbon emissions. Not being a political scientist, I cannot predict how likely this is, not that political scientists can either, but it is certainly possible. If climate change is the greatest threat to world security, the resources now being spent on the military (and half of the scientists and the engineers in the US working for them) can certainly be redirected to this goal. We need not accept the status quo as a predictor of the future. Alan Alan Robock, Professor II Director, Meteorology Undergraduate Program Associate Director, Center for Environmental Prediction Department of Environmental Sciences Phone: +1-732-932-9800 x6222 Rutgers University Fax: +1-732-932-8644 14 College Farm Road E-mail: rob...@envsci.rutgers.edu New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock On Thu, 29 Oct 2009, Dan Whaley wrote:
[geo] Re: Royal Society report - Temperature rebound a myth?
My two bits into this interesting debate: On the temperature rebound. As Ken says, there is no question that the temperature rebound is real. Simple physics tells you it should be there, and this is confirmed by experiments with at least three different GCMs. The question is: is it a bug or a feature? I lean towards feature, and I don't take the termination risk all that seriously. One of the central advantages of SRM geo is the speed of action. In simple economic formulations it is the speed that is the principal value because you can decide how much to implement after uncertainty about climate sensitivity is resolved (See #117 at www.ucalgary.ca/~keith/geo.html). You could also shut it off if something goes wrong. Yes, I know about hysteresis but having fast control is still better than not having it. In a recent debate about this topic someone proposed three example scenarios were one would consider fast response a termination risk: Possible reasons for early and rapid termination would include (e.g.) ocean acidification proves to be much worse than expected, deleterious health or ecological effects of less direct radiation are discovered (think about bees), ditto for high CO2 on plants or insects, the future world government is taken over by religious maniacs who consider SRM to be a violation of Gaia, or something like that, etc etc. I still don't see it as a risk. Here are my three answers from that debate: 1. If we find that the effects of high CO2 on ocean plants or insects are intolerable, then we need a crash program on negative emissions: biomass with capture, burying trees, putting alkalinity in the oceans. Halting SRM will not help; indeed it may hurt since there is evidence that some SRM may slightly increase NPP so slightly increasing carbon flux to biosphere. This is the most common and seemingly credible concern regarding termination risk but, in my view, it confuses cause with effect. Even if it's true that one has decided to put more CO2 in the air because of SRM (that is, SRM as cause) the discovery that the CO2 is more dangerous than expected (the effect) is a reason to focus on CDR not to stop SRM. 2. If religious maniacs take over the government I think the problem is religious maniacs not the reversibility of SRM. This scenario boils down to saying that the danger is that we will decide to turn it off. But in my mind is that doesn't count a risk. I like having an adjustable thermostat my house. Of course, there's some chance that my 12-year-old will decide to turn it all the way down in protest against the evils of parental rule. However, on can see this as a risk associated with the thermostat or a risk of having rowdy kids. If this is a risk it's the precise converse of a benefit. 3. Given that there are many methods to achieve SRM, and given that as we described in the Novim report, one would gradually work our way up to full scale, I find it hard to imagine a scenario in which it was suddenly reveal that there was a danger with a particular method that did not allow substitution of a alternate method. Suppose the engineered nanoparticles deadly cancer after a 10 year incubation period? Under the slowly work your way up scenario while the discovered the deaths a decade before you went to full-scale. But ignoring that; and assuming one suddenly figures out that the engineered particles must be taken out one could go back to just plain sulfur. We know that sulfur doesn't have a similarly obscure deadly effect since we tried it with Pinatubo. That said, it is of course true that the possibility of rapidly modulating the climate poses risks in a world with many competing actors. If the drivers are fighting, ut's more dangerous to be in a high-performance sports car then in an old clunker with stiff steering response. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~--~~~~--~~--~--~---
[geo] Re: Royal Society report - Temperature rebound a myth?
Greg, Let me push back a bit. I absolutely agree that experiments are crucial and that by working our way up in experimental scale we will learn more and therefore reduce risk. While we did not say this as clearly in the RS report as we might have, and not as clearly as in Novim, I don't believe the RS contradicts this view. Also, I and several others of the report have more experience as experimentalists than as modelers. Cheers, D -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of xbenf...@aol.com Sent: September 6, 2009 12:30 PM To: j...@cloudworld.co.uk; kcalde...@stanford.edu Cc: geoengineering@googlegroups.com; wig...@ucar.edu; s.sal...@ed.ac.uk Subject: [geo] Re: Royal Society report - Temperature rebound a myth? Throughout these studies, few realize that this is engineering. Learning how the global system operates is best accomplished by experiments that scale up as we learn, accompanied by simulations. Issues of risk are nearly meaningless at early stages. Real risk falls as you learn. The death rate in aviation in its first decade was nearly 10%! Still, people did it. Nor does the RAS report seem to understand how scaling of experiments works. Maybe that's because few of them have ever done lab experiments; simulations are a very different game--a form of theory, really. Gregory Benford -Original Message- From: John Nissen j...@cloudworld.co.uk To: Ken Caldeira kcalde...@stanford.edu Cc: Geoengineering geoengineering@googlegroups.com; Tom Wigley wig...@ucar.edu; Stephen Salter s.sal...@ed.ac.uk Sent: Sun, Sep 6, 2009 11:12 am Subject: [geo] Re: Royal Society report - Temperature rebound a myth? Hi Ken, We may disagree about the rebound of SRM termination, but we agree about the sense. Indeed turning off SRM has been likened to turning off the kidney dialysis machine of a patient with kidney failure. (Thanks, Stephen, for that thought.) So why did the Royal Society report mark Stratospheric aerosols with an H for high risk in table 3.6; and 2/5 for safety in table 5.1? You were a member of the working group! I note that Cloud albedo al so gets an H for Regional climate change. But isn't that a huge advantage of the method over stratospheric aerosols - that it can be more targeted to cool particular areas? Every way that a method can be tuned, or targeted more closely, means that there is more scope for avoiding side-effects - thus is a safety bonus. (Being able to turn off the SRM may also allow you to react to unexpected side-effects - another bonus.) Cheers, John --- Ken Caldeira wrote: See attached paper ... If you turn off solar deflection you would get rapid warming (no overshoot, but a rapid rebound). This is not a myth that needs refuting. The question is: What does this mean? There are plenty of things that we do that, were they stopped suddenly, we would be in big trouble. For example, if we stopped pumping oil today, our transportation system and therefore food distribution system would grind to a halt and there would be mass starvation. Does this mean that it would be crazy to base a food distribution system on oil? Or does it mean, if you are going to base a food distribution system on oil, you had better be pretty sure you can assure a nearly continuous flow. I think the rapid rebound means that everyone will be incented to make sure that the amount of solar radiation deflection is modulated with=0 D care. The fact that stopping SRM suddenly could bring big problems means that we would take great care not to stop suddenly. If we stopped generating electricity we would be in big trouble. If we stopped piping water we would be in big trouble. If we stopped hauling garbage we would be in big trouble. Etc, etc. Our response to these threats is not to say: no electricity, no water pipes, no garbage hauling, etc. Instead we say, let's assure continuity, as best we can, of electricity, water piping, garbage hauling, etc. ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA kcalde...@ciw.edu; kcalde...@stanford.edu http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab +1 650 704 7212; fax: +1 650 462 5968 On Sun, Sep 6, 2009 at 8:38 AM, John Nissen lt;j...@cloudworld.co.ukgt; wrote: At the launch of the Royal Society report, it was explained that a disadvantage of SRM was if you suddenly stopped it, because the temperature would rebound due to all the CO2 that had accrued in the meantime, with its suppressed warming effect. This termination effect is expressed as a high risk, see table 3.6 [1] with footnote [2]. It so happens I have just looked through Tom Wigley's file on the geoengi neering googlegroup: http://groups.google.com/group/geoengineering/files In this presentation he
[geo] Research Councils UK Energy Programme announces funding support for Geoengineering research
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[geo] Re: Fwd: costs of air capture - Royal Society report
Roger, It was a group report, while I contributed to the air capture section we were careful that I did not have final word since I have a strong self-interest in making air capture look good. I certainly know about your work and it came up in discussions about air capture in the group. I don't think your paper contradicts the RS summary, but I suggest we take that conversation off-line to get some resolution. I don't think there is a simple cost-benefit analysis argument that distinguishes between carbon reduction and solar radiation management, they are apples and oranges. Reducing emissions and /or carbon removal is a necessary but not sufficient response to climate risk, but given the uncertainty in the climate's response to CO2 and we cannot be sure that emission reductions alone will allow us to avoid dangerous climate risks. This is true even when one includes carbon removal because of the technological and carbon cycle inertia. SRM is fast and cheap, yet it cannot fully compensate for the climate risk of elevated carbon dioxide. SRM is sufficiently cheap that decisions about its use will almost certainly be risk-risk decisions not cost-benefit decisions. See, for example, the geo decision analysis preprint, #117 on the geo section of my site: www.ucalgary.ca/~keith/geo.html On air capture, I have a perspective that will be out in two weeks in Science. Yours, David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Ken Caldeira Sent: September 3, 2009 7:58 AM To: geoengineering Subject: [geo] Fwd: costs of air capture - Royal Society report on behalf of Roger Pielke Jr [ In brief reply: With David Keith as co-author of the report, we relied heavily on his assessment in this area. -KC] All- It is interesting that my paper on the costs of air capture was ignored by the Royal Society committee on geoengineering (as I am told by a member that it was made available to the Committee, and it is the only such effort focused on comparing costs to IPCC and Stern-type estimates): Pielke, Jr., R. A., 2009. An Idealized Assessment of the Economics of Air Capture of Carbon Dioxide in Mitigation Policy http://sciencepolicy.colorado.edu/admin/publication_files/resource-2716 -2009.03.pdf , Environmental Science Policy, Vol. 12, Issue 3, pp. 216-225. Perhaps the Committee thought the analysis was so deeply flawed as to not be of value (?? If so, none has yet shared this perspective with me). Even so, surely the readers of the report would have benefited from hearing in what ways the paper is flawed rather than just pretending that it does not exist. Instead of the RS providing a comprehensive review, there exists a peer-reviewed paper on the costs of air capture that contradicts some of the views on air cpature costs expressed in the RS report (maybe that is the explanation). To the outsider it does make the Committee look uniformed or less-than-comprehensive. Perhaps the members of the committee on this list might want to comment? I offer some comments here: http://rogerpielkejr.blogspot.com/2009/09/air-capture-in-royal-society.h tml In other news, yesterday I argued in terms of cost-benefit analyses against SRM and in favor of AC as a tool in the climate policy tool box before Bjorn Lomborg's panel of Nobel Prize winning economists. They are supposed to report out tomorrow, and we'll see what they come up with. Lomborg has been writing op-eds suggesting that SRM could be an alternative to conventional mitigation. I strenuously opposed this view before the panel. I'll comment about the process on my blog from my vantage point upon release of the report. Best regards, Roger Roger Pielke, Jr. University of Colorado --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~--~~~~--~~--~--~---
[geo] Re: ETC Group on Royal Society Report: The Emperor's New Climate: Geoengineering as 21st century fairytale
Diana, Call me old-fashioned, but I believe deeply in the virtues of transparency and honesty in debating matters as important as this. I welcome skepticism about geoengineering. However, the disconnect between your press release and what is actually being suggested by the Royal Society report, or for that matter your private comments to me at the NAS meeting are disappointing. The way the ETC group has managed this, suggest to me not skepticism but its precise opposite closemindedness. I suspect that you don't want to live in a world where debate gets reduced to soundbites and interest group fight to distort facts to the maximum yet seems to me that is where the ETC Group is leading here. Why for example release a commentary with ad hominem comments like tricksters before you have even had a chance to look at the Royal society report. I note that ETC has a base in Ottawa, my hometown, and you could easily have taken the time to talk to me (as I have offered), but instead it seems that ETC would prefer to hold strong opinions without actually engaging substantively with other views. Is this really how you want to see public debate on important issues? Yours, David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Diana Bronson Sent: August 28, 2009 1:35 PM To: geoengineering@googlegroups.com; climateintervent...@googlegroups.com Subject: [geo] ETC Group on Royal Society Report: The Emperor's New Climate: Geoengineering as 21st century fairytale ETC Group News Release 28 August 2009 www.etcgroup.org SCIENCE FICTIONS: UK'S ROYAL SOCIETY TO ISSUE MAJOR REPORT ON GEOENGINEERING SEPTEMBER 1; BAN REAL-WORLD EXPERIMENTS, SAYS ETC GROUP The oldest scientific academy in the world, the UK's Royal Society, will release its long-awaited report on geoengineering September 1st 2009 in London. The report, drafted by a panel dominated by geoengineering enthusiasts, is widely expected to recommend that the government support more research and perhaps even real-world experimentation of these controversial new technologies that intentionally manipulate the earth's climate on a large scale with the aim of lessening the effects of climate change. Geoengineering is a bad idea, and, unfortunately, it may transform Lord Rees's book from musings to memoir, says Diana Bronson, researcher for the international technology watchdog ETC Group, referring to the Royal Society President's 2004 book, Our Final Century, which suggested that humans may not live to see the end of the 21st century. Geoengineering can refer to sulphate-injections in the stratosphere and cloud-whitening to reflect sunlight away from the earth, fertilization of the oceans with iron nano-particles to try to increase their carbon-carrying capacity, intentionally modifying global weather patterns, among other techniques. The Royal Society may be cautious in their report but, in fact, when it comes to geoengineering, a yellow light can quickly turn green. For the climate to take notice, any geoengineering scheme would have to be massive - sulphate particles or whitened clouds would have to deflect a lot of sunlight and ocean fertilization would have to cover great swathes of sea. Even the most careful computer models won't be able to predict what will happen if an experiment is scaled-up and moved out of doors, argues Bronson. If governments believe there is a techno- fix to the climate change conundrum that will let them off the hook at the climate change treaty negotiations in Copenhagen, they will throw precious time and dollars at sci-fi fantasies, overlook potentially devastating side effects and divert their attention from the urgent need to reduce carbon emissions at source. ETC Group's new special report, The Emperor's New Climate: Geoengineering as 21st century fairytale, questions the narratives commonly used by the geoengineering lobby to advance their agenda. Contrary to what geoengineers are saying, this is a costly time- waster, says Bronson. The report calls for a broader international discussion and concludes that any effort to experiment these technologies in the real world is nothing short of geopiracy and should be banned. ETC Group's special report, The Emperor's New Climate: Geoengineering as 21st century fairytale, is available on the Internet at http://www.etcgroup.org/en/materials/publications.html?pub_id=762 -30- For more information: Diana Bronson (Montreal, Canada) di...@etcgroup.org Phone: +1 514 273 6661; cell +1 514 629 9236 Kathy Jo Wetter (Durham, NC, USA) k...@etcgroup.org Phone: +1 919 688 7302 Silvia Ribeiro (Mexico City) sil...@etcgroup.org Phone: 011 52 6326 64 Molly Kane (Ottawa, Canada) mo...@etcgroup.org Phone: +1 613 241 2267, ext 26; cell +1 613 797-6421 --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups geoengineering group. To post to this
[geo] Re: Ecologists weigh in
-scale geoengineering scheme is fertilizing the oceans with iron to increase carbon uptake from the atmosphere. Charles Miller of Oregon State University says that ocean fertilization could create a rise in iron-limited phytoplankton populations, which by dying and sinking would use enough oxygen to create extensive dead zones in the oceans. In addition, he says, the maximum possible rate of ocean iron fertilization could only offset a small fraction of the current rate of carbon burning by humans. Ocean fertilization also does not alleviate the increasing problem of ocean acidification, caused by carbon dioxide from the increasingly carbon-rich atmosphere dissolving into seawater. In fact, Miller says, ocean fertilization schemes will likely exacerbate this problem. Any large-scale fertilization could cause risks to ocean ecosystems as great as those of global warming itself, he says. Despite its apparent hazards at the global scale, Jackson thinks that research should continue on safer ways to use geoengineering at a smaller scale. Geologic sequestration, sometimes known as CO2 capture and storage, takes CO2 out of the atmosphere and stores it in underground reservoirs. Jackson says that this solution has the potential to store more than a century's worth of electric power emissions at a relatively low cost. He notes, however, that some potential risks of geologic sequestration include carbon leakage and the potential for interactions with groundwater. But on the planetary scale, most ecologists are skeptical of climate engineering. Playing with the Earth's climate is a dangerous game with unclear rules, says Jackson. We need more direct ways to tackle global warming, including energy efficiency, reduced consumption, and investment in renewable energy sources. ### Clifford Duke, Director of Science Programs at the Ecological Society of America, is co-organizer of the symposium. Additional speakers include David Keith from the University of Calgary and Phillip Duffy from Climate Central, Inc. The researchers will present their results in: Symposium 21 - The Environmental Effects of Geoengineering Thursday, August 6, 2009, 1:30 PM-5:00 PM Pecos room, Albuquerque Convention Center For more information about this session and other ESA Annual Meeting activities, visit http://www.esa.org/albuquerque. The theme of the meeting is Ecological Knowledge and a Global Sustainable Society. More than 3,500 scientists are expected to attend. The Ecological Society of America is the world's largest professional organization of ecologists, representing 10,000 scientists in the United States and around the globe. Since its founding in 1915, ESA has promoted the responsible application of ecological principles to the solution of environmental problems through ESA reports, journals, research, and expert testimony to Congress. ESA publishes four journals and convenes an annual scientific conference. Visit the ESA website at http://www.esa.org. Subscribe to ESA press releases by contacting Christine Buckley. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~--~~~~--~~--~--~---
[geo] Re: The International Maritime Organisation's plans to warm the world
A few comments. 1. Am CCing my colleague Jim Corbett, who wrote a bunch of the important papers on emissions from shipping, is an author of the latest paper mentioned her, and as worked with the IMO on this. Jim: any discussion on this tradeoff at IMO? 2. Some ships already dual fuel (bunkers and natural gas), where the NG is burned in and near port to comply with local air quality. 3. Numbers only work against bifurcated system if no policy to preserve or promote sulfur emissions in open ocean. 4. Work needed to estimate the ratio of climate forcing to heath impacts of S emissions as a function of the location of the emissions, this would allow where it make most sense to promote or restrict emissions. I will pitch this to atmo chemists at their Gordon Research conference this evening. 5. We don't just want to leave ship emissions as they are because we will need manage NOx even if we want S emissions. Both are big from ships. See Jim's paper: J. J. Corbett and P. S. Fischbeck, Emissions from Ships, Science, vol. 278, no. 31 October 1997, pp. 823-824. 6. The idea that we can use the S for geo is likely irrelevant. There is ample S as H2S in sour gas either produced and re-injected or made into elemental S using Claus process. (There are many megaton-scale blocks of elemental S from this process in Alberta where I live, stunning yellow patches on the landscape.) -David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Alvia Gaskill Sent: August 20, 2009 1:07 PM To: kcalde...@stanford.edu; geoengineering; Climate Intervention Subject: [geo] Re: The International Maritime Organisation's plans to warm the world The actual experienced level of sulfur in bunker fuels is now around 2.7%, so the reduction isn't going to be a factor of 10. And it will require a significant effort on the part of refiners to achieve the target levels, so some slippage is likely. I also doubt that ships will be equipped with high sulfur and low sulfur fuels, although some ships that do mainly transoceanic routes like container ships may be given waivers to use only high sulfur fuel in order to keep the aerosol levels up. At some point, however, the numbers work against such a bifurcated system and low sulfur will prevail, the other fuel simply no longer available in meaningful quantities. The reduction in negative forcing from tropospheric sulfate aerosols will continue as Paul Crutzen predicted. Not only will the contribution from shipping eventually become negligible, but the same will be true for coal and distillate fuels used on land and in air transportation. All told, the loss of these aerosols may be as much as 1.6W/m2 by 2050 if not sooner. The good news out of this besides the improvement in air quality is that more sulfur in the form of H2S and SO2 will become available for use in stratospheric aerosols if that approach is adopted. Regardless, the real global warming is just getting started. --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~--~~~~--~~--~--~---
[geo] Re: Televised debate
David While there is legitimate and sensible argument about how much warming we might get from anthropogenic CO2, I think the overall physics and atmospheric science linking anthropogenic CO2 emissions to the expectation of increased warming is as solid as about anything in science. The set of people who have actually rolled up their sleeves do work serious work in atmospheric science and who also believe that there is no connection between increased CO2 and warming is all but empty. Of course, there are people who passionately believes there are aliens on Air Force bases in Nevada, and likewise there are folks who have very strong opinions about how the climate science is fundamentally wrong, but I've yet to run into any of them who hold such opinions and actually know the underlying science. Do not over-read this statement. Of course, there are many thoughtful scientists who think that the environmental risks posed by anthropogenic climate change are overhyped (they often are), and also folks who believe climate sensitivity will be on the lower end of the scale (it may be). Finally, your latter assertion is simply false. Discussion of the concept of geoengineering arose in the 60's out of concern about CO2 driven climate change. See #26 at www.ucalgary.ca/~keith/Geoengineering.html. The actual name arose in the late 70s out of the same concern. Yours, David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of David Schnare Sent: May 3, 2009 2:30 PM To: kcalde...@globalecology.stanford.edu Cc: ronald.da...@earthlink.net; ds...@yahoo.com; geoengineering Subject: [geo] Re: Televised debate Ken: There is no argument about long-term global warming. That warming, if it continues, will justify geoengineering. There is, however, significant argument as to the causes of global warming. Indeed, there if far more valid, science-based argument made by well respected university academics working specifically on the issue, as to the causes of global warming, by far, than there is argument over biological evolution or plate tectonics. To characterize the argument regarding the causes of global warming as in the same state of knowledge as biological evolution or plate tectonics is not merely in error, it is an unwelcome damper on legitimate research into these phenomena. A public presentation on geoengineering need never address the causes of global warming other than as necessary to discuss the physics of management techniques. Direct cooling efforts such as Solar Radiation Management do not rest on the cause of global warming, only on the fact of that warming. Carbon sequestration techniques do presume a major greenhouse gas component. Any discussion of carbon sequestration techniques should be conditioned on a clear statement of the presumption. Whether carbon is at the heart of the warming problem need not be argued or discussed, other than for purposes of predicting the likely degree of cooling expected from any particular geoengineering technique. Finally, geoengineering rose out of a concern of a pending ice age, not out of concern about any anthropogenic global warming. Overall, geoengineering is intended to be a large scale response to climate change, whether human or natural. David Schnare On Sun, May 3, 2009 at 1:32 PM, Ken Caldeira kcalde...@globalecology.stanford.edu wrote: It is not a distraction. A good mechanistic understanding of causes of change is essential. If you do not understand the mechanisms behind global warming, how can you sensibly intervene in the climate system? How can you simultaneously believe that (a) you can add a bunch of radiatively active gases to the atmosphere and not affect climate and (b) you understand how affecting Earth's radiation balance will affect climate? There is no argument about whether most global warming is anthropogenic, just as there is no argument about whether there is biological evolution or plate tectonics. ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA kcalde...@ciw.edu; kcalde...@stanford.edu http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab +1 650 704 7212; fax: +1 650 462 5968 On Sun, May 3, 2009 at 9:05 AM, Ron ronald.da...@earthlink.net wrote: To some extent the whole argument about whether global warming is anthropogenic is a distraction. Regardless of cause, understanding global warming enough to counter it is more important. We may need to rank possible solutions according to how fast and cheaply we can implement them. We may need a two or three tier approach, implementing the first tier to buy us enough time to do the next tier. The vast changes in forest, ocean plants, combined with projected increases in new coal fired power plants present a daunting challenge. We will need to continuously
[geo] Re: Televised debate
I was just about to send links to the same. The reason it's relevant, is that this undercuts the common claim that concern about warming is recent and that atmospheric scientists in the 60s and 70s were mainly concerned about cooling. When you read the relevant documents (that is the high-level synthesis reports that should have been people's best shot at the science) the answer is the opposite, folks were worried about warming due to CO2 for exactly the same reasons they are now. We have fancier models, but the underlying physics is still simple and convincing. As in any case where a signal gradually sticks its head up above the noise there's room to argue about exactly how much of the 20th century warming is anthropogenic. But it's not the 20th century warming, nor the correlation between CO2 concentrations and temperature that are the basis of concern. The fundamental reason for concern is the same as it was when the report was written for President Johnson. It was cooling then, but it was clear that substantial increases in atmospheric CO2 would drive warming. We know much more now, but the issue is the same. We are worried about the consequences of a CO2 doubling or tripling under business as usual would happen on a timescale approximately 10^5 times faster than the decline in CO2 concentrations from the PETM to about 10 M years ago. I think it's just nonsense to say that a discussion of geoengineering need not be encumbered by this science. If this science was fundamentally flawed, as it would have to be if CO2 turns out not to be a major forcing, then there would be little basis to trust the science that underlies the understanding of geoengineering. Yours, David From: kcalde...@gmail.com [mailto:kcalde...@gmail.com] On Behalf Of Ken Caldeira Sent: May 3, 2009 10:29 PM To: David Schnare Cc: David Keith; ronald.da...@earthlink.net; ds...@yahoo.com; geoengineering Subject: Re: [geo] Re: Televised debate The report to Johnson is available at: http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab/Caldeira_Research_ge orefs.html A direct link to the pdf is at: http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab/Caldeira%20downloads /PSAC,%201965,%20Restoring%20the%20Quality%20of%20Our%20Environment.pdf I attach jpegs of two relevant passages that make it clear that global warming (not cooling) was the concern. On Sun, May 3, 2009 at 5:45 PM, David Schnare dwschn...@gmail.com wrote: David: I must rely on you for the history of geoengineering, that being one of you academic interests and areas of expertise. My reference to the beginning of geoengineering was to the discussions in the Johnson White House related to what then was thought likely to be global cooling, and alternative means to mitigate such cooling. I do not recall what folks were saying would be the cause of such cooling, but I don't believe it was CO2. With regard to greenhouse gases and global warming, I did not state that they had no forcing effect. The argument is as to the size of their role, and GHGs significance as compared to natural cycles. That argument is ongoing, and people who have actually rolled up their sleeves do work serious work in atmospheric science include many who discount CO2 as a major forcing. That set is not empty, and if you want a list, I can jin one up. It would include former authors and lead authors for the IPCC. I do agree that those who believe there is no connection between increased CO2 and warming are wrong. I agree because you used the phrase no connection. The argument is about how much connection there is. Finally, you did not respond to my suggestion that for SRM related approaches, it does not matter too much as to the GHG versus natural cycles arguments. SRM is a bandaid, not a cure. Carbon sequestration, on the other hand, is a cure, but only if GHG forcing is a significant contributor to the forcing. If, however, GHGs are not a large element of warming, they remain a potentially large element of ocean acidification, and thus carbon sequestration still remains an important potential means to address a global problem. Thus, a cogent discussion on geoengineering need not be encumbered by arguments about causality of climate change. Those seeking carbon emissions reductions, include many of whom study geoengineering. Those folks do not wish to ignor, diminish or dispute the need for carbon reduction. Others interested in geoengineering, but not as concerned about GHGs, are more agnostic on carbon reduction, but believe geoengineering should not be used as a response to the AGW alarmists' arguments. Rather, they recognize the potential need for geoengineering on other grounds, and simply discount the moral dilemma argument. David Schnare. On Sun, May 3, 2009 at 4:48 PM, David Keith ke...@ucalgary.ca wrote: David While there is legitimate and sensible argument about how
[geo] FW: McClean's article --geoengineering!
Folks, This is the most dramatic piece of hate mail I have yet received. The only upside for a personal point of view is that he says i leave vengence to God. This one is interesting in linking chemtrails with HAARP and illuminating the mixture with an apocalyptic strain of religious fundamentalism. The letter refers to the cover story on Canada's leading newsmagazine which covered geoengineering: http://www2.macleans.ca/2009/04/22/plan-b-for-global-warming/ Yours, David From: paul w [mailto:paulw...@yahoo.com] Sent: April 26, 2009 4:59 PM To: David Keith Subject: McClean's article --geoengineering! Hello, After reading the article ,i cannot believe that you can lie like this come on, thousands of people know that planes have been spraying polymars,mold inhibiters,aluminum,barium and titanium which was started in 1998 and it's called the SHIELD PROJECT by scientists and CHEMTRAILS by the general publicSHAME how can you lie through your teeth that you are just about to begin sprayingany idiot can look up at the skies almost everywhere in the world and see planes intentionally spraying these toxins into our atmosphere-how can you have studied geoengineering all these years and not be aware than this GENOCIDE is taking place and GENOCIDE it is because CHEMTRAILS are increasing suicide rate amongst people,killing the birds,bees ,trees,fish,changing the texture of the snow and increasing severity of river floods and on and on and on!--it is the most evil thing that has ever been undertaken in the history of the human race and Yahweh Most High God is going to punish you more severly than Hitler and Stalin combined, forever and ever in the Lake of Fire where your worm will not die and the fire is not quenched and God has a special flame for the wicked!you must be another one of those who are insane from the evolution lieeven the devils tremble before God you fools and God is going to show you what you missed you disgustingly evil scientists--and the fact that you keep lying to the public proves that what you are doing is evil and God abhors liars worse than murderers---i leave vengence to God but i have a feeling when the godless masses find out that it's lying scientists causing climate change with their H.A.A.R.P. Sites and chemtrails and other wicked experiments ,the masses are going to go balistic like never before in history-you don't even love your own children if you can lie like you do for a living -if you want to know what the next 50 years of hell are going to be like the study the Book of Revelation in the King James Bible and i guarantee you that NOT ONE WORD will fail---around 2060 Yahshua the Messiah will return with 200,000,000, reaping angels from the far end of Heaven and throw the wicked into the Lake of Fire cannot break the Word of God so if you want to be in Yahweh's beautiful Kingdom on a supernaturally renewed surface of earth where His people will live in peace then start REPENTING OF YOUR LIES and EVIL EXPERIMENTS---there will be much wailing and gnashing of teeth sincerely Paul --Satan has a short time--50 years!---CANNOT SAVE THE EARTH2Peter3:10 --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~--~~~~--~~--~--~---
[geo] Re: EGU meeting, April 19-24
Alan You imply a geoengineered Pinatubo would reduce crop productivity in a high-CO2 world. Can you provide some argument to support the case? It's true that because of change in surface energy balance you reduce precip more than temps, so that if temps are back to pre-industrial mean the precip is down. But in a geoengineered climate, evaporation is also down. So is precipitation variability. Total precip does not determine the outcome in any simple way. My guess, supported by the studies with coupled ecosystem models, is that solar shielding would increase crop productivity and NPP vs a high-CO2 no-geo baseline. Of course, the effects would not be uniform. Yours, David -Original Message- From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Alan Robock Sent: April 21, 2009 6:54 AM To: Ken Caldeira Cc: j...@cloudworld.co.uk; geoengineering Subject: [geo] Re: EGU meeting, April 19-24 Dear Ken, If Mt. Pinatubo is the poster child, then this poster will contain drought in large parts of the world. You can see the figures in the Trenberth and Dai (2007) GRL paper. And don't forget, the effects of Pinatubo only lasted for a year. A 1-year climate anomaly will not be that devastating, as food reserves and trade can compensate for agricultural shortfalls. But a permanent aerosol cloud will make these effects last for decades. So your poster, using Pinatubo as an example, argues against geoengineering with stratospheric aerosols. The ozone depletion from Pinatubo tells the same story, but I have not seen a study of how large the effects of that much enhanced UV would be on the ecosystem and humans. I agree that the acid deposition would not seem to be a serious problem, as we showed in our paper now under review at JGR. Alan Alan Robock, Professor II Director, Meteorology Undergraduate Program Associate Director, Center for Environmental Prediction Department of Environmental SciencesPhone: +1-732-932-9800 x6222 Rutgers University Fax: +1-732-932-8644 14 College Farm Road E-mail: rob...@envsci.rutgers.edu New Brunswick, NJ 08901-8551 USA http://envsci.rutgers.edu/~robock On Tue, 21 Apr 2009, Ken Caldeira wrote: For future sulfur emissions, see http://www.ipcc.ch/ipccreports/sres/emission/5-20.htm For past sulfur emissions, see the attached paper. Current sulfur emissions are on the order of 50 Tg/yr and for this half century is likely to be in the range of 50 to 100 Tg/yr. The EGU abstract ( http://meetingorganizer.copernicus.org/EGU2009/EGU2009-4831.pdf) foresees emissions rates of 5 to 10 Tg/yr for the first half of the century, which is roughly the 10% range of current emissions, with this percentage scaling up if greenhouse gas concentrations continue to increase and tropospheric sulfur emissions decline. So, this is not negligible, but it is unlikely to be a game changer either. It is my view that there would need to be some mighty compelling reasons to deploy a stratospheric aerosol system, if not only because people who experience bad weather in subseuqent years might be incented to sue (or even attack militarily) parties engaged in aerosol release. So, if we in an emergency situation acid rain, ozone loss, etc would be among the costs taken into account before making a decision, but these costs may not be decisive. I still think Mt Pinatubo is the poster child for stratospheric aerosols approaches: We know it can cool the Earth, we know it can do this quickly, and we know it does not immediately cause a global catastrophe. Were we faced with a real climate emergency, there could be a lot of pressure to exercise the Pinatubo option. I do not see that the abstract by Eliseev et al markedly changes this picture. Best, Ken ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA kcalde...@ciw.edu; kcalde...@stanford.edu http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab +1 650 704 7212; fax: +1 650 462 5968 On Mon, Apr 20, 2009 at 4:16 PM, John Nissen j...@cloudworld.co.uk wrote: ** *Some items from the EGU programme* ** *Cryosphere - how much longer?* This should be an interesting session: http://meetingorganizer.copernicus.org/EGU2009/oral_programme/142 Also on cryosphere is the session chaired by Peter Wadhams: http://meetingorganizer.copernicus.org/EGU2009/oral_programme/196 And some potentially interesting presentations here: http://meetingorganizer.copernicus.org/EGU2009/oral_programme/702 and here: http://meetingorganizer.copernicus.org/EGU2009/oral_programme/706 *Geoengineering, session CL27* There seems to have been a disappointing response for this session. However the session does include a poster presentation from Russians on SRM using stratospheric sulphur aerosols:
[geo] Re: a very simply way to lift sulfur
1. Space tethers are physics fun, but practical systems require unobtainium. No materials are close to being strong enough to make them interesting; indeed one can make an argument based on the strength of chemical bonds that no such material is possible. 2. Tethered balloons are interesting. There are, however, lots of engineering challenges in making a tether work at mid latitudes (in the jet) and in making a tether that works as a hose. 3. Aircraft are the default option. I am getting some work started with a high-altitude aircraft engineering company on the topic. For the lower and middle stratosphere this is likely to cheapest and most controllable option. -David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Albert Kallio Sent: March 23, 2009 8:34 AM To: agask...@nc.rr.com; Andrew Lockley Cc: Geoengineering FIPC Subject: [geo] Re: a very simply way to lift sulfur The idea of space tethers is to pull up cable all the way to orbit and then drive things to the geostationary orbit. I think it is far more complex idea to this. The throughput would have to be assessed correctly, the sharp attachment point might be the issue with hose-blimp combinations due to turbulence, just like tall buildings wave at winds the hose should be responding to the air. But when weather is turbulent, supercells forming and winds criss-crossing to all directions, then it would get entangled. But I would think that there are plenty of engineering solutions to keep things floating orderly and managing any entanglement and the correct trhoughput issue most surely. Rgs, albert From: agask...@nc.rr.com To: albert_kal...@hotmail.com; andrew.lock...@gmail.com CC: geoengineering@googlegroups.com Subject: [geo] Re: a very simply way to lift sulfur Date: Mon, 23 Mar 2009 10:21:40 -0400 Such a tube would collapse under its own weight before getting more than a few meters off the ground. Also, a very thin tube wouldn't carry much gas, so what's the point. Winds near the tropopause would cause most materials to break, including hoses attached to blimps. - Original Message - From: Albert Kallio mailto:albert_kal...@hotmail.com To: Andrew Lockley mailto:andrew.lock...@gmail.com ; agask...@nc.rr.com Cc: Geoengineering FIPC mailto:geoengineering@googlegroups.com Sent: Monday, March 23, 2009 9:30 AM Subject: [geo] Re: a very simply way to lift sulfur As per Andrews' suggestion below about nozzle up hydrogen, I think it can become turbulent and vortexes form to dissipate and dilute the gas. How about a very thin tubular plastic film that acts as a hose to stand upright when filled by compressed hydrogen - sulphur mixture. The correct throughput ratios (pressures, diameter and mixture) could be tested with short films and then the length of the film is increased gradually to the right target altitude. As hydrogen is buoyant and the pressure is slighly higher gas would keep more or less upright as long as there is gas fed into it at the rate it is seeping out from the other end, plus any leakage in the upward transmission in between (tube can deteriorate and leak). The diameter could be utilised to suit the flow. The hose would act like a long standing balloon, possibly snap in severe weather but these could be looked at and nylon reinforcement line perhaps attached to it. I would try with first very short plastic film, then adding more and more metres onto it. Ultimately, this should then go all the way up modifying the top for different conditions. Rgs, Albert Date: Sun, 22 Mar 2009 17:52:42 + Subject: [geo] Re: a very simply way to lift sulfur From: andrew.lock...@gmail.com To: agask...@nc.rr.com CC: geoengineering@googlegroups.com I think with correct design you could send up a large plume successfully into the stratosphere. High pressure gas should exit the container or nozzle at high speed, forming a very wide column of fast moving gas. Heating the gas would help also. This process is very similar to the way volcanos work. If you wanted to protect the ozone layer, then adding ozone to the mix as suggested should make a significant difference. I'm thinking of something on the scale of the gas storage towers you see in the UK, bursting open very suddenly. This would require no expensive balloons which yould turn to litter. As there was no equipment or envelope to lift, a lower concentration of H2 lifter would be needed. A 2009/3/22 Alvia Gaskill agask...@nc.rr.com No it
[geo] Re: Atmospheric 'Sunshade' Could Reduce Solar Power Generation
On Thu, 19 Mar 2009, David Keith wrote: I think this issue is grossly overhyped 1. It only matters for concentrating solar. It matters much more for concentrating solar, but proposals for many new systems emphasize concentrating solar, because it is more efficient. Even for regular photovoltaic, the reductioun in sunlight would reduce solar power. Concentrating solar is not necessarily more efficient. It may end up winning on capex, but it is far, far too early to call the winner. See our recent solar study from EST to give you a sense of the range of uncertainty judgment about the future cost declines in solar PV held by experts in PV development: www.ucalgary.ca/~keith/Other Energy.html http://www.ucalgary.ca/~keith/Other%20Energy.html (Paper #100). -D 2. In a case for we really were in a bad enough state to be geoengineering is not clear that the loss of solar output would be that big a deal when you really balance the overall costs and risks. Mitigation will need many different responses simultaneously, beginning now, and many more concentrated solar systems are being built now. If at some point we do geoeengineering with scattered sunlight, we will have to do that much more to compensate for the loss of solar energy. So why plan two incompatible solutions to global warming? Need to do the math here. Look at the model I presented in Copenhagen. I think we both view geo as something we do in a contingency where climate sensitivity turns out to be very high, not as a baseline plan. In that contingency, the GDP costs of climate damages are high. Compared to these costs the loss of a fraction of concentrating solar, which is itself a fraction of solar and even smaller fraction of primary energy would be a few % of the annualized mitigation costs, which under this scenario would be small compared to the damage costs. Are you suggesting that in a situation where climate damages were so severe that the benefits of geo outweighed the costs that one would not do geo just because of the loss of solar output? I just don't see an argument here. Please be more specific about what specific consequences for decision-making is entailed by the possible loss of solar power output under some geo schemes. 3. There are many geoengineering schemes that can avoid the forward scattering problem, such as various engineered particles in the upper atmosphere, or so it's by no means clear we would have this problem in any case. You say, this, but please provide the references for these many schemes. I know of theoretical speculation about making such particles, but no demonstration that they can be created with the proper characteristics on a massive scale nor that the fallout would be innocuous. We know a lot about sulfate aerosols from volcanic eruptions, their benefits and problems, but what do we know about these many other schemes? Of course there is no demonstration engineered particles can work. However, the physics that says you can make particles out of benign materials which do not have much forward scattering is old, simple and un-disputed. I don't think there's any doubt you could fabricate such particles and put them in the atmosphere. I have a paper under review that outlines a particular method. But even if 10's of nice papers were published and there was a small demonstration we would still, of course, not have a demonstration that such a method would work at scale and that we would understand all the side effects. The forthcoming Novim says a bit more about different kinds of particles and about a pathway for development and testing. Note that, while it's clear we know much more about sulfur we don't know for sure that sulfur particles of the relevant size can be efficiently maintained in the stratosphere, we also know many of the disadvantages of sulfur. It's far too early to really evaluate these options in a comparative way. That's why we need broad-based research program. -David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Nick Woolf Sent: March 17, 2009 5:30 PM To: r...@llnl.gov; geoengineering@googlegroups.com; climateintervent...@googlegroups.com Subject: [geo] Re: Atmospheric 'Sunshade' Could Reduce Solar Power Generation Dear All: The issue of the loss to solar concentrators is dependent on how much solar concentration is needed. Since silicon fails to match the cost of other power by a factor of 4, some higher concentration on it, e.g. by a factor 8 should do, provided that no more than half the cost is made up by auxiliary optics, steel etc. The angle of collection for an 8x concentrator is extremely wide, and would not be appreciably affected
[geo] Re: a very simply way to lift sulfur
I completely agree that the focus should be on thing works without producing too much acid rain or snow or other unanticipated negative effects. That's where my focus is and I think the focus of most research in the area. -D From: Eugene I. Gordon [mailto:euggor...@comcast.net] Sent: March 24, 2009 10:17 AM To: David Keith; 'Geoengineering FIPC' Subject: RE: [geo] Re: a very simply way to lift sulfur Why isn't the focus on whether the thing works without producing too much acid rain or snow or other unanticipated negative effects? If viability is proven then problem #2 is cost of lifting. I would suggest very strongly that problem #2 is solvable many different ways and I would not waste too much time on it at this point. Whatever, the cost of lifting in a practical implementation, having a proven technical approach eliminates the naysayers and moves the discussion onto a more practical level. Let us lift the technology before lifting the sulfur! From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of David Keith Sent: Tuesday, March 24, 2009 11:57 AM To: Geoengineering FIPC Subject: [geo] Re: a very simply way to lift sulfur 1. Space tethers are physics fun, but practical systems require unobtainium. No materials are close to being strong enough to make them interesting; indeed one can make an argument based on the strength of chemical bonds that no such material is possible. 2. Tethered balloons are interesting. There are, however, lots of engineering challenges in making a tether work at mid latitudes (in the jet) and in making a tether that works as a hose. 3. Aircraft are the default option. I am getting some work started with a high-altitude aircraft engineering company on the topic. For the lower and middle stratosphere this is likely to cheapest and most controllable option. -David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Albert Kallio Sent: March 23, 2009 8:34 AM To: agask...@nc.rr.com; Andrew Lockley Cc: Geoengineering FIPC Subject: [geo] Re: a very simply way to lift sulfur The idea of space tethers is to pull up cable all the way to orbit and then drive things to the geostationary orbit. I think it is far more complex idea to this. The throughput would have to be assessed correctly, the sharp attachment point might be the issue with hose-blimp combinations due to turbulence, just like tall buildings wave at winds the hose should be responding to the air. But when weather is turbulent, supercells forming and winds criss-crossing to all directions, then it would get entangled. But I would think that there are plenty of engineering solutions to keep things floating orderly and managing any entanglement and the correct trhoughput issue most surely. Rgs, albert From: agask...@nc.rr.com To: albert_kal...@hotmail.com; andrew.lock...@gmail.com CC: geoengineering@googlegroups.com Subject: [geo] Re: a very simply way to lift sulfur Date: Mon, 23 Mar 2009 10:21:40 -0400 Such a tube would collapse under its own weight before getting more than a few meters off the ground. Also, a very thin tube wouldn't carry much gas, so what's the point. Winds near the tropopause would cause most materials to break, including hoses attached to blimps. - Original Message - From: Albert Kallio mailto:albert_kal...@hotmail.com To: Andrew Lockley mailto:andrew.lock...@gmail.com ; agask...@nc.rr.com Cc: Geoengineering FIPC mailto:geoengineering@googlegroups.com Sent: Monday, March 23, 2009 9:30 AM Subject: [geo] Re: a very simply way to lift sulfur As per Andrews' suggestion below about nozzle up hydrogen, I think it can become turbulent and vortexes form to dissipate and dilute the gas. How about a very thin tubular plastic film that acts as a hose to stand upright when filled by compressed hydrogen - sulphur mixture. The correct throughput ratios (pressures, diameter and mixture) could be tested with short films and then the length of the film is increased gradually to the right target altitude. As hydrogen is buoyant and the pressure is slighly higher gas would keep more or less upright as long as there is gas fed into it at the rate it is seeping out from the other end, plus any leakage in the upward transmission in between (tube can deteriorate and leak). The diameter could be utilised to suit the flow. The hose would act like a long standing balloon, possibly snap in severe weather but these could be looked at and nylon reinforcement line perhaps attached to it. I would try with first very short plastic film, then adding more
[geo] Re: Atmospheric 'Sunshade' Could Reduce Solar Power Generation
I think this issue is grossly overhyped 1. It only matters for concentrating solar. 2. In a case for we really were in a bad enough state to be geoengineering is not clear that the loss of solar output would be that big a deal when you really balance the overall costs and risks. 3. There are many geoengineering schemes that can avoid the forward scattering problem, such as various engineered particles in the upper atmosphere, or so it's by no means clear we would have this problem in any case. -David From: geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] On Behalf Of Nick Woolf Sent: March 17, 2009 5:30 PM To: r...@llnl.gov; geoengineering@googlegroups.com; climateintervent...@googlegroups.com Subject: [geo] Re: Atmospheric 'Sunshade' Could Reduce Solar Power Generation Dear All: The issue of the loss to solar concentrators is dependent on how much solar concentration is needed. Since silicon fails to match the cost of other power by a factor of 4, some higher concentration on it, e.g. by a factor 8 should do, provided that no more than half the cost is made up by auxiliary optics, steel etc. The angle of collection for an 8x concentrator is extremely wide, and would not be appreciably affected by forward scattering into a 45 degree cone. Of course for those that want solar electricity to fail, any stick is good enough to beat a dog. Nick Woolf - Original Message - From: Greg Rau mailto:r...@llnl.gov To: geoengineering@googlegroups.com ; climateintervent...@googlegroups.com Sent: Tuesday, March 17, 2009 2:02 PM Subject: [geo] Atmospheric 'Sunshade' Could Reduce Solar Power Generation http:// www. sciencedaily.com/releases/2009/03/090311124022.htm http://%20www.%20sciencedaily.com/releases/2009/03/090311124022.htm See Web-Photo: The world's largest solar power facility, located near Kramer Junction, CA, consists of five Solar Electric Generating Stations and covers more than 1,000 acres. (Credit: Department of Energy/National Renewable Energy Laboratory) Atmospheric 'Sunshade' Could Reduce Solar Power Generation ScienceDaily (Mar. 16, 2009) - The concept of delaying global warming by adding particles into the upper atmosphere to cool the climate could unintentionally reduce peak electricity generated by large solar power plants by as much as one-fifth, according to a new NOAA study. Injecting particles into the stratosphere could have unintended consequences for one alternative energy source expected to play a role in the transition away from fossil fuels, said author Daniel Murphy, a scientist at NOAA's Earth System Research Laboratory in Boulder, Colorado. The Earth is heating up as fossil-fuel burning produces carbon dioxide, the primary heat-trapping gas responsible for man-made climate change. To counteract the effect, some geoengineering proposals are designed to slow global warming by shading the Earth from sunlight. Among the ideas being explored is injecting small particles into the upper atmosphere to produce a climate cooling similar to that of large volcanic eruptions, such as Mt. Pinatubo's in 1991. Airborne sulfur hovering in the stratosphere cooled the Earth for about two years following that eruption. Murphy found that particles in the stratosphere reduce the amount and change the nature of the sunlight that strikes the Earth. Though a fraction of the incoming sunlight bounces back to space (the cooling effect), a much larger amount becomes diffuse, or scattered, light. On average, for every watt of sunlight the particles reflect away from the Earth, another three watts of direct sunlight are converted to diffuse sunlight. Large power-generating solar plants that concentrate sunlight for maximum efficiency depend solely on direct sunlight and cannot use diffuse light. Murphy verified his calculations using long-term NOAA observations of direct and diffuse sunlight before and after the 1991 eruption. After the eruption of Mt. Pinatubo, peak power output of Solar Electric Generating Stations in California, the largest collective of solar power plants in the world, fell by up to 20 percent, even though the stratospheric particles from the eruption reduced total sunlight that year by less than 3 percent. The sensitivity of concentrating solar systems to stratospheric particles may seem surprising, said Murphy. But because these systems use only direct sunlight, increasing stratospheric particles has a disproportionately large effect on them. Nine Solar Electric Generating Stations operate in California and more are running or are under construction elsewhere in the world. In sunny locations such systems, which use curved mirrors or other
