It's essential to consider the 'unmodified case'. Whatever 'damage' geoeng does has to be weighed against the damage that would occur from unfettered global warming to the Arctic region. The plight of the Polar bear is the poster child for global warming, which makes my point in a very clear way. A
2009/5/8 <[email protected]> > > John: > > You strike the nub of it: > > "Alan claims that the aerosols would not be confined to the polar > region. But doesn't this depend on: the timing range of the release of > precursor, the height range in the stratosphere, and the latitude > range? Suppose that the release is in spring such that most of the > aerosol has gone by the winter? Has any modelling been done on this > and other various possibilities?" > > This is what simulations are for, at first, but experiments must > follow. > > Also, what's the magnitude of the monsoon change, and its > uncertainties? Further, as I pointed out to Alan, the monsoon is not a > totally positive phenomenon -- there's flooding, crop damage, and loss > of life. I've been through some and they are indeed damaging. Soall > this needs to be studied in detail BEFORE we confront the truly hard > issue: how to trade off lesser rainfall against the Arctic dangers. > > Gregory Benford > > -----Original Message----- > From: John Nissen <[email protected]> > To: John Nissen <[email protected]>; geoengineering > <[email protected]> > Cc: [email protected]; Sam Carana <[email protected]>; > Ken Caldeira <[email protected]>; Peter Wadhams > <[email protected]> > Sent: Fri, 8 May 2009 3:09 pm > Subject: [geo] Re: Balancing the pros and cons of geoengineering > > Hi again, > > I am getting a lot of support for concentrating on > using stratospheric aerosols to save the Arctic sea ice, as a > > most urgent application for geoengineering. > > To me, perhaps the biggest specific danger is Alan > Robock's first, so I'd like to start the discussion on this: > > > S1. Could have adverse effect on some > regional climate(s) and ecosystem(s) [4] > > > where [4] is from Robock et al. > ---- > Regional Climate Responses to > Geoengineering with Tropical and Arctic SO2 Injections > > [quote] The safety and efficacy of the > recent suggestion of injection of sulfate aerosols into the Arctic > stratosphere > to prevent sea ice and Greenland from melting while avoiding adverse > effects on > the biosphere at lower latitudes [Lane et al., 2007] are not supported > by > our results. While Arctic temperature could be controlled, and sea ice > melting > could be reversed, there would still be large consequences for the > summer > monsoons, since the aerosols would not be confined to the polar region. > > ---- > > Alan claims that the aerosols would not > be confined to the polar region. But doesn't this depend on: the > timing > range of the release of precursor, the height range in the > stratosphere, and the > latitude range? Suppose that the release is in spring such that most > of the aerosol has gone by the winter? Has any modelling been done on > this > and other various possibilities? > > Cheers, > > John > > > > ----- Original Message ----- > From: > John Nissen > > =2 > 0 To: geoengineering > Cc: [email protected] > ; Sam > Carana ; Ken Caldeira ; Peter Wadhams > Sent: Thursday, May 07, 2009 10:38 > PM > Subject: Re: Balancing the pros and cons > of geoengineering > > > > Hi all, > > I'm restricting this analysis to geoengineering > with stratospheric aerosols to save the Arctic sea ice. I've not > received any additions to the list of pros and cons I posted on 29th > April. > > Some points have been discussed, mostly on 29th > April also: > > S11. Cannot stop quickly > William Fulkerson said that the > stratospheric aerosol technique is effectively "reversible". I > discussed > this point, suggesting the technique might be employed in spring, > such that > most aerosol would be gone by the following winter. > > G2. Making a hash of things > Stephen Salter argued that we don't often make a > complete hash of things - it's just that hashes are more newsworthy > than > successes. Good research is a safeguard. > > G1-G11 General objections to > geoengineering > Eugene Gordon suggested small-scale experiments > would not fall foul of any of these general objections. However, > Alan > Robock pointed out the difficulty of carrying out such experiments to > get > measurable results, without going full-scale. Alvia Gaskill > begged > to > differ, and there was a discussion of layers in the stratosphere. I > wrote to Prof Hansen asking for NASA help for experimentation (but no > reply > received). > > S10 If stop deployment, global warming will > spring back > Jim Thomas is worried by the effect of stopping > deployment, leading to rapid warming. John Gorman said that the > temperature would only rise to what you would have had without the > geoengineering - there would be no overshoot and no lasting effect. > (I > don't think it would even rise that much. It would simply rise as > fast as > forced by the current CO2e level above pre-industrial, other things > being > equal. Of course the CO2e level may have gone up considerably while > the > geoengineering was being applied, so there will be a jump in the RATE > of > temperature increase, as you'd expect, but no inertial or > coiled-spring > effect. Is that right, Ken?) > > G3 The moral hazard > This has been dismissed - as being the same > argument used against adaptation! The Greenpeace position on this > [1] > was heavily criticised in the DIUS report [2]. > > I suggest that the moral hazard has to be > discounted in balancing the risks, as it is impossible to quantify. > Likewise all the other general fears in G1-11. > > For the time bei > ng I suggest we ignore the > concerns of people who benefit from a warmer Arctic: CI-C3. > > Thus we should concentrate on B1-B7 and > S1-S21. > > The benefits can be costed in terms of what > happens if the sea ice disappears. Against this are the risks of > undesirable effects of the geoengineering - the downsides. For > obtaining a balance of risks, we need to: > > * calculate probability of success to halt Arctic > warming and sea ice retreat; > * estimate each benefit - as a cost > of NOT doing the geoengineering (e.g. losing an ecosystem); > * for each of these costs, multiply by > probability of it happening if the sea ice disappears; > * sum the above risks to be averted; > * multiply by the probability of success to obtain overall benefit; > * calculate probability of each > downside; > * estimate the cost of each > downside; > * multiply probability and cost to obtain risk > from doing the geoengineering; > * sum the downside risks to obtain total downside > risk; > * compare the > overall benefit with the total downside risk. > > Is that a fair approach? > > As a refinement, we can vary the risk of > geoengineering according to when we start deployment - which will > vary > according to when the Arctic sea ice first disappears. So we add the > time dimension. > > > > Cheers, > > John > > > [1] See David Santillo answer to > Q39: > > http://www.publications.parliament.uk/pa/cm200708/cmselect/cmdius/uc1064 > -i/uc106402.htm > > [2] DIUS report - geoengineering > section: > > > http://www.publications.parliament.uk/pa/cm200708/cmselect/cmdius/uc1064-i/uc106402.htm > > > > ----- Original Message ----- > From: > John > Nissen > To: geoengineering > Cc: [email protected] > > Sent: Wednesday, April 29, 2009 3:34 > PM > Subject: Balancing the pros and cons of > geoengineering > > > > Hi all, > > Alan Robock has said: > > "Whether we should use geoengineering as a temporary measure to > avoid > the most serious consequences of global warming requires a detailed > evaluation of the benefits, costs, and dangers of different > options." > > As you may already know, I am keen for rapid > development and deployment of SRM (solar radiation management) in > the > Arctic, with some benefits (if successful): > > B1. Save the Arctic sea ice and > associated ecosystem. > B2. Slow (and preferably halt) > Arctic warming. > B3. Reduce discharge of CO2 and methane, > =2 > 0 contributing to global warming and ocean acidification. > B4. Reduce risk of massive methane > discharge, sufficient to add several degrees of global > warming. > B5. Slow the rise in sea level from > Greenland glaciers. > B6. Reduce risk of Greenland ice sheet > destabilisation, and associated 6 metres of sea level rise. > B7. Develop the SRM techniques to use at > other latitudes. > > B4 amounts to a reduction in the risk of such > catastrophic global warming that human civilisation could not > survive. > > Against this we have the concerns of those > who currently benefit from a warmer Arctic: > > C1. Oil and mining industries, > prospecting in the Arctic region. > C2. Traders who use the North-West > passage. > C3. Greenlanders and others who may > prefer a warmer climate (cf. Inuit, who are having their way of > life > destroyed). > > > I think we should try to counter people's > natural fears about SRM geoengineering, especially stratospheric > sulfur > aerosols. What are the most frequent objections? One often > reads that the remedy (geoengineering) may be worse than the > disease > (global warming). We need to present a balanced pic > ture. > > General fears: > > G1. Geoengineering is interfering with > nature. (I heard that fear only this morning.) > G2. We've made such a hash of > interventions in the past, we're bound to make a hash of > geoengineering. > G3. Moral hazard - geoengineering is a > licence to continue CO2 pollution. > G4. Geoengineering is being offered as a > silver bullet, which it cannot be. > G5. You'll need international agreement - > and that will be even more difficult to get than agreement on > emissions > reduction. > G6. Too expensive - we always > underestimate. > G7. Too cheap, so anybody could do > it. > G8. It will not work. (We heard at > the DIUS hearing "if emissions reduction doesn't work, why should > geoengineering work") > G9. It will work - but you might overdo > it by mistake, leading to an ice age. > G10. High risk of "unknown unknowns" > turning out to be disastrous side-effects. > G11. Our understanding is too limited. > To quote the "Climate Safety > report": > > ".. even with the extraordinary advances in > climate science to date, our understanding of it has not developed > to such a > point as to allow20confidence that deploying direct cooling > techniques would > not cause more harm than good." [1] > > > Specific fears of stratospheric aerosols (from > Robock [2]): > > S1. Could have adverse effect on some > regional climate(s) and ecosystem(s) [4] > S2. Doesn't help with ocean > acidification. > S3. Ozone depletion. > S4. Effect on plants (but more diffuse > light has positive benefit?) > S5. Acid rain (noting that Alan Robock > has withdrawn this particular objection) > S6. Effect on cirrus clouds. > S7. Disappearance of blue skies (and > appearance of red sunsets?) could have negative psychological > impact. > S8. Less sun for solar > power. > S9. Environment impact of implementation > (e.g. if put sulfur in jetliners fuel). > S10. If > stop, previously suppressed global warming will spring back to hit > you. > S11. Cannot stop quickly enough, if you > did need to. > S12. Human error, with means of delivery, > causing dreadful accident. > S13. Moral hazard = G3. > S14. Cost = G6 > S15. Commercial control of > technology > S16. Military use of > technology > S17. Conflict with current > 20 treaties > S18. Control of the thermostat > S19. Questions of moral > authority > S20. Unexpected consequences = > G10. > > Alan has since withdrawn objections on acid > rain, S5, and cost, S14, but added a new one [3]: > > S21. Ruin astronomical observations > > > Do we have any more benefits, concerns, general fears or specific > fears > to add to these lists? > > Cheers, > > John > > > [1] http://climatesafety.org/wp-content/uploads/climatesafety.pdf > > [2] http://www.thebulletin.org/files/064002006_0.pdf. > Also see [3]. > > [3] Email from Alan Robock to the > geoengineering and climate intervention groups on 9th > April: > > ---- > > Dear All, > > As some of you know, I published a paper last > year: > > Robock, Alan, 2008: 20 reasons why geoengineering may be > a bad idea. > Bull. Atomic Scientists, 64, No. 2, 14-18, 59, > doi:10.2968/064002006. > > http://climate.envsci.rutgers.edu/pdf/20Reasons.pdf > > which > also produced a roundtable discussion: > > > http://www.thebulletin.org/web-edition/roundtables/has-the-time-come-geoengineering > > Since > then, I have been evaluating these rea > sons and two of them seem to > not > be of concern, excess acid deposition and cost. Our two papers on > > these results, now under review, are: > > Kravitz, Ben, Alan Robock, > Luke Oman, Georgiy Stenchikov, and Allison B. > Marquardt, 2009: Sulfuric > acid deposition from stratospheric > geoengineering with sulfate > aerosols. Submitted to J. Geophys. Res. > > http://climate.envsci.rutgers.edu/pdf/AcidDepositionJGRsubmitted.pdf > > Robock, > Alan, Allison B. Marquardt, Ben Kravitz, and Georgiy Stenchikov, > > 2009: The practicality of geoengineering. Submitted to > Geophys. Res. > Lett. > > http://climate.envsci.rutgers.edu/pdf/practicality8NoFig3.pdf > > But > I have also been giving talks on the subject and two days ago a > member > of an audience suggested another reason why geoengineering (with > > stratospheric aerosols) may be a bad idea: > > It would ruin > Earth-based optical astronomy! > > With the tremendous investment in > equipment, and mountain-top > observatories to get above most of the junk > in the atmosphere, not to > mention sophisticated signal processing > algorithms to remove the > remaining atmospheric influence, how could > astronomers stay silent and > allow permanent clouds that would block > their seeing? > > 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: [email protected] > New Brunswick, NJ > 08901-8551 USA http://envsci.rutgers.edu/~robock > > ---- > > [4] Robock et al. > > Regional Climate Responses > to Geoengineering with Tropical and Arctic SO2 > Injections > > [quote] The safety and efficacy of > the recent suggestion of injection of sulfate aerosols into the > Arctic > stratosphere to prevent sea ice and Greenland from melting while > avoiding > adverse effects on the biosphere at lower latitudes [Lane et al., > 2007] are not supported by our results. While Arctic temperature > could be > controlled, and sea ice melting could be reversed, there would > still be > large consequences for the summer monsoons, since the aerosols > would not be > confined to the polar region. > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
