It is all about risk reduction. You cannot say how much risk we would be willing to accept from a climate intervention without first characterizing the risk of not intervening in climate.
If it is clear that a climate intervention would reduce risk (taking into account relevant distributional issues), then it would make sense to consider deployment, regardless of the levels of absolute risk. ___________________________________________________ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA [email protected]; [email protected] http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab +1 650 704 7212; fax: +1 650 462 5968 On Mon, May 11, 2009 at 3:46 PM, Dan Whaley <[email protected]> wrote: > John, > > This is really flimsy thinking. It springs from a WAG (wild-ass-guess) > type analysis of risk--"i.e. If it's not a lot, then it must be a little". > For a humorous take on this, watch Jon Stewart's daily show last week on the > LHC (Large Hadron Collider). I think it's about 19 minutes in. There is a > debate about whether there is a 50% risk of a "black hole" swallowing the > earth vs a zero percent chance. > > http://www.hulu.com/watch/70872/the-daily-show-with-jon-stewart-thu-apr-30-2009#s-p1-so-i0 > > <http://www.hulu.com/watch/70872/the-daily-show-with-jon-stewart-thu-apr-30-2> > > More importantly though, it's also really perilous thinking. The press > will pick this up as something akin to: "scientists planning experiment that > might kill 1 million people." etc etc. > > Unless you have some rigorous modeling behind your position, I'd suggest > refraining from these kind of hypothetical guesstimates. > > D > > > On Mon, May 11, 2009 at 3:11 PM, John Nissen <[email protected]> wrote: > >> >> Hi all, >> >> In the absense of any figures from you for monsoon failure risk, may I >> suggest a maximum probability of 1% of severe failure, causing the deaths >> of >> maximum 1 million people. If such a disaster occurred, the geoengineering >> would probably have to be stopped, even if the disaster was not 100% >> attributable to the geoengineering. So continued failure would not occur >> - >> at least not as result of geoengineering. Note that it would be continued >> failure for several years that could cause over a million deaths. >> >> Now, what is the next severest risk from aerosols, anyone? Or a worse >> risk? >> Ozone depletion? >> >> Cheers, >> >> John >> >> >> ----- Original Message ----- >> From: "John Nissen" <[email protected]> >> To: "Alvia Gaskill" <[email protected]>; <[email protected]>; >> <[email protected]> >> Cc: <[email protected]>; "Andrew Lockley" >> <[email protected]>; <[email protected]>; >> <[email protected]>; <[email protected]>; >> <[email protected]>; <[email protected]> >> Sent: Saturday, May 09, 2009 11:37 PM >> Subject: Re: [geo] Re: Balancing the pros and cons of geoengineering >> >> >> > Very good discussion. >> > >> > I'm trying to get a balance of pros (benefits B1-B7) and cons (specific >> > fears S1-S21). What I'd like out of our discussion is some kind of risk >> > assessment for the possible downside of a weaker monsoon, as this is >> > considered the biggest risk in the regional effects (S1). And we could >> > make this reasonably pessimistic, to be on the safe side - i.e. be >> > cautious with the application of geoengineering. On the other hand, we >> > might be able to reduce this risk, e.g. by neutralising sulphate >> aerosol; >> > if there's a good chance of this working, then we can factor that into >> the >> > calculation. Or the risk might be offset by a benefit in that region, >> e.g. >> > improved summer water supply from Himalayan glaciers? >> > >> > So, what kind of impact would a weaker monsoon (ISM) have on India? >> What >> > is the probability of stratospheric aerosols deployed in the Arctic >> would >> > produce a weaker monsoon? Can this risk be significantly countered? >> Can >> > it be significantly offset? >> > >> > Note that the risk on benefit side might be measured in terms of a risk, >> > without geoengineering, of millions or even billions of lives being lost >> > (especially if massive methane release adds several degrees of global >> > warming, B4). Alternatively we could measure in GDP lost - current >> global >> > GDP (aka GWP) is about $60 trillion I believe. >> > >> > Cheers, >> > >> > John >> > >> > >> > >> > ----- Original Message ----- >> > From: "Alvia Gaskill" <[email protected]> >> > To: <[email protected]>; <[email protected]> >> > Cc: <[email protected]>; "Andrew Lockley" >> > <[email protected]>; <[email protected]>; <[email protected]>; >> > <[email protected]>; <[email protected]>; >> > <[email protected]>; <[email protected]> >> > Sent: Saturday, May 09, 2009 4:50 PM >> > Subject: Re: [geo] Re: Balancing the pros and cons of geoengineering >> > >> > >> >> Stephen makes a good point that leads to a more general one. If there >> >> are precipitation reductions associated with sunlight blocking schemes, >> >> consideration should also be given to mitigating these, analogous to >> the >> >> medications given to patients with Type II diabetes to combat the side >> >> effects of the primary drug. >> >> >> >> This is an oversimplification, but the way summer monsoons work is that >> >> in the summer the land gets warmer than the ocean faster, creating a >> low >> >> pressure area and this causes on shore flow as air moves from high to >> low >> >> presssure. For some reason, Laki caused this to be muted. There were >> no >> >> aerosols from Laki over India and it has been suggested there was a >> >> teleconnected response (see the paper Stephen attached) although in >> paleo >> >> climate the authors say the effects were direct, but don't give >> >> specifics. In the case of Pinatubo, both the land and sea were cooled >> by >> >> the aerosol and the land simply didn't heat up fast enough to generate >> >> the on shore flow. >> >> >> >> If the Arctic only aerosol geoengineering does cause a reduction in the >> >> ISM (Indian Summer Monsoon as there are other monsoons that affect >> India, >> >> but this is the most important one), use of the cloud whitening to >> >> restore at least some of the temperature differential should be >> >> considered. Likewise, in a global aerosol scheme, with a global aerosol >> >> spread similar to that of Pinatubo, the cloud whitening could also be >> >> used to create a temperature differential, but at some point it becomes >> a >> >> race to the bottom, with the land temperature simply too cool to >> initiate >> >> the low pressure area. In this case, reducing the depth of the aerosol >> >> layer over the land may be the most effective way to restore the >> >> dynamics. >> >> >> >> I previously suggested using ammonia released from either planes or >> >> balloons to react with the sulfate aerosol and drop them out as >> ammonium >> >> sulfate. This idea as well as Stephen's could be applied to other >> >> locations such as the Amazon, Eastern China and Africa where models >> >> indicate unacceptable reductions in precipitation are a result of >> either >> >> aerosol geoengineering or global warming. Of course, the ammonia >> >> wouldn't be of any value in a global warming/no aerosol scenario. >> >> >> >> I said in one the earliest papers I wrote on geoengineering that >> >> eventually we were going to have to learn how to manipulate the climate >> >> to our advantage. That includes both gross scale and fine tuning. >> >> >> >> In a related issue, last year I posted a link from a group in the UK >> that >> >> was carrying out some 130 different models of aerosol geoengineering. >> It >> >> was a volunteer effort among universities. If they have done even a >> >> fraction of the modeling, this work should be taken into account in >> >> designing new studies such as Rutgers is proposing. Anyone have an >> >> update? >> >> >> >> You may recall also that we spent some time last year discussing the >> >> significance of the "little brown blotches" in absolute terms and now >> Ken >> >> also raises the issue of their resolution. >> >> >> >> http://en.wikipedia.org/wiki/Monsoon >> >> >> >> Monsoons are caused by the larger amplitude of the seasonal cycle of >> land >> >> temperature compared to that of nearby oceans. This differential >> warming >> >> happens because heat in the ocean is mixed vertically through a "mixed >> >> layer" that may be fifty meters deep, through the action of wind and >> >> buoyancy-generated turbulence, whereas the land surface conducts heat >> >> slowly, with the seasonal signal penetrating perhaps a meter or so. >> >> Additionally, the specific heat capacity of liquid water is >> significantly >> >> higher than that of most materials that make up land. Together, these >> >> factors mean that the heat capacity of the layer participating in the >> >> seasonal cycle is much larger over the oceans than over land, with the >> >> consequence that the air over the land warms faster and reaches a >> higher >> >> temperature than the air over the ocean.[11] Heating of the air over >> the >> >> land reduces the air's density, creating an area of low pressure. This >> >> produces a wind blowing toward the land, bringing moist near-surface >> air >> >> from over the ocean. Rainfall is caused by the moist ocean air being >> >> lifted upwards by mountains, surface heating, convergence at the >> surface, >> >> divergence aloft, or from storm-produced outflows at the surface. >> However >> >> the lifting occurs, the air cools due to expansion, which in turn >> >> produces condensation. >> >> >> >> In winter, the land cools off quickly, but the ocean retains heat >> longer. >> >> The cold air over the land creates a high pressure area which produces >> a >> >> breeze from land to ocean.[11] Monsoons are similar to sea and land >> >> breezes, a term usually referring to the localized, diurnal (daily) >> cycle >> >> of circulation near coastlines, but they are much larger in scale, >> >> stronger and seasonal.[12] >> >> >> >> >> >> >> >> ----- Original Message ----- >> >> From: "Stephen Salter" <[email protected]> >> >> To: <[email protected]> >> >> Cc: <[email protected]>; "Andrew Lockley" >> >> <[email protected]>; <[email protected]>; <[email protected]>; >> >> <[email protected]>; <[email protected]>; >> >> <[email protected]>; <[email protected]> >> >> Sent: Saturday, May 09, 2009 6:43 AM >> >> Subject: [geo] Re: Balancing the pros and cons of geoengineering >> >> >> >> >> >>> Hi All >> >>> >> >>> The attached paper by Zickfeld et al shows, in figure 2, what might >> >>> happen to the Indian Monsoon if we do nothing. Cooling the sea >> relative >> >>> to the land should move things in the opposite direction. >> >>> >> >>> Stephen >> >>> >> >>> Emeritus Professor of Engineering Design >> >>> School of Engineering and Electronics >> >>> University of Edinburgh >> >>> Mayfield Road >> >>> Edinburgh EH9 3JL >> >>> Scotland >> >>> tel +44 131 650 5704 >> >>> fax +44 131 650 5702 >> >>> Mobile 07795 203 195 >> >>> [email protected] >> >>> http://www.see.ed.ac.uk/~shs <http://www.see.ed.ac.uk/%7Eshs> >> >>> >> >>> >> >>> >> >>> Alan Robock wrote: >> >>>> Dear Ken, >> >>>> >> >>>> I agree. We need several models to do the same experiment so we can >> >>>> see >> >>>> how robust the ModelE results are. That is why we have proposed to >> the >> >>>> IPCC modeling groups to all do the same experiments so we can compare >> >>>> results. Nevertheless, observations after large volcanic eruptions, >> >>>> including 1783 Laki and 1991 Pinatubo, show exactly the same precip >> >>>> reductions as our calculations. >> >>>> >> >>>> Even if precip in the summer monsoon region goes down, how important >> is >> >>>> it for food production? It will be countered by increased CO2 and >> >>>> increased diffuse solar radiation, both of which should make plants >> >>>> grow >> >>>> more. We need people studying impacts of climate change on >> agriculture >> >>>> to take our scenarios and analyze them. >> >>>> >> >>>> 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<http://envsci.rutgers.edu/%7Erobock> >> >>>> >> >>>> >> >>>> >> >>>> Ken Caldeira wrote: >> >>>> >> >>>>> A few questions re claims about monsoons: >> >>>>> >> >>>>> 1. How well is the monsoon represented in the model's base state? Is >> >>>>> this a model whose predictions about the monsoon are to be trusted? >> >>>>> >> >>>>> 2. Since the believability of climate model results for any small >> >>>>> region based on one model simulation is low, for some reasonably >> >>>>> defined global metrics (e.g., rms error in temperature and precip, >> >>>>> averaged over land surface, cf. Caldeira and Wood 2008) is the >> amount >> >>>>> of mean climate change reduced by reasonable aerosol forcing? (I >> >>>>> conjecture yes.) >> >>>>> >> >>>>> Alan is interpreting as significant his little brown blotches in the >> >>>>> right side of Fig 7 in a model with 4 x 5 degree resolution (see >> >>>>> attachment). >> >>>>> >> >>>>> How does the GISS ModelE do in the monsoon region? If you look at >> Fig >> >>>>> 9 of Jiandong et al (attached), at least in cloud radiative forcing, >> >>>>> GISS ModelE is one of the worst IPCC AR4 models in the monsoon >> region. >> >>>>> >> >>>>> So, while Alan may ultimately be proven right, it is a little >> >>>>> premature to be implying that we know based on Alan's simulations >> how >> >>>>> these aerosol schemes will affect the Indian monsoon. >> >>>>> >> >>>>> If you look at Caldeira and Wood (2008), we find that idealized >> Arctic >> >>>>> solar reduction plus CO2, on average precipitation is increased >> >>>>> relative to the 1xCO2 world. >> >>>>> >> >>>>> >> >>>>> ___________________________________________________ >> >>>>> Ken Caldeira >> >>>>> >> >>>>> Carnegie Institution Dept of Global Ecology >> >>>>> 260 Panama Street, Stanford, CA 94305 USA >> >>>>> >> >>>>> [email protected] <mailto:[email protected]>; >> [email protected] >> >>>>> <mailto:[email protected]> >> >>>>> http://dge.stanford.edu/DGE/CIWDGE/labs/caldeiralab >> >>>>> +1 650 704 7212; fax: +1 650 462 5968 >> >>>>> >> >>>>> >> >>>>> >> >>>>> >> >>>> >> >>>> > >> >>>> >> >>>> >> >>> >> >>> >> >>> -- >> >>> >> >>> >> >>> >> >>> >> >>> The University of Edinburgh is a charitable body, registered in >> >>> Scotland, with registration number SC005336. >> >>> >> >>> >> >>> >>> >> >>> >> >> >> >> >> > >> > >> >> >> >> > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. 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