It seems that in all innocence we kept the planet's climate roughly stable for 8000 years [according to Ruddiman] by burning down forests, occasionally visited by plagues [sent by Gaia if we were going ahead too fast?]. But with the enlightenment came knowledge, of which eating the fruit has led to the passing of much wind, resulting in too much CO2 in the atmosphere. It does not seem there is any going back, so we need to keep on thinking how to get ourselves out of this fine mess [as Laurel would have said to Hardy, if not the other way round -- can never remember which was which].
A thought that has been bubbling in my head since reading the Zickfeld paper (thankyou Stephen) and maybe obvious to everyone else, is that, supposing we succeed in cooling the earth over the next few decades by lowering CO2 levels, through growing a lot of trees, extensive use of biochar, and combining bioenergy with CCS, then the terrestrial earth will be cooled faster than the oceanic earth and monsoon-like phenomena (watering the Amazon basin, and -- on a good year -- the Sahel, besides South Asia and East Africa) be inhibited worldwide. Thus we need to cool the ocean suface layers as well as the land. Stephen's ships are the one obvious utterly benign technology that has been proposed [if it works - surely time is ripe to try it out] but also Ocean Thermal power generation and Lovelock and Rapley's ocean pipes (with both the latter needing some cautions regarding possible ecological effects of bringing deep ocean creepy crawllies and suchlike to the surface). The beauty of the ocean surface cooling technologies is that they can be regionalised - e.g. to keep the monsoons going, to cool the coral reefs, to chill the Gulf Stream and hopefully preserve Arctic sea ice, while allowing North Pacific coasts, Patagonia, Tasmania and New Zealand to bask in warmer waters. No good for the WAIS of course, so maybe a bit of Crutzen's sulphur aerosols South of 60 deg. It may seem that some combination of reionalized albedo modification and carbon stock management is needed to get us out of this fine mess, meeting Harvard economist Martin Weitzman's call for "some semblance of a game plan for dealing realistically with what may be coming down the road". Of course with regionalisation comes politics. Maybe people around the North Atlantic seaboard would not take kindly to a chillier climate. Hmmm..... Cheers Peter ----- 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: Sunday, May 10, 2009 10:37 AM Subject: [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 >>> >>> >>> >>> 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 >>>> >>>> >>>> >>>> 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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