Alan, While you may be correct that there is no hurry to spray salt into clouds, and there may be good reasons to delay testing nozzles in the field, guaranteeing "that you will be able to measure a signal and test all possible benefits and risks" should not be a pre-condition to all tests.
What if somebody is just trying to test whether a nozzle works, and there is absolutely no expectation of any harm (i.e., you are just spraying a little seawater into the air)? What dangers are you guarding against? The scale of environmental interference would be orders of magnitude smaller than produced by most ships burning high sulfur fuels. It is just silly to act as if these kind of experiments bear significant direct environmental risks. The motivations for delay are largely socio-political, related to the need for governance and control, and not because there is any expectation of significant risk or harm from the specific experiment. A more direct example is that Matthew Watson of Bristol is apparently planning to test the "hose to the sky idea", but apparently planning to pump water instead of sulfur. http://www.theengineer.co.uk/news/news-analysis/particle-injection-could-abate-climate-change/1003647.article Are we to say that nobody can pump water up a hose to a balloon without guaranteeing "that you will be able to measure a signal and test all possible benefits and risks"? I think we will be seeing a number of geoengineering tests proposed where there is no expectation of direct harm, and it will be very difficult to know how to regulate such experiments. Can nobody do any tests that involve pumping liquids to dirigibles? Or is it only if those tests are "geoengineering-related"? What if the funder is interested in commercial applications but the scientists are interested in geoengineering? What if the situation was reversed and the scientists have no geoengineering-related intent? And so on and so on. Part of keeping this conversation clear is to be clear about whether we are worried about (1) direct environmental risks from a particular experiment or we are worried about (2) socio-political risks stemming from an experiment [i.e., it might spur an inappropriate regulatory backlash] or (3) risks from possible future scale-up to which an experiment could potentially lead. For most of the small-scale tests being discussed today (e.g., testing nozzles, etc), the concerns fall into categories 2 and 3. For these experiments, we should not pretend that the experiment itself is likely to present real and significant direct environmental risk. Best, Ken ___________________________________________________ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 [email protected] http://dge.stanford.edu/labs/caldeiralab @kencaldeira On Sat, Oct 2, 2010 at 6:22 AM, Alan Robock <[email protected]>wrote: > Dear Mike, > > Thanks for the update on the models. This makes an even stronger case for > model experiments before we go out into the field. We really need to > understand what the potential reactions will be to cloud seeding so we can > guard against dangers and so that we can design field experiments that have > the potential to teach us about how the system works. I can see no argument > to hurry up and go spray salt into clouds now without a sound theoretical > background to guide where and for how long to spray, to guarantee that you > will be able to measure a signal and test all the potential benefits and > risks. Current arguments to go do this as soon as possible lack such > modeling backgrounds, that I know of. > > > Alan > > Alan Robock, Professor II (Distinguished Professor) > Editor, Reviews of Geophysics > Director, Meteorology Undergraduate Program > 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> > > > On 9/29/2010 12:13 PM, Mike MacCracken wrote: > > Yesterday I got to visit the NOAA lab in Boulder and, among other things, > get to see the simulations being done by their 15 km resolution icosahedral > grid simulation model with a finite volume numerical scheme. Other physics > is from the plug-in packages that are available and used in other GCMs. They > are running 10 day forecasts twice a day, and the results certainly look > quite good--better resolution really does help make things appear, at least > with respect to viewing of satellite movies of how the real world is > looking. And they are now getting to explore addition of the smaller scale > aspects not now represented in GCMs (at some point, the heat emissions from > energy use will become important for urban regions; reasonable up slope and > down slope flows; etc.) > > With respect to the proposed experiments, it is true that the weather is > chaotic (that is, changing the least significant bits in the initialization > of the model does over a couple of weeks lead to randomly correlated > weather), and that is what Alan is talking about for the weather time scales > (for climate scales, that requires longer simulations and experiments). But, > at the high resolutions that will soon be available (they are aiming in 1-2 > years for 4 km non-hydrostatic model, depending on timing of next generation > of graphical processors), my guess is that it is going to be possible to > explore the types of changes in weather that might result as a consequence > of the early cloud brightening field experiments. It will likely require an > ensemble set of simulations (things already being explored in simulations > with and without aerosols, etc.). > > As these models get more and more refined and seem to simulate more and more > phenomena that have previously been considered part of the variability [we > should really be saying unexplained instead of natural (even chaotic) > variability until we really get to better models], there will be more and > more capabilities to determine the significance of the changes in models, > and by thoughtful planning of the experiments, in the observations. > > Mike > > > On 9/29/10 5:16 AM, "Stephen Salter" <[email protected]> <[email protected]> > wrote: > > > Hi All > > Alan says that climate signals will be drowned out by chaotic climate > variations. Both the papers that I pointed to in my email of 24 > September were about picking up small signals from large, random > variations. The second paper suggests that a 20 year run of the > pseudo-random stimulus idea might be able to detect changes which are > one or two percent of the root mean square of the natural variation. I > am still hoping for suggestions. > > If I knew a bit more about chaos I would like to argue whether or not > the climate is chaotic or we are just ignorant about climate. The best > scientists and philosophers used to think that planetary motions, the > behaviour of chemical elements and the incidence of infectious illnesses > were chaotic. Believing that something is chaotic is an excellent way > of never discovering useful things about it. > > 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 195www.see.ed.ac.uk/~shs <http://www.see.ed.ac.uk/%7Eshs> > > > On 28/09/2010 20:44, Douglas MacMynowski wrote: > > Alan - I doubt there's any real disagreement here, but just a > clarification; climate variability/noise is irrelevant to the question > of whether some form of SRM can be tested, but of course critical to > the question of how long it would take to detect a signal. If the > goal is to estimate changes on a global scale, that will take decades > and significant forcing levels (we have a paper under review on this > subject that puts numbers on that trade-off). Other than the moral > hazard, I see no basic difference between testing this, and any other > experiment in any other field of engineering or science. Clearly with > one Earth, I agree with learning everything we can with computer > testing first, but if we ever did want to do this in full-scale, I'd > rather start small and learn something rather than just turning it on > and hoping for the best. > > doug > > On Sep 27, 11:44 am, Alan Robock<[email protected]> > <[email protected]> wrote: > > Dear Ken, > > I think you are being rather picky with words. In any case, I never > said it cannot be tested. I said it cannot be fully tested in a > real-world in situ experiment without full-scale implementation, because > the climate signal will be drowned out by chaotic climate variations and > because injecting into a pristine stratosphere cannot test injecting > into an existing cloud. Of course computers can be used for testing. > That is what I do, and I advocate much more of it. The statement below > refers to in situ experimentation. > > Alan > > Alan Robock, Professor II (Distinguished Professor) > Editor, Reviews of Geophysics > Director, Meteorology Undergraduate Program > 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> > > -- > 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]<geoengineering%[email protected]> > . > 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 [email protected]. 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