Thanks Ken
The tart conclusion is amusing: Conclusion Unfortunately, most proponents of schemes to abate the smog by meteorological modification consider that they have done their share in coming forward with the general ideas, and that it becomes the duty of the county Air Pollution Control District or the private Air Pollution Foundation to work out details and conduct all necessary computations and experimental tests to demonstrate whether or not they are feasible and workable. When it is suggested that the proponents should carry out some feasibility computations on their own to see whether their ideas deserve serious consideration, they frequently reply with the charge that the "vested interests" have "negative attitudes" in their attack on the problem. Such negative attitudes as exist in this matter are based on familiarity with the situation and repeated computations of the type given here. Having examined many proposals, one is naturally reluctant to spend time on detailed study of another variant. Only a completely new and unique approach to weather modification could have any hope of success in eliminating or ameliorating smog. Until such a unique approach has been demonstrated to be effective, it is reasonable for the agencies concerned with the solution of the problem to devote their undivided efforts to the detection and control of the sources of the pollutants responsible for the obnoxious and deleterious effects of smog. From: [email protected] [mailto:[email protected]] On Behalf Of Ken Caldeira Sent: Thursday, April 14, 2011 2:20 PM To: Hawkins, Dave Cc: [email protected]; [email protected] Subject: Re: [geo] Re: paper on altitude dependence of climate forcing and response from black carbon aerosols For your reading pleasure, attached is a shrunk version of the Neiburger paper referred to by Mike MacCracken. http://www.sciencemag.org/content/126/3275 On Thu, Apr 14, 2011 at 10:18 AM, Hawkins, Dave <[email protected]> wrote: Fascinating, Mike. Do you recall whether the advocates for these approaches in the late 50s rationalized them as needed because of a view that society would never pursue serious mitigation? David From: Mike MacCracken [mailto:[email protected]] Sent: Thursday, April 14, 2011 01:00 PM To: Geoengineering <[email protected]> Subject: Re: [geo] Re: paper on altitude dependence of climate forcing and response from black carbon aerosols One of the potential dissertation topics suggested to me in late 1965 or early 1966 by Dr. Edward Teller, who had been a leader in forming the Department of Applied Science of the University of California Davis where I was a graduate student, was to explore the potential for dispersing Los Angeles smog by depositing stripes of black carbon from airplanes at just the right interval to excite waves in the boundary of the mixed layer and the inversion layer. I chose not to pursue this, but in doing a bit of research on the idea, I read a fascinating paper by UCLA meteorology professor Morris Neiburger in Science in 1957 (see Neiburger, M, 1957, "Weather Modification and Smog," Science, Vol. 126, No. 3275 4 October 1957, pages 637-645-file was too large to attach ) that was written to discount a number of other hypotheses for getting rid of LA smog. The LA leaders had several years earlier decided not to provide several million dollars to Dr. Irving Krick who claimed he had a secret approach for doing this that he would not, and I think never did, reveal. (Krick was a professor at CalTech, as I recall, known best for asserting that he could make long range weather forecasts based on sunspot and related solar cycles, a technique demonstrated, as I understand it, by his weather prediction on D-Day.) In any case, there were quite a number of ideas for regional scale modifications of the environment back in those days. In the end, success has come from reducing emissions. [Incidentally, for my dissertation project, I chose another of Teller's suggestions, namely to convert the first global, moist, atmospheric GCM (constructed by Dr. Chuck Leith) into a latitude-vertical (so 2-D) global climate model to evaluate proposed hypotheses for explaining glacial cycling. At the time, Hayes and colleagues had not published their paper finding Milankovitch-driven variations in ocean sediments, so quite a number of other hypotheses were being discussed, including Ewing and Donn's Arctic cycling hypothesis (published in Science in the 1950s), which was the main one I tested, and discounted.] Mike MacCracken ****** On 4/14/11 12:17 PM, "Ken Caldeira" <[email protected]> wrote: Thanks to Oliver Morton for pointing out the attached paper from 1976, which may be of historical interest to readers of this group. On Wed, Apr 13, 2011 at 6:12 PM, Ken Caldeira <[email protected]> wrote: Dependence of climate forcing and response on the altitude of black carbon aerosols George A. Ban-Weiss1 , Long Cao1, G. Bala2 and Ken Caldeira1 Abstract Black carbon aerosols absorb solar radiation and decrease planetary albedo, and thus can contribute to climate warming. In this paper, the dependence of equilibrium climate response on the altitude of black carbon is explored using an atmospheric general circulation model coupled to a mixed layer ocean model. The simulations model aerosol direct and semi-direct effects, but not indirect effects. Aerosol concentrations are prescribed and not interactive. It is shown that climate response of black carbon is highly dependent on the altitude of the aerosol. As the altitude of black carbon increases, surface temperatures decrease; black carbon near the surface causes surface warming, whereas black carbon near the tropopause and in the stratosphere causes surface cooling. This cooling occurs despite increasing planetary absorption of sunlight (i.e. decreasing planetary albedo). We find that the trend in surface air temperature response versus the altitude of black carbon is consistent with our calculations of radiative forcing after the troposphere, stratosphere, and land surface have undergone rapid adjustment, calculated as "regressed" radiative forcing. The variation in climate response from black carbon at different altitudes occurs largely from different fast climate responses; temperature dependent feedbacks are not statistically distinguishable. Impacts of black carbon at various altitudes on the hydrological cycle are also discussed; black carbon in the lowest atmospheric layer increases precipitation despite reductions in solar radiation reaching the surface, whereas black carbon at higher altitudes decreases precipitation. http://www.springerlink.com/content/98480557727889h8/ Ban-Weiss, G., et al, Climate Dynamics, 20011 ___________________________________________________ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 <tel:%2B1%20650%20704%207212> <tel:%2B1%20650%20704%207212> [email protected] http://dge.stanford.edu/labs/caldeiralab @kencaldeira -- 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] <mailto: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]. To unsubscribe from this group, send email to [email protected] <mailto: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]. 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.
