It would be interesting to see if a local geoengineering scheme could be carried out using trop sulphur by varying fuel types.
Changing power station coals should be pretty easy as they are stockpiled. 'Heatwave coal' could be stored for use. Whether the air is already too dirty for it to matter would have to be calculated. My guess is that it would be effective, based on other papers on this list which considered reversing local pollution, showing a temp rise. One potential benefit is that trop aerosols could act as CCN, albeit largely in clean air. If that does work it could possibly induce a cloud deck and or rain, both of which would have locally beneficial temperature effects. Such a fuel switch is likely to be more publicly acceptable than deliberate spraying. As sulphur rich fuels are cheaper it could be described as a 'temporary easing of smog controls'. A On Jul 11, 2012 8:58 AM, "Ken Caldeira" <[email protected]> wrote: > Yes this is interesting and novel work. As Greg points out, it would be > very interesting to see how results scale with the altitude of injection. > > If I read their numbers correctly, they are injecting at on the order of > 1% of what might be needed for an offsetting of global 2xCO2. > > Does anybody have any sense of what the amounts injected mean in terms of > local health effects etc? > > > > > On Tue, Jul 10, 2012 at 8:21 PM, Gregory Benford <[email protected]>wrote: > >> Very interesting work. I wish it included the actual heights chosen to >> release aerosol (held constant, or varied with location? etc), the >> dispersion rates, and the granulation in cooling effect. >> >> Gregory Benford >> >> >> On Tue, Jul 10, 2012 at 10:09 AM, Josh Horton >> <[email protected]>wrote: >> >>> Hi all, >>> >>> Here is an abstract and link for an interesting manuscript on aerosol >>> injections to combat regional heatwaves, in this case California. It >>> touches on both regional schemes and the sometimes blurry line between >>> geoengineering and weather modification. >>> >>> Josh Horton >>> [email protected] >>> http://geoengineeringpolitics.blogspot.com/ >>> >>> >>> http://www.atmos.ucla.edu/~qli/publications/Bernstein_2012_ACPD.pdf >>> >>> Could aerosol emissions be used for regional heat wave mitigation? >>> >>> Abstract. Geoengineering applications by injection of sulfate >>> aerosols into the stratosphere are under consideration as >>> a measure of last resort to counter global warming. Here >>> adaptation to a potential regional-scale application to offset >>> 5 the impacts of heat waves is critically examined. The effect >>> of regional-scale sulfate aerosol emission over California >>> in each of two days of the July 2006 heat wave using the >>> Weather Research Forecast model with fully coupled chemistry >>> is used to quantify potential reductions in surface tem10 >>> perature as a function of emission rates in the lower stratosphere. >>> Over the range considered, afternoon temperature >>> reductions scale almost linearly with emissions. Local meteorological >>> factors yield geographical differences in surface >>> air temperature sensitivity. For emission rates of approx15 >>> imately 30 g mô€€€2 sô€€€1 over the region, temperature decreases >>> of around 7 C result during the middle part of the >>> day over the Central Valley, one of the hardest hit by the >>> heatwave. Regions more ventilated with oceanic air such as >>> Los Angeles have slightly smaller reductions. The length >>> 20 of the hottest part of the day is also reduced. Advection effects >>> on the aerosol cloud must be more carefully forecast for >>> smaller emission regions. Verification of the impacts could >>> be done via measurements of differences in reflected and surface >>> downward shortwave. Such regional geoengineering ap25 >>> plications with specific near-term target effects but smaller >>> cost and side effects could potentially provide a means of >>> testing larger scale applications. However, design trade-offs >>> differ from global applications and the size of the required >>> emissions and the necessity of emission close to the target >>> 30 region raise substantial concerns. The evaluation of this regional >>> scale application is thus consistent with global model >>> evaluations emphasizing that mitigation via reduction of fossil >>> fuels remains preferable to considering geoengineering >>> with sulfate aerosols. >>> >>> -- >>> 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. >>> >>> >> -- >> 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. >> > > -- > 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. > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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