I'm surprised Alan should neglect to cite studies other than his own, as climate responses to carbon aerosols in the atmosphere vary greatly. The recent literature is illustrative- a growing concern is the impact of black carbon from satellite and spacecraft launches, which may warm the upper atmosphere rather than cool it:
Journal of Geophysical Research: Atmospheres <https://agupubs.onlinelibrary.wiley.com/journal/21698996> 1June2022 The Climate and Ozone Impacts of Black Carbon Emissions From Global Rocket Launches Christopher M Maloney <https://agupubs.onlinelibrary.wiley.com/action/doSearch?ContribAuthorRaw=Maloney%2C+Christopher+M> , Robert W Portmann <https://agupubs.onlinelibrary.wiley.com/action/doSearch?ContribAuthorRaw=Portmann%2C+Robert+W> , Martin N Ross <https://agupubs.onlinelibrary.wiley.com/action/doSearch?ContribAuthorRaw=Ross%2C+Martin+N> , Karen H Rosenlof <https://agupubs.onlinelibrary.wiley.com/action/doSearch?ContribAuthorRaw=Rosenlof%2C+Karen+H> https://doi.org/10.1029/2021JD036373 Aerosol emissions from spaceflight activities play a small but increasing role in the background stratospheric aerosol population. Rockets used by the global launch industry emit black carbon (BC) particles directly into the stratosphere where they accumulate, absorb solar radiation, and warm the surrounding air. We model the chemical and dynamical response of the atmosphere to northern mid-latitude rocket BC emissions. We initially examine emissions at a rate of 10 Gg per year, which is an order of magnitude larger than current emissions, but consistent with extrapolations of space traffic growth several decades into the future. We also perform runs at 30 and 100 Gg per year in order to better delineate the atmosphere's response to rocket BC emissions. We show that a 10 Gg/yr rocket BC emission increases stratospheric temperatures by as much as 1.5 K in the stratosphere. Changes in global circulation also occur. For example, the annual subtropical jet wind speeds slow down by as much as 5 m/s, while a 10%–20% weakening of the overturning circulation occurs in the northern hemisphere during multiple seasons. Warming temperatures lead to a ozone reduction in the northern hemisphere by as much as 16 DU in some months. The climate response increases in a near linear fashion when looking at larger 30 and 100 Gg emission scenarios. Comparing the amplitude of the atmospheric response using different emission rates provides insight into stratospheric adjustment and feedback mechanisms. Our results show that the stratosphere is sensitive to relatively modest BC injections. On Tuesday, July 26, 2022 at 10:20:44 AM UTC-4 Alan Robock wrote: > Dear Gideon, > > A nuclear war would be orders of magnitude worse than any impacts of SAI > or termination. Soot from fires ignited by nuclear attacks on cities and > industrial areas would last for many years, and would overwhelm any impacts > from shorter lived sulfate aerosols. Of course the impacts depend on how > much soot, but a war between the US and Russia could produce a nuclear > winter. For more information on our work and the consequences of nuclear > war, please visit http://climate.envsci.rutgers.edu/nuclear/ > > Alan Robock > > Alan Robock, Distinguished Professor > Department of Environmental Sciences Phone: +1-848-932-5751 > <(848)%20932-5751> > Rutgers University E-mail: > [email protected] > 14 College Farm Road http://people.envsci.rutgers.edu/robock > New Brunswick, NJ 08901-8551 ☮ https://twitter.com/AlanRobock > > [image: Signature] > > > On 7/26/2022 10:03 AM, Gideon Futerman wrote: > > As part of the RESILIENCER Project, we are looking at low probability high > impact events and their relation to SRM. One important worry in this > regards becomes termination shock, most importantly what Baum (2013) calls > a "Double Catastrophe" where a global societal collapse caused by one > catastrophe then causes termination shock, another catastrophe, which may > convert the civilisational collapse into a risk of extinction. > > One such initial catastrophe may be nuclear war. Thus, the combination of > SRM and nuclear war may be a significant worry. As such, I am posing the > question to the google group: what would happen if SRM (either > stratospheric or tropospheric- or space based if you want to go there) was > terminated due to a nuclear war? What sort of effects would you expect to > see? Would the combination worsen the effects of nuclear war or help > ameliorate them? How would this differ between SRM types? > > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/geoengineering/8d0d8c0a-0f0d-440c-9bb5-f8641560e4a0n%40googlegroups.com > > <https://groups.google.com/d/msgid/geoengineering/8d0d8c0a-0f0d-440c-9bb5-f8641560e4a0n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/affd3889-c7c8-4a54-91c1-8d2373f806bdn%40googlegroups.com.
