Hi Andrew, this is not quite correct. In my paper with Pete we conclude that it should be relatively easy to build an SRM system that would be robust and resilient against all but the most biblical of catastrophes. This challenges the common assumption that terrorists or disgruntled states could force termination shock. But it doesn't mean that an SRM system would not be vulnerable to these potential threats if people did not choose to make the system robust and resilient. As such we agree with Andreas that management of the risk of termination shock must be a central consideration of any plan to use SRM, but we do think that this risk is lower than many commentators have assumed. Anyway our paper will be out in the next few weeks and we'll post it here, then you can see whether or not you agree with our analysis. Andy
On Saturday, February 24, 2018 at 1:37:00 AM UTC+1, Andrew Lockley wrote: > > Poster's note: others challenge these arguments. Parker and Irvine dispute > the vulnerability of solar geoengineering to anything less than eg a > nuclear war. Keith et al. suggest it can be temporarily deployed > > https://www.nature.com/articles/d41586-018-02203-x > > Solar engineering must take temperature debt into account > Andreas Oschlies > > - > > <https://twitter.com/intent/tweet?text=Solar+engineering+must+take+temperature+debt+into+account&url=https%3A%2F%2Fwww.nature.com%2Farticles%2Fd41586-018-02203-x> > > - > > <http://www.facebook.com/sharer.php?u=https%3A%2F%2Fwww.nature.com%2Farticles%2Fd41586-018-02203-x> > > - <javascript:> > > PDF version > <https://www.nature.com/magazine-assets/d41586-018-02203-x/d41586-018-02203-x.pdf> > > Solar geoengineering is a proposed method of climate engineering that aims > to reduce global warming using an artificial ‘sunscreen’ of aerosols in > Earth’s high atmosphere. As planning of the first field experiments gets > under way, any potential risks associated with the technology must be > transparently assessed and not downplayed or dismissed. One such risk of > solar geoengineering is its ‘temperature debt’ — the planetary heating that > would arise if maintenance of the artificial sunscreen was discontinued. > > Modelling suggests that most of the world’s population could benefit from > this temporary sunscreen, compared with the adverse effects of unabated > climate change (a questionable reference state, in my view). However, > models also reveal the alarming rise in temperatures that could occur if > the screen of short-lived aerosols should suddenly cease to function for > any reason in the presence of high concentrations of long-lived greenhouse > gases (see H. D. Matthews and K. Caldeira *Proc. Natl Acad. Sci. USA*104, > 9949–9954; > 2007 <http://dx.doi.org/10.1073/pnas.0700419104>). This rapid warming > would pose a severe risk to ecosystems and society. > > Even with the best planning to ensure steady operation of the technology, > its continuous safe functioning and maintenance cannot be guaranteed. Yet > it could take hundreds of years to safely phase out solar geoengineering > and achieve the same degree of cooling by reducing greenhouse-gas > concentrations. It is therefore imperative that, in the absence of a > fail-safe mode for solar geoengineering, the temperature debt is fully > accounted for in any assessments of this technology. > > Nature 554, 423 (2018) > doi: 10.1038/d41586-018-02203-x > -- 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
