A new paper on SRM’s termination shock, written by Pete Irvine and me, is published today in Earth’s Future. You can read it here: http://onlinelibrary.wiley.com/doi/10.1002/2017EF000735/full Termination shock is often cited as one of the greatest risks from the development of SRM, but we noticed that most analysis is based on studies that model only worst-case scenarios. Typically commentators do not consider the factors that might cause – or avert – a sudden termination. In other words, people have been concluding on risk by looking only at vivid, worst-case impacts without any serious consideration of likelihood. In our paper we begin by characterising the physical dimensions of termination shock, then we look at the steps you’d have to go through for a driver (such as a natural disaster or political opposition) to lead to termination. We also consider where timely policy interventions might help. We conclude that: - If our assumptions about the costs and feasibility of SRM prove reasonable, it should be relatively easy to construct an SRM system that would be robust and resilient against all but the most biblical of global catastrophes. Some things that commentators have assumed could disable an SRM system (such as terrorist attacks or political demands) should not be able to do so unless the system were badly designed. - An SRM system could be interrupted for many months before temperatures began to rise, giving a buffer period in which it would be possible to redeploy. - Where multiple actors are capable of maintaining or redeploying SRM it cannot be terminated unilaterally. This is good for avoiding termination shock, not so good for lock-in. A consensus of capable parties is not required to start SRM, but might be needed to stop it once termination shock becomes possible. - People often say that say that once you start SRM you can’t stop it, but that’s just not accurate. A low level of SRM cooling could be stopped suddenly without fear of a large rise in temperatures and even a large degree of cooling could be phased out over a long period. Note that we do not find any reason to dismiss the risk of termination shock. If SRM is ever seriously considered for implementation then managing this risk should be a central concern. But we think that analysis of the risks of termination shock needs to consider likelihood alongside scale of impacts and we hope that our paper provides a foundation for this discussion. Andy -- 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 geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to email@example.com. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.