It takes one to know one. ----- Original Message ----- From: "David Lewis" <jrandomwin...@gmail.com> To: geoengineering@googlegroups.com Sent: Saturday, December 8, 2012 6:47:50 PM Subject: [geo] At his AGU Tyndall Lecture: Raymond Pierrehumbert calls SRM geoengineering ideas "crazy", and "barking mad"
AND, he added: "the modelling technology is not even up to doing this adequately despite what some aggressive proponents of geoengineering say ". Raymond made his comments on geoengineering during the Q&A after his talk. The full text of his geoengineering remarks, which occur starting around minute 54 and 50 seconds of the AGU 2012 Tyndall Lecture which streams from that link, follow: ""I see lots [ of geoengineering ideas ] that are feasible but they all terrify me. Let me clarify a bit. Some people refer to schemes for taking CO2 out of the atmosphere, or sequestering CO2 as a form of geoengineering. Those I find relatively benign because they [ aim to ] put the climate system back in the state that it was in before we started to mess with it. The feasible geoengineering things, feasible - technologically feasible - things, that scare me terribly, are the crazy ideas to make artificial volcanoes and put sulphate aerosols into the stratosphere. And the reason I think those are barking mad is that CO2 will continue influencing the climate out for 10,000 years. You have to renew the aerosol forcing every two years or so. So you are assuming that somehow, society will stay together for the next 10,000 years and be able to jam up these extra aerosols, every two years or so... longer than there have been human civilizations practically. And if you ever stop then the aerosols go away in a couple of years and then you are hit with the full force of global warming in a time scale that is determined just by the ocean relaxation time. Unfortunately I think these sulphate aerosol injections are probably economically feasible. You don't have to inject too much up there but it puts the world in a state that I call the Damocles World. Its like the sword of Damocles which is the radiative forcing of CO2 just waiting to clobber you any time someone stops putting up these aerosols. And in addition we don't actually know enough about aerosol formation and about response of models to aerosols to begin doing this kind of fine tuning to even figure out how much we should put up there. There's some very good work by Leslie Gray at Oxford that shows how actually the modelling technology is not even up to doing this adequately despite what some aggressive proponents of geoengineering say". -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To view this discussion on the web visit https://groups.google.com/d/msg/geoengineering/-/5fhWCqZywkwJ . To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
