Hi Andrew,
I personally don’t see this as a problem (and I’ve worked a bit with Wake on question). The direct costs of getting stuff to the stratosphere are not going to be the long-term barrier to deployment (and might not even be the biggest costs of deployment, assuming one needs to build more satellite observational capability, and ignoring the question of compensation/liability for perceived harms). What it does mean is that there is no instant-response capability (with aircraft, at least); one would need at least 3 years and a pile of $$ (few billion more likely) to develop an aircraft between a decision to deploy and the first aircraft (and more time before generating serious radiative forcing). This guarantees a bit of built-in caution both in starting, and in ramping up any deployment. Depending on one’s perspective, that could either be a problem or a benefit; I happen to lean to the latter category with the belief that the benefit of built-in caution outweighs the risks of not having capability for an instant response, though I understand that others may disagree with me on that. Note that your options (A) and (B) are effectively identical. Probably cheaper to start with a new fuselage if you’re going to re-wing and re-engine. Note also that Wake’s conclusion from talking to the aircraft manufacturers is that there is no problem with the mission statement; it is easy to achieve, it’s just that no-one has needed to do this before and so no-one has built an aircraft that can do it. That is pretty important to know. Also important is the estimate that a new aircraft would take ~3 years from putting the money down to having the first one (this is a lot simpler than a 787). If that number was 10 years, I would agree that it was a big problem… doug From: geoengineering@googlegroups.com <mailto:geoengineering@googlegroups.com> [mailto:geoengineering@googlegroups.com] On Behalf Of Andrew Lockley Sent: Sunday, October 15, 2017 7:20 PM To: geoengineering <geoengineering@googlegroups.com <mailto:geoengineering@googlegroups.com> > Subject: [geo] Engineering drama, post CEC >From what I gather, it seems we have a bit of engineering drama. Apparently, >you can't just swap aircraft engines and do SRM, because the wings aren't >right on any aircraft with even a vaguely adequate payload. This is A Problem. We've either got to A) engineer a new aircraft, like the Delft team did (with a $100m expected development cost) B) work out a way to make new wings for an existing jet (not simple) C) come up with something else If we assume it's C, then there's quite a lot decent new hardware around. One choice is Blue Origin/Space X kit. Does anyone know how that would fare in an up-and-down flight path? I know Blue Origin did that before. Payload should be manageable, but I'm not sure how costs are coming down. Another alternative is one of the hybrid concepts. I got a flea in my ear for mentioning BAE systems hybrid engines before. However, their power in thin air may make them suitable for geoengineering use - either as zoom climbers or cruise. I know that current thinking is to condense H2SO4 directly, but I guess with any kind of zoom climb, you're pretty much stuck dumping bulk SO2 and crossing your fingers it doesn't all coagulate to baseball-size and drop out! Would be great to hear from people on the list. (Personally, my concern is that our best option for accessing the stratosphere at the current rate of engineering might be to make a large pile of climate engineering governance papers, and walk up that carrying gas tanks! There will soon be enough of them ;) ) Andrew -- 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 <mailto:geoengineering+unsubscr...@googlegroups.com> . To post to this group, send email to geoengineering@googlegroups.com <mailto:geoengineering@googlegroups.com> . Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout. -- 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 geoengineering@googlegroups.com. Visit this group at https://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
