Chris, I'm sending a few thoughts on your recent paper to you and to the GE list, as I'm interested to hear opinions on your (open access) paper http://rsta.royalsocietypublishing.org/content/370/1974/4263.full
It's always good to hear about the detailed engineering of delivery systems, but from my initial reading of the work, there are a number of issues which strike me as immediate points of concern (in no particular order). 1) Use of possibly outdated models of injection latitudes and longitudes. If I understand correctly, you suggest a longitude dispersed system, and a latitude-concentrated one. This appears to contradict other authors' arguments (e.g. Heckendorn, 2009; MacCracken 2012) which seemingly suggest a regime broadly opposite to this paper's. 2) It seems strange to offer development times for aircraft the same as for balloons, when one exists and the other doesn't. Even more surprising when the aircraft currently exist in numbers which may be sufficient to approximately do the job (as Alvia discussed a while ago on this list). You also suggest that naval guns will take twice as long to develop as balloons. Surely the existence of these guns, and the production of similar guns in WWII, suggests a shorter timescale than you suggest? 3) You reference Blackstock (2009), which from memory suggest a far lower number of guns. Why are your numbers so much higher? Are you counting barrels or guns? 4) You seem to offer cost comparisons for systems that have perhaps not been optimized from an engineering perspective. Surely costs can sometimes hinge on issues identifiable only with very detailed study, similar to the one you set out for balloons. I'm left wondering whether any potential difference in the reliability of the various estimates could have been further stressed. 5) You offer very specific development timescales for long-term technology development projects. I think suggesting a 50 year development horizon for a technology is maybe a bridge too far. Perhaps this is hair-splitting, but I'd prefer to see 'can't be estimated' or 'beyond the horizon', rather than a specific-sounding but rather speculative '50 years'. It's good to have some hard engineering to debate. It would be great to hear your views, and others', on this interesting paper. Hopefully you'll be able to demolish a lot of my points, because it would be great to have such a clear steer on the costs as your paper seems to suggest. I look forward to your response. A -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
