I think there have been two main reasons for focus on sulfur, at least for the stratosphere:
1. It can be released as a gas (SO2 or H2S) that can then oxidize to form particles of approximately the right size, greatly reducing problems of dispersion upon release. 2. Volcanoes did it and it worked. We may be able to be about as intelligent as a volcano. _______________ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 [email protected] http://dge.stanford.edu/labs/caldeiralab @kencaldeira *YouTube:* <http://www.youtube.com/watch?v=a9LaYCbYCxo>Climate change and the transition from coal to low-carbon electricity<http://www.youtube.com/watch?v=a9LaYCbYCxo> Crop yields in a geoengineered climate<http://www.youtube.com/watch?v=-0LCXNoIu-c> On Wed, Mar 21, 2012 at 7:30 PM, John Latham <[email protected] > wrote: > Hello All, > > I am probably missing a crucial point or two - if so please > correct me - but I am failing to understand the current almost > absolute focus on sulphur as a seeding agent. > > In the case of stratospheric seeding the case for sulphur seeding > is of course strong, but even then it seems worthwhile to have a > serious look at alternatives. The attached comprehensive and > authoritative paper by Rod Hyde, Lowell Wood & Edward Teller > provides such an examination with rigorous physical understanding. > At the least, we need to know what alternatives exist in case > some problem arises with the use of sulphur aerosol. > > In the case of tropospheric seeding with sulphur, as has already > been said, the public reaction is likely to be violently adverse.So > it seems vital to ask why this is the approach that so many people > seem to be advocating - or at least considering much more fully > than alternatives. Unfortunately I do not have the requisite > knowledge to name such, except to raise the possibility that > seawater aerosol seeding (which is of course central to the > in-cloud MCB idea) could also be used for out-of-cloud > tropospheric seeding. It is likely to be much more benign > than tropospheric sulphur seeding. > > All Best, John. > > > John Latham > Address: P.O. Box 3000,MMM,NCAR,Boulder,CO 80307-3000 > Email: [email protected] or [email protected] > Tel: (US-Work) 303-497-8182 or (US-Home) 303-444-2429 > or (US-Cell) 303-882-0724 or (UK) 01928-730-002 > http://www.mmm.ucar.edu/people/latham -- 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.
