Hello Michael, Interesting scenario.
Yes, I'm aware of the efficient ice-nucleating properties of biological aerosol. I'm not sure, however, whether you have in mind the role of ice in increasing outgoing LW radiation or decreasing SW radiation. Either way it's important to decide which type of cloud you wish to modify - unless you propose creating clouds. Seeding clouds with ice nuclei can prolong or reduce their lifetimes, according to the amount of seeding. The fastest growth of ice in clouds occurs when both ice and supercooled water coexist (in the same regions, with much more of the latter than the former). Before you write a proposal it's vital to determine whether the processes involved are consistent with the (surprisingly tricky) cloud physics. Good Luck, 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 ________________________________________ From: Michael Hayes [[email protected]] Sent: Friday, March 23, 2012 9:21 PM To: [email protected] Cc: John Latham; [email protected]; [email protected] Subject: Re: [geo] Re: Why exclusive focus on Sulphur? Dr. Latham et al., After you submitted the HydeTellerWood paper last year, it did change many of my concepts. I have been working upon a possible concept criteria which could guide current and future efforts. So far, I have only a few design criterion's. 1) Places a high value on social/political acceptance. 2) Have a high degree of environmental interface reaction down to the 3rd order effects. 3) Be adjustable to seasonal/regional/special situational (political) conditions. 4) Have positive ancillary social/environmental benefits. As far as I know, we have no available work on nor consensus of concept design value(s). Unfortunately, we are still in a stage which concepts are championed by individuals under values they themselves promote. There is nothing inherently wrong with that, however the developement of theiretical design values would help on a number of different important levels. The concept of large scale Geophysical Management Science (GeMS) is only starting and there will be many concepts put forth. How do we 'judge' them? Here is an example: Pseudomonas syringae http://en.wikipedia.org/wiki/Pseudomonas_syringae "Ice nucleating properties P. syringae, more than any mineral or other organism, is responsible for the surface frost damage in plants<http://en.wikipedia.org/wiki/Frost#Effect_on_plants>,[8]<http://en.wikipedia.org/wiki/Pseudomonas_syringae#cite_note-7> exposed to the environment. P. syringae can cause water to freeze at temperatures as high as -1.8 °C (28.8 °F),[9]<http://en.wikipedia.org/wiki/Pseudomonas_syringae#cite_note-8> but strains causing ice nucleation<http://en.wikipedia.org/wiki/Nucleation> at lower temperatures (down to -8°C) are more common.[10]<http://en.wikipedia.org/wiki/Pseudomonas_syringae#cite_note-Chapter4-9> The freezing causes injuries in the epithelia and makes the nutrients in the underlying plant tissues available to the bacteria.[citation needed<http://en.wikipedia.org/wiki/Wikipedia:Citation_needed>] P. syringae have ina (ice nucleation-active) genes that make Ina proteins which translocate to the outer bacterial cell wall<http://en.wikipedia.org/wiki/Cell_wall> on the surface of the bacteria where the Ina proteins act as nuclei for ice formation.[10]<http://en.wikipedia.org/wiki/Pseudomonas_syringae#cite_note-Chapter4-9> Artificial strains of P. syringae known as ice-minus bacteria<http://en.wikipedia.org/wiki/Ice-minus_bacteria> have been created to reduce frost damage. P. syringae have been found in the center of hailstones, suggesting that the bacterium may play a role in Earth's hydrological cycle.[5]<http://en.wikipedia.org/wiki/Pseudomonas_syringae#cite_note-BBC25May2011-4>" If a proposal were put forth using this as a key technology, how can we accurately/objectively compare it to all others? Michael On Wed, Mar 21, 2012 at 2:17 PM, Ken Caldeira <[email protected]<mailto:[email protected]>> wrote: 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<tel:%2B1%20650%20704%207212> [email protected]<mailto:[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]<mailto:[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]<mailto:[email protected]> or [email protected]<mailto:[email protected]> Tel: (US-Work) 303-497-8182<tel:303-497-8182> or (US-Home) 303-444-2429<tel:303-444-2429> or (US-Cell) 303-882-0724<tel: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]<mailto:[email protected]>. To unsubscribe from this group, send email to [email protected]<mailto:geoengineering%[email protected]>. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. -- Michael Hayes 360-708-4976 http://www.voglerlake.com<http://www.voglerlake.com/> -- 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.
