I finally got around to listening to the 1 hour and 77-minute audio coverage of the AMS seminars. The sound comes and goes at various points, but if you crank up the volume, most of it is audible. The real problems are during the Q&A. There are two presentations, Alan Robock's and Dale Simbeck's with each one approx. 45 mins in length followed by a combined Q&A. The Q&A starts at 93:45.
Robock's talk essentially follows the slides already posted and discussed here. At 16 mins, he notes that the changes in the Asian and African monsoons might cause problems with the food supply. This is somewhat less definitive than saying it will cause problems. He runs through the list of possible problems (the 20 reasons list) mentioning enhanced ozone depletion, unknown effects of changes in diffuse radiation on plant biology and that acid rain is not a concern. He notes that the loss in direct solar radiation would be great enough to stop concentrators from boiling water, essentially shutting them down, citing Mike MacCracken as the source for this. I would have to see some numbers on this as I'm not sure the level of aerosol would ever get that high. Robock also notes the potential danger if there were concurrent volcanic eruptions at the same time stratospheric aerosols were in use. He failed to mention that such large eruptions occur less often than twice a century. He also noted that any delivery systems would likely have large local environmental effects, but didn't elaborate. As for delivery systems, he said artillery guns on the size needed don't exist and he knows of no airplane capable of reaching the stratosphere, citing the KC-135. Of course, since the Pentagon will never award the contract for the replacement aircraft, that one's off the table anyway. Ha Ha. He noted the potential of damage to the planes from flying into the acid clouds repeatedly, a subject we covered here last spring. As I reported at the time, most of the damage would be to the canopy, but long term damage would need to be monitored. He made the statement that billions of weather balloons filled with H2 and H2S would have to be used. Again, the number is millions over decades, not billions. The balloon and hose idea (Wood and Caldeira) he said was a concept only. Actually, the Royal Soc. paper goes into some detail about how it would be used. He also said that the microphysics of particle formation is an issue. He said that small scale field tests would be useless in determining global climatic effects as they would not be large enough to cause a measureable response. He cited the recent AK volcanic eruption release of 1.5Tg S which he said had no effect. However, according to reports I cited here recently, the eruption didn't reach the stratosphere, so it is of no value in determining a threshold sensitivity. He concluded by noting that money is needed to determine the effectiveness and viability of aerosol geoengineering. The Q & A. 1. Seth Borenstein, AP. Wanted to know reasons for increased interest in geoengineering. Robock cited sessions he organized at AGU with twice as many submitted papers this year and said that interest in climate change in general and the Crutzen and Wigley papers were responsible. He said while a lot of talk, no funding and no one developing any technology. 2. Sam Thernstrom, AEI. Disputed Robock's earlier claim in his presentation that AEI is promoting geo as an alternative to mitigation and said they are studying it, not promoting it. Robock responded that not many people advocate geo at all. Thernstrom then said that the debate is not about immediate deployment, but possible future use. Thus, the need for more knowledge so that better decisions can be made. Moderator interrupts. Robock then asks if business is so interested in geo, why doesn't it fund the research? Would EPRI (Electric Power Research Institute-Palo Alto organization that coordinates research studies for the utility industry) fund the scientific research if the government won't do it, he said? Thernstrom responded that AEI is a think tank, not another EPRI. 3. Jeremy Richardson, Pew Center on Climate Change. Wanted to know how quickly the temperature would change and how fast the climate would respond to the aerosols and would it be able stop a rapidly disintegrating Greenland Ice Sheet. Robock said the aerosol would form in about 30 days and the temperature response would be rapid, but that because ice sheet melting is due to a number of factors, decreased solar radiation alone may not be enough. 4. Avi Goshen (tape is almost inaudible, so I probably butchered this guy's name), AAAS Policy Fellow wanted to know if Robock had studied the impact on ancient civilizations of weak solar cycles in terms of their disruption and collapse due to droughts allegedly brought on by the reduced sunshine. Robock said geoengineering or climate change could cause droughts. 5. David Green, National Weather Service. Wanted to know what is needed in terms of observations and measurements and who should do it in order that geo could be studied. Robock said better a observational system for stratospheric aerosols would be helpful, citing the now defunct SAGE-II satellite that provided data on Pinatubo. Green also wanted to know if we are monitoring the oceans and atmosphere properly to consider geo. Robock said that long term systems with stable technologies were needed. 6. Billy Baird, George Washington Univ. Wanted to know about OIF. Robock noted that Planktos went broke after a Science Magazine article came out that was unfavorable and then started talking about Climos, but the sound is inaudible (1:55). He was opposed to it, saying the technology is unproven. Baird also wanted to know if there was a way to gradually reduce aerosol as CO2 emissions are reduced (the Wigley overshoot scenario). Robock instead said his main concern was abrupt cessation. Say what you will about Alan, but the man knows how to stay on message. 7. "Erica" wanted to know the cost of geo which Robock said was unknown, but cited the $10-100 billion figure from NAS-92 and how even that pales by comparison with recent bailouts. Simbeck then said that the cost of delivery payloads to the stratosphere would be less than for space. Robock mentioned other scattering options like black carbon which he said would deposit on the ice caps and cause them to melt and specialized engineered particles which he said were speculative. Erica then asked about dangers to the environment. Robock referred her to his papers and slides. 8. Mike MacCracken from the Climate Institute said he was concerned about the negative tone of Alan's presentation and said given the rapid pace of climate change that the geo research needs to be done. He also noted that Alan had blurred the distinction between aerosol geoengineering and other geoengineering proposals. He also stated that the modeling studies done to date are simplistic studies of the results and impacts of mass pulsed injections and don't necessarily reflect what more complex delivery scenarios over time and space might find. Robock agreed with MacCracken and said he is now conducting modeling studies of aerosol over the Arctic in Spring and Summer only, to see if that would avoid affecting the monsoons. 9. Arch Bauer, National Research Council asked if there were other ideas for scatterers besides ones based on SO2 being considered. Robock mentioned Teller and "a certain sci fi writer who doesn't understand the atmosphere." After that, the moderator said that he wanted to make it clear that the geoengineering seminars (I don't see how the Simbeck talk was about geo) were not intended to be definitive, but to start the discussion. End of audio. ----- Original Message ----- From: Alvia Gaskill To: [email protected] Sent: Friday, December 12, 2008 2:19 PM Subject: AMS SRM Podcast http://www.ametsoc.org/atmospolicy/EnvironmentalScienceSeminarSeries.html itpc://esss.ametsoc.net/podcast.xml There is now an audio version of Alan Robock's AMS/Congressional briefing. I haven't listened to it yet and will be out of the office most of the rest of the day, so I won't get to do so until Saturday. You, on the other hand... --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
