Note: due to the way the search on their site is done, these abstracts won't appear in the order that they did on the program schedule I just published.
http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=geoengineering&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c617%7c2060%7cGeoengineering%20and%20the%20Problem%20of%20Harm%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c54479013%2054481073%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt 09:39h AN: U41E-10 TI: Geoengineering and the Problem of Harm AU: * Bunzl, M EM: [EMAIL PROTECTED] AF: Rutgers Inititative on Climate and Social Policy, Eagleton Institute of Politics,Rutgers University, 191 Ryders Lane, New Brunswick, NJ 08901, United States AB: Suppose geoengineering "works" and that there are no competing antagonistic interventions. Even on this rosy scenario, it is extremely unlikely that it will "work" for everyone since (as Schneider pointed out many years ago) there is no reason to think the effects of geoengineering will offset the effects of global warming locally. But as Robock et al have argued (Robock, Alan, Luke Oman, and Georgiy Stenchikov, 2008: Regional climate responses to geoengineering with tropical and arctic SO2 injections. J. Geophys. Res., in press), things may even worse than that. Suppose in some places (e.g. India), climate change + geoengineering leaves you worse off (hotter and drier) than climate change alone. Might it nonetheless be fair to proceed on the basis of the numbers – that is if many more would benefit than those who would not? I consider under what circumstances we may "let the numbers count", and where it is wrong to do so, irrespective of the numbers. I argue that the case of geoengineering is one in which we may let the numbers count, but only under conditions that are extremely difficult to satisfy. UR: http://www.csp.rutgers.edu DE: 6699 General or miscellaneous SC: Union [U] MN: 2008 Fall Meeting [Comments from me. Agreed that we could get into some kind of 7 million vs. 7 billion argument. Some must die so the rest may live. The point of using geoengineering as a preventative tool and not a fire extinguisher on a burning house is to limit the collateral damage. A point seemingly always ignored by the opponents as it doesn't fit their narrative. AG] http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=geoengineering&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c476%7c1809%7cGeoengineering%20by%20seeding%20boundary%20layer%20clouds%20using%20two%20climate%20modeling%20paradigms%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c54474300%2054476109%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt U41E-08 INVITED TI: Geoengineering by seeding boundary layer clouds using two climate modeling paradigms AU: * Rasch, P J EM: [EMAIL PROTECTED] AF: PNNL, P. O. Box 999 MSIN: K9-34, Richland, WA 99352, United States AU: Chen, C EM: [EMAIL PROTECTED] AF: NCAR, P. O. Box 3000, Boulder, CO 80307, United States AU: Latham, J EM: [EMAIL PROTECTED] AF: NCAR, P. O. Box 3000, Boulder, CO 80307, United States AB: We explore the Earth system climate response to geoengineering by seeding maritime boundary layer clouds. We contrast the response of the system using an atmospheric GCM coupled to two different formulations for sea ice and ocean dynamics: 1) a full ocean and dynamic sea ice model; 2) a slab ocean model with a thermodynamic sea ice model. We show that the climate response is quite different in the two formulations and explore the reason for the difference. DE: 0320 Cloud physics and chemistry DE: 0429 Climate dynamics (1620) DE: 1600 GLOBAL CHANGE SC: Union [U] MN: 2008 Fall Meeting http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=geoengineering&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c436%7c4793%7cUse%20of%20Volcanic%20Eruptions%20as%20a%20Natural%20Analog%20for%20Evaluating%20Effects%20of%20Stratospheric%20Geoengineering%20on%20the%20Hydrological%20Cycle%2c%20Ocean%20Heat%20Content%2c%20and%20Sea%20Level%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c54466652%2054471445%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt U41E-06 TI: Use of Volcanic Eruptions as a Natural Analog for Evaluating Effects of Stratospheric Geoengineering on the Hydrological Cycle, Ocean Heat Content, and Sea Level AU: * Stenchikov, G L EM: [EMAIL PROTECTED] AF: Department of Environmental Sciences, Rutgers University, 14 College Farm Rd., New Brunswick, NJ 08901, United States AU: Ramaswamy, V EM: [EMAIL PROTECTED] AF: NOAA Geophysical Fluid Dynamics Laboratory, Princeton University, P.O. Box 308, Forrestal Campus, Route 1, Princeton, NJ 08452, United States AU: Delworth, T L EM: [EMAIL PROTECTED] AF: NOAA Geophysical Fluid Dynamics Laboratory, Princeton University, P.O. Box 308, Forrestal Campus, Route 1, Princeton, NJ 08452, United States AU: Stouffer, R J EM: [EMAIL PROTECTED] AF: NOAA Geophysical Fluid Dynamics Laboratory, Princeton University, P.O. Box 308, Forrestal Campus, Route 1, Princeton, NJ 08452, United States AB: Large-scale human intervention into natural systems, geoengineering, is considered as a means to counterforce global warming. Among the discussed geoengineering schemes one of the most feasible (because of its relatively low cost and existing natural analog) is based on injection of sulfur aerosols or their precursors into the stratosphere (therefore here we call it "stratospheric geoengineering") to increase the Earth's planetary albedo and cool the Earth. Recent model studies, however, indicated reduction of precipitation as a side effect of injection of scattering aerosols in the lower stratosphere, and did not assess the forced long-term effect on ocean circulation and thermal structure. In this study we take advantage of the analogy between stratospheric geoengineering and volcanic impacts to better quantify the effects of geoengineering on hydrological cycle and the ocean that are crucial for assessing biospheric and economic consequences of geoengineering. We employ the coupled climate model CM2.1, developed at NOAA's Geophysical Fluid Dynamics Laboratory, and simulate responses to quasi-permanent geoengineering forcing, as well as transient impacts of the 1991 Pinatubo and 1815 Tambora eruptions. Testing volcanic model simulations against observations allows us to more reliably estimate the range of climate system responses to stratospheric aerosols, their dependence on the magnitude of forcing, and associated characteristic times. We found that stratospheric aerosol cooling intensifies ocean vertical mixing and tends to strengthen the meridional overturning circulation. Sea ice appears to be sensitive to volcanic forcing, especially during the warm season. Volcanic ocean temperature signals scale roughly linearly with respect to radiative forcing, but ocean overturning circulation response is less than linear. In two-three years after injection of aerosols, while ocean temperatures decrease and the global hydrological cycle remains suppressed, precipitation over land tends to recover. The quasi-permanent cooling from geoengineering aerosols penetrate into the deep ocean more slowly than from sporadic volcanic cooling, which more vigorously intensifies ocean vertical mixing. Ocean subsurface temperature, sea level, and overturning circulation have an extremely long relaxation time of about a century. Therefore geoengineering consequences in the ocean, despite a quicker atmospheric temperature recovery, will be felt for at least a century after geoengineering forcing is turned off. DE: 0305 Aerosols and particles (0345, 4801, 4906) DE: 0370 Volcanic effects (8409) DE: 1854 Precipitation (3354) DE: 3319 General circulation (1223) DE: 4215 Climate and interannual variability (1616, 1635, 3305, 3309, 4513) SC: Union [U] MN: 2008 Fall Meeting [Comment. Not quite sure what the point of this one is. Is this based on a gradual ramp up of aerosol such that the sudden (6 months) cooling from a volcanic eruption is not experienced? The conclusion implied, but not stated, is that after the geoengineering ceases, the effects on global precipitation will continue for many years as the surface ocean remains cooler than before. AG] http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=fm08&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=geoengineering&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c429%7c3940%7cGeoengineering%20and%20the%20Risk%20of%20Rapid%20Climate%20Change%7cHTML%7clocalhost:0%7c%2fdata%2fepubs%2fwais%2findexes%2ffm08%2ffm08%7c54566369%2054570309%20%2fdata2%2fepubs%2fwais%2fdata%2ffm08%2ffm08.txt 1340h AN: U43A-0038 TI: Geoengineering and the Risk of Rapid Climate Change AU: * Ross, A J EM: [EMAIL PROTECTED] AF: Concordia University, 1455 De Maisonneuve Blvd. West, Montreal, Qc H3G 1M8, Canada AU: Matthews, D EM: [EMAIL PROTECTED] AF: Concordia University, 1455 De Maisonneuve Blvd. West, Montreal, Qc H3G 1M8, Canada AB: Many scientists have proposed that geoengineering could be used to artificially cool the planet as a means of reducing CO2-induced climate warming. However, several recent studies have shown some of the potential risks of geoengineering, including negative impacts on stratospheric ozone, the hydrologic cycle and the possibility of rapid climate change in the case of abrupt failure, or rapid decommissioning of geoengineering technology. In this study, we have emulated a geoengineering scenario in the MAGICC climate model, by counteracting the radiative forcing from greenhouse gases. We have used a hypothetical scenario of business-as-usual greenhouse gas emissions, in which geoengineering is implemented at the year 2020, and is removed abruptly after 40 years. By varying the climate sensitivity of the MAGICC model, and using previously published estimates of climate sensitivity likelihoods, we are able to derive a probabilistic prediction of the rate of temperature change following the removal of geoengineering. In a simulation without geoengineering (considering only the A1B AIM emissions scenario) the maximum annual rate of temperature change (in the highest climate sensitivity simulation) was 0.5° C per decade. In the geoengineering simulations the maximum annual rate of temperature change, occurring in the year after geoengineering was stopped, varied from 0.22° C per decade for a climate sensitivity of 0.5° C to nearly 8° C per decade for a climate sensitivity of 10° C. The most likely maximum rate of change (corresponding to a climate sensitivity of 2.5° C) was just over 5° C per decade. There is a 99.8 percent probability that the rate of temperature change following the stoppage of geoengineering in this scenario would exceed 3° C per decade. This risk of rapid climate change associated with the use of planetary-scale geoengineering is highly relevant to discussion of climate policies aimed at avoiding "dangerous anthropogenic interference" in the climate system. Many ecosystems would be significantly stressed by the high rates of temperature change shown in this study, which could compromise ecosystems' ability to adapt to climate change There are also possible implications of rapid temperature change for other aspects of the climate system, such as the strength of the meridional overturning circulation. Based on the results of this study, we argue that the risk of rapid climate change following the abrupt removal of geoengineering could constitute increased risk of dangerous anthropogenic interference in the climate system. DE: 1225 Global change from geodesy (1222, 1622, 1630, 1641, 1645, 4556) DE: 1605 Abrupt/rapid climate change (4901, 8408) DE: 1635 Oceans (1616, 3305, 4215, 4513) DE: 3337 Global climate models (1626, 4928) SC: Union [U] MN: 2008 Fall Meeting [Comment. I still don't agree with the likelihood of abruptly stopping the geoengineering. As far as "adapting to climate change" many of these ecosystem species will be long gone if we don't do something soon. It is unclear from the abstract at what level the forcing is reduced, i.e., is the modeling based on offsetting new AGW forcing starting in 2020 and until 2060 or all of it accumulated to date? NOTE: So this won't become the longest e-mail in history, I will limit the number per posting so you can more easily read them. AG] --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
