Ecologists weigh inhttp://eco.confex.com/eco/2009/techprogram/P15440.HTM
What she knows and what she says may be two different things. When I blew the whistle on the misleading Science paper that based Arctic ozone depletion on a doubling of CO2 by 2017, I expected a clarification or at least a response. Neither one was forthcoming. Now I see in the abstract for the ESA meeting a paper that describes essentially the same outcome. Were more realistic assumptions made this time around and the ozone depletion was still a problem, but less so than before or is it just as bad? I agree with the recommendation for studies on whether heating of the stratosphere would decrease ozone depletion. But you know, since finding things wrong with geoengineering is so much more popular, profitable, politically correct (or fun for some people), I'm not surprised that work remains undone. "Geoengineering Reduces Ozone Depletion" wouldn't make a very good sounding news article, now would it? Thursday, August 6, 2009 - 2:00 PM SYMP 21-2: Impact of geoengineered aerosols on the troposphere and stratosphere Simone Tilmes1, Rolando R. Garcia1, Doug E. Kinnison1, Andrew Gettelman1, Philip J. Rasch2, Ross J. Salawitch3, and Rolf Mueller4. (1) National Center for Atmospheric Research, (2) Pacific Northwest National Laboratory, Richland, WA, USA, (3) University of Maryland, College Park, MD, USA, (4) Forschungszentrum Juelich, Juelich, Germany Background/Question/Methods: Geo-engineering schemes have been proposed to alleviate the consequences of global warming by continuous injection of sulfur into the stratosphere. Volcanic eruptions in the past have shown that strongly enhanced sulfate aerosols in the stratosphere result in a higher planetary albedo, leading to surface cooling. However, model simulations show significant local temperature changes embedded in the global cooling as a result of geoengineering. Also large local precipitation changes, may occur in case of geoengineering. In addition to the impact on the tropospheric climate, the significant increase of stratospheric sulfate aerosol densities caused by geoengineering approaches enhances heterogeneous reactions in the stratosphere that lead to ozone loss. The potential for exceedingly high Arctic ozone depletion in the context of geo-engineering is known. On the other hand, decreasing halogen compounds in the atmosphere, brought about by the Montreal Protocol, result in a recovery of the ozone layer and lessen the potential impact of aerosols. Results/Conclusions The sensitivity of in the stratosphere to a proposed geo-engineering scheme is presented for future halogen conditions. Based on results of the NCAR, Whole Atmosphere Community Climate Model (WACCM), the enhanced volcanic aerosol loading in the geo-engineering simulation result in a one-to two-fold increase of the chemical ozone depletion for the Northern Hemisphere due to chemical and dynamical changes. A significant increase of ozone depletion in the Arctic polar vortex up to the end of this century was estimated from observations, likely resulting in dangerous increase in UV radiation at the Earth's surface that harmful impacts the biosphere. Further, the recovery of the Antarctic ozone hole would be delayed by several decades in case of geoengineering using sulfate aerosols. ----- Original Message ----- From: David Keith To: [email protected] ; [email protected] ; Climate Intervention ; Rob Jackson Sent: Sunday, August 23, 2009 1:13 PM Subject: [geo] Re: Ecologists weigh in Greg, I was at the ESA meeting and argued strongly for the need to do geoeng research. People keep falling into the trap of thinking that mitigation can avoid all need for the ability to manage solar radiation. I think I got some traction by arguing that cutting emissions is necessary but not sufficient. Geoengineering provides the only plausible means to manage the global climate risks posed by the CO2 we have already emitted; no matter how fast we reduce emissions, prudence demands that we study methods that offer the hope of limiting the environmental risks posed by the accumulation of fossil carbon in the atmosphere. These quotes don't reflect the meeting, they likely prepared before it. Rob Jackson: is that correct? Simone Tilmes was there. She and others are well aware that geo after the chlorine loadings decline would much lower impact. The other issue on this topic is that, as suggested by Crutzen, if geo heats that lower strat (as many, but not all methods would) it might reduce ozone loss by reducing the formation of PSC's. To my knowledge, no one has followed up on this in a serious way. -David ------------------------------------------------------------------------------ From: [email protected] [mailto:[email protected]] On Behalf Of Greg Rau Sent: August 14, 2009 4:12 PM To: [email protected] Subject: [geo] Ecologists weigh in Apologies if this has already been discussed, but thought some quotes in here were pretty precious. Article written in a curious mixture of tenses. Anyone go to this? "The bigger the scale of the approach, the riskier it is for the environment," [=small scale solutions to a big scale problem are less risky?] "Any large-scale fertilization could cause risks to ocean ecosystems as great as those of global warming itself," [On the other hand ignoring 70% of the earth's surface and the largest CO2 controller on the planet doesn't make a lot of sense either in solving a global CO2 problem. Where's the proof that land based ideas are going to solve the problem?] "Playing with the Earth's climate is a dangerous game with unclear rules.....We need more direct ways to tackle global warming, including energy efficiency, reduced consumption, and investment in renewable energy sources." [And what happens if those aren't enough and/or don't happen fast enough - isn't that also "a dangerous game"? How does carefully considering other options like geoengineering increase global risk? If at the end of the day research proves that no geoengineering options are worth it, then fine, please don't use them. Until then, since nothing else seems to be working, how about soliciting and actively investigating other ideas like geo? ] -Greg http://www.firstscience.com/home/news/breaking-news-all-topics/symposium-to-discuss-geoengineering-to-fight-climate-change-at-the-esa-annual-meeting_68460.html Symposium to discuss geoengineering to fight climate change at the ESA Annual Meeting - 6 Aug 2009 By Ecological Society of America Symposium to discuss geoengineering to fight climate change at the ESA Annual Meeting Ecologists call techniques a risky strategy at large scales Geoengineering techniques aim to slow global warming through the use of human-made changes to the Earth's land, seas or atmosphere. But new research shows that the use of geoengineering to do environmental good may cause other environmental harm. In a symposium at the Ecological Society of America's Annual Meeting, ecologists discuss the viability of geoengineering, concluding that it is potentially dangerous at the global scale, where the risks outweigh the benefits. "The bigger the scale of the approach, the riskier it is for the environment," says session organizer Robert Jackson , director of Duke University's Center on Global Change. Global alterations of Earth's natural cycles have too many uncertainties to be viable with our current level of understanding, he says. One global-scale geoengineering method, termed atmospheric seeding, would cool the climate by releasing light-colored sulfur particles or other aerosols into the atmosphere to reflect the sun's rays back into space. This approach mimics what happens naturally when volcanoes erupt; in 1991, for instance, an eruption of Mount Pinatubo in the Philippines cooled the Earth by 0.9 degrees Fahrenheit. But Simone Tilmes of the National Center for Atmospheric Research argues that despite its potential to create overall cooling, atmospheric seeding could cause significant changes in localized temperature and precipitation. Her simulations also predict that sulfur seeding could destroy atmospheric ozone, leading to increased ultraviolet radiation reaching the Earth's surface. "An increase in ozone depletion over the Arctic could lead to dangerous levels of ultraviolet light hitting the Earth's surface," she says. "In this case, the recovery of the ozone hole over the Antarctic could be delayed by decades." Another large-scale geoengineering scheme is fertilizing the oceans with iron to increase carbon uptake from the atmosphere. Charles Miller of Oregon State University says that ocean fertilization could create a rise in iron-limited phytoplankton populations, which by dying and sinking would use enough oxygen to create extensive dead zones in the oceans. In addition, he says, the maximum possible rate of ocean iron fertilization could only offset a small fraction of the current rate of carbon burning by humans. Ocean fertilization also does not alleviate the increasing problem of ocean acidification, caused by carbon dioxide from the increasingly carbon-rich atmosphere dissolving into seawater. In fact, Miller says, ocean fertilization schemes will likely exacerbate this problem. "Any large-scale fertilization could cause risks to ocean ecosystems as great as those of global warming itself," he says. Despite its apparent hazards at the global scale, Jackson thinks that research should continue on safer ways to use geoengineering at a smaller scale. Geologic sequestration, sometimes known as CO2 capture and storage, takes CO2 out of the atmosphere and stores it in underground reservoirs. Jackson says that this solution has the potential to store more than a century's worth of electric power emissions at a relatively low cost. He notes, however, that some potential risks of geologic sequestration include carbon leakage and the potential for interactions with groundwater. But on the planetary scale, most ecologists are skeptical of climate engineering. "Playing with the Earth's climate is a dangerous game with unclear rules," says Jackson. "We need more direct ways to tackle global warming, including energy efficiency, reduced consumption, and investment in renewable energy sources." ### Clifford Duke, Director of Science Programs at the Ecological Society of America, is co-organizer of the symposium. Additional speakers include David Keith from the University of Calgary and Phillip Duffy from Climate Central, Inc. The researchers will present their results in: Symposium 21 - The Environmental Effects of Geoengineering Thursday, August 6, 2009, 1:30 PM-5:00 PM Pecos room, Albuquerque Convention Center For more information about this session and other ESA Annual Meeting activities, visit http://www.esa.org/albuquerque. The theme of the meeting is "Ecological Knowledge and a Global Sustainable Society." More than 3,500 scientists are expected to attend. The Ecological Society of America is the world's largest professional organization of ecologists, representing 10,000 scientists in the United States and around the globe. Since its founding in 1915, ESA has promoted the responsible application of ecological principles to the solution of environmental problems through ESA reports, journals, research, and expert testimony to Congress. ESA publishes four journals and convenes an annual scientific conference. Visit the ESA website at http://www.esa.org. Subscribe to ESA press releases by contacting Christine Buckley. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
