http://www.canberratimes.com.au/news/local/news/general/engineering-the-eart h-forums-big-ideas/2303296.aspx?storypage=0
Engineering the Earth: forum's big ideas BY BREANNA TUCKER 26 Sep, 2011 12:00 AM Shading the Earth under a giant umbrella, painting roofs white and simulating volcanic eruptions have been proposed as the latest solutions to climate change. The seemingly wacky set of ideas will be explored by more than 65 scientists today as Canberra hosts a forum on the controversial field of geoengineering. This comparatively new area of science recognises that human attempts to reduce carbon emissions will not be enough to combat climate change alone. Instead, scientists believe they may need to fiddle with the Earth's physical and chemical make-up to cool the planet and absorb more carbon dioxide. The only problem is that all the ideas scientists have come up with so far run the risk of creating dangerous side effects, ranging from overwhelming cancer rates to ocean acidification. University of Melbourne Earth sciences professor David Karoly said geoengineering had been debated across the US and Britain but this week's Geoengineering the Climate symposium was the first time the issue would be comprehensively debated in the southern hemisphere. ''The key thing to remember is that these strategies are designed to compliment, or work in parallel, to our attempts to reduce the burning of fossil fuels and creating greenhouse gases,'' he said. Topics for the week are split into two key strategies: to reverse global warming by cooling the planet or to enhance removal of carbon dioxide from the atmosphere. Under the cooling argument, scientists initially thought they could reflect sunlight by painting all the roofs of the world's buildings white or by creating an umbrella of space reflectors. Both ideas were dismissed as impractical given the large area that would have to be covered and the risk of reflectors colliding with stars and becoming space junk. Instead, researchers are now looking at simulating volcanic eruptions by injecting dust and other small particles into the air. ''It has long been known that particles from volcanic eruptions stay in the upper atmosphere for one to three years and can lead to a cooling of the climate system by up to three-tenths of a degree,'' Professor Karoly said. But this idea has also been rejected as such particles are likely to enhance depletion of the ozone layer, which will let more UV rays in and increase global rates of cancer. The particles would also eventually drop back down to Earth, worsening lung disease and polluting the ocean, which would in turn increase ocean acidification. Another school of researchers have suggested the thick, white clouds created by the smoke stacks of ships could increase cloud cover and reflect sunlight. ''The major adverse impact of this one is that the changes in sunlight would affect rainfall patterns and, again, it wouldn't have any long-term impact on slowing down carbon dioxide absorption, hence we would still have ocean acidification.'' On the issue of absorbing carbon dioxide, scientists are exploring simple concepts such as planting more trees, changing farming practices to improve carbon absorption in soil and storing carbon underground to fuel coal factories. A more complex idea of injecting iron into the ocean, to help marine algae and photoplankton absorb more carbon, have also been explored but were found to have only short-term effects. Mr Karoly said a number of scientists were excited by the idea of geoengineering but many were also concerned that ill-informed policies could make the world even worse-off than it is today. ''I find it concerning because it reminds me of the times when Australia brought in cane toads to solve the problem of the sugar cane beetle,'' he said. ''We are looking at technological solutions with adverse impacts that could leave us in a situation that could be worse than the problem we first set out to tackle. ''Before any specific initiatives take place we need to have more research and more open discussion about the potential benefits and problems, and that is what this forum is all about.'' +The Geoengineering the Climate symposium is a joint initiative of the Australian Academy of Science and the Academy of Technological Sciences and Engineering. It will run today and tomorrow at The Shine Dome, in Canberra. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
