Bravo!! last year a friend and i proposed the use of salt to the same purpose..even wrote a message on this to members of the geoengineering group.. i hope this concept is pursued.
On Sunday, March 25, 2018 at 8:00:05 AM UTC-4, renaud.derichter wrote: > > http://www.sciencemag.org/news/2018/03/dusting-salt-could-cool-planet > doi:10.1126/science.aat6555 > A dusting of salt could cool the planet By Paul Voosen > Mar. 21, 2018 , 12:10 PM > > *THE WOODLANDS, TEXAS—*A last-ditch remedy for a climate disaster might > be waiting in your kitchen. If efforts to control greenhouse gases fail, > finely powdered salt spread through the upper troposphere could hold off > the sun's rays and cool the planet, researchers reported here today at the > Lunar and Planetary Science Conference. The approach could be more benign > than other schemes for putting a temporary hold on climate change. > > For several decades, scientists have suggested ways to “geoengineer” the > climate > <http://www.sciencemag.org/news/2017/01/us-should-pursue-controversial-geoengineering-research-federal-scientists-say-first>. > > Several proposals call for injecting microscopic particles, called > aerosols, into the stratosphere, the quiet region of the atmosphere above > the troposphere about 18 kilometers up from the equator. There they reflect > sunlight back into space, mimicking the influence of large volcanic > eruptions that have temporarily cooled the planet in the past. > > Such proposals often involve sulfates, particles that form in the > stratosphere from sulfur dioxide ejected by volcanoes, or other molecules > with high reflectivity, such as diamond dust or alumina (aluminum oxide). > But all these approaches have drawbacks, says Robert Nelson, a senior > scientist at the Planetary Science Institute who is based in Pasadena, > California. Sulfur dioxide, for example, could eat away at the ozone layer > or cause acid rain. > > Alumina could be even worse, Nelson says. Although it is extremely > reflective, it could embed in the lungs if inhaled and cause chronic > disease similar to silicosis. “I was raised in Pittsburgh, > [Pennsylvania,] and I remember as a child seeing black lung victims > struggling to get down the street.” Still, given the limited amount of > alumina that could be required, it’s far from certain such a health risk > would be a genuine concern. > > So Nelson continued to look for other reflective compounds that might be > less hazardous to human health. In 2015, he was studying evaporated salts > on the surface of other solar system bodies such as the dwarf planet Ceres > <http://www.sciencemag.org/news/2015/12/dwarf-planet-ceres-may-harbor-clouds-water-ice>. > > He soon realized that simple table salt is more reflective than alumina, > while also harmless to humans. Just as important, Nelson believes that > salt, when ground into small enough particles of the right shape and > dispersed randomly, would not block outgoing infrared heat released by > Earth, adding to its cooling effect > <https://www.hou.usra.edu/meetings/lpsc2018/pdf/1834.pdf>. > > Nelson is not the first to consider salt, says Matthew Watson, a > volcanologist at the University of Bristol in the United Kingdom. Watson > led a geoengineering experiment, called the Stratospheric Particle > Injection for Climate Engineering project, that was canceled in 2012. His > group briefly considered salt for stratospheric injection, he says, but > problems popped up. > > First, there's a lot of chlorine in salt, and chlorine can contribute to > destroying ozone. That alone could be enough to kill salt as a candidate, > Watson says. Few would likely welcome injecting a particle that could > reopen the ozone hole. "[This] could be a big problem," agrees David Keith, > an energy and climate scientist focused on geoengineering at Harvard > University. Salt is also highly attracted to water, and water is scant > enough in the stratosphere that injecting even limited amounts of salt > could potentially alter, for example, the formation of the realm’s wispy > clouds, to unknown effects. > > Nelson hopes these concerns could be addressed by injecting salt in the > high troposphere, above the clouds but below the stratosphere. He > also plans to look more closely at salt's properties; if he can resolve > some of these questions, he'd like to see a test of the particles above a > region forecasted to experience life-threatening extreme temperatures. This > would test the science while potentially benefiting society in the short > term, he says. Such a research effort could only come after thorough > engagement with the public, Nelson adds. > > But like nearly all scientists interested in geoengineering, Nelson > stresses that the strategy is no substitute for action to curb carbon > emissions. No type of solar radiation management, for example, would > prevent rising carbon dioxide from acidifying the oceans. This research > should only be done so the world can potentially buy itself some time, > Nelson says. “This would be a palliative, not a [long-term] solution.” > > **Correction, 21 March, 1:50 p.m.: This story was updated to clarify that > Nelson seeks to inject in the upper troposphere, not the stratosphere, as > previously stated.* > Posted in: > > - Chemistry <http://www.sciencemag.org/category/chemistry> > - Climate <http://www.sciencemag.org/category/climate> > > doi:10.1126/science.aat6555 > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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EnhancingSolar - revised.docx
Description: MS-Word 2007 document
