Here's the reference I used for soot. http://www.californiaskywatch.com/documents/htmldocs/geoengineering.htm
I am pretty sure that soot from burning rainforests caused significant regional cooling in SE asia. If I'm wrong please can someone set me straight. 2008/12/23 Mike MacCracken <[email protected]>: > I cannot imagine how adding soot to the atmosphere would lead to cooling > instead of warming. > > On the use of sulfates, indeed there were problems as a result of > deposition. The worst problems occurred when the sulfate was not lofted and > so dispersed, as opposed to local, concentrated deposition. Sometimes this > occurred well down some particular trajectories (such as UK to Scandinavia). > The question is whether there might be a way, by selectively determining > locations and the particular weather, to build up sulfate concentrations > over dark oceans rather than over land and forests. Certainly there would > still be (and likely are now) some adverse consequences, but one would seek > to minimize those. Then the question is how these impacts would compare with > the effects of the warming that is being alleviated--and how this would > compare with the balance for other approaches and the costs and challenges > of implementing the various approaches. > > Mike MacCracken > > > On 12/23/08 4:31 AM, "Andrew Lockley" <[email protected]> wrote: > >> Thanks, I hope others with opinions about this and other categories >> will put their views forward. >> >> I'm concerned by the use of sulphur in this way. It caused terrible >> damage to the forests of Europe in the 70s and 80s. At this time it >> was apparently difficult to establish exactly which sources were >> causing the problem. How can we ensure that this does not happen >> again? >> >> Furthermore, I understand that tropospheric soot is also very >> significant, and that some have proposed using 'dirty burn' in ships >> and aircraft to promote cooling. Smoke from rainforest fires in SE >> Asia is apparently sufficient to promote regional cooling. Should >> this go on the IN list? >> >> A >> >> 2008/12/23 Mike MacCracken <[email protected]>: >>> Dear Andrew-- >>> >>> Although not done intentionally (well, in many cases we have chosen not to >>> use the technology that would maximally limit emissions), we are already, >>> quite fortunately, creating a significant cooling influence with >>> tropospheric sulfate aerosols. While there are negative side effects, >>> comparing those against the impacts this cooling presently alleviates >>> (resulting from about the 0.5 C cooling influence) has not been done, but >>> might not be clear-cut. >>> >>> In that there is no overwhelming negative influence of the tropospheric >>> sulfate aerosols, one could well imagine increasing their amount, at least >>> to generate additional sulfate aerosols in regions where ecological impacts >>> are likely to be minimal. So, increasing tropospheric sulfur dioxide >>> emissions from the elevated stacks of coal-fired power plants or by some >>> other means of lofting the sulfur dioxide to above the boundary layer (where >>> its lifetime is long enough to allow conversion to sulfate aerosol) would >>> seem to be an option to be included in the IN category. Indeed, there may be >>> adverse impacts in terms of deposition and human health, but it may well be >>> possible to manage the emissions to that they occur only for trajectories >>> that take the sulfates out over the oceans or to other locations where >>> deposition would not be problematic. >>> >>> In fact, given the apparently increasing SO2 emissions from the new >>> coal-fired power plants in China (as evidenced by the high sulfate levels >>> shown in the figure in the IPCC WG I report), this approach to limiting >>> warming may already be having some effect--indeed, maybe, as in the mid 20th >>> century, sulfates may be what seems to be somewhat slowing the warming over >>> the past decade. >>> >>> Mike MacCracken >>> >>> >>> On 12/22/08 8:37 PM, "Andrew Lockley" <[email protected]> wrote: >>> >>>> >>>> Can anyone else help me 'rank' the technologies? Just because people >>>> talk about a tech lots doesn't mean it's actually any good! I'm >>>> getting the impression that the following are basically in/out >>>> >>>> IN >>>> Sea water spraying >>>> Sulphur stratospheric seeding >>>> Ocean fertilisation with iron/urea >>>> White roofs (nice but not very effective) >>>> >>>> DON'T KNOW >>>> Limestone powder into the sea >>>> Fake plastic trees >>>> Biochar >>>> Removing HCl from oceans >>>> >>>> OUT >>>> Nuclear bombs >>>> Space mirrors >>>> Shiny balloons >>>> Sea albedo from litter/pykrete >>>> Low level soot and sulphur burning >>>> >>>> This is obviously just a list based on my bar stool expertise. If >>>> anyone with more knowledge could help that would be appreciated. Any >>>> references to an objective ranking system that I can put in the wiki >>>> would be appreciated. >>>> >>>> A >>>> >>>> >>>> >>> >>> >>> > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. 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