Alvia I share you concern about Lomberg and premature cost estimates. However I must disagree about 'not a single cloud'. There are lots of examples of cloud albedo being increased by the extra condensation nuclei from ship exhaust and the Discovery Channel experiment produced a cloud from seeing flares that was much brighter than no cloud as a result of about one minute's output from a spray vessel.
If we do not like the results of a treatment pattern that replicates el Nino then we move the flotilla to the other side of the Pacific to get a controlled amount of la Nina. My own view is that a steady state is usually better than an oscillation and I would like to position vessels to apply a bit of damping. You are also concerned about remote control. There is an ongoing student/amateur competition for the first robot sailing vessel to cross the Atlantic. The have a site at http://www.gpss.force9.co.uk/autop.htm Some of the contributions are more serious than others but they are learning lots and my guess is that they will do it quite soon. The slow 2D problem of remote guidance of ships is much easier than for the fast 3D one of the drone aircraft now being used to target individual people in Waziristan. I would have much more confidence in a computer than a sleepy or drunken ship's officer and removing people removes many problems about supplies of food and water. You also inquired about the Arctic. It seems that if you go too far north you might get the wrong kind of cloud with ice not liquid drops. However a Joule reflected is a Joule reflected no matter where it is reflected from. We hope that climate modelers will tell us which area of sea will be far enough south and on course to reach the Arctic. Alan Gadian has also pointed out that most of the heat that gets to the Arctic is moved by winds and currents which are driven by the temperature gradient. Just reducing the mass flow by reducing the temperature gradient will give the arctic less heat to radiate out to space. I hope that you had time to read all the comments in the Telegraph. You can download it from http://www.telegraph.co.uk/earth/environment/globalwarming/5987229/Cloud-ship-scheme-to-deflect-the-suns-rays-is-favourite-to-cut-global-warming.html Stephen Emeritus Professor of Engineering Design School of Engineering and Electronics University of Edinburgh Mayfield Road Edinburgh EH9 3JL Scotland tel +44 131 650 5704 fax +44 131 650 5702 Mobile 07795 203 195 [email protected] http://www.see.ed.ac.uk/~shs Alvia Gaskill wrote: > Very interesting, but anything associated with Bjorn Lomberg the > notorious climate change denier makes me a little uneasy. Note his > comment about using geoengineering instead of reducing emissions. Is > he going to ask the Nobel Laureates to vote on whether they agree with > this? > > How can you vote on which solutions are most cost effective if you > don't even know if they work? Ridiculous. Why not take a poll of > people on the street? Hold a "Town Hall," or just make a wild guess? > > I don't know where the $230 billion figure came from for stratospheric > aerosols, but no calculations I've seen or run come anywhere close to > that unless they are summing costs over decades. Also, it's important > to compare apples to apples when evaluating costs. Costs of building > and launching the Flettner Fleet are not the same as operating it. So > there would be ongoing costs, although most of the cost would be > upfront. And if the remote control turns out to not be possible, > which is likely since this has never been done before, manned vessels > would drive the costs up considerably. > > The issue of "switching off" technologies if there are unintended > adverse impacts must take into account all impacts. If the aerosols > caused droughts that were unacceptable, that would probably show up > early on and the program could be stopped immediately and the effects > gone within a year. The cloud whitening could be stopped much sooner, > but it is doubtful that would make much of a difference in terms of > impacts as its impact would still be felt over a couple of seasons. > Remember, both of them reduce SST and water has a much higher specific > heat than air! > > As to "sea trials" of the cloud whitening technology, it is still > worth noting that not a single cloud has ever been whitened by this > method and until this can be shown to be possible, it's getting a > whole lot a ahead of things to be crowning it "the geoengineering > technology of choice." As far as not having an impact on rainfall, > note that El Nino is a weather pattern in the Pacific that affects > large parts of the globe. So just whitening clouds away from land may > not prevent distant impacts. Whatever happened to using this in the > Arctic to slow sea ice and ice sheet melting? > > Who is the "rival American team" seeking funding? General Motors? I > understand they are very experienced with "bailouts," so this should > be right up their alley. > > -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
