Hello Jim, A couple of points re yr interesting letter. I'm in agreement with the spirit of your arguments and much - but not all - of the detail:-
1. I think that the SO2 scheme holds sufficient promise of being able to produce a valuable global cooling that it clearly merits further attention and provision of the necessary funding. If the additional atmospheric SO2 concentration is a small fraction of that produced in other ways, as it is generally stated to be, it could well be that the benefits of its deployment outweigh the disadvantages. 2. I'm glad you find merit in our cloud-albedo-enhancement scheme. Recent GCM computations (by Phil Rasch and Jack Chen) provide encouraging (though certainly not definitive) indications that globally averaged surface temperature stabilisation could be achieved up to the 2xCO2 point. The reason that such appreciable cooling is in principle possible, as of course that the areal coverage of marine clouds suitable for seeding is so large - about 15 - 20% of the Earth's area. However, both these schemes (and others) would founder if research identifies the existence of significant adverse ramifications associated with their possible adoption. It is too early to know whether or not this will be the case. All Best, John. John Latham Quoting jim woolridge <[email protected]>: > > Perhaps the primary objection to any and all of the geoengineering > proposals that have so far been put forward is the 'unforeseen and > unintended consequences' one. This is, of course, a powerful > objection, as Australian rabbits, Aral Sea fish and many other > instances testify. The unforeseen consequences argument itself goes > back at least as far as Plato (somewhere in the 'Republic', if memory > serves.) > > Our knowledge of earth systems and database of unintended > environmental consequences is by now rich enough to hold out some > chance of getting things right in the future--indeed exploring the > possible downside consequences of geoengineering ideas seems to be a > large part, quite rightly, of what happens on this site. Bearing the > foregoing in mind I have tried to come up with some ecological > criteria for geoengineering/earth systems adjustments--the > reversibility one has already been floated in an earlier post. > > The aim of the criteria is to keep adjustments to earth systems inside > existing biosphere processes so that the tweaking of those processes > does not violate the homeostasis of the biosphere. The criteria are > that: > > Whatever is done: > (1) Should not be a novel process but should either amplify or dampen > an already existing biosphere process. > (2) Should not itself be polluting. > (3) Should be reversible/stoppable. > > To briefly give examples re each criterion in turn: > Putting reflective mirrors between the earth and the sun is a novel > process, hence violates the first criterion; > Putting clouds of sulphur dioxide into the atmosphere is itself > polluting and hence violates the second criterion; > Putting iron filings into the ocean is not reversible (how can you get > the damn things out?) and hence violates the third criterion. > Obviously in the above examples each instance may well violate more > than one criterion. > > (For connoisseurs of synchronicity: just after writing the above I > came across Goethe’s Maxim 85: ‘Nature doesn’t worry about mistakes. > She repairs them herself and doesn’t ask herself what the upshot of it > all may be.’) > > There seem to be some options that hold out a prospect of non- > polluting, reversible and ‘natural’ ways of adjusting earth systems. > The most obvious ones are the Latham/Salter yachts; white roofs; > Kithil/Lovelock/Rapley ocean pipes. Indeed the yachts and pipes gave > me the idea for the criteria. > > The above will no doubt go down like the proverbial lead balloon with > many, if not all, subscribers to the group--sorry about that folks but > unintended consequences are likely to be less severe with the three > criteria in place. > > > > > -- John Latham [email protected] & [email protected] Tel. 303-444-2429 (H) & 303-497-8182 (W) --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
