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HI John, I'd agree about the aerosols to a point. It's not entirely clear on a large scale how they may affect cloud formation and knock-on effects (from what I have seen at least, always happy to be corrected). It's not a permanent or irrerversible albedo change which reduces concerns. What we don't know is, borrowing from experience in radiation physics, dose response. At what levels are there significant positive or negative effects? Sometimes the only way to test, especially when dose-response is not linear (e.g. radiation hormesis), is to have experiments comparable in scale as to the application itself. That's the only way you can find out what damage might be done. That's a diffcult 'experiment' to sanction. GCM models at the moment cannot model many aspects of geo-engieering accurately enough to quanitfy risks or CBAs adequately (in my opinion). On 13 May 2011 14:20, John Nissen <[log in to unmask]> wrote: > Hi Brian, > > Proposed geoengineering methods with stratospheric aerosols and cloud > brightening are surprisingly benign, I found to my surprise several years > ago, since geoengineering has always been denounced as being so dangerous. > No significant side-effects have ever been established. > > We have to be clinical about our treatment of our planet. If the patient > is dying of cancer, we have to consider chemopherapy - but only as long as > it takes to put the patient on the road to recovery. Any doctor who waits > to find out whether the patient *is* dying, is liable to end up with a > dead patient. > > BTW, the dangers of suddenly withdrawing geoengineering have been much > overhyped. Where did you get the idea that it could lead to a venus > environment? We could only get that if the methane does its worst. > > Cheers, > > John > > --- > > > On 13/05/2011 10:40, Brian Orr wrote: > > Tom, > > Very much the sentiments I was thinking of expressing. > > But I think there is one further point that needs stressing. Seeking how > we might use > geoengineering to 'save the Arctic from meltdown' because this is an > 'imminent' and > catastrophic possibility, is a very long way short of climbing into > 'wholesale geoengineering' > - possibly as the means of continuing with unfettered 'business as usual'. > > 'Wholesale geoengineering' has to be avoided like the plague if only > because once hooked > on that solution we can only wait for the time when it will inevitably fail > and the world will be > turned into Venus 'overnight'. > > But using it to address the Arctic emergency could hold back what appears > to be the most > critical of the many tipping points we see coming towards us - and give the > world more time > to de-couple our lives from carbon as far as is required to return us to a > more stable climate. > > Going down this road (which would only be decided upon finally through > the most intense > international negotiations since Copenhagen and would result in a firm > 'yes' or 'no' - there > doesn't seem much room for equivocation here), should give the world the > message that > the climate change crisis is real, tangible and most be given mankind's > utmost priority. > > Of course there will be those who will say "See, we can rise to any > challenge." But we've > always known they are the enemies of creation. > > Brian > > On 12 May 2011, at 21:35, Barker, Tom wrote: > > Well Mark > > I don't really want to get into a scrap with you, because I know you are a > good man, but I resent the labels of hubris and conceit that you like > throwing around. I for one am not saying that we are truly past mitigation, > and if we are, then we should apply reverse gear, rather than wait for the > inevitable without at least attempting to do something positive about our > 'fate', which is what you seem to me to be saying. Who is 'assuming we will > have an answer'? Not me. I am prepared to simply try, that's all. > I admit to not understanding your viewpoint. In a choice between fighting > a lion and an alsatian, I'll take the alsatian. Are you really saying you > would rather kneel gently in front of the lion and prepare yourself for the > end? > > We have, inadvertently I admit, been geoengineering for at least 200 years > in the wrong direction, and I am prepared to do some geoengineering in the > right direction to get us out of the mess we're in. If it doesn't go the way > we plan, it might still be better than trashing the biosphere, and not as > profound a change as a climate flip. If in the end, we fail, people will > then be able to 'prepare ourselves psychologically and culturally for the > inevitable' as you put it, if they want to, but I rather think there will be > resource wars and violence enough to prevent any dignified peaceful end. > > As for a lack of scientific rigour, I wonder if you are mistaking lack of > evidence for lack of science. It's OK to admit we don't know, but that does > not mean we should just give up meekly. We know enough to know how to try, > so why not? > > Tom > > > ------------------------------ > *From:* Discussion list for the Crisis Forum [[log in to unmask]] > On Behalf Of Mark Levene [[log in to unmask]] > *Sent:* 12 May 2011 10:29 > *To:* [log in to unmask] > *Subject:* Re: Actic Council meeting on Thursday - Scientists for Global > Responsibility - Emerging technologies: are the risks being neglected? 21 > May 2011 > > thanks, Tom for going to the trouble. > > The issue of the flip is entirely clear. What I'm less sanguine about is > this 'educated guess' notion for dealing with it, and as you breezily put > it a 'few lesser risks'. All this side of things, seems to me to be utterly > indeterminate. Or, if I could use a musical term Aubrey Meyer has been fond > of using (and hence known to both of us) with regard to a lack of scientific > rigour in the political determining of the degree of necessary carbon cuts > for mitigation to be effective: > 'aleatory'. The term is worth looking up. 'Educated guesses' in terms of > what is at stake here I'm afraid neither read as convincing or > assuring.... > > What then you might ask is the alternative? and my only answer at this > moment can be : if we are truly past mitigation (which seems to be the case) > then we must prepare ourselves psychologically and culturally for the > inevitable....and come to accept that this is our fate, or more precisely - > given what we, primarily in the hegemonic Western sphere, have done to the > biosphere - our *Nemesis*. > > Or put yet again, I think it's time we stopped assuming that we will have > an answer, a solution, another technical fix to the mess we have caused. All > that is a conceit and hubris, though highly indicative of the mental state > of 21st century dysfunctionality. It's time instead to find our > reconciliation with the planet, and hence *ourselves*, even *in the face *of > our own species destruction. That to me, given all that is implied here, is > still worth working and struggling for, whatever the remaining > time-scale....... > > mark > > > > > on 11/5/11 2:20 pm, Barker, Tom at [log in to unmask] wrote: > > Hi Mark > > > > We canıt, but we can make an educated guess by looking at what are known in > ecology variously as alternative stable statesı, regime shiftsı, > catastrophic shiftsı and other names. See for example work by Scheffer, > Carpenter, Folke, Moss. > > > > An environmental driver exists (might be steadily increasing nutrient > concentrations (or CO2)), and the system maintains itself regardless. But > pressure is building up, and suddenly it flips into a completely different > state. If the environmental driver is taken back (at great expense and > difficulty) to where it was when the system was in a desirableı state, the > system doesnıt change back. Reinforcing stabilising mechanisms hold it in > the new state (just as they did in the previous state, which was why it > didnıt change smoothly and is thus called non-linearı). With some > ecosystems, e.g. shallow lakes, subtle signs can be seen that it might flip > soon (Brock & Carpenter paper is good), but we know about these because it > has been seen many times. We can see signs in the planetary ecosystem > (Arctic and Antarctic ice, Amazon, deserts etc) that we are probably nearing > a flip, but this has not been witnessed before, and a lot is unknown. What > is will be like afterwards is pretty unknown too, but sure as cheese is > cheese, we wonıt like it, and it is hardly likely to be conducive to the > sort of life we know. Unprecedented mass extinctions are predicted by some. > > Preventing the flip is the top priority, thatıs why some people are > prepared to take a few lesser risks to avoid it. > > > > I Hope that helps, T > > > *From:* Mark Levene [mailto:[log in to unmask] <[log in to unmask]>] > *Sent:* 11 May 2011 13:53 > *To:* Barker, Tom; [log in to unmask] > *Subject:* Re: Actic Council meeting on Thursday - Scientists for Global > Responsibility - Emerging technologies: are the risks being neglected? 21 > May 2011 > > > Tom, > > question; > > if we can't 'know' how close we are to the 'flip' how can we 'know' the > outcome of "some sort of *measured* geoengineering project" ? > > mark > > > > > > on 11/5/11 11:22 am, Barker, Tom at [log in to unmask] wrote: > > In that case, you might as well have my reply to her. Tom > > > > I agree with the precautionary principle of course, but we are already > artificially manipulating the climate, and not trying to direct it to benign > ends. We don t have time to ensure everything is safe as it can possibly be > before we embark on some sort of measured geoengineering project. For one > thing, that sort of knowledge can never be known, and for another, there is > hysteresis in the system, and we can t know either what the result of a > flip would be or how close we are to one. What we do know is that we would > not be able to return to comparative stasis once the flip has occurred. And > what we are pretty sure about is that we are hurtling towards that tipping > point now, blindly. That seems to me to be the greater risk. > > > > I came across this quote from Churchill the other day. You might wish to > consider it in the light of climate change. > > > > ½They go on in strange paradox, decided only to be undecided, resolved to > be irresolute, adamant for drift, solid for fluidity, all-powerful to be > impotentS > > Owing to past neglect, in the face of the plainest warnings, we have > entered upon a period of danger. The era of procrastination, of half > measures, of soothing and baffling expedience of delays, is coming to its > close. In its place we are entering a period of consequences S We cannot > avoid this period, we are in it nowS - Winston Churchill November 12, > 1936 > > > > Tom > > > *From:* Discussion list for the Crisis Forum [ > mailto:[log in to unmask] <[log in to unmask]>] *On > Behalf Of *Mark Levene > *Sent:* 11 May 2011 13:21 > *To:* [log in to unmask] > *Subject:* FW: Actic Council meeting on Thursday - Scientists for Global > Responsibility - Emerging technologies: are the risks being neglected? 21 > May 2011 > > > from Tessa Burrington > > but extremely relevant to us all. > > mark > > > From: [log in to unmask] > To: [log in to unmask] > Subject: RE: Actic Council meeting on Thursday > Date: Tue, 10 May 2011 22:58:16 +0100 > > > I am on the Crisis Forum mailing list. I thought you might be interested in > the following conference - if you think it migh > > > > >