> But so far I have yet to see any > discussion of what probablity of really catastrophic climate change it would > take to justify some kind of tangible sacrifice. So far the discussions > seem to encompass mostly arguments about whether or not it is worth "a > single american job" and the underlying assumption that 100% certainty of > anthropogenic causes is required before any change in policy is justified.
The discussion is often very tribal, and very black and white. Either it's not anthropogenic, then we do nothing, or it is anthropogenic and then it's obvious what needs to be done, and it's just that Bush is too stupid, or politicians are too corrupt ... 100% certainty that climate change is anthropogenic wouldn't be a sufficient reason to reduce emissions, we might still decide it's worthwhile. Americans might even think it's worthwhile precisely because it hurts certain developing nations, in spite of everyone getting hurt, as long as others get hurt more. See, that's the geogreen argument for reducing oil dependence, making poor Arab nations suffer is just and right, because they must be made to starve so that they cannot finance terrorism any longer, and as long as they suffer more than us, it's a moral duty for us to accept a little suffering as well. > I think the IPCC is too complacent a vehicle to fully frame the important > questions. I think Michael Tobis has made this point frequently, but it is > not only rational, but essential, to provide insight into the possibilities, > even if the uncertainties are huge, of really disasterous occurences. eg. > if the science can not *rule out* with greater than, say 99% (higher? > lower?) certainty the release of huge quantities of ocean sediment methane > then that should be on the table, front and center. The possibility of sudden methane release is part of the debate on climate change. I am not sure why you think that the IPCC is too complacent to address this or similar issues. > I recall thinking when James et al's paper on climate sensitivity came out > where they find 95% certainty of sensitivity less than 4.5oC that that is > simply not an acceptable risk. 5% chance of 4.5oC warming before 2100 is > *not* good news! And this does not even consider (as far as actual > temperature projections go) carbon feedbacks from permafrost and oceans. > Can science tell us that this *will not* happen with 99% certainty? A lot goes into the decision as to what's "acceptable risk". One is that there are other areas with potentially very serious risks. Lack of education may make India and Pakistan sufficiently unstable in 2020 to lead to a nuclear exchange killing hundreds of millions, say, lack of research into HIV may mean billions dead when the disease becomes as easily transmissible as the flu and immune to currently known treatment options. Currently, there's a debate about how close Iran is to having nuclear weapons. Bush does talk about it being unacceptable for Iran to have nuclear weapons. But, is it an "unacceptable risk" and if so, what should be done about it? Some people might say, regime change is a good option in any case, and considering that even a 5% risk is unacceptable, let's invade. Others might say that Iran having nuclear weapons (temperatures rising by 6C) wouldn't be worth the risk of invasion (strangulating the economy and killing millions in developing countries), even if it was 100% certain, never mind 5%. > I'm 0 for 2, here, let me clarify. I meant to say that you have several > times quoted the public's expectations of future risks as if that were a > gauge of the reality. It does not matter to the reality of the situation if > the public by and large is or is not worried. I didn't mean it that way. You've been talking about corruption, Alastair about psychology, and I've basically said that I am unconvinced by these explanations and that I think it (the current magnitude of sacrifice/action for the sake of climate change) is more a matter of the public being relatively unworried, ie they don't think climate change is really a threat on par with WWII Nazi Germany. > Yes, Alastair's take is well beyond the consensus. It is beyond my personal > assessment. But I can not say what he fears is *impossible*. And as soon > an outcome is (practically) not impossible it should be on the table, it > should be assessed as to how likely or unlikely it is and it should be in > the equation used when deciding what to do. Yes, I agree with all that, and I think it is part of the decision making. It is certainly part of mine. > Yes, peak oil can change everything. It could be in good (for CO2 > emissions) ways, or bad ways. I think this is kind of like trying to > predict the path of not one, but two hurricanes that are about to collide. > > > http://www.oilcrisis.com/laherrere/EGUVienna2006.pdf Emissions could still be high, as most of the carbon is stored in coal. My main point here was really that Laherrere is not within what the IPCC authors considered consensus while doing their scenarios. > I don't think the scenarios incorporate the effects of the climate change > they go along with, do they? ie I don't think you can look at the A1F1 > scenario and say "see, een the IPCC says economic growth will be good with a > 5oC temperature change by 2100". Is that what you are saying? I think they are presenting reasonable forecasts for the future, and those look quite optimistic, and are certainly a far cry from a view that the end of civilisation is certain. I also think that the IPCC considers the effect of climate change on emissions and economic growth small (of course my reading of the IPCC reports may be mistaken). They don't attach probabilities to their scenarios, they don't exclude the possibility of way out scenarios, but still, they argue their scenarios are a reasonable view of the future. The scenarios imply that high economic growth, if powered by coal, may mean 5C by 2100. ----------------------- Biodiversity You frequently mention the issue. My take is that biodiversity is virtually entirely an esthetic/moral value issue, ie I think agriculture/forests in so far as they are of economic value don't depend on whether Brazilian rainforests contain 1 million beetle species or 20. I also think that any species we really care about (say polar bears) we can keep in zoos or reservations, and if ecosystems change that isn't a big issue as such, they may still be esthetically attractive (and could be populated with polar bears, and be it human fed polar bears that are regularly checked up on by vets). I don't buy the Gaia hypothesis at all. I think if 99% of species died, and we had lawns and a few tree species and flowers, and the vegetables and animals we actually eat, it would make little difference to us. And I am very anthropocentric in my moral view of the universe. In the end, I don't accept that we have a moral duty to save species. I couldn't care less about some moss or lichen in Greenland not making the transition to a different climate. If it's a matter of saving animals/plants, or saving humans, I very strongly tend towards saving humans. The argument about biodiversity has some moral and some scientific part to it. If you could convince me that biodiversity actually mattered significantly economically, let alone for humanity's survival, you could rationally convince me of your case. However, in so far as it's a question of, can we save the polar bear's ecosystem and how much should I care about a possibility that climate change might make it harder to do so, you'll find that I heavily discount some worst cases there, because in the end, even if we couldn't keep polar bears in zoos and we'd consign them to the dust bin of history, I wouldn't care all that much (not to say not at all, there's a spectrum here as with many things) . --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. 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