On Fri, Mar 21, 2014 at 12:59 PM, Telmo Menezes <[email protected]>wrote:
> > > > On Fri, Mar 21, 2014 at 5:24 PM, Quentin Anciaux <[email protected]>wrote: > >> >> >> >> 2014-03-21 17:19 GMT+01:00 John Clark <[email protected]>: >> >> >>> >>> >>> On Wed, Mar 19, 2014 at 10:50 AM, Quentin Anciaux <[email protected]>wrote: >>> >>>> >>>> >>>>>> The thing I most want to know about RCP4.5 is what RCP stands for, >>>>>> Google seems to think it's "Rich Client Platform" but that doesn't sound >>>>>> quite right. It must be pretty obscure, Wikipedia has never heard of RCP >>>>>> either. >>>>>> >>>>> >>>> For your information, that means "Regional Climate Prediction" >>>> >>> >>> I'm pretty sure it's not "Russian Communist Party" but are you sure it's >>> not "Representative Concentration Pathways"? >>> >> >> I'm pretty sure you must be dumb as dumb if you really think this... As I >> see we are in a thread talking about climate... >> > > This thread seems to be mostly about politics. To be fair, John seems to > be in the minority here in wanting to discuss this from a scientific and > technological perspective. > Only if by "discuss this from a scientific and technological perspective" you mean cast vague aspersions at various scientific claims (use of climate models to predict future climates, analyze prehistoric glaciation thresholds, predict how climate would respond to specific GHG reduction scenarios like RCP4.5) and technical projections (like the specific plan to get 69% of electricity from solar by 2050), based on whatever verbal argument appeals to him and without any expert opinion of his own to cite in support of this skepticism. > > He raises a number of points that I have raised myself in previous > discussions. Instead of focusing on such issues, pop culture distractions > (Fox News etc.) and political tribalism seem to get all of the attention. > I haven't talked about such political issues at all, although John seems to have plenty of enthusiasm for politically-based caricature of what "environmentalists" believe, based on cherry-picking the worst plans he can find trawling various websites rather than attempting any fair-minded survey of how many groups and prominent climate activists would agree with those plans. > > - Given the number of climate models and the fact that the majority of > them failed to predict the climate of the last decade, how confident can we > be in further predictions? > Climate models predict that there should be plenty of statistical fluctuation on the level of individual decades, so this amount of uncertainty is already incorporated into the range of predictions made by an ensemble of such models. And current temperatures do still fall within the range predicted by models from earlier dates like 2000 and 1988. I addressed both the issue of how well models have done in their predictions and the issue of the 15-year warming "pause" (which climate scientists seem to think they understand the causes of fairly well) in this post: http://www.mail-archive.com/everything-list%40googlegroups.com/msg50488.html The page at http://grist.org/climate-energy/climate-models-are-unproven/(from the series of responses to common climate skeptic arguments at http://grist.org/series/skeptics/ ) also has a basic summary of some of the evidence supporting the reliability of climate models. More generally, I would repeat the general point that I think the only Bayesian prior when looking at scientific questions is "assign a high a priori likelihood that experts in the field are correct when they broadly agree on the answer to some question, only revise that in light of changes in expert opinion, obvious failed predictions that don't line up with their theories, or acquiring enough expertise in the subject yourself to have an informed opinion on the detailed evidence." So if the experts in climate science are in broad agreement about climate models being reliable in the sense that actual temperatures will very likely fall within the *range* that they predict over many different runs (a statistical prediction rather than an exact one obviously), given the right emissions scenario, my default is to trust their judgment. To ignore expert opinion and think that you, as a layman, are just as qualified to draw conclusions about the reliability of models in *any* area of natural science seems to me to be a basically anti-scientific, anti-intellectual attitude. > - With current technology, how much would we have to shrink the global > energy budget to transition to sustainable sources? What would the human > impact of that be? This is too serious an issue for wishful thinking. > Theres 7 billion of us and counting. We need hard numbers here, that take > into account the energy investment necessary to bootstrap the renewable > sources, their efficiency and so on. > The usual idea is not to significantly "shrink the global energy budget" (although some shrinkage may be possible without sacrificing living standards if we can find more energy-efficient ways of achieving the same goals, as with things like hybrid vehicles and fluorescent light bulbs), but just to replace energy from fossil fuels with energy from other sources like nuclear, solar, wind, geothermal etc. I posted links to a number of detailed plans to do this here: http://www.mail-archive.com/everything-list%40googlegroups.com/msg50850.html > > - What is the probability that a climate catastrophe awaits us vs. the > probability that an abrupt attempt to convert to sustainable sources would > create a human catastrophe itself? > Look over the plans above, what kind of "catastrophe" do you think they would lead to? They are all gradual, so if the other energy sources like solar were proving much more unreliable or expensive than anticipated, it's not as if we'd have already shuttered all the fossil fuel plants and would be left without energy. > > - Given that environmentalists are claiming that it might even be too late > to advert disaster, why aren't we seriously considering geoengineering > approaches, as the one proposed by Nathan Myhrvold, which can be easily and > cheaply tested and turned off at any moment? > I don't think there's any widespread agreement among scientists that this would halt all the problems associated with high CO2 levels or on what the side effects would be...the article at http://www.wired.com/science/planetearth/magazine/16-07/ff_geoengineering?currentPage=allsays: 'Indeed, ever since that first 2000 study, nearly all geoengineering simulations that Caldeira has run point to unwanted consequences. Caldeira's response is that it's hard to see how those consequences would be anywhere near as nasty as simply letting global warming go unchecked. But the more geoengineering becomes a matter of public debate and concern, the more the downsides of a remade world come under scrutiny. First, there's the fear that injecting sulfate into the stratosphere could destroy much-needed ozone, which also declined markedly after Pinatubo. Another possible side effect is acid rain. But sulfur dioxide pollution from coal-burning power plants, one of the prime causes of acid rain in the past, never reaches the stratosphere -- it remains in the atmosphere's lowest layer, the troposphere, and rains out quickly as a result. The stratospheric sulfate from geoengineering would stay up longer and be more stable, so we would need less of it to begin with, which somewhat weakens the acid rain argument. But the deepest concern is that at a fundamental level we would be messing with a complex and incompletely understood system, one that -- even in the most powerful computer models -- can be rendered only partially. There will undoubtedly be unexpected results -- the "unknown unknowns," as climate scientists call them. That's why critics like Robock and prominent atmospheric-sciences historian James Rodger Fleming want to avoid "playing God with the elements," to use Fleming's phrase. Finally, while geoengineering could presumably lower the planet's temperature, it cannot correct the other consequences of mounting carbon dioxide pollution. For instance, as the oceans absorb more CO2 they acidify, and decreasing ocean pH levels threaten coral reefs and other marine ecosystems. No amount of stratospheric sulfate can reverse that.' Also, if you commit to this plan then you're less likely to make any attempt to reduce CO2, which means that after a while you no longer really have the option to "turn it off" even if it's leading to all sorts of nasty side-effects, because if you did the consequences of a sharp temperature rise could be even worse. The one geoengineering proposal that I believe is thought unlikely to have unwanted side effects is the fairly straightforward one of removing CO2 directly from the atmosphere (carbon capture)--it may be possible to construct "artificial trees" which remove CO2 at a rate equivalent to about 1000 real trees, so if such devices became cheap enough to mass-produce they could have a major impact. Some articles on this: http://io9.com/5950271/could-artificial-trees-solve-the-global-warming-crisis http://thisbigcity.net/are-artificial-trees-the-answer-for-carbon-capture/ Though for some skepticism of this approach (mostly related to cost), see here: http://www.rtcc.org/2013/01/08/high-costs-and-poor-policy-delaying-carbon-capture-technology-iea/ Getting more into sci-fi territory, my hope is that within a few decades robotics may have advanced to the point where industrial robots can manufacture and assemble almost any mass-produced good without any significant human labor needed, given the necessary raw materials and energy--this would include additional industrial robots, so in this case you'd have self-replicating machines so you could start with a small number and soon have as large a number as you had land zoned to put them on. If this is achieved I expect it would drastically reduce the cost of almost all manufactured goods (probably down to not much more than the cost of the raw materials and energy they were made from), to the the point where rapid construction of vast number of solar panels or carbon capture devices could be far less costly than it would be today. But since there's no way of knowing how long it would take to reach such a point, I don't think this hope should be an excuse for taking no action today--the plans for converting to solar energy I linked to above would all involve costs of a several hundred billion per decade for the U.S., which is certainly substantial but doesn't have much chance of bankrupting the economy (the government spent about $718 billion on 'defense and international security assistance' in 2011 alone according to http://www.washingtonpost.com/blogs/wonkblog/wp/2013/01/07/everything-chuck-hagel-needs-to-know-about-the-defense-budget-in-charts/) > > Also this: > > http://theenergycollective.com/robertwilson190/328841/why-germanys-nuclear-phase-out-leading-more-coal-burning > > > I don't think it's a good idea to phase out nuclear energy, at least not except as part of a plan where each nuclear plant shut down is going to be immediately replaced by a sufficient number of solar plants/wind farms etc. to generate the same amount of energy. Towards the beginning of my post at https://groups.google.com/d/msg/everything-list/o4oSfoHocIo/GHojLwsRbVgJ I posted a bunch of links showing that there are now many environmentalists and climate scientists who have come out in favor of nuclear power as part of the solution to working against global warming. Jesse -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
