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Comments 58301 to 58350:

58301. Composer99 at 00:03 AM on 6 June 2012
       Pal Review - the True Story and the Fairy Tale
       I'm sure that those accusing mainstream climate scientists of undertaking pal-review could surely come up with a similar network of connections to substantiate their accusations - if the accusations had merit, that is.
58302. Tom Curtis at 21:05 PM on 5 June 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       Leto @38: "An expert is someone who knows some of the worst mistakes that can be made in his subject and how to avoid them. WERNER HEISENBERG, Physics and Beyond" Heisenberg provides us with the best, succinct definition of expertise. In any field, somebody is expert if they don't make the bad mistakes. An expert batter (in baseball) will still make mistakes. But he will pop up a fly ball because he is trying to hit a home run against good pitching, not because it is pure chance for him to get a better hit. In science, the definition is particularly applicable. If you don't make mistakes in science, it just means you are not trying interesting hypotheses. But the mistakes of the expert are different from those of the non-expert. For a start, they are new mistakes. The expert knows his field well enough to know the mistakes others have made, and how to avoid them. Further, they are interesting mistakes. That is, they are mistakes which you need to learn something knew in order to discover that they where a mistake. Contrast that with Carter's performance above. Do we really learn something knew to discover that 29/360 is not 0.1 (10%) as Carter asserts (Cherry Sun)? Or that contrary to Carter, the radiosonde data shows a greater warming than the surface warming and does not follow a step function (Radios own goal)? Well, perhaps it is new to us, but to a climate expert? Or consider his only genuine scientific article in climate science. In it he took some temperature data, removed the trend, found a significant correlation with ENSO, and then concluded that ENSO explained the trend! Is it really a great discovery to find out that is a mistake? So, Carter claiming to be a climate expert is like somebody who falls prey to the Fool's mate claiming to be a Grand Master. The claim of expertise, given the types of mistakes he makes, is simply not credible. He is a fake expert.
58303. Harald Korneliussen at 20:58 PM on 5 June 2012
       New research from last week 22/2012
       Those pictures of Greenland are pretty, and would be good for encouraging interest in climate science. Pity the full resolution versions of them are paywalled.
58304. skywatcher at 18:41 PM on 5 June 2012
       Models are unreliable
       Hi JasonB, you provide a very interesting perspective there, and I think you make the most important point as well:

       It certainly wouldn't have less trustworthy just because it wasn't written by somebody with a CS degree.

       This is the key issue - is the code any less trustworthy because somebody wrote it who wasn't at the core, a CS specialist< and I concur with your answer that it is not. I don't doubt that (for example) code I wrote was a lot more 'clunky', poorly commented, inefficient and all the rest than a CS specialist's code! (though clunky 3D graphics were quite fun to do). Equally I suspect the coders of big GCMs are much more skilled at efficient algorithm generation than I ever was, as they need to be, running large computationally expensive programs. The core algorithms that controlled the scientific part of my programs were as you describe them - transcriptions of mathematical expressions, and computationally relatively straightforward to implement. Some algorithms are harder than others, of course! Ensuring they are correctly implemented is where detailed testing and validation comes in, to make sure the mathematics and physics is as good as you can make it. These are then documented and described in relevant publications, as with all good science. All part of the scientific coder's life. Thanks for your perspective.
58305. Leto at 18:12 PM on 5 June 2012
       Bob Carter's Financial Post Gish Gallop of Scientific Denial
       As a very occasional reader of climate science sites, including this one, I would like to add that I also find the tag 'fake expert' unhelpful in this case. I accept that Carter is less qualified than many others to comment on paleoclimatology. I also accept that his actual claims seem flawed, from which an inference can be drawn that his expertise is, indeed, minimal. I just don't see that tagging him as a 'fake expert' helps the argument. It would be different if he had never studied or published in a relevant field, and was unambiguously lying about his background, but that is not the case. If he wrote a sensible defence of AGW, with exactly the same credentials, would you think it necessary to call him a 'fake expert'? If not, then you are basically saying he is fake because he is wrong. If I have to accept the flaws in his position before deciding he is indeed a 'fake expert', then it is those flaws, rather than the tag, that do all the heavy lifting in the debate. Describing him as a 'fake expert' merely distracts from the otherwise interesting discussion of why he is wrong, and comes across to me (and possibly other readers) as an ad hominum argument. Readers who can already see why he is wrong will not be more convinced because you add the 'fake expert' tag. Worse, readers who are unconvinced of his errors will merely conclude that his errors are not sufficient in themselves, to carry the argument, and require propping up with attacks on his expertise. Cheers, Leto.
58306. JasonB at 17:36 PM on 5 June 2012
       Models are unreliable
       Perhaps some personal experience may be illuminating. Lest this be perceived as "dogpiling", I'm happy to respond in the context of skywatcher's claim "It is much easier to begin with an understanding of climate and physics, and graduate onto writing computer code, which is fundamentally not that difficult to do, than the alternative." I am part of a team of three people that writes scientific software (not climate-related). It involves modelling, calibration, error estimation, and 3D graphics, and the consequences of mistakes can be extremely serious. Two of us -- myself included -- are computer science graduates. The third has a PhD in the field that the software is actually used in. My CS degree was very heavy in mathematics (an option I took because I love maths) and the software is very maths-intense, which is obviously an advantage. I understand how the software works, and can explain it to others. However, the scientific innovations in the software usually come from the guy with the PhD in the field. I normally take his working implementation and optimise the hell out of it, as well as do all the 3D graphics stuff, etc., but he usually comes up with the core algorithms. He had no formal computer science training, and learnt most of his coding "on the job". His implementation is still often far from perfect, especially performance-wise, and he isn't aware of a pretty large body-of-knowledge about how to implement things well, but it still works. If he didn't have us, I believe he could still have produced working software that would have done the job, although it would have been orders of magnitude slower, less "fancy" from a user's point of view, and probably much harder to maintain and difficult to understand. It certainly wouldn't have less trustworthy just because it wasn't written by somebody with a CS degree. OTOH, if we didn't have him, we could still have written some software (I know, because we had more primitive software 15 years ago when he joined) but it wouldn't have been as sophisticated and it certainly would have taken us a lot longer to think up the algorithms that he has developed over the years. Writing computer code can either be extremely easy or the most difficult thing a human being can attempt to do. It depends on the nature and complexity of the code. Scientific code is generally not that complex from a computer-science point of view -- the important parts are simply direct transcriptions of mathematical expressions -- and so speaking as a computer scientist, it doesn't bother me in the least if no computer scientists are involved in the writing of GCMs. What they are possibly missing out on is optimised, multi-threaded implementations with wizz-bang 3D GUIs and easy-to-maintain code, but that doesn't change the correctness or reliability of the models. I also have no problem categorising people with a few decades of experience of writing code without CS degrees as "computer modellers". My PhD supervisor, like virtually all CS academics of his generation, had degrees in other disciplines (physics, in his case). It would be pretty absurd to classify me as a computer modeller but not the people who taught me!
58307. Tom Curtis at 17:21 PM on 5 June 2012
       Modelling the Apocalypse
       ranyl @19: 1) The list of scientific papers you appear to have copy and pasted from some bibliography includes many papers only tangentially related to this topic. The first two, for example, represent estimates of climate sensitivity rather than discussion of the carbon cycle. (I also note in passing that the list violates the intent of the comments policy stipulation that naked links not be provided. If you are going to cite papers, you should at least summarize them unless they are directly related to your comments, and it is clear from context how they are so related.) 2) Although you make a long list of factors not taken into account by the various models, in fact most of them do take most of those factors into account. Those which are not included (eg, nitrogen fertilization) are recently raised considerations, and it is not at all clear that they are well founded. 3) Suggesting that loss of the Arctic sea ice will have a similar albedo impact to the loss of the Laurentide Ice Sheet is just rubbish. Regardless of area and underlying surface, there is a vast difference in latitude and hence of effective insolation. Albedo effects from the loss of Arctic sea ice will be significant, but is not the game changer you imagine. Estimates of Equilibrium Climate Sensitivity based on the LGM, such as those by Hansen and Sato, already include the albedo effect of a larger loss of sea ice (a fast feedback) from lower latitudes. Therefore if that feedback is stronger than is thought, it must be because some other feedback is weaker than currently thought, for empirical estimates of climate sensitivity include all fast feedbacks by their nature. 4) The rate at which CO2 is carried to the deep ocean does not depend on CO2 "gradients". The pCO2 of atmosphere and surface ocean equilibriate in approx a year, with the ongoing removal of CO2 to the deep ocean being effected by the thermohaline circulation rather than by diffusion. As such, the rate of that removal is a function of pCO2 in the surface ocean and the pace of the thermo-haline circulation. Ergo, a pulse gives a reasonable estimate of the time to oceanic equilibrium. 5) I note, also, that even Lowe et al 2009 (your fourth reference)shows near flat temperatures in the first century after the complete cessation of emissions in all three scenarios she examines, even though she argues and models a very slow decline in CO2 levels: She even shows a limited probability of exceeding 2 degrees C provided emissions are kept below the trillion tonne limit (equivalent to the cessation of all emissions in 2050): It appears that my conclusion is fairly robust. Finally, if your respond again with a gish gallop as in your last post, I will not bother responding again.
58308. Riccardo at 17:21 PM on 5 June 2012
       Lessons from Past Predictions: Hansen 1981
       curiousd you can not use Beer's law to calculate the forcing; you can not even use it to calculate the infrared flux to space. You need to take into account the absorbed as well as the emitted fluxes, the vertical profiles and the wavelength dependence. This is what a radiative transfer code does. The simplified formula is just a empirical fit. Here's the paper.
58309. scaddenp at 14:47 PM on 5 June 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       Peter, (saw your post on RSS). Can I suggest you put comments on models in Models are unreliable and the LIA comments in We coming out of the LIA
58310. JasonB at 14:41 PM on 5 June 2012
       Lessons from Past Predictions: Hansen 1981
       curiousd, the logarithmic expression for dF in terms of CO2 concentrations is empirically derived from observations and calculations using radiative transfer codes, not established from first principles, and in fact it's only a first-order approximation that is "accurate enough" (given other uncertainties) for the ranges of CO2 concentrations that are of concern to us. As you can see from the TAR, various approximations have been used at different times by different authors, although they're all pretty similar. Because it's logarithmic, an exponential increase in concentration will result in a linear increase in temperature (ignoring feedbacks). Unfortunately, CO2 concentration has been increasing at a rate greater than exponentially so the CO2 forcing is growing faster than linearly.
58311. curiousd at 14:04 PM on 5 June 2012
       Lessons from Past Predictions: Hansen 1981
       Thanks CB.....short of it was that late at night I was misreading a stack of data on CO2. Sorry. One more tho.. Since it turns out that the dF = ln (C2/C1)x const leads to that exponential formula I got, this got me to thinking about where that logarithmic dependence on concentration comes from, since by standard Beer's law physics you would expect an exponential to a power with an effective absorption coefficient involved. I was digging all around the net and I guess maybe this ln dependence is empirical, and has to due with the fact that the CO2 only allows radiation to go through at the wings of the transmission window? If the derivation is really that hairy then for my purposes I don't need to go through it, but just checking here.
58312. Peter42 at 12:22 PM on 5 June 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       To Tristan @ 41 (01:34 AM on 4 June, 2012), JasonB @ #42 (11:42 AM on 4 June, 2012), scaddenp @43 (14:16 PM on 4 June, 2012), and adelady @44( 14:56 PM on 4 June, 2012): (-Snip-)
       Moderator Response:

       [DB] You have previously received moderation for being off-topic. The scope of this current comment far exceeds that of the OP of this thread. You are welcome to resubmit the applicable portions on applicable threads, separately. Note also that when engaging multiple participants at SkS it is considered good form to post separate comments to them. This prevents "dog piling".

       Please take the time to review the Comments Policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.

       Note that future comments constructed as this one will be summarily deleted.

58313. JasonB at 10:56 AM on 5 June 2012
       Ian Plimer Pens Aussie Geologist Gish Gallop #2 of the Week
       Tom @7, reading their other press releases also shows them boasting about the use of geothermal energy to "significantly reduce our carbon emissions". I guess not enough. This article quotes the SCA Hygiene president saying that it will "impact profits", but it also mentions two other companies will receive 94.5% of their needed carbon permits for free. (That article also puts to bed the idea that the carbon tax won't have any effect on emissions -- it's full of steps that the companies will take to reduce their carbon footprint.) Like you, I couldn't find any mention from SCA Hygiene about the carbon tax causing layoffs -- not surprising, given it hasn't even started yet. They do state how they've been hurt by cheap Asian imports, and a high A$ will no doubt cause them pain. The only connection I could find between SCA Hygiene, layoffs, and the carbon tax was posts by another fellow called "Dale" who claimed "SCA Global announced due to rising costs in wages, electricity and the carbon taxes in AU and NZ made the Australasian business unfeasible" without any references -- but again failing to note that the carbon tax hasn't even started yet, and electricity prices have risen in the past few years by far more than the carbon tax will cause it to rise in many parts of Australia without the carbon tax in place. What about the rising wage costs? Perhaps Dale was laid off because he cost more than workers in Indonesia? If the announcement was accurately reported, then it seems taking on "and the carbon tax" to every announcement of layoffs or closures will become a cliche. But even if it's the straw that breaks the camel's back of a business that's been put through the ringer due to rising wage costs, rising electricity costs (apart from the carbon tax), and a high A$, it's disingenuous to blame that final straw for the outcome -- after all, a slight additional increase in the A$, or salaries, or coal price, or... could have just as easily been that final straw, and as we've seen in announcements before the carbon tax is even in place, companies seem happy to use it as an excuse regardless of whether it actually has an impact or not.
58314. ranyl at 09:16 AM on 5 June 2012
       Modelling the Apocalypse
       16. Schneider B. “Global warmth with little extra CO2”, Nature Geoscience, VOL 3, pg. 6-7, 2010 17. Csank, A.Z., et al., “Estimates of Arctic land surface temperatures during the early Pliocene from two novel proxies”, Earth Planet. Sci. Lett. (2011) 18. Hansen, J. et al., “Climate simulations for 1880-2003 with GISS modelE.” Clim. Dynam., 29, 661-696, 2007 19. Lowe A. et al “How difficult is it to recover from dangerous levels of global warming?” Environ. Res. Lett. 4, (2009) 20. Solomon S. et al, Persistence of climate changes due to a range of greenhouse gases PNAS. October 26, 2010 21. Wang Y-P, et al, “Nitrogen constraints on terrestrial carbon uptake: Implications for the global carbon-climate feedbacks”, GEOPHYSICAL RESEARCH LETTERS, VOL. 36, 2009 22. Boer G.J et al, “Temperature and concentration feedbacks in the carbon cycle” GEOPHYSICAL RESEARCH LETTERS, VOL. 36, 2009 23. de Boera H. J. et al “Climate forcing due to optimization of maximal leaf conductance in subtropical vegetation under rising CO2” PNAS, Jan 2011 24. C Yi et al “Climate control of terrestrial carbon exchange across biomes and continents” Environ. Res. Lett. 5 (2010) 25. Canadell J.C. “Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks” PNAS , November 2007 26. Harvey L.D.D. et al, Convention on Climate Change as a function of the climate sensitivity probability distribution function, Environ. Res. Lett. 2 (2007) 27. England M.H. et al. “Constraining future greenhouse gas emissions by a cumulative target” PNAS, September 2009 28. Azar C. et al, “The feasibility of low CO2 concentration targets and the role of bio-energy with carbon capture and storage (BECCS)”, Climatic Change (2010) 29. Anderson B et al, “Beyond ‘dangerous’ climate change: emission scenarios for a new world” Phil. Trans. R. Soc. A (2011) 30. Arora V.K. et al, “Carbon emission limits required to satisfy future representative concentration pathways of greenhouse gases”, Geophys. Res. Lett., 2011 31. Kurz et al, “Risk of natural disturbances makes future contribution of Canada’s forests to the global carbon cycle highly uncertain”, PNAS, 2008 32. Ramanathan et al, “Global and regional climate changes due to black carbon”, Nature Geoscience, 2008 33. Wild M., “Global dimming and brightening: A review” JOURNAL OF GEOPHYSICAL RESEARCH, 2010 34. Wild, M et al, “Global dimming and brightening: An update beyond 2000”, J. Geophys. Res, 2009 35. Sutton M.A. The European Nitrogen Assessment, 2011 36. Jan de Boer H. “Climate forcing due to optimization of maximal leaf conductance in subtropical vegetation under rising CO2”, PNAS, Early Edition, Jan 2011 37. Arneth A et al, “Terrestrial biogeochemical feedbacks in the climate system” Nature Geoscience, VOL 3, AUGUST 2010 38. Cao L & Caldeira K. “Atmospheric carbon dioxide removal: long-term consequences and commitment.” Environ. Res. Lett. 2011 39. Lacis A.A. et al, Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature, Science 2010 40. Barbero, L et al, “Importance of water mass formation regions for the air-sea CO2 flux estimate in the Southern Ocean”, Global Biogeochem. Cycles, 25, 2011 41. Schuster, U. et al. “A variable and decreasing sink for atmospheric CO2 in the North Atlantic” J. Geophys. Res. 2007 42. Jackson J.B.C. “The future of the oceans past”, Phil. Trans. R. Soc. B , 2010 43. Cai W-J et al, “Decrease in the CO2 Uptake Capacity in an Ice-Free Arctic Ocean Basin”, Science, Vol.329, July 2010 44. Boyce D.G. “Global phytoplankton decline over the past century”, Nature, July 2010 45. Zhao M. et al, “Drought-Induced Reduction in Global Terrestrial Net Primary Production from 2000 Through 2009”, SCIENCE 2010 46. Kerr . R. “Global Warming Is Changing the World” SCIENCE 2007 47. McNamara J.P. , “Arctic Landscapes in Transition: Responses to Thawing Permafrost” Eos,June 2010 In the seriesof papers above it becomes quite clear the CO2 is not going fall rapdily after even a total stopping of Co2 emissions and th epaper by Archer is useful but hten not really, for it assumes continued CO2 fertilization to large degrees and as it puts th etotal pulse of CO2 upfront it creates large atmospheric CO2 to Oceanic CO2 gradients pushing CO2 into the ocean at far greater rates than be expected now. Also I woudl suggest that you consdier further the scale of nitrogen fertilization response w ehave had since the 50's, increaseing the land sink and the oceans sink as the nitrogen a spercolated throughout the whole environment, and then of coruse looking at the Archer data even more closely ~50-60% of the CO2 remian in the atmoshpere for ~200years, and the CO2 models used doesn't really account for nutrient deprivation that well, no accoun tof permafrost releases, no accoun tof the increasing SH westerlies upwelling, no accounting for the increasing wetlands were getting, no accounting for the severity of droughts we are having, no accounting for the facts that from the face trials the CO2 fertilizatione ffect is short lived, no accounting for the removal of nitrogen fertilization as an urgent neccessity, no accounti9ng for the reducing sinks in the S. Ocean, North Atlantic, Off Japan for some reason, the loss of Phytoplankton, the increasing forest fires, the fact the Canada has become a carbon source, as have the tropics,no accounting for the facts that as the CO2 falls the sinks will re-relase the carbon they have stored,no accounting for the rise in CO2 as the world warms from oceanic sources and no accounting for the large scale biodiversity losses that are being witnessed that simplify eco-system and reduce carbon storage. All the aside an dwhy I mentioned the albedo effect, it is now clear that when ther eis ice on this planet th eeffective CO2 forcing is doubled, and keep in mind the arctic summer ice was 7million km2 recently, tha tis larger than the laurentide ice sheet and the water is darm blue compare dthe lighter land beneath the ice, meanign the albedo effect of a melting sea at the pole is considerable and quick... Then back to PETM when CS is higher than 3oC with the latest CO2 proxies by some way, nearer 7C, and then consider that again that the Pliocene was 3-5C warmer at 350ppm. And I'm sorry but to suggest that a trillion tonnes of carbon is in anyway safe, especially considering the major weather events and ice melt we all already having seems intellectual denial to me of the real situation..we don't have any room to put more CO2 into the atmosphere indeed if we don't start taking it out, and somehow increase carbon uptake from into the sinks to get the 350ppm then times will be interesting, although the scale of the problem to get to 350ppm is daunting indeed, for using even a simple CO2 with sinks that say high, to get to 350ppm means a 400ppm peak by 2017 and carbon sequestration from that point.
58315. sidd at 07:51 AM on 5 June 2012
       New research from last week 22/2012
       The Rignot paper is quite interesting. A result I had not expected is that basal sliding dominates. sidd
58316. Bernard J. at 23:48 PM on 4 June 2012
       Ian Plimer Pens Aussie Geologist Gish Gallop #2 of the Week
       Regarding Dale's claim at #6 about being retrenched, I did the obvious thing and emailed SCA. I'll pass on any answer that I might receive.
58317. Tom Curtis at 22:47 PM on 4 June 2012
       Ian Plimer Pens Aussie Geologist Gish Gallop #2 of the Week
       Dale @6, it's rather odd that I haven't heard about these retrenchments based on a tax that hasn't even been implemented yet. Even odder that there is no mention of them that can be found on a google search. Oddest of all is that while SCA Hygiene Australia did release a press release saying that a Federal Government decision could cost "thousands of jobs", the decision they were worried about was "the removal of dumping duties on rolls of toilet paper imported from Indonesia and China", with no mention of the Carbon Tax at all. Indeed, the terms "Carbon", "Tax", "global" and "warming" cannot be found by google search on the SCA site at all. In short, Dale, your story does not wash.
58318. Dale at 21:43 PM on 4 June 2012
       Ian Plimer Pens Aussie Geologist Gish Gallop #2 of the Week
       Can someone please call my old boss and tell him he didn't need to retrench me and heaps of others due to the carbon tax? A calculated rise of $9.3 million due to the carbon tax had to be recouped somehow. Oh, I used to work for SCA Hygiene Australasia, heavy energy and transportation users. Thanks.
58319. CBDunkerson at 21:21 PM on 4 June 2012
       Lessons from Past Predictions: Hansen 1981
       Curiousd, at 2 ppm per year, a 360 ppm starting point, and a 560 ppm target (two times the historical ~280 ppm amount) it would take (560 - 360) / 2 = 100 years (i.e. 2100) to reach double the historical CO2 level. To double again to 1120 ppm it would then take another 280 years if the 2 ppm increase per year held constant. I'm not sure how you are getting the 116 years figure (among other things it seems to assume annual increase remains a constant percentage of the accumulated total... which contradicts your own statement of a 2 ppm constant increase), but even if it were correct it could not then simply be extrapolated to another 116 years to forecast another doubling of CO2 levels as you indicate. If the rate of increase remains constant then the time required to double that atmospheric CO2 level also doubles. All that being said, the rate of atmospheric increase has not been constant. In the 1990s it was a bit below 2 ppm per year and it is now a bit above. However, this rate of acceleration is largely dependent on levels of human fossil fuel use and thus predictions of what it will be a century out are little more than guesswork.
58320. curiousd at 21:02 PM on 4 June 2012
       Lessons from Past Predictions: Hansen 1981
       Hi again Tom Curtis, I should also say that we do teach - say in talking about multiplying bacteria - that N = N1 x 2^(t/d.t.), d.t. is doubling time (You cannot use the e base with these folks for obvious reasons). But now I can say that there is an analogous expression that applies to something climate scientists call the climate sensitivity and the expression is C= C1 x 2^( T increase eventual/ T climate sensitivity). However - T increase eventual is indeed eventual - there is a fast reacting and slow reacting component. All this gives me a handle to incorporate and connect the climate sensitivity concept into the lecture on exponential growth, population growth, demographic transition, and so on then ask problems like the one I put into post 25.
58321. curiousd at 17:49 PM on 4 June 2012
       Lessons from Past Predictions: Hansen 1981
       Hi Tom Curtis, Say you are teaching this stuff to people who are paranoid of even simple algebra, and have been dragged kicking and screaming into a situation where they have to learn some math and physics to graduate. If they are to be tortured by math and physics anyway might as well give them problems like this: From Mona Loa data the annual growth of CO2 in the decade 2000 - 2010 is reasonably constant and averages about 2 ppm/year. The concentration of CO2 in the atmosphere in 2000 was about 360 ppm. (a) If present growth rates of CO2 continue, what is the "doubling time" in years for CO2? Standard rule of thumb for non scientists with math paranoia: D.T. = 70/ % increase. They would struggle to figure out what % increase 2 out of 360 was, but about half the class would do it correctly and get 116 years. (b) Climatologists have a parameter they call the "Climate Sensitivity" which is the temperature increase that is eventually guaranteed for a doubling of CO2. It could perhaps also be called the "doubling temperature." What would the eventual increase expected in world temperature that would result from 232 years of CO2 growth at the rate of the 2000 - 2019 decade? This is two doubling times of growth, which result in two doubling temperatures or an eventual guaranteed increase of 5.6 degrees C I would then ask them to compute the equivalent change in degrees F and here I would get really crazy answers from about half the class which I would need to adjust.
58322. Neven at 16:38 PM on 4 June 2012
       Toxic mercury, accumulating in the Arctic, springs from a hidden source
       Another source of mercury in the Arctic is so-called bromine explosions (in this blog post on Arctic pollution): Drastic reductions in Arctic sea ice in the last decade may be intensifying the chemical release of bromine into the atmosphere, resulting in ground-level ozone depletion and the deposit of toxic mercury in the Arctic, according to a new NASA-led study. The connection between changes in the Arctic Ocean's ice cover and bromine chemical processes is determined by the interaction between the salt in sea ice, frigid temperatures and sunlight. When these mix, the salty ice releases bromine into the air and starts a cascade of chemical reactions called a "bromine explosion." These reactions rapidly create more molecules of bromine monoxide in the atmosphere. Bromine then reacts with a gaseous form of mercury, turning it into a pollutant that falls to Earth's surface. Read more here.
58323. john byatt at 16:24 PM on 4 June 2012
       2012 SkS Weekly Digest #22
       The QLD minister for Climate Change Science&Policy confirmed today what had been obvious to most of us already, he is a sceptic. http://www.abc.net.au/worldtoday/content/2012/s3517410.htm
58324. adelady at 14:56 PM on 4 June 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       @40 "I’m simply not prepared to rely on models as much as others are so prepared. I’ve had a little to do with them over time, and recognise their value and risks. Does that address your question?" Recognising 'their value and risks' is what scientists themselves do. If you read journal papers or other commentaries and discussions by climate scientists, they're absolutely open about the specific purposes or limitations of various models and model components and the projects based on them. You really do need to be more specific. Do you mean that you think that the failure to predict the collapse of Arctic sea ice could be related to the limitations of the OHC modelling underlying the earlier projections of a slower decline? Or some other specific problem in lining up observed data and modelled projections? Or are you just nervous about models because they're models?
58325. scaddenp at 14:16 PM on 4 June 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       "Does that address your question?" It isnt a critical enough approach for my tastes. "Reasonable" can mean logically sound or it can mean say suggesting a middle ground on say sensitivity or simply, confirming my prejudices. A question like "are current temperatures consistent with the published science" has a yes/no unequivocal answer. The first step would be to check what the science actually says. (Eg one model result would be Keenlyside 2008 - so far not that cool). Wouldnt it be nice if the science was collated and evaluated in one place? That is what IPCC does - have you actually read the IPCC WG1. What are your ways of evaluating the trustworthiness of sources? The statements of all the science academies of the world doesnt convince you, so what matters? Do you prefer peer-reviewed papers or is fossil-fuel funded disinformation worthy of equal consideration? Oh and by the way, we depend on GCM models for constraining answers to questions like "what would 500ppm of CO2 do to the climate" in numerical terms but we dont need models to show the world is warming or that increasing GHG concentrations in the atmosphere causes warming. "Public statements" are not science. Worse they are often just sound bites selected by the media. Is it from a press-release accompanying a published paper or just someone's opinion. As with my point above - check with the source if you dont trust the speaker but its not science unless it is based on peer-reviewed publications. As to the response to Eric, my point was that you will have to adjust to high petroleum prices no matter what. You can do it now with bumping carbon tax and like, and help slow climate change; or you will do later when also facing climate problems. Its not primarily a climate issue. Hell, I would be happy if petroleum was untouched (my livelihood) so long as not another coal-powered station was built. I would be horrified if it was suggested that the plight of the "fuel poor" was a reason for delaying action on climate. Its a bit rich worrying about those who can even afford to buy fuel at relatively low prices when climate change will bite the truly poor through drought and salt-invasion. I understood Eric to mean that you have to put in measures additional to carbon tax to ensure fairness which the US is well able to afford.
58326. Chris G at 13:19 PM on 4 June 2012
       Modelling the Apocalypse
       Tom, I think I should have digested your last paragraph a bit more before commenting. Surely not an entirely accurate depiction of what you wrote, but maybe not too far off: As the upwelling of the ocean is helping keep the surface cool, the downwelling is helping to extract/sequester CO2 from the atmosphere. The maximum temp reached is quite a bit lower than what would be expected only from the maximum CO2 level. Here's to hoping you are right.
58327. Tom Curtis at 12:50 PM on 4 June 2012
       Lessons from Past Predictions: Hansen 1981
       curiousd @22, you can partially eliminate that problem, and conditions (b) and (c) in my 23 by calculating the Transient Climate Response, which is about 2/3rds of the ECR (with a large uncertainty). However, the remainder of my points from my 23 would still stand.
58328. Tom Curtis at 12:44 PM on 4 June 2012
       Lessons from Past Predictions: Hansen 1981
       curiousd @21, I believe your mathematics is correct (though maths is not my strong suite). What is absent is an awareness of the physics. Your formula would be useful to predict the change in CO2 concentration if: a) We used the measured climatology (>29 year mean) of Global Mean Surface Temperature for two periods, commencing t1 and t2 to determine dT; b) t1 and t2 where sufficiently far apart in time for the Earth to reach an equilibrium response to a change in forcing; c) t2 was sufficiently long after the last change in CO2 concentration for the Earth to have reached the equilibrium climate response; and d) Change in CO2 levels where the only change in forcing between t1 and t2. For conditions (b) and (c), a sufficient period is certainly not less than a century, and may be considerably longer. Conditions (a) through (c) when we compare data from paleoclimatology with each other, or to present values. Condition (d) has probably never been satisfied on Earth, and is certainly not being currently satisfied. The standard formulas are useful because we can calculate the change in forcing for a variety of forcings, sum them and then calculate to a first approximation the expected Equilibrium Climate Response. Being more accurate, we would apply a weighting to each forcing separately to allow for the fact that different forcings have slightly different feedback responses due to differences in geographical, vertical and temporal distribution. By definition, the weighting of CO2 = 1. (We could of course, define any other forcing as having a weighting of 1 instead, simply by varying the constant in the second equation.) So, given the above, my question is, where are you going with your equation?
58329. curiousd at 12:25 PM on 4 June 2012
       Lessons from Past Predictions: Hansen 1981
       OOPS! No my last sentence beginning "And" is wrong above. Because the dT contains rapid response components and long response components. I was forgetting about that important point.
58330. curiousd at 12:10 PM on 4 June 2012
       Lessons from Past Predictions: Hansen 1981
       Thanks Tom Curtis. Huh! Then Equate the dFs in 1 and 2 You get dT/0.75 = ln(C2/C1)x 5.35 dT / 4.01= ln (C2/C1) e^(dT/4.01)= C2/C1 = 2^ (dT/X) ; set c2/c1 = 2 and what is unknown X? X = 2.8 Then: equivalently (C2/C1) = e ^ (dT/4.01) (C2/C1) = 2 ^ (dT/2.8) By getting rid of the dF you get that (C2/C1) depends exponentially on dT and the formula with the 2 base shows the doubling temperature (climate constant)perhaps more clearly. So.....this way one can get climate constant into the "exponential growth" section of a basic course. And an exponential growth versus time in CO2 yields a linear growth versus time in dT.
58331. JasonB at 11:42 AM on 4 June 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       Peter, The paper Chris G linked to simply says that even smart people can employ illogical thought processes. This is self-evidently true, and this site documents many examples. This does not mean, however, that their conclusions are worthy of respect. Invariably there is a flaw in their argument that invalidates their conclusion, which for whatever reason they seem incapable of appreciating, and I'm yet to see a single example that does not suffer from this. My solution to conflicting commentary is to see if the arguments stand up to scrutiny and are supported by the evidence. Almost invariably the commentary that agrees with the mainstream scientific position passes this test -- and on the few occasions when it doesn't, it's almost always the mainstream scientific community that points it out -- while the commentary that does not agree with mainstream views also almost invariably fails the test, often in surprisingly obvious ways. It's hard to put the claims that you have relied on to form your "agnostic" position to that test since you seem reluctant to reveal them, which in itself is surprising. If I had "well-reasoned" arguments from both sides that made it difficult for me to decide who is right, the first thing I'd do is search for existing responses to each argument from both sides (and, obviously, SkS is an invaluable resource in that regard) and, if a response did not address the argument adequately, I would say so in the appropriate location (e.g. the comment thread of one of the posts here). If I could not find an existing response, then I'd be more than happy to bring it to people's attention -- who knows, maybe there is a paper out there that SkS has not addressed that would affect people's perception of the science? Perhaps there is some critical observational data that does not fit with the prevailing scientific theory that nobody here has noticed yet? Hiding it under a bushel doesn't seem to do anybody any good. If they "are all probably refuted on this site at least", why not at least check to see if that is the case? Either the refutation fails to convince you, in which case you can say so and help improve the refutation (or point out its flaw), or it does convince you and you can stop relying on information that is demonstrably false. "What’s the point of that?" So you can make decisions based on sound information, or, if you are correct, so you can help others to make decisions based on sound information. Both seem like worthwhile goals.
58332. adelady at 11:06 AM on 4 June 2012
       2012 SkS Weekly Digest #22
       Piling on? I think it's good for casual readers to see that some of the guff that gets posted is promptly and easily refuted by just about any commenter. However ...... If such an exchange continues (some of these people can be quite persistent in ignoring or denying scientific guidance), it can be worthwhile for moderators to intervene and control responses which need to get into seriously technical explication and/or pin down the flailing around of someone who's out of their depth and doesn't know it yet. No easy black and white answer I fear. I'm pretty happy with the judgement of moderators in applying the Comments policy. I doubt there's a concise form of wording available to include such 'exercise of judgement' criteria in a simple guideline.
58333. Tom Curtis at 08:50 AM on 4 June 2012
       Modelling the Apocalypse
       Chris G @16, I disagree. The time taken for the system to reach the Equilibrium Climate Response (ECR) is likely to be greater than 80 years, and may be over 200. Further, in most models of the carbon cycle, the initial reduction in CO2 is rapid, declining to about 60% (range of about 45 to 80%) within 100 years. That means the initial temperature peak is likely to be equivalent to 45 to 80% of the ECR for the peak CO2 levels, after the negative effects of aerosol forcings are removed. Curiously, the ratio of Transient Climate Response to ECR across AR4 climate models is 0.4-0.8, with a median value 0.55 (Mean = 0.544) (see histogram on third slide)which indicates the ECR to the declining CO2 levels is roughly equivalent to the TCR of the peak level. Clearly, the exact behaviour will depend on the exact values of the TCR, ECR, relaxation time to oceanic equilibrium for CO2, and relaxation time to ECR, all of which are uncertain. Nor can we expect an exactly linear response over the first century after ceasing GHG emissions. But nor should we expect the variation from the temperature leveling significantly beyond that which would occur from leveling plus natural variability. I consider these facts good news. They mean we have longer to cut GHG emissions to effectively zero before passing the 2 degree C "guard rail" than is often supposed. Unfortunately that extra time only means that we might still make that target if we start cutting emissions radically now, rather than already being beyond that point.
58334. RabbeZ at 08:07 AM on 4 June 2012
       Toxic mercury, accumulating in the Arctic, springs from a hidden source
       Yes, a rather large portion (25% ??) of the global mercury cycle is natural (volcanic). http://www.chem.unep.ch/mercury/report/chapter6.htm and http://www.sciencedaily.com/releases/2008/06/080629081932.htm (from some newer papers i have understood that there is still some small controversy about the budget, but thereabouts). Seems to be a very interesting and important paper, shame its behind paywall. Nice that SkS highlighted this topic.
58335. Chris G at 07:24 AM on 4 June 2012
       Modelling the Apocalypse
       Peter42, I thought the polarization paper was interesting because it steps away from the trap of thinking that people that don't come to the same conclusions as you must not be as smart. Smart people often come to different conclusions, and sometimes this in despite a preponderance of evidence on one side. The mind is not deterministic like a computer, and Spock-like rationality is not a trait many people have. Looking at the "Working out climate sensitivity" post (linked above), I tend to agree with mostly with Ranyl's conclusions, even if I don't agree with all points. Ice albedo feedback is already figured in to paleo studies of CO2 sensitivity; any additional CO2 feedbacks change the CO2 level, on which the temperature sensitivity is based. The climate sensitivity estimates for temp record and last millennium in Figure 1 indicate to me that the earth is a bit behind equilibrium with current levels of CO2. Those two are lower than all the others. Geoengineering: I believe it will be attempted, and I believe it will be messy, as Glenn says. Thorium: Yes, for the points mentioned. Sooner or later though, regardless of energy source and climate, population will have to level off simply because of finite resources. My two cents: Climate change will transform a leveling off into a bottleneck. Tom C, I don't think your quote from David Archer that gives a 2-20 century ocean equilibrium timeframe supports any model that shows a temperature leveling within 100 years. It is a bit tricky because a temperature equilibrium could occur prior to an ocean CO2 sat equilibrium as the ocean draws down atmospheric CO2, which is why I'm saying 100 years rather than extending out to the 200-2000 window.
58336. kampmannpeine at 06:14 AM on 4 June 2012
       Toxic mercury, accumulating in the Arctic, springs from a hidden source
       it seems there are even more consequences of climate change than rising temperature, rising sea level, rising acidity ... where will we end??? Hope there is a natural explanation!
58337. Tom Curtis at 04:49 AM on 4 June 2012
       Lessons from Past Predictions: Hansen 1981
       curiousd @18, the standard formulas are: 1) dF= ln(C2/C1)*5.35 2) dT=0.75*dF The margin of error for the first constant is +/- 10%. That for the second is approximately 0.55-1.1 dF is change in forcing in W/m^2, dT is change in temperature in degrees Kelvin, C2 and C1 are as per your definition. Clearly these formulas are simple approximations. In particular, the first formula cannot be valid for very low atmospheric concentrations or else forcing would be infinite. It is, however, approximately accurate for the range of CO2 concentrations that may have been experience on Earth over the last 600,000 years (150-8000 ppmv) and therefore also over the range of CO2 concentrations humans are likely to produce in the atmosphere.
58338. curiousd at 04:38 AM on 4 June 2012
       Lessons from Past Predictions: Hansen 1981
       Tank you Dana. If you don't mind another question, from other answers to my questions I gather that no matter what the CO2 concentration, doubling the CO2 produces the same change in temperature. I think this means that C2 = C1 x 2^(delta T1/3) if 3 is the "climate sensitivity" as is called in your field. But so far I have not come across this expression. Am I correct here? In other words if delta T = 3 , C2/C1 = 2. If in the future C3/C2 = 2 then C3 = 4C1 so that C3 = C1 x 2^(2 deltaT1/3). In other words, CO2 concentration varies exponentially with temperature change. Do I have this correct?
58339. Tom Curtis at 03:41 AM on 4 June 2012
       Modelling the Apocalypse
       ranyl @14, your view is far too pessimistic. Modelling studies have consistently shown that a cessation of CO2 emissions results in the rapid draw down of CO2 concentrations as CO2 partial pressure equilibriates between surface and deep layers of the ocean. According to the most recent such study by David Archer (PDF):

       "The models agree that 20–35% of the CO2 remains in the atmosphere after equilibration with the ocean (2–20 centuries). Neutralization byCaCO3 draws the airborne fraction down further on timescales of 3 to 7 kyr."

       Below are the model results for a 1000 Petagram pulse (1 trillion tonne) Carbon pulse of CO2, an amount widely recognized as a upper limit on cumulative emissions to avoid greater than 2 degrees C temperature increase above pre-industrial levels: As can be seen below (fig 1a, blue line), Matthew's model is, if anything, pessimistic on these grounds. That is partly because of the decay of other,short lived green house gases to CO2, and further outgassing from the surface ocean as ocean temperatures rise. However, it probably also reflects a slower draw down of CO2 than is typical of other models: (Source) The consequences I would expect from a complete cessation of CO2 emissions would be an approach to the equilibrium temperature change of the remnant of CO2 in the atmosphere within a century or so, followed by a slow rise to the Earth System Response as the effect of changing albedo due to melting ice sheets becomes noticable. Ball parked as a funtion of the Transient Climate Response to the peak CO2 concentration, that would represent 1.5 (ratio of Equilbrium response to TCR) * 0.33 (increased CO2 concentration above preindustrial levels after equilibriation with the ocean) * 1.5 (ratio of Earth System Response to Equilibrium Climate Response). Very roughly, that represents 0.75 of the peak temperature reached, but could be only half of that, or equal depending on the precise value of fairly uncertain figures. Matthew's results are certainly plausible, although on the pessimistic side of that range.
58340. bath_ed at 03:24 AM on 4 June 2012
       In Search Of: Himalayan Ice Loss
       While Justin's comment at 6 is almost comically flawed, I don't think it falls into the strict category of not even wrong as its premise (that the Himalayas are still rising due to plate tectonics) is at least correct. A not even wrong idea would be one based on a premise that is already known to be wrong, such as seeking to explain the melting of the Himalayan glaciers by some mechanism that involves a flat Earth. Nevertheless, climate science appears to attract such bizarre objections, in particular those that confuse processes that have a great magnitude but unfold so slowly that they cannot explain recent changes. It is as if one were to explain a London-New York passenger flight being half an hour later than usual by by appealing to the fact that the Atlantic is getting wider due to plate tectonics.
58341. Tristan at 01:34 AM on 4 June 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       Peter In what way is this post unreasonable? What further evidence do you require to accept the post's veracity?
58342. michael sweet at 00:09 AM on 4 June 2012
       Richard Alley's Air Force Ostrich
       Justin, In reviewing your posts on this thread I see that you have not made or referred to a single cogent argument in support of your position. You just make assertions of what you think is correct. Since Skeptical Science is a data based web site you need to support arguments with data, not rhetoric. Note how Tom and Muoncounter supplied data to support their positions. If you want to score points on people who are "easy targets" go back to WUWT where they like that type of ignorant word play. If you want to learn more you will find that you come across better if you ask questions instead of making rude comments. If you had said "I do not understand how the picture of the helicopter relates to Global Warming research" Tom could have made the same points and you would look reasonable. There are currently several posters who ask these questions. In post 11 you said you would present a cogent argument in support of your position. Now is the time. Please support it with data and not just empty hand waving. If you cannot support your claims with data I suggest you go to the home page and read the "Start Here" button. Ask questions on the relevant thread.
58343. Michael.M at 20:10 PM on 3 June 2012
       It's not bad
       New Research, showing decrease in fertility: "...Our findings imply that climate change affects aboveground–belowground interactions through changes in nutrient availability." Interactions between above- and belowground organisms modified in climate change experiments Stevnbak et al., Nature Climate Change(2012) doi:10.1038/nclimate1544
58344. ranyl at 19:04 PM on 3 June 2012
       Modelling the Apocalypse
       "Constant atmospheric carbon dioxide concentrations lead to continued warming for many centuries, whereas the elimination of carbon dioxide emissions leads to approximately stable or decreasing global temperature." This is the caption from the blue line graph in the Nat.Geo publication, and this seems rather to totally unrealistic to me purely on the GHG front. Why? Well from the latest carbon models if CO2 emissions stopped today the fall atmospheric CO2 concentrations aren't falling by much for 1000's of years and as they do fall CO2 stored in the sinks is re-released delaying the fall even further, so stopping emissions today won't see any drastic fall in GHG in the atmosphere in the short term. The rate of drawn down from the recent models is ~0.2ppm per year so a fall of 20ppm in 100years, hardly removing the heater, and that doesn't take many things into account either...e.g. permafrost melt. Also what about the CO2 that is always released when the earth warms up, ~14ppm a 1C, what has happened to that? And does the albedo feedback just stop? Snow lines are moving north, the arctic is melting (~same size of the N.America Ice sheets when they were present), permaforst is melthing another source of CO2, the CO2 fertilization effect will equalise (see face trials it don't last long anyway) and decrease as soon as CO2 falls at all. Then there is the stopping of the fertilizer affects from man's agricultural practices which as been boosting the land CO2 sink considerably (this would all be lost actualy releasing CO2 as things equilibriated)and overall causing a slight cooling due to this and NO, methane and ozone interactions, and then of course there is the sudden lack of dimming as said which will be significant especially considering SO2 atmospheric concentration haven't actualy fallen world wide since 1980 and have started to rise again in th elast few years as India and China industrialise and finally ther eis the release of methane from melts permafrost and increasing wetlands. And what about the warming already stored in the oceans, which most people put at another 0.5-7C to come? According to Hansen the earth heats up 6-80% of its full potential in 100years then the additional 20% takes 1000years or so, so how can warming stop immediately, especially as the heater isn't turned off by stopping emissions it is stopped but reducing atmospheric CO2 concentrations! And lets no forget the CFC's. HFC's. NF3 additional GHJG which last for eons and eons. Sorry but I find it totally incredulous that zero CO2 emissions from tomorrow would just stop warming in its tracks, and would suspect the model being used is grossly overestimating CO2 drawn down and not taking the stored oceansic heat content into context. Bottom line is to prevent 2C we don't just need to stop emissions we need to actively build-up land and oceanic sinks to draw CO2 out of the atmosphere. Remember which ever you look at it, when the sun was dimmer than today, the world's geography basicaly the same, a CO2 of 350ppm cuased the world to be 3-5C hotter, so how is stopping at 400ppm going to stop us warming to this full potential??? SO basically overall saying stopping emission will halt warming is not realistic and actually gives false hope. We need to actively get to 350ppm by 2100, and the only way to do that is to stop all emissions for sure and by 2017!!!!!!, and then actively remove CO2 to get to 350ppm by 2100, which if the early Pliocene data is correct still means 1.8-2.4C by 2100.....in Hansens lastests papers this is more like 1.4-1.6C, but he has th eearly Pliocene only 2oC warmer as he uses deep ocean temepratures with a conversion factor whereas all other studies have 3-5C and CO2 concentrations of ~350ppm, upper limit 400ppm but with more specific CO2 proxies only 325ppm.... Sobbering, but entirely possible, just take everyone to realise it and also realise that 2C isn't dangerous because of potential tipping points but because the climatic shifts and severe weather events, drought s and floods have no mercy on crops or water availability! and a direct threat to us all not just those in other parts of the world.
58345. Peter42 at 19:03 PM on 3 June 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       To scaddenp @33 & #36, (13.40 pm and 13.51 pm 3 June 2012): Thank you for your courteous response, and for taking the time to look over the Chris-G paper. I agree very much that conformance to group values is indeed not the way to guide our future. One implication is that one must be prepared to stand up and express one’s view, regardless of its acceptability to the group, a challenge for climate change sites of every persuasion. I am encouraged by your comments. How do I deal with conflicting commentary? Simple question, difficult answer. The hard part is not to be upset by any emotional overtones – my own, and others. Try to understand where they’re coming from. Test the reasonableness. And sometimes just wait, for more evidence. I’ve had to do this often in my life – why should I approach this very important question differently? I’m simply not prepared to rely on models as much as others are so prepared. I’ve had a little to do with them over time, and recognise their value and risks. Does that address your question? Concerning your second paragraph, many who have made public statements about the risks of climate change have not noted sufficiently the assumptions and limitations. I really haven’t enough time to sit down and carefully document them. I'm sure they can be found on other sites. I have a life as well, as I know you do. I don’t think the problem lies primarily with the scientific papers, but I do think there have been a number of occasions when public statements referencing those papers have not reflected the original scientists’ assumptions and reservations. May I make a comment concerning your response to Eric (#35)? Eric is clearly in a better position to confirm this, but I have lived in the USA at an earlier time (not in Virginia, but Michigan), and I can imagine that many of the people who have to travel some distances to find work, have dependent children at school, and other kinds of local ties, quite apart from financial constraints, that make relocation quite difficult. People such as those of us who have the facility and luxury of time to meet on this site, are generally far better educated and qualified to find jobs that are both convenient and relatively sustainable (in the sense you note). This is part of the balancing in viewpoint that I find useful.
58346. funglestrumpet at 18:41 PM on 3 June 2012
       Modelling the Apocalypse
       PhilMorris @ 8 I couldn't agree more, Thorium nuclear reactors are an excellent way to reduce carbon emissions while maintaining our current standard of living, which is something that many will not sacrifice if they can put off the nasty effects of Climate Change untill later, much later. Let's face it, there are a lot of questions raised about just how good renewables really are. This link (if it works - never put one in before!) takes you to a TED talk on the matter.
58347. Glenn Tamblyn at 17:43 PM on 3 June 2012
       Modelling the Apocalypse
       Aerosols from China, India and similar countries are certainly a cooling factor at the moment but we don't have good enough data on their distribution and what the mix of aerosol types is to quantify the effect that well. Infortunately we haven't been able to successfully launch a satellite to start measuring. Current moves to gas instead of coal in many parts of the world may have some interesting implications if the scale keeps ramping up, especially if gas is actually replacing existing coal plant. Gas produces less CO2 than Coal for the same amount of net energy produced. So a modest positive in reducing emissions. But Gas burns pretty clean, without generating the same levels of aerosols. So it would contribute to drawing down aerosol levels in the atmosphere and thus removing some of their masking cooling effect and revealing more warming. Personally, I think that is a positive occurance. Not that there is more warming, because that warming is already locked in, it will be revealed eventually when we stop burning fossil fuels. Rather the more the eventual warming occurs sooner rather than later, the more that can help influence public opinion towards action. Ultimately it is the eventual warming that is the issue. But action seems to need warming now as the basis for action. Kate's post also highlights one of the problems with GeoEngineered mitigation of AGW. Even if GeoEngineering results in mitigation of global average temperatures, there will still be substantial regional climate changes. This is potentially a legal (and even military) mess. Country A unilaterally starts some GeoEngineering activity, injection of aerosols into the atmosphere being an obvious example. However, even though A's efforts do bring about a net positive benefit globally, County B happens to be a big loser in this, with negative climate changes being dumped on their region. What does Country B do? Just live with it? International legal action against A? Military strikes against A's aerosol dispersal infra-structure? How does B weigh up its responsibilities to it's own citizens vs it's responsibilities to the world as a whole Messy!
58348. scaddenp at 17:32 PM on 3 June 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       "However, it is indeed possible to identify some earlier statements that have been made about predicted climate change effects, which so far have not eventuated." Hmm, to which papers are these predictions that refer to? Some early statements had climate sensitivity too high (for well-understood reasons), but the papers noted these assumptions and limitations so are hardly "disproved" by data. I would still you like to describe your process for dealing with conflicting commentary. This seems to me to be the most constructive way to continue a discussion. The decision making outlined in the Chris-G nature paper (conformance to group values) is not what we want to guide our future.
58349. Peter42 at 15:51 PM on 3 June 2012
       IEA CO2 Emissions Update 2011 - the Good News and the Bad
       To scaddenp @33 & #36, (13.40 pm and 13.51 pm 3 June 2012): Thanks for the background (from yourself and others) on the use of “catastrophic” in this context; I now understand better how the term has been used derogatively, and as I’ve noted elsewhere, the terms “alarmist” and “denier” are similarly unhelpful. My apologies to all. On the data records, yes, I do read interpretations of the significance or otherwise of these records. However, it is indeed possible to identify some earlier statements that have been made about predicted climate change effects, which so far have not eventuated. I do accept that the latest official statements are those we should reference today, not yesterday’s. On the issue of assessing the significance or otherwise of flat or declining temperatures, I’ll read thoughtful analyses from both sides, and continue to note progressive observational data. To Sphaerica @37 (14.29 pm 3 June 2012): An interesting paper noted by Chris G @7 (5.24 am 3 June 2012) “Modelling the Apocalypse” discusses the point you make about differing views on global warming. Worth reading. The analysis included the educated. Are we to conclude they are all ill-motivated? Also, there is indeed at least one place between acceptance and disagreement on any issue – in a religious context, it is known as agnosticism. I see on sites supporting one side or the other, the tendency for like views to gather, with opposing views treated dismissively. That doesn’t help either side.
58350. dana1981 at 15:11 PM on 3 June 2012
       Lessons from Past Predictions: Hansen 1981
       Hi curiousd. I believe Figure 6 is a plot using Model 4, actually. If you look at the top of page 3 of the paper (page 959 in the journal), it says Model 4 has the climate sensitivity they're using of 2.8°C for doubled CO2. Prior to that they note that they didn't have enough knowledge at the time to include the vegetation feedback for Models 5 and 6, so 4 was advanced as they could get with reasonable confidence.

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