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Gilles at 02:07 AM on 4 March 2011Climate Sensitivity: The Skeptic Endgame
mucounter : I think the evidence is pretty well displayed on figure 2. I don't know any physical quantity whose measurements differing by a factor two or more would be said to "agree" , do you ? my point is that if a theory is not accurate, a "likelihood" estimate based on the number of models giving such and such value has no real signification. For obvious reasons : if I add "wrong" models to the sample, giving much higher o smaller sensitivity, the "likelihood" of all others, including the true one (if any), will decrease. Well that's kind of weird isn't it ? how can the validity of a true model decrease if I add BS to the sample ? so please tell me : how exactly is chosen the sample on which you compute this "likelihood" ? -
Kevin C at 01:09 AM on 4 March 2011Roy Spencer’s Great Blunder, Part 2
Thanks Dikran for pointing that out. In fact, the entire paragraph added little to the point I was making and will distract from it for some readers - my point would be improved by deleting it if you feel inclined. Sorry for the inconvenience. If I may expand: There's a huge can of worms concerning communication which I think needs discussing, and I'm not sure where the discussion should take place. I've barely begun to scratch the surface. Can I illustrate by some questions: 1. Who is SKS speaking to? How does that affect the form of communication SKS should adopt? (Has this question even been asked? Or did it happen the other way round: The form of communication - NPOV academic with lay summaries - was chosen and the resulting audience was a unplanned consequence.) 2. Who is Barry speaking to? To Roy Spencer, to people who have read his book, or to people who might encounter people who have read his book? How does that affect the form of communication? 3. Who are the contrarians and what are their motivations? How do we best communicate to different contrarian groups? Which groups are most accessible to persuasion? (As an illustration, communicating to someone who regards themselves as a rational skeptic who has made a reasoned rejection of a consensus view is very different to someone whose views are derived from a political ideology, or someone whose views are determined by the need to conform to a peer group. In the last case, changing someone's mind might destroy their social network - a hard challenge). There appears to be an active sociological and cultural anthropological academic literature on these issues. 5 mins with google pulled up these: http://www.stanford.edu/group/CCB/articles/Anderegg_ClimateConsensus_Report2009.pdf http://www.carleton.ca/isema/documents/editions/ISEMAFall2006.pdf#page=10 http://pus.sagepub.com/content/16/2/223.short I don't even know where to start, and if I were to do so the sociologists would rightly be laughing at me and whispering 'Dunning Kruger' to one another. What I'd really find useful is some articles, possibly be sociologies/social anthropologist writing in lay terms, on understanding who the different groups are skeptics are and how they are being so successful in communicating a message. Also what forms of communication are open to us and how to chose between them.Moderator Response: No problem, your mention was fine as it was only an illustrative aside. -
Eric (skeptic) at 00:53 AM on 4 March 2011Climate Sensitivity: The Skeptic Endgame
I believe that error bars and probability distributions can be misleading in the context of sensitivity. Looking at fig 3 in the Knutti paper, I see two lines of evidence: models and paleoclimate. The paleoclimate evidence has red boxes for "similar climate base state", IOW it doesn't apply to today's interglacial climate. An error bar or a probability distribution doesn't capture that fact, only the red box does. The second type of evidence is models, as discussed in the models section in the paper: "Different sensitivities in GCMs can be obtained by perturbing parameters affecting clouds, precipitation, convection, radiation, land surface and other processes". In the section Constraints from the Instrumental Period, the authors say that the tenperature response to fast forcings has a nonlinear response to climate sensitiity and thus can be only verified by validating the models. The model results form a "probability distribution" only in the narrow sense of a series of random runs. But perturbing parameters is not probabilistic, those perturbations are either correct or not. So a broader probability distribution or an error bar is simply not possible. -
damorbel at 00:49 AM on 4 March 20112nd law of thermodynamics contradicts greenhouse theory
Re #449 Sorry, the link doesn't work. refractive index -
thepoodlebites at 00:47 AM on 4 March 2011Ice age predicted in the 70s
#34 I'm just starting to review some of the relevant articles, W.S. Harley (1979) concludes "evidence of a change to a cooler regime has been found in the East Asia areas in each season except winter, in the Eastern North American area in winter, and in the Central Atlantic area in the spring and summer." And "no evidence of climatic warming is found."Moderator Response: [Dikran Marsupial] s/relevent/relevant/g -
muoncounter at 00:40 AM on 4 March 2011Climate Sensitivity: The Skeptic Endgame
"I say that when the models rather strongly disagree with each others" Perhaps its time for you provide some evidence rather than make unsubstantiated declarations: To which models do you refer? What exactly do you mean by 'strongly disagree'? Is that based on any form of significance test? Without such evidence, you lack credibility. "BTW, I never stated that ALL estimates were based on models." You gave that impression with your comment here. And you have adroitly shifted this discussion back to the subject of modeling more than once. It seems the form, if not the substance, of your commentary here is tending towards 'I disagree,' 'Oh really?' and 'Yes, and ... '. Surely there are more valuable ways to contribute. -
Bibliovermis at 00:26 AM on 4 March 2011Ice age predicted in the 70s
I decide to give them a second chance and push on past the Newsweek reference, and then past the Washington Times, New York Times, and Times Magazine references to find the 1975 NAS report on "Understanding Climate Change". That report did not make any predictions and the coming ice age discussed was several millenia out based on orbital parameter variation. -
Bibliovermis at 00:09 AM on 4 March 2011Ice age predicted in the 70s
Why even mention Newsweek when claiming to focus on peer-reviewed scientific research? They lost my respect by using that as the opening argument. -
Gilles at 23:42 PM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
Moderator : there is absolutely no accusation of anything. I was just asking what is written : do you think this new study will be considered as an almost definite answer to the question of climate sensitivity. BTW, I never stated that ALL estimates were based on models. Concerning Hansen's study, I will first ask a question : do you have an idea of the magnitude of the annual variation of solar forcing between June and December, due to Earth orbit eccentricity, and the corresponding annual modulation of the average temperature, which could be transcribed as a "sensitivity" (∆T/∆F) ?Moderator Response: [Dikran Marsupial] Speculation of what the IPCC may or may not write in the next AR is off-topic, and likely to end up in accusation/insinuation of bias etc. AFAICS there is no reason to suspect they will deviate from current practice of giving a survey of available results (c.f. Hockey stick sphagetti plot, which shows a variety of proxy constructions). Procede no further in that direction. -
thepoodlebites at 22:58 PM on 3 March 2011Ice age predicted in the 70s
Climate Depot's Factsheet on 1970s Coming 'Ice Age' Claims. I think that your 10% predicted cooling statistics need revision. It's a tad low don't ya think? These '70's papers were consistent with the global cooling theme that I was taught while taking college meteorology classes in 1980-1982. -
Tom Curtis at 22:55 PM on 3 March 2011Crux of a Core, Part 1b
Gilles @16, it is nonsense to suggest that anthropic forcings are hardly measurable in the first part of the 20th century. Forcings due to the green house effect are approximately constant for each doubling of concentration of the greenhouse effect. That means the 35 ppm increase in CO2 from approx 1850 to 1960 (12.5% increase) generates the same forcing as the 40 ppm increase from 1960 to 1990 (12.5% increase). So while the GHG forcing in the second half of the 20th century relative to the first half is larger than the forcing in the first half relative to the preindustrial era, it is not much larger. Deniers often misrepresent the findings of the IPCC that the warming in the first half of the 20th century cannot be unambiguously attributed anthropogenic causes as meaning anthropogenic causes were weak or non-existent at that time - again nonsense if not deliberate deceit. All the attribution result means is that the warming does not lie outside of the 95% confidence interval of natural forcings alone. Consistent with that, anthropogenic forcings have contributed around 40% forcing, with some combination of reduced volcanic activity and increased solar activity contributing the rest. In the second half of the twentieth century, volcanic activity has been high, and solar activity slightly reducing, so that natural forcings alone would lead us to expect a cooling planet. However, despite the fact that in the early twentieth century, substantial anhropogenic forcings worked with natural forcings to drive up temperature, while natural forcings worked against anthropogenic forcings as they drove up temperatures in the second half of the 2nd century, and contrary to your claims, the longest and steepest climb in temperatures in chart @7 is clearly in the instrumental record of the second half of the second century. You are entitled your own theories, but not your own facts. -
Kevin C at 19:20 PM on 3 March 2011Roy Spencer’s Great Blunder, Part 2
Barry: having read part 3 on your blog, I'd like to withdraw my comments on the tone. In the light of part 3, the tone of parts 1 and 2 makes a lot more sense to me. In retrospect, I now see the form you have adopted: It is a 'journey narrative'. Part 3 makes this obvious in that you document how you explore Spencer's ideas for yourself a step at a time and found them wanting. This is an extremely effective form of communication, especially to non-scientific and particularly post-modern audiences. As evidence, look at how many science documentaries are now personal narratives of how a scientist came to a particular understanding. It personalises the material and makes it easier to relate to. Evangelical Christians also often use this form - it is called 'sharing your testimony'. In addition to being an effective means of communication, it has another benefit that it is much harder to argue with personal experience than with evidence - not that that is a relevent concern in your case. If I were given the opportunity of explaining evolution to an audience of my fellow Christians, I would adopt the same form, describing my journey from a pure physics background into discovering molecular sequence data and what I could do with it. So actually, I think the form you have chosen perfectly fits your material. Maybe we should be looking for other elements of climate science we can communicate in this way - Tamino's anniversary rant about reproducing stuff for himself might provide some source material. It's a different mode of communication to that usually employed at SKS, but it is an effective one and one which had the potential to reach different audiences.Moderator Response: [Dikran Marsupial] While Kevin has legitimately mentioned evolution in passing, while discussing methods for communicating science, this should not be regarded as an invitation to discuss evolution or intelligent design etc., which is clearly off-topic. -
Gilles at 19:13 PM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
Sarah : do you think that the "new" Hansen value will be considered in the next AR as THE accurate determination of climate sensitivity, dismissing all the other ones, (something like the first accurate measurement of CMB by COBE), or just as one of the many contributions, among other ?Moderator Response: [Dikran Marsupial] The comments policy forbids accusations of dishonesty or conspiracy or politics etc. This post appears to heading in distinctly that direction Please stick strictly to the science and leave such issues for elsewhere. Sarah has provided you with an example of a determination of climate sensitivity that isn't based on modelling (addressing one of your concerns), that gives you something concrete as the basis for a more constructive discussion. -
les at 19:09 PM on 3 March 2011Crux of a Core, Part 1b
modes... I'm getting an error from garythompsons graphics link to ftp://webpages.charter.net/vostok%20plot.jpg which is requesting a password!Moderator Response: [DB] Thanks for bringing that to our attention. I was wondering why I was getting that prompt all of a sudden. -
Gilles at 19:06 PM on 3 March 2011Crux of a Core, Part 1b
7 NYJ : as far as i can see, in this graph, the PROXY (not instrumental but reconstructed) temperature raises only in the first part of the XXth century, when anthropic forcings are supposed to be hardly measurable, and stop climbing when anthropic forcings are supposed to become dominant. Any explanation for that ? about changing scales : why is it inappropriate to demonstrate a CORRELATION ? -
Tom Curtis at 18:27 PM on 3 March 2011Crux of a Core, Part 1b
Sorry, I missed pointing out that Bluemle et al cite Dansgaard et al. for the claim (p 69). As a further note, the GRIP data has a time resolution of only 200 years per data point at that period, so could not show a three data point variation in 80 years in any event. -
Tom Curtis at 18:22 PM on 3 March 2011Crux of a Core, Part 1b
Further to 13, Dansgaard et al (1993) describes the GRIP Summit Ice Core. It does not mention the cooling events in the Eemian that you referred to, although it does mention two others, one lasting 2 thousand and the other lasting 5 thousand years (page 220). It also compares the GRIP Summit core with temperature proxies from Nevada (Devil's Hole), data from the SPECMAP project (a global series of ocean sediment data), data from the Vostok Ice Core, and data from DSDP-609 (Between Labrador and Ireland, and South of Iceland) supplemented with sediment data of the coast of Ireland. Of these, only the North Atlantic sites (GISP, DSDP-609, and the sediments of Ireland) show the fluctuations, and only GISP shows fluctuations of such magnitude. These are definitely regional fluctuations in temperature, not global. -
Gilles at 17:17 PM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
Dana : Ok , so could you indicate me an "accurate" (in the sense of high confidence and low error bars) of climate sensitivity based on volcanic eruptions ? and precisely, the value obtained and the error bars ? (I assume you have good reasons to argue and you know a S±∆S value where ∆S<< S ?) Alexandre : read again. I said first that a possible reason not to reduce fossil fuels was the possibility that the future extraction would be after all low enough. You asked me for references. I showed you some. What's wrong with that ? I politely indicate you that some people think that official estimates are grossly exaggerated. It is not an EVIDENCE, it is a POSSIBILITY (just like a high CO2 sensitivity). But there is a HINT that they are right considering the case of oil. This is just an option to be considered. Muoncounter : "But this thread is not about models or modeling reliability; I referred you to that thread earlier. This thread is about climate sensitivity." Yes, and it shows that this quantity is not well determined by models. So again, I say that when the models rather strongly disagree with each others, their interval of results is not particularly significative. But you are free to believe in them - I'm free to be reluctant, and you won't convince me by telling ang telling you're right. You would convince me by a precise, reliable measurement of climate sensitivity (with a small error bar) -
Tom Curtis at 16:44 PM on 3 March 2011Crux of a Core, Part 1b
Norman @8, the claim you report is a summary of a claim on page 69 of this article (PDF). The data on which the claim is made is again Greenland icecores, so this is a variation in regional temperatures rather than global temperatures. Further, it is explicitly referenced to Dansgard et al (1993), "Evidence for instability of past climate from a 250-kyr ice-core record" (Published in Nature). This is, of course, another regional temperature fluctuation, not a global temperature fluctuation, and is probably associated with shutting down the thermo-haline circulation. -
Norman at 15:39 PM on 3 March 2011Crux of a Core, Part 1b
#9 and #10 Rob Honeycutt, I found the original document for the summary. It seems as if the authors are referring to Global temps. They use many sources for their claims as described in the full length article. Link to Document for Rob Honeycutt.Moderator Response: [DB] Fixed link html tag. -
muoncounter at 14:36 PM on 3 March 2011Crux of a Core, Part 1b
"between 135,000 and 110,000 years before present ... temperatures dropped from 2C warmer than they are today to 5C cooler in less than a few centuries" You really have to look carefully at time resolution for events that old. Do the original data justify hundred year resolution at >100k yr bp? "massive temp fluctuations" Even in GISP2 temp data, the big warmup from about 12.5kyr bp to 10.2kyr bp was 'only' ~17C in 2300 yrs, about 0.07C/decade. We're doing 2x that globally now; 5x that in the northern hemisphere. -
garythompson at 14:21 PM on 3 March 2011Crux of a Core, Part 1b
i've read the SkC original posting, the WUWT rebuttal and now the SkC rebuttal of the rebuttal and enjoyed all of them and learned some from each. thanks rob for your time in posting these articles. with regard to Dr. Hall changing the scales of the Vostok data to match the GISP2 data i didn't have an issue with this. he stated in the rebuttal that he did this and the reason for doing it. the purpose in doing this, as i understand it, was to show that both data sets had similar inflection points and showed common periods of warming and cooling. and the fact that greenland and antartica showed similar trends speaks to the theory that maybe both local temperature sets give a picture of the entire global temperature trends. Dr. Hall also notes that there are periods where the two set diverge in their trends as you stated in this post. and with regard to unprecedented temperatures of the 20th century - i'd say that antartica has seen warmer temperatures as the vostok data shows. but i agree with the posting here that you can't take that local temperature set and extrapolate that to the rest of the planet. but to my knowledge there isn't another proxy that dates back as far as these ice cores so until we get that for another part of the globe it must be feasible that the rest of the earth was warmer than the 20th century during these periods shown in the vostok data. if there are other proxies that show data contrary to this i'd appreciate a link so i can check it out. i'm trying not to get OT here but i'm trying to raise the point that since we are data limited for these long times in the past we can't rule something out that is supported by the only data we have.Moderator Response: [Daniel Bailey] Your linked image is behind a firewall, causing SkS users to input a password; as such the link was deleted. If you can find a version openly available, please re-link to it. Thanks! -
Sarah at 14:09 PM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
Another study of climate sensitivity: Hansen and Sato recently determined that climate sensitivity is about 3 °C for doubled CO2 based on paleoclimate records. They analyzed previous glacial-interglacial (and earlier) climate changes to understand what forcings were operating. Basically, they treated the Earth as a full scale model that was subject to various forcings including Milankovic cycles, and changes in ice cover, vegetation, and greenhouse gases. For example, between the last ice age 20 thousand years ago and now (actually, pre-industrial times), forcings increased by 6.5 W/m2 and the global temperature increased by about 5 °C. (see paper for uncertainty ranges). That is about 0.75 °C for an increased forcing of 1 Watt/m2. The authors emphasize that these results do not depend on any climate models; they are based on empirical observations. Thus they incorporate all real world feedbacks. "Paleoclimate Implications for Human - Made Climate Change", Jan 2011, James E. Hansen and Makiko Sato; preprint (maybe available from Hansen's NASA website).Moderator Response: [Daniel Bailey] Thanks, Sarah. The preprint is here. -
Rob Honeycutt at 14:05 PM on 3 March 2011Crux of a Core, Part 1b
Norman... Reading through this, my first comment is that, it's not a peer reviewed paper but a republished summary. I would want to read the original paper before coming to any major conclusions. Second, I would make note of the fact that the original paper came out in 1999 and, I would assume, based on older data. 1999 is about the time a lot of the ice core data was coming out. Third, again, no one assumes that CO2 is the only driver of temperature change. Large and rapid temperature changes are not proof that current warming is not anthropogenic. Remember Alley's analogy. Just because forest fires happened naturally in the past doesn't rule out arson as the cause of a current fire. -
Rob Honeycutt at 13:47 PM on 3 March 2011Crux of a Core, Part 1b
Norman... I haven't read the article you link to but I think the first question you have to ask yourself is, "Is that a local change in temperature?" Even Dr Alley says that many of the abrupt changes in the GISP2 record are related to a large variety of local events including snow drifts. So, you have to determine whether a temperature change is a climatic change or an event related change. -
Norman at 13:42 PM on 3 March 2011Crux of a Core, Part 1b
"Dr Hall's closing statement is "The 20th-century warming was hardly unprecedented, and doesn’t call for unusual explanations." This statement is completely unsupportable by the evidence Dr Hall is presenting. It would require that he perform a much more detailed study of a wide range of records to make such a statement. It is impossible to determine this from GISP2 alone" (from above article) I did find this article. I do not know how valid it is but the claims made in the arcticle would indicate our current warming is most insignificant of what has happened. I will link the article, maybe it is a bogus piece. This is always a good place to post such links as many intelligent minds will be able to determine it worth. Article with claims of much greater temp variations. For those not linking to the article. Here are some claims. "On two occasions between 135,000 and 110,000 years before present (BP), temperatures dropped from 2C warmer than they are today to 5C cooler in less than a few centuries. In one instance the temperature dropped 14C in a decade and returned to its former level 70 years later." Much greater temp change than anything today and without CO2 so if legite, what caused these massive temp fluctuations? -
scaddenp at 13:42 PM on 3 March 2011Australia's departing Chief Scientist on climate change
I am not expert on Australian resources but would have thought CSP not PV would have considerable resource in Australia. I agree though nuclear seems a pretty obvious way forward for Australia. -
Riduna at 13:02 PM on 3 March 2011No Illusions podcast interview (and elocution lessons from an 11 year old)
Unless I’ve just listened to an expurgated edition, I found it an informative interview, fluent replies and all defensible. Well done John Cook.Response: I'll pass on your comments to my 11 year old daughter but I think you'll find she'll agree to disagree :-) -
Tom Curtis at 12:40 PM on 3 March 2011Crux of a Core, Part 1 - addressing J Storrs Hall
Charlie A, your whole case comes down to not understanding the difference between attribution and analysis. Rob Honeycutt never says that J Storrs Hall did not correctly attribute the GISP2 ice core to the GISP2 site. He clearly indicates, however, that in his analysis, Hall treats the GISP2 records as though it were a global record. That Hall does treat the GISP2 record as though it were a global record is obvious in his comparisons between the variability in the GISP2 ice core and the recent rise in global temperatures. That comparison is explicit in Hall's article in which he refers to the "hockey stick", and in which he says temperatures continue "... up in the 20th century at least another half a degree." To start with, global temperatures rose by 0.8 degrees from the 1850's to the 2000's (the actual interval between the end point and modern times), or by 0.9 from the 1900's to the 2000's (the interval Hall thought to exist). So even if a comparison between local and global temperatures were valid, Hall has understated the temperatures increase by 40%. That sort of misinformation seems not to vex you, but as it is part of a critical point at issue, it shows a complete disregard for accuracy in Hall's analysis. More to the point however, as Hall is using a local record, he should have stated the additional increase in local terms. In other words, the state increase should have been 1.44 degrees (1850's to 2000's decadal average) or 3.7 degrees (1855 to 2010). In either case, the rise in Greenland temperatures in the 20th century would have had only two parallels in the chart, both (I believe) caused by events relating to the melting of the continental Ice Sheets following the preceding glacial. Now, either Hall new the difference between local temperatures and global temperatures or he didn't. If he did, then he knowingly understated the 20th century temperature rise by a factor of between 3 and 6 on a crucial point in his analysis; and is consequently a liar. If he did not, then Honeycutt's claim that "Hall presents GISP2 as if it were a global record ...". By arguing that Honeycutt is wrong about that, you implicitly argue that Hall is deliberately dishonest. There is no way around that logic. Honeycutt, not one to stoop to ad hominem, has taken the charitable interpretation that Hall is confused on the difference between local and global tempertaures. You apparently are not so charitable. However, whether Hall is dishonest or incompetent is a side issue. Your restricted focus on that issue alone shows that you are trying to distract readers from Honeycutt's devastating critique of Hall's argument. -
muoncounter at 12:34 PM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
"I do simply disagree", You're free to disagree, but that's one person's opinion (which is conspicuously unsubstantiated). You offer astrology's 'claim' to 'reproduce reality'? Hardly a meaningful comparison. Yes, models are predictive tools, so do you make one valid and useful point: See any of the threads here about models from as early as 1988 -- or even from 1981 -- and how well they have done. But this thread is not about models or modeling reliability; I referred you to that thread earlier. This thread is about climate sensitivity. -
Bern at 12:20 PM on 3 March 2011No Illusions podcast interview (and elocution lessons from an 11 year old)
Prompted by the podcast, I just looked up the Office of the Chief Scientist and what statements on climate science there were. I found this in the transcript of Professor Sackett's statements to the Senate Estimates committee hearing:"Scientists in every area of science are broadly telling us the same thing. And, when I say ‘scientists’, I would like to point out again—because I think it has been mentioned in these chambers before—that we are talking about all of science; we are talking about physics, we are talking about chemistry, we are talking about the science of the oceans. That is a very important message for people to hear. It is not a particular sort of scientist. It is not a scientist who works in government labs but not those who do not. It is not the scientists of one country only or a few countries only. It is scientists of all sorts in all countries, in all sorts of laboratories that are telling us the same thing. That is a message that I have great concern is not reaching the general populous at a level that engages them and enables them to ask the questions that they have in an environment where those discussions can take place without distractions of policy, without distractions of politics, if I may say. That is a great concern to me."
Well said, indeed! -
Bern at 12:14 PM on 3 March 2011No Illusions podcast interview (and elocution lessons from an 11 year old)
Have just listened to the podcast - not a bad discussion of the issues, thanks for that. I'd agree about the um's and ar's, in that it can be very difficult to avoid them. I would agree with your daughter's teacher, though - speak a little slower, consider your words a bit more, and it becomes much easier to avoid them. Slowing down your diction allows your brain to get ahead of what you're saying and have the next few words lined up - or so I've found, anyway, even if you have a few drawn out words or slight pauses in your sentence. (My boss is absolutely terrible at that, on phone conferences sometimes he'll say umm four or five times in a single sentence, and he speaks very quickly - which was not much fun when we were on a call to some guys in Brazil who have limited english!) -
Berényi Péter at 12:10 PM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
“the global mean equilibrium warming for doubling CO2...is likely to lie in the range 2°C to 4.5°C, with a most likely value of about 3°C. Equilibrium climate sensitivity is very likely larger than 1.5°C.” Equilibrium climate sensitivity alone is not too informative. What is the relaxation time? -
Ken Lambert at 11:34 AM on 3 March 2011Australia's departing Chief Scientist on climate change
michael sweet #21, scaddenp #22 Both you comments betray a lack of appreciation of the realities of scaling up 'renewable' sources of base load power to replace 83% of Australia's - let alone the developed world's energy needs. PV Solar is still 4-5 times the cost of coal - without storage devices - and would need huge capital investment. Wind is simply too dilute and far from population centres and suffers from the same increased cost of storage devices and transmission costs. Geothermal is a serious 24/7 contender - but still too small, experimental and far from loads. Nuclear is the only ready to go technology which can deliver base load. Australia has 40% of the world's uranium reserves but again our politicians live out a hyprocrisy that it is OK to sell to China and NNPT signatories and let them dispose of the waste but we are too pure to use it ourselves. Prof Sackett would not be smart if she did not know all these things - yet she makes these unrealistic exit statements in the knowledge that she would never have to deliver a renewable future. -
Daniel Bailey at 11:27 AM on 3 March 2011A Swift Kick in the Ice
Sorry, michael, for my confusion. You are 100% right. Just me being a dumb*** & not reading the actual news release from here but relying upon a 2nd-party news service (here). Probably just a typo, like 2350 becoming 2035... I plead laziness originating from our public school systems and too many teachers from the "flower power" generation. ;) Thanks for being gentle, The Yooper -
Alexandre at 11:19 AM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
Gilles, It's not the questions that annoy me (you don't ask many anyway). It's the row of unsubstantiated claims supported by the refusal to consider the available evidence that is more of a problem. There's nothing in those references that provide any evidence that most of the known reserves of fossil fuels (especially coal) will remain unexplored. Unfortunately. It's a great team of moderators, both in attitude and knowledge. I wish them all the patience to cope with this without wearing themselves out.Moderator Response: [DB] Thus far, sadly, I see the same modus operandi script being followed here as on RC. -
michael sweet at 10:59 AM on 3 March 2011A Swift Kick in the Ice
DB, I am not sure where you got your quote from. At the NSIDC website, they say the record was set in 2005, not 2007. They report the extent for the month of February to be record low, tied with 2005. (IJIS shows 2006 as the record low month. It is unusual for NSIDC and IJIS to differ). The current maximium is lower than the record low on IJIS, but NSIDC has not reported the maximium for the year yet. It is below, but very close to, the previous low maximum. A few cold days would put it over the previous record while a few warm days would set it under. At Cryosphere Today the Sea Ice Area (area is a little different from extent) is declining and the high would be a record low if there is not a major shift in the next few days. In any case, the ice is certainly not showing any signs of recovery this year. Your point is certainly correct: that's a really swift kick in the ice. -
dana1981 at 10:57 AM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
Giles, I'm using "accurate" to mean measurements with relatively high confidence and small error bars. For example, we know the temperature change over the past century to high accuracy, due to the instrumental temperature record. -
NewYorkJ at 10:47 AM on 3 March 2011Crux of a Core, Part 1b
Combining multiple locations and proxies in the Arctic and including the recent temperature average...
Arctic Warming Overtakes 2000 Years of Natural Cooling
At least for the last 2000 years and averaged over broader Arctic region, recent warming is very much unprecedented, and as we know, this conclusion can be extended to northern hemisphere average with fairly high confidence.
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Gilles at 10:47 AM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
"Models that tend to reproduce observations to date have a built-in check on how far their results can be 'from reality.' An ensemble of such models can then be used to describe 'likelihoods.'" I do simply disagree on this epistemological position. Astrology claims reproducing a fair part of reality, and you can do a statistics on astrological predictions. Ptolemaic models did reproduce a fair part of reality, and you could have imagined a statistics of how many epicycles are needed, and a "likelihood" of the number of epicycles of Mars. It would have been just bogus. Models are proved by accurate comparisons of predictions with data, not by statistical sets of approximate reproductions of reality. -
Gilles at 10:40 AM on 3 March 2011Climate Sensitivity: The Skeptic Endgame
Dana : "However, studies based on accurate measurements, such as responses to recent large volcanic eruptions (as discussed in the "climate sensitivity is low" rebuttal linked in the article)" maybe the problem arises from a different understanding of what is an "accurate measurement" ? I confess not being a native English speaker, could you elaborate what "accurate" means in your mind ? Dhogaza "Oil sands and natural gas fracking are putting large amounts of previously unavailable fossil fuel into the economy." Oh really ? what is your guess of how many toe these sources will produce in, say, 20 years ? " And "peak oil" says nothing about coal, which is available in copious quantities." Yes, peak oil says something : that the official estimates of resources are unreliable. -
bbickmore at 10:25 AM on 3 March 2011Roy Spencer’s Great Blunder, Part 2
WheelsOC @30, I think you're right that when Roy Spencer says "natural climate variablity" he really means "natural climate variability due to fluctuations in cloud cover". But that's not what he said, and some of the quotations above definitely imply that mainstream climatologists can't explain any climate change in the past before humans started burning lots of fossil fuels. So even if we try to give him a little leeway on his meaning, he still comes out looking disingenuous. -
Peter Offenhartz at 10:21 AM on 3 March 2011Roy Spencer’s Great Blunder, Part 2
@apsmith(19) Many thanks for the link to scienceofdoom.com. The article was clear and informative, and confirmed my own investigations(!). -
dana1981 at 10:17 AM on 3 March 2011Crux of a Core, Part 1b
Nice response Rob. I think it's pretty clear that Hall's original analysis and "rebuttal" were of extremely poor quality. It seems to be a rather convoluted misuse of GISP2 to argue that current warming isn't "unprecedented", therefore it's not anthropogenic. Even if the current warming isn't "unprecedented", that logic is like saying arsen is impossible because fires are known to start naturally. Only when investigators look carefully at all the evidence can they determine if a fire was started 'naturally' or by humans. Same thing with global warming. You have to look at the cause, not just the effect. -
dorlomin at 10:16 AM on 3 March 2011Crux of a Core, Part 1b
Greenland is an island partially surrounded by perennial sea ice and often exposed to the apparent vagrancies of sea and atmospheric currents. So it is quite possible to see changes in the Greenland record dramatically more variable than a global record. Without engaging with that subtantially I am at a loss as to what point Dr Hall was trying to raise. -
RickG at 09:42 AM on 3 March 2011Climate sensitivity is low
A curious digression on this topic - Dr. Roger Pielke Sr recently posted something on his blog, attempting to redefine the term Climate Sensitivity I wonder what's next, redefining the laws of physics to fit a specific outcome? -
KR at 09:30 AM on 3 March 2011Climate sensitivity is low
A curious digression on this topic - Dr. Roger Pielke Sr recently posted something on his blog, attempting to redefine the term Climate Sensitivity as: "Climate Sensitivity is the response of the statistics of weather (e.g. extreme events such as droughts, land falling hurricanes, etc), and other climate system components (e.g. alterations in the pH of the oceans, changes in the spatial distribution of malaria carrying mosquitos, etc) to a climate forcing (e.g. added CO2, land use change, solar output changes, etc). This more accurate definition of climate sensitivity is what should be discussed rather than the dubious use of a global annual average surface temperature anomaly for this purpose." Redefining a term used in all of climate science? I wonder why measuring the temperature response of the climate to a particular amount of radiative forcing wasn't working for him? This is a clear example of the Moving the Goalposts fallacy, often a sign that the original argument has been lost. -
damorbel at 09:27 AM on 3 March 20112nd law of thermodynamics contradicts greenhouse theory
Re #449 you wrote:- "Before that there was 'albedo', multi-layer insulation, 'sunlight can't make it out of the water', 'constant disequilibrium', 'elastic collision of photons', and the lovely bit of obfuscation, "All materials, even gases, have a refractive index >1, consequently no material substance can behave according to the definition of a black body"." This isn't a scientific argument of any sort, you do know that don't you? You cannot possibly imagine that material with a refractive index >1 can be a 'black body; it is in Kirchhoff's original definition; you have read Kirchhoff's work, haven't you? I think you may have trouble in discussing the matter you refer to as "elastic collision of photons". Photons do not collide there is no known collision process for photons, elastic or inelastic. Photons begin and end at electric charge, free or bound; that is the whole basis of electrophysics. I am beginning to wonder if you are aware of this. -
NewYorkJ at 07:57 AM on 3 March 2011Crux of a Core, Part 1b
Once someone uses the term "alarmist" and brings Al Gore into the discussion, they are pretty much exposing themselves. Hall apparently didn't read Alley's comment at DotEarth regarding point #1, since he doesn't address this: "First off, no single temperature record from anywhere can prove or disprove global warming, because the temperature is a local record, and one site is not the whole world. One of the lessons drawn from comparing Greenland to Antarctica and many other places is that some of the temperature changes (the ice-age cycling) are very widespread and shared among most records, but other of the temperature changes (sometimes called millennial, or abrupt, or Younger-Dryas-type) are antiphased between Greenland and the south, and still other temperature changes may be unrelated between different places (one anomalously cold year in Greenland does not tell you the temperature anomaly in Australia or Peru). After scientists have done the hard work of working out these relations, it is possible to use one ice-core record to represent broader regions IF you restrict consideration to the parts that are widely coherent, so it is O.K. to plot a smoothed version of an Antarctic temperature record against CO2 over long times and discuss the relation as if it is global, but a lot of background is required." Seems the details of this could be expanded on in another post. One interesting part of Hall's "rebuttal" is he changes the timescale by an order of magnitude from 10,000 years (his original post) to 100,000 years, so the goalposts shifted quite a bit. It's impossible to note any correlation from the graph over the last 10,000 years. Hall also claims Vostok shows the Younger Dryas event, but remove the artificial scaling done on his doctored graph, temperature change is magnified considerably. And did he shift the x axis as well?Moderator Response: [Daniel Bailey] "Seems the details of this could be expanded on in another post. " This is in the works. -
WheelsOC at 07:52 AM on 3 March 2011Roy Spencer’s Great Blunder, Part 2
nigelj @30: I think the key to understanding his meaning is to look at his recent "challenge to the climate research community".Studies that have suggested that an increase in the total output of the sun cannot be blamed, do not count…the sun is an external driver. I’m talking about natural, internal variability.
Indeed, his focus on "natural" variability excluding the sun keeps popping up in his writings, at least on the blog. More specifically I think he often means "natural variability" to refer to his causality-backwards idea that cloud cover drives mutli-decade climate trends.
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