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Comments 71101 to 71150:

71101. daisym at 17:24 PM on 2 November 2011
       Sorting out Settled Science from Remaining Uncertainties
       If natural forces are powerful enough to cool and offset warming attributed to manmade CO2, might they also be powerful enough to cause the warming attributed to man to seem greater than it really is?
71102. Rob Painting at 16:27 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       Shibui @ 44 - Aha, the false equivalence gambit.
71103. Bert from Eltham at 16:26 PM on 2 November 2011
       Fred Singer Denies Global Warming
       My mother who was a devout Christian always said that one day I would really understand when I got older and wiser that being an atheist scientist was wrong. She is dead now and I am much older and wiser and have not changed at all. The evidence still stands. We are dealing with people who are deluded. Nothing will change their mindset. It all reminds me of a case a neurophysiologist called Ramachandran had, whose patient had a delusion that he was dead. No logical argument could convince him that he was deluded. Yet he could see delusions in others! Sound familiar? Bert
71104. dhogaza at 15:50 PM on 2 November 2011
       Fred Singer Denies Global Warming
       rpauli: "Is Climate Change Real? Take a Look at the Science Before you Decide" The very notion that a headline like this is published is depressing. "Science says 'X" . Take a look at the science before you decide". Where else would you look? Genesis? (yes) Republican politicos who wave their hands and don't know their d**k from their rear end? (yes). etc. depressing ...
71105. oneiota at 15:07 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       Albatross@50 Indeed the scent of BS increased the closer I got to the source. Sphaerica: The ".html" dropped off the link all by itself... must be magic ;-)
71106. muoncounter at 15:02 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       Anyone looking for 'balance' will find more satisfaction in Scott Denning's video. "Its pointless to worry about decimal places. Its a big problem, and needs solutions. " Tell that to the crowd that thinks warming stopped for the last 20 minutes.
71107. Stevo at 14:56 PM on 2 November 2011
       Northern hemisphere warming rates: More than you may have heard
       Tom, Daniel, muon, Many thanks. Looks like you've given me plenty of reading for tonight.
71108. Tom Curtis at 14:47 PM on 2 November 2011
       Northern hemisphere warming rates: More than you may have heard
       Thankyou DB. The relevant papers are The Annual Cycle of the Energy Budget Part 1 and Part 2. Fasullo was the lead author of both, and both were published in 2008.
71109. Bob Lacatena at 14:34 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       44, Shibui, Okay. I looked at Ridley. It's mostly a lot of vacuous fluff, but I'm a little surprised that you didn't take the key points to heart, in trying to recognize pseudoscience (i.e. Watts, Nova, any number of cranks on the 2nd Law thread here, etc.) rather than presuming that his proclamations apply to the real science and scientists. I'm sure you clung to this statement, but in an upside-down, inside-out, black-is-white fashion:

       Lesson number 4: the heretic is sometimes right.

       but failed to take heed of this one

       Lesson no 5: keep a sharp eye out for confirmation bias in yourself and others.

       But when I got to lesson 6 I got angry, because I've seen that Feynman quote misapplied frequently since last year. In fact, I got so tired of seeing it misunderstood and misapplied that I wrote a post on it on my own too infrequently updated blog. The Feynman quote that he got wrong is here:

       "Science is the belief in the ignorance of the experts"

       His woefully incorrect interpretation of that quote is here:

       Lesson 6. Never rely on the consensus of experts about the future. Experts are worth listening to about the past, but not the future. Futurology is pseudoscience.

       This is wrong. It is an entirely inaccurate interpretation of what Feynman meant. Please take the time to read my commentary on The Ignorance of the Experts. And please... to compare this drivel to Milne's talk is a huge insult to Milne.
71110. muoncounter at 14:32 PM on 2 November 2011
       Northern hemisphere warming rates: More than you may have heard
       Stevo: One way to look at atmospheric CO2 distribution is with Carbontracker. The CO2 'weather' maps and movies are entertaining, if not informative.
71111. Tom Curtis at 14:30 PM on 2 November 2011
       Northern hemisphere warming rates: More than you may have heard
       Stevo @62, CO2 is a well mixed gas, so its concentrations are nearly identical in the Northern Hemisphere and Southern Hemisphere. Here for example are the CO2 concentrations at the South Pole and at Barrow Island in Alaska: In contrast to CO2 (and Methane), aerosols are not long lived in the atmosphere so are largely concentrated in the in the hemisphere of their origin, ie, primarily the NH. That is one of the major reasons for the difference in behaviour between NH and SH in response to global warming. The other major difference is that nearly all the worlds major land surfaces are concentrated in the NH. Because land warms much faster than the ocean, and because there is more land in the NH than the SH, the NH warms much faster on average than the SH. That pattern has been partly ameliorated by the high aerosol burden in the NH. As a result, during periods of rapid increase in aerosol load in the NH (most notably during the rapid industrialization that followed WW2 up until the clean air acts of the 1970's, warming in the NH was stopped or even slightly reversed. During periods of significant reduction in aerosol loads (the great depression) or stasis (1970's to 1990's due to clean air acts) the NH shows exceptionally rapid warming. This aerosol related pattern is not found in the SH: As for major methods of moving heat around, they are, as you conjecture, the the ocean currents, but also the major atmospheric circulations, particularly the Hadley, Ferrel and Polar Cells. I believe Fasullo and Trenberth have a paper discussing this issue, though I am uncertain who was the lead author and do not have a link to hand.
       Response:

       [DB] Trenberth's publication record is here.  Many PDF's available for download.

71112. Albatross at 14:19 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       Oneiota @49, Thank you for your thoughts on this. Wish I could give you your hour back. Seriously though, I try to consider such goings on a learning experience. I have learned an awful lot from considering the musings of self professed "skeptics" and chasing down what later turns out to be no more than spin, misinformation and opinion. These folks prey on those with preconceived notions (i.e., confirmation bias) and the gullible.
71113. Stevo at 13:57 PM on 2 November 2011
       Northern hemisphere warming rates: More than you may have heard
       I'm hoping this is an appropriate thread upon which to post this question. Could somebody please inform me or point me in the direction of which mechanisms spread warming around the planet, and how quickly this is likely to happen? e.g.How much warming is conveyed around the planet by ocean currents? Or how freely does CO2 spread around the entire planet? Since most fossil carbon is released in the northern hemisphere I can understand the north warming faster than the south, but how much lag should we expect before temperature rise rates in the south catch up with the north?
71114. oneiota at 13:45 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       Shibui @44 I too found Milne's talk interesting. On your recommendation and being a believer in finding balance and without a link to the Ridley talk in your post I searched and found via WWUT (as I'm becoming familiar with some of the landscape the acronyms are convenient) a transcript on Bishop-Hill I read and re-read and feel robbed of an hour of my life. I failed to find the balance and felt the need to visit Milne's talk once more for reassurance that I hadn't missed something. Frankly I resent it when a preacher has the arrogance to assume that I swallow an opinion without evidence for the argument....if Ridley gave permission to have the transcript published on Bishop-Hill and the asterix against the several claims made in his talk are meant to refer to footnotes and sources that aren't available to the reader then both Ridley and Bishop-Hill are merely preaching to the converted or to the gullible. Balance? Weigh this: How many lemons make an apple?
       Moderator Response: [Sph] Your link didn't work for me. Try this one for the Ridley transcript.
71115. Albatross at 13:22 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       Muoncounter, I actually did peruse Ridley's talk. Hence my reasoning that Ridley's talk does not represent "balance". But I sense that you are being sarcastic ;) It has gotten those in denial at WUWT (including Anthony of course) excited though, as expected. Fodder for the "skeptics" is what Ridley's talk is.
71116. muoncounter at 12:59 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       Albatross#45: "I am not sure how Ridley's talk is relevant here." Don't be so hasty. This Ridley talk starts off with a vital question: How do you know whether you are taking the rational or the irrational side of an argument, the scientific or the pseudoscientific position? Intrigued yet? Read on: There is a consensus that the earth is round and natural selection explains evolution, but there is also a consensus that ghosts and gods exist. Now anyone who can put the shape of the earth, natural selection, ghosts and gods into one sentence is clearly a savant. But then again, I didn't have a lot of trouble answering the original question, so maybe I'm not ready for this level of discourse. I'll stick with Milne.
71117. scaddenp at 12:51 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       This raises a problem commonly posed. Shibui is looking for balance - its a legal/political mode of truth determination. "Prosecution and defense" present their case and it is left to individual to determine what is true. Add into this is common relativist idea that both can be forms of truth. Not so with science. Nature is judge. Debate is settled by collection of data. However, for Shibui, it seems there is the problem of who to believe, who to trust? If you cant do the science yourself, (most of us, even scientists when outside field), then how to judge? For those of us working in science, it seems obvious to go with consensus in published, peer-reviewed research by the experts in the appropriate field. Do you prefer to go with the journalist just because you prefer that opinion?
71118. Albatross at 12:31 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       Shibui @44, The implication being that the "truth" is in the middle somewhere. So what you are asking for is "false balance". I see that you follow Bishop Hill or WUWT or both. I sense your bias already. Dr. Milne has done some research in the field of climate science and the impacts of climate change on plants, quite unlike Dr. Riley who is foremost a journalist. Milne RI (2006). Northern hemisphere plant disjunctions: a window on Tertiary land bridges and climate change? Annals of Botany 98: 465-472 Also, I am not sure how Ridley's talk is relevant here. In addition to calling for false balance, you seem to be floating a red herring, as well as ignoring Ian's comments @ 43. You do not just ignore inconvenient facts and then move on Shibui. You can try, but I won't let you :)
71119. muoncounter at 12:18 PM on 2 November 2011
       Fred Singer Denies Global Warming
       Steve L#10: "I think it 'works' like this:" It's important to lay this 'logical' chain out in the order you did. Item 1 is among the foundational principles of the denialists. Normal logic would say that if a foundational principle (a given, if you will) is wrong, the whole structure crumbles like a house of cards. Switching to rhetorical mode: Has anyone asked what evidence there is for item 1? Can anyone in denial do anything else than pre-suppose that item 1 is true? I think not. End rhetorical. The comments on JCurry's blog after tamino's questions popped up are a case in point. He asked a scientist, who had taken a position without having to show any evidence in support, to show that evidence. The 'denizens' thought that was ill-mannered, rude and a personal attack. You dare you ask our favorite scientist a straightforward question? Not on our watch! And we're supposed to be looking for common ground with these folks?
71120. Shibui at 12:07 PM on 2 November 2011
       Richard Milne separates skepticism from denial
       Dr. Milne was very interesting. For balance, can I recommend Matt Ridley's recent Angus Millar lecture at the RSA in Edinburgh.
71121. Steve L at 11:12 AM on 2 November 2011
       Fred Singer Denies Global Warming
       Riccardo, you don't see their logic. I think it 'works' like this: 1. Scientists who believe in anthropogenic global warming (or whatever) are greedy liars or are incompetent. 2. When they find warming, they either fudged the data or performed the analysis wrongly or ignored important contradictory stuff. 3. If someone who doesn't believe in AGW finds cooling or no warming, he or she has done it right, with all the proper data. 4. If someone who doesn't believe in AGW finds warming, he or she has probably done it right (because people who don't believe in AGW are more competent and trustworthy), but warming doesn't mean it's anthropogenic. 5. If someone who doesn't believe in AGW finds the same amount of warming as someone who does believe in AGW, however, there's trouble -- this would likely mean that the scheming or incompetent true believer didn't do anything wrong, or the non-believer made the same errors. Therefore, #5 can't be correct, because the only thing that makes sense in this worldview is that those who disbelieve in AGW are better than those who think it's a real problem. Any common ground is an affront to the natural order.
71122. Tom Curtis at 10:33 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       Two additional points that are worth noting: 1) The BEST data clearly shows a continuing global warming trend since 1998. In fact, Judith Curry, as co-author has commented on just that fact, saying:

       "Though it is sometimes argued that global warming has abated since the 1998 El Nino event (e.g. Easterling and Wehner 2009, Meehl et al. 2011), we find no evidence of this in the GHCN land data. Applying our analysis over the interval 1998 to 2010, we find the land temperature trend to be 2.84 ± 0.73 C / century, consistent with prior decades."

       (Rhode et al, 2011, h/t to Tim Lambert) As the confidence interval on the trend indicates, they even find the trend to be statistically significant, with a minimum value for the confidence range of 2.11 degrees C per century. Based on Tamino's analysis, and critique of the use of white noise models for temperature, that confidence is overstated. Tamino shows a minimum trend inside the confidence interval of around -0.4 degrees C per Century (on the full BEST data) for the trend since 1998. Never-the-less, Judith Curry's official position is that the trend since 1998 is large, and statistically significant. If she now disagrees with that, as she apparently does, she has no honourable course but to either persuade her fellow authors to ammend that claim, or to withdraw as an author of the paper. Observant readers will note that the quoted trend is for GHCN stations only. However, the paper in question shows the difference between NOAA (GHCN) and BEST values in graph 8b. In 1998 NOAA shows a higher value than does BEST, but by 2010 it shows a lower value. That (consistenly) declining trend over the interval shows that the full BEST trend will be larger than that quoted above, not smaller. As the full BEST temperature series uses more data, it will also have a more tightly constrained confidence interval. Given that Muller is also a co-author of this paper, his claimed vacillation on statistical significance on just that interval is even more bizzare. It means he is either unaware of the contents of the paper of which he is co-author, or he has (quite reasonable) doubts about the statistical model used in calculating the confidence interval. If the later, however, it is incumbent on him to ensure those doubts are expressed in the paper. 2) Although I criticized BEST for including the two Antarctica only values for April and May of 2010 in their analysis, on reflection it is not clear that they have done so. Certainly none of their graphs show the precipitous decline in the final values (though none of their graphs are unsmoothed monthly graphs). They may have, in fact, done the correct thing in including the data in record (the data has been collected), but excluding it from their analysis. If that is what they have done, it raises two issues. A reason for excluding the data should have been given in their papers. Indeed, if they have not excluded the data an even better reason for not doing so should also appear in their papers. What should not occur is either inclusion of dodgy data, or exclusion of any data without comment. Again, if they have excluded the data, Judith Curry should have recognized the inclusion of dodgy data in the graph she was asked to comment on, and made a point about it. She certainly should have indicated the dodgy nature of the data when she made her clarifying blog post. Her failure to do so shows either that she is quite happy to use data she knows to be misleading, and which biases the data in favour of the case she is arguing; or that she was not aware of data issues in a paper of which she is co-author. Neither reflects well on her.
71123. Composer99 at 10:31 AM on 2 November 2011
       Fred Singer Denies Global Warming
       

       I'd expect a reputable scientist to think twice. [Emphasis mine.]

       Ah, see, there's your problem. :)
71124. adelady at 10:26 AM on 2 November 2011
       Fred Singer Denies Global Warming
       John, you and your mother should get every allowance that anyone could make. Not so Fred Singer. He's been making wildly unjustified claims about a whole variety of topics for decades now. If there's been any change in his behaviour or cognition, it's not apparent to me.
71125. DrYew at 10:16 AM on 2 November 2011
       Fred Singer Denies Global Warming
       On the Global Warming Policy Foundation website, David Whitehouse headlined his initial blog on BEST thus: 'Sceptical Berkeley Scientists Say, “Human Component Of Global Warming May Be Somewhat Overestimated”', making the same mistake as the one Singer did in his Nature post. I wrote to Whitehouse pointing out that this was pure spin. His response was that the headline wasn't taken taken out of context because the section in which phrase occurs is "poorly argued": ie, he knew better than the authors what they meant. Is this type of self-contradictory, Janus behaviour common amongst the sceptic, sorry "skeptic" community? :-)
71126. John Russell at 10:12 AM on 2 November 2011
       Fred Singer Denies Global Warming
       I am very aware that what I'm about to say could be considered ad hominem and stands a good chance of being deleted, but it's perhaps worth saying. My mother, who is a year younger than Fred Singer, has been living in a home for the elderly for several years now. Although she was a clever woman -- a head teacher -- she gradually lost her ability to apply logic and eventually became somewhat demented. I remember only a year ago she looked up at the moon on a clear evening and told me, with absolute conviction, that she'd been there. I feel very sorry for people who were once so capable as they start to lose touch with reality. It's very sad and perhaps we should make allowances.
71127. Tom Curtis at 09:25 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       Dikran Marsupial @71, the heavy computational load of Bayesian methods was why frequentist methods came to dominate science before the invention of computers. Why they continue to dominate science is a more open question.
71128. dana1981 at 08:56 AM on 2 November 2011
       Fred Singer Denies Global Warming
       Really it's stunning that anybody would seriously try to deny that the planet has warmed since 1940. That's either extreme ignorance or extreme denial, and in Singer's case, it's clearly the latter. He knows better. I just couldn't believe he actually said this in a comment to Nature, one of the most prominent peer-reviewed journals in the world. If Singer had any credibility left before this incident, it's gone. This is just disgraceful. It's just impossible to take anything he says seriously after this.
71129. r.pauli at 08:55 AM on 2 November 2011
       Fred Singer Denies Global Warming
       Just read a great article in OilPrice.com "Is Climate Change Real? Take a Look at the Science Before you Decide" http://oilprice.com/Environment/Global-Warming/Is-Climate-Change-Real-Take-a-Look-at-the-Science-Before-you-Decide.html
71130. dana1981 at 08:40 AM on 2 November 2011
       Sorting out Settled Science from Remaining Uncertainties
       Daisy, I suggest you click the links in the article, which show that these examples are indeed facts/settled science. Your claims to the contrary are simply wrong, and based on a misunderstanding or lack of understanding of the scientific evidence discussed therein.
71131. Bob Lacatena at 08:12 AM on 2 November 2011
       Sorting out Settled Science from Remaining Uncertainties
       15, daisym, The ocean cannot be contributing to the buildup of CO₂ in the atmosphere because it is, in fact, itself absorbing a large amount of the anthropogenic emissions (i.e the amount of CO₂ in the ocean is measurably increasing, not decreasing). Visit here and here for more information (to start). As far as your claims of assumptions... they are false. You are yourself making a great number of (false) assumptions about the science without understanding it, but I can't direct you to just one or two links to settle that matter, because the gap is too large. You need to study more, and assume less. You will find that the answers to most or all of your own assumptions and misconceptions can be found on this site if you take the time to look, read and understand. The question of who believes that the science is "settled" (itself a strawman argument) not a political question, and is not in doubt. That some would like to make it seem to be a political question is true. That a very, very small but vocal number (like Spencer and Curry) can fool people such as yourself is true. But if you were a skeptical person, you would learn more, understand more, and see through the illusions they present.
71132. WheelsOC at 08:08 AM on 2 November 2011
       Fred Singer Denies Global Warming
       Singer's comment at Nature includes a lot of content from his letter to the Washington Post dated the previous day (which I can only find as originally posted at WUWT). I instantly recognized the bizarre claims about atmospheric and proxy trends that he seems to have totally invented. Of course none of it is backed by references to the literature, so it's impossible to verify against any particular data. My favorite part is where he cites the BEST line that 70% of US stations are poorly cited, ignoring that in the very same paper they found that these siting issues make no real difference.
71133. JMurphy at 08:05 AM on 2 November 2011
       Sorting out Settled Science from Remaining Uncertainties
       daisym : "Too many scientists have yet to embrace AGW to consider the science to be settled." Very subjective statement there : care to back it up with a number for that "too many" assertion ?
71134. KR at 07:56 AM on 2 November 2011
       Sorting out Settled Science from Remaining Uncertainties
       daisym - "Only one of the three examples for settled science (presented in the first paragraph of the article) is valid fact. The other two examples are conclusions, not facts." Sadly, daisym, all three statements are settled facts. I strongly suggest you follow the links embedded in those three statements in the OP, and look at the copious evidence that supports them. Unless you can point out some references (preferably peer-reviewed) that indicate CO2 rise is not due to our emissions? Or that CO2 does not increase the greenhouse effect, or that the 4% water vapor rise over the last 30-35 years is not acting as a feedback? Otherwise, you are simply making unsupportable denialist claims.
71135. AussieinUSA at 07:37 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       Note: AGW - Anti Global Warming
71136. AussieinUSA at 07:36 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       @ Comment 47 - Kudos on a wonderful graph showing how AGW people see the cooling trends, as compared to the actual warming trend.
71137. daisym at 07:36 AM on 2 November 2011
       Sorting out Settled Science from Remaining Uncertainties
       Only one of the three examples for settled science (presented in the first paragraph of the article) is valid fact. The other two examples are conclusions, not facts. It IS a fact that the Earth’s surface has warmed. To claim as fact that "...the increase in atmospheric CO2 levels is due to human emissions..." assumes that the 90% (give or take) of Earth's CO2 which resides in the oceans isn't also a significant contributing source of atmospheric CO2. To claim as fact that "...the increase in CO2 is responsible for a substantial fraction of that warming" assumes that the feedback role of water vapor and clouds is factual as well. This isn't the case at all. It’s assumed that water vapor and clouds must amplify the raw CO2 warming to produce the harmful warming attributed to manmade CO2. Without this assumption, there’s no case against manmade CO2. Explaining the slowed surface warming is especially problematic. If natural forces are powerful enough to cool and offset warming attributed to manmade CO2, might they also be powerful enough to cause the warming attributed to man to seem greater than it really is? Who really believes that the science is settled? This is a political question. Too many scientists have yet to embrace AGW to consider the science to be settled.
       Response:

       [DB] "Too many scientists have yet to embrace AGW to consider the science to be settled."

       As in more than 2-3?  You must cite specifics with links to sources to back up your assertions.

71138. Albatross at 07:33 AM on 2 November 2011
       Fred Singer Denies Global Warming
       Thanks Riccardo. Yes, the number of logical fallacies that those who deny the reality of AGW have to make is quite impressive. "Skeptics" and those who deny AGW are really not sure what to do about the BEST results. At the same time they are accusing the BEST team of fraud, they are also claiming that they never doubted it was warming, while also claiming that the BEST data show that "The human component of global warming may be somewhat overestimated", while also bending over backwards cherry picking to try and claim that the BEST data show it is in fact now cooling! They have very vivid imaginations. When the results first came out their immediate reaction was "We never denied that global temperatures are rising!", in about a week that cry has quite miraculously morphed into "The BEST data show that global warming has stopped!". What they are doing beggars belief. Singer's error riddled post was of course given front page status at WUWT, a blog that Dr. Roger Pielke Senior assures is "devoted to the highest level of scientific robustness". Instead of being 'skeptical' about the claims made by Singer (which probably originated from a lobby group which denies AGW and which has a history of playing loose with the truth), Mr. Watts and Dr. Singer were quite happy to propagate the falsehoods and add a few of their own for good measure. In February 2011 Singer said this at WUWT: "I applaud and support what is being done by the Project — a very difficult but important undertaking. I personally have little faith in the quality of the surface data, having been exposed to the revealing work by Anthony Watts and others. However, I have an open mind on the issue and look forward to seeing the results of the Project in their forthcoming publications." Like Watts, he has too reneged on earlier assertions about being open minded about the BEST findings.
71139. Bob Loblaw at 07:26 AM on 2 November 2011
       Fred Singer Denies Global Warming
       Minor nit: I think you've accidentally cut and pasted a closing sentence from some other topic. I don't think the phrase "I'd expect a reputable scientist to think twice" belongs in an essay on Fred Singer.
71140. John Russell at 05:49 AM on 2 November 2011
       Sorting out Settled Science from Remaining Uncertainties
       @actually thoughtful writes: "I fear a return of solar activity, as the deniers will then say it is the sun now, it was the sun, and it will always be the sun." Well in many ways they're right -- best first to agree with them that the energy for the warming comes from the sun -- always has, always will -- and therefore the rate of warming will vary according to the sun's output. Then when they're nodding in agreement go on to say that the real issue is that we're increasing the thickness of the duvet on the bed; so as the central heating provided by the sun turns up, under the covers we start to overheat. In other words the concentration of CO2 in the atmosphere is purely passive -- just like a duvet on the bed -- but as it thickens, the heat it traps raises the temperature to uncomfortable levels. This explanation usually works.
71141. Tristan at 05:42 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       Wonderful, thanks a lot. :) From what I gathered frequentist and bayesian stats give similar results except in corner cases (limited data and very low success/fail rates). I know one of my friends used bayesian stats when he was working at LIGO trying to find those elusive GWs.
71142. Dikran Marsupial at 05:24 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       Tristan E.T. Jaynes' book is very good, it is hard going, but worth the effort. The real problem with Bayesian methods is that while they are conceptually easier to understand that frequentist methods, and harder to misinterpret, the computation is generally much more difficult, which I suspect is the reason they are not used more widely. I myself am a Bayesian by inclination, but I end up using frequentist methods a lot of the time for that very reason.
71143. monkeyorchid at 05:21 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       Shocked by Prof. Curry. Until today I had her down as a genuine skeptic, but if so then her Daily Mail interview indicates that she is hideously naive with regard to the press. If she's a genuine skeptic, how can she be so daft as to give ammunition to a newspaper that will turn her into a mouthpiece for the denial industry, whether she likes it or not? Can she not understand that the damage she's done by talking to the Mail far outstrips any flaws in the BEST analysis, even if she's completely right about all of her gripes? Or maybe she's been seduced by the dark side. Wonder if David Bellamy has a spare Darth Vader helmet he can lend her? Or perhaps she feels insulted by something Muller has done, and is getting her own back, not caring about the effects on public opinion (except against him). There is no way of looking at this that casts her in anything other than a very poor light.
71144. Dikran Marsupial at 05:18 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       les thanks for the links. The best summary of the key problem I have seen is that "we want evidence of a significant difference, not significant evidence that a difference exists". It is very rare for two samples to actually have the same population parameters (e.g. for a drug to have precisely no effect - if that were true it wouldn't have gone as far as a clinical trial in the first place), so if you have a large enough population, you can always reject the null hypothesis even if the actual difference is way too small to have any real meaining. Testing for normality is the classic example of this. Random variables are only truly normally distributed in some assympotitic limit, which never actually applies in the real world. So when you are testing for normality you usually know that the null hypothesis is false from the outset, you are just checking to see that your sample is small enough that it could be confused for a normally distributed sample, and hence assuming it is normal to make the maths easier probably won't cause a problem!
71145. Tristan at 05:11 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       Thanks for the link DM. [OT]You have no idea how frustrating it was to go through a stats major (The MA was no different either) at university learning nothing but frequentist stats even though my lecturers acknowledged that significance testing was outdated and that bayesian analysis was a better approach. There was nothing in our textbooks (~2005) more recent than procedures from the 1950s. I've been meaning to teach myself bayesian stats for a while now. Is there a text you'd recommend?[/OT]
71146. les at 05:04 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       65 - Dikran Yes, thanks. I think it helps to emphasis that she is not testing for a change of rate / rate staying the same (null hypothesis). But that the specific time period shows no warming... then here statement from Tamino post "“There is no scientific basis for saying that warming hasn’t stopped” is talking about whether things changed .... so she has clearly applied the wrong test for the statement. as an aside... talking about the strangeness of hypothesis testing... this The Cult of Statistical Significance and thisare quite fun.
71147. Dikran Marsupial at 04:50 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       Tristan Have you read E.T. Jayne's paper on confidence intervals. It is well worth a read, I especially liked the example of a correctly constructed confidence interval where you caoul be 100% certain from the sample of data that the true value of the statistic could not possibly lie within the confidence interval. While it is a bit polemic in style I found it very helpful in understanding what confidence intervals tell you and what they don't.
71148. Dikran Marsupial at 04:46 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       les Essentially the important issue is that frequentists hypothesis tests are not symmetrical; if we exchange the null hypothesis with the alternative hyopthesis, we do not necessarily get the opposite answer. Essentially the test assumes that the null hypothesis is true and it is up to you to prove that it isn't. This gives a correctly cautious approach to assessing the evidence for our hypothesis. Prof. curry though is arguing FOR the null hypothesis used in the test for the presence of a warming trend. So she is assuming that she is right and it is up to the data to prove he wrong, which is very different and frankly dangerous approach to statistical analysis. The correct thing to do would be for Prof. Curry to re-frame the argument, so that warming at the long term rate were the null hypothesis and that the alternate hypotheisi were that there had been a change in the trend. She would then have to demonstrate that the null hypothesis (no change in the warming rate) were unlikely to be true. In this case, the time period is so short that the null hypothesis is unlikely to be rejected in either test, which is because there is too little data to be sure either way. However, Prof. Curry is the one arguing that there has been a change in something, so Occam's razor (the simplest explanation is probably correct) suggests that we should have a preference for "no change" over "change" to some degree. If this sounds confusing, don't be worried by that, the more I look into frequentist hypothesis testing, the more I wonder how we arrived at the recipe we currently use in science!
71149. Steve Bloom at 04:45 AM on 2 November 2011
       Not so Permanent Permafrost
       Re #s 7/11: AIUI, high northern latitude Eemian warming resulted fairly directly from Milankovitch forcing. That's not the case now, and in particular warmth carried to the Arctic by warming currents (originating in e.g. the Agulhas) is a big factor. Also, the current temperature rise is much faster than during the Eemian, which seems likely to result in somewhat different melting effects (and much greater forcing per unit time). But the main lesson from the Eemian seems to be that a relatively mild push (compared to what we're doing) resulted in a lot of melt, although mostly of land-based permafrost rather than the much nastier stuff that lurks off the coast. A point I wanted to add that may have been mentioned in one of the prior related articles here but IMO doesn't get mentioned enough, is the geologic uniqueness of the yedoma and the shallow ESS permafrost/clathrate deposits. Their presence requires, variously, a shallow Arctic Ocean, a deep freeze (noting that this is only the third such of the Phanerozoic), an extensive Arctic coastal area that doesn't glaciate, and finally major rivers that dump large amounts of carbon-rich sediment into the shallow coastal zone. I haven't seen a scientist address this exact point, but the uniqueness of this combination of factors (leading to immense amounts of CO2 and methane mobilizable by us) seems clear enough. It's a whole nest o' Krakens, and we're stepping in it.
71150. Tristan at 04:35 AM on 2 November 2011
       Baked Curry: The BEST Way to Hide the Incline
       "There is no scientific basis for saying that warming hasn’t stopped [since 1998]" Which is wrong, but what she meant to say was: "One cannot reject the null hypothesis of 'the warming has stopped since 1998' using the BEST data" She's right but it's pretty meaningless.

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