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Comments 64851 to 64900:

  1. CO2 lags temperature
    jzk @333, the short answer is that after the passing of the peak Milankovitch NH Summer warming, the Earth cools very slowly over several thousand years. Because cooler water absorbs more CO2 than warm water, that cooling gradually reduces the CO2 level in the atmosphere. Studies have shown that a Milankovitch Minimum NH summer warming will initiate a new glacial only if CO2 levels are at around 240 ppmv (+/- 40 ppmv). The large range is due to the fact that there are a range of studies giving partly overlaping results in that interval, and also because the level of CO2 that will stop the initiation of a glaciation depends critically on the strength of the Milankovitch Cycle. Historically, at least on glacial commenced when CO2 levels where at around 280 ppmv, but most initiate with levels around 240 ppmv, and Berger and Loutre show that even in a weak cycle, glaciation will initiate with CO2 levels around 210 ppmv.
  2. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    I like Manns work and the thousands like him that contribute to our knowledge about AGW. But I don't have the attention span these days to read peoples 'life' stories. I did start reading it (like I started reading Hansens book) but got bored. I wish these scientists would spend time to write popular science books or work on TV documentaries that get the science across to millions of people, instead of this sort of thing. That would be far more productive than these types of books.
  3. Medieval Warm Period was warmer
    Tom @73, I have no problem drawing that conclusion from the Mann data, and of course I have noticed that. That is the kind of presentation that SkS should have. But picking a decade of our recent warmest data (+- 3 years) and comparing it to 300 years of previous data just so that one chart will be full of white and the other red does nothing other than to mislead people that don't actually look to see what is behind the chart. I use the word "mislead" as a description of the effect of the comparison, not the intent. I have no idea what the intent was. If the data are on your side of the initial premise anyway, why not just present it in the most fair way possible?
  4. Dikran Marsupial at 23:58 PM on 9 February 2012
    CO2 lags temperature
    jzk The change in CO2 between glacial and interglacial conditions is only from 190 to 270 ppm, an as the fadiative forcing from CO2 only increases logarithmically it isn't necessarily "very strong" compared to the change in solar forcing due to Milankovic cycles. You would need to compute the numnbers to know whether your argument was valid, and I strongly suspect that the scientists did that before publishing their finings. Also the feedback from CO2 is self limiting in the sense that IIRC the outgassing of CO2 due to heating of the oceans is linear, so in the absence of external forcings it would rapidly (on geological timescales) reach a new equilibrium. Thus by the time Milankovic cyle went into a cooling phase CO2 would no longer be on the way up.
  5. CO2 lags temperature
    I am very interested in understanding how the Milankovich cycle at the top of the cycle reverses warming when the influence of CO2 is so strong and continuing to experience positive feedback (although perhaps diminishing). I understand that "Northern ice sheets melt less during summer and gradually grow over thousands of years. This increases the Earth's albedo which amplifies the cooling, spreading the ice sheets farther." However, before that can happen, the cooling effect to prevent the melt via the top end Milankovitch factors must overcome the very powerful warming effect that the high level of CO2 has. At this point, of course, CO2 is still rising and ought to be more powerful than any other time during the cycle. The Imbrie, et all papers don't deal with this that I can see. I realize that this issue isn't novel having been discussed on this forum before, but what peer reviewed authority engages this issue? Thanks!!!
  6. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Pirate and Dale, Your Wattsian views of the issue as a debate with sides, recruitment, demarcation lines, and most importantly "belief" all point to a perspective that this is all about personal choice. On the one hand, I'd tell either of you that your time would be much better spent reading something else that teaches you about the actual science. On the other had, given your rather chauvinistic-militaristic view of the issues, perhaps what you need is a better insight into the perspective of someone other than yourselves (like that of a scientist who is doing his job, coming up with data and analyses that other people don't like, and then being hounded and vilified for it). You two are exactly the sort of people who should read the book, but with an open mind and an eye towards learning something about how your fellow skeptics behave and the use of "tactics" as an approach to a field of science, rather than participation in the science itself.
  7. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    31, Bernard J. That's not at all a bad idea, and one that would be easily enforced. At a minimum, there should be a big icon next to a commenter's name showing who has or has not bought the book from Amazon. Comments should also be sorted in that order (people who bought it first, people who claim/pretend to have bought it second), and summarized that way ("Average rating for the people who bought the book from Amazon, 4.89, Average rating for all others, 1.32").
  8. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    What is particularly interesting, in a behavioral way, is the swarming of the Amazon site. I'm still reading Mann's book, but the goings-on with all those negative reviews from people who must somehow be able to read dozens of pages a second (!!!) provide an absolutely classic example of the politics of the climate debate. Mann writes an account of it and a whole bunch of helpful dudes then come along to provide of working demonstration of what he describes!
  9. Dikran Marsupial at 22:29 PM on 9 February 2012
    Still Going Down the Up Escalator
    RobertS (various posts) "Slope in a linear regression of either temperatures or GCM output, however, is still an unobservable parameter - it's not a measurable, identifiable feature of the data itself, but of your particular model - and cannot be verified" This is not true, as others have pointed out there the data has a unique linear least-squares fit, just as the difference between the temperature at the start point and end point is uniquely defined by the data (as I pointed out on Dr Brigg's blog). You can view linear regression as being a generative model of the data, however it also has a perfectly reasonable interpretation as a descriptive statistic. "but I believe Briggs overall point is that the frequentist interpretation of confidence intervals is not intuitive, which begets confusion." This is true, conidence intervals are counter-intuitive, however if that is Brigg's overall point he is making it rather indirectly, to say the least! "And that confidence/credible intervals of observables is preferable to confidence intervals of model parameters." This is non-sense, which is preferable depends on the purpose of the analysis. "I don't have a problem with a global mean surface temperature. The issue comes with how uncertainty in this value is calculated and viewed, and how a change in GMST is determined." Are your concerns answered then, by my analysis which shows that using Bayesian methods, the uncertainty in the estimates of GSMST have almost no effect on either the expected regression or the credible interval? You might want to ask yourself why Briggs hasn't already performed this analysis before making a fuss about it on his blog. BTW, not all statistics should be "predictive", they should be chosen to suit the purpose of the analysis. If you are aiming to predict something, then obviously predictive statistics are likely to be most appropriate. If the purpose is to describe the data, then descriptive statistics are appropriate, if you are exploring the data, then exploratory statistics. Ideally a statistician should have all of these tools in his/her toolbox and be able to chose the appropriate tool for the job at hand.
  10. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    I for one am dissapointed the spoilers are getting removed. Perhaps someone can get in touch with Mann and see if he can get Amazon to keep them up. They are pretty much evidence of the books argument.
  11. Dikran Marsupial at 22:09 PM on 9 February 2012
    Still Going Down the Up Escalator
    Steve L The Bayesian analysis doesn't take autocorellation into acount (unlike Tamino I am no expert in time-series analysis - yet ;o). However the main aim was to determine whether the effect of the uncertainty of the estimates of GMST had much of an effect on the width of the credible interval. It doesn't which suggests that Dr Briggs is making a bit of a mountain out of a molehill (if not a worm cast), in my opinion. BTW, if you are interested in Bayesian statistics then a good place to start is Jim Alberts book "Bayesian Computation with R", which as a package for the R programming environment called "LearnBayes" that implements Bayesian linear regression (which I used to generate the plots).
  12. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    I've just checked and can report that Amazon appears to have removed the short, 1-star, deliberate 'spoilers'. Actually the reviews now left seem to illustrate well the polarity of the discussion and, if anything, will encourage the casual viewer to read the book. So shall we call this 'bookgate'?
  13. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Other than Craig Loehle, none of those opposed to Mann have done their own reconstructions. This one of the salient points, they dont have a credible alternative to offer.
  14. Global Sea Level Rise: Pothole To Speed Bump?
    Skywatcher/KR Understood ... collaps means exactly that. Nothing gently timeconsumig about it. (I got waylaid by language, like: economic collapse) Thank you for clearinng the head. It isn't a story easily told to Monckton enthousiasts though (there are still a few left).
  15. Volcanic Influence on the Little Ice Age
    @Klaus 20 - Scaddenp quotes the best reconstruction. Add to that a Swedish study that highlights the disjoint between past northern and southern hemisphere trends. http://www.physorg.com/news/2011-10-simultaneous-northern-southern-hemispheres-result.html It's noteworthy for the current warming that the effect is ubiquitous. That's very different from the reconstructions that show both regional and hemisphere differences driven by natural variations.
  16. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    The denialist carpet bombing shows a serious flaw in Amaon's comment system. It is being hijacked for political purposes - something about which the Amazon management should be excedingly concerned. Frankly, reviews for topical material books such as this one is should only be accepted from people who have purchased it from Amazon. Similarly, comments should only be accepted from folk who have a minimum purchase history with Amazon. It's not only in Amazon's interests as an ethical trader, but as a successful one, that they weed out politically-motivated nonsense.
  17. Still Going Down the Up Escalator
    RobertS, the data of the temperature series is a set of pairs of numbers. The linear regression of such a set has a unique solution. Therefore it is a property of that set of numbers. So, to answer the question, it is a property of the data set, not of our mathematical manipulation. We could employ the same form of verbal tricks you do in making your case with regard to measurements. Consider a simple mercury thermometer placed in a pot of water. The length of the mercury column in the evacuated tube depends critically on the diameter of that tube. Does that make the temperature a property of the evacuated tube, of the the manipulation of glass in creating the tube? By your logic we must conclude it is a property of the glass blowers manipulation. Perhaps that is to simple for you. Suppose instead of a mercury thermometer we measure temperature with an IR thermometer. The IR thermometer records the intensity of IR radiation across a range of frequencies. Using the laws of black body radiation, a computer chip then calculates the temperature of the body emitting the radiation. So, is the temperature a property of the pot of water, or the mathematical manipulation that derived the temperature from the IR radiation. For consistency, you need to say the later. But then you are committed to the claim that Planck's law has a temperature of x degrees, where x is the result of the measurement. Going back to your example, the formula for the linear regression of a time series does not have a slope of 0.175 C/decade (+/- 0.012°C/decade). Neither does the computer, or the pages of paper on which the calculation was performed. That slope is the property of the NCDC temperature data. In other words, it is simply incoherent to say the linear regression is a property of the mathematical manipulation rather than the data. It is absurd on the same level as saying "The green dreams slept furiously together". And the reason you are generating such incoherent notions is because you are trying to reify a purely pragmatic distinction. The question you need to be asking is not whether the linear regression is a property of the data set or the mathematical manipulation (trivially it is a property of the data set). What you need to ask is, is it a useful property to know. And, as with any question of usefulness, that depends critically on the use intended.
  18. Still Going Down the Up Escalator
    Tom @125 "I don't know if that is Briggs main point..." It's probably not his main point - I misspoke. He's primarily arguing for the use of predictive statistics, which is not standard in most fields. And because frequentist interpretations are counterintuitive and often unrealistic, he prefers Bayesian predictive techniques. Eli @129, I don't have a problem with a global mean surface temperature. The issue comes with how uncertainty in this value is calculated and viewed, and how a change in GMST is determined.
  19. Still Going Down the Up Escalator
    Robert S is simply Essex and McKitrick dresses in fancy statistical pants. http://www.realclimate.org/wiki/index.php?title=C._Essex_and_R._McKitrick Been there, done that
    Moderator Response: [Dikran Marsupial] Link activated
  20. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    I should clarify: I meant "actual contents", as opposed to "imagined contents" - a couple of reviews seemed to be based on the latter. Oddly enough, the reviews I rated unhelpful were all 1-star, and those I rated helpful were all 5-star. Hmm... coincidence?
  21. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    I had a look at the Amazon reviews, and rated them as to how helpful I thought they were. The ones that didn't actually describe the content of the book, but were full of vitriol (some of which constituted little more than a couple of insults), were rated as 'unhelpful', while the ones that described & commented on the actual contents of the book were rated as 'helpful'.
  22. Still Going Down the Up Escalator
    Tom Curtis @125,126 You're being silly now. Practically, and perhaps physically, we could never measure temperature perfectly. So we can never truly observe "temperature" You're right. From a statistics standpoint, however, the distinction is different. Let's say we have these devices which we'll call "thermometers" that measure, for the sake of simplicity, some quantity called "temperature" (though we both agreed that they don't actually measure temperature). Say we want to measure the temperature of the entire planet. It would be simply unfeasible - or even impossible in practice - to measure every single point on the entire planet, so we place a few of these devices at choice points around the planet, and with the magic of statistics, from these measurements we construct an "average" and an "uncertainty" using some or other method. This "average temperature" isn't an actual temperature which we've measured and neither is the uncertainty; they arise from the method in which we combined our sample. Is our method the true and correct method? Probably not, but we can't say that with absolute certainty. Whether it's a reasonable method is another question. Say we then compute these average temperatures in regular time intervals to find an "average monthly temperature", and we want to see what these average monthly temperatures are doing over some specified time period. So we look up some kind of statistical model, compute it for our average monthly temperatures, and out pops some parameter of that model which we'll call "slope". Is slope a feature of the data itself, or the way in which we manipulated the data to create our model? Is our model the true and correct model? Probably not, but we can't say that with absolute certainty. KR @127 "However: Are you asserting that a trend line cannot be determined (as a statistical evaluation, within stated and computed limits of uncertainty) from the data?" No, of course a trend line can be determined from the data. I might question the value or interpretation of such a metric, but not that one can be calculated. For what it's worth, it's clear that Tamino knows his stats, and he has that rare quality of being able to explain esoteric statistical methods easily to laymen, but his latest post again misses Briggs' point.
  23. Still Going Down the Up Escalator
    RobertS - Fair enough, I have perhaps not been sufficiently clear on the terminology. However: Are you asserting that a trend line cannot be determined (as a statistical evaluation, within stated and computed limits of uncertainty) from the data? I ask because that is the apparent direction of your recent comments. And if this is not what you are asserting - then what is your issue with such statistical analyses? Quite frankly, I'm finding difficult to ascertain your point...
  24. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Pirate: "Ultimately, any reviews of books on AGW (whether from the skeptic viewpoint or the believer viewpoint) are going to be heavily biased." Oh, absolutely. Some reviewers will say that the peer-reviewed consensus science is very likely to be correct, and that it mandates an intelligent response from reasonable people. And others will say that Michael Mann is a lying communist stooge who was sent by George Soros to destroy capitalism, depopulate the world by 80 percent and leave a handful of cave-dwelling survivors to gnaw twigs by the light of phosphorescent lichen. So yeah, these views are equally biased and we can write 'em both off. That's just common sense, right?
  25. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Dale, But since the book looks to be more about Mann's sob story than any real science, I wouldn't have read it regardless. So you don't know what the book is actually like, and you're not at all interested in finding out. Very illuminating. Thanks for sharing.
  26. Still Going Down the Up Escalator
    RobertS @124, tell me the last time you saw a temperature. Indeed, we cannot even detect temperatures with our sense of touch. What we detect is the rate of heat transfer through the skin, and that in non-quantifiable terms.
  27. Still Going Down the Up Escalator
    RobertS @121:
    "I believe Briggs overall point is that the frequentist interpretation of confidence intervals is not intuitive, which begets confusion.
    I don't know if that is Briggs main point, but if it is, well yes (obviously), but they do not introduce anywhere near the confusion Briggs has with his comments. And speaking of which:
    "And that confidence/credible intervals of observables is preferable to confidence intervals of model parameters.
    The distinction being made here is arbitrary, and without any justification in epistemology. As Briggs (and you) are using the distinction, the temperature at a specific time and location is an observable, but the GMST (Briggs) and the linear regression of the GMST over a period (you) are not. However, respectively, the GMST is determinable by an (in principle) simple calculation. It is rendered difficult not by any fundamental issue, but by limitations in the available observational data set. And once you have a time series of the GMST, determining the linear trend is an even simpler calculation with no in principle difficulties. Your distinction appears to be, therefore, a distinction between data obtained by "direct" observation, and data derived by mathematical manipulation of data obtained by direct observation. But as has been noted previously, there are no direct observations of temperature. Rather, we directly observe the length of a column of mercury or alcohol. Or we directly observed the degree of bending of a bi-metal strip. Or we directly observe the current in a circuit (by observing the position of a needle). Converting any of these "direct" observations into temperature data involves calculations just as much as determining the linear regression of a time series. At the most fundamental level, all that is actually observed (visually) is progression of patterns in colours on a two dimensional field. If you are going to make a distinction between observing temperatures, and observing slopes, there is no in principle distinction that will keep you from limiting "direct observation" to that simple descriptions of that visual field (and good luck developing any physics on that basis). In practice we do not make the distinction between what we observe, and what we can know from what we observe except pragmatically (and because pragmatically, based on the needs of particular situations). Briggs appears not to recognize that, and wishes to reify a pragmatic distinction. To which the only appropriate response is, more fool him.
  28. Still Going Down the Up Escalator
    KR @122 Model parameters like slope are, by definition, unobservable. That is, they cannot be measured, observed, detected, identified, and thus, verified in the real world.
  29. Still Going Down the Up Escalator
    In case you haven't seen, Briggs had previously attempted to quantify the credible interval on the observables for the BEST record here, with the result being greatly increased uncertainty in temperature estimates.
  30. Still Going Down the Up Escalator
    RobertS - "Slope in a linear regression of either temperatures or GCM output, however, is still an unobservable parameter" What, in the vast world, are you talking about? That's complete nonsense. Slopes are a completely observable quantifiable (including uncertainties) value (see Tamino on this very topic). you're sounding as bad as Rumsfeld with his "unknown unknowns"... Spatial correlations of temperatures ("a place on the Earth where we haven't sampled") are extremely well established (Hansen et al 1987), and Briggs is simply arguing semantics, not numbers. You have most certainly not presented evidence to the contrary. I look forward to Brigg's further posts. Although, based upon what I've read so far, I don't expect anything beyond a confirmation of his biases, poorly supported excuses, and misinterpretations...
  31. Global Sea Level Rise: Pothole To Speed Bump?
    skywatcher - Agreed; Greenland is a prime candidate for steady increases in ice loss/sea level rise, while Antarctica is a risk for jumps in sea level due to grounded glaciers cutting loose. Either way, folks (are you listening, Steve Case?) rises on the order of 1mm/day are entirely possible, given that warming is something like an order of magnitude faster than anything in the paleo record. And hence, so are the possibilities of sea rise rates. Personally, I'm not encouraging coastal real estate investments for anyone I know...
  32. Still Going Down the Up Escalator
    Muoncounter @107 "In this case there are physical models and they predict a slope that is verified by the observables." When I say "slope", I mean the b quantity in a simple linear regression model y=a+b*x+e. If you want to argue that climate models skillfully predict actual temperature - something your source doesn't attempt to show - or that the slope in a linear regression of temperatures is insignificantly different from that of climate models, that is one thing (exactly what the latter means I can't say for certain). Slope in a linear regression of either temperatures or GCM output, however, is still an unobservable parameter - it's not a measurable, identifiable feature of the data itself, but of your particular model - and cannot be verified. Unobserved observables are quantities which can be measured, but haven't been. So that could be the temperature measured at a particular station some time in the future, or simply a place on the Earth where we haven't sampled. Tom Curtis @108 I agree that a "classical predictive interval" would be similarly wide as a Bayesian interval, and Dikran has indeed shown the credible interval of the regression to be comparable to the classical interval, but I believe Briggs overall point is that the frequentist interpretation of confidence intervals is not intuitive, which begets confusion. And that confidence/credible intervals of observables is preferable to confidence intervals of model parameters. Briggs is part-way through a new series of posts about time series analysis, model selection, and how to treat uncertainty. Maybe it will help clear up some confusion about his position.
  33. Global Sea Level Rise: Pothole To Speed Bump?
    #58: West Antarctica is buttressed by two great ice shelves, the Ross and the Ronne-Filchner. As we have already seen on the Antarctic Peninsula, ice shelves can spectacularly collapse in very short spaces of time, leading to great armadas of icebergs (Larsen A & B, Wilkins - video). If the main ice shelves go, sea levels will suddenly rise much more quickly as the grounded glaciers that are buttressed by the ice shelves accelerate. An interesting paper on a past example driven by warming seas. Ultimately, gradual acceleration is most likely with Greenland (and is observed), while West Antarctica has the potential for more sudden acceleration, but isn't presently losing mass so fast.
  34. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Thanks for writing this, John. Mike M. is a true science hero, and deserves support.
  35. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    pirate#18: "Books of this nature are not going to sway the other side, but may recruit lukewarmers." Consider these January 2012 US poll results: A new Rasmussen Reports national telephone survey of Likely Voters finds that 64% say global warming is at least a somewhat serious problem, including 30% who say it’s Very Serious. That suggests that 34% are in the 'somewhat serious' camp; you might call them 'lukewarmers.' If that large a population might be reached by Mann's book, it is very worthwhile effort. It is also a worthwhile effort to publicize the vile tactics in use by the deniers. "nothing on this issue will be resolved by any amount of posts here. It is an exercise in futility." I am sure there are quite a few folks who have learned a lot from posts here. Is education an exercise in futility? If so, why are you a teacher?
  36. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Just wanted to post another reminder to those folks who will be in Southern California next week -- Dr. Mann will be speaking at the Aquarium of the Pacific in Long Beach (in the greater LA area) on Feb 15. Details here General public admission is only five US bucks. That means that you will have plenty of money left over to buy a copy of "The Hockey Stick and the Climate Wars" for Dr. Mann to sign. Just think of it -- your very own signed copy of "The Hockey Stick and the Climate Wars".... occupying prime real-estate on your coffee table, just waiting for your favorite denier in-law to see it. Then when your denier relative starts ranting about Mann's "hockey-stick fraud", you can open the book and say to him, "Look at this: It's even signed by the author." Then grab a bag of popcorn and watch the show!
    Response: [JC] converted your URL into a hyperlink, it was stretching out my web design.
  37. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    apiratelooksat50@18 "Ultimately, any reviews of books on AGW (whether from the skeptic viewpoint or the believer viewpoint) are going to be heavily biased." Belief is not required when evidence exists. True Skeptics draw their conclusions from available evidence. True Believers dont require facts to base their beliefs on. in other news... I wish I had time to read the book before I go and see him speak at the Long Beach (California) Aquarium next Wednesday. Any other locals planning to attend?
  38. Skepticism About Lower Atmosphere Temperature Data
    Fred Staples @30, are you suggesting that the Hadley Center did not use the data in constructing the graph? Regardless you are using a very simplistic analysis. By eye, the weighting function above 10 Km of the TMT channel represents approximately one quarter of the channel weight. I will use 0.2 to be conservative. From 1979-2002 the positive trend over the altitude range of 0-10 Km has been 0.1 C per decade according to HADAT. Over the same period, the average over the range 10-20 Km has been around -0.5 C per decade. The effect is then that over the whole channel the trend is (-0.5 x 0.2) + (0.1 x 0.8) = -0.1 + 0.08 = -0.02. These figures are of course very inexact. They merely serve to show that looking solely at the relative area of the weighting function to determine the effect on the trend is a gross distortion. It may require 22 years to find statistically significant cooling at 15.75 Kms, but it is still a cooling trend, and a larger cooling trend than the warming trend in the troposphere. Therefore it significantly distorts the TMT channel as a measure of tropospheric temperature trends. Pretending otherwise is nothing but wishful thinking.
  39. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    "In the end, nothing on this issue will be resolved by any amount of posts here. It is an exercise in futility. Energies could be better focused elsewhere. " If "by this issue" you mean "is the book any good?", then I agree. If you mean "is our theory of climate valid", then posts here help those who want to find out what the science says. It wont help those who have made up there minds on an issue from ideological or other biases that are immune to data.
  40. Daniel J. Andrews at 14:37 PM on 9 February 2012
    Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Glad there's a Kindle version. I'll be able to read it while away. John, I did find your review helpful so indicated that on Amazon after I bought the book.
  41. Global Sea Level Rise: Pothole To Speed Bump?
    Skywatcher #55, thanks Mean annual rate of ice mass loss Greenland: 200-300 Gt Mean annual rate of ice mass loss Antarctica: 70-210 Gt Permafrost warming: 0.5°C to 2° Freshening of part of the Arctic Ocean: 2006–08 increase 8400 ± 2000 km3 http://www.aoml.noaa.gov/phod/docs/Goni_etal_2011.pdf I am prepared to worry about either or both but I still don't quite see why Antarctica should be favoured eventhough the WAIS is indeed perhaps more prone to melt at its base. Is there evidence (yet)? In favour of "Artic worries" might be the the permafrost melt run-offs draining into Arctic waters. Am I being obtuse?
  42. Debunking Economic Myths from the Climate Hearing
    Working link. Comparing the Cost
  43. Debunking Economic Myths from the Climate Hearing
    This is the best place I found for this. In the Resources>climate graphics http://www.skepticalscience.com/graphics.php?g=11 the link to Watkiss et al (2005) link does not work on the graphics page. It does work on the graph on this page. Please delete this.
    Response:

    [DB] The correct link is:

    http://ec.europa.eu/clima/policies/package/docs/final_report2_en.pdf

  44. Still Going Down the Up Escalator
    Hi Dikran Marsupial -- does your Bayesian analysis correct for autocorrelation? What you've done is really cool, and is something I should learn how to do! But I wonder if autocorrelation in the series would widen your credible interval.
  45. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Note that there is also a 'Report Abuse' link for each review on the book's Amazon page. Several 'reviews' are indeed abusive and will be removed (eventually) if enough people click that link.
  46. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Dale, I don't see the book as a sob story and that's not what I took from it. I see it as an insight into the tactics of those who oppose climate science and an eye-opener at the sheer weight and longevity of the attacks. You have to read the book in detail to fully appreciate the anti-science campaign that is currently being waged and it is in the public interest that we are all aware of what's happening here. Considering all the crap he's been forced to withstand, Mike Mann is remarkably up-beat and chipper.
  47. apiratelooksat50 at 13:54 PM on 9 February 2012
    Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Dana at 9 and Rob at 7 My apologies. I should have written my post more clearl. I was commenting on this statement from you: "I strongly encourage people to follow John's link to Amazon, read the reviews for yourself, and rate them as you feel appropriate to try and counteract the WUWT behavior." It seemed like you were encouraging people to read and rate reviews and not read the book. If that is a misinterpretation - my apologies again. Ultimately, any reviews of books on AGW (whether from the skeptic viewpoint or the believer viewpoint) are going to be heavily biased. The same reviewers can be found on either side of the demarcation line giving 1 or 5 star reviews depending on their personal views. And, in many cases the the book is never read, or only partially read. For instance, Professor Mandia negative 1-star review on Laframboise's anti AGW book was the following: "...After reading about 50 pages, and it was a struggle to go that far,...". He may have read further, but we honestly don't know. His 5-star review on Mann's book was obviously extensive and glowing. The point is this. People are going to believe what they believe on extremely polarizing subjects like this. Books of this nature are not going to sway the other side, but may recruit lukewarmers. Both sides appear to be actively recruiting positive/negative reviews and helpful/unhelpful ratings. In the end, nothing on this issue will be resolved by any amount of posts here. It is an exercise in futility. Energies could be better focused elsewhere.
  48. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    Dale - have a good look at the title of the book. "The Hockey Stick And the Climate Wars" and the sub-title ..... "Dispatches From The Front Lines". And you were expecting a science textbook? Or what?
  49. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    And bill, it's pretty obvious from @12 that I haven't read the book (and don't intend to due to Mandia's review). If you didn't see that in my post, maybe you need to go to specsavers as skywatcher so eloquently put.
  50. Medieval Warm Period was warmer
    jzk @69, I was about to ask you to pay closer attention to the actual argument made above, which focuses on comparing the regional distribution of the MWP warmth, compared to the global distribution of the warmth in recent decades. That is, I believe, a valid comparison, and a valid point to make from that comparison (with caution). However, on rereading the article I noticed the concluding sentence, which while correct, is not supported by the figures shown. So not only does the article not caution against the invalid conclusion (from the evidence presented) that you caution against, it appears to implicitly draw that conclusion, and needs to be revised. Having said that, the final sentence is well supported by other evidence, notably by Mann et al 2008, which shows these figures in the supplementary data: You should notice that in all three series, the temperature in 1998 (the highest shown in the instrumental series) is greater than the upper confidence limit for the highest decade in the MWP. Therefore, the concluding sentence above (intermediate) level, while not supported by the figures in the article is well supported by scientific evidence.

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