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Comments 74101 to 74150:

  1. Review of Rough Winds: Extreme Weather and Climate Change by James Powell
    The whole question 'what caused weather event XYZ' is inherently flawed. You'll frequently hear 'skeptics' claim things like, 'no it was not global warming, it was El Nino'... seemingly unaware that this claim is just as clearly false as blaming global warming alone would be. If the ENSO cycle were "responsible" for the recent Texas drought/wildfires, Mississippi flooding, hurricane Irene, massive tornadoes, et cetera (as many 'skeptics' confidently proclaim) then we would see these events during every ENSO cycle. We do not, because weather is never 'caused' by just one thing. The very concept of the 'butterfly effect' demonstrates this... it argues that in a chaotic system (like Earth's weather) small changes (like a butterfly displacing air by flapping its wings once) can cause large deviations (like a hurricane which would not otherwise have occurred). The aspect of the concept which many people seem to miss is that there are ALOT of butterflies in the world. Along with billions of other things which influence the weather. If a different butterfly on another continent gets hit by a car that could prevent the butterfly-hurricane from forming. Ditto a cloud drifting between the sun and an area of blacktop and thus preventing a thermal updraft from forming. Et cetera. ENSO, like global warming, just makes certain kinds of weather more likely. It does not 'cause' them entirely on its own any more than global warming does because all weather events are caused by the collective action of billions of factors. That being said, global warming has changed the climate of the entire planet. Some butterflies which would not be alive had AGW not taken place are... others have died because of AGW. Evaporation, clouds, precipitation, albedo, and dozens of other factors have changed the world over. Thus, it could be reasonably said that ALL weather we see now is due to global warming. It is all an aspect of the current climate, which has been changed by AGW. Thus, I can guarantee that if the past 150 years or so of global warming had not taken place Hurricane Irene would not have happened exactly the way it did. It could have been nice and sunny... or there could have been an even worse storm, but that exact weather event would not have taken place. Far too many of the 'butterflies' which contributed to the way it played out were changed by AGW. So really, as the article above also notes, the only meaningful metric of the 'effect' of global warming (or ENSO) on the weather is a change in frequency of various types of events.
  2. Antarctica is gaining ice
    DB I see that the responses to the comments in question have been updated and the whole thing makes perfect sense now. Tone trolling should rightly be ignored, but IMO Bishop Hill did have a point, although they vastly overstated the significance of it. That Sks is coming under fire presumably means you're doing a good job, so keep it up!
  3. Lessons from Past Climate Predictions: IPCC AR4 (update)
    The more serious problem with this article in my view is the quoting of trends without error estimates, or indeed at all. If an undergraduate quotes a trend in a lab report without a standard deviation, uncertainty interval or P-value, we have to mark it down, and rightly so. And if we calculate uncertainties on the any of the ITRs over the last 11 years what do we find? IIRC we can't distinguish between then, or between them and the 4AR estimate, or between them and the no-warming case. (Sorry, I should check that, but I don't have my code to hand. Bear in mind to get the right answer you have to factor in the autocorrelation - both Lucia and Tamino have written on this at length, but as a crude estimate multiply the OLS estimate of standard deviation of the gradient on the monthly data by 2.5. As a sanity check, calculate 12 month and 22 month non-overlapping averages for the 11 years and calculate a gradient on the averages - you should get roughly the same uncertainties in each case.) That's ignoring the uncertainty in the 4AR projections, which is substantial. Visually, you can draw a whole range of gradients, including negative ones, within the uncertainty bounds. Factor in that and the whole exercise is completely meaningless. What is the correct way to present an discussion of the 4AR predictions, given that there isn't enough data to draw any real conclusions? Maybe we can have a constructive discussion of that? What I would do is plot the AR4 data with the uncertainty intervals from 1990-2020, and plot the ITR moving average on top of it. For reasons stated above I still prefer GISS, but you could plot all three. Ideally of course this would be updated annually. Something like this figure from the Monckton article "IPCC overestimate temperature rise": The other thing that is missing, which formed an important part of some of the other articles is a comparison of the emission predictions - both GHGs and aerosols, and also discussion of which scenarios are most realistic and why.
    Moderator Response: [grypo] Real Climate also used a similar method.
  4. Review of Rough Winds: Extreme Weather and Climate Change by James Powell
    I love the graphic - it reminded me of something... http://lazarus-on.blogspot.com/2011/01/what-is-one-degree.html Don't worry, I didn't try to copyright it. In fact I wish I could have stolen it for my own use.
  5. Lessons from Past Climate Predictions: IPCC AR4 (update)
    I'll write two responses on this. In this first one I'm going to disagree with Lucia and Carrick on the problems of polar temperatures in the ITRs. This is speculative and of general relevance rather than specific to this post, but I think there is a good basis for arguing that the GISTEMP approach is less biased than HADCRUT or NOAA. This is a good topic for further study. In the second I'll suggest why I think the article above still needs a rewrite. So, polar temperatures. Everyone is familiar with the concept of polar amplification? Here's a figure from U Columbia, although we should really recalculate it without NASAs interpolation: . Clearly the arctic at least is behaving rather differently than the rest of the planet. Again, as a further check we would want to do some sort of test of sensitivity to choice of stations, cross validation, bootstrap etc. If we use the HADCRUT/NOAA method of simply omitting the arctic, then that is the same as saying the the arctic is behaving as the average of the rest of the planet. That doesn't look like a good starting hypothesis to me. Doesn't it seem more likely that the N pole is behaving more like the nearest arctic stations, rather than postulating a another inflection with latitude? Another interesting experiment would be to calculate a global temperature from Nick Stokes' spherical harmonics in the latest version of TempLS. My guess is that these will show a higher trend than GISTEMP, because I suspect the pole will show as a peak. If might be possible to test whether it is physically meaningful by cross validation.
  6. Antarctica is gaining ice
    Given the concerns on Bishop Hill I would suggest that Sks remove comments 3, 5 and any other early comments that were replying to this post before it was updated to make a definite distinction between land and sea ice. If Sks did, for example, write the response to comment 3 after updating the post, then (-Accusations of dishonesty snipped-), when it actually seems like they were pointing out that the original incarnation of this page was unclear and certainly incomplete. I hope the Sks team sees my point. Our 'side' of the debate is by far the stronger, supported as it is by the weight of peer-reviewed science, and so there need be no reliance on misinformation, no matter how small a nugget of misinformation it is. Therefore all humility and reticence must be shown on sites like Sks, and things like this that have been overlooked must be corrected. Not doing so risks giving those of an anti-science persuasion an excuse to focus on something other than the science! Of course, the current incarnation of this page is an excellent description of the state of Antarctic ice, no problems there.
    Response:

    [DB] Accusations of dishonesty snipped.

    "Therefore all humility and reticence must be shown on sites like Sks, and things like this that have been overlooked must be corrected."

    SkS endeavors to keep its focus on the science, not on rhetoric, ideology or invective.  Hue and cry from the "skeptics" on things transparently not based in science amount to little more than tone trolling and are typically ignored.

    However, your point is made, taken and noted.

  7. The 2nd law of thermodynamics and the greenhouse effect
    Re #288 [trolling snipped] Moderator Response: [Dikran Marsupial] you wrote:- "It is not acceptable for any poster to disrupt the discission in this manner" Dikran, I just do not agree with your physics.
    Moderator Response: [Dikran Marsupial] Note yet again I have pointed out your error (I did specify what kind of temperature measurement I discussed) and again you do not acknowledge your error (if it was me I would have appologised - we all make mistakes, it is no big deal, unless you can't acknowledge them, in which case you have entirely the wrong attitude for scientific discussion).

    If you don't agree with my physics, just possibly it is because your understanding of the phycics is wrong, rather than that of the worlds climatologists and physicists. However you will convince nobody that your position is correct if you conduct the discussion in the manner that you have chosen.

    To be clear, we welcome a discussion of the physics, but not constant repetition of arguments that have been refuted repeatedly already on this thread and on others, without addressing those refutations
  8. The 2nd law of thermodynamics and the greenhouse effect
    Re #283 Moderator Response: [Dikran Marsupial] you wrote:- "you that was arguing that CO2 in the atmosphere has no effect on temperatures not me" With thermodynamics you have to be precise, What temperature are you referring to when you speak of a planet's temperature? [trolling snipped]
    Moderator Response: [Dikran Marsupial] Sorry this is blatant trolling. I specified mean surface temperatures (I have put it in bold now to make it more obvious), so I specified exactly what I meant. Enough is enough, if you continue in this manner I will reluctantly recommend that your posting privelidges are rescinded. It is not acceptable for any poster to disrupt the discussion in this manner.
  9. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Albatross: I'm afraid nit picking is not constructive, especially when the nits have no basis or are in error. I hope to see you acknowledge your own mistakes (we all make them, no shame in that) and correct your blog post too (if needed) so as to keep you readers informed. Best, Albatross. Just because you assert this doesn't make it so. There is nothing "nit" in the points that Lucia has made. 1) Dana has chosen the highest of the three surface temperature records to compare against. This is a fact not a nitpick. 2) While there is an argument for using GISTEMP, it's not a very good one...GISTEMP relies on an untested method for extrapolating temperatures into the high Arctic, one that is is likely wrong. 3) Further there is an inconsistency in methodology here: Dana uses the average of the models, which is not actually a defensible thing to do, but selects out a single temperature series (the one with the most rapid growth in temperature, [inflamatory deleted]) to compare against as the "exemplar" that other temperature series must live up to. 4) By innocently selecting 2000 as his starting year, he's front-loaded his data with a low-valued extrema, which has a substantive effect on the temperature series. 2000 was in the throes of a La Nina cooling event, he either needs to correct for this (see how on Lucia's or Tamino's blog), or he needs to shift his starting point to 2001. Doing this latter operation changes the slope from 0.15°/decade to 0.074°C/decade. 5) He needs to use consistent baselines in making the comparisons. A factor of two isn't a "nit". Picking a starting year that contains an outlier isn't a nit. Using inconsistent baselines is not a nit. And by the way 2001 is the start of the decade, not 2000, so the "we picked 2000 to represent the start of the decade" argument doesn't fly either. If you want my recommendation [inflamatory deleted] I would use the mean of the temperature series if you're going to compare to the mean of models. It's at least a consistent treatment. Here is my own version of Dana's graph. It clearly labels the "verification period" (where data was available to compare the models against, which ended in 2004 for AR4) versus the "validation period" (where data were not yet available, but are now) I don't personally make a huge deal of the disagreement between model and data over that period, other than to state it exists. [inflamatory deleted]
    Moderator Response: [Dikran Marsupial] While constructive criticism is very welcome here, posturing and inflamatory statements are unhelpful and should be avoided, by both sides of any disagreement.
  10. It's the ocean
    Dana69 - See SkS post: Ocean cooling corrected, again And note the warming oceans down to 1500 metres:
  11. actually thoughtful at 16:04 PM on 23 September 2011
    SkS Responses to Pielke Sr. Questions
    Response to moderator comments @182 John Hartz - yes there was muted appreciation for Dr. Pielke's presence here, surely you would agree that a very public (as in posted on his blog site if he allows comments anywhere) thank you from John Cook (as the man behind SkS) would be a class move (or directly to his email if he doesn't allow comments anywhere). Perhaps this has been done. I do NOT subscribe to the false equivalence of deniers and scientists, however I do accept that Dr. Pielke has studied this stuff for a lifetime, and I think his presence on this site is a credit to John Cook and other long-time SkS folks - you have created a site where Dr. Pielke wants to present his case. As far as how it might seem to Dr. Pielke - imagine if you were invited to present/defend a post on WUWT - you might have trepidation (and again, I am not presenting any false equivalence between WUWT and a real science site like SkS). You can thank him for his participation and not dwell on his departure. Daniel Bailey - your internet-as-the-great-equalizer is, in general, a great perspective. I personally was thrilled/humbled when Dr. Trenberth wrote a post on SkS - but I didn't think my post was in any way as important or informative as Dr. Trenberth's. While I don't disagree with Dr. Pielke's science (in so far as I understand it), I still wonder what the fuss is about. He could say "well we need to reduce CO2 regardless" and be consistent with his science, he appears to enjoy controversy for controversies sake (the whole non-dichotomy of option 2A and 2B being a case in point). So, given that I disagree with his conclusions (me short for Pielke shorter: "lets obfuscate instead of acting") I still think he should receive the same respect that Dr. Trenberth received. While of course all posts here (at least after moderation) were at a reasonably high level, I could feel a very different attitude towards Dr. Pielke, perhaps due to the difference in their scientific positions. Mainly I thought the wall of posts/questions would be hard for anyone, let alone someone out of his comfort zone, to respond to in a useful way. It comes down to whether you put "internet equality" ahead of truly understanding Dr. Pielke's position. As many have noted, a blog comment section, as currently structured, is not the optimum forum for that. Thus my original comment at 182. I personally don't think internet equality applies when you have invited a person noted in their field to your site. They should be at least the first among equals, if not given a different/special platform for communicating their opinion. Now if Dr. Pielke wants to comment on a thread he is not featured in, I certainly agree that his posts should be treated exactly like everyone else. But it feels impolite to invite him over for tea (as it were) and then ambush him (again, no bad intentions, just what the medium creates) with endless questions, counters, etc. For the sake of clarity: I don't think Dr. Pielke's reference to papers he has written was particularly helpful (nor his apparent evasion of direct, germane questions), but I do think he deserves a charitable viewing of his argument, especially after SkS invited him over.
    Moderator Response:

    [DB] Thanks for the perspectives; thoughtful as usual.

    My point, distilled, is that all are held to the same standard here.  Many comments were deleted from the thread, but none of RPSr.  Though perhaps many should have been.  So claims of unfair moderation may have some truth in that everyone else here was held to a higher standard of conduct than RPSr.

    [John Hartz] I'm not aware that "many" comments were deleted from this thread. Perhaps you are referring to the thread of Dana's initial article where many commenst were in fact deleted?
  12. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Hello Lucia, Welcome to SkepticalScience. I'm very sorry that you have some misgivings about this site and even some suspicions it seems, but please do not be so quick to judge. We appreciate that you assisted earlier in identifying flaws, it is important to get things right and Dana corrected the error lightning speed. While we welcome your opinions, I'm afraid that your minor points have their own issues: "a) Included other observational data sets like HadCrut and NOAA. (If s/he thinks they are inferior GISTemp, s/he should say why he thinks so.)" What Craig said @12. I think that you know as well as we do that each of the datasets has its limitations. What do you think is the best GAT analysis and why? Dana was simply being true to the original graphic that was shown. "b) Discussed whether the comparison in his figure ends with an El Nino year vs. La Nina year. (BTW: If the observations ends with 2010, it ends with an El Nino). The models average over numerous cases so its not important for the models but it matters for the observations." As it happens that is not quite as straight forward as your presume, because 2010 was a transition year. The CPC ONI data show that El Nino conditions persisted until April, with a short window of neutral conditions, followed by the formation of a La Nina in JJA. So while the impacts on global SATs would have potentially lingered for 5 months or so after the El Nino, is is not strictly correct to say that "If the observations ends with 2010, it ends with an El Nino" as you did, 2010 actually ended in a strong La Nina. Besides, as noted by Alex @11, the trend was calculated through mid-2011. "c) Mention the exact year when the AR4 was published rather than merely saying it was published "recently". After mentioning the year, he should explain why his comparison starts in 2000. (Whatever the reason for his choice, he should give it.)" Please read the first sentence of the post. It starts"In 2007, the IPCC...". Also, the year appears in a light blue banner in some of the pages linked to, or in the case of the very first hyperlink to "Chapter 8", the following is also printed at the top of the page: "Climate Change 2007: Working Group I: The Physical Science Basis". I'll let Dana explain why he starts in 2000-- it probably has something to looking at decadal trends. I'm afraid nit picking is not constructive, especially when the nits have no basis or are in error. I hope to see you acknowledge your own mistakes (we all make them, no shame in that) and correct your blog post too (if needed) so as to keep you readers informed. Best, Albatross.
  13. Lessons from Past Climate Predictions: IPCC AR4
    I'm reminded of this one just a few days ago, Dana. Anthony Watts: "Oh dear, now we have three peer reviewed papers (Lindzen and Choi, Spencer and Braswell, and now Richard P. Allan) based on observations that show a net negative feedback for clouds, and a strong one at that. What will Trenberth and Dessler do next? Maybe the editor of Meteorological Applications can be persuaded to commit professional suicide and resign?" Bart summarized the incident here. What's remarkable is the above line by Watts remains in the post, shrillness and all, long after some, including the author of the paper he's botching, corrected him. Strange.
  14. Lessons from Past Climate Predictions: IPCC AR4 (update)
    lucia - you are of course entitled to your own opinion, but your own opinion seems to consist of whole bunch of nitpicks [you should have explained 'x' and 'y']. There are a million things I 'could have' explained, and what I 'should have' explained [especially your examples] is extremely subjective. You also might want to read the second word in the post, and also the title of Figure 3. I'm relieved to see that I'm not the only one who makes errors.
  15. Lessons from Past Climate Predictions: IPCC AR4
    skywatcher - agreed, there's a serious difference in the standards each "side" is held to. We make a minor error and it's immediately a "-gate". "Skeptics" make huge errors misrepresenting research or doing bad statistics, and basically aren't even held accountable.
  16. Lessons from Past Climate Predictions: IPCC AR4 (update)
    About -> Team might be useful for Lucia going forward. I'm glad that she is finally beginning to familiarize herself with Skeptical Science.
  17. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Lucia, The post is about the IPCC AR4 projections (as described in chapter 10.3 or the AR4 report) and their accuracy. Figure 2 is the second figure in that report. It presents GISS data up to the year 2000 and model projections from there until 2100. Had the IPCC plot used one of the other instrumental records or a different cut-off between the observational and modelled data then it would make sense for Dana to have used those. But that isn’t the case. Seem pretty obvious to me. The IPCC AR4 report was published in 2007 (it states it on the report!). Is that relevant?
  18. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Lucia: The general reason for consistently using GISTEMP is that it is a truly global dataset, whereas HadCRUT is not for instance (it excludes the poles). I am not personally sure about NOAA. As to your other two points, you may want to recheck the first line of the article, and also where Dana stated that the trend calculated from GISTEMP was through mid-2011, which so far has been La Nina.
  19. Lessons from Past Climate Predictions: IPCC AR4
    Charlie A was on the right track, and asked the key question, but his reasoning wasn't quite right, and that may have caused Dana to chase a red herring. "I see a slope of 0.2C/decade, not the 0.12C that you see." IPCC AR4 Synthesis report says "For the next two decades a warming of about 0.2°C per decade is projected for a range of SRES emissions scenarios."" "Seeing" isn't too precise, and 0.2 C per decade is only the quoted decadal rate through 20 years. Zeke's post (#25) was the most useful, Lucia's over-dramatic point-scoring not particularly useful, but I'm pleased to see a variety of blogs paying attention to SkS now.
  20. Lessons from Past Climate Predictions: IPCC AR4
    I wonder if we'll see similar corrections for errors in posts at places like WUWT, when spectacular errors are pointed out. Say... like the errors in arctic temperature data presented at WUWT pointed out by Tamino here, here and here in the past few days, for example? Or perhaps a post or two by Lucia exposing and damning those very large errors and damning the lack of correction or retraction of teh associated claims? It's a serious problem that when relatively minor errors are pointed out in places where the consilience of evidence is accepted, there is a massive fuss about them, whichever direction the errors go, and regardless of whether the errors are pointed out by those who agree with the consensus or those who disagree. Alternatively, complete garbage is regularly published in places that disagree with the consensus on AGW, and yet we hardly hear a cheep from those who obviously should know better.
  21. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Lucia... Please note that Dana is a man. No need for further "s/he" references.
  22. Lessons from Past Climate Predictions: IPCC AR4 (update)
    To be fair, Lucia wrote a blog post on the subject before I updated the post, and maybe even before she commented here. Then again, she could have just commented here noting the problem without writing a blog post, in which case, as we found out, the problem would have quickly been corrected.
    I commented here then immediately wrote the blog post. The issue of Skeptical Science revising posts and the blog owner seeming to forget this has happened and then inserting inline replies happens to be a 'live' topic at blogs. Under the circumstances, I judged posting immediately the most appropriate thing to do under the circumstance and I still judge it so. As it stands, people witness first hand how you responded. Had I done otherwise, they could not witness this. This was part of my motive. The other motive is to host discussion of features of your blog post-- and as you can see from my previous post, I have opinions on issues beyond the mistake in the computation of the trend.
  23. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Albatross-- My post was probably written and published before Dana posted any thanks. Don't let the time stamps fool you - it's still Sept 22 in my time zone. I'm glad to see Dana acknowledged the corrections -- including Charlie A. But it happens that I don't think the miscalculation of trends digitization is the only flaw here. I happen to think Dana should have a) Included other observational data sets like HadCrut and NOAA. (If s/he thinks they are inferior GISTemp, s/he should say why he thinks so.) b) Discussed whether the comparison in his figure ends with an El Nino year vs. La Nina year. (BTW: If the observations ends with 2010, it ends with an El Nino). The models average over numerous cases so its not important for the models but it matters for the observations. c) Mention the exact year when the AR4 was published rather than merely saying it was published "recently". After mentioning the year, he should explain why his comparison starts in 2000. (Whatever the reason for his choice, he should give it.) Of course Dana is not required to do all these things particularly since Skeptical Science is a blog like any other. But it's hardly fair to complain that people at other blogs are expressing their opinion on these shortcomings merely because Dana did acknowledge that someone people found obvious errors in his first post and brought them to his attention.
  24. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Since critics will be linking to the original post, it would be worth adding a note there which points out that this revised version has been posted.
  25. Lessons from Past Climate Predictions: IPCC AR4
    Crosspost: The text in my above post @ 40 should probably read: "Sadly I see that this incident is already being distorted and spun in certain quarters-- and that after Dana graciously thanked them for their feedback." Regardless, it certainly seems that some people are trying to use the situation to their advantage.
  26. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Fair point Dana, The text in my above post @ 4 should probably read: "Sadly I see that this incident is already being distorted and spun in certain quarters-- and that after Dana graciously thanked them for their feedback." Regardless, it certainly seems that some people are trying to use the situation to their advantage.
  27. Lessons from Past Climate Predictions: IPCC AR4 (update)
    To be fair, Lucia wrote a blog post on the subject before I updated the post, and maybe even before she commented here. Then again, she could have just commented here noting the problem without writing a blog post, in which case, as we found out, the problem would have quickly been corrected. To each his (or her) own. I hope the matter is now considered resolved.
  28. Lessons from Past Climate Predictions: IPCC AR4
    From another thread here at SkS: "Sadly I see that this incident is already being distorted and spun in certain quarters-- and that after Dana graciously thanked them for their feedback. Must be desperate times and/ or a slow week for "lukewarmers" and 'skeptics' if this is something that gets them so excited. "
  29. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Sadly I see that this incident is already being distorted and spun in certain quarters-- and that after Dana graciously thanked them for their feedback. Must be desperate times and/ or a slow week for "lukewarmers" and 'skeptics' if this is something that gets them so excited.
  30. Lessons from Past Climate Predictions: IPCC AR4 (update)
    I'd like everyone (especially critics and 'skeptics') to note four things here: 1) The error has been acknowledged 2) The error was corrected with lightning speed 3) The people who identified the error were thanked and their names highlighted at the top of the post 4) The correction did not change the primary point or conclusion of the post, as far as I can tell.
  31. Lessons from Past Climate Predictions: IPCC AR4
    Wow I didn't even have to wait until morning. Lucia sure is quick on the draw.
  32. Lessons from Past Climate Predictions: IPCC AR4
    Thanks skywatcher - I'm sure I'll be lambasted anyway! It seems like certain parties are looking for any excuse to lambast SkS and myself these days. I view the increased scrutiny as a sign that SkS is becoming more effective, and the lambasting as a sign that we're viewed as more of a threat. It's a compliment really :-) It will be interesting to wake up tomorrow and see how many 'skeptic' blogs have posts about me making a minor (I mean, ginormous!) error.
  33. Lessons from Past Climate Predictions: IPCC AR4
    All good by me, thanks Dana! You've done a great job on a lot of posts here, and I didn't want to see you lambasted for any problems with this one.
  34. Lessons from Past Climate Predictions: IPCC AR4
    skywatcher - fair enough, I've added a hat tip to Charlie as well, though I still don't interpret his comments in the same way. But I don't mind adding an acknowledgment that he raised initial concerns about the quality of the digitization, and have done so in the updated post. lucia - please tone it down. The quote you reference is in regards to Figure 3. Charlie questioned the accuracy of the 0.12°C trend, and rightly so. His claims of a 0.2°C trend, however, were in reference to the 2000 to 2020 trend. I've acknowledged and corrected the problem. Can we move on now please?
  35. Lessons from Past Climate Predictions: IPCC AR4 (update)
    Whoops thanks Alex, a holdover from the previous version.
  36. Lessons from Past Climate Predictions: IPCC AR4
    Dana, I think you should acknowledge Charlie A in the updated post as well as Lucia and Zeke. My reading of Charlie A's comments is that he was correct in his observations, pertaining to the 2000-2010 part of your Figure 3. The data provided by Zeke and Lucia merely confirm that. As I've found to my cost before, digitising images is a tricky business, especially if the scale of the original is small! Obviously, it doesn't alter several facts - first, that the AR4 projection is so far doing a perfectly reasonable job of estimating warming, though as you say it is very early to judge; and second that the trend present through the 1990s actually increases if you include the last 10 years of data, even though the trend for the last 10 years alone is slightly lower (as Robert notes in #18) - highlighting the caution with which one should apply value to short-term trends and the strength of longer-term trends.
  37. Lessons from Past Climate Predictions: IPCC AR4
    Dana-- to 2010 ??" I really don't know how you misunderstood this. But blog comments being what they are, I'm willing to believe you did. My interpretation is that he also points out that your trend also disagrees with the trend for the longer period. This additional information ought to have given you pause and motivated you to double check your digitization or computation. Even just reviewing figure 10.4 which you digitized and noticing the small curvature ought to have given you pause. As for the recentness of the AR4: It was published in 2007-- four years ago. I don't know if that's counted as recent or ancient these days. My understanding is it will be superceded by he AR5 pretty darn soon. The age of these things needs to be translated into dog-years.
    Response:

    [DB] "As for the recentness of the AR4:  It was published in 2007-- four years ago. I don't know if that's counted as recent or ancient these days."

    Dana1981 was speaking from the perspective of having published posts recently on the FAR, SAR and TAR.

  38. Lessons from Past Climate Predictions: IPCC AR4 (update)
    The caption in Figure 3 reads since 1990, but the data shows from 2000.
  39. It's the ocean
    Seems like the oceans aren't increasing in heat. What does this do to the AGW theory? Dr. Trenberth's 2009 lament that: "The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't.. Our observing system is inadequate." Note that Dr. Trenberth doesn't seem to countenance the possibility that the whole anthropogenic thesis - that the climate is driven by man-made industrial emissions - might be wrong. It is the absence of the real world to follow the models that is the alleged "travesty." "Subsurface temperature trends in the better-sampled parts of the World Ocean are reported. Where there are sufficient observations for this analysis, there is large spatial variability of 51-yr trends in the upper ocean, with some regions showing cooling in excess of 3°C," http://journals.ametsoc.org/doi/pdf/10.1175/JPO3005.1 A cooling ocean would falsify the validity of the AGW radiative forcing theory.
    Response:

    [DB] "Seems like the oceans aren't increasing in heat." and "A cooling ocean would falsify the validity of the AGW radiative forcing theory."

    Except for a lack of evidence to support those assertions.  Trenberth's most recent paper shows significant sequestering of OHC from the upper ocean into the deep ocean.  Coupled with Hansen's aerosol forcings hypothesis, the global energy budget appears to likely close.

    A refocus on science rather than unsubstantiated speculation would be of help to you.

  40. Lessons from Past Climate Predictions: IPCC AR4
    DB--Thanks.
  41. Lessons from Past Climate Predictions: IPCC AR4
    lucia, if you read the next line in Charlie's comment, he's referring to the text in the AR4 stating that the trend from 2000 to 2020 is 0.2°C per decade. I will say that if I'm misinterpreting Charlie's comments, and if he was saying the trend from 2000 to 2010 in Figure 2 looked closer to 0.2°C per decade, then he was approximately right (and if that's the case, he's got some impressive eyesight). That's just not how I read his comments, but I could be wrong. As I note in the updated post, our digitization of the graph was unfortunately not very accurate, due to the small scale of Figure 2. That's my mistake - I should have thought to look for a data file, since the AR4 was published so recently, rather than relying on the digitization. Mea culpa on that one, and again, thanks to you and Zeke for pointing me to the data.
  42. Lessons from Past Climate Predictions: IPCC AR4
    Dang-- No preview or edit function on comments. "is NOT 0.21 C/decade." should read "is not 0.12 C/decade".
    Response:

    [DB] "No preview or edit function on comments"

    A 'Preview' button may be found immediately to the right of the 'Submit' button.  The Previewed comment will then appear below the comment box.

  43. Lessons from Past Climate Predictions: IPCC AR4
    Dana
    ucia - Charlie's comment was about the 2000 to 2020 trend. This post doesn't address the trend beyond mid-2011.
    Charlie specifically askes you about the trend from 2000-2010 and does so repeatedly. In comment 1:
    Are we to understand that 0.12C/decade is the trend for the projection for A2 scenario from 2000 to 2010 ??
    The correct answer should be "whoops. No. The trend for the projection for the A2 scenarios from 2000 to 2001 is NOT 0.21 C/decade. In his second comment (numbered 3 here) he writes
    I do not see how it is possible that the slope from 2000 to 2010 is 0.12C/decade. I see a slope of 0.2C/decade, not the 0.12C that you see.
    Note the dates: 2000 to 2010. The correct response is that the slope from 2000 to 2010 -- the dates charlie mention quite specifically-- is not 0.12 C/dec. Charlie is correct to not "see" this slope. Charlie-- who, I should say appears to be being stupendously polite for a blog visitor even asks you to check the trend from 2010-2020 and you answer
    Charlie - yes, the AR4 Scenario A2 model mean trend between 2010 and 2020 is close to 0.28°C. Figure 3 includes the Figure 2 data between 1990 and 2000.
    Your answer is incorrect. The A2 trend from 2010-2020 is not close to 0.28C. You bungled this. You waved away charlie. I don't know where you went wrong, but you messed up. I should think your re-write should acknoweldge that charlie a) was correct b) was obviously asking about the trend from 2000-2010, specifically calling out these years. Or course, you are not required to do this. But, your notion that Charlie was only discussing 2000-2020 is absurd.
  44. Lessons from Past Climate Predictions: IPCC AR4
    lucia - Charlie's comment was about the 2000 to 2020 trend. This post doesn't address the trend beyond mid-2011. I got the data from Zeke's link, and have a new figure. Will post an update shortly.
  45. The 2nd law of thermodynamics and the greenhouse effect
    Philippe and DB, that would be about as exciting as watching an iron ball rust, but the physical model that such a conversation would generate would be an all-time classic. Ok, ok -- I'm tempted, but DNFTT it shall be.
  46. Lessons from Past Climate Predictions: IPCC AR4
    dana-- Will your update acknowledge that Charlie A was correct and you were incorrect about the correct magnitude of the trends?
  47. CERN - Saying Nothing About Cosmic Ray Effects on Climate
    tblakeslee#89: "long list of authors on that paper. Almost like a petition signed by many supporters." No. All high energy particle physics papers have a large number of authors. It is standard practice in that highly collaborative field, where experiments are designed by one team, run by another and interpreted by a third; a process that sometimes lasts many years. "Alfven won the Nobel prize ... so his work was ignored by the establishment." Interesting. Did you see this month's update from the ACE satellite team? It's about how quiet the sun was through 2010, concluding thus: We know of no dynamics that can accomplish this reduction other than magnetic reconnection below the Alfven critical point. So, multiple authors does not a petition make. Alfven? Not ignored. Let's stick to facts from this point forward.
  48. Lessons from Past Climate Predictions: IPCC AR4
    #20 - Paul, lovely chart! A very original way to demonstrate an important principle about cherry-picking trends. Some less- and more-experienced visitors to this site (including me) could learn a thing or two from it.
  49. Review of Rough Winds: Extreme Weather and Climate Change by James Powell
    Adelady, I caught that Catalyst episode more by accident than intention and thought it was quite interesting for it's relevance to ocean mixing as much as wave impacts on coastlines. IIUC much of the acceleration of Antarctic ice loss is attributed to warmer ocean temperatures eating away at the edges and reducing how much glacial flows are held back at those edges; would this data indicate the Southern Ocean would have less sea surface warming during summer (warmer surface water mixed deeper) and greater transport of heat out of the ocean during winter (colder surface water mixed deeper)? Presumably bigger waves impacting the Antarctic coast could also change the rates of ice shelf and glacial terminal disintegration both directly by wave energy and indirectly by more rapid mixing and circulation of melt and ocean water near to the coast. In any case the length of time the study covers could be too short to be more than suggestive of a solid trend of such impacts. It will be interesting to hear some reactions to this study.
  50. CERN - Saying Nothing About Cosmic Ray Effects on Climate
    89, tblakeslee, Do you have any actual evidence of this supposed conspiracy to squelch the advancement of science? [Which, by the way, is a clear violation of this site's comments policy?]

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