realclimate on Loehle

RealClimate has a good discussion of problems with Loehle 2007: link, linking to JEG’s discussion but not to discussion here. Update: Luboš has a discussion here.

In some cases, RC non-linking to climateaudit is mere pettiness, but, in this particular case, they cite information on Loehle that was initially made available at climateaudit. In this CA post, we discussed discussed the provenance of Loehle proxies and requested that Loehle provide his proxies as used – which he provided. The numbering in this article (which differs from the original article) is the numbering used in the real climate article, which they have explained to have derived from the proxy version supplied to them by Loehle, which is presumably the same version that we had requested. Loehle’s article did not include data citations for the Loehle versions. Exact data citations are provided in the CA post here ; Gavin uses exactly the same data citations and has not suggested that Loehle sent him the data citations. While the data citations could be developed independently, in this case, I doubt that Gavin can honestly say that he did not incorporate CA information on Loehle proxies.

For reference, plagiarism (Wikipedia) includes:

… incorporating material from someone else’s written or creative work, in whole or in part, into one’s own without adequate acknowledgement.

Having said that, there are useful analyses of individual proxies – a type of analysis that I, for one, welcome and believe to be relevant, including some caveats on individual proxies that have not been previously raised here. The post is a “climate audit” type of post and shows that Gavin can be a pretty good “climate auditor” when he turns his mind to it.

However, given that 9 of the 11 Moberg low-frequency proxies are used in Loehle 2007, presumably most of these criticisms were equally applicable to the prior use of these low-frequency proxies in Moberg et al 2005 or for that matter in Juckes et al 2007.

My take on Loehle 2007 has been (and I hope that this has been understood) that it is really a variation on Moberg and it’s pretty hard for me to see a rational basis on which Moberg is qualified for inclusion in spaghetti charts while Loehle isn’t. If you go through the RC critique of Loehle, my impression is that virtually every criticism can be leveled equally fairly against Moberg – raising the question as to why RC is only now raising these issues.

Some nits are pointed out in Loehle methodology. I haven’t checked the correctness of these points. And I definitely endorse the idea of realclimate (or anyone else) checking for defects in data handling and reporting. However, they would be a little more credible if they dealt with the many beams in their own eye, such as, for example, the incorrect geographic locations of the Mann et al 2007 precipitation series.

While I am mostly in agreement with their proxy comments, I am not in agreement with their views on multivariate methodology. I don’t have time to discuss this today, but Mann’s present RegEM is not an obvious panacea. It’s hard for a statistical method to be sufficiently bad as to be “wrong”, but Mann has accomplished this twice with the MBH data set: first with the MBH98 PCA-regression combination with its erroneous PCA method; more recently, with the Rutherford et al 2005 RegEM method (the code for which has now been expunged from the record). The new Mann RegEM method gets the same results as these two erroneous methods (a bristlecone-pine shaped Hockey Stick). Is the new method “right”? Readers should recognize that all that is done in these long-winded statistical efforts is choose weights for the individual proxies. The new Mann method does not report the weights assigned to bristlecones, but you can be sure that it is large.

Their comments on multivariate methodology appear weak to me, but the comments on individual proxies are well worth reading. But what’s sauce for the goose is sauce for the gander and surely apply equally or even more so to Moberg.

234 Comments

  1. Sam Urbinto
    Posted Dec 7, 2007 at 12:12 PM | Permalink

    The word hypocritical comes to mind.

  2. steve mosher
    Posted Dec 7, 2007 at 12:18 PM | Permalink

    I have to see if gavin posted my benign question? BRB.

  3. steve mosher
    Posted Dec 7, 2007 at 12:29 PM | Permalink

    Glad gavin posted on it.

    I asked gavin this.

    1. could he give me a list of the 5 proxies that he thought could be used
    2. What would his opinion be of reconstructions that used any one of the remaining 13.

    I posted it a while back, but I think I’m still in the RC penalty box.

    we will see.

  4. Tom R
    Posted Dec 7, 2007 at 12:58 PM | Permalink

    Gavin’s first sentence: “Many people hold the mistaken belief that reconstructions of past climate are the sole evidence for current and future climate change.”

    I’ve been reading the discussions on CA for a couple of years and I don’t recall any prominent AGW skeptic ever making that seertion. Any idea who he might be referring to?

  5. Larry
    Posted Dec 7, 2007 at 1:01 PM | Permalink

    4, classic strawman.

  6. Tom R
    Posted Dec 7, 2007 at 1:07 PM | Permalink

    Typo in #4. “seertion” = assertion

  7. henry
    Posted Dec 7, 2007 at 1:19 PM | Permalink

    From RC:

    “How to you calibrate low-resolution data? That is still an open question. – gavin]

    Refresh my memory – were the BCP’s considered a low res or high res data?

  8. henry
    Posted Dec 7, 2007 at 1:39 PM | Permalink

    More questions – just how many other studies were based on this “questionable data”, and were they discussed in length here and on RC?

    And does Gavin recommend that the studies be removed from the spagetti chart? I wonder what that chart will look like after that (can’t use these studies, can’t use BCP, etc).

    Were they mentioned in Mann07?

  9. Cliff Huston
    Posted Dec 7, 2007 at 2:20 PM | Permalink

    RealClimate on Moberg:

    http://www.realclimate.org/index.php/archives/2005/02/moberg-et-al-highly-variable-northern-hemisphere-temperatures/

    This paper takes a novel approach to the problem of reconstructing past temperatures from paleoclimate proxy data. A key result is a reconstruction showing more century-scale variability in mean Northern Hemisphere temperatures than is shown in previous reconstructions. This result will undoubtedly lead to much discussion and further debate over the validity of previous work. The result, though, does not fundamentally change one of the most discussed aspected of that previous work: temperatures since 1990 still appear to be the warmest in the last 2000 years.

    These results are bound to stir up interest beyond the scientific community, since the “hockey stick” shape of previous reconstructions has become so totemic (although just about everyone agrees that there is no need for this “totemising” ). We hope that press reports about this paper that mention the increased variability will also emphasize the other key result: that there is “no evidence for any earlier periods in the last millennium with warmer conditions than the post-1990 period – in agreement with previous similar studies (1-4,7)” where (1)is MBH98, (2) is MBH99, (7) is Mann and Jones ’03. The “News” article in Nature explicitly rejects the idea that this means we’re not causing the current warming. And it quotes statistician Hans von Storch (who has been quite critical of the earlier work): “it does not weaken in any way the hypothesis that recent observed warming is a result mainly of human activity”.

    There are a couple of technical concerns with the paper that are worth discussing, and which the compressed space of the Nature publication didn’t leave the authors space to address fully.

    First, its not too clear that the use of wavelets has added much to the mix. Moberg et al. use the wavelets to merge the high-frequency data from the tree rings with low-frequency data from the other sources, which have lower temporal resolution. But that means the low-res proxies are doing all the work, and the tree rings are just adding a fringe of noise that your eye reads as sort-of error bars.

    Second, because they have used the wavelets, they end up with a non-dimensional signal which has to be normalised against the instrumental record from 1859 to 1979.

    http://www.realclimate.org/index.php/archives/2005/02/dummies-guide-to-the-latest-hockey-stick-controversy/

    Firstly, there are more and better quality proxy data available. There are new methodologies such as described in Rutherford et al (2005) or Moberg et al (2005) that address recognised problems with incomplete data series and the challenge of incorporating lower resolution data into the mix.

    http://www.realclimate.org/index.php/archives/2006/06/national-academies-synthesis-report/

    The basic conclusion of Mann et al. (1998, 1999) was that the late 20th century warmth in the Northern Hemisphere was unprecedented during at least the last 1,000 years. This conclusion has subsequently been supported by an array of evidence that includes the additional large-scale surface temperature reconstructions and documentation of the spatial coherence of recent warming described above (Cook et al. 2004, Moberg et al. 2005, Rutherford et al. 2005, D’Arrigo et al. 2006, Osborn and Briffa 2006, Wahl and Ammann in press), and also the pronounced changes in a variety of local proxy indicators described in previous chapters (e.g., Thompson et al. in press). Based on the analyses presented in the original papers by Mann et al. and this newer supporting evidence, the committee finds it plausible that the Northern Hemisphere was warmer during the last few decades of the 20th century than during any comparable period over the preceding millennium.

    http://www.realclimate.org/index.php/archives/2007/01/stalagmites/

    Given the complexity of the signal transfer from the surface to the cave, the only approach is to: (1) work with stalagmites that were actively growing when sampled (so we know the precise age of the top of the archive, and that they were deposited over the period of instrumental rainfall and temperature data), (2) that we use stalagmites which have annual growth rings (in the same manner as tree rings, many stalagmites have annual rings too) so that a precise chronology can be obtained, and then (3) to analyse whichever proxy we are interested in at highest resolution possible to be able to calibrate that proxy against instrumental climate records over the period they exist.

    Some caveats are now needed. Firstly, all three points listed above have to be fulfilled – any two of the three just won’t give the precision in terms of chronology or climate calibration necessary to inform the past climate variability debate (a problem with the Norwegian record that featured in Moberg et al is that it failed all three tests). Secondly, depending on the local site, some stalagmites just won’t record high frequency (e.g. annual) climate variability – that signal could be lost if waters are mixed in with a large reservoir of ground water. But they may be excellent at recording the low frequency (decadal to centennial) climate signal, something that proxies such as tree rings have more of a struggle to do. Thirdly, it is quite possible that stalagmites will have a seasonally biased climate signal. For example, if the cave climate varies seasonally such that stalagmite deposition only occurs for part of the year, or if the rainfall only comes during the wet season, then it can only record that season’s conditions.

    http://www.realclimate.org/index.php/archives/2007/11/les-chevaliers-de-lordre-de-la-terre-plate-part-i-allgre-and-courtillot/

    There is also a bit of nattering about Moberg’s take on the Hockey stick, the supposed considerable warmth of the Medieval Warm Period, and some supposed millennial solar variability which supposedly accounts for why the present warming sort of looks like Moberg’s take on the Medieval Warm. Even leaving aside evidence that Moberg’s method exaggerates variability (see Mann, Rutherford, Wahl and Ammann 2005, available here ), the “blame the Sun” mantra falls apart because neither the Sun nor cosmic rays have been exhibiting any trend that could conceivably account for the recent warming, as we have discussed in many places on RealClimate (most recently here ).

    Cliff

  10. Larry
    Posted Dec 7, 2007 at 2:35 PM | Permalink

    9,

    There is also a bit of nattering about Moberg’s take on the Hockey stick, the supposed considerable warmth of the Medieval Warm Period, and some supposed millennial solar variability which supposedly accounts for why the present warming sort of looks like Moberg’s take on the Medieval Warm.

    Suppose he like sneering pejoratives?

  11. Michael Jankowski
    Posted Dec 7, 2007 at 2:57 PM | Permalink

    Gavin’s first sentence: “Many people hold the mistaken belief that reconstructions of past climate are the sole evidence for current and future climate change.”

    Someone should let Gavin know that people hold the belief that reconstructions of past climate are evidence of PAST climate change.

    The way RC’s statements in post #9 (particularly the first two paragraphs) seem to emphasize the importance of reinforcing the hockey stick, “showing” how warm temps since 1990 are, etc, you would think maybe RC finds that reconstructions of past climate are the most important evidence for current and future climate change. The inclusion of the “News” quote from von Stroch futher emphasizes how important RC seems to link the reconstructions with AGW.

    It’s pretty amusing to see RC initially downplay a connection between the two, yet spend two paragraphs linking the two together.

  12. Francois Ouellette
    Posted Dec 7, 2007 at 3:17 PM | Permalink

    That is, of course, as opposed to the supposed lack of variability of temperatures for the past 2000 years, due to a supposed lack of solar variability, and to a supposed lack of solar influence on climate. And the recent supposed accelerated warming, due to a supposed high climate sensitivity to CO2, all based on a supposed infinitesimal urban heat island effect, and supposed high quality temperature data. Not to mention the supposed skills of climate models.

  13. Mike B
    Posted Dec 7, 2007 at 3:17 PM | Permalink

    Mosher:

    I asked gavin this.

    1. could he give me a list of the 5 proxies that he thought could be used
    2. What would his opinion be of reconstructions that used any one of the remaining 13.

    I posted it a while back, but I think I’m still in the RC penalty box.

    we will see.

    Don’t hold your breath. I’ve been running robustness tests on the “loehle proxies”, and every combination of 11 or more that I’ve tested so far shows MWP > CWP.

    I’m not an expert on all the proxies available, but from what I’ve seen so far, a hockey stick is very difficult to create. Any sensible sampling and weighting of worldwide temperature proxies appears to show MWP>=CWP.

  14. Sam Urbinto
    Posted Dec 7, 2007 at 3:21 PM | Permalink

    Yes, Francois, supposedly.

  15. Posted Dec 7, 2007 at 3:21 PM | Permalink

    In some cases, RC non-linking to climateaudit is mere pettiness, but, in this particular case, they cite information on Loehle that is only available at climateaudit – for example, the exact data citations are provided in a CA post here and not in the original article.

    We need Granger causality test. CA post is useful in forecasting next RC post :)

  16. Jim Clarke
    Posted Dec 7, 2007 at 3:22 PM | Permalink

    Re #9:

    Thanks for digging up all of those comments, Cliff. It seems to me that RC is more concerned with protecting the notion that the current warm spell is unprecidented and humans are to blame, than getting the most accurate reproduction of historical climate. In other words, they seem more focused on an agenda than on science. (Who would have thought?)

    They are very quick to point out that climate reconstructions showing more historic variability do not “…weaken in any way the hypothesis that recent observed warming is a result mainly of human activity.” This is true if one is willing to admit that those reconstructions resembling the handle of a hockey stick do not strengthen the hypothesis that recent warming is the result of mainly human activities. You can not have it both ways.

  17. Larry
    Posted Dec 7, 2007 at 3:28 PM | Permalink

    16, I’m seeing a pattern emerging. They will say [fill in the blank] doesn’t matter when cornered, but will toil endlessly to buttress their original assertion regarding [fill in the blank]. Same for surface temperature vis-a-vis ocean temperatures, same for the hottest temperature of the 20th century. I don’t think this is how scientists are supposed to behave.

  18. steve mosher
    Posted Dec 7, 2007 at 3:36 PM | Permalink

    RE 4. gavin hasnt met a strawman argument that he wouldn’t take a roll in the hay with.

  19. Patrick M.
    Posted Dec 7, 2007 at 3:47 PM | Permalink

    I’m interested in what CA thinks of this comment at RC:

    “This one actually sounds like you could use the old Extended Kalman Filter to assimilate the various series; the individual natural or artificial smoothings peculiar to each series being the nonlinear parameters that the EKF would identify. The point of that is then you could have a single probability model with which all the individual series treatments were consistent.

    The reason the EKF could be expected to work well is that the proxy series appear all to have at most weakly nonlinear processing that needs to be “undone”.

    I don’t know the paleoclimate reconstruction literature enough to know if this has already been tried. It would be an old idea to meteorologists though.

    [Response: Francis Zwiers and a student of his have been looking at this, the tricky part is finding the right model for the temporal dependence. Mark Cane’s group at Lamont Doherty/Columbia has looked at this as well, though the primary applications have involved sparse early historical data rather than proxy data, see e.g. here and here. -mike]“

  20. Posted Dec 7, 2007 at 3:48 PM | Permalink

    Here are valid CIs for Loehle’s unweighted average global temperature series, using the method I described at comment #11 of the 11/21 thread #2405:

    (I already posted this yesterday at #278 of that thread, but being at the end of an old thread it somewhat fell through the cracks.) The exact standard errors vary with the identity of the proxies that are included at any point in time, but generally are around 0.16 dC. Detailed graphs of the individual series etc are in a (very preliminary) note at http://www.econ.ohio-state.edu/jhm/AGW/Loehle/LoehleGraphs.doc.

    The variances of the 18 series differ considerably. Two of them, #3 Cronin and #10 deMenocal, have such high variances that they are actually detrimental to the variance of the unweighted average. Two others, #6 Korhola and #13 Viao, have very low variances about the mean and so are very informative. (These numbers correspond to the data series posted by Steve on CA.

    Because of the unequal variances, Weighted Least Squares (WLS) estimates that weight each series in inverse proportion to its variance are more efficient. The WLS standard errors are generally around 0.10 dC, a considerable improvement over the unweighted Ordinary Least Squares (OLS) estimates above. The WLS estimates with a 95% CI are plotted below:

    If, as Gavin reports, the Farmer series used by Craig was not really temperature but raw Mg/Ca ratios, the calculations could easily be redone. Likewise if he was off by 50 years on some of them because of the C-14 convention that 1950 is the year 0 BP.

  21. Bob KC
    Posted Dec 7, 2007 at 3:50 PM | Permalink

    I enjoyed this recent slip of the pen from Gavin:

    …And in a decade! The statement was/is/remains ridiculous – and it has nothing to do with my lack of an open mind. – gavin]

  22. Bob Meyer
    Posted Dec 7, 2007 at 4:18 PM | Permalink

    Re:15 UC said:

    “CA post is useful in forecasting next RC post”

    Perhaps it is not a forecast but actually an example of phase delayed teleconnection.

  23. Craig Loehle
    Posted Dec 7, 2007 at 4:20 PM | Permalink

    I have gotten as far as responding to the point that I used the wrong data column for the Farmer data: mea culpa. Fortunately, since it is a linear transform to temperature and both proxy and temp have a similar range of values, the corrected plot is almost identical to the naked eye to the one in my paper. This error was found by Eric Swanson. Thanks Eric! (bet you don’t hear that very often!)

  24. Chris
    Posted Dec 7, 2007 at 4:22 PM | Permalink

    Gavin was right, there was never much to discuss in this paper to begin with. Anyone here would be much wiser to go with the National Academies or IPCC on the subject. AGW skeptics will only be taken seriously publsihing for obsure journals like E & E anyway, but at least these “competition of the blogs” make good for entertainment. We can all complain about bias, but it works both ways: McIntrye likes to go on one-man kamikaze missions on any reconstruction showing a “hockey stick” but didn’t seem to care to double-check this one for errors and we all had to wait for RC. Above comments are really quite bizarre.

    #21- where is the slip? Explain ho the sun factor is going to act like the comments at RC implied?

    #22- Perhaps Larry should have replied to the thread at RC. What doesn’t he like? In almost any skeptic argument (they’re all the same and predictable- sun, water vapor, CO2 lag, 1940-70 cooling, MWP, CO2 is small part of the atmosphere, ad nauseum- just watch Durkhim’s video) the CO2 lag comes up, and it is a terrible counterargument.

  25. steve mosher
    Posted Dec 7, 2007 at 4:28 PM | Permalink

    Hey, he answered my question!

    Interesting criteria. But he let my comment through. Good for Gavin!

  26. Larry
    Posted Dec 7, 2007 at 4:29 PM | Permalink

    A veritable parade of strawmen…

  27. Pat Keating
    Posted Dec 7, 2007 at 4:32 PM | Permalink

    20 Hu
    Good work!

  28. Bob KC
    Posted Dec 7, 2007 at 4:45 PM | Permalink

    Re#25

    Well, I assumed he didn’t mean to agree that he lacked an open mind. Maybe I was wrong.

    I would have worded it something more like “and it has nothing to do with whether or not I lack an open mind”.

  29. MarkW
    Posted Dec 7, 2007 at 5:08 PM | Permalink

    Actually the RC post caused the CA post. It’s just another example of effect preceeding cause. Not at all unusual in post modern climate science.

  30. Craig Loehle
    Posted Dec 7, 2007 at 5:31 PM | Permalink

    RC claims that I did not use proper start dates for Kim, Farmer, and DeMenocal. The archives for these three appeared to be calendar dates. I am looking into it, but if I alter these three to a 1950 0 year, the MWP relation to recent does not change, though small scale squiggles along the plot change.

  31. Larry
    Posted Dec 7, 2007 at 5:35 PM | Permalink

    If that’s the worst they can come up with, I think you’ve survived your trial-by-blog.

  32. Ian Castles
    Posted Dec 7, 2007 at 5:47 PM | Permalink

    Re #25. Our host introduced Loehle 2007 on 14 November with the statement “Thread for discussion of Loehle 2007. I’ll try to comment later but have some other obligations right now.” Steve’s prompt posting of the material sent to him by Craig Loehle was eminently sensible and he was no obligation to “double-check” the paper before opening it up for discussion by others. Your comment that he “didn’t seem to care to double-check this [paper] for errors and we all had to wait for RC” is an outrageous misrepresentation.

  33. Alan D. McIntire
    Posted Dec 7, 2007 at 5:52 PM | Permalink

    Re #22- David Holland’s argument appeared to be lethal. There must have been a lot of heat
    going into the melting of those glaciers prior to any temperature rise. Most of the additional
    heat would have already gone into the system well before the CO2 started rising 800 years later.

  34. Posted Dec 7, 2007 at 6:07 PM | Permalink

    Steve Mosher writes @ #26,

    Hey, he answered my question!

    Interesting criteria. But he let my comment through. Good for Gavin!

    But all he’s doing is listing the 5 that continue past 1970. Many of Craig’s series terminate in 1950. Taking his approximately 30-year rolling mean into account, this means his reconstruction isn’t telling us a lot after 1965 anyway. Gavin is asking too much to expect it to tell us much about late 20th century temperatures. At best, it’s linking the mid and early 20th centuries to the previous 2 millennia. If someone wants to extrapolate it to 2007, they would have to link instrumental data to it for say 1900-1965 and then continue to the present.

    This assumes, of course, one has good instrumental data for the 20th century to this precision. The popular Hadley CRU series rely on questionable stations like Runway 28L of Port Columbus International Airport, just to take the one nearest where I live. This site has undergone considerable urbanization since 1948 when the station opened. Do we have any reason to believe the others are any better, on average?

    It should be some consolation to Gavin that Craig’s MWP, although statistically significant during most of 850-1050, is not terribly warm — only about .4 dC above average using Craig’s unweighted mean, or .25 dC using my weighted mean. The overheated CRU index would probably not exceed the upper CI bands for the MWP if spliced onto Craig’s series, but might easily reach the point estimate.

  35. Chris
    Posted Dec 7, 2007 at 6:36 PM | Permalink

    #38- best they can come up with? Loehle used a screwed up method, with little understanding of proxy-paleoclimatic work, and published in a screwed up journal, and it will be ignored for all practical purposes by serious academic community. Please. As for Moberg, screwing up Farmer and inconsistent concept and series usage are solely on Loehle. There were some I wouldn’t use if I was Moberg (e.g. Nyberg et al) but this doesn’t matter much now with the growing archive, but the criticisms on Loehle can’t just be superimposed on Moberg. For saying “best they can do,” the the best this blog can do is still jump all over a 1999 paper and run missions to make people think everything in the NAS report or IPCC or dozens of other studies is wrong. You should create a mission statement for this site- “we will continue to try to get a MWP no matter what.” Some of the comments above can add and then try to get relevance to the attribution effort for today’s warming. Actually, I’d be a bit more worried if Loehle is right: it would hint at higher climate sensitivty if causes are unmodified. If past fluctuations turned out to be a bit bigger than we suspect, this in no way affects attribution of recent warming to CO2: we know that the sun is not changing, cosmic-rays are not changing, heat is going into the ocean not coming out, enhanced downward infrared flux, stratosphere cooling, and other things that allow attribution with very high confidence. For posters who want “proof,” you are in the wrong field- try math.

    #32- you’re right, it isn’t increasing. The worldwide glacier retreat, increased ocean heat content, sea level rise, TOA radiative imbalance, satellite and ground and radiosonde data is all an illusion. [snip[ Then, we can ignore the rather basic radiative physics behind CO2 because spectrometry and greenhouse basics is not longer important. In fact, in the physics-free world, we can just hope for a hypothetical scenario where the sun is doing some weird thing we don’t know about, or just hope that all our current ways to get a meaningful global temp increase are off, despite consistent and coherent responses from biological activity, ice masses, snow cover, etc. Wishful thinking won’t get you too far, except a quick comment on the blogosphere.

    Also, are people still taking the CO2 lag argument seriously? I do hope that one posters husband understands Milankovitch cycles, and Henry’s law, and feedback processes, and the timescales in the glacial-interglacial cycles.

  36. Chris
    Posted Dec 7, 2007 at 6:44 PM | Permalink

    #39

    There is a big difference in tone between studies that show a MWP and those that don’t here. Just “open up for discussion” studies like Loehle or Scafetta and West to lay-readers who aren’t experts at picking up these subtle errors like “1950 is BP”, but go on rants for dozens of posts and publish articles in the peer-reviewed literature and run attack missions on policy for those like Mann et al? Everytime I am posting on forums, the only reason people ever link me to here is to convince me that there was a MWP and all the hockey stick graphs are bogus.

  37. steve mosher
    Posted Dec 7, 2007 at 6:52 PM | Permalink

    RE 42. Hu. “interesting criteria” was somewhat sarcastic. My fault.

    My sense is now we can go through every paleo paper and cull out the proxies that doent extend beyond
    1970. And next year those that dont extend beyond 1971 etc etc. and in few years gavinology will result
    in the deletion of all BCPs.

    IN fact, what a fun excercise. what happens when we use a 1970 cut off date.. or 1975.. or 1980.

    Why 1970? did gavin peek at the land record and decide that 1970 was a good cut off date.
    Why 1970? why not 1971? 1972? why not jan 7th 1974?

    Sorry, being sarcastic again

  38. Pat Keating
    Posted Dec 7, 2007 at 6:59 PM | Permalink

    43 44
    Chris, why don’t you post some well-considered facts, instead of just ranting? This is a scientific blog, not a Hyde Park soap-box.

  39. John V
    Posted Dec 7, 2007 at 7:05 PM | Permalink

    I think the problem with Loehle’s proxies ending in 1970 is that Loehle2007 makes explicit comparisons between the MWP and the *current* temperature. If his conclusions were restricted to mid-century comparisons, then proxies that end mid-century would not be a problem (with me at least).

  40. Steve Moore
    Posted Dec 7, 2007 at 7:09 PM | Permalink

    The statement was/is/remains ridiculous – and it has nothing to do with my lack of an open mind. – gavin]

    Give the man credit: he’s honest to a fault.

  41. Larry
    Posted Dec 7, 2007 at 7:12 PM | Permalink

    49, so you seem to be suggesting that reconstructed temperatures aren’t real temperatures, if it’s only fair to compare proxies to other proxies.

  42. yorick
    Posted Dec 7, 2007 at 7:23 PM | Permalink

    Chris

    but the criticisms on Loehle can’t just be superimposed on Moberg.

    Why not if he uses the same proxies?

  43. Posted Dec 7, 2007 at 7:49 PM | Permalink

    #50 Larry:
    The numbering is messed up so I’m not sure if your post was meant for me.

    so you seem to be suggesting that reconstructed temperatures aren’t real temperatures, if it’s only fair to compare proxies to other proxies.

    I don’t understand your point. Loehle2007 used proxy measurements (only) to conclude that MWP was warmer than *current* warming. Bender and others have made it very clear that the instrumental record can not be used in a comparison with proxies, for numerous reasons.

  44. Steve McIntyre
    Posted Dec 7, 2007 at 8:49 PM | Permalink

    One of my earliest posts was “Bring the Proxies Up to Date” and this summer we disproved Mann’s hypothesis that it was too “expensive” and difficult to update tree ring proxies.

    Having said that, Gavin’s point about the end points of the low-freq proxies has considerable validity. Here are the end points of the various series that come mode modern than 1970: Shihua – 1985; Yang – 1990; Chesapeake 1995; Ge phenology 1995; GRIP borehole 1996; holmgren 1996. The Loehle version of Kim et al and Farmer et al are allocated dates that are too recent.

    So how does this criticism apply to the closely related Moberg low=frequency network. Proxies with values in 1980 are: GRIP borehole (match); Chesapeake (match); Shihua=Beijing stalagmite (match); Yang China (match); and the very questionable Arabian Sea G Bulloides series.

    So Loehle has two low-freq series not used in Moberg: Ge and Holmgren, while Moberg has one low-freq series not used in Loehle: the uncalibrated G Bulloies series.

    What’s sauce for the goose is sauce for the gander.

  45. Steve McIntyre
    Posted Dec 7, 2007 at 8:50 PM | Permalink

    No CO2 lag discussions on this thread please.

  46. Phil.
    Posted Dec 7, 2007 at 9:01 PM | Permalink

    Re#44
    “What’s sauce for the goose is sauce for the gander.”

    Only if both goose and gander said:
    “Even keeping in mind that Figure 1 shows 30-year running means, it would indeed seem to show the MWP to be warmer than the late 20th century.”

  47. Ellis
    Posted Dec 7, 2007 at 9:03 PM | Permalink

    Jeez Steve, you make one comment on RC and you shut the whole site down. What did you do?

  48. Chris
    Posted Dec 7, 2007 at 9:11 PM | Permalink

    #44 McIntrye

    the uncomfortable truth is you cannot make long, well-calibrated instrumental records appear at the sites where you decide to collect an ice core or lake core or tree ring, and the long instrumental records are almost never collected in places suitable for ice-coring or lake-coring or tree-ring coring, so some long-distance or otherwise relations must be sought.

    This whole thing of siding with realclimate or this blog would be a lot better if either site would post some of the problems with “AGW and no-AGW.” That is, if RC put more emphasis on the problems with pro-AGW articles that aren’t that great (like being more critical of Gore’s movie). Similarily, instead of this site complaining about how much paleoclimate sucks, it could also mention the strong evidence for AGW that crops up in the literature, and be more critical of papers like Loehle. Imagine a blog that REALLY posts the evidence, as well as the problems with AGW. Maybe it’s a dream.

  49. Posted Dec 7, 2007 at 9:18 PM | Permalink

    Gavin got the data file from Eric Swanson who got it from Craig Loehle. You might want to alter the first sentence. See RC comment 13 for details.

    Since the current global surface temperature is about 0.5-0.6 C above 1950 eyeballing Hugh McCullogh’s graphs puts the current value well above the peak of the European Warm Period ~1000 AD

  50. Lance Hilpert
    Posted Dec 7, 2007 at 9:22 PM | Permalink

    #50

    Sigh. Another rant . . . .

  51. Chris
    Posted Dec 7, 2007 at 9:26 PM | Permalink

    Sorry, I missed 42. Not that the proxies are the same or not the same. I said in my earlier post- Screwing up the dating, inconsistent treatment of concept and series are Loehle’s alone, and the screwing up of Farmer and DeMenocal and other studies are Loehle’s alone. I am astonished that #30 Loehle gets off as easy as “I screwed up the method, but the conclusion is all that matters.” Sounds kind of like another paper I hear a lot about on this site ;-)

  52. Chris
    Posted Dec 7, 2007 at 9:33 PM | Permalink

    #52

    so you don’t like objectivity? Or maybe it is a “rant” as opposed to other posts simply because I accept AGW? I don’t understand the problen here, I simply asked if McIntrye would blog on some of the evidence for AGW, and placed the same criteria on RC to not be so kind with the article on Gore’s movie, or other “pro-AGW yet erroneous” articles. For example, the 1934 article. RC could have made a bigger deal about the screw up, but McIntrye could have kept the actual influence on global temp a but more in perspective. IS that too much to ask? I realize the blogosphere has to be dramatic and everyone needs to take sides, something that isn’t so obvious in the peer-reviewed literature, but c’mon

  53. M. Jeff
    Posted Dec 7, 2007 at 9:38 PM | Permalink

    re: #50, Chris, December 7th, 2007 at 9:11 pm and #24, Chris, December 7th, 2007 at 4:22 pm

    My impression after reading these posts is that Chris is not familiar with CA.

    And, I second the opinion expressed by Ian Castles, December 7th, 2007 at 5:47 pm, (#25 in the quote below is now #24).

    Re #25. Our host introduced Loehle 2007 on 14 November with the statement “Thread for discussion of Loehle 2007. I’ll try to comment later but have some other obligations right now.” Steve’s prompt posting of the material sent to him by Craig Loehle was eminently sensible and he was no obligation to “double-check” the paper before opening it up for discussion by others. Your comment that he “didn’t seem to care to double-check this [paper] for errors and we all had to wait for RC” is an outrageous misrepresentation.

  54. Chris
    Posted Dec 7, 2007 at 9:48 PM | Permalink

    #57 “not familiar with CA”

    Please see all the “Categories” here:

    * AIT, * Archiving
    o Nature
    o Science
    * Data
    * Disclosure and Diligence
    * FOIA
    * General
    * Holocene Optimum
    * Hurricane
    * IPCC
    * MBH98
    o Replication
    o Source Code
    o Spot the Hockey Stick!
    o Wahl and Ammann
    * Modeling
    * News and Commentary
    o Barton Committee
    o NAS Panel
    * Other Multiproxy Studies
    o Briffa
    o Crowley
    o Esper et al 2002
    o Hansen
    o Hegerl 2006
    o Jones & Mann 2003
    o Jones et al 1998
    o Juckes et al 2006
    o Loehle 2007
    o Mann et al 2007
    o Moberg [2005]
    * Proxies
    o Antarctica
    o bristlecones
    o Geological
    o Jacoby
    o Mann PC1
    o Medieval
    o Noamer Treeline
    o Ocean sediment
    o Post-1980 Proxies
    o Solar
    o Thompson
    * Satellite and gridcell
    * Scripts
    * Sea Level Rise
    * Statistics
    o principal components
    o Spurious
    * Surface Record
    o Jones et al 1990
    o NASA (Hansen)
    o UHI
    * TGGWS
    * Uncategorized
    * Unthreaded

    How many of them can I click on and not find a bunch of complaining about the hockey stick? Maybe I’ll find a post of radiative physics and the infrared absorption bands of CO2? Help me out

  55. M. Jeff
    Posted Dec 7, 2007 at 9:57 PM | Permalink

    re: #58, Chris, December 7th, 2007 at 9:48 pm.

    Just the fact that you did not seem to be familiar with, “Thread for discussion of Loehle 2007. I’ll try to comment later but have some other obligations right now.”, is enough evidence for me. I’m relatively new to this blog and somewhat aged, but I recalled that Steve McIntyre had made that statement.

  56. Mike Davis
    Posted Dec 7, 2007 at 10:01 PM | Permalink

    Cris:
    Please stop by RC and ask Gavin et.al to correct current temp records back to the seventys if you are concerned about global warming

  57. Steve McIntyre
    Posted Dec 7, 2007 at 10:32 PM | Permalink

    I said that the criticisms of Loehle alsop apply to the closely-related Moberg reconstruction.

    In #44, Chris said:

    the uncomfortable truth is you cannot make long, well-calibrated instrumental records appear at the sites where you decide to collect an ice core or lake core or tree ring, and the long instrumental records are almost never collected in places suitable for ice-coring or lake-coring or tree-ring coring, so some long-distance or otherwise relations must be sought.

    Be that as it may, that does not justify Moberg relative to Loehle (or vice versa.) Phil, you say that Loehle is blameworthy because he drew conclusions about the MWP vis a vis the modern warm period. Moberg drew opposite conclusions. But that’s beside the point. The issue is that Moberg’s proxies low-freq proxies overlap with Loehle’s. So that my point that the Loehle critique also applies to Moberg still remains.

    Chris, I think that I’ve been pretty consistent in saying that Loehle and Moberg are pretty much peas in a pod and that I don’t see how you can objectively prefer one to another. Yes, there are some errors in Loehle, but there are some errors in Moberg as well. Moberg inadvertently used one bristlecone series twice in two different versions. It also looks to me like he got something wrong in the Lauritzen series which ens in the 19th century in the original article and in the 1930s in Moberg.

    To a considerable extent, I’ve been interested in the critiques of Loehle – originally JEG’s and now realclimate’s. I’m not arguing that their criticisms are invalid – as I noted, Gavin can be a good “climate auditor” when he turns his mind to it. My beef is their failure to be consistent and to apply similar diligence to the other studies. Imagine the reaction if Loehle had mislocated proxies as grotesquely as Mann did, and then refused to correct the locations.

    You suggest that I should cover other lines of “strong evidence for AGW that crops up in the literature”. Look, I’m just one person and there’s only so much that I can do. As it is I’m covering a lot of ground. I’ve done some posts on modeling and even a few on water vapor NIR, but it’s impossible for me to cover the topic in the detail that I do things without restricting myself to that topic and leaving other topics unfinished.. I’ve been looking for some time for an article that clearly derives 2.5 deg C from doubled CO2 – one which does not merely report on a GCM run, but which describes in engineering-level detail the key parameterizations for the major feedbacks. So far I’ve received some citations to articles from the 1950s, but I’d like something that represents modern thinking. If you can identify such an article for me, I’ll try to discuss it some time in the next few months.

  58. Dave Dardinger
    Posted Dec 7, 2007 at 11:10 PM | Permalink

    I’d like to know just what the strong evidence for AGW is that Chris claims. I suspect he’s talking the usual suspects, but before digging in, I’d like him to make particular claims. BTW, just who is Chris? He makes his crits sound like he’s in the field, but since he doesn’t actually present specific complaints beyond what has already been stated here by JEG and even Bender, it might be a pose.

  59. tetris
    Posted Dec 7, 2007 at 11:41 PM | Permalink

    Re:49 and 57
    Eli Rabett and SteveM

    Proxies here and proxies there; MWP vs. CWP, etc., etc.. It’s all getting to be quite academic, navel gazing, and quite frankly truly boring.

    Reality check: based on best available data for the year and a fact recently [very reluctantly] acknowledged by NOAA, and [very red faced] by the British Met Office and HADCRU [who pls note the date: on Jan 4, 2007, stated that "2007 is going to be the warmest year on modern record"] in actual fact 2007 is in the process of going into the history books as the coldest year globally since 1995… The R squared value between CO2 values and temperature fluctuations for North America for the period 1895-2005 is 0.29 or therabouts. Which begs the question: what in all hell are we talking about.

    We have ample evidence other than tree cores or sea bed deposits or what have you, to tell us that there were periods over the past 2000 years in which temperatures were at least as warm if not warmer than we are seeing today. There is indisputable evidence other than thermometers and the like that clearly correlates these temperature fluctuations with the ups and downs in terms of economic growth and societal development [warmer=better; colder=worse, it's that simple].

    We knew that RC was going to have a go at the Loehle 2007 study, that was easy to predict.
    That they took quite this long possibly tells us that the Hockey Team didn’t like its implications. Not much more.
    That RC committed the sin of plagiarism as outlined above is only a marker of how low this “discussion” has sunk.

  60. Jon
    Posted Dec 8, 2007 at 12:23 AM | Permalink

    Another approach, used implicitly in climate field reconstruction methods (like RegEM for instance), is to use current instrumental records to assess the relevance of any particular point, region or time period to the desired target.

    I can’t quite grasp what Gavin is saying here. “region or time period” -> “Desired Target” Huh? Can someone explain?

  61. Peter
    Posted Dec 8, 2007 at 1:59 AM | Permalink

    If you put it all together, do you not arrive at the following: that using the proxy record alone, MWP was about at the same levels as modern warming for the period the proxies cover. This is assuming the proxies really do measure temperature. So warming and cooling can both happen without any assistance from CO2. You are still left however with the question, whether there is anything remarkable about the last 10 or 20 years compared to the 20c record

    Then, if you look at McKittrick’s stuff about the measured temp record, the divergence between ground temps and satellite measurements, the divergence between US and ROW ground temps, you come inevitably to the conclusion that the recent temperature record is not remarkable in 100 year terms. Not only that, but it seems that the last few years show that stable or falling temps are compatible with rising CO2 levels.

    Surely, there is just nothing left after you this? It simply is not possible to argue for impending doom or even AGW and take account of this evidence? You are left with the null hypothesis, climate fluctuations about some mean over periods of decades or centuries, due to causes not yet established.

  62. bender
    Posted Dec 8, 2007 at 2:05 AM | Permalink

    The arguments for either Loehle 2007 or for Moberg et al 2005 are highly specious. Special pleading on either side (a logical fallacy) is wholly unjusitified. The reality is that these are only two flavors of millions that could be drawn from this set of proxies. This is the lesson taught to us by Burger and Cubash. Nobody but Steve M (and the CI gang: UC and Jean S, and now Hu McCullough) seems to understand this. If you were to do an honest-to-goodness spaghetti-o-gram that included the kinds of uncertainties that a young and honest policy wonk like Susann is asking for, you will simply not find a difference between MWP & CWP. Who wants to bet $100 in the CA tip jar? Chris? I’ll give you 10:1 odds.

    Gavin Smidt will try to tell you this fact doesn’t matter. That is not my opinion. What is at stake here is use of the term “unprecedented” – which Hansesn, Schmidt and the entire RC crowd love to employ. In my opinion use of the term is not justified. Not when it comes to these proxies.

  63. Philip_B
    Posted Dec 8, 2007 at 2:06 AM | Permalink

    Jon, I assume this is a reference to the practice of using (the theory of) teleconnection patterns to justify data mining (data fishing) for climate correlations. Here is a CA thread on RegEm.

  64. bender
    Posted Dec 8, 2007 at 2:27 AM | Permalink

    #54
    Chris, step up your game. When reading CA, look past the noise and look for the signal. CA is very noisy, yes. But there is a bright and meaningful signal at the core of it. The signal is this: there are problems in climate science. Problems of transparency and accountability. Problems of scientists stepping into advocacy roles, and policy people posing as scientists. Problems with statistics on all sides. Do not try to judge CA as a whole, or you will be misled. CA is not a collective voice. It is an assemblage of rogue individual voices who are fed up with bad scientific practices, and irrational policies. Those used to collegiality, like yourself, will find CA exceptionally noisy. Recalibrate your filters. Teleconnect with the signal. The signal says: change is needed.

    Then go back and read RC. See how they scramble now to embrace statistics? Or at minimum to pay lip service to it? Why? Because there are deep problems with the way climatologists view their object of study, and they know it. Thanks to Wegman, they can not hide from it. The quiet ones know it too. The climatologists that you will never, ever hear on RC. The ones who refuse to step into roles of advocacy. The silent minority that grows daily.

  65. JamesG
    Posted Dec 8, 2007 at 5:19 AM | Permalink

    The thing that most struck me about the individual temperature series used in Loehle’s reconstruction is that none of them looked remotely like each other. Doesn’t that confirm that any warm or cold spots were likely regional?

  66. welikerocks
    Posted Dec 8, 2007 at 6:54 AM | Permalink

    re: 61 and 62, and 64 Exactly.

    “This is assuming the proxies really do measure temperature.”

    Yeah, there you go. They don’t measure temperature, they gave you and idea of what the temperature might have been like. Then to go argue or alarm, or make statements like Eli in #49 here which is really about fractions of an idea of temp between the MWP and CWP as if they do measure temp (with a margin for error that may exceed those fractions and over large time scales) ; this is simply mind boggling to me. (And I only brought up the lag topic on RC(sorry!) because it illustrated the same type of foggy bottom stuff. Not to disprove anything once and for all with that example-heck there’s “other evidences” I can draw from for that kind of an argument ;) )

  67. Steve McIntyre
    Posted Dec 8, 2007 at 7:25 AM | Permalink

    #77.

    The thing that most struck me about the individual temperature series used in Loehle’s reconstruction is that none of them looked remotely like each other. Doesn’t that confirm that any warm or cold spots were likely regional?

    This is a very important point and one that applies to the other studies as well.

    Do these plots show that the warmth/cold was regional or that the proxies aren’t necessarily “proxies” for temperature, but might be reflecting something else. I’ve observed a spaghetti inconsistency between different reconstructions in the Urals. But I don’t think that Yamal was regionally cold in the MWP while the Polar Urals about 60 miles away were warm.

    It is the lack of a consistent “signal” that really causes the dispute over methodology. If you had a consistent signal, you’d get pretty much the same answer no matter what multivariate methodology you used. Because there is no consistent signal, changes in weights yield quite different results. The Team gets one set of answers by picking the same proxies over and over and applying slightly different methods to them.

  68. Steve McIntyre
    Posted Dec 8, 2007 at 7:35 AM | Permalink

    I know that people want to use every thread to discuss “big picture” matters, but please resist the temptation. It’s not because the big picture isn’t important; it is. It’s just that I also think that there’s a role for discussing specific details in a technical way and that there’s a role for this. So if you want to editorialize on AGW or IPCC, please find a relevant thread or Unthreaded.

  69. Jim Clarke
    Posted Dec 8, 2007 at 7:43 AM | Permalink

    James G,

    It would be strange indeed if all of the proxies from the different parts of the globe looked identical. Consider that the warming of the last 100 years has been regional and mainly concentrated in the high northern latitudes. Antartica has been generally cooling and most areas in the tropics and Southern Hemisphere have no, or barely discernable trends over the time period. Even in the Northern Hemisphere, there are many instrument records that indicate cooling over the last century. The Idso’s have had a good time posting a different station record ever week for many years now. In total, however, the evidence is very strong that the ‘global temperature’ has been warming.

    In both the modern era and in the paleoclimate studies, the global temperature is determined by combining all of the data to get the global trend. Regional climates can and do vary significantly.

  70. Posted Dec 8, 2007 at 7:53 AM | Permalink

    #67

    It is the lack of a consistent “signal” that really causes the dispute over methodology.

    Yes. For example, in #20 figures, zero-line is outside the confidence limits some 5 % of the time ;)

    If you had a consistent signal, you’d get pretty much the same answer no matter what multivariate methodology you used. Because there is no consistent signal, changes in weights yield quite different results.

    Yep. For example, calibration lines approach each other when SNR gets higher ( http://www.geocities.com/uc_edit/calibration.jpg ).
    And MBH99 results will look very different if you skip the variance matching and do not apply the S=I assumption ( http://www.climateaudit.org/?p=2445 ) .

  71. Boris
    Posted Dec 8, 2007 at 7:54 AM | Permalink

    I like the gratuitous plagiarism charge.

  72. Posted Dec 8, 2007 at 8:05 AM | Permalink

    “Eli Rabett”, who I gather is really Joshua B. Halpern of the Howard University Chemistry Dept (http://www.coas.howard.edu/prem/Personnel/Faculty/Halpern.html) writes in #49,

    Since the current global surface temperature is about 0.5-0.6 C above 1950 eyeballing Hugh McCullogh’s graphs puts the current value well above the peak of the European Warm Period ~1000 AD

    Craig’s graph is not restricted to Europe. In fact, even though he was just trying to assemble every peer reviewed T-calibrated series he could find, it has a lot of global distribution, including coverage in N. Am and Asia — See Hans Erren’s graph posted on an earlier thread in this category. I suspect that in Europe and the N. Atlantic the MWP must have been considerably stronger than just 0.4 or 0.25 dC, in order to permit Viking settlement in Greenland.

    The current global surface temperature that you refer to is likely the Hadley CRU series. The CRU station list was a closely kept secret until CA regular Willis Eschenback pried it out of Jones with an FOI action — see CA threads dated 10/1 and 10/3/07.

    So what’s the CRU station closest to Howard University? Just guessing, I’d say Washington National Airport, given CRU’s affinity for urban airports (7 out of 9 CRU stations in Ohio). When you GoogleEarth its coordinates, how many planes landing or taking off can you count in the same picture? Is this station measuring climate change or air traffic and urbanization?

    Now that the CRU list is available, I’m sure there will be extensive auditing of it in the future, but that’s for some other thread.

    Craig in fact has no coverage at all in S. Am, and nothing in central Asia except for 2 series that supposedly cover all of China. I would love to see the coverage improved with Lonnie Thompson’s ice core series from the Andes, Himalayas, and Alaska, if he would ever get around to calibrating them to temperature and publishing and archiving the results.

    In case Eli/Josh and Chris missed it, the graph identified by Al Gore as “Dr. Thompson’s Thermometer” in AIT was just the MBH99 hockey stick spliced together with the CRU instrumental series in such a way as to conceal the separate identify of the two series and exaggerate the recent warming. The House Committee on Energy and Commerce Committee fell for Gore’s claim that this was based on Thompson’s ice cores, and Thompson has apparently done nothing to publicly correct the record.

    (PS, Steve, how does one upload a GIF to a comment? I posted the graphs in #20 by uploading them to my website and then linking their URLs, but I can only do that from my office, and not everyone has a website.)

    Steve: you can upload pictures to public areas e.g. esnips or picasa .

  73. welikerocks
    Posted Dec 8, 2007 at 8:12 AM | Permalink

    #72 Hu, you can use a place like http://www.tinypic.com to upload and host your graphics for free, and it will also give you all the code to copy and paste where needed after you do the upload. It’s really easy.

  74. steve mosher
    Posted Dec 8, 2007 at 8:14 AM | Permalink

    re 72. use imageshack.us

  75. steve mosher
    Posted Dec 8, 2007 at 8:18 AM | Permalink

    boris you will note that I asked gavin very nicely to cite his source and he did.

    Steve: Watch the pea under the thimble. He didn’t say that he didn’t consult CA, only that he had an alternative source for the numbering which he happily provided. However he also provided exact data citations for Loehle’s versions and the only place in which Loehle gave exact digital data citations was at CA. It’s possible that Gavin ignored the data citations provided by Loehle here, foraged around the internet and located digital sources for Loehle’s versions and then went to the trouble of verifying that these digital sources matched Loehle’s. Do you believe that he did this? It’s possible, but it would be more logical for him to use Loehle’s actual data citations provided here and that’s what I think that he did. If Gavin says explicitly that he did not consult the CA posts, then I would accept his explicit statement, but he’s not said that.

  76. Posted Dec 8, 2007 at 8:54 AM | Permalink

    chris, #%4, 9:48pm.

    How many of them can I click on and not find a bunch of complaining about the hockey stick?

    Very few of them. You are confusing “complaining” with “dismissiveness.”

  77. Kristen Byrnes
    Posted Dec 8, 2007 at 8:56 AM | Permalink

    The main point that Steve Mc was making in this thread was that the standards used by RC in criticizing Craig Loehle need to be applied to Moberg. For those who usually want to agree with RC and disagree with Steve seem to be avoiding this rather valid point.

  78. RomanM
    Posted Dec 8, 2007 at 9:06 AM | Permalink

    Despite the nonsense in most of his posts, Chris did what appears to be at least one good thing – he provided a link in comment #24 to a book, Surface Temperature Reconstructions for the Last 2,000 Years from the National Research Council. From a superficial reading of several sections, it appears to be a decent source of basic information about the different types of proxies. The book can be read online or a pdf can be downloaded (for free!) by registering.

    Steve: THis report has been discussed at length here – see the NAS Panel category. This panel originated out of our articles; Ross and I appeared before them.

  79. Mike B
    Posted Dec 8, 2007 at 9:57 AM | Permalink

    #62 bender

    The arguments for either Loehle 2007 or for Moberg et al 2005 are highly specious. Special pleading on either side (a logical fallacy) is wholly unjusitified. The reality is that these are only two flavors of millions that could be drawn from this set of proxies. This is the lesson taught to us by Burger and Cubash. Nobody but Steve M (and the CI gang: UC and Jean S, and now Hu McCullough) seems to understand this. If you were to do an honest-to-goodness spaghetti-o-gram that included the kinds of uncertainties that a young and honest policy wonk like Susann is asking for, you will simply not find a difference between MWP & CWP. Who wants to bet $100 in the CA tip jar? Chris? I’ll give you 10:1 odds.

    The “special pleading” bit for Moberg vs Loehle sounds an awful lot like a strawman to me. I’ve commented primarlily on Loehle because the data was more readily available and I was working on my on take on his paper (not Moberg). And the two papers share many of the same series anyway.

    The approach I’ve taken to the analysis is to examine subsets of the proxies. This allows detection of sets of proxies that exert undue influence on the overall combination, on any particular era, or any particular region. It provides for an approach for calculating confidence intervals (bootstrapping, which I’ve mentioned before). It doesn’t seem like this type of analysis is standard part of paleoclimatee studies, although it should be. But as Wegman stated, since there is little contact between the paleos and mainstream statisticians, this isn’t surprising. It also isn’t shameful, or at least it wasn’t at first.

    So Bender, the members of your special little club are not the only ones who understand what the implications of these proxies are, and I can’t
    understand what your purpose is for claiming some secret special knowledge or insight for yourself. Can we please leave the insufferable condescention to other climate websites?

  80. Posted Dec 8, 2007 at 10:01 AM | Permalink

    #51: You’re not really being fair at all. Loehle did not ever say what you claim he has said; rather, he has said that he’s made a mistake and will correct it. He wants more corrections.

    P.S. Why are you claiming that Loehle got a free pass here? Have you read this thread?: http://www.climateaudit.org/?p=2380 The difference is that he wants to correct errors and acknowledges them. I would not expect him to publish the same flawed paper over and over again like someone else we know.

  81. Posted Dec 8, 2007 at 10:10 AM | Permalink

    UC (#70) writes,

    Yes. For example, in #20 figures, zero-line is outside the confidence limits some 5 % of the time

    Good point, if we had no historical suspicion of an MWP or LIA. However, the MWP (according to Wiki in any event) supposedly was c 800-1300, while the LIA was c 16-19th centuries. The fact that Craig’s data shows significant warming during most of c 850-1050 and significant cooling during most of 1450-1650 is therefore not just data mining.

    I would have expected the LIA to have set in earlier, given that Greenland was prospering in the early 13th century, froze out during the 14th century, and was depicted as permanently connected (by sea ice, presumably) to Norway or Russia in early 15th century maps.

  82. Posted Dec 8, 2007 at 10:23 AM | Permalink

    Here’s a color spaghettigram of Craig’s (2007) data, thanks to imageshack.us per
    Steve Mosher’s suggestion:
    [URL=http://img137.imageshack.us/my.php?image=pastatx5.gif][IMG]http://img137.imageshack.us/img137/3295/pastatx5.th.gif[/IMG][/URL]
    (I think this will give a thumbnail that can be expanded into a
    legible image).

  83. Posted Dec 8, 2007 at 10:29 AM | Permalink

    Try, try again:

    Notice that a few of the series, after Craig’s approximately 30 year rolling average, appear as broken step functions.

  84. steve mosher
    Posted Dec 8, 2007 at 10:36 AM | Permalink

    Hu dont use the thumbnail option.

  85. Bruce
    Posted Dec 8, 2007 at 10:59 AM | Permalink

    Anyone notice that Nov 2007 Southern Hemisphere HADSST2 is down to .061 above the 1960-1991 mean?

    It hasn’t been that low since 1992.

    ICE AGE!!!!

    http://www.cru.uea.ac.uk/cru/data/temperature/

  86. Clayton B.
    Posted Dec 8, 2007 at 11:04 AM | Permalink

    82, FIFY

  87. Posted Dec 8, 2007 at 11:23 AM | Permalink

    Clayton #85, Thanks! I at first tried using 15 different colors, but the graph came out like mud, so I went back to cycling through 4 bright ones. It’s still a lot more legible than the B&W graph posted on an earlier thread in this category.
    Individual series can be studied in the preliminary paper I linked at #20, before and after Craig’s rolling mean procedure. These may be copied out as WMF, and then pasted into Photoshop and exported as GIF, if desired.
    A few of the horizontal steps may be out of range — I just set the y-axis to (-4, 4), which picked up most of the action.

  88. EW
    Posted Dec 8, 2007 at 11:35 AM | Permalink

    I would have expected the LIA to have set in earlier

    I don’t know, but can’t the climatic changes start somewhere and spread? The start of LIA cooling of the NH surely could have been more prominent in the North than in southern regions. And it wasn’t so bad in the Mediterranean either.

    I remember seeing a documentary about massive witch processes going too far in Germany after the 30-year war (17th century) so that the Pope from Rome felt compelled to send his Legate (envoy) there to find out what’s going on. The Legate was shocked by the state he found the regions north from Alps in – in contrast to the more like “business as usual” state of affairs in Italy and France. There was no food as the harvests repeatedly failed (probably due to low temperatures and fungal diseases), people were few and almost wild. The Legate spoke with the local authorities and lords and they were so firmly set in their opinion, that the witches were the cause of all this bad luck that he had to return back to Rome without making any progress.

  89. Posted Dec 8, 2007 at 12:02 PM | Permalink

    Gavin (on RC) knocks Craig for including the Calvo series, which he says doesn’t start until 1440. Infact, that’s about where it ends:

    (Red X’s are raw data, blue steps are Craig’s extensions).
    (I hope this one works…)

  90. Posted Dec 8, 2007 at 12:06 PM | Permalink

    Gavin (on RC) knocks Craig for including the Calvo series, which he says doesn’t start until 1440. In fact, that’s about where it ends:

    (Red X’s are raw data, blue steps are Craig’s extensions).
    (Oops — I made it a hyper link instead of an image)

  91. Posted Dec 8, 2007 at 12:08 PM | Permalink

    Anyway, the hyperlink on #88 works OK.

  92. steve mosher
    Posted Dec 8, 2007 at 12:24 PM | Permalink

    Hu.. Go to RC and have some fun with Gavin.. see what he says

  93. Larry
    Posted Dec 8, 2007 at 12:31 PM | Permalink

    Is that calendar year, or years in the past?

  94. Posted Dec 8, 2007 at 12:34 PM | Permalink

    No thanks — I think he just misspoke. But note that Craig has the series ending about 1490, not 1440. This is apparently the 50-year C-14 BP issue that was raised.

  95. Posted Dec 8, 2007 at 12:36 PM | Permalink
  96. Posted Dec 8, 2007 at 12:47 PM | Permalink

    Larry (#92) writes,

    Is that calendar year, or years in the past?

    My understanding is that the files Steve posted here on CA all were in calendar years AD.

  97. Posted Dec 8, 2007 at 3:12 PM | Permalink

    Re Craig’s series 12, Calvo, the source data at

    http://doi.pangaea.de/10.1594/PANGAEA.438810?format=html

    gives its first reading as 0.51 kyr BP (11.1 dC). This would
    be 1950 – 510 = 1440 AD, unless they have changed the BP scale
    while I wasn’t looking. So I think Gavin is right on this one,
    and LoehleData12.csv posted on CA is wrong. Since I was able to
    replicate Craig’s results quite closely using this file, it is
    apparently the version he was using.

    Correcting this won’t change the big picture, since Craig’s resolution
    is only 30 years at best anyway. However, it ought to be redone, just for the
    record, after checking the other series.

  98. Clayton B.
    Posted Dec 8, 2007 at 3:15 PM | Permalink

    Hu:
    Press the Img button when drafting your post. When it asks for a url, paste the direct link.

  99. Pat Frank
    Posted Dec 8, 2007 at 3:25 PM | Permalink

    Steve M. wrote: “The post is a “climate audit” type of post and shows that Gavin can be a pretty good “climate auditor” when he turns his mind to it.

    Leading to the obvious question of why Gavin doesn’t invariably turn his mind to it when evaluating all climate-scientific claims. I think this is the most telling illumination of all on the standing of mainstream climatology these days. Opportunistically directed criticism is the mark of r..g…n and politics, but not of science.

    Any fair reading of the peer-reviewed climate literature shows that GCMs can not at all reliably predict future climates, that proxy so-called science has become little more than tendentious assertionism (thank-you M&M), and that the canonical surface temperature record is so error-ridden as to be climatologically meaningless (thank-you Anthony Watts, et al., and Douglas Keenan).

    If Gavin were to forthrightly apply his pretty good climate auditing skills to the supporting corpus of AGW claims, he’d invariably conclude the claims are scientifically insupportable through-and-through.

    And yet to our public knowledge he does not so apply them and, presuming his RC statements reflect his truly held opinions, he does not conclude AGW bogosity. This constitutes a prima facie case that Gavin is not doing science. The alternative explanation is that he is evidently doing consciously partisan politics.

  100. Posted Dec 8, 2007 at 3:47 PM | Permalink

    Observation on the comparative dynamism of CA and RC: over there they have 26 comments on Gavin’s post, eight of which are discussion of how humans lost their hair, and three of which are Mosher’s wonderfully subtle tongue-in-cheek needling. Here we have 98 often robust and compelling posts.

  101. Steve McIntyre
    Posted Dec 8, 2007 at 4:11 PM | Permalink

    #96. I’ve noticed that inconsistencies can arise in how authors handle their top-of-core dating. Sediment authors often are dealing with very big picture. I discussed this in connection with Black (Cariaco) and Richey (Pigmy Basin) where the evidence seemed very strong to me that Richey’s top is dated 50 years or so earlier than Black’s but are plausibly much closer,

  102. Dennis Wingo
    Posted Dec 8, 2007 at 4:14 PM | Permalink

    the uncomfortable truth is you cannot make long, well-calibrated instrumental records appear at the sites where you decide to collect an ice core or lake core or tree ring, and the long instrumental records are almost never collected in places suitable for ice-coring or lake-coring or tree-ring coring, so some long-distance or otherwise relations must be sought.

    There is no excuse whatsoever in the modern satellite communications era for restricting the placement of temperature and other sensors. I design both satellite communications systems and ground based remote sensing hardware and with a few good solar panels, batteries, and small satellites for periodic data collection there is no reason not to have a highly accurate network of climate sensors just about everywhere but the deep arctic and antarctic. Other, more sophisticated means could be used there to close that gap. To make such a statement merely illustrates ignorance relative to the state of modern satellite communications and in situ remote sensing technology.

  103. steve mosher
    Posted Dec 8, 2007 at 4:18 PM | Permalink

    RE 99 needling? Moi? I haven’t the slightest Idea what you are talking about.
    I merely asked a question about the “other 13″ proxies and gavin assumed I’m talking about comparisions to
    Moberg? I didnt mention Moberg. And then when I ask him to cite the source for his numbering of Loehle series,
    he says that butter won’t melt in my mouth. That’s gettin mighty personal, cowboy. Anyway. I think there is fruitful
    ground to plow by asking questions about the role of recons in GCM calibration and C02 sensisivity estimates.
    Gavin has been nice enough to answer my questions so moshpit is in the penalty box. He’s watching game films of
    Gillies and McSorely

  104. bender
    Posted Dec 8, 2007 at 5:36 PM | Permalink

    #79 “club”??? Not sure why you take offence. “strawman”?? In what way?

    My #62 was prompted by the comments of Chris and at RC by Schmidt and also by Steve M, in the post and again, later, in #67. I’ll restate for clarity. If one is going to criticize multiproxy study X for reasons A,B,C then criteria A,B,C, must be applied to multiproxy studies W,Y,Z. If that is not the case, then this is special pleading – a logical error you see frequently at RC (along with poisoning the well). (There was a lot of poison spilled on their treatment of Scafetta & West, for example. So much that the lead author had to make a visit to point it out.) Special pleading is another common AAGW double-standard. So common that it is useful to identify it for what it is.

    I thought it was useful to tie this observation back to Burger & Cubash, who showed that special pleading is ridiculous given the size of the uncertainty on these reconstructions. Again, another common failure of alaramists: to admit – and to understand the significance of – the uncertainty on the historical record.

    I name “names” at CA not to brand an exclusive club, but to point out that the expert critical discussion is not to be found at RC. Indeed, I was trying to be inclusive, by mentioning “Hu”‘s nice graphics.

  105. Jamesg
    Posted Dec 8, 2007 at 5:46 PM | Permalink

    Imagine this scenario out of it’s current context. That is, if for some other reason a group of us gathered temperature plots from 18 parts of the world and none of them showed any similarity to each other, would we see any point at all in combining them into one plot? Probably not. It’s just the idea that there is a global signal that forces these combinations. But clearly neither in the past nor in the present do we have such a signal. At best there are many different regional signals. Comparing very poorly sampled dissimilar, combined past data to poorly sampled, dissimilar, combined present data – at different sampling locations even – seems meaningless to me. What might be useful is to find modern temperatures at these 18 places and compare them, or perhaps just to concentrate on the few places that keep being mentioned by professional climateers as vulnerable – ie the Arctic, Antarctic, Bangladesh, Florida, Australia.

    On that note, I was astounded recently when I looked at an official action plan for Bangladesh which showed a local temperature history plot that had virtually flatlined for the last 50 years, at the end of which was tagged the GCM climate projectons of 1.4 degrees C for the next 50 years. Another one of those obvious GCM absurdities that everyone just ignores.

  106. Posted Dec 8, 2007 at 6:07 PM | Permalink

    hm. Steve, your article does not seem to mention the mistake about dating the series. do you have some evidence that it is false?
    or do you think that 50 years are not important, when someone is making claims about the end of the 20th century?

    Hu McCulloch, the error graph looks pretty good to me. why have so few people commented on it?

    http://www.climateaudit.org/?p=2496#comment-173463

    the main difference between Loehle and Moberg, are the wild claims that Craig is making about a period, that he has little data about.

    it can t be said better than this:

    Only if both goose and gander said:
    “Even keeping in mind that Figure 1 shows 30-year running means, it would indeed seem to show the MWP to be warmer than the late 20th century.”

  107. steve mosher
    Posted Dec 8, 2007 at 6:41 PM | Permalink

    Sod:

    ” Steve, your article does not seem to mention the mistake about dating the series. do you have some evidence that it is false?
    or do you think that 50 years are not important, when someone is making claims about the end of the 20th century?”

    Sod, craig already thanked eric for doing the audit and finding the error. Now craig will correct it.
    Do you think you could write a nice note on RC asking Dr. Mann to correct his latitude/longitude errors?
    I’m trying to check the 5o year error. Could you tell me which series had the error, and what the error
    was? at the start date or end date?

    “Hu McCulloch, the error graph looks pretty good to me. why have so few people commented on it?
    http://www.climateaudit.org/?p=2496#comment-173463

    There are probably less than 6 people here who understand what Hu has done and none at RC.
    If they have an issue with it they will speak up. Then again, we could 1 million people comment
    on it if that would give you a feeling of consensus.

    “the main difference between Loehle and Moberg,
    are the wild claims that Craig is making about a period, that he has little data about.”

    That’s a testable claim: Go read Moberg and list his claims. Go read Loehle and list his claims.
    And then tell us what constitutes wild. I’m just curious.

  108. steve mosher
    Posted Dec 8, 2007 at 6:54 PM | Permalink

    RE 75. Yes. I was going to make more of an issue about it. Simply, if he got the numbering from
    eric or some other source I would assume that he would read the paper and the SI and see that they didnt match
    and then ask eric or whomever where the numbering came from…

    Once I had a kid borrow a plagarized paper from a friend and turn it in. So student A borrows stuff from
    Student B, and student B has commited plagarism using source C. So, when I confront Student A, he argues
    I never copied source C. When I lay the case out, he argues : I didnt copy source C, by friend B did.
    and I just used B’s paper! Anyway. You have ways of checking.

    My sense is that gavin doesnt actually read this stuff. He gets a brief from folks and cobbles something
    together..However, he was no dummy about seeing the problem this presents for Moberg and I would
    anticpate a special pleading ( hat tip bender)

  109. Posted Dec 8, 2007 at 6:57 PM | Permalink

    Mosh #102, “he says that butter won’t melt in my mouth. That’s gettin mighty personal, cowboy.”

    Yeah, he better watch that kind of talk or we might have to conclude he’s less than a manly man. (just kidding, Gavin!)

    I was just struck by the sullen air over there. It’s as if they know bender’s ABCs and XYZs argument on multi-proxies in #102 is the real meaning of Loehle but they can’t talk about it because it’s too horrible to contemplate.

  110. Posted Dec 8, 2007 at 7:15 PM | Permalink

    In #89, I had remarked

    Gavin (on RC) knocks Craig for including the Calvo series, which he says doesn’t start until 1440. In fact, that’s about where it ends:

    In fact, since Calvo counts backwards from 0BP, Gavin is right
    (relatively speaking) that Calvo starts in 1440. So maybe
    this point is just semantic.

  111. Phil.
    Posted Dec 8, 2007 at 7:58 PM | Permalink


    “the main difference between Loehle and Moberg, are the wild claims that Craig is making about a period, that he has little data about.

    it can t be said better than this:

    Only if both goose and gander said:
    “Even keeping in mind that Figure 1 shows 30-year running means, it would indeed seem to show the MWP to be warmer than the late 20th century.””

    Yes although Steve Mc wants to gloss over that. While some of the criticisms of Loehle also apply to Moberg the dating errors don’t necessarily. The claims by Loehle relating to the late 20th century for which he has little data certainly justify criticism.

  112. Phil.
    Posted Dec 8, 2007 at 8:01 PM | Permalink

    Quicktags don’t appear to work re Post # any idea why?

  113. Steve McIntyre
    Posted Dec 8, 2007 at 8:26 PM | Permalink

    #111, Phil, I agree that these particular dating errors don’t apply to Moberg; I agreed that the dating errors were worth noting and even said that Gavin could be a pretty good “climate auditor ” when he wanted. However you notice that he didn’t comment on the dating error in Moberg’s Lauritzen series or Moberg inadvertently using one series twice; or the various errors like that in MBH.

    I reject yor efforts to draw a line between Moberg and Loehle. You say that Loehle made “wild” cliams of a sort that Moberg did not make, citing:

    Even keeping in mind that Figure 1 shows 30-year running means, it would indeed seem to show the MWP to be warmer than the late 20th century.”

    Compare that statement to Moberg’s statement:

    We find no evidence for any earlier periods in the last two millennia with warmer conditions than the post-1990 period.

    Moberg’s claim is more categorical than Loehle’s. Now let’s look at the network of series that contribute to the late 20th century results and Gavin pointed out quite well the very few contributors to the late 20th century in Loehle. As I’ve said repeatedly, these are almost exactly the same roster that are used by Loehle:

    GRIP borehole (match);
    Chesapeake (match);
    Shihua=Beijing stalagmite (match);
    Yang China (match);

    The differences are :
    Moberg uses the very questionable Arabian Sea G Bulloides series;
    Loehle uses the Ge and Holmgren series.

    As noted repeatedly, the G Bulloides series was not calibrated to temperature and is evidence of colder upwelling water.

    The “active ingredient” in Moberg’s different conclusion is supposedly more cold water offshore Oman. And this series BTW has been spliced.

    Loehle needs to correct the dating of a few series, which I’m sure that he will do. Once that’s done, I see no objective basis on which Moberg can be accorded superior status to Loehle.

    Note that I’m not saying that I think that one can put much confidence in Loehle’s reconstruction either. I did a similar calculation for the NAS panel with similar results and described it merely as “apple picking”.

    Going back to Moberg’s claim, in Loehle’s shoes, I would probably have presented these results in a counterfactual way – showing that they disproved Moberg’s allegation that there was no evidence of a warmer MWP. There is some evidence of a warmer MWP; there is also some evidence the other way. Moberg is wrong to say that there’s no evidence and Loehle’s reconstruction shows this rather effectively. I don’t think that it shows the opposite any more than I think that Moberg proved his thesis.

    And as to Gavin caviling about the inability of a couple of proxies to show modern-medieval relationships. I’m OK with that comment. But again, he needs to look in the mirror and ask himself how a few bristlecone pines chronologized by Graybill, in a chronology that Ababneh could not replicate, can show the opposite.

    It’s the hypocrisy that bothers me.

  114. Phil.
    Posted Dec 8, 2007 at 9:43 PM | Permalink

    The “wild claims” remark was not mine, I attempted to link to the absolute post number using the tags however it didn’t work. My criticism of Loehle’s conclusion stands on its own and doesn’t depend on Moberg’s paper. Loehle’s results showed a maximum in 1967 with an appreciable decline thereafter and knew that this was an artifact of his method: “The series ends with a downtick because the last set of points are
    averages that include the cool decades of the 1960s and 1970s.” However his explanation makes no sense since the 60s & 70s are the highpoint of his 20th century reconstruction! Clearly seeing how unreasonable his 20th century reconstruction was he would have been well advised to make no comments about the 20th century. In comparison Moberg said: ” According to our reconstruction, high temperatures—similar to those observed in the twentieth century before 1990—occurred around ad 1000 to 1100,” which seems consistent with his data.

    Steve:
    As noted above, Moberg also said: “We find no evidence for any earlier periods in the last two millennia with warmer conditions than the post-1990 period.” This is every bit as much of an overstatement as the statement you complain of.

  115. Steve McIntyre
    Posted Dec 8, 2007 at 10:14 PM | Permalink

    Gavin commented on the Moberg problem as follows:

    [Response: These things aren’t equivalent. Moberg et al was an attempt to incorporate lower resolution data as well as high resolution data using a new methodology based on wavelet analysis - that is why it was interesting. The specific records they used were not so much the point, it was more a proof of concept. If they were to update it, they would likely have a larger sample and leave out the least well-dated records. More to the point, they seem to be aware of what they were doing and what they were dealing with. With Loehle, there is no new methodology to speak of, and so everything depends on the records and their treatment - you get that wrong, there’s not much left. - gavin]

    Again, Gavin’s hypocrisy is, as always, astounding, as well as his total failure to understand how you establish a new method.

    If the significance of Moberg is simply the introduction of a novel statistical methodology, then Moberg should publish in a statistical journal on data sets with known properties and show that his method works better than the competitive methods. And having done that, move on to data sets where empirical results are being derived.

    As to knowing “what they are doing”, people introducing novel methods in climate articles don’t know the properties of their methods – witness Mannian PCA+ inverse regression, Mann’s first RegEM,… Does Moberg understand the properties of his statistical method any better than Mann (“I am not a statistician”) understood his methods. Of course not.

    By using a simple method, Loehle has a fighting chance of understanding what he’s done – surely that’s an improvement over Wizard of Oz arm-waving. I think that the Mannian style efforts to develop even more unintelligible multivariate methods by publishing these new concoctions as statistical innovations in weakly reviewed (statistically) climate journals such as Journal of Climate are pointless. IF Mann wants to play statistician, publish the method in a proper statistical journal.

    Gavin says:

    With Loehle, there is no new methodology to speak of, and so everything depends on the records and their treatment – you get that wrong, there’s not much left

    Well, I agree with this, but again, the hypocrisy is breathtaking. The Moberg and Loehle collections are essentially the same. As I’ve already shown, if you apply Moberg methodology to Loehle, you get an answer that looks like Loehle.

    Yes, “everything depends on the records”. OF course it does. As I’ve said endlessly, if there was a common “signal” in these proxies, then the methodology wouldn’t matter. Because there’s no common signal, cherry picking is rife. Thus the Team’s addiction to bristlecones and foxtails.

    As to what Moberg would do now, Gavin says:

    they would likely have a larger sample and leave out the least well-dated records.

    Unfortunately this isn’t as easy as all that. I think that the development and utilizaiton of very high resolution sediments is a very worthwhile effort and I’ve been keeping an eye out for over a year for new high-resolution series and have tried to post on them whenever I see one: e.g. Black at Cariaco, Richey at Pigmy Basin. But there’s not as common as one would like. they would likely have a larger sample and leave out the least well-dated records. There are other high-res series e.g. Rein’s grey scale that have terrific resolution, but it’s not clear what they measure. But it’s got a large medieval anomaly. But I haven’t seen all that many that are both well-dated and calibrated to temperature.

    In any event, it’s nice that Gavin is finally coming to appreciate the relevance of data quality – a prominent theme here at CA – in his new-found role of Gavin Schmidt, “climate auditor”

  116. Phil.
    Posted Dec 8, 2007 at 10:35 PM | Permalink

    Re #114 Steve’s comments

    Please Steve take your blinkers off, explain those nonsense statements by Loehle about his end conditions in the 20th century, they’re gobbledygook! Surely you can’t think he believed what he was saying?

    Steve: As I’ve said before, I don’t think that Loehle’s data enables him to conclude that the MWP was warmer than modern any more than Moberg’s enabled him to make the reverse statements. I’m not trying to say that Loehle is right and Moberg is wrong. I’m saying – and I’ve said it many times – that the faults of one apply to the other and vice versa. As I’ve said before, I would have expressed the same point to contradict Moberg. No one has given me any solid reason why Moberg is valid and Loehle isn’t. I think that you also have to look past the little gotchas as well. Mann’s precipitation errors don’t invalidate MBH; it’s invalidated by other things. Suppose that Loehle re-stated his conclusions in a more nuanced way. Would his reconstruction be welcomed into spaghetti-graph world? Of course not. But only because the spaghetti chefs don’t like the answer.

  117. Peter D. Tillman
    Posted Dec 8, 2007 at 10:50 PM | Permalink

    Steve, this is a hard thread to follow, since (I presume) you have deleted some posts and changed the numbering of later posts.

    Could you please, please leave the post numbers undisturbed when you moderate. The simplest method would be a simple “post deleted by moderator” or some similar boilerplate left in place, with the original post number.

    Thanks in advance, Pete Tillman

    Steve: In the software available, if I’m going to edit posts one by one, it takes me a long time to tidy posts one by one. I can move posts to Unthreaded by ticking them in a Move function and save a huge amount of time. I dislike the invasion of post after post by people arguing issues unrelated to the post. I’d ask people to simply not respond to off topic posts or to do so on Unthreaded. Please spend a little energy asking the thread invaders to disciplie themselves. I can’t do everything.

  118. Al
    Posted Dec 8, 2007 at 10:54 PM | Permalink

    Hu McCulloch@#20

    Those confidence intervals appear sensible from a y-amplitude standpoint, but they would appear mighty tightly fitting along the time axis. That is, let’s consider the sharp peak at around 1220. The peak on the upper-bounds line and the peak on the lower-bounds line are also sharp, closely fitting peaks. Seemingly identical peaks with just vertical displacement in fact. If there is any error in the time-axis data, there should be some spread in the peaks on the bounds-lines… yes? A five-year error (0.25% of x-axis scale) would appear to break the confidence interval.

    Were both x-axis and y-axis errors included? Or is the dating that accurate?

  119. Phil.
    Posted Dec 8, 2007 at 11:09 PM | Permalink

    Steve stop dodging, the fault I’m addressing of Loehle is not equally applied to Moberg. His reconstruction shows a peak temperature in 1966 higher than any other since 1300 and yet he explains away his ‘downtick’ in the 1970s as due to “The series ends with a downtick because the last set of points are averages that include the cool decades of the 1960s and 1970s.” According to his reconstruction those decades are the hottest for over 500 years, what’s he smoking? If Mann had made a nonsense statement like that you’d have been all over it, but it gets a pass!
    As for a more nuanced way of expressing his conclusion, to paraphrase he said ‘even though I screwed up the reconstruction of the middle of the 20th century I still think the MWP was warmer than the end of the 20th century’, I suppose ‘since I screwed up the reconstruction of the middle of the 20th century it’s not possible to make any meaningful comparison with the present’ would do.

  120. Phil.
    Posted Dec 8, 2007 at 11:20 PM | Permalink

    Re#20

    The link to your approach doesn’t work for me, how did you deal with the very sparse data, did you use Loehle’s approach of spreading the data over 31 years or did you use the actual data? I’m surprised the error bars don’t get wider at the end of the series (~1980) since there are only ~5 data sets at that point. Thanks.

  121. Peter D. Tillman
    Posted Dec 8, 2007 at 11:44 PM | Permalink

    Re: #117, Steve said

    In the software available, if I’m going to edit posts one by one, it takes me a long time to tidy posts one by one. I can move posts to Unthreaded by ticking them in a Move function and save a huge amount of time. I dislike the invasion of post after post by people arguing issues unrelated to the post. I’d ask people to simply not respond to off topic posts or to do so on Unthreaded. Please spend a little energy asking the thread invaders to disciplie themselves.

    Thanks for the explanation. I don’t hold much hope for disciplining “thread invaders”, and don’t want you to waste time on admin. The rest of us can help by quoting a bit more than just the post number. I’ll add this to the list for the new FAQ, and maybe we need a page of suggestions for posters too.

    Cheers — Pete T, who wishes blog software would pick up more pointers from Usenet software

  122. Posted Dec 8, 2007 at 11:50 PM | Permalink

    Phil, #119:

    As for a more nuanced way of expressing his conclusion, to paraphrase he said ‘even though I screwed up the reconstruction of the middle of the 20th century I still think the MWP was warmer than the end of the 20th century’, I suppose ’since I screwed up the reconstruction of the middle of the 20th century it’s not possible to make any meaningful comparison with the present’ would do.

    I think you need to re-write this, since it’s not clear that even you understand what you are saying. I think you are gratuitously substituting your own half-baked conclusions for Mr. Loehle’s, and since he’s not here to defend himself, and your writing borders on the impenetrable, I’ll leave it at that.

  123. Phil.
    Posted Dec 9, 2007 at 12:02 AM | Permalink

    Re#122

    Since he frequently does post here Loehle will doubtless be able do defend his illogical argument.

  124. Jonde
    Posted Dec 9, 2007 at 12:23 AM | Permalink

    Phil:

    If you would read the original Loehle thread, you could see that your point was criticized within first 20 posts. This is a big mistake from Loehle and if he is going to update his paper, he should omit this kind of statement. We all know his assumption is groundless. It is speculation that is, unfortunately, very common in all the climate change related publication’s Conclusions. This bad habit is way too common amongst climatologist.

  125. Posted Dec 9, 2007 at 6:49 AM | Permalink

    I reject yor efforts to draw a line between Moberg and Loehle. You say that Loehle made “wild” cliams of a sort that Moberg did not make, citing:

    Even keeping in mind that Figure 1 shows 30-year running means, it would indeed seem to show the MWP to be warmer than the late 20th century.”

    Compare that statement to Moberg’s statement:

    We find no evidence for any earlier periods in the last two millennia with warmer conditions than the post-1990 period.

    Steve, i still am not convinced.

    even by just eyeballing your graph, i think that Moberg has a higher ratio of “active” proxies around at the end of his time (1990) than Loehle has for the “end of the 20th century”.

    it would be great, if someone could update your graph:

    http://www.climateaudit.org/?p=2405#comment-167079

  126. Posted Dec 9, 2007 at 6:53 AM | Permalink

    hm, doublequote doesn t seem to work.

    I reject yor efforts to draw a line between Moberg and Loehle. You say that Loehle made “wild” cliams of a sort that Moberg did not make, citing:

    Even keeping in mind that Figure 1 shows 30-year running means, it would indeed seem to show the MWP to be warmer than the late 20th century.”

    Compare that statement to Moberg’s statement:

    We find no evidence for any earlier periods in the last two millennia with warmer conditions than the post-1990 period.

    Steve, i still am not convinced.

    even by just eyeballing your graph, i think that Moberg has a higher ratio of “active” proxies around at the end of his time (1990) than Loehle has for the “end of the 20th century”.

    it would be great, if someone could update your graph:

    http://www.climateaudit.org/?p=2405#comment-167079

  127. Posted Dec 9, 2007 at 8:27 AM | Permalink

    RealClimate has a good discussion of problems with Loehle 2007: link, linking to JEG’s discussion but not to discussion here.

    Now why doesn’t that surprise me? Did Michael Mann ever answer scientific questions by peers on a conference?

    Steve:
    Well, he did tell the NAS panel: “I did not calculate the verification r2 statistic as that would be a foolish and incorrect thing to do”.

  128. Steve McIntyre
    Posted Dec 9, 2007 at 8:49 AM | Permalink

    #126. I don’t think that the ratio of “active” proxies has anything to do with it. My surmise is that the difference between Loehle and Moberg in their most recent period relates almost entirely to the presence/absence of the G Bulloides series. “Ratio” of active proxies is probably irrelevant in the sense that I’m sure that by changing one or two Moberg proxy selections, I can get a Loehle-type result (something that I showed in one of the Juckes threads.)

    So don’t get too excited about active proxies: look at which are the active proxies and what they look like.

    A point to keep in mind in all these studies – and one which I repeat endlessly with few people getting the point. The problem is that there is no common signal. I’ll illustrate this in a slightly different way.

    Take two examples:

    (1) make a network of 10 series by taking the GRIP borehole (with a high MWP like the IPCC 1990 cartoon and a 20th century rise not reaching MWP levels) and blend it with 9 white noise series or 9 low-order red-noise series:

    (2) make a network of 10 series by taking the Mann PC1 and blend it with 9 white noise series or 9 low-order red-noise series:

    Then apply CVM,RegEM or some other typical Team method. In one case, you get back a series with a high MWP and the other you get a HS. By the central limit theorem, the amplitude of the average of the white noise series is lower than the amplitude of the individual series. They cancel out and you get back the outlier series. The methods are spectacularly “non-robust” in the sense of Hampel or Huber. The “robust” reconstruction (again in the sense of “robust” statistics, as the term is understood off the Island and not as perverted by climate scientists) is UC’s reconstruction: a flat line back in time with huge error bars.

    IMHO, the only way to advance past that is to improve the state of proxies so that the present rosters are used to guide collection and entirely new out-of-sample proxies are collected with the program declared in advance as required in medicine.

    In our Almagre case, we didn’t wait and peek at the results. I reported that we had re-sampled Almagre and committed myself to archiving and reporting the results whatever they showed. This is what you have to do in mineral exploration and is long overdue in climate science.

  129. John Norris
    Posted Dec 9, 2007 at 9:53 AM | Permalink

    re Steve McIntyre #115

    Steve McIntyre

    By using a simple method, Loehle has a fighting chance of understanding what he’s done … Steve McIntyre

    Steve McIntyre quoting gavin

    …With Loehle, there is no new methodology to speak of …

    Loehle’s methodology was to keep it simple and transparent. For Climate Science, that is a new methodology.

    re Steve McIntyre #128

    In our Almagre case, we didn’t wait and peek at the results. I reported that we had re-sampled Almagre and committed myself to archiving and reporting the results whatever they showed. …

    Some in the Climate Science are undoubtedly working on a new methodology that makes a HS out of your new data.

  130. jae
    Posted Dec 9, 2007 at 10:12 AM | Permalink

    IMHO, the only way to advance past that is to improve the state of proxies so that the present rosters are used to guide collection and entirely new out-of-sample proxies are collected with the program declared in advance as required in medicine.

    So at this point in time, we may as well rely on written history, rather than any proxies? Do the tree-line proxies offer any hope?

  131. Posted Dec 9, 2007 at 12:09 PM | Permalink

    Al, #118, wrote re my #20,

    Those confidence intervals appear sensible from a y-amplitude standpoint, but they would appear mighty tightly fitting along the time axis. That is, let’s consider the sharp peak at around 1220. The peak on the upper-bounds line and the peak on the lower-bounds line are also sharp, closely fitting peaks. Seemingly identical peaks with just vertical displacement in fact. If there is any error in the time-axis data, there should be some spread in the peaks on the bounds-lines… yes? A five-year error (0.25% of x-axis scale) would appear to break the confidence interval.

    Were both x-axis and y-axis errors included? Or is the dating that accurate?

    I just took the time-axis as “true” and computed y-axis standard errors for each point in time, after applying Craig’s approximately 30-year rolling average. If some of the series had uncertain timing, that would tend to flatten out the signal, so if any signal comes through after averaging, it is probably an understatement of what was really going on.

    It is probably more meaningful with this kind of data to look at even longer intervals than Craig’s tridecades — perhaps even centuries. But for now it’s interesting to go with what he chose (after corrections of Farmer and any BP problems).

  132. Jimmy
    Posted Dec 9, 2007 at 12:22 PM | Permalink

    #128 said

    In our Almagre case, we didn’t wait and peek at the results. I reported that we had re-sampled Almagre and committed myself to archiving and reporting the results whatever they showed. This is what you have to do in mineral exploration and is long overdue in climate science.

    So are you saying that every paleo-reconstruction in climate science looks at the data and then changes it so that they get a “final result” which supports some over-arching ideology??? If so, then why use any of it?

    Steve: That’s not what I said at all. However people have a tendency to quickly report “good” results and delay “bad” results – any delay in a mineral exploration results is usually a sure sign that the results were bad and the promoter is hoping that additional results will be good. For example, long ago, when I noticed delays in reporting the Sheep Mountain update and Bona-Churchill ice core, I predicted that these would be “bad” results. They still haven’t been published but from the Ababneh thesis and a workshop proceeding where Bona Churchill was mentioned, it turns out that both were “bad” for AGW. IT’s not that they changed the data, it’s that the results have not been published 6 years later, whereas, in my opinion, “good” results would have been published by now.

  133. Stan Palmer
    Posted Dec 9, 2007 at 12:33 PM | Permalink

    re 128

    Steve MacIntyre wrote:

    A point to keep in mind in all these studies – and one which I repeat endlessly with few people getting the point. The problem is that there is no common signal. I’ll illustrate this in a slightly different way.

    Can you comment on the robustness tests that Lohle and posters here have reported on – removing proxies and noting that the results persist.

  134. Kenneth Fritsch
    Posted Dec 9, 2007 at 12:36 PM | Permalink

    When Gavin says:

    The specific records they used were not so much the point, it was more a proof of concept. If they were to update it, they would likely have a larger sample and leave out the least well-dated records.

    Isn’t he really giving us a veiw of how the Mannian temperature reconstructions really got motivated and initially accepted with little critique. The methods seemed novel at the time and they showed something that a number of climate scientists wanted to see.

    Cherry picking of proxies was a secondary issue that has not really been addressed by the reconstructionists to date neither in the original reconstruction or its progeny.

    When these novel methods are shown to be lacking in statistical “robustness” what is left but to attempt to wordsmith the debate.

  135. Posted Dec 9, 2007 at 12:36 PM | Permalink

    Phil (#120) wrote, re my #20,

    The link to your approach doesn’t work for me, how did you deal with the very sparse data, did you use Loehle’s approach of spreading the data over 31 years or did you use the actual data? I’m surprised the error bars don’t get wider at the end of the series (~1980) since there are only ~5 data sets at that point. Thanks.

    Try this
    link to ?p=2505#comment-164663. If that doesn’t work, go to the 11/21 thread “MBH98-Style…”, Comment #11.

    I took the raw data as posted on CA, and then used Craig’s approach of spreading each point over approximately 30 years. (Because we handled non-integer years differently, there were some slight differences, but nothing important.)

    My errors bars do get wider at 1980, where his reconstruction ends, since there were only 8 series still active there, vs 14-16 typically in the middle. My OLS se for 1980 is 0.2280 dC, versus about 0.16 dC typically in the middle. See the graphs of my OLS and WLS se’s and the number of included proxies on the paper I linked successfully above at #20 and perhaps also here. The WLS se for 1980 is 0.1650 dC, vs about 0.10-0.11 typically in the interior.

    (I’d insert the graphs themselves here, but am not having much luck with either imageshack or esnips — the latter uploads my image, but then doesn’t give me a URL to it. The former gives me lots of URLs, but they are either thumbnails or don’t work. I may try picasa or tinypic when I get around to it.)

    Just to see what would happen, I tried extending Craig’s reconstruction forward to 2000 (see plot comparing my replication to his reconstruction in paper linked above). The little downtick at the end of his series after 1975 or so turns out to reverse itself around 1985, so it is nothing to get excited about.

  136. Bob Koss
    Posted Dec 9, 2007 at 12:38 PM | Permalink

    Lubos has put up a few remarks concerning Schmidt on Loehle.
    Reference Frame.

  137. Posted Dec 9, 2007 at 12:42 PM | Permalink

    Dear Steve,

    correct me if I am wrong but the particular individual criticisms of the proxies by RC that I have looked at so far seem incorrect. For example, Gavin claims that Calvo et al. 2002

    http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VBC-45Y4JGC-2&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=e80a4ceb6072ae1e15412268cf2f6707

    shouldn’t have been included at all because it starts in 1440. As far as the abstract above says, they go 8,500 years before the present. I even seem to think which related paper goes back only to 1440 – it is Zhao et al. 2000 (also sea cores)

    http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V7P-412RWCX-C&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=7b13733debd09cdc695a237c0119a653

    but this Zhao paper is not used by Loehle. I am also suspicious about the claim that Loehle has confused the BP and BP2000 symbols because he carefully avoided them in his paper and in my opinion, these symbols shouldn’t be used for timescales shorter than many thousands of years.

    Could you please be more specific which Gavin’s criticism of proxies used by Loehle (or Moberg) you agree with (or checked) and why?

    Unlike you, I tend to agree with those who say that in the paleoclimate reconstructions, it is ultimately positive work that makes the real progress. Criticizing someone or even (sometimes) finding legitimate errors is OK but their work is tough anyway, isn’t it? If you think that you can make a better and more controlled reconstruction than Moberg and Loehle, why don’t you do it? Based on other reasons, I think that Moberg and Loehle might be pretty close to reality anyway and work that I could view as superior to Moberg or Loehle is just a better reconstruction, not just a criticism created for the sake of it.

    Of course that I agree that one can invent many types of criticism and the same one may apply to many papers but still, one must be trying to compare different methodologies (and proxies themselves) relatively to each other. Which existing reconstructions do you consider superior over Moberg and Loehle and why? Click my name for my text about Gavin’s reaction to Loehle.

    Best
    Lubos

  138. Bob Koss
    Posted Dec 9, 2007 at 12:43 PM | Permalink

    Hu, I generally grab the bottom link at ImageShack. Never had a problem.

  139. Bob Koss
    Posted Dec 9, 2007 at 12:53 PM | Permalink

    Another possibility is you’re not using the Quicktag Img button to have the image display in your post? The link button won’t display it.

  140. Posted Dec 9, 2007 at 1:15 PM | Permalink

    Lubos —
    See my #110 above. I think that perhaps Gavin, like Calvo, was counting backwards from 1440 AD, in the BP direction, so that in that sense 1440 is when the Calvo series “starts.” The way he phrased it was confusing at the very least, however. I fully agree with you that +/- 50 years isn’t going to change the big picture any, but still Craig should check which if any of his series need correcting and then redo his reconstruction.

  141. Steve McIntyre
    Posted Dec 9, 2007 at 1:18 PM | Permalink

    Luboš, I did a post on Calvo core MD95=2011 here , showing plots of various indices from original data. MD95-2011 is a piston core and values after about AD1440 or so are lost. There is a nearby box core JM… that comes to the present. While dO18 values have been archived so that a reasonable splice can be made, this is not the case for alkenone SST where results from the JM core supposedly didn’t make sense and haven’t been archived (from a CA reader familiar with the matter.)

    One publication on core MD95-2011 expresses dates in BP2000 (Risebrobakken et al Paleooceanography 2003), but the archive at pangaea.de is denominated in BP1950. Loehle incorrectly converted results expressed in BP1950 to BP2000 – it was an error that he promptly acknowledged; it occurred inadvertently and the original authors didn’t help much by their own varying usage. It’s a very high resolution core, worthy of being considered and it would be nice to locate the unarchived alkenone SST data for JM97-948/2A (done in the 1990s). The dO18 values in this high-resolution core are not exceptional in the 20th century.

    I presume that this series was included even though it ended in the 15th century because it had enough values to meet Loehle’s criterion for inclusion even without the later portion. Is this a horrendous error? If so, it’s one that was also made by Esper without him being criticized for it.

    Zhao has nothing to do with this and you should take this off the table.

    I tend to agree with Gavin on the need for better resolution data from the ocean sediment people. I’ve been following this a lot longer than Gavin and have attempted to write posts on any new high-resolution series that I come across (Black on Cariaco, Richey at Pigmy Basin, Newton in the Pacific, McGregor offshore Morocco,the Arabian Sea series, Rein offshore Peru, Khim in the Bransfield Basin, as well as some lake sediment series – Pallcacocha,.., Mt Logan ice core,….) They are aide-memoires as much as anything. Not all of these have been calibrated to temperature by the original authors – no doubt for a good reason.

  142. Walt Bennett
    Posted Dec 9, 2007 at 1:35 PM | Permalink

    Speaking of “petty”: Steve basically concurs with RC on Loehle but (a) accuses them of plagiarism for evidently borrowing from CA info provided by Loehle (isn’t it Loehle’s info and not CA’s?); (b) comlains that RC applies standards to Loehle that ought to also apply to other reconstructions (not that Steve has an actual ptoblem with these rules); and (c) can’t resist another opportunity to trot out MBH98.

    Hey Steve, do you think that by 2008 we can celebrate the tenth anniversary of MBH98 and find something new to pick on?

  143. Kenneth Fritsch
    Posted Dec 9, 2007 at 1:40 PM | Permalink

    One can criticize the entire concept of temperature reconstructions based on showing that the statistical methodologies are insufficient or incorrect, that the proxies were cherry picked to met an end result and that the proxies used for temperature do not appear to have been validated with a reasonable physical model. One could more readily correct the methodology deficiencies and overcome the problems of data snooping the proxies to be used, but, unless one has proxies that one can use with some reasonable level of confidence and give evidence for that confidence, why would anyone want to present their own reconstruction(s).

    The Loehle reconstruction would better have been presented as an example of how a very different temperature series can be reconstructed using real world proxies and how that indicates not so much any thing about the comparison of the Modern to the Medieval WP, but rather an apparent weakness in the entire reconstruction process.

    On the other hand, a defender of past reconstructions and the implied evidence they provide for AGW and the degree of AGW, being aware of the unstated implications of Loehle reconstructions, might well be motivated to wring some differences between Loehle’s and their favorites. That wringing appears to this observer to be currently coming more from the hands than the little gray cells.

  144. L Nettles
    Posted Dec 9, 2007 at 2:00 PM | Permalink

    Re: Walt Bennett
    December 9th, 2007 at 1:35 pm

    Thanks for moving the discussion forward in such a non petty way. Feel better now?

  145. Walt Bennett
    Posted Dec 9, 2007 at 2:18 PM | Permalink

    Re: #144,

    Can’t handle the occasional poke? (I mean you, not Steve…)
    :-)

    Just having a bit of a chuckle…

  146. Posted Dec 9, 2007 at 2:20 PM | Permalink

    I think Steve can take take a huge amount of credit for auditing the work that he has. The fact that such auditing still seems to be required tells me that little has been learnt on this matter. Any scientist should be required to provide all and any data etc for independant replication and I believe that is what Steve is striving for, not just so that he may look at the results but that anybody can do so. Open science should not be an objective it should be the “norm”. That it is not and that that situation can and is defended by many is an outrage that ALL scientists should be ashamed of.

  147. bender
    Posted Dec 9, 2007 at 2:22 PM | Permalink

    #412
    Maybe Walt can’t tell the difference between a critique of a paper vs the flawed methodology on which said paper is based? Walt, nobody’s “moved on”; the flawed methodology of MBH98 is still being employed as though nothing went hopelessly wrong. Mann is not a statistcian. And neither is Rasmus. And neither is Tamino. And neither are you. And it shows.

  148. Steve McIntyre
    Posted Dec 9, 2007 at 2:39 PM | Permalink

    #142. I’ve really been reflecting more on other studies until recently.

    However, in the last cople of months, there have been 3 different attempts to breathe life into the MBH zombie: Juckes et al 2007; Wahl and Ammann 2007 and Mann et al 2007, which uses the same proxy network, complete with many of the same errors.

    So they want to get the last word in and then “move on”. If it makes you happier, I’ll start talking about Mann et al 2007. Discussing this article is simplified by the fact that he even uses the incorrect PC1 methodology of MBH98 and the same bristlecone series.

    Also and this is probably the reason why UC, Jean S and I keep returning to the matter – there are interesting statistical issues in all of this which we’re still working on. We don’t know how MBH99 confidence intervals were calculated. It’s like a missing corner of a crossword puzzle and we’re determined to figure it out. If you find out for us, it will save us some trouble.

  149. yorick
    Posted Dec 9, 2007 at 2:44 PM | Permalink

    Here is an intersting survey of studies with conclusions re the relative amplitudes of CWP and MWP.

  150. steve mosher
    Posted Dec 9, 2007 at 2:51 PM | Permalink

    RE 142. Walt. to be precise SteveM did not accuse them of plagarism. He pointed out
    Some facts.

    1. The Loehle paper does not contain the numbering gavin used.
    2. CA is the source of that numbering.
    3. Here is the definition of plagarism.

    Rorshack test.

  151. Phil.
    Posted Dec 9, 2007 at 2:51 PM | Permalink

    Re149

    Why do you find it interesting and which studies are surveyed?

  152. Phil.
    Posted Dec 9, 2007 at 3:08 PM | Permalink

    Re 150

    According to Gavin in a reply to your question the data came from Loehle himself via Eric Swanson, therefore CA is not the source. Steve Mc has since withdrawn the statement that the only possible source of that numbering system was CA.
    No definition of plagiarism that I’m aware of includes citing the original author and the source of the data, such as “DeMenocal et al (2000) (Loehle #10)”.
    Give it up Steve you’ve had your bit of fun now you’re just being silly!

  153. Posted Dec 9, 2007 at 3:21 PM | Permalink

    Here is an intersting survey of studies with conclusions re the relative amplitudes of CWP and MWP.

    you are not serious about this? co2sciemce?

    http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/qualitative.jsp

    in comparison, the Loehle paper is amsterpiece in accuracy and methodology!

  154. Posted Dec 9, 2007 at 3:21 PM | Permalink

    Here is an intersting survey of studies with conclusions re the relative amplitudes of CWP and MWP.

    you are not serious about this? co2sciemce?

    http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/qualitative.jsp

    in comparison, the Loehle paper is a masterpiece in accuracy and methodology!

  155. steve mosher
    Posted Dec 9, 2007 at 4:03 PM | Permalink

    RE 152. Actually I am just correcting Walt. If I wanted to be silly, I’d compliment you on your intelligence.

    SteveMc never accused them of plagarism
    and neither did I. We were both very circumspect in our observations. You will note, as I stated,
    that I asked gavin very nicely to cite his source, which he claims to have done.

    The bottom line. Gavin, Mann, and Hansen in general refuse
    to acknowledge SteveMc or CA in any way shape or form. I’ll call this tactic stalinist, but understand
    that’s not a pejorative statement.

    One thing people never seem to grasp. When the king characterizes his opponent as a jester, as a fool,
    as someone who has nothing of interest to say, the king simultaneously creates an image of himself,
    like it or not, that is the inverse. And he create expectations of perfection in everything he does.
    Like it or not. Ask Nixon.

    Consequently, when the jester has something of interest to say about something, the king must
    avoid acknowledging him. And when the king makes a mistake, he cannot admit it.

    Then comes the special pleading.

    This is why we have the rule of law; that is, this is why we have the scientific method.

  156. Joe Black
    Posted Dec 9, 2007 at 4:10 PM | Permalink

    we have the scientific method

    Wouln’t that imply:

    – explicitly defining the system under study,

    – Stating the competing hypotheses,

    – Showing the data and methodology of concluding the statistical significance of the accepted hypothesis?

    Just asking, because I don’t seem to find even a good definition of the system.

  157. Susann
    Posted Dec 9, 2007 at 4:42 PM | Permalink

    When reading both RC and CA over the past week, I am forced to think of an episode of Seinfeld when Banya comments, “This is GOLD, Jerry! GOLD!”

    I’m trying to think of a good hockey / war related title for my possible climate policy blog. I’m taking suggestions and will offer full credit to the winner. :)

  158. Posted Dec 9, 2007 at 4:59 PM | Permalink

    #157: How about, “I went to a global warming debate and a hockey game broke out.”

  159. J.C.H.
    Posted Dec 9, 2007 at 5:00 PM | Permalink

    Susann says:
    December 9th, 2007 at 4:42 pm

    “I’m trying to think of a good hockey / war related title for my possible climate policy blog. I’m taking suggestions and will offer full credit to the winner. …”

    Went to a war and a hockey game broke out?

  160. steve mosher
    Posted Dec 9, 2007 at 5:15 PM | Permalink

    RE 157.. If you promise to play clips from the miracle on ice….

  161. Jim Edwards
    Posted Dec 9, 2007 at 5:31 PM | Permalink

    #157, Susann:

    “Slapshot”

    catchy, reminds one of snapshot – which is timely / journalistic, plus a great movie with the Bash Bros.

  162. Cliff Huston
    Posted Dec 9, 2007 at 5:32 PM | Permalink

    RE: #157

    ‘Big stick, no puck’ or maybe ‘Bristle Cone Blues’

    Cliff

  163. steve mosher
    Posted Dec 9, 2007 at 5:37 PM | Permalink

    RE 157 Take this quiz first

    http://www.youthink.com/quiz.asp?action=take&quiz_id=794

    “You just don’t care, you will punish your opponent untill they can not move.
    You have no problem throwing down the gloves. You will push a guy through the glass,
    you will shove him into the ice. Your only mission is to inflict as much pain on your enemy as possible.”

    Hmmm. these quizes are never right.

    “laying on the lumber” would be my choice.
    I also had “mental dentistry” once upon a time ( but thats not hokey or war )

  164. Posted Dec 9, 2007 at 5:52 PM | Permalink

    I want to edit mine for brevity: “a hockey game broke out.”

    Rodney Dangerfield, RIP

  165. Terry
    Posted Dec 9, 2007 at 6:04 PM | Permalink

    Re 157

    “I went to Stockholm and all I got was this lousy hockey stick”

  166. jeez
    Posted Dec 9, 2007 at 6:10 PM | Permalink

    “Penalty Box”

  167. Larry
    Posted Dec 9, 2007 at 6:12 PM | Permalink

    Doesn’t this all belong on unscrewed…..er….unthreaded?

  168. Posted Dec 9, 2007 at 6:30 PM | Permalink

    Phil, #116 writes,

    Please Steve take your blinkers off, explain those nonsense statements by Loehle about his end conditions in the 20th century, they’re gobbledygook! Surely you can’t think he believed what he was saying?

    What Craig actually said in his conclusion was,

    One persistent question is whether the MWP was “really” warmer than the end of the 20th century. Even keeping in mind that Figure 1 shows 30-year running means, it would indeed seem to show the MWP to be warmer than the late 20th century. The eighteen series used here show a mean difference of about 0.3 dC between the MWP and the 20th century (range of 0 to 0.6 dC over the periods). It must be emphasized, of course, that this result is based on limited data.

    His numbers (which admittedly need revision but probably won’t change much) show an average anomaly of +0.367 dC (average se = .160) during the 10th century (901-1000), and +.099 dC (average se = .207) during 1950-1980, 1980 being the last year he reports. The difference is .267 (se from averages = .262), for a t-stat of 1.02.

    This is nothing that an economist would call significant, but wait — this is well above the 66-th percentile of the t-distribution (critical value .41), so that in IPCC-speak, it is in fact “likely”, or to be precise, “likely” that the 10th c was warmer than the portion of the late 20th century that he reports numbers for. (The hyperventilating Cosmo-like italics are de rigeur for IPCC4 confidence statements.)

    The 11th century unweighted average results are not quite so strong: t = 0.52, but even that is within the IPCC likely range.

    When the included proxies are efficiently weighted in inverse proportion to their variances, the t-stat for the 10th c being warmer than the late 20th century rises to 1.36, which is above the 90th percentile of the t-distribution (1.28 with large sample, or 1.30 with 60 DOF, which I would argue is about appropriate here). The 11th century is actually a little stronger (t = 1.37). In IPCC jargon, this make it very likely that both the 10th and 11th centuries were warmer than the portion of the late 20th covered by Craig’s study.

    If we instead just ask if the 10th or 11th c was warmer than the bimillennial average, the IPCC likelihood scale starts to verge on virtually certain (greater than 99% probability).

    Admittedly, I can’t find where Craig committed himself to where the MWP should be, and the adjacent centuries do not register as quite so warm. But still his claim that his data “would seem to show” that the MWP was warmer than the late 20th century is hardly “gobbledygook”, particularly given his emphasis (not quoted by Phil. or other critics here) that he has only very limited data.

    Of course if one were to bring in data not considered by Craig’s study, such as the probably overheated CRU index of urban airport temperatures, and spliced it onto Craig’s series for say 1900-1965 (after which he starts to lose series), one could perhaps argue that the last decade meets or even likely exceeds the MWP. But that would go far beyond the very limited objectives of his study.

  169. steve mosher
    Posted Dec 9, 2007 at 6:31 PM | Permalink

    RE 167. True. Let’s return to the discussion of why humans lost their body hair, present
    company excepted.

    Seriously. The Issues with Loehle have already been hashed out. Gavin ( actually eric )
    added a couple dating issues. This will improve craig’s paper. Hu’s work will improve craig’s
    paper. Maybe JEG will throw in an improvement or two. In the end, I would hazard, that we will
    still be in the same position, more or less: Can’t rule the MWP in, can’t rule it out.

    Those speculations dont undermine the work that craig has done and the contribution that Hu
    has recently made.

  170. Phil.
    Posted Dec 9, 2007 at 6:41 PM | Permalink

    Re 155

    ” Actually I am just correcting Walt. If I wanted to be silly, I’d compliment you on your intelligence.

    SteveMc never accused them of plagarism
    and neither did I. We were both very circumspect in our observations. You will note, as I stated,
    that I asked gavin very nicely to cite his source, which he claims to have done.”

    And since we’re in pedantic mode I didn’t say that you had accused them of plagiarism, I note that you prefer to use innuendo rather than direct accusation, as you have above.

    Gavin did cite his source, I take it from your comment that you don’t believe him?

    “The bottom line. Gavin, Mann, and Hansen in general refuse
    to acknowledge SteveMc or CA in any way shape or form. I’ll call this tactic stalinist, but understand
    that’s not a pejorative statement.”

    I see Gavin acknowledge SteveMc frequently, you appear to think that the only possible source of that material was CA, why not ask Loehle if he gave the same material to Eric that he gave to CA?

  171. Jimmy
    Posted Dec 9, 2007 at 6:42 PM | Permalink

    #141 states

    Not all of these have been calibrated to temperature by the original authors – no doubt for a good reason.

    Is that b/c

    a) there is not enough overlapping SST data with the sediment core to calibrate the proxy data
    b) the researchers believe that the lab experiments where they grow these critters under controlled conditions and measure trace metal incorporation are adequate
    c) the sediment core proxy data actually diverge from measured SSTs, and this divergence is not reported as a cover up…

  172. Susann
    Posted Dec 9, 2007 at 6:42 PM | Permalink

    Doesn’t this all belong on unscrewed…..er….unthreaded?

    Actually I don’t even think it belongs there. :)

  173. Jimmy
    Posted Dec 9, 2007 at 6:49 PM | Permalink

    #168

    I think everyone can agree that there was a warm period around 1000AD in some areas (MWP). The question is: How widespread was it? Can one say it was “global”… I don’t think averaging a bunch of curves will give you the answer to this – regardless of your statistical geek factor. People can even decide on how to calculate a US or global temperature these days with tons of datapoints. How can you do it with much fewer paleoclimate reconstructions???

    A better answer would be draw a line on the a map around those points which show a MWP. Does it cover most of the globe or not?

  174. Jimmy
    Posted Dec 9, 2007 at 6:53 PM | Permalink

    typo in #172. …People CAN’T even decide how to calculate an AVERAGE US or global temperature these days with tons of datapoints…

  175. Phil.
    Posted Dec 9, 2007 at 7:01 PM | Permalink

    Re# 167

    Hu what I was referring to as “gobbledegook” was the following:

    “His reconstruction shows a peak temperature in 1966 higher than any other since 1300 and yet he explains away his ‘downtick’ in the 1970s as due to “The series ends with a downtick because the last set of points are averages that include the cool decades of the 1960s and 1970s.” According to his reconstruction those decades are the hottest for over 500 years, what’s he smoking?”

    How would you define that statement?

  176. Posted Dec 9, 2007 at 7:02 PM | Permalink

    Steve Mosher (#168) writes,

    In the end, I would hazard, that we will
    still be in the same position, more or less: Can’t rule the MWP in, can’t rule it out.

    I disagree — It’s very different to ask whether the MWP was abnormally warm (relative to bimillennial experience, say) than whether it was warmer than the late 20th century. Because of the additional uncertainty of where the late 20th century stands relative to the long-run norm, there’s a lot more uncertainty in the second statement than in the first, as witness the wimpy t-stats in my #167.

    It looks like Craig’s data (after revision) will definitively rule the MWP in, even if it doesn’t necessarily settle the issue of where the CWP stands relative to it.

    IPCC4 (Chapter 6, p. 469) does lamely admit that “The evidence currently available indicates that NH mean temperatures during medieval times (950 – 1100) were indeed warm in a 2-kyr context…” Note that “indeed” or even “indeed” is not on the IPCC likelihood scale. I’m guessing that the appropriate term would be very likely, if not virtually certain.

  177. Posted Dec 9, 2007 at 7:02 PM | Permalink

    Phil: “I see Gavin acknowledge SteveMc frequently. . . ”

    Let’s check the list of links over there at RealClimate. Let’s see we have:

    # Climate Change Education
    # Climate Science
    # Climate Science Watch
    # ClimateArk
    # Climatedenial.org
    # ClimateEthics.org
    # ClimateProgress

    I don’t see any link to Climateaudit. Why? Did the mention of it give Mann the vapors?

    Gavin might acknowledge Steve Mc. CA does not.

  178. Posted Dec 9, 2007 at 7:05 PM | Permalink

    Make that “Gavin might acknowledge Steve Mc. RC does not.”

    Obviously.

  179. Yancey Ward
    Posted Dec 9, 2007 at 7:28 PM | Permalink

    It is pretty obvious that RealClimate should list ClimateAudit amongst it’s links; that they don’t speaks loudly about the true depth of their committment to the integrity of science itself. It is unethical and unscientific to try to deny the existence of critics of one’s scientific work, especially critics as thorough and exacting as the handful found doing the work here on a regular basis.

  180. bender
    Posted Dec 9, 2007 at 8:03 PM | Permalink

    Susann, brainstorm re: hockey & war-themed climate policy blog:
    Reality Check
    Climaticus
    The Arena
    Cygnus
    Climatosphere

  181. Posted Dec 9, 2007 at 8:20 PM | Permalink

    Phil (#174) wrote,

    Hu what I was referring to as “gobbledegook” was the following:

    “His reconstruction shows a peak temperature in 1966 higher than any other since 1300 and yet he explains away his ‘downtick’ in the 1970s as due to “The series ends with a downtick because the last set of points are averages that include the cool decades of the 1960s and 1970s.” According to his reconstruction those decades are the hottest for over 500 years, what’s he smoking?”

    How would you define that statement?

    What Craig wrote was,

    Thus it is not possible to compare recent annual data to this figure to ask about anomalous years or decades. The data show the Medieval Warm Period (MWP) and Little Ice Age (LIA) quite clearly. The weries ends with a downtick because the last set of points are averages that include the cool decades of the 1960s and 1970s.

    So he says that although his series shows big events like the MWP and LIA, it shouldn’t be used to make statements about “anomalous years or decades” As a specific example of such an “anomalous year or decade”, he cites the downtick after 1975.

    Obviously, this inconsequential yet eyecatching downblip was somehow caused by the behavior of the data. Because of his rolling average, 1975 could be affected by data as early as 1960. Mostly likely a relatively warm proxy dropped out circa 1975, leaving only other, relatively cool ones, whence the suddenness of the drop.

    As I noted above somewhere, if his series is continued after his 1980 endpoint to 2000, this blip is just as suddenly reversed c. 1985. Evidently a relatively cool series drops out at that point. This uptick is just as inconsequential as the preceding downtick. Weighted Least Squares softens both movements, but does not remove them.

  182. steve mosher
    Posted Dec 9, 2007 at 8:29 PM | Permalink

    bender, you realize that “bender” is a hockey term?

  183. Susann
    Posted Dec 9, 2007 at 8:48 PM | Permalink

    Stickhandled. :)

  184. Andy
    Posted Dec 9, 2007 at 8:54 PM | Permalink

    Susann, “Faceoff”?

  185. Posted Dec 9, 2007 at 8:55 PM | Permalink

    Continuing #181, it turns out that the specific “perfect storm” that leads to the inconsequential downblip at the end of Craig’s series and subsequent upblip if it is continued past 1980 is that in 1976 #18 Kim, which was running cool, drops in, pulling the series suddenly down. Then in 1983 #2 Gajewski, which was running cool, drops out, while in 1986 #17 Farmer drops in, running warm. The two 80s events roughly offset the 1976 event.

    As Craig pointed out, such anomalous years or even decades don’t mean much of anything. Interpolation would iron such wiggles out, giving a perhaps illusory sense of continuity.

  186. Jimmy
    Posted Dec 9, 2007 at 9:34 PM | Permalink

    #185. and while we’re at the discussion of the 20th century and paleoclimate dataseries – what would the Loehle reconstruction look like if he used the Dye 3 borehole instead of GRIP (Dahl-Jensen et al., 1998)? Why did he pick that one of the two boreholes from Greenland??? He should have at least used an average of the two to be fair…

  187. John Norris
    Posted Dec 9, 2007 at 9:58 PM | Permalink

    With respect to RC not referencing CA, some here may remember that RC went the extra mile to provide a modified Google capability that searches the internet but will filter out CA, and others. They elected to not disclose what websites they filtered out, but if you search climate audit on regular Google, and then through their modified Google search function, you can see what they did.

    http://www.realclimate.org/index.php/archives/2006/10/new-google-search-function/

  188. Posted Dec 9, 2007 at 10:01 PM | Permalink

    RE Jimmy #186
    Good questions, but I’m new to all this stuff, so I don’t know. However, I had just noticed that a few days ago Yorick posted GRIP, Dye3, and Law dome data at

    http://www.gfy.ku.dk/~www-glac/data/ddjtemp.txt, and was wondering the same thing, especially wrt Law Dome, which being in Antarctica would have given Craig some good diversity. The early part of it has a spacing in excess of 200 years, so perhaps that was the issue, but I don’t know. Dye 3 has similar sparse resolution in the first millennium, so maybe that’s its problem as well.

    GRIP is almost as sparse, but Craig has used a pre-interpolated version of it, which gives the impression of a continuous series. In fact, it’s not much more dense than the others.

    Do you know if these are raw temperatures, or reconstructed temperatures backed out of a model of the temperature flow that is slowly ironing out the wiggles in these series?

  189. John Norris
    Posted Dec 9, 2007 at 10:11 PM | Permalink

    Oh one more thing to add to my #187.

    If getting to the truth were more important to me than winning the argument, I would do as Steve did, and reference RC. If I put winning the argument ahead of getting all information on the table, I would do as RC did; not reference CA, and filter it from a customized Google search function.

  190. Jimmy
    Posted Dec 9, 2007 at 10:28 PM | Permalink

    #188. I found a copy of the paper on the website that caused a lot of ruckus a few weeks past at Georgia Tech. In the Dahl-Jensen paper (Oct. 15h in the syllabus at GT), I think they just dropped a fancy thermometer down the hole that was drilled when they pulled out the ice core. In the end, they reconstruct temperatures using a model, but the error looks small for the last couple of 1000 years.

    Check out Fig 4b. I think THAT’S why Dye 3 hasn’t been talked about much…

  191. Phil.
    Posted Dec 9, 2007 at 10:33 PM | Permalink

    Re 186
    ” in 1976 #18 Kim, which was running cool, drops in, pulling the series suddenly down.”
    That dataset ends in 1940: http://doi.pangaea.de/10.1594/PANGAEA.438838

    The downkick starts in 1967 and with a vengeance in 1971.

    With the erroneous dating the data point at ‘1990’ is assumed to start at 1976, so the value measured in 1940 is used in 1976.

    “while in 1986 #17 Farmer drops in, running warm.”
    That dataset ends in 1950: http://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/by_contributor/farmer2005/farmer2005.txt

    In this case the data point at ‘2000’ is assumed to start in 1986, actually the 1950 measurement!

    This isn’t an anomalous decade it’s an anomalous century but since we’re not too worried about the odd 50 years here or there I guess it doesn’t matter?

  192. Joe Black
    Posted Dec 9, 2007 at 11:54 PM | Permalink

    Re #157:

    Cross Checking

    Slashing

    High Sticking

    Icing

    Hooking

    Off Side

    Pull the Goalie

    Hat Trick(s)

    Before your curved hockey stick

    Wrap around

  193. Posted Dec 10, 2007 at 3:03 AM | Permalink

    190, that is one very interesting paper. And to my statistically naive eye, reasonably well tested.

  194. Hoi Polloi
    Posted Dec 10, 2007 at 3:40 AM | Permalink

    RC on AC

  195. Armagh Geddon
    Posted Dec 10, 2007 at 3:55 AM | Permalink

    Over at RC, Gavin said this:

    Finally, I agree, real analyses will win out in the end. I’m hopeful that is too far off. – gavin]

    Never was a truer word said!

  196. PeterS
    Posted Dec 10, 2007 at 5:26 AM | Permalink

    @ Susann

    I’m trying to think of a good hockey / war related title for my possible climate policy blog. I’m taking suggestions and will offer full credit to the winner.

    ‘Clime & Punishment’ ?

  197. steve mosher
    Posted Dec 10, 2007 at 7:57 AM | Permalink

    re 176 Hu..

    I should have been clearer. When I refered to MWP I mean to imply a MWP that is warmer than
    the post 1990s. So, I agrre with you that a MWP is ruled in as your CIs show, but the contention
    that MWP is as warm as or warmer than CWP will have to await updating proxies.. Is that about right
    for your position?

  198. Larry
    Posted Dec 10, 2007 at 8:34 AM | Permalink

    187, Stalin would be proud. That’s really…..uhh……totalitarian of them.

  199. Posted Dec 10, 2007 at 8:51 AM | Permalink

    Phil (191) wrote,

    186
    ” in 1976 #18 Kim, which was running cool, drops in, pulling the series suddenly down.”
    That dataset ends in 1940: http://doi.pangaea.de/10.1594/PANGAEA.438838

    The downkick starts in 1967 and with a vengeance in 1971.

    With the erroneous dating the data point at ‘1990′ is assumed to start at 1976, so the value measured in 1940 is used in 1976.

    “while in 1986 #17 Farmer drops in, running warm.”
    That dataset ends in 1950: http://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/by_contributor/farmer2005/farmer2005.txt

    In this case the data point at ‘2000′ is assumed to start in 1986, actually the 1950 measurement!

    The Farmer (2005) link given says it is quoting age in “calendar age”. The column is headed “cal age (yr)”, with no mention of BP. “Cal BP” would mean dendrocalibrated C-14 dates before 1950 ordinarily, but since there was an explicit reference to “calendar age” in the text and nothing about BP, it would appear that this is indeed “calendar age”. The youngest age given is precisely 0 yr, not -55 yr. I would infer from this that the youngest date is whenever they collected their data, sometime after 2000. What gives you the idea these “calendar ages” are BP1950?

    The Kim (2006) reference gives its first (youngest) age in “kyr BP” as .01, at .02m deep. The second is .08 kyr BP, at .13m. The third is .16kyr. at .24m. The surface rate of accumulation seems to be pretty constant, at about 1/6 cm per year. If 0 BP is 1950, this would place 2006 at roughly 9 cm above the surface. It’s easier to think that their 0BP is about when they did their study, as in one of the 2 official versions of the Calvo table cited by Steve McI here. I can’t get ahold of the Kim paper right now. Does it clarify the table?

    It’s all the same to me either way, as long as we get it straight. The downblip at the end of Craig’s series is simply what the data said was happening, as he understood it, and given his rolling mean approach.

  200. Posted Dec 10, 2007 at 9:04 AM | Permalink

    Jimmy 190 says,

    #188. I found a copy of the paper on the website that caused a lot of ruckus a few weeks past at Georgia Tech. In the Dahl-Jensen paper (Oct. 15h in the syllabus at GT), I think they just dropped a fancy thermometer down the hole that was drilled when they pulled out the ice core. In the end, they reconstruct temperatures using a model, but the error looks small for the last couple of 1000 years.

    Check out Fig 4b. I think THAT’S why Dye 3 hasn’t been talked about much…

    Fig 4b shows a nice MWP, plus a lot of warming in 1955-66, followed by a crash in 1984 to 1927 or 1805 levels, and nothing later. Aside from its sparseness in the 1st millennium, why wouldn’t it be talked about?

    Also, what was the ruckus at Ga tech? Was it caused by this paper or by the website? Speaking of the website, didn’t I read somewhere that the bold gray PS2004 line in the IPCC graph featured on it was truncated by IPCC to eliminate its pronounced un-HS MWP?

  201. Posted Dec 10, 2007 at 9:35 AM | Permalink

    I’m gonna edit Joe Black in #192 and improve slightly:

    CrossCheck

    Good, pithy double-entendre.

    Full credit to Joe.

  202. robp
    Posted Dec 10, 2007 at 10:56 AM | Permalink

    @ Susann

    How about:

    2 Minutes for Instigating, 5 for Fighting

  203. Phil.
    Posted Dec 10, 2007 at 10:58 AM | Permalink

    Re199

    The Farmer (2005) link given says it is quoting age in “calendar age”. The column is headed “cal age (yr)”, with no mention of BP. “Cal BP” would mean dendrocalibrated C-14 dates before 1950 ordinarily, but since there was an explicit reference to “calendar age” in the text and nothing about BP, it would appear that this is indeed “calendar age”. The youngest age given is precisely 0 yr, not -55 yr. I would infer from this that the youngest date is whenever they collected their data, sometime after 2000. What gives you the idea these “calendar ages” are BP1950?

    Because the authors said: “PERIOD OF RECORD: 21 KYrBP – present”

    The Kim (2006) reference gives its first (youngest) age in “kyr BP” as .01, at .02m deep. The second is .08 kyr BP, at .13m. The third is .16kyr. at .24m. The surface rate of accumulation seems to be pretty constant, at about 1/6 cm per year. If 0 BP is 1950, this would place 2006 at roughly 9 cm above the surface. It’s easier to think that their 0BP is about when they did their study, as in one of the 2 official versions of the Calvo table cited by Steve McI here. I can’t get ahold of the Kim paper right now. Does it clarify the table?

    So despite what the authors say in their official archiving of the data you’d rather use another date?

    From the archive ref : AGE Age kyr BP

    It’s all the same to me either way, as long as we get it straight. The downblip at the end of Craig’s series is simply what the data said was happening, as he understood it, and given his rolling mean approach.

    Agreed I have no axe to grind but get the data right, it’s not the first time I’ve seen this mistake made, notably with Carbon dating.
    I agree that it’s what his data says is happening and I assume based on your comments that it’s the result of his sparse data kicking in and out, however given the mess it makes of the 20th century it doesn’t inspire me with confidence about the rest of the reconstruction!

  204. Wondering Aloud
    Posted Dec 10, 2007 at 11:21 AM | Permalink

    Frankly I can’t find many strong threads in the AGW argument. Each and every one seems to have a whole lot of bias and uncertainty. When people try to dismiss solar influence with Milinkovitch cycles like Chris in #35 does it shows they don’t understand that issue at all.

    Every “proof” he sites in #35 is doubtful at best. There may be a signature piece of evidence of AGW, I’ve seen some I think might pan out, but Chris missed them all. I wonder if he is an agent deliberately trying to discredit AGW.

    On a scientific method note. For current catastrophic glogal warming hypothesis to be correct they must be right on every particular demonstrating that they haven’t got a mistake in their proposed mechanism. That is the way a THEORY in science works, it must explain the observed data. If a theory fails to do this it must be modified or discarded.

    Like it or not the elimination of the MWP in the hockey stick graph is unsupported by the data. If you want to prove that 20th century warming is predominently human in origin you better find another way.

  205. Sam Urbinto
    Posted Dec 10, 2007 at 12:30 PM | Permalink

    For those curious about absorbtion bands. The band at about 4 micrometers is the only wavelength where CO2 has no competition. Interesting, isn’t it? Move along, there’s nothing to see here.

  206. Walt Bennett
    Posted Dec 10, 2007 at 1:12 PM | Permalink

    Re: #148,

    Steve,

    In other words you will leave MBH98 behind and focus instead on MBH99? :-)

    In all seriousness, of course you would continue to examine the puzzle if you have not figured out all the pieces. To the occasional visitor this can have the appearance of “obsession”.

    I will declare that you and several others here are clearly obsessed with RC, even though you trounced them in the popularity contest.

    I’d be much more inclined to be a regular visitor to this site if you could focus much more on auditing the science and much less on catty little carping.

    Call my little comment an experiment. Look how much dust it stirred up.

    Haven’t we all got more important things to do?

  207. yorick
    Posted Dec 10, 2007 at 1:15 PM | Permalink

    Jimmy

    while we’re at the discussion of the 20th century and paleoclimate dataseries – what would the Loehle reconstruction look like if he used the Dye 3 borehole instead of GRIP (Dahl-Jensen et al., 1998)? Why did he pick that one of the two boreholes from Greenland??? He should have at least used an average of the two to be fair…

    You can go here to read a discussion of the GRIP and DYE-3 boreholes. It might be that one of them, GRIP, is more recent and uses updated techniques. But if you insist on picking that cherry, go ahead and use the outdated one.

    http://www.gfy.ku.dk/~kka/icecores_palaeoclimate.pdf

  208. Jimmy
    Posted Dec 10, 2007 at 4:58 PM | Permalink

    Yorick (#207) and Hu (#200)

    GRIP was a European hole drilled in the early 1990’s. Dye-3 was a US hole (GISP) drilled in 1981 (which is indeed warmer as Yorick noted).

    GRIP was further north and more in-land. Dye-3 was further south and more towards the coast.

    As ice-core age models are updated constantly, and as the recent past has been subject to the least amount of ice-flow, there is no reason to throw out the Dye-3 data as Yorick suggests.

    The MWP in Dye-3 was about the same temperature as the 1950’s-1970’s. Incidentally, in the file that Hu pointed to in entry #188, the temperature came “crashing down” in Dye-3 in 1984. 3 years after the hole was drilled. Strange. Otherwise, there is only a monotonic increase to present beginning in the late 1800’s.

    The MWP in GRIP is ~1degC warmer than the 1950-1970 period. This may be b/c of the position on the continent, but who knows.

    The point is: when Loehle uses only the GRIP record in his simple averaging for the reconstruction, it is not factoring in the real temperature response of Greenland over the last 2000 years. I’m just saying to be fair, he should use them both. And NOT just the one that has a relatively warmer MWP than present. That’s not very scientific. To use them both would mean NO cherry-picking.

  209. Pat Keating
    Posted Dec 10, 2007 at 5:09 PM | Permalink

    205 Sam
    I’m not sure of the point you are making. (Perhaps it’s in response to a post I’m not aware of). Could you elaborate a little?

  210. mccall
    Posted Dec 10, 2007 at 5:39 PM | Permalink

    #157
    “The Hockey Stick & The Boomerang!”

    Hansen vs. Hansons — “Puttin’ on the foil!”

  211. Sam Urbinto
    Posted Dec 10, 2007 at 5:49 PM | Permalink

    Pat, generic comment about keeping other things in mind than a gas that absorbs IR.

    A quick look at the atmospheric raditation transfer on that chartshows that almost all absorbtion and scattering is due to the things we have no real direct control over — water vapor, oxygen, ozone and rayleigh scattering. Only at ~3.5 um does CO2 show a signal on its own, and a chunk of that is where nitrous oxide also plays a large part (a little wv also) and doesn’t even take particulates into account.

    Look at these margin of error, and know why I’ll die happy if nobody ever mentions CO2 again and starts focusing on the system, of which CO2 is a minor part (human created or not)

    http://en.wikipedia.org/wiki/Image:Radiative-forcings.svg

  212. Pat Keating
    Posted Dec 10, 2007 at 5:56 PM | Permalink

    211 Sam
    Thanks for kindly helping the simple minded. I agree, by the way, and think the sun has been badly neglected. It is not de-rated up-front by a factor of 3000 like CO2, for a start.

  213. Sam Urbinto
    Posted Dec 10, 2007 at 6:26 PM | Permalink

    I’m just sick of everyone who is making some kind of simple x=y comparison moan about how they’re not doing something when they are. :)

    This relates to Loehle in general; he took existing proxy papers and combined them, and just like the “But I’m not saying CO2=TEMP+ of course we know there are other variables.” nonsense, we are getting complaints on certain aspects of his paper that apply equally to others; that whole simple answer to a complex question that smacks of hypocracy thing. You know, opinions stated as fact. Par for the course.

    Just sayin’.

  214. Rich in Az
    Posted Dec 10, 2007 at 7:09 PM | Permalink

    re #205 & 211 Sam Urbinto

    what struck me about the graph was that there seems to be 100% absobsion and scattering already in the bands for CO2.

  215. yorick
    Posted Dec 10, 2007 at 7:17 PM | Permalink

    Jimmy,
    Whatever. Pick your cherry. I don’t care. In 1983 I was listening to vinyl records. The Dye core shows amplitude differences from the GRIP core. You want to jump on them and use a core that ended in 1983 in the place of one that ended in 1995 becuase you are fishing for that uptick at the end. An awful lot of scientists say that the warming signal from CO2 didn’t even show up until 1980.

  216. Jimmy
    Posted Dec 10, 2007 at 8:07 PM | Permalink

    Yorick (#215)

    You have missed my point in your unfounded anger and resentment. My WHOLE point, that goes for ALL reconstructions, is that ALL data available should be used. I don’t think that anyone would disagree when I say there is not enough paleoclimate data. Period.

    I can see why one would not use a series if it questionable (ie. BCP’s)… but why leave out good data???

    Hopefully in Loehle’s next try (and I’m it seems likely that he will update the 2007 paper), he will keep that in mind.

    I’m just trying to get to the truth. That is the point, right???

  217. yorick
    Posted Dec 10, 2007 at 8:26 PM | Permalink

    If you use ALL data you are bound to get a lot of garbage. This will give you a nice flat climate as all of the random data averages out to an anomoly of zero. Then you can graft on the instrument data and get a nice hockey stick. I think a far better approach would be to select data for quality, not for desired outcomes, such as extending the 1983 peak in the DYE 3 core to the present. I am certainly not angry, nor resentful. It kind of reminds me of how my sister used to come up with one “fair” solution after another to Bush Gore 2000 Florida. The common thread? Gore would be president under every one of them. “Fairness” is no standard.

  218. Jimmy
    Posted Dec 10, 2007 at 8:41 PM | Permalink

    Yorick (#218)

    The climate series would only average out to zero/flat if the MWP was not global. If it was global, wouldn’t it still be there?

  219. Posted Dec 11, 2007 at 9:00 AM | Permalink

    Jimmy #217 wrote,

    My WHOLE point, that goes for ALL reconstructions, is that ALL data available should be used. I don’t think that anyone would disagree when I say there is not enough paleoclimate data. Period.

    I can see why one would not use a series if it questionable (ie. BCP’s)… but why leave out good data???

    Hopefully in Loehle’s next try (and I’m it seems likely that he will update the 2007 paper), he will keep that in mind.

    I’m just trying to get to the truth. That is the point, right???

    I agree with Jimmy that tutti frutti is the best way for Craig to go — include the cherries, the lemons, the apples, the kiwis, the uglis, and anything else that comes to hand that has been T-calibrated in a peer-reviewed pubication (or in conjunction with one?). Craig’s signature approach is that he is excluding sticks and twigs (treerings), but then he is making fruit salad, not granola.

    As for Yorick’s objection in #218, “If you use ALL data you are bound to get a lot of garbage. This will give you a nice flat climate as all of the random data averages out to an anomoly of zero.”, Jimmy is right in 219 that this will only happen if there is no global signal.

    To be sure, the unweighted average will come out with a big standard error. However, this can be objectively improved upon in a second round of weighted least squares, which looks at the variance Vj of each series j about the overall time-specific means (not about its own mean over time as Gavin advocated in his RC note), and efficiently weights each inversely to Vj. The variances I computed using the original, uncorrected Loehle (2007) data are in the second column below. The third column has the corresponding standard deviations (in dC), and the last column has the WLS weights 1/Vj:

    1.0000 0.1588 0.3986 6.2953
    2.0000 0.2198 0.4689 4.5489
    3.0000 1.7430 1.3202 0.5737
    4.0000 0.2102 0.4585 4.7571
    5.0000 0.2100 0.4583 4.7612
    6.0000 0.0417 0.2042 23.9714
    7.0000 0.3294 0.5740 3.0356
    8.0000 0.1886 0.4343 5.3019
    9.0000 0.1480 0.3848 6.7550
    10.0000 1.7116 1.3083 0.5843
    11.0000 0.3818 0.6179 2.6195
    12.0000 0.1028 0.3206 9.7304
    13.0000 0.0400 0.1999 25.0284
    14.0000 0.3199 0.5656 3.1258
    15.0000 0.2669 0.5166 3.7463
    16.0000 0.1978 0.4447 5.0561
    17.0000 0.0877 0.2962 11.4003
    18.0000 0.1078 0.3283 9.2782
    It may be seen that #3(Cronin) and #10 (deMenocal) are truly rotten apples that may as well be pitched — and effectively are by WLS. #17 (Farmer) on the other hand, ugli though it may be on the exterior, turns out to add a valuable, if exotic, flavor to the mix.

    I just got a note from Christa Farmer (now at Hofstra) that the ages in #17 are indeed measured in BP1950 years. However, I got another from Peter deMenocal, who was a co-author with Farmer on #17, that the dates are in any event so approximate in both #17 and #10 that neither should have been used by Craig. It seems they took a few C-14 dates along the core, the first around 1800 BP, and then extrapolated to where “year 0″ (1950) would be. The depths are then measured from this point, wherever it may lie on the core.

    While it would be foolish to use such a series by itself to make sweeping statements about climate change, noise is not in itself a problem if one is going to average together several noisy series. So my advice for Loehle II at this point would be to go ahead and throw both of these in, along with Dye 3, Law Dome and any other peer-reviewed T-calibrated series, at least for a first cut unweighted average. But then use WLS in a second round to effectively get rid of the rotten apples while retaining the flavorful uglis.

    Note that the criterion being used by WLS is not the conformity of the series to one’s preconception of whether there was or wasn’t a MWP or whatever, but rather its conformity to the signal in the other series. Gavin’s proposed normalization would instead weight each series by how flat it is — a good way to fabricate a nice HS shaft!

  220. Posted Dec 11, 2007 at 9:49 AM | Permalink

    Someone on an earlier thread mentioned a series from Hells Kitchen Lake WI that seemed to meet Craig’s criteria for inclusion but which he had overlooked in Loehle (2007). Does anyone know where to find it?

  221. yorick
    Posted Dec 11, 2007 at 8:15 PM | Permalink

    Jimmy,
    I see your point. The garbage series should cancel each other, roughly, and the good series should influence the final product.

    By the way, the Law Dome shows a nice MWP and LIA in the SH, not that that is a criteria for including it. It just does.

  222. Jimmy
    Posted Dec 11, 2007 at 9:09 PM | Permalink

    Yorick,

    Plot up the data in #188 that Hu posted. It is a little more interesting that a “MWP and LIA”. The temp in the SH leads the temp in the NH during those excursions you speak of. These were climate anomalies that

    1) appear global
    2) however, are NOT sychronous in the 2 hemispheres
    3) the SH leads the temp change in the NH by quite a bit

  223. Mark T
    Posted Dec 12, 2007 at 1:42 AM | Permalink

    The climate series would only average out to zero/flat if the MWP was not global. If it was global, wouldn’t it still be there?

    Um, this is true only if the proxies are truly proxies for temperature, the effect is fairly consistent through all time and all confounding factors are accounted for. The series could easily average out to zero if they simply aren’t measuring temperature, or they do so non-linearly, or their statistics exhibit non-stationarity, or the “inputs” are correlated. This is not unlike the whole “you can fit an elephant” idea…

    I think yorick unwittingly noticed this with:

    and the good series should influence the final product.

    Ya gotta have some “good” series to find anything (actually, you need at least enough to describe the space of your inputs lest you wind up with an under determined system).

    Mark

  224. yorick
    Posted Dec 12, 2007 at 6:58 AM | Permalink

    Jimmy, I was looking at the Law Dome borehole temps, and the temp resolution is not that great. I was thinking about your point, and decided that there is just too much slop in the time ranges for me to decide, anyways. But it does seem to lead in the SH within the margin of error.

    Maybe Lea (see day two summary of AGU) is correct, southern ocean outgassing of CO2 influences NH. Orbital forcings are different, so differences are to be expected.

  225. steven mosher
    Posted Dec 12, 2007 at 10:09 AM | Permalink

    There is a benefit to narrowing the estimates of the LIA as much as possible.
    There is a benefit to extending the global coverage of this time period.

    Eye of the needle.

  226. steven mosher
    Posted Dec 12, 2007 at 10:09 AM | Permalink

    There is a benefit to narrowing the estimates of the LIA as much as possible.
    There is a benefit to extending the global coverage of this time period.

    Eye of the needle.

  227. Larry
    Posted Dec 12, 2007 at 10:24 AM | Permalink

    When you get that page full of incoherent error messages…..don’t submit again. Hit ‘back’ on the browser, and then refresh. You won’t lose the comment in the box, and 99% of the time you’ll find that the comment took.

  228. Nicholas
    Posted Dec 12, 2007 at 10:41 AM | Permalink

    Susan:

    I’m trying to think of a good hockey / war related title for my possible climate policy blog. I’m taking suggestions and will offer full credit to the winner.

    “30 Seconds Over Kyoto”

  229. Sam Urbinto
    Posted Dec 12, 2007 at 1:29 PM | Permalink

    “Launching the puck with a trebuchet.”

  230. Posted Dec 12, 2007 at 1:50 PM | Permalink

    Suzann: “Battle of the Puck Ice”

  231. Larry
    Posted Dec 12, 2007 at 1:54 PM | Permalink

    “Get the puck out of there”?

  232. pochas
    Posted Dec 12, 2007 at 2:16 PM | Permalink

    “Two Minutes for High Sticking”

  233. Andrey Levin
    Posted Dec 12, 2007 at 10:07 PM | Permalink

    “Weather Change”

  234. Philip_B
    Posted Dec 13, 2007 at 1:05 AM | Permalink

    “Ice Time”

4 Trackbacks

  1. By Dropping the P-Bomb « Deep Climate on Aug 14, 2009 at 4:09 PM

    [...] “realclimate on Loehle” [...]

  2. [...] Menne and NOAA in an exemplary manner.  At blog level Gavin Schmidt at RealClimate has certainly incorporated information without acknowledgement, probably out of pettiness as Steve McIntyre [...]

  3. [...] Menne and NOAA in an exemplary manner.  At blog level Gavin Schmidt at RealClimate has certainly incorporated information without acknowledgement, probably out of pettiness as Steve McIntyre [...]

  4. [...] Menne and NOAA in an exemplary manner.  At blog level Gavin Schmidt at RealClimate has certainly incorporated information without acknowledgement, probably out of pettiness as Steve McIntyre [...]

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