Tamino’s Trick: Mann Bites Dog

Self-described “Hansen bulldog” Tamino, writing at NASA’s realclimate blog hosted by Hansen’s other bulldog (Gavin), wrote:

As another example, Montford makes the claim that if you eliminate just two of the proxies used for the MBH98 reconstruction since 1400, the Stahle and NOAMER PC1 series, “you got a completely different result — the Medieval Warm Period magically reappeared and suddenly the modern warming didn’t look quite so frightening.” That argument is sure to sell to those who haven’t done so. But I have. I computed my own reconstructions by multiple regression, first using all 22 proxy series in the original MBH98 analysis, then excluding the Stahle and NOAMER PC1 series.

As always with the Team, you have to watch the pea under the thimble. Tamino has totally misrepresented and misinterpreted Montford on this point. Neither Montford (nor I) ever made such an assertion. The only person to do so, as I’ll show below, was Mann himself.


In our 2005 (EE) article where we analyzed the various permutations and combinations, our concern wasn’t with the Stahle-NOAMER PC1 pair, but with the Gaspe-NOAMER PC1 pair. In our 2005 article, we closely examined both the Gaspe and bristlecone proxies – believing then, as now, that if these series had unique capability to interpret world climate fields, then readers should be enabled to as much as possible about the unique characteristics of these groves.

The Stahle-NOAMER PC1 combination wasn’t mentioned in our articles. Nor did we (or Montford) present the particular sensitivity combination that Tamino now purports to rebut. This combination arose not in our analyses, but in Mann’s own analyses.

In their November 2003 response to MM2003, Mann presented a graphic that showed elevated early 15th century values with variations of three series (1) no NOAMER PC1; (2) no Stahle PC1 and (3) the shorter archived version of Twisted Tree, rather than the longer grey version used in MBH98 (in which early portions did not have the usual minimum numbers of trees.)
Mann et al 2003, Figure 1. The three datasets in the caption are the NOAMER PC1, the Stahle PC1 and Twisted Tree.

As Montford accurately reports in HS Illusion, I was extremely interested in this particular graphic because Mann et al themselves, in effect, conceded that the differences arose out of only a few series. Montford described this as follows:

Mann may well have felt that he had done enough to fend off McIntyre’s criticisms but McIntyre’s perspective was quite different. Without realising that he’d done it, Mann had inadvertently shone a little light on another murky corner of his famous paper. To McIntyre, what made Mann’s response most interesting was not the fact that Mann had used an undisclosed methodology, but the fact that if you left out just two of the proxy series – the Stahle and NOAMER PC1s – you got a completely different result – the Medieval Warm Period magically reappeared and suddenly the modern warming didn’t look quite so frightening. What this meant was that Mann’s result – that the Medieval Warm Period didn’t exist – seemed to rest on just a tiny fraction of his data. The rest of the series were just ‘noise’. Mann may well have been justified in using a stepwise procedure, but if his conclusions depended on just two PC series, then they could hardly be considered robust.

Note Tamino’s selective quotation from Montford’s book. Montford was describing my reaction to Mann’s 2003 response to MM2003. Neither Montford (nor I) claimed that Mann’s calculation in his November 2003 response were correct. Montford described the impact of Mann’s calculation on me. At the time, we hadn’t isolated the precise difference between our calculation and Mann’s calculations. While Mann attempted at the time – mostly successfully in the climate science community – to distract attention to replication details involving unreported aspects of their methodology (an experience which informs some of my present procedures in dealing with these guys), his own diagram showed me that the differences arose from only a few series. Which we proceeded to analyse in detail.

The Twisted Tree series was quickly seen to be moot as it did not come into play in the AD1400 step. (Mann’s defence of his version was unconvincing to say the least. Our comparison used the archived version which did not go back as far as the grey version. The early portion of the grey version included periods with less than the minimum number of cores for a chronology under Jacoby-d’Arrigo methods.) Given that MBH claimed to have screened chronologies to ensure a minimum number of cores, their insistence in this instance of using a chronology portion that did not meet their reported QC standards seemed odd, to say the least. Needless to say, no one in the “community” cared.

Our analyses also quickly showed that the presence/absence of the Stahle PC1 didn’t matter as it didn’t have a HS shape. This was a non-issue in our own presentations – Tamino’s mention of Stahle was therefore a red flag to both Montford and me. Needless to say, the (bristlecone) NOAMER PC1 did “matter”, as did another series (Cook’s 1983 Gaspe chronology), even though it hadn’t been mentioned in the 2003 MBH response.

It’s hard to say precisely what Mann did in his 2003 diagram showing such a large impact from the NOAMER PC1-Stahle PC1. Our own calculations yielding a high early 15th century also involved Gaspe. At the time of MM2003, we had not fully appreciated the important role of the unique and unreported extrapolation of the Gaspe series, but became aware of it very quickly in late 2003 and were fully aware of the issue when we submitted out 2004 Nature articles. (There is a later unpublished version of Gaspe that doesn’t have a HS shape – an issue that is avoided by the Team.)

I presume that Mann’s 2003 diagram inadvertently used the actual Gaspe data (rather than the version with the unique and unreported extrapolation) and this led to a more dramatic result than he might have intended – but this is only speculation.

Mann re-visited this calculation in a graphic in the unpublished 2004 Mann et al submission to Climatic Change shown below. This has a different result than the 2003 diagram, showing high early 15th century results from a Gaspe-NOAMER PC1 combination – a point on which we were and are in agreement with them.


Mann et al 2004 submission to Climatic Change, Figure 2. “Treeline” in this context meant Cook’s 1983 Gaspe series.

A point that is little understood because of constant disinformation from the self-appointed bulldogs is that our results and those of Wahl and Ammann (or Mann) are in close agreement with sufficiently well-defined calculations – a point that we made in MM2005 (EE) as follows:

We emphasize the consensus between ourselves and Mann et al. on the results of sufficiently well-defined calculations. The PC calculations themselves are replicated between parties to complete accuracy. Differences remain in the emulations of NH temperature (given the PC series), but Mann et al. [2003] showed a calculation with high early 15th century results if the North American PC1 were unavailable; the comments in Mann et al. [2004b] about the effect of the PC4 confirm this overall agreement if assumptions are sufficiently well defined.

In December 2005, as I’ve reported on many occasions, recognizing this point, I proposed to Caspar Ammann that we attempt to write a joint paper accurately setting down points of empirical agreement e.g. the results of 2 covariance PCS versus 5 covariance PCs; the impact of the presence/absence of bristlecones; verification r2’s, etc. Ammann refused, saying that this would be “bad for his career”. Whether or not it would have been bad for Ammann’s career, I think that the “community” would have benefited, if Ammann had accepted my proposal. (The offer was made in writing and including a proviso that the parties could go back to square one if they were unsuccessful in achieving a joint paper; it was a very fair offer.)

Instead, the Team’s approach has always been one of misdirection, Tamino’s post and Gavin’s commentary being only the most recent examples. Tamino’s realclimate post totally misrepresented Montford’s paragraph and purported to rebut a claim that neither Montford (or I) ever made. It wasn’t Montford (or I) that presented the Stahle-NOAMER PC1 combination that Tamino purports to refute. It was Mann himself.

Reasonable people can disagree as to whether the post should be entitled “Mann Bites Dog” or “Dog Bites Mann”, but surely no one can dispute that They are The Gang That Can’t Shoot Straight.


125 Comments

  1. per
    Posted Jul 27, 2010 at 4:48 PM | Permalink

    errr… “dog bites Mann”, surely ?

    it is still amusing :-)

    Steve: you have a point. I’ve added a sentence noting that reasonable people can disagree on this point.

  2. Sean
    Posted Jul 27, 2010 at 4:49 PM | Permalink

    small typo:

    “believing then, as now, that if these series had unique capability to interpret world climate fields, then readers should be enabled to _know_ as much as possible about the unique characteristics of these groves”

    word “know” is missing. feel free to delete this comment after correcting.

  3. Gerald Machnee
    Posted Jul 27, 2010 at 4:54 PM | Permalink

    You beat me to the punch line, Steve. I do not even want to speculate on his explanation.

  4. Martin
    Posted Jul 27, 2010 at 4:56 PM | Permalink

    Your skill and determination should be embraced by the very people who show you such scorn.

    Martin

  5. Peter Dunford
    Posted Jul 27, 2010 at 5:04 PM | Permalink

    Tamino and Schmidt are self confident enough, putting it mildly, that they don’t bother to fact check within the Team. But then, why would they? Team errors never “matter”.

  6. Benjamin
    Posted Jul 27, 2010 at 5:08 PM | Permalink

    Re=-0.64 in the Mann et al 2004 submission to Climatic Change, Figure 2 “NO ITRDB/Stahle/Treeline” graph … what does this mean ?

    Steve- it’s never very clear. My interpretation in this context is: Treeline is an alias for Gaspe; Stahle is the Stahle PC1 (this is pretty much low-order red noise and doesn’t have much to do with the price of eggs); ITRDB is an alias for the NOAMER PC1, which was made up of Graybill bristlecone chronologies, which have hair on them as discussed on many occasions here.

  7. Fred
    Posted Jul 27, 2010 at 5:17 PM | Permalink

    Really, you are going to defend that quote from Montford?

    I don’t recall anyone else ever saying the Medieval Warm Period was in the 15th century.

    Nor do I recall Mann et al claiming that reconstruction steps with large and negative RE were valid reconstructions.

    Mann’s point was surely that removing data degraded the reconstruction, not that it ‘restored’ the MWP.

    Steve: for me at the time, the significance of Mann’s reply was – as I said- that the differences could be pinned down to a couple of proxies. “Disaggregated” so to speak. :)

    • Tom Gray
      Posted Jul 27, 2010 at 5:56 PM | Permalink

      Nor do I recall Mann et al claiming that reconstruction steps with large and negative RE were valid reconstructions

      What about negligible r^2? He seems to think that sich reconstructions can be valid.

      • Alan D McIntire
        Posted Aug 28, 2010 at 9:26 AM | Permalink

        See

        http://www.meteor.iastate.edu/classes/ge415/papers/Mann_et_al_Nature1998.pdf

        From pg 785 of the Nature paper:

        “b is a quite rigorous measure of the similarity between two variables,
        measuring their correspondence not only in terms of the relative departures
        from mean values (as does the correlation coefficient r) but also in terms of the
        means and absolute variance of the two series. For comparison, correlation (r)
        and squared-correlation (r2) statistics are also determined. The expectation
        value for two random series is b ¼ 21. Negative values of b may in fact be
        statistically significant for sufficient temporal degrees of freedom. Nonetheless,
        the threshold b ¼ 0 defines the simple ‘climatological’ model in which a series
        is assigned its long-term mean. In this sense, statistically significant negative
        articles values of b might still be considered questionable in their predictive or
        reconstructive skill. Owing to the more rigorous ‘match’ between two series
        sought by b, highly significant values of b are possible even when r2 is only
        marginally significant.”

        The formula he was referring to was RE, not r^2-

        • Alan D McIntire
          Posted Aug 28, 2010 at 9:29 AM | Permalink

          Sorry, my reproduction didn’t copy true. This imbedded phrase should read

          Nonetheless,the threshold b= 0 “

        • Stan Plamer
          Posted Aug 28, 2010 at 10:00 AM | Permalink

          r2 was not marginally significant in his reconstruction. It was esssentially 0.

    • Szerb fan
      Posted Jul 28, 2010 at 8:12 AM | Permalink

      Agreed, in that most sensible (non-Mannian) reconstructions have a peak nearer 1200 AD.

      But you cannot choose what data to use, simply by the beneficial effect it might have on the reconstruction statistics! It might be nice for Mann to include Gaspe for these reasons, but MM reasons for excluding it include (a) zero trees in sample for years 1400-1404; (b) just one tree in sample for 1404-1421; (c) just two trees in the sample for 1422-1447; (d) “the authors who originally sampled the Gaspe data don’t use any of the data before AD1600″. (Source: McKitrick’s “What is the hockey stick debate about?” presentation – link at top left, under “Favourite posts”.)

      I waded through Tamino’s post at RC, including the comment from Jean S. The tone of the article is that most of the data has a hockey stick shape, however you average it; it’s everywhere. Jean S suggested Tamino reconstruct the results minus both NOAMER PC1 and Gaspe, but suddenly Tamino flew into a rage which implied that Jean S would keep asking for one series after another to be removed until there was nothing left, what a waste of time etc. I guess we weren’t meant to realise that, contrary to the impression given by RC, simply excluding NOAMER PC1 and Gaspe (even for just 1400-1450) would immediately have a dramatic effect.

      Steve: it is untrue that “most” of the proxies have a HS shape. The Grybill bristlecones (Mann’s PC1) and Gaspe do. That’s why this was the sensitivity of actual interest. Tamino misrepresented the situation.

  8. pesadilla
    Posted Jul 27, 2010 at 5:30 PM | Permalink

    I know this is off topic but according to the new scientist, UEA are about to release three complete data sets in a pilot scheme.

  9. Luis Dias
    Posted Jul 27, 2010 at 7:13 PM | Permalink

    This is completely preposterous. I mean wow.

  10. Craig Loehle
    Posted Jul 27, 2010 at 8:02 PM | Permalink

    It is a curious combination: the Team treats the slightest mistake on critics’ (not even necessarily a sceptic) part with derision and ridicule (though they often attack a straw man) but they go on oblivious to their own mistakes. Or maybe that does make sense…

    • Tom Gray
      Posted Jul 28, 2010 at 7:09 AM | Permalink

      “Science” and to be more specific “peer review” are in some circles now taken to entail absolute certainty. Scientists are taken to be omniscient whose opinions cannot be doubted. Because of this, the Team cannot admit to any mistakes. If they admit to one mistake then they cease to be omniscient and their opinions are just like those of anyone else.

      Now suppose that one of their ciritcs makes a minor mistake. This can be taken as part of a mathematical proof. Their critic has made a mistake. Thus their critic is not omniscient. Therefore their critic is not a scientist whose opinion is the last word on any topic.

  11. Posted Jul 27, 2010 at 9:00 PM | Permalink

    Steve:

    Don’t know how you can post this, but the classic Elsasser 1942, “Infrared Radiation Heat Transfer in the Atm” is at:

    Page 23 is very interesting as Dr. Elsasser notes CO2, in the “Troposphere” to be an EQUAL upflux and downflux agent.

    Therefore his “General Radiation Chart” only accounts for WATER!

    Steve; please put this sort of comment on an Unthreaded thread,

  12. Boris
    Posted Jul 27, 2010 at 10:03 PM | Permalink

    Why does Monford call the 1400-1500 peak the “Medieval Warm Period” when it’s 200 years later?

    Steve: perhaps he’d been watching Inconvenient Truth, which did the same thing. The difference being that I’m sure that Andrew will correct the mistake if the book is re-printed.

    • GrantB
      Posted Jul 27, 2010 at 11:19 PM | Permalink

      Touché the bolded response

    • Nick
      Posted Jul 28, 2010 at 12:10 AM | Permalink

      Montford will have to do more than that,Steve. He’ll have to correct all the insinuations that are built on that misidentification….

    • Scott B.
      Posted Jul 28, 2010 at 6:19 AM | Permalink

      Are we even sure those peaks respresent temperature? Yes, the lines form peaks in the data that reach heights similar to the more contempory peaks. I think it seems reasonable, if we accept that these lines accurately reflect temperatures, to assign the 15th century peaks to the MWP, and the current peaks to modern warming.

      However, a better question might be why would a proxy show a peak temperature 200 years after the MWP? The answer might be a simple as because that proxy just doesn’t work.

      • ChrisZ
        Posted Jul 28, 2010 at 6:30 AM | Permalink

        Another answer might be that the peaks we see *ought to* correlate with the MWP, and their ascription to 15th century is wrong. I see little reason to view the x-axis of these graphs as any more reliable than the y-axis.

        BTW, misdating (x-axis scaling errors) alone might lead to a flattening out of the MWP and other past phenomena as more and more shakily dated proxies are added to the mix (even if every one of these IS a proxy in the proper sense of the word), because the individual peaks and troughs won’t be “in sync” with each other in the distant past, while they likely WILL be in sync in the present, thus neatly reinforcing each other at one end of the graph only, but partially cancelling each other out at the other end. Hey presto – a hockey stick….!

        • Hu McCulloch
          Posted Jul 28, 2010 at 7:40 AM | Permalink

          One virtue of tree rings is that they are well-dated. Dendrochronology is a precise science, even if dendroclimatology is not.

          Other proxies (with the exception of a few well-layered ice cores like Quelccaya) are much more uncertain in their dating. This is true of most of the series used in the Loehle-McCulloch reconstruction:

          (Craig did the reconstruction and I just provided the se’s. See http://www.econ.ohio-state.edu/jhm/AGW/Loehle/ for paper and details.)

          Our graph (whose time axis is by no means certain) shows the MWP peaking in the 9th and 10th c, with a rebound in the 13th and 14th c, but pretty much gone by the 15th c. It would be fair to say that Mann’s calculation (now disputed by Tamino) revealed a previously unsuspected Late Medieval Warm Period when the two series in question were removed.

        • Hu McCulloch
          Posted Jul 28, 2010 at 7:42 AM | Permalink

          Well, the graph didn’t imbed, but you can see it at the link provided.

    • Boris
      Posted Jul 28, 2010 at 8:32 AM | Permalink

      On a site where Michael Mann’s every tiny error is mocked and highlighted, I would expect you to at least note that Monford is quite wrong on this point. Instead you not only ignore it, but quote it approvingly.

      • Tom Gray
        Posted Jul 28, 2010 at 12:40 PM | Permalink

        Tiny?

        I thought that it was iconic and featured in IPCC reports, news conferences, feature movies etc. It was even used prominently in a pamphlet sent to every home in Canada by the Canadian government to prove AGW.

        So – Tiny?

      • Posted Jul 28, 2010 at 7:35 PM | Permalink

        Re: Boris (Jul 28 08:32), Steve replied to your original comment

        …I’m sure that Andrew will correct the mistake…

        Now you say

        I would expect you to at least note that Monford is quite wrong on this point. Instead you not only ignore it, but quote it approvingly.

        I hope this remark of yours was made before Steve’s reply to your earlier comment. Otherwise I would have to conclude that, in the common language, you are lying. Certainly when you say Michael Mann’s every tiny error is mocked and highlighted here, you are misleading. Mockery has never preceded highlighting here, and has only occurred as a last resort when reasonable requests for important data and corrections have been unreasonably refused and ignored; the level of mockery is highly subdued in comparison with RC. If you can point to any specific instances of mockery unwarranted by these conditions, I’m sure Steve would be perfectly willing to remove / correct / apologize – as always.

  13. stephen richards
    Posted Jul 28, 2010 at 2:48 AM | Permalink

    Nick and Boris

    Poodles bite the bishop. :)

  14. Ian B
    Posted Jul 28, 2010 at 2:58 AM | Permalink

    Regarding the concept of a joint paper, espcially when there are large areas of agreement on fact but differences of interpretation is a very sound one. Even now, several years after the initial Mann reconstructions, such a paper would be beneficial in helping to direct any further palaeo-reconstruction work. Is there any merit in pursuing with Briffa (for example, if he has sufficient knowledge of the statistical techniques used in the various Mann and subsequent reconstruction papers), as it would be good PR for CRU / UEA in light of the Muir Russell findings of a lack of transparency?

    As a parallel, I am professionally involved in civil Expert cases in a science/engineering field. Working under English law, such cases almost inevitably include a ‘without prejudice’ meeting between the Experts for both sides, which involves the production of a production of notes to be presented to the Court, to cover the following issues:
    1) Technical areas where the Experts are in agreement
    2) Technical areas where there is no agreement (or partial disagreement)
    3) Reasons why such disagreement exists – this may be based on different analytical findings or more commonly is a difference in interpretation or relative weighting of the facts.

    This approach offers a number of advantages, initially in fact checking but also in focussing discussion and potentially leading to a change of opinion if evidence from one side is sufficiently persuasive.

    We are currently also involved in a case in the Republic of Ireland, where no serious Experts meeting has occurred (officially one did, but it was a complete sham), and where the two sets of Experts are so far apart that they are continually talking past each other. I thnk there are a lot of similarities with the situation between CA and RC, or particularly between Steve and the ‘Hockey Team’.

    Steve: I agree entirely. In a business situation, there would have been a serious attempt to find out what facts are actually in dispute right at the beginning and what could be resolved. The tactic of the Team has been to avoid this. If I’d been in charge of the IPCC, knowing of this controversy, I’d have requested such a paper even if the and especially if the authors were at loggerheads.

    • Bernie
      Posted Jul 28, 2010 at 6:24 AM | Permalink

      Ian B:
      That is a very interesting procedural “invention”. Can you provide references to how this evolved and which other legal systems follow it? I had not heard of it used in the US, for example. It certainly sounds like it has elements that should interest bodies like the IPCC.

      • Ian B
        Posted Jul 28, 2010 at 7:32 AM | Permalink

        Bernie

        Not sure of the exact history, but I think it only became formalised in the last 15 years or so. You might find more information by googling Civil Prodecure Requirements 35.

        The contrast between the civility and calmness of the English system and the chaos of the Irish one has been very eye-opening, and has definitely highlighted to me the benefits of such a co-operative (rather than confrontational) system

  15. Posted Jul 28, 2010 at 3:16 AM | Permalink

    When I was at school, Medieval times ended with the fall of Constantinople in 1453.

    • Posted Jul 28, 2010 at 6:41 AM | Permalink

      Yup, I agree. And I went to school in Constantinople.

    • JamesG
      Posted Jul 28, 2010 at 7:44 AM | Permalink

      That being the case a 1000 year reconstruction is not of much value, especially when only the last 400 years is ‘plausible’.

    • KevinUk
      Posted Jul 28, 2010 at 10:50 AM | Permalink

      The good bish is indeed correct, at least according to this link

      http://www.britannia.com/history/medtime.html

  16. Posted Jul 28, 2010 at 4:47 AM | Permalink

    Steve,
    When I interviewed Ammann at NCAR in Boulder in August 2009, I asked him why he declined your offer. He said your condition was that he and Wahl dropped the two papers on which they were working. This was unacceptable for him, he told me.
    I suppose this is different way of saying ‘it’s bad for my career’ because you have convincingly shown how important the two Wahl and Ammann papers were for the hockey team and for AR4.
    Marcel

    Steve: My proposal was that we try to write a joint paper that superceded the attack-counterattack that was in the works. The armistice would apply to Ross and I as well. The objective was to supercede things that were in the works. If we did not achieve a joint paper that parties were satisfied within a finite short period, the parties could revert to existing hostilities. Ammann would then be free to resume work on the two papers. I think that it was an eminently fair proposal and that it should have been accepted.

    I sent the proposal twice in writing after our lunch meeting. Ammann did not reply to or acknowledge either email or make any counter-proposal.

    • DaveR
      Posted Jul 28, 2010 at 10:50 AM | Permalink

      Demanding Ammann drop papers? Now that’s something Steve hasn’t mentioned and it does put rather a different light on things.

      Steve: I described the offer very precisely at the time – see the contemporary account here http://climateaudit.org/2006/01/14/ammann-at-agu-the-answer/. This was a perfectly reasonable offer and should have been taken up. Ammann was not obligated to “drop” his submissions unless we were able to get a joint paper superceding them. The idea was that the joint paper would supercede the pending papers if we accomplished it. What’s wrong with that?

      Anyway, this gave me a really interesting idea. Rather than trying to hash out the rights and wrongs of who did what to whom, I tried a completely different tack. I pointed out to him that there was very little remaining community interest in more controversial articles on the same topic, which would undoubtedly leave the situation pretty much where it stands. However, I surmised that there would be very strong community interest in a joint article in which we summarized clearly:
      (1) the points of agreement;
      (2) the points of disagreement and
      (3) how these points of disagreement could be resolved.

      Because our algorithms were fully reconciled and almost identical to start with, I expressed optimism that we could identify many results on which we could express agreement. We could each write independent supplements to the joint text if we wished. If we were unable to get to an agreement on a text within a finite time (I suggested the end of February), we would revert back to the present position, with neither side having lost any advantage in the process. Pending this, both parties would put matters on hold both at journals and at blogs- and you’ll notice that I’ve been silent on this particular issue lately.

  17. ianl8888
    Posted Jul 28, 2010 at 5:45 AM | Permalink

    ” … and the ensuing migrations of the Turks into Asia Minor”

    migrations not – Genghis Khan had a go at what we now call Turkey and became so exasperated with various clans that just wouldn’t stop fighting him that he put them to enforced march east into the high plains desert for several thousand km (a truly dismal fate), basically saying: “Survive or not – see if I care !” A giant POW

    Many small villages in remoter parts of far west China (near the Siberian and Mongolian borders) now have shop fronts with four different languages – Chinese, a variation of Turkish, Russian and English. The small (for China) city of Hami is also known as “the city of the Moslem King”, which is quite extraordinary so far east and so close to the Russian/Mongolian borders. But the Khan knew why. Even several thousand km east into China, the locals identify themselves as “Kazakh”

    But I agree that this extraordinary twist of history needed a MWP to exist – one hard look at that high plains desert in winter tells you so. And the timing fits

    Steve- please do not debate MWP itself on this thread.

    • Posted Jul 28, 2010 at 7:36 AM | Permalink

      I have also been curious about whether there is a relationship between a more tepid climate and Mongol expansion across the Russian and Ukrainian steppes. I wonder if this issue has ever been subject of a scholarly research.

      We are getting OT (sorry, Steve) but several corrections must be issued to what’s been said above.

      1- The migration of Turkic tribes into Asia Minor pre-dates Mongol expansion by more than a century. See, Battle of Manzikert, 1071.
      2- Mongols never attempted to invade Asia Minor, but they invaded Georgia in the Caucasus, and later Baghdad in Mesopotamia.

      Incidentally, just tonight ABC in Oz began a documentary series of one man’s journey to re-trace Genghis Khan’s path. I missed the first part but it’d be interesting to see what he encountered climate-wise.

      http://www.smh.com.au/entertainment/tv-and-radio/the-trail-of-genghis-khan-wednesday-july-28-20100727-10tyh.html

  18. Posted Jul 28, 2010 at 5:58 AM | Permalink

    Isn’t it time we stopped attacking people like Mann and began showing a bit of sympathy? Whilst it would be hard to argue that climate “science” attracted top notch scientists and those who are there appear to more inspired by eco-politics than any dedication to the scientific method, we are where we are.

    People like Mann have built up the subject of global temperature investigation from virtually nothing to a mainstream subject. Whilst it is very easy to criticise them for their failures, it is easy to look back with hindsight and say that the data on which they based their findings was garbage, but perhaps that is a bit rich, because without people like mann there would be no data at all!

    The point is that this area wasn’t exactly equipped to become the focus of world-wide interest in the last few decades. They were totally under resourced, they lacked the academic high-fliers needed for a subject like this and they came under huge and relentless scrutiny when they were totally ill equipped to handle even internal scrutiny let alone external criticism.

    We’ve got to stop this relentless hounding of Mann. There’s no doubt he isn’t up to the job now, his findings simply don’t bear scrutiny, but let’s give him some slack – he did the best job he was capable at a time the world simply wasn’t prepared to put in the real resources it now appears obvious (with hindsight) that we should have had in place.

    What I’m saying, is lets stop looking at the past failures of climate “scientists”, and start trying to encourage those new universities and academics who will be entering the field and beginning to turn this from a “science” into science!

    • stephen richards
      Posted Jul 28, 2010 at 6:58 AM | Permalink

      Thats the biggest load of capitulatory rubbish I’ve ever read. The data existed even before Mann et al were born. That data had integrety, it had value. What Mann and the team have done through adjustment, manipulation and prevarication is to reduce the value of that data to nothing, nada, rien. These are not past failures as you say, these are past misdemeanours and no-one is hounding them. It was Grant Foster (alias Tamino) that decided to dig up the body of the long dead hockey stick NOT the Bishop and NOT Steve Mc.

      • Posted Jul 28, 2010 at 8:23 AM | Permalink

        Stephen, you are entirely correct. But we shouldn’t judge the “ancients” by modern standards. The data and much of the methodology was carp. But is it fair to criticise a subject that didn’t exactly shine in the academic stakes and was very much “left to its own devices” to invent its own (abysmal) standards and self-police, if this rogue subject when off on its own self-delusional track?

        When you are inside a failing discipline like this it really is very difficult to see how others see you. Like many other organisations suffering this kind of groupthink they invented a protective myth of the “evil sceptic”, and I would maintain that anyone but the really top notch academics with a lot of support from outside would almost certainly have fallen into their trap:

        – Bad temperature data
        – failure to admit they had bad temperature data,
        – fear that admitting they had bad data would undermine their assertions and lead to lack of funding.
        – so failure to secure enough funding to do the job properly
        – leading to cycle of trying to hide the abysmal state of the subject whilst seeing growing and growing hostility from outside, which only increased their fear of admitting how abysmal the resourcing of the subject and the ability of those involved was.

        The more the eco-alarmists like the WMF built up global warming “science”, the less able they were to do anything about their huge problems, because admitting they had problems would expose them to hostile scrutiny which they simply lacked the resources of academic credibility to deal with.

        Come on, any one watching the British Parliament Climategate inquiry couldn’t help thinking: “is this really the heart of this scam … a rather pathetic looking specimen with a department of three and a third rate vice chancellor who was so smarmy it made your skin creep”.

        It may just be that I was once on the “other side of the fence” and fully accepted the “scientific” basis of global warming, but I don’t think Mann is necessary “evil” or culpable for any wrong. He is wrong but as I said, I think many many other people would have been equally deluded as Mann in the same culture of groupthink.

        And if someone like Mann really did genuinely believe he was doing right, even if it later turns out he was totally deluded, is it right to keep criticising him for past mistakes?

        • stephen richards
          Posted Jul 29, 2010 at 2:56 PM | Permalink

          Who said the data was ‘carp’. Who made that judgement and on what grounds. All scientists know that data handling, collection, management and methods and equipment improve with time but that can never, never negate the ‘old data’. Data is data no matter what. If the method changes it may be possible to use that method ( not to adjust but to analyse) on the old data but not to manipulate beyond all recognition and without the specific metadato so that it can once again be tested.

          Data is the life blood. It is precious. It is vitally important that its’ integrity is maintained not matter what. You cannot just fiddle with it to your heart’s content. Sorry.

      • Boris
        Posted Jul 28, 2010 at 8:41 AM | Permalink

        “It was Grant Foster (alias Tamino) that decided to dig up the body of the long dead hockey stick NOT the Bishop and NOT Steve Mc.”

        Pop quiz: what was the title of Monford’s book?

        Next time, just stick to calling people “poodles” as it appears this is the limit of your useful contribution.

    • stephen richards
      Posted Jul 28, 2010 at 8:56 AM | Permalink

      I’m not erudite at all just an old scientist who has been enraged by the behaviour of extremely bad scientists and their defense league. I have and never will condone the misuse and abuse of data. Once data is gathered, validate, verified and tested THAT’S IT. The adjustment of that data at a much later date is, totally unacceptable in my eyes. I cannot and will not accept stupidity, scientific malfeasance, accidental adjustment or any other form of change as forgivable or acceptable. That data is fixed in time.

      If you don’t like it then as a scientist you go get your own. That is not the same as SteveMc who audits the work of these people and the cry from their defense league to go make his own charts with his own data, in this instance, is just baiting and a strawman to deflect critism.

    • Posted Jul 28, 2010 at 8:58 AM | Permalink

      Stacey, all subjects develop their own standards of “truth”. Experimental Physics can and has largely adopted the standards of real science. The result is that results in physics are exceptionally robust.

      That is however a luxury that cannot be afforded all subjects. A physicist can continue to repeat an experiment until they have proven beyond all reasonable doubt that the result is “beyond doubt”. If however. e.g. a medic were to continue to experiment of hundreds of thousands of animals just to prove that smoking is linked to cancer “beyond all reasonable doubt”, I think we’d all consider that standard to be too high.

      If however, you tried to achieve the same standards of proof in economic “science” then economic textbooks would be very short indeed. Is an economist who says there will be a double dip recession and turns out to be wrong any more “at fault” or even “evil” than Mann when he similarly used the same kind of lax-“science” procedures to come up with the idea that mankind was heating the globe?

      Physics works because it largely sets very high standards for proof. Economics, wouldn’t work if it tried to set the same standards. It only works because academics have developed a set of tools and techniques which seem to “provide answers” in a subject where facts and figures are much more nebulous.

      So where does climate “science” lie? There is only one earth, there are only 15 decades of world-wide temperature data and perhaps only a decade of anything close to acceptable for discerning changes smaller than 1C. Does that mean that this subject should just say nothing because there simply isn’t enough concrete data and only one experiment from which to gather data?

      We expect Economists to provide answers even though there is only one economy and it is constantly changing. Likewise we expect climate “scientists” to provide answers even though there is only one climate and the scale of accurate measurement is woefully small for meaningful results.

      I still maintain Mann was probably just trying to do his best to provide an answer to what was happening to the climate, he was doing it within the accepted standards of climate “science” and he was more than likely doing it to the best of his ability (even if he clearly wasn’t in hindsight up to the job).

      The real question is not why Mann made mistakes, but why when it is so painfully obvious that mistakes were made, that nothing at all seems to be done to ensure these mistakes never happen again!

      • Leonard Weinstein
        Posted Jul 28, 2010 at 12:28 PM | Permalink

        Mike,
        While what you have said is normally reasonable, the point you left out was how Mann and others supporting him responded when the possible errors and problems were pointed out, especially by Steve. They attacked him and any others with name calling, and implying that the skeptics were monsters. This when all the skeptics such as Steve asked for was data and information to allow them to check on the validity of something potentially important. It is hard not to say unkind things about people that are so unpleasant to you when you find they are wrong.

        • Salamano
          Posted Jul 28, 2010 at 3:29 PM | Permalink

          Are there other proxy reconstructions in the works that challenge those of Mann et al? With a similar or greater statistical reliability?

          Steve: My responses to Mannian squiggles has been to show that slight variations in proxy selection e.g. Polar Urals vs Yamal, Ababneh vs Graybill – yield different medieval modern relationships. I don’t claim that these are “right” – only that the field cannot progress without resolving such inconsistencies, as opposed to ignoring them.

        • Salamano
          Posted Jul 28, 2010 at 8:07 PM | Permalink

          And his response is that what you have just said is an ‘unhelpful’ suggestion because you are not volunteering to do that ‘resolving’ work?

          Or, that the ‘slight variations’ in proxy selection yield somewhat similar signals, such that the work of resolving those slight variations is essentially irrelevant because of the peculiarities involving use of proxy data in the first place, deemed a necessary evil?

          …or both?

          Steve – the slight variations lead to very different medieval-modern differentials. That’s why they prefer Yamal to Polar Urals. One version of Gaspe is dramatically different from another. It’s not that the differences in version are slight; its that the selection of Yamal vs Polar Urals or Ababneh vs Graybill should not lead to dramatic differences in result, but they do. There are many threads on this.

        • bmcburney
          Posted Jul 29, 2010 at 2:29 PM | Permalink

          But Steve, can’t we go beyond that? The “long” Gaspe is not just different, it is worse because the number of trees falls below standards. Yamal is worse than Polar Urals for the same reason. Graybill evidently favored strip bark trees so Abanneh is not just different but better (or throw them both out if the Graybill selection evidence seems insufficient). Mann’s use of Tiljander is upside-freaking-down. On the basis of neutral standards, not “choices” or attempts to determine the outcome, we should prefer reconstructions which use Polar Urals, Abanneh (or none), shorter Gaspe and we should not use Tiljander at all in the modern period. If proxy selection standards in each case are not flat out wrong, one should not choose the “team-favorite” proxies over the alternatives. If so, doesn’t that imply a particular outcome?

          Steve: Yep.

        • Craig Goodrich
          Posted Jul 29, 2010 at 2:43 PM | Permalink

          Dr Loehle did a no-dendro proxy temperature reconstruction, with the expected result — both the MWP and the LIA show up quite clearly.

          The paper is linked to on Jennifer Marohasy’s lovely and useful page at

          http://jennifermarohasy.com/blog/2008/09/ten-of-the-best-climate-research-papers-nine-peer-reviewed-a-note-from-cohenite/

          Steve: As I observed at the time, Craig’s reconstruction is much like the Moberg reconstruction. However, you should not be tempted to place extra reliance on it because you “like” the result.

        • Craig Loehle
          Posted Jul 30, 2010 at 9:35 AM | Permalink

          I agree with Steve about not preferring my study just because you “like” the result. My goal was to show what happens when you don’t use tree rings. I had insufficient data to get precision, and did not claim otherwise.

      • Dominic
        Posted Jul 29, 2010 at 8:35 AM | Permalink

        OT

    • stephen richards
      Posted Jul 28, 2010 at 9:00 AM | Permalink

      Thanks Stacey an old Physicist agrees. Although Rutherford was a difficult man when quantum mechanics theory came along he went out and investigated. Although I have to say, there was an awful lot of swearing and cursing by the old guard until their challenges were met. Thats how physics works and has always worked. It ensures that new theories are rigorously tested.

      That’s Real Science not the rubbish being espoused by the current AGW croud.

    • Steve Fitzpatrick
      Posted Jul 28, 2010 at 9:16 AM | Permalink

      “What I’m saying, is lets stop looking at the past failures of climate “scientists”, and start trying to encourage those new universities and academics who will be entering the field and beginning to turn this from a “science” into science!”

      Fair enough, any increase in rigor would be welcome. But there is the tiny issue of the existing petulant and unrepentant group, who will have to be involved in any evolution to a more rigorous science, still in place and still exercising considerable influence with governments (not to mention the peer reviewed literature). I suggest you look at the recent response of the Team to the publication of outright errors in the orientation of the data grid used in Mann et al 2005 and 2007 ( http://www.meteo.psu.edu/~mann/shared/articles/RMWAcomment_2010_jclim_smerdonetal.pdf ). To paraphrase, “How dare you point out substantive errors in our work without allowing us to gloss over these errors?” I sure hope JOC forces them to re-write this claptrap and stick to the substantive issues. Everything with them is personal.. one of the key characteristics of a pseudoscience.

      They are a very long way from behaving like rigorous scientists, and the Team itself strikes me as the principle impediment to reaching a reasonable level of rigor.

    • Posted Jul 28, 2010 at 10:15 AM | Permalink

      “He did not do the best he could if he fails to acknowledge and correct errors.”,

      Gerald, to be quite honest, I don’t think Mann is yet aware of the errors. Given our insight into the inner workings of this subject, it is quite apparent that they had built a “story” of their reality which everyone in the subject bought into and so they all really believe they are telling the truth.

      This is typical groupthink behaviour. The group shares beliefs and the individuals are strengthened in their beliefs because all the “us” believe them (and don’t forget to look in the mirror!). It is also characteristic of this kind of groupthink that anyone who questions the belief of the group is not only thought of as “them” but is actively categorised as being hostile to the group.

      This is where the myth of the evil fossil-fuel financed sceptic comes from. They have created this “bogey-man” to explain why us sceptics exist. Because, if they began to think that people who were sincere in their beliefs and knowledgeable about science could come to another view on the same evidence it would threaten their group “consensus”.

      I sincerely believe that Mann doesn’t think and act as he does knowing himself to be wrong. He may admit to himself to having “cut a few corners” because as he sees it, he didn’t have much choice given the lack of resources he had, but if this is as I’ve seen before – he really does believe he’s tried as hard as he can and he can’t understand the criticism!

      This kind of behaviour of groupthink occurs in many many places. It is particularly characteristic of poorly resourced, poorly led, high pressure environments working within a critical external environment. And, the more they are criticised, the less willing they are to expose their internal problems to open criticism, the less they accept external criticism and the more the group looks to other members of the group for support.

      The best way to change this kind of culture is to stop being over critical which simply entrenches those involved in the “hide the decline” mentality and to start praising those who do have the courage to openly discuss their problems and try to initiate solutions.

      Steve: please take this philosophisizing to an Unthreaded.

  19. Geoff Sherrington
    Posted Jul 28, 2010 at 5:59 AM | Permalink

    If this is not already noted, PJTV has this on 27 July 2010:

    http://www.pjtv.com/?cmd=mpg&mpid=105&load=3944

  20. Posted Jul 28, 2010 at 7:37 AM | Permalink

    You do great work Steve, but I feel sorry for you that you have to read that other blog !!!

    (time away from squash !!)

  21. stereo
    Posted Jul 28, 2010 at 7:46 AM | Permalink

    Reasonable people can disagree as to whether the post should be entitled “Mann Bites Dog” or “Dog Bites Mann”, but surely no one can dispute that They are The Gang That Can’t Shoot Straight.

    I am a very reasonable person, and I disagree with your juvenile attitude and your conclusions.


    In December 2005, as I’ve reported on many occasions, recognizing this point, I proposed to Caspar Ammann that we attempt to write a joint paper accurately setting down points of empirical agreement e.g. the results of 2 covariance PCS versus 5 covariance PCs; the impact of the presence/absence of bristlecones; verification r2’s, etc. Ammann refused, saying that this would be “bad for his career”. Whether or not it would have been bad for Ammann’s career, I think that the “community” would have benefited, if Ammann had accepted my proposal. (The offer was made in writing and including a proviso that the parties could go back to square one if they were unsuccessful in achieving a joint paper; it was a very fair offer.)

    Your overinflated sense of self importance just blew out again. I also see that you have continually made snide attacks and juvenile taunts such as

    Reasonable people can disagree as to whether the post should be entitled “Mann Bites Dog” or “Dog Bites Mann”, but surely no one can dispute that They are The Gang That Can’t Shoot Straight.

    and expect them to take up what is a very ‘fair’ offer of co-operation.

    As a very reasonable person, I think the post should be entitled, “McIntyre once again insists he is a very fair and reasonable person, while demonstrating that he isn’t.”

    • Stirling English
      Posted Jul 28, 2010 at 8:06 AM | Permalink

      People who are confident in what they do and open to debate and discussion are usually able to take a little gentle humour at their expense. And may indeed revel in it.

      Those who are insecure in their work and wish to avoid engagement do not. They must forever attack, since they have no defence.

    • Gerald Machnee
      Posted Jul 28, 2010 at 8:37 AM | Permalink

      Some (many) people have tried to be reasonable at RC and got censored.

    • PhilH
      Posted Jul 28, 2010 at 8:50 AM | Permalink

      I don’t know how long you have been reading this blog, but regular readers know that Steve has been the object of a hate campaign by the Team for many years. A campaign that has seen every kind of vituperation and slander one can imagine.

      Your comment, far from being “reasonable,” is simply ignorant. If you have something constructive to say about the scientific/statistical questions involved in this post, we would be glad to hear it.

    • Stacey
      Posted Jul 28, 2010 at 8:58 AM | Permalink

      I suggest you read the Climategate emails after reading then come back and tell us there is nothing wrong?

      As a reasonable person you will be unable not to be absolutely disgusted with the behaviour of these self promoting junkett scientists.

      • stereo
        Posted Jul 28, 2010 at 4:13 PM | Permalink

        I suggest you read the history of this blog. The constant harrassment, misrepresentations, school yard taunts and accusations have nothing to do with science.

        • Doug Badgero
          Posted Jul 28, 2010 at 6:10 PM | Permalink

          I suggest you read the blog itself instead of inventing a “history” in your head.

        • Michael
          Posted Jul 28, 2010 at 8:41 PM | Permalink

          Dear Stereo

          What is wrong or anti-science with accusations? The accusations are valid questioning of whether the scientists have acted ethically and professionally and go to the heart of the science, nothing wrong with that as it is backed up with evidence that on the face of it they have not.

          As a ‘very reasonable person’ you will understand that your perception of “constant harassment” is contrasted with my perception of Steve being constantly stonewalled and therefore your critism holds no weight; to me that is.

          What are the specific misrepresentations you believe that Steve has posted here on the blog?

          Michael

        • Posted Jul 29, 2010 at 10:25 AM | Permalink

          I suggest you read the history of [realclimate]. The constant harrassment, misrepresentations, school yard taunts and accusations have nothing to do with science.

          FTFY.

  22. geo
    Posted Jul 28, 2010 at 7:56 AM | Permalink

    I suppose it is rather a pity that Muir Russell didn’t ask Caspar just what he meant by it being “bad for his career” to co-write such a paper with you, Steve.

  23. Boris
    Posted Jul 28, 2010 at 8:37 AM | Permalink

    “If you left out just two of the proxy series – the Stahle and NOAMER PC1s – you got a completely different result.”

    Mann claims that NOAMER contains 70 proxies–true or not?

    Steve: there are 70 chronologies in the AD1400 step. The Graybill chronologies (and Linah Ababneh did not replicate Graybill’s Sheep Mt chronology – an important underconsidered issue) are 16 or so of the 70. They are more or less orthogonal to the others, which is why their distinct pattern survives as separate cluster in the PC4 using covariance PCA on dimensionless chronologies. If you exclude the Graybill chronologies – an exercise famously done in Mann’s CENSORED directory – you lose the stick shape in the NOAMER principal components. This sort of empirical point is agreed to by all parties. The difference lies in Mann’s insistence that there is some sort of “mathematical” law requiring the inclusion of the controversial bristtlecones. There isn’t.

    • stephen richards
      Posted Jul 28, 2010 at 9:01 AM | Permalink

      SO ! What’s your point?

    • Boris
      Posted Jul 28, 2010 at 12:12 PM | Permalink

      The point is to a layperson saying “only two series were excluded!!” sounds like one thing and saying 70+ proxies were deleted (or an entire continent!) sounds like another. So why are you are guys like Montford continually sexing up your claims? The actual issues get buried in the rhetoric.

      • David
        Posted Jul 28, 2010 at 2:16 PM | Permalink

        Boris,
        It is not sexing up any claim at all. The Graybill chronologies (thats 16 of Mann’s 70 btw – not 70 in their own right), all represent a single region (part of USA) and are done on a type of tree which several independent authorities have warned against using as climatic indicators, because there is very strong evidence their tree rings have a very poor if any relationship to temperature.

        On top of that, the Graybill chronologies do not actually correspond well at all with recorded temperatures in the region – as if to amplify the warnings from above.

        That these trees have some kind of magical quality to track global temperature but not local temperature, and that their exclusion along with the Gaspe series causes a strong MWP in the reconstruction should for any rational person set alarm bells ringing on Manns work. What is it about these 17 proxies which must somehow override the 50 or more others ? Mann’s complaint that the validation statistics are much better with them included, so they must therefore be included to make the study more rigourous is simply hysterically funny to anybody with a background in science. I simply cannot believe he can make such statements with straight face.

  24. Craig Bear
    Posted Jul 28, 2010 at 10:18 AM | Permalink

    Was directed @ sHx’s post…

  25. carol smith
    Posted Jul 28, 2010 at 1:54 PM | Permalink

    snip – please don’t try to debate the MWP in a few paragraphs

  26. Salamano
    Posted Jul 28, 2010 at 2:59 PM | Permalink

    I think a recently posted comment by Gavin at RC is a pretty useful one…

    Paleo-reconstructions are not anything special in science – they are simply the result of lots of people trying to see what they can discern of the past through a rather murky lens. Your ‘auditors’ have decided that any judgement call in doing that must be challenged and insinuate continuously that every issue is being fixed for some ulterior motive. This is not a useful challenge to the science, because it undermines the making of any judgement in the analysis whatsoever. The ‘auditors’ do not produce alternatives because they too would have to make decisions about how to proceed which would open them up to their own criticisms. That is what needs to change if they are going to make a contribution. For an example of how that ‘citizen science’ can really work, look at what Ron Broberg and Zeke Hausfeather are doing with the weather station data – they aren’t sitting around declaring that ‘it can’t be done’ or that the GISTEMP/CRU/NCDC methods are fixed, they are going into the data, making choices, seeing what impact they have and determining what is robust. Indeed, that is science without the need for the quotes. Would that there would be more of that.

    I do think that citizen auditors are useful, and have been useful in furthering the process and evolution of reconstruction understandings toward ones of more confidence, and not less. I would furthermore assert that it’s because of blogs like these that revisions, addendums, supplements, and what-have-you get sped out for consumption (whether it’s to correct misinformation or not).

    I think Gavin has indirectly admitted as much, and has also acquiesced to the idea that nascent reconstructions are not as good as the more recent ones (which would be obvious), and that comments and criticisms of them– that did not necessarily happen in the ‘peer review, but rather the ‘citizen audit’ have essentially fostered the additional information that followed papers like MBH98.

    I do think he has a point, though, in some respects. Essentially there is one group of people running this gauntlet of multiple reviews and audits, and it’s probably tiresome considering there’s little else from others as far as contributing to the pool things to be criticized. (What I’m speaking about here, is where are the alternate reconstructions of ‘similar statistical validation’?)

    I don’t think it’s necessarily fair to say that there can’t be any possible ‘good’ proxy temperature reconstruction, and therefore assert we’ll never know with confidence how temperatures have changed over time. There certainly seems to be ‘something’ redeemable within these proxies. Reliable temperature reconstruction back as far as we can go (especially through the MWP) is something that has a pressing need.

    If all agree it is possible, then where are the papers for the alternatives..? It certainly would be sinister to reject publication of them if they fail the same sort of rigors pointed out by citizen auditors for papers that have passed in the past, unless it is agreed that the citizen auditors (and not the peer review) provided the insight.

    But do they exist? Have they been refused publication? Or, do all who attempt such a thing to come up with a reliable proxy end up with similar results to Mann?

    • Carl Gullans
      Posted Jul 28, 2010 at 9:13 PM | Permalink

      What a bizzare statement, coming from Gavin. First of all, “going into the data, making choices, seeing what impact they have and determining what is robust” hasn’t been possible with most Team papers because the data and methodologies have been kept hidden by the very people he is defending. This is a chronic and strong complaint at CA.

      Secondly, has Gavin ever heard Steve suggesting that “if such and such group of proxies was used instead of this other one, the result completely changes”? Isn’t that pretty much exactly what CA has spent a large amount of its time arguing for years?

      Thirdly, if I may purposely be silly to demonstrate a point: if a group of scientists are claiming that they have demonstrated with some evidence that cheese can be turned into gold, and then one points out that the cheese—->gold conclusion was reached using erroneous methods, one is certainly not obligated to submit an alternate formula for cheese —> gold. Scratching the notion that such a thing has been established from the scientific record is indeed “Science”; Science only existing to further hypotheses, never being allowed to tear them down, is quite an odd belief.

      And fourth of all, using statistically incorrect methodologies isn’t “judgment”, it is “wrong”. Some complaints about the Team corpus are judgment calls, but many/most relate to bad mathematics. None of these points are ever addressed or conceded, because doing so would be terrible for Science I suppose…?

      • Steve McIntyre
        Posted Jul 28, 2010 at 9:41 PM | Permalink

        “going into the data, making choices, seeing what impact they have and determining what is robust”

        Surely that is precisely what Ross and I did in our analyses of MBH.

        The problem with the “proxies” is that they are inconsistent. My recommendation to practitioners has been to try to reconcile all the apparently conflicting results in individual regions.

        If I believed that you could make a useful reconstruction from these materials without being subject to the criticisms that I make against others, I would have done so. But I don’t think it’s possible.

        If the scientists in question are making inflated and incorrect claims about their work, I see no reason why that shouldn’t be pointed out. Not making incorrect and inflated claims is always available to them.

        • geo
          Posted Jul 28, 2010 at 10:20 PM | Permalink

          Yes. Counter-attacking someone’s critique of your perpetual motion machine by sneering that they have not yet offered their own perpetual motion machine is hardly a convincing rebuttal.

    • AMac
      Posted Jul 28, 2010 at 10:17 PM | Permalink

      Re: Salamano (Jul 28 14:59),

      I don’t think it’s necessarily fair to say that there can’t be any possible ‘good’ proxy temperature reconstruction, and therefore assert we’ll never know with confidence how temperatures have changed over time.

      How about this statement:

      There can’t be any possible good proxy temperature reconstruction that is based on the calibration of uncalibratable data series to the instrumental temperature record.

      Mann08’s methods require the calibration of proxy series to the instrumental record.

      The Tiljander proxies cannot be calibrated.

      Mann08 employs the Tiljander proxies.

      It is therefore necessarily fair to say that Mann08’s temperature reconstruction methods and conclusions cannot be considered to be good.

      A set of sentences that are simple. Logical. Sequential. Contrast with Gavin’s and others’ sophistry and evasions on this point, at Gavin’s Collide-a-scape thread and elsewhere.

      “Who’re you gonna believe, me or your lyin’ eyes?”

      • stephen richards
        Posted Jul 29, 2010 at 3:02 PM | Permalink

        Mann used Tijander upside down!!

  27. Salamano
    Posted Jul 28, 2010 at 3:02 PM | Permalink

    Hmm…it seems like some of these posts can get posted out-of-order…

    I posted mine at 2:59 PM …but it is followed by a post that was made at 5:45am

    Steve: if you install the Greasemonkey feature CA Assistant (highly recommended), you get things in chron order, rather than thread order.

  28. Laws of Nature
    Posted Jul 28, 2010 at 4:56 PM | Permalink

    Dear Steve,

    in an older post:

    http://climateaudit.org/2007/10/12/a-little-secret/

    you reported on the result of one bristlecone tree ring width and said, that you would publish the results of your proxi updating tour. Did you do that? How do the other trees look like?
    (I thought I remember seeing more of these curves here . . probably in an excel-file or so, but couldn’t find it)

    Thanks a lot,
    Laws of Nature

    P.S.: Over at RC in the answer to JC, did Gavin really point to a graph made by M. Mann (S8), showing, that you loose all information about the time before 1500 when you remove the bristlecones and 7 more proxies?
    I am just wondering, since these 7 proxies are obviously not used in MBH98.. :)

    Steve: I published a series of posts here, placed the measurements online and presented at an AGU poster session, but haven’t submitted to a journal. I need to clone myself.

    • scientist
      Posted Jul 29, 2010 at 2:36 AM | Permalink

      1. Links please?

      2. Were all the collected tree samples, finally measured and disclosed?

      3. The series of posts, the poster and the excel…do all of these things contain all the missing samples or were they distributed amongst them?

      4. Is (all) the data archived at the tree ring database?

      • MrPete
        Posted Jul 29, 2010 at 7:19 AM | Permalink

        Re: scientist (Jul 29 02:36),
        My perspective…last I knew,
        1) All the data has been available online here for a long time: http://www.climateaudit.info/data/colorado/ Metadata for 100% of the samples collected is included, even the earliest “trial runs.” And including our cross-correlation decode of the various sample ID / Tree ID / tagging codes.

        2) The remaining samples did not crossdate. We hope to provide that info online as well; perhaps the community can work on solving the dating puzzles :). Doing so is a time-and-resource challenge (any examples of systems for useful online presentation of microphotographed tree ring cores?) Everyone’s been engaged with other things.

        3) What do you mean by “missing samples”?

        4) As has been noted, this isn’t about creating new proxies. And we’ve been told in no uncertain terms that journal publication of a dataset is not going to happen. The data is available. If it would be helpful to also archive at ITRDB, that can certainly happen.

        • scientist1
          Posted Jul 29, 2010 at 12:33 PM | Permalink

          Sounds like a screwed up expedition. Dano warned you of the likelihood that you would want to go back and resample…but you still did not sample adequately. (Nor go back and resample.)

          I’d like to see a full post-mortem. You all led and bled with this thing. Promised to finish it off…then never wrote it up (even as a post). Given the level of care, I’m actually kind of concerned about the sampling technique (getting good cross sections and all that).

          How many samples did you get per tree? How many were you unable to cross-date? Why? How does this correspond to expectations? Did the prevalence of uncrossdateable samples lead you to have too few samples to make good analyses?

          And just post the measurement series. Why do you need to post the pictures? Or was it that you just couldn’t resolve the rings? Sure, show a few pictures…maybe not for people to date them, but there could be other insights, like poor borer operation, or not getting a cross-section or some other technical issues related to sample extraction. (I hope to heck, that you read up and got up to speed on sample extraction, but am very open to the possibility that you did not, and that it hurt your Starbucks publicity stunt.)

          Ok…if you can’t publish it in a journal, write it up like a paper and post it here. Do some ANALYSIS. Look at it like a business problem. How many samples were un-dateable? I don’t even know if this is 50% or 80% or 2%. What are the tree to tree lessons? What is the overall series story? How does it match or differ with other previous related work?

          Oh…and you joked about how the places weren’t remote, but you busted the car up…;)

          Oh…and the correct answer is “no” (didn’t archive the info). So go do it! This whole thing was supposed to be a chance to show how easy it is to do “textbook” work. Well…do it! Right now, your complaints of other not archiving seem a little hypocritical.

          Steve: The measurements were placed online as soon as I got them and are online today. Your statement that there were no posts is untrue. There are numerous posts and a poster was presented at AGU. Anyone who wants to use the Almagre measurements can access them. The purpose was to show that it was easy to obtain updated samples. It was. The roads were a little rough, but would have been easy to navigate with a 4-wheeler or ATV. It was EASY to get to. It was difficult to locate the Graybill sampling area, because this information had not been documented. The measurements were uploaded at the time and presented at AGU. The samples have also been used for del-O18 tests.

        • scientist1
          Posted Jul 29, 2010 at 12:54 PM | Permalink

          Did the study you did correspond with Graybill or Ababneh? Or something else entirely? How so and to what extent and in what way? Or were there too few samples to tell anything (in which case something about effective expeditions is learned)? I honestly have no clue what the result of the test was.

          Please link the AGU presentation.

          Steve: the number of samples was comparable to Graybill’s expedition. An updated chronology didn’t show ring widths going into the stratosphere as would be “expected” if ring widths were to continue getting larger with warmer temperatures. Go to http://www.climateaudit.info/pdf/ and look for agu07.

          Graybill is dead. Pete Holzmann met with a person at LTRR, but the fatwa against Climate Audit required some confidentiality. Ababneh refused to provide information. However a friend of hers contacted me and said that my discussion of her work was fair and noted the obvious difficulties for her that resulted from her work contradicting the powers that be.

        • scientist1
          Posted Jul 29, 2010 at 5:35 PM | Permalink

          We’re segueing, but if Ababneh differs from previous bcp work, that seems like a different type of result than what happened with your resampling project. You say in your poster that your resample chronology matched the previous one ‘well’ (not quantified).

        • scientist1
          Posted Jul 29, 2010 at 5:38 PM | Permalink

          We were promised more in terms of a wrapup from those 2007 posts and never got it. Also more data to come. If you’re referring back to the 2007 posts then, that’s just…weird or evasive.

          Putting stuff online is NOT the same as archiving it. With all your agitation for responsible archiving, you did not use the central repository?

          Also, we were promised more data to come. It sounds like that never came. So a frank comment to that effect would have been helpful rathe than a 3 year wait.

          (The whole thing seems so…Thompson. You’re aping your enemies bad habits! Instead of that…show them how it’s done right!)

        • scientist1
          Posted Jul 29, 2010 at 12:44 PM | Permalink

          OK. I looked at the files.
          -Lot of detail in the excel file. Should be summarized with analyses.
          -Could not read the doc.kml in the .kmz folder.
          -last update seems to be from November 2007. If the rest of the samples were not cross-dateable, and that is the end of the study, fine. But we were promised a finish. It’s ok that some samples failed…but we should still have gotten a clear “we’re done now”. Since we waited for 3 years instead.
          -Needs to be written up. Even just as a blog post. If you are going to lead with all those Starbucks pictues and all that, it’s incumbent on you.

        • MrPete
          Posted Jul 29, 2010 at 2:18 PM | Permalink

          Re: scientist1 (Jul 29 12:44),
          – kml/kmz files are used in Google Earth. If you don’t have that installed, it won’t open.
          – We should do a writeup on the realities of archiving and cross-dating. I’ve made two visits to LTRR in Arizona, and have photos to show some of the real-world challenges involved.
          – You’re right that we “owe” a more complete finish. Unfortunately, one of the downsides of this being a 100% volunteer effort is that progress is made in whatever supposedly-spare-time is available. And there’s not much of that.

          – the REAL result of the test:
          – we successfully arranged a sampling expedition, including equipment, permits, etc on short notice and no budget
          – with no knowledge of actual BCP locations, we were able to obtain a good set of useful samples in one day
          – we returned a few more times and successfully discovered the “correct” trees, again based on incorrect information
          – we were able to obtain a large set of useful samples and associated metadata, and even matched them to prior collected data, all without the help of useful metadata from the earlier work

          The actual data that resulted is in some ways immaterial. Our goal was to prove the Starbucks Hypothesis. Anything beyond that is gravy. HOWEVER, I agree with you that we should finish this up.

          There is value in extracting whatever knowledge can be had from the work done and data collected.

          Some further answers to the prior questions:
          – Why post pictures: sadly, some dendro’s don’t bother with manual crossdating of material that can’t be auto-dated. Best practice however is to go back to the collected samples. To do so requires seeing the samples — ie a picture.

          – Access difficulty: once we knew where the “real” BCP’s were, reaching them became quite easy. They are not far from a well-marked, highly used forest road. If that information had been available, we would have saved much time and some car repairs :)

          (Most of the other questions are answered in the data…)

        • scientist1
          Posted Jul 29, 2010 at 4:40 PM | Permalink

          Thanks Pete.

          The poster is a decent poster, as a poster. It is inadequate to summarize the study though. Even of the cores that you did collect. Also, this was definitely billed as “more to come” in the posts at the time in CA (and I suspect those are the same “series of posts” Steve refers to, which are also an inadequate wrapup. If we’re never going to get the undateable samples, fine. But write up what you have (with numerical analysis, numerical comparison to previous work, quantification of the amount of “divergence” etc.)

          Also if the stuff is not in ITRDB, that is totally unsat.

        • scientist1
          Posted Jul 29, 2010 at 4:55 PM | Permalink

          If the main purpose of the test was to validate that proxies can be updated, I’m not convinced. Certainly, I haven’t seen textbook, updating of series from you all (new info not archived, not quantitatively compared to previous work, didn’t find all the trees (not nesc your fault, but that;s not the point per se).

          Furthermore, this is a single test. Some campaign to update the proxies can’t be evaluated in difficulty form a single expedition.

          And really, there’s no scope to what you want done. You can say that it’s a bunch of work to scope that out, but really how can you argue that it should be done and can easily be done, if you can’t desrcibe how much needs to be done? How many trees, how many areas, budget, time, etc. Treat it like any business or technical project.

          —————

          Furthermore, it’s not clear to me if you are trying to get exactly the trees that were done before. I think in some cases this will be impossible (location lost, tree burned down, land ownership changed, etc.) Really you ought to be collecting BOTH the same identical trees that were done before AND other trees nearby (with specification ahead of time, of the sampling method you will use…ie. what sorts of microlocations). Then if the new trees closely match the old trees (as reported), you can trust their updating of the series.

          If they don’t, that’s a story in and of itself! (That resampling, even just of the population, forget later date, gives a different story. Gotta figure out why.) And I pointed this out to you guys a while ago. Didn’t need Ababneh for that idea. This is just fundamental scientific intuition that you should have for any problem in science, engineering, economics or business.

        • scientist1
          Posted Jul 29, 2010 at 5:26 PM | Permalink

          I’m also curious why the results can not be published as a short note? Was it because the study was too small, lacked non-trivial results, or had too many errors in collection?

          Did you think ahead of time about what is publishable and what not? Did you have a feel for it at the time? Do you even know, really have a sophisticated perspective on this question?

          What about this journal:

          http://www.treeringsociety.org/journal.html

          Did you ask there? I would be really surprised if they are rejecting a lot of papers. Seems like if you cut the Starbucks and the incrowd snark, and reported what you found, that they would take it. And it would force you to finish your work, even analytically yourselves.

          -describe the aims of the expidition (skip Starbucks and knobby knees) as a replication and update.
          -Describe and quantify how much you were able to replicate.
          -quantify the match of the new data series to the old one (both tree to tree and overall)
          -share the updated (new years RW) and quantify the extent of recent slowdown (it seems to me that, the recent years are definitely above mean, but I guess you are arguing they are below mid century).
          -calibrate versus local temperatures and describe the correlation (bothe mid century and more recnetly). Run the test and see what the numbers show you.
          -make tactical and strategic suggestions for other work to update more series (don’t over-reach and be fair.) I would go easy here. Earn your stripes first, by reporting this representative updating. Certainly record the basic idea that more updating could be done, since it is interesting to the reader and belongs in a conclusion…but I would save a big article on “scope of needed tree ring updating” for a separate one. But could go in same journal at a later date. If you treat the problem seriously and do substantial honest work on scoping the problem, I’m sure you can get that published (not CA blog post leve of work…that’s insufficent…more like what a good analyst does for a business proposal).
          -describe and quantify the issue of non-dateability. It’s not clear to me if this is valid RW, but numbers don’t wigglematch or that you can’t even find the rings? Show a couple (representative!) pictures of the non-dateable cores. [doing this is valuable as perhaps others can suggest solutions or perhaps it casts light on your sample collecting or for that matter perhaps there is a literature on "hard to date cores" and you are another brick in the wall and someone else figures out the issue later.]

          If you did all of the above, it would surprise me that you can’t publish. Possible, but I’d bet against it. Still worthwhile, even as a white paper, including all of the above. But I bet it’s plenty publishable. Read Klotzenbach (NASA) for the benefits of publication and arguments for why flawed experiments should be written up (with full notification of the limitations…honesty here can be disengaging…if you dropped the sample and lost it…ADMIT IT…don’t use a bunch of Mannian double-talk or evasions.)

        • MrPete
          Posted Jul 29, 2010 at 6:21 PM | Permalink

          Re: MrPete (Jul 29 14:18),
          Thanks for the encouragement. Hopefully we can get there. My “real world” life is way too full to do anything about it for a while. (Right now I’m trying to sustain my family and business through the current economic times… and hopefully make a bit of real progress on my life work at the same time…)

          We’ve been pretty careful to limit our expectations, be accurate w/ data collection etc. (My wife is a field biology person… it probably shows a bit in the metadata collection :) )

          Our real goal was to collect samples of any kind. Given that we had no information about the “original” trees, the idea of resampling said trees was a pipe dream. All we had to go on was two ancient photographs. On the third outing, one photo of a general area was matched… which unfortunately was a distraction (the “real trees” were nowhere near that photo site.) It was not until the fourth day, when we had already begun to find promising tree-tags, that we discovered a match for the second photo.

          When I get a chance, I’ll put together a blog post about metadata associated with older tree ring samples. The state of the metadata is…minimal… to put it nicely. Nobody was thinking climate back then. This multiplies the difficulty of directly replicating measurements on the same set of trees.

          Two caveats about limited expectations:

          1) Please remember, this whole adventure was not originally intended to demonstrate ability to do a full update of the proxy data. It was a response to a scientist’s claim that it is ridiculously costly to do the field work aspect of updating. The fact that we amateurs got something even mildly useful out of the exercise is amazing.

          2) If nothing else, the LTRR very much appreciated our metadata that applies to Graybill’s data. You see, they didn’t have anything useful in that regard. He was notorious for not keeping records.

        • scientist1
          Posted Jul 29, 2010 at 6:49 PM | Permalink

          Fair enough, Pete, you have a good heart and tone. Good luck with the dineros and bambinos.

          Most of my points remain (and adress your recent comment). Will not restate.

        • RomanM
          Posted Jul 29, 2010 at 8:52 PM | Permalink

          I can reaffirm Mr. Pete’s take of the whole affair. Apart from the possible archiving of the data, I don’t see any benefit for any of us here in pursuing further analysis of the tree ring series. There are more current issues of interest to be dealt with. However, if you wish to write a paper with it, I am sure that Steve will be more than happy to help you get started. ;)

          I might add that the whole exercise served as a great learning experience for myself (and possibly for some others) in fleshing out the details and the vagaries of tree rings with regard to their collection and processing besides being fun entertainment.

    • Posted Jul 29, 2010 at 3:14 AM | Permalink

      Re: Laws of Nature (Jul 28 16:56),
      I think you both may be missing the point. The aim of Steve’s little expedition was not to produce a new and valuable tree-ring dataset from which to create a new temperature reconstruction. It was to show that the excuse that getting new data was costly and difficult was completely bogus. See also his 9.41 comment above:
      If I believed that you could make a useful reconstruction from these materials without being subject to the criticisms that I make against others, I would have done so. But I don’t think it’s possible.”
      This is the key point of this post. Exactly which samples were used in which graph is a minor detail. The main conclusion to be drawn from the two graphs shown at the top of this post is that no conclusions can be drawn from this data. End of story.

      • Laws of Nature
        Posted Jul 29, 2010 at 4:01 AM | Permalink

        Dear PaulM,
        honestly, did you remember that Steve did that trip? I would say “perhaps”!?
        And like me, you might have seen the data, but apparently you cannot give a link to them.
        Had the trip any consequence to anyone beside a few people here? I don’t think so . . unless the data get published!
        I think that field trip Steve did showed something important, but this is not widely acknowledged .. however I also do believe Steve, when he says he was too busy . . his blog gives a nice testimonial to that . . I am not sure if also you others feeled that gap when he ‘dared’ to take some weeks of vacation . . :)

        • MrPete
          Posted Jul 29, 2010 at 9:20 AM | Permalink

          Re: Laws of Nature (Jul 29 04:01),
          If you click on the “Categories” popup at the top-left of any page on this site, you’ll find a category called “Almagre” under proxies.

          Those postings contain extensive description of the entire adventure, including links.

          There’s only one additional thing needed, which is a general aspect for this entire site: all the old data links throughout the site were broken when we moved to WordPress.com (a necessary result of the Climategate events.) Any link that used to say something like http://www.climateaudit.org/data/* etc… can now be found at the exact same address but substituting climateaudit.info for climateaudit.org .

          It’s all there, it’s easily found, the links repeatedly provided.

        • stephen richards
          Posted Jul 29, 2010 at 3:08 PM | Permalink

          I remember this expedition in great detail, no problem. The coffee, trial, the trees and Mr Pete’s and SteveMc’s nobbly knees. Fixed forever in my memory.

  29. Steve McIntyre
    Posted Jul 28, 2010 at 9:48 PM | Permalink

    I think that this post conclusively showed that Tamino totally misrepresented Montford in the calculations criticized here. I haven’t noticed a single concession on this point by a person who supported Tamino. (Nor obviously by Tamino or Gavin.)

  30. Al Tekhasski
    Posted Jul 29, 2010 at 12:46 AM | Permalink

    Any old Physicist (like myself) gets completely devastated after reading an introduction into “dendroclimatology”,

    http://www.cru.uea.ac.uk/cru/people/briffa/bradley1999_chapter10.pdf

    What a load of completely subjective baloney, I am really sorry for this “science”.

    • Peter Miller
      Posted Jul 29, 2010 at 2:49 PM | Permalink

      As a private sector geologist, I was fascinated by this document – I thank you for introducing it to me. In comparison, it makes homeopathy and scientology seem like real acience.

      Dendroclimatology may be OK for identifying the age of wood from certain ages in the past, especially catastrophic events, but that is where it ends.

      I have never read a document with so many caveats – this should be compulsory reading for all Mann/Jones/Hansen friendly politicians – with the caveat that a real scienrist then sits down with them and explains why it is at best irrelevant and at worst [snip] science.

    • stephen richards
      Posted Jul 29, 2010 at 3:09 PM | Permalink

      This old physicist agrees. Hu’s comment above rather took me by surprise when he said Dendrology was accurate. It is nothing of the sort by their own admission.

  31. stereo
    Posted Jul 29, 2010 at 3:25 AM | Permalink

    Mann08′s methods require the calibration of proxy series to the instrumental record.

    The Tiljander proxies cannot be calibrated.

    Mann08 employs the Tiljander proxies.

    It is therefore necessarily fair to say that Mann08′s temperature reconstruction methods and conclusions cannot be considered to be good.

    Mann’s statistical methods take care of that.

    • sleeper
      Posted Jul 29, 2010 at 5:14 AM | Permalink

      Take care of what? What statistical method allows one to calibrate a proxy that has no physical relationship to temperature in the calibration period? Please enlighten us.

      • RomanM
        Posted Jul 29, 2010 at 5:40 AM | Permalink

        It’s easy! All you have to do is make the right “choices”… ;)

    • AMac
      Posted Jul 29, 2010 at 5:52 AM | Permalink

      Re: stereo (Jul 29 03:25),

      Mann’s statistical methods take care of that.

      If Mann08’s authors and champions believe that their statistical methods take care of that, they should move the discussion forward by so stating.

      Stereo, I hope you submit your succinct observation to Tamino’s thread at RealClimate (Tiljander is covered in “Hockey Stick Illusion” on pages 367-370 and 373). It is sure to pass moderation and prompt an insightful inline response.

  32. stereo
    Posted Jul 29, 2010 at 4:01 AM | Permalink

    If the scientists in question are making inflated and incorrect claims about their work, I see no reason why that shouldn’t be pointed out. Not making incorrect and inflated claims is always available to them.

    says the great nitpicker. A typical one would be the claim that Manns methods always pick a hockey stick out of red noise. You didn’t mention that the ‘hockey stick’ was an order of magnitude smaller than the actual hockey stick.

    Steve: your statement here is completely false. The amplitude of Mann’s NOAMER PC1 as it emerged from Mannian PCA was entirely comparable to the amplitude of synthetic PC1s from red noise. In downstream regression operations, the PC1 was re-scaled and used as input to regression to give a reconstruction. A reconstruction using synthetic PCs was entirely comparable to Mannian reconstruction, a point made both at CA and in our 2005 articles

    • ianl8888
      Posted Jul 29, 2010 at 4:14 AM | Permalink

      Being able to extract a hockey stick of any magnitude from red noise is quite a mannian achievement

      Back to mono

    • Tom Gray
      Posted Jul 29, 2010 at 8:00 AM | Permalink

      Gavin has recently made such a comment on RealClimate about red noise hockey stickes being orders of magnitude smaller than proxy hockey sticks.

      Steve: Pure disinformation. Gavin doesn’t know what he’s talking about. Synthetic PC1 versus NOAMER PC1; reconstruction using synthetic PC1 versus reconstruction using NOAMER PC1 – are apples and apples.

    • PaulM
      Posted Jul 29, 2010 at 9:13 AM | Permalink

      Re: stereo (Jul 29 04:01),
      See Gavins comment #72 on Montford thread. Gavin is probably looking at Fig 1 of M&M 2005 where the upper panel (noise) has a step up of about 0.06, while the lower panel (MBH) has a step of about 0.4. Perhaps Steve could comment on this?

      Steve: The amplitude of the synthetic PC1s and Mannian NOAMER PC1 are very similar. When both are re-scaled and placed into Mannian regression, both yield similar reconstructions. In retrospect, a figure with two more panels would have made the point in pablum-sized bits. However, Gavin is throwing disinformation here – disinformation that even Wahl and Ammann did not descend to.

  33. Bernie
    Posted Jul 29, 2010 at 7:35 AM | Permalink

    It just occurred to me that while Tamino is attempting to rewrite the history of the HS and the validity of proxies, the real impact of the work of Steve, Ross and others has been in dramatically raising the expectations and standards around paleoclimatology and dendrochronology to an extent such that researchers are far more careful in what they pull together and try to publish. One can almost hear the discussion between the authors – “Will it pass McIntyre’s scrutiny?”

    Now that my friends is the real power of the peer review process!!

    • HaroldW
      Posted Jul 29, 2010 at 9:34 AM | Permalink

      Bernie (Jul 29, 2010 at 7:35 AM),
      Yes, that is exactly so. In AR4, the confidence attached to the hockey stick graph, as strongly as that was promoted earlier, was reduced, and it wouldn’t be surprising to see further backing away from it in AR5.

      The fact is that previously (pre-MM) there was not much, if any, critical scrutiny about such reconstructions. As a result, statistical rigor was low. At this point, the field has been well-informed about many ways in which various methods can create misleading results and statistical metrics (such as RE), and that is all to the good.

      I remain unconvinced that it’s possible at the present time to reduce the error bars associated with sampling, data selection, and reconstruction, to the point where we can make firm quantitative comparisons between the medieval and modern warm periods. There are too many confounding factors. But I wish the paleoclimatologists well in their efforts, provided that they will approach the subject with appropriate objectivity and awareness of the many statistical pitfalls which lurk. As you say, it is the efforts of statisticians such as Steve, Ross, Jean S, etc. who have alerted the field to the justifiable caution which must be exercised. And that is their true legacy, far more than the specific debate about the hockey stick.

  34. stereo
    Posted Jul 29, 2010 at 8:39 AM | Permalink

    Steve: your statement here is completely false. The amplitude of Mann’s NOAMER PC1 as it emerged from Mannian PCA was entirely comparable to the amplitude of synthetic PC1s from red noise. In downstream regression operations, the PC1 was re-scaled and used as input to regression to give a reconstruction. A reconstruction using synthetic PCs was entirely comparable to Mannian reconstruction, a point made both at CA and in our 2005 articles

    I seem to have a different understanding of PCA to you. The PCs are not the individual proxies, but the influences of the environment on the proxies that make them grow differently. The collective proxies reveal the underlying PCs, one of which is going to be temperature.

    • Bernie
      Posted Jul 29, 2010 at 9:30 AM | Permalink

      Stereo:
      You cannot assume that on an a priori basis. The problem is that the PCs may simply capture nothing that is interpretable, the random agreement of a subset of proxies, or as you say common factors influencing width and density of the tree rings. You cannot tell until you carefully look at the PCs and how various proxies show up in those PCs.

      Steve: Quite so. The Graybill bristlecone chronologies remain a separate “cluster” which is why they remain a distinct form even as a PC4 in centered calculations. Being a distinct pattern doesn’t make something a temperature proxy – a point that Preisendorfer mentions very clearly. The issue is whether strip bark bulges are unique antennae for world temperature, as dendro-phrenologists believe.

  35. BlogReader
    Posted Jul 29, 2010 at 10:46 AM | Permalink

    Amusing post from the realclimate blog post by BPL #145:

    Tamino: “I computed my own reconstructions by multiple regression, first using all 22 proxy series in the original MBH98 analysis, then excluding the Stahle and NOAMER PC1 series.”

    Jean S: Oh, I guess you simply forgot to exclude also the “Gaspe series” you later describe as “the most hockey-stick shaped proxy of all”. Why don’t you publish your results with the 19 remaining proxies?

    BPL: In other words, your criterion for what to exclude is “anything that looks like a hockey stick.” And you intend to use that to prove that there’s no hockey stick.

    Read my lips: It’s warmer now than in the past 2000 years. You don’t need MBH98-99 to prove it. Everybody else who does similar studies gets the same result.

    The Earth is warming. We’re doing it. And it’s the most serious problem civilization faces outside of nuclear war. Deal with it.

    I had to chuckle with the “read my lips” part — which I amuse is a reference to a politician that went back on his word. And the most serious problem civilization faces outside nuclear war? Not prone to hyperbole I see.

    And BPL’s general tone is anti-science and pro-ideology. Yes, include data that disagrees with your point. That’s why it is called “science” and not “Lysenkoism”

  36. HaroldW
    Posted Jul 29, 2010 at 5:57 PM | Permalink

    Sorry, this is not strictly relevant but I couldn’t help laughing at the following inserted ad:

    Train Your Biting Dog
    Read Articles & Tips that Can Help You Teach Your Dog Better Behavior.
    Iams.com/Dog-Biting

  37. TonyM
    Posted Jul 29, 2010 at 8:43 PM | Permalink

    I am neither a statistician nor climatologist but these question have been bugging me for some time and I have never seen them addressed. Maybe someone can answer them for me or point me to the information..

    Who decided (1) that tree ring data from a rather small geographic location on the planet, and from a relatively small number of trees, could be a proxy for average temperatures over the entire planet; (2) what is the scientific or mathematical justification for this assumption? (I suppose the same questions could be asked of ice core data from the poles.). (3) Doesn’t precipitation and soil chemistry impact tree rings? (4) By what mathematical method are these last factors eliminated from the data series?

    Doesn’t fundamental statistics require a random sample of a minimum number of observations from all over the planet to achieve some level of statistical confidence? Since 70% of the planet is ocean, it would seem thast tree rings are the last data that should be used.

  38. Posted Jul 30, 2010 at 12:42 PM | Permalink

    Steve

    Could you possibly do a ‘unilateral joint paper with the team’. Sounds strange but it would be useful if you could set out areas where there is agreement, where there is fundemental disagreement and where here are different interpretations?

    Ron

    • Posted Jul 30, 2010 at 12:57 PM | Permalink

      I’m pretty sure Steve made that offer early on, and was either refused or ignored.

      • Posted Jul 30, 2010 at 11:55 PM | Permalink

        I know Steve made the offer and it was rejected. My point is that it would be interesting to hear what Steve believes to be common ground even if the other side remains silent.

  39. Posted Aug 6, 2010 at 12:44 PM | Permalink

    SMc – 2+2=4

    Tobis – You should believe people who are smarter than you and we are much smarter than you

    SMc – 2+2=4

    Tobis – Mann is smarter than me and he says 2+2=5

    SMc – 2+2=4

4 Trackbacks

  1. By Top Posts — WordPress.com on Jul 28, 2010 at 7:06 PM

    [...] Tamino’s Trick: Mann Bites Dog Self-described “Hansen bulldog” Tamino, writing at NASA’s realclimate blog hosted by Hansen’s other [...] [...]

  2. [...] reason that I know what comments were rejected because many of these people subsequently posted on climateaudit or emailed me.  In one instance, a comment was rejected by CP from someone who had previously made [...]

  3. [...] been found to be questionable in a number of instances by a number of other parties. See here and here, for example. So I won’t bother with a new post that provides a detailed response to Tamino this [...]

  4. [...] been found to be questionable in a number of instances by a number of other parties. See here and here, for example. So I won’t bother with a new post that provides a detailed response to Tamino this [...]

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