The MBH98 Corrigendum

The SI for MBH98 listed 34 tree ring series that were not actually used. This was acknowledged in their 2004 Corrigendum which provided the following implausible excuse:

These series, all of which come from the International Tree Ring Data Bank (ITRDB), met all the tests used for screening of the ITRDB data used in ref. 1 (see ref. 5), except one—namely, that in 1997, either it could not be ascertained by the authors how these series had been standardized by the original contributors, or it was known that the series had been aggressively standardized, removing multidecadal to century-scale fluctuations.

A number of the unused series were generated by Schweingruber. Other Schweingruber series arising from the same collection and publication were used in MBH98, making the application of the Corrigendum excuse to the Schweingruber series highly implausible to say the least. Other unused series were generated by prominent dendrochronologists in published articles, whose methodologies were either published or easily available to MBH. Whatever the actual reason for the omission of the 34 series, the above reason seemed highly implausible.

On a small whim, I cross-checked the Mann et al 2008 against the Corrigendum exclusions.

25 of the 34 series said to be unsuitable in the Corrigendum were used directly in Mann et al 2008; 4 excluded Schweingruber MXD series are used in the MXD grid. The only series not used in Mann et al 2008 are 4 Schweingruber RW series and one oddball (chil016, a Roig series – other Roig series are used.)

For 23 of the 25 series, the versions used in Mann et al 2008 are identical to the ITRDB version, previously said to be unsuitable in the Corrigendum. For the other 2 (arge065, cana106), the version differences were not material.

28 Comments

  1. Dodgy Geezer
    Posted Sep 29, 2008 at 5:24 PM | Permalink

    Someone could write a whole book on the unusual methods of Professor Mann…. Oh, I’m sorry, Steve – you already have…..

  2. Kohl Piersen
    Posted Sep 29, 2008 at 5:49 PM | Permalink

    How does this bloke get away with it?
    When will IPCC and others finally wake up to his inaccuracies, prevarications and exaggerations?
    Oh! I forgot! He writes the IPCC book doesn’t he?

    • Raven
      Posted Sep 29, 2008 at 6:10 PM | Permalink

      Re: Kohl Piersen (#2)
      Wizards First Rule:

      People are stupid. They will believe a lie because they want to believe it’s true, or because they are afraid it might be true

      h/t Terry Goodkind

  3. Jonathan DuHamel
    Posted Sep 29, 2008 at 7:29 PM | Permalink

    I hope at some point you will summarize the whole Mann thing in terms a layman can understand.

    • Craig Loehle
      Posted Sep 29, 2008 at 8:02 PM | Permalink

      Re: Jonathan DuHamel (#4), I’m sorry, but if you are smart enough to understand it, your head explodes. Catch-22.

  4. philh
    Posted Sep 29, 2008 at 8:43 PM | Permalink

    # 4: You might want to read the McKitrick paper: “What the Hocky Stick Debate is About.” This thing has been going on for quite a while. I am a layman but I think I have a pretty good general idea about what’s involved. In simplest terms it is about the inability, for whatever reason (ie.,because of the lack of expertise of Mann and his cohorts with fundamental statistical processes, or, a deliberate attempt by them to corrupt statistical data in order to prove their basic premise that late 20th Century and early 21st Century global temperatures are the warmest in more than a thousand years), of Mann and his team to deal on a scientifically sound basis with the question of anthropogenic global warming. Most visitors here, and the proprietor of this site, agree that there has been some warming in the last century, but either disagree with or are not sure about the proposition that such warming which has occurred has been caused by man or that it is warmer now than at anytime in the last thousand years. The reasons that Steve has had to continue to monitor these folks is because (1.)they keep making these stupid errors; (2)they have stonewalled almost every attempt to gain access to their data and to their computer codes; (3) the so-called “peer reviewed” scientific journals these people publish in are not properly or conscienciously reviewed at all and their errors and misstatements are rarely if ever called out; (4) the celebrity treatment their incorrect “results” are given by the gullible media and by the IPCC;(5) Steve is one of the few statisticians in the world who is interested enough in this, and is capable of ferreting these people out and is not afraid to do so, and, finally, because literally trillions of dollars and millions of lives are at stake here. It is one of the most important issues of this century and we really, really ought to have honest science on which to base our decisions.

  5. Gerald Machnee
    Posted Sep 29, 2008 at 9:11 PM | Permalink

    The question I have is: Why were they used now? Maybe I can answer that as well: the vintage has improved as noted in another thread.

  6. Posted Sep 29, 2008 at 9:43 PM | Permalink

    It might be a pain in the butt, but could you list the proxy names used in 08. I am curious what the curves look like.

  7. Jeff Alberts
    Posted Sep 29, 2008 at 9:49 PM | Permalink

    I’m sorry, but if you are smart enough to understand it, your head explodes. Catch-22.

    I’m smart enough that all these shenanigans just confirm my faith in human nature and human gullibility.

  8. thefordprefect
    Posted Sep 30, 2008 at 5:36 AM | Permalink

    Am I wrong in assuming this is the complete Mann datasets from 2008 including originals posted on 9th September 2008

    http://www.ncdc.noaa.gov/paleo/pubs/mann2008/mann2008.html

    Seems to have included full code as well so seems to be full transparency! I’m sure you will correct me if I am wrong.

    • Luis Dias
      Posted Sep 30, 2008 at 6:18 AM | Permalink

      Re: thefordprefect (#10),

      Seems to have included full code as well so seems to be full transparency!

      I want to understand better the reasons why you asked this. Yes, transparency has been a core concern against Mann et al, but why did you post this comment in a thread that had nothing to do with it?

      I suppose you read something about Mann and went to RC or some other climate blog and posted that as a question and then they responded by saying that Mann is transparent and that such criticisms are unfounded and ad hominems, etc.

      Am I spot on? Or completely off base? Thanks.

      • thefordprefect
        Posted Sep 30, 2008 at 8:57 AM | Permalink

        Re: Luis Dias (#12),
        I simply posted because many seemed to be saying where is the code, where are the data sets. I assumed none had seen this NOAA site. I arrived here from a sceptics referral!
        Cheers, Mike

        • Sam Urbinto
          Posted Sep 30, 2008 at 9:51 AM | Permalink

          Re: thefordprefect (#14),

          As Steve said, this is better than in the past, from this source at least. But it’s not totally fixed nor did it used to be this way. Some of the information is out there, but some isn’t. What is isn’t in the best of shape. It’s better tahn before, but…. And so on.

          A little editing and paraphrasing:

          The transparency of Mann’s work is MUCH better this time than last time. For example, MBH99 procedures for the calculation of confidence intervals and principal component retention remain unexplained after all these years.

          But there are still issues with the new work, such as the WDCP “original” proxy version no longer matches the dataset at Mann’s own website, which has been altered. So right now we don’t know for sure which of the two datasets is the “original” data that was actually used to produce his results. Changes have been made without change logs or documentation. The code is illustrative, but is incomplete or non-functional in important aspects. The code for the screening operations is not posted. The code is poorly written so that determining the underlying mathematics is not straightforward.

          But this current documentation is very good (by standards in this field) compared to the past. This makes it possible to analyze this paper in a matter of weeks rather than over multiple years.

    • Will J. Richardson
      Posted Sep 30, 2008 at 7:29 AM | Permalink

      Re: thefordprefect (#10),

      seems to be full transparency!

      I have often encountered such “transparency” from “hired gun” expert witnesses. Their logic is this: My opinion is A. But if you check my data and calculations carefully you can determine that it really results in opinion B, not A. But my opinion A is not a lie because I disclosed the data and calculations which contradict opinion A. I have been entirely transparent!

      Regards,

      WJR

  9. Steve McIntyre
    Posted Sep 30, 2008 at 6:08 AM | Permalink

    #10. The transparency of Mann’s work is MUCH better this time than last time; I presume that this is a response to criticism. These datasets and code have been discussed at length in various threads here; everyone is aware of them. Unfortunately, the WDCP “oeiginal” proxy version no longer match the dataset at Mann’s own website, which has been altered. So right now we don’t know for sure which of the two datasets is the “original” data that was actually used to produce his results. Changes have been made without change log or documentation – a violation of transparency standards.

    The code is illustrative, but is incomplete or non-functional in important aspects. The code for the screening operations is not posted. The code is poorly written so that determining the underlying mathematics is not straightforward.

    Having said that, the documentation is very good by standards in the field. This is making it possible to analyze this paper in a matter of weeks rather than the multi-year quasi-litigation involved in MBH99, where, for example, procedures for the calculation of confidence intervals and principal component retention remain unexplained after all these years.

  10. Steve McIntyre
    Posted Sep 30, 2008 at 10:52 AM | Permalink

    #14. Remember that there have been years of fighting to get this sort of thing done. However, important underlying data sets are unarchived e.g. Lonnie Thompson’s ice core data is only available in 10 year summaries and inconsistent versions are floating around. CRU has refused to make their data as used available. Their code is not disclosed. Mann and Jones 2003 remains a mystery. So yes this is better, but please don’t imply that this disproves a long history of problems or that it resolves all outstanding issues.

  11. Brian M. Flynn
    Posted Sep 30, 2008 at 11:11 AM | Permalink

    Re: Jonathan DuHamel (#4),

    Try Bishop Hill’s, “Caspar And The Jesus Paper”, at:
    http://bishophill.squarespace.com/blog/2008/8/11/caspar-and-the-jesus-paper.html for a layman’s version in context – to a point.
    As to the latest Mannipulation, a “layman’s style” SI will evolve.

  12. Sam Urbinto
    Posted Sep 30, 2008 at 12:45 PM | Permalink

    Right answer = good science.

    Method = immaterial.

    You say tomato and I say tomato.

  13. darwin
    Posted Sep 30, 2008 at 3:54 PM | Permalink

    #18 — “Right answer”? Define, please. A person can get the “right answer” twice a day from the face of a clock, but be wrong for all the other 86,398 seconds. Tomato, tomate; potatoes, papas.

    • bender
      Posted Sep 30, 2008 at 4:02 PM | Permalink

      Re: darwin (#19),
      Sam is making a back-handed reference of irony (he often does that) to the Wegman equation:

      Right Answer + Wrong Method = Bad Science

      This is his way of referring Duhamel, the reader asking for a “lay summary”, to the original Wegman and NAS reports that underlie the Bishop Hill story on Caspar Ammann. I think his point is that there are many, many ways to summarize this story. That asking for just one summary is asking too much given all the possible variants.

      • darwin
        Posted Oct 2, 2008 at 2:36 PM | Permalink

        Re: bender (#20) Bender — I should have thunk that. Sam, apologia.

  14. Francois Ouellette
    Posted Sep 30, 2008 at 4:07 PM | Permalink

    I may be facing stonewalling myself. Ed Cook hasn’t replied, and I’ve had no reply from Barbara Hébert about her data on old gaspe cedars, even after one kind reminder. Maybe she googled my name and dendrochonology, and found my post here… or maybe I’m just paranoid… oops, gotta take my medicine…

    • Kenneth Fritsch
      Posted Sep 30, 2008 at 4:30 PM | Permalink

      Re: Francois Ouellette (#21),

      Maybe she googled my name and dendrochonology, and found my post here… or maybe I’m just paranoid… oops, gotta take my medicine…

      In my mind, true and diligent scientists are always happy to provide data for others to analyze and in fact should relish a second opinion and the opportunity to debate a difference of interpretation.

      A no reply speaks as loudly as a refusal in defining the scientist, but probably does not allow one to make the distinction between the potential deficiencies in true and diligent.

  15. bender
    Posted Sep 30, 2008 at 4:31 PM | Permalink

    Give her a break. People are busy. Please, no piling on.

  16. Armand MacMurray
    Posted Oct 1, 2008 at 12:41 AM | Permalink

    bender’s right, especially since there’s no easy way to verify that an email actually got through to a person. Phone calls are cheap enough these days, and don’t suffer from that defect.

    • Kenneth Fritsch
      Posted Oct 1, 2008 at 10:29 AM | Permalink

      Re: Armand MacMurray (#24),

      As I recall Francois was already in email contact with Ms Hebert, but as a further explanation of my previous post to this thread, it was based on a request for data that is fully acknowledged by the requestee. I do think, however, that the length of time it takes for an acknowledged response from a scientist is a legitimate factor in judging that scientist. In the meantime, I agree to be more patient and not jump to any conclusions.

  17. Skiphil
    Posted Dec 7, 2012 at 8:23 PM | Permalink

    I think this part of the comments from philh is an elegant summary of why the scientific status of all this sloppy (and worse) work by Team Mann continues to merit closer scrutiny now and for the indefinite future (for anyone with the interests and means to follow up on the many CA threads through the years):

    The reasons that Steve has had to continue to monitor these folks is because
    (1)they keep making these stupid errors;
    (2)they have stonewalled almost every attempt to gain access to their data and to their computer codes;
    (3) the so-called “peer reviewed” scientific journals these people publish in are not properly or conscienciously reviewed at all and their errors and misstatements are rarely if ever called out;
    (4) the celebrity treatment their incorrect “results” are given by the gullible media and by the IPCC;
    (5) Steve is one of the few statisticians in the world who is interested enough in this, and is capable of ferreting these people out and is not afraid to do so,

    and, finally, because literally trillions of dollars and millions of lives are at stake here. It is one of the most important issues of this century and we really, really ought to have honest science on which to base our decisions.

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