Mann et al 2008 – Another Error Notice

In previous posts, I’ve observed my inability to replicate Mann’s verification statistics, the source code for which was not archived despite representations to the contrary in the original article.

Mann has issued another uninformative correction notice (bearing the date Dec 1, 2008) which states:

UPDATE 1 December 2008: Supplementary Figure S8a had a small error due to improper calculation of the validation statistics. The corrected figure can be found here (PDF)

OK, now, pretty please, what are the properly calculated validation statistics? And, pretty please, where did the error occur?


  1. AndyL
    Posted Dec 5, 2008 at 2:14 PM | Permalink

    Did you also see in the readme

    ***UPDATED 29 November 2008 to add
    clihybrid.m to the codeprepdata directory.

  2. AndyL
    Posted Dec 5, 2008 at 2:26 PM | Permalink

    Apologies – this seems to have been spotted already. Google search didn’t find the update where UC uses it

  3. Jean S
    Posted Dec 5, 2008 at 2:52 PM | Permalink

    Of course, it is Figure S7a … is it so hard to get even the error notice straight? That figure is the comparison of the original CPS NH reconstruction and the one with the “potential problematic series” removed. The only way validation stats can affect that figure is through the network change issue. Comparing the original figure to the new one, that’s what seems to be going on since AD1000 step (in the “original-7″ series). Notice especially the large change in AD1100 step.

  4. Sam Urbinto
    Posted Dec 5, 2008 at 3:10 PM | Permalink

    How about The missing piece at the Wegman hearing?

  5. Clark
    Posted Dec 5, 2008 at 8:42 PM | Permalink

    At least one can conclude that Mann or one of his friends is reading here regularly.

  6. jae
    Posted Dec 5, 2008 at 8:47 PM | Permalink

    Dr. Mann seems to be trying, at least. That is a positive step. It is evident that the “forces” behind the scenes have heard Steve Mc loud and clear.

  7. Geoff Sherrington
    Posted Dec 5, 2008 at 9:37 PM | Permalink

    Man is a history-making creature who can neither repeat his past nor leave it behind.

    W. H. Auden (1907 – 1973) “The Dyer’s Hand,” 1963.

  8. PHE
    Posted Dec 6, 2008 at 2:21 AM | Permalink

    It is interesting to see that the proxy data indicate it was warmer in about the year 280 than in 2000. How can this be? This is not in line with the scientific concensus. The perhaps needs to be a bit more verification.

2 Trackbacks

  1. […] “Mann et al 2008 – Another Error Notice“, Steve McIntyre, Climate Audit, 5 December 2008 — Another correction by Mann, who […]

  2. […]  “Mann et al 2008 – Another Error Notice“, Steve McIntyre, Climate Audit, 5 December 2008 — Another correction by Mann, who seems unable to credit his critics. […]


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