The Return of the Hockey Stick

[Crick]

Tell him I said Hi.

 

[Sunsettommy]

So, again (and again and again) you are forced to resort to ad hominem attacks because you have no facts or evidence supporting the position you've chosen to take. I hope you don't think anyone is impressed by such ignorant childishness.

No, it is YOU who REFUSE to accept the numerous findings published against the "hockey stick" because you are a pathetic warmist gook who prefer to think and act like a child with your numerous lies and omissions.

You will ignore this again....

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Climate Audit Files

CORRECTIONS TO THE MANN et. al. (1998) PROXY DATA BASE AND NORTHERN HEMISPHERIC AVERAGE TEMPERATURE SERIES

Stephen McIntyre 512-120 Adelaide St. West, Toronto, Ontario Canada M5H 1T1;

Ross McKitrick Department of Economics, University of Guelph, Guelph Ontario Canada N1G2W1

Energy and Environment

2003

ABSTRACT

The data set of proxies of past climate used in Mann, Bradley and Hughes (1998, “MBH98” hereafter) for the estimation of temperatures from 1400 to 1980 contains collation errors, unjustifiable truncation or extrapolation of source data, obsolete data, geographical location errors, incorrect calculation of principal components and other quality control defects. We detail these errors and defects. We then apply MBH98 methodology to the construction of a Northern Hemisphere average temperature index for the 1400-1980 period, using corrected and updated source data. The major finding is that the values in the early 15th century exceed any values in the 20th century. The particular “hockey stick” shape derived in the MBH98 proxy construction – a temperature index that decreases slightly between the early 15th century and early 20th century and then increases dramatically up to 1980 — is primarily an artefact of poor data handling, obsolete data and incorrect calculation of principal components

23 page PDF LINK

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Climate Audit

The Wegman and North Reports for Newbies​

Stephen McIntire

November 6, 2007

Excerpt:

In recent discussion of the Weblog 2007 Awards, several commenters at other blogs have argued that our criticisms of the Mannian parlor tricks have been “thoroughly refuted and discarded by climatologists, published in a credible journal”; that “other professionals in the field who also have “looked in great detail at the problem at hand” and have come to the conclusion that rather than McIntyre’s findings being “valid and relevant”, they instead have found them to be “without statistical and climatological merit”; that CA “fluffed on the whole hockey stick thing”. See for example here

Omitted in these references are the fact that the people described as “climatologists published in a credible journal” or “professionals in the field” are none other than Wahl and Ammann, serial coauthors with Michael Mann, students of Mann, who are not independent of the controversy. Indeed, they largely use (without citation or attribution or even acknowledgment to Michael Mann) arguments originally published at realclimate (and already responded to in MM 2005b(EE). Aside from their lack of independence, neither Ammann nor Wahl qualify as statistical authorities. Ammann did his undergraduate work in geology; Wahl in divinity. While this does not exclude them from having potential insight in the matter, it is evidence that one should not necessarily expect a sure grasp of mathematical and statistical issues and that their conclusions cannot be relied upon uncritically, even if Stephen Schneider accepted their article.

Readers interested in a third party view of the matter are far better off consulting the North Report, the Wegman report, (particularly) Wegman’s Reply to Questions and Richard Smith’s account of the 2006 American Statistical Association session. All of these individuals are vastly more eminent than Ammann and Wahl. Wegman, in particular, has been Chair of the National Academy of Sciences Committee on Theoretical and Applied Statistics and is a legitimate statistical expert. His comments on the Wahl and Ammann preprint are very acute and have not received appropriate consideration.

I’ve collated some of these remarks for the benefit of new readers who haven’t been following this particular story. Please read the comments below using the analogy from the previous post: see if any of our criticisms of Mannian parlor tricks have been refuted – as opposed to whether someone arguing that you can re-tool the trick to still saw the woman in half a different way. (And for this latter, pay particular attention to Wegman’s comments on Wahl and Ammann later in the post.)

The Wegman Report

The original Wegman Report is online here. Here are some excerpts from this report:

LINK