[Climate Audit was started on Jan 31, 2005. Prior to its startup I had some notes at a prior website http://www.climate2003.com, which John A transferred to the CA blog at its start-up.]
The Dec. 4 post “False Claims” refers to an article by Mann and his associates [Rutherford et al. 2004], supposedly discrediting our work. There is nothing in this article about the two main points in our Nature submissions:
1) the modification of the PC algorithm such that it produces hockey sticks in the PC1 from red noise;
2) the ad hoc and unique extrapolation of the Gaspé series.
It regurgitates the comments made in the Nov. 2003 Internet response in which Mann et al. attributed the difference in PC results to a stepwise procedure used in MBH98, but never previously reported. However, the calculations in our 2004 submissions implemented the stepwise procedures and isolated the difference to a completely different cause: the weird centering method introduced at line 168 of their Fortran program. Rutherford et al [2004] do not discuss this matter, although Mann et al. are obviously aware of the issue, as it is referred to in the first paragraph of the web posting.
It is interesting that this matter is being discussed in a Journal of Climate article. Jones and Mann [Rev Geophysics 2004] refers to a submission by Mann et al. to Climatic Change, which was said to have refuted our first submission. Does it strike anyone as odd that this submission mentioned in print over 6 months ago has not seen the light of day? Is it possible that something happened to the article at Climatic Change?