[grey_whiskers]

Is the faulty computer program availabile on the web or elsewhere?

The obvious study is to take their program and systematically vary the length of the time period over which the normalization is performed, and compare the resultant predictions.

Somehow, it would nor surprise me to find that they
'accidentally' (of course) happened to choose the one
time period for the normalization procedure which would
maximize the appearance of global warming in the late 20th
century and beyond.

[Steve Schulin]

The fortran code Mann et al 1998 used to prepare the tree ring data for PCA is available at:

ftp://holocene.evsc.virginia.edu/pub/MBH98/TREE/ITRDB/NOAMER/pca-noamer.f

As for the PCA itself, Mann et al just say it's conventional, without mentioning any particular software.