Through this error, they eliminated the key hockey stick pattern of long - term variation. (hubpages.com)
The claim by MM that the hockey stick pattern arises as an artifact of the PCA centering convention used by MBH98 is seen to be false on multiple levels. (realclimate.org)
The following paper addresses, and rebuts, criticism of the hockey stick pattern: «Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence» (judithcurry.com)