It’s "interesting times" at realclimate.org where the authors feel the need suddenly to check their sources and the provenance of data in a way that they clearly didn’t before, and advise caution when the latest scare stories of global warming come in. For students of psychology, this points to an internal conflict of the psyche […]
This is an interesting and amusing comment on factor analysis, a technique very closely related to principal component analysis: J. Scott Armstrong, Derivation of Theory by Means of Factor Analysis or Tom Swift and His Electric Factor Analysis Machine, The American Statistician, 1967, 17-21 Link
This is the first replication note that gets into the meat of our emulation. Previously we’ve noted the non-replicability of certain MBH98 steps, but, since relevant intermediate calculations were archived, we were able to proceed using the archived intermediate calculations. Here we show the key replication step calculating “reconstructed [temperature] principal component” series. Archiving is […]
Khim et al. [2002] reported that a core from the Eastern Bramsfield Basin, Antarctic Peninsula showed that the LIA and MWP were the strongest of the Late Holocene cold and warm periods.
Millar, Constance, Robert Westfall, Diane Delany, John King and Harry Alden, Climate As An Ecosystem Architect; Responses Of High-Elevation Conifers To Past Climate Variability.
Here’s an interesting comment from an applied statistician about principal components:
A few comments on Mann’s interview on BBC4 in which Ross McKitrick and I were discussed. Given the seeming efforts to backpedal on the role of the hockey stick in promoting Kyoto, it was interesting to hear the BBC reporter state that it was "hard to over-estimate how influential that study [MBH98] and that image […]
One of the fun parts about finding the Hockey Stick is the many guises in which it appears. If you didn’t know what you were looking at, you could easily miss the significance of the information provided for you by people in authority. Today’s scientific authority is the government of New Zealand.
The calculation of temperature PC series needs to be distinguished from the calculation of tree ring PC series. Procedures for the handling of missing data in the temperature dataset were described in the MBH98 Corrigendum SI for the first time in July 2004, specifying that linear interpolation was done, but not specifying the handling of […]
The Wall Street Journal published this editorial last Friday, on the Hockey Stick controversy and the work of Steve McIntyre: Hockey Stick on Ice Politicizing the science of global warming. Friday, February 18, 2005 12:01 a.m. EST On Wednesday National Hockey League Commissioner Gary Bettman canceled the season, and we guess that’s a loss. But […]
Climate Audit 
A Reader's Comment about Principal Components
Here’s an interesting comment from an applied statistician about principal components: