Future prospects - Ice Ages and Interglacials: Measurements, Interpretation, and Models - page 342

3. Use of the temperature profile in the 1902-1995 time span for centering leads to
misuse of principal component analysis. However, the narrative in MBH on the
surface sounds entirely reasonable and could easily be missed by someone who is
not extensively trained in statistical methodology.
4. The cryptic nature of some of the MBH narratives requires outsiders to make
guesses at the precise nature of the procedures being used.
5. Generally speaking, the paleoclimatology community has not recognized the
validity of the McIntyre and McKitrick criticisms and has tended to dismiss
their results as being developed by biased amateurs. The paleoclimatology com-
munity seems to be tightly coupled and has rallied around the MBH position.
6. Widely quoted assessments that the 1990s were the hottest decade in a
millennium and that 1998 was the hottest year in a millennium cannot be
supported by a proper rendition of the MBH analysis

The paucity of data
in the more remote past makes hottest-in-a-millennium claims essentially
unverifiable.
7. The use of bristlecone pine proxies are inappropriate because they were probably
CO 2 fertilized. Therefore, it is not surprising that this important proxy in MBH
yields a temperature curve that is highly correlated with atmospheric CO 2 . There
are clearly confounding factors for using tree rings as temperature signals.

...

The ruling paleoclimatic cabal, all ardent alarmists, used their influence to
gain support for their basically untenable position by the United Nations, the
National Academy of Sciences, and other influential institutions. The details of
this entire saga are described in some detail by Rapp (2008). As a result, MBH
acquired widespread support for bad science via the consensus route. As it turns
out, the criticism heaped upon the hockey stick did not go unnoticed. While Mann
and co-workers never acknowledged the existence of McIntyre and McKitrick (or
other critics of the hockey stick) they did respond to a suggestion of the National
Research Council and revisited the subject via Mann et al. (2008). This paper, like
its predecessors, is basically unreadable except perhaps to a handful of narrow
specialists. While the paper purports to respond to criticism regarding the use of
tree ring proxy data, it does not seem to respond to the fundamental flaw
(reported previously by M&M and Wegman) of basing anomalies on the average
value over the standardization period. The mathematical procedures used in the
process are so abstruse as to hide the original data completely. But when the
original proxy data are examined 10 the overwhelming majority of these proxies
show no hockey stick trend at all, and it is clear that the report of an even more
extreme hockey stick (than previously) represents a mathematical artifice—not a
true averaging of the data. Furthermore, there is no basis for treating all proxies
as equally valid. The Mann et al. (2008) results are in conflict with a large amount
of their own data. It seems likely that the combination of mathematically aver-
aging large amounts of democratically treated noisy proxy data will tend to cancel

10 Graphs for all the 1,209 proxies are available at http://www.climateaudit.org/data/images/
mann.2008/