As an environmental plant physiologist, I have followed the long debate
starting with Mann et al (1998) and through to Kaufman et al (2009).
As time has progressed I have found myself more concerned with the whole
scientific basis of dendroclimatology. In particular;
1) The appropriateness of the statistical analyses employed
2) The reliance on the same small datasets in these multiple studies
3) The concept of "teleconnection" by which certain trees respond to the
"Global Temperature Field", rather than local climate
4) The assumption that tree ring width and density are related to temperature
in a linear manner.
Whilst I would not describe myself as an expert statistician, I do use
inferential statistics routinely for both research and teaching and find
difficulty in understanding the statistical rationale in these papers.
As a plant physiologist I can say without hesitation that points 3 and 4 do
not agree with the accepted science.