Steve McIntyre has released a sudden flurry of blog posts on the subject of the Briffa et al 2013 paper. Today's offering contains the eye-opening news that CRU have finally backtracked from the Yamal hockey stick of "most important tree in the world" fame. The new version of the series is no longer hockey stick shaped and the modern portions resemble closely the versions of Yamal posted at Climate Audit as long ago as 2009, for which McIntyre was resoundingly condemned by mainstream climatologists.
Rob Wilson sends this sensitivity analysis for the D'Arrigo et al 2006 paper, so that people can see the effect of excluding Yamal. Rob writes:
Below compared are mean NH composites (z=scores w.r.t. 1750-1950). Show[n] for period with at least 2 chronologies per continent (American and Eurasia).
Red line is DWJ06 without Wrangells or Yamal - little change.
Green line is an extended version of the Wilson et al. 07 study. Completely independent data-set to DWJ06
D'Arrigo et al was discussed in the Hockey Stick Illusion, where I noted that it includes some other dubious series, including Tornetrask. So while a lack of sensitivity to Yamal is interesting, I'm not sure I'm convinced yet. It would be interesting to know which series are driving the hockey stick shape, or whether it's a function of the methodology or something.