Just a quick interjection to note that the Yamal story has reached Andrew Orlowski of “The Register” under the title “Treemometers: a new scientific scandal“. [Steve: John A posted up this thread. I do not endorse everything in the article linked here. I also link to realclimate from time to time without agreeing with it.
The conclusion is worth savouring:
As the panel states, its duty is "assessing the scientific, technical and socioeconomic information relevant for the understanding of the risk of human-induced climate change. It does not carry out new research nor does it monitor climate-related data." But as lead author, Briffa was a key contributor in shaping (no pun intended) the assessment. A small group was able to rewrite history.
When the IPCC was alerted to peer-reviewed research that refuted the idea, it declined to include it. This leads to the more general, and more serious issue: what happens when peer-review fails - as it did here?
The scandal has only come to light because of the dogged persistence of a Canadian mathematician who attempted to reproduce the results. Steve McIntyre has written dozens of letters requesting the data and methodology, and over 7,000 blog posts. Yet Yamal has remained elusive for almost a decade
Update: The Yamal story in German is here: http://www.readers-edition.de/2009/09/30/das-ende-der-klima-wissenschaftlichen-glaubwuerdigkeit-ein-drama-in-5-akten/
For beginners, Bishop Hill has produced a new blog post on the impact of the Yamal deconstruction called "The Yamal Implosion"