bender drew our attention to the following interesting paper from Evans et al (including Heghes and Vaganov) attempting the salutory exercise of forward modeling tree ring site chronologies from climate data. bender quoted from the intro:
Two major uncertainties lie in the statistical development, analysis and interpretation of tree-ring data for paleoclimate studies. First, there are nonclimatic influences on tree-ring records, including tree biology, size, age and the effects of localized forest dynamics [Cook and Kairiukstis, 1990]…. Perhaps of more concern is that tree ring data reflect a nonlinear response to multivariate climate forcings.
Read the whole paper for context. This shows the dendros are working on the problem.
I don’t have time to analyze the paper and merely bring it to people’s attention. For reference, the sites in question were said to be 190 MBH98 sites and 8 Russian sites.
Of these, 190 data series for North America are from the Mann et al.  data set. These data were screened a priori for several quality control variables [Mann et al., 2000] to produce a data set most conducive to paleoclimate reconstruction, and represent an excellent target for this study. Data from eight sites in Russia are from published or unpublished data sets developed by Vaganov et al. [1999, 2006, submitted manuscript, 2006].
Although this study is published in an AGU journal requiring data citation, the 190 MBH98 sites are not listed in an SI (nor the 8 Russian sites). There were 232 sites listed in the original SI, of which only 212 sites were actually used. In the location map, I noticed that there were no Alaska sites, so MBH98 Alaska sites appear to have been removed from the population for some reason. In the early screening which reduced the population from 232 sites to 212 sites, sites that were removed in order to “produce a data set most conducive to paleoclimate reconstruction” included the Hart’s Pass WA site (together with other Peterson sites in Washington). I mention this because the Hart’s Pass WA site is the only ITRDB site used by Rob Wilson in Wilson et al 2003 to supplement his own collection – so it would be interesting to know why this site is rejected by one dendroclimatological group and accepted by another. It would also be interesting to know why the Alaska sites were removed, as some of these were presumably temperature proxies.
Their Figure 2 is for the Ulan-Ude, Buryatia region, southern Siberia: 51.8N, 107.6E; 510 m elevation. It’s in the same general location as Barabinsk (57,5N, 97.5E), where I experimented with information on Russian stations, I’ll try to see what station data is available in Ulan-Ude at some point.
In terms of recent debate, the issue is not whether dendroclimatologists are or are not working on their problems, but whether the IPCC is over-selling.
Update: Here are a couple of graphics showing gridded and station data for Ulan-Ude and its gridcell. Several versions of station data are shown here. The station data shows a rather remarkable increase since the 19th century in the GHCN adjusted version (which does not incorporate recent Russian data.)
Evans, M. N., B. K. Reichert, A. Kaplan, K. J. Anchukaitis, E. A. Vaganov, M. K. Hughes, and M. A. Cane, A forward modeling approach to paleoclimatic interpretation of tree-ring data, J. Geophys. Res., 111, G03008, doi:10.1029/2006JG000166, 1-13, 2006