So what can we conclude on the basis of this and McIntyre's sensitivity tests? Does either version of the Yamal chronology as presented in Briffa (2000) and Briffa et al. (2008) present a misleading indication of the likely history of tree-growth changes near the tree line in the Yamal region over the last two millennia, or can McIntyre's "sensitivity analysis" be taken as evidence that tree growth has not increased in this region in the second half of the 20th century as is clearly implied by the "extreme" version of the Yamal chronology he produced? On the basis of the evidence we report here, the answer is very likely "NO" on both counts.and, oh yes, as Eli said about who owned the data
McIntyre states "If the non-robustness observed here prove out .. this will have an important impact on many multiproxy studies ...". We have shown here that the "KHAD only" example constructed by McIntyre itself represents a biased chronology, contradicted by the evidence of other chronologies constructed using additional and more representative site data. The evidence does not support a conclusion that our previous work was in any way seriously flawed. The last 8 years of our chronology ARE based on data from a decreasing number of sites and trees and this smaller available sample does emphasise the faster growing trees, so this section of the chronology should be used cautiously. The reworked chronology, based on all of the currently available data is similar to our previously published versions of the Yamal chronology demonstrating that our earlier work presents a defensible and reasonable indication of tree growth changes during the 20th century, and in the context of long-term changes reconstructed over the last two millennia in the vicinity of the larch treeline in southern Yamal.
Briffa has also been attacked by McIntyre for not releasing the original ring-width measurement records from which the various chronologies discussed in Briffa (2000) and Briffa et al. (2008) were made. We would like to reiterate that these data were never "owned" by the Climatic Research Unit (CRU) and we have never had the right to distribute them. These data were acquired in the context of collaborative research with colleagues who developed them. Requests for these data have been redirected towards the appropriate institutions and individuals. When the Briffa (2000) paper was published, release of these data was specifically embargoed by our colleagues who were still working towards further publications using them. Following publication of the 2008 paper, at the request of the Royal Society, Briffa approached colleagues in Sweden, Ekaterinburg and Krasnoyarsk and their permission was given to release the data. This was done in 2008 and 2009. Incidentally, we understand that Rashit Hantemirov sent McIntyre the Yamal data used in the papers cited above at his request as early as 2nd February, 2004.Go RTFL and then go read CA if your stomach can take it. Of course, Steve interprets caution as something that he does not do.
The Climatic Research Unit has never been a prolific producer of tree-ring records, focussing mainly on the collaborative analysis of data generously provided by other institutions. We will continue to respect restrictions placed upon the dissemination of data by those colleagues who provide them. All of the data produced at CRU (sampled from living oaks or pines at various sites around the UK and Scandinavia) have been provided on request. (All of the data used or produced in the analysis described here are provided on the Data page.)