cc: fritz.schweingruber@wsl.ch date: Mon Feb 10 14:25:31 1997 from: Keith Briffa subject: reply to Gordon - Confidential to: druid@ldgo.columbia.edu -Please note that some words intended to be stressed have been bracketed by asterisks - Gordon, I have sat for a few days and mused on the message you recently sent to me. I am still, however, somewhat bemused by its content and frankly, wondering how things seem to have reached what I can only describe as this undesirable situation. First, you say there is no work going on in the Taimyr region and inform me that you have submitted a proposal to do this. Let me state clearly that as far as I am aware significant work is going on in Taimyr. This is being coordinated in Russia from Eugene Vaganov's lab. and *not insignificant* funding already has, is, and will continue to come from here and from Fritz Schweingruber's resources to fund this work. Ed Cook, who, incidentally, said nothing to me about your proposal to work in Taimyr, is well aware of our involvement and considerable investment in time and money in the area, and indeed tried to play with some of the data from this area while he was working on his version of the RCS programme during his recent visit here. Both Stepan and Eugene are official contractors on my current EC grant and I have put a great deal of additional effort, trying (as yet unsuccessfully) to get them both more funds under the COPERNICUS initiative in Europe. This proposal will be resubmitted in 1997 - specifically to fund ongoing densitometry in the Taimyr area. A past joint initiative, submitted by Fritz and myself and our Russian colleagues, resulted in INTAS funding the entire purchase and installation of the densitometric equipment at Krasnoyarsk, and Fritz is also supplying additional funds ,where he can ,to continue this work. Note that the densitometer was, initially at least, justified specifically on the grounds of sub-fossil data analysis in Taimyr and this is the ongoing justification being used for the resubmission of the COPERNICUS proposal. Maybe you did not know, but there are more than just 'dots on the map' as far as Taimyr work goes. There is a continuous chronology reaching back to ....... and much additional and ongoing work based on subfossil data. There are also spatial reconstructions based on the ring width and density data, and papers in preparation and in press describing this work. All of this, it is true, is by the by, and of course I fully respect both Eugene's and Stepan's need to go out and attempt to get funding wherever they can. I couldn't agree more with you about the perilous state of Russian funding, and I fully support in any way possible their attempts to secure whatever funding they can. Likewise, I fully acknowledge your own right to follow your exploration and work wherever you see fit. I hear you are working anyway in places such as Norway, eastern Russia, central Russia, etc. etc. So be it. There are many approaches and none is entirely 'right' or exclusive of others. Nevertheless, the current picture of research, as presented in your note, is misleading: more frankly, it is simply wrong. My only purpose here is to state a 'truer' version of the state of affairs. As for your next point about the RCS, in theory, different aged cohorts of trees do not necessarily render the method inapplicable. Provided there is no systematic growth bias in different cohorts - i.e. provided enough natural climate variability *long term* is represented in the *total* sample, the RCS curve should be a reasonable model of expected growth with age. The real problem arises when there is bias in the samples at a particular time that is not related to a climate shift - i.e. if one cohort all derive from an elevation that is significantly different from the mean, or perhaps all from a more boggy site so that growth was suppressed overall by this fact alone, then this bias will be imparted to the final chronology. This, I believe, may be a common problem in long, poorly replicated sub-fossil derived chronologies, especially where the tree age is relatively short. However, I still believe these (and raw averages where replication is high) at least offer a prospect of seeing long-term change that would otherwise be definitely removed. I am currently redoing the standardization of all of our chronologies, in an attempt to produce a grand reconstruction over the whole network - not with RCS which is definitely inapplicable to generally even-aged stands of trees - but with simple straight- line standardization. Now, let me turn to your last remarks. These, of course, epitomise a long standing and, in my opinion, disappointing polarity that has developed between you and Fritz over recent years. I stand in the middle - this is very different from 'sitting on the fence' inasmuch as I am not taking sides. On the contrary, I disagree with both of you and feel it is a great pity that you can't find more common ground. I know you both well and am happy to consider you both as friends. There are people in this field whose motives or at least methods I have always regarded with suspicion. You two, however, are motivated only by genuine scientific goals. Now it seems you have adopted positions which you both consider mutually exclusive and it is a great pity that you have taken up positions behind 'the barricades'. It is a greater pity that you can't respect each other's genuine concern for the subject and the contribution that each of you has made, and continue to make. Frankly, I think the disagreement started from little, grew unreasonably because of misunderstanding, and has become fossilized largely because of stubbornness. You specifically asked for my comments, so here they are. I think (as does Fritz) that you have been able to locate 'extreme' sites where greater recent ring-width increases occur than are apparent in many other northern or high altitude sites. Which of the sites is 'typical' and 'of what' are the most pertinent questions. It is possible that your sites are the 'odd' ones because they reflect extreme sensitivity to recent warming or even perhaps to some change in another growth limiting factor, e.g. Nitrate input. However, where I think you and Fritz have possibly gone wrong is in adopting too rigid interpretations of what your data, or Fritz's data, say about global change questions. The subject is long and involved, but I think you are both wrong if you insist on maintaining an aggressive attitude to each other's data. There are several questions relating to the various data, the forcing factors (not just climate), their manipulation (standardization and chronology construction) and the statistical interpretation of their variability. It would take me too much time to detail all this here. Basically, I think both of your data sets can be presented and possibly interpreted in different ways. My personal opinion is that you may both be laying too much stress on your opinions and that you are both potentially right and wrong in different aspects. There is a need for you and others to talk constructively together - informally, and without axes to grind - about this. What the subject in general does not need is sweeping statements, oversimplifying and partly misrepresenting each other's positions. I hope you will forgive my cheek in saying this - but I consider both of you to be true pioneers in the field and - I was asked. You both have my greatest regard and respect, and I think some more constructive interaction needs to be reinjected between you. I have always considered honest and open talk best, and that has been my justification for this note. Best wishes, Keith