Thursday, December 29, 2011


date: Mon Feb 10 14:25:31 1997
from: Keith Briffa <>
subject: reply to Gordon - Confidential

-Please note that some words intended to be stressed have been bracketed by asterisks -


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,


No comments:

Post a Comment