The Return of Yamal
Posted by Jeff Id on December 2, 2009
Something I was unaware of was the cooperation between Briffa and the collectors of the Yamal data and paper. Keith Briffa has an odd writing style where he’ll flat contradict his own paper and still come to the same conclusions. In this case I’ve long wondered about Hantemirov’s paper on Yamal and one particular statement in it. Keith Briffa Hokeysticizated Yamal after this graph was produced and his version is the one always used. In this case the unhockeysticizated version is discussed before publication. Oddly Briffa refused coauthorship.
From: Rashit Hantemirov <email@example.com>
To: Keith Briffa <firstname.lastname@example.org>
Subject: Re: Yamal paper for The Holocene special issue
Date: Wed, 21 Aug 2002 17:56:18 +0500
Reply-to: Rashit Hantemirov <email@example.com>
thank you very much for editing our paper. It’s a pity you strike your name off the list of authors, you
make an important contribution to writing paper. Your corrections and additions surely improve paper.
I would only notice the next sentence (page 8):
‘The low interannual variability and the minimum occurrence of cold extremes during the 20th century, argue that the most recent
decades of this long summer record represent the most favourable climate conditions for tree growth within the last four
I’m not sure that this statement follows unambiguous from results presented in this paper. Because mean temperatures during last
decades, according presented reconstruction, are not exceptional. Besides, e.g. period about 1700 BC, according this
reconstruction, represent probably the same conditions taking into account low variability, low occurrence of extremes and high
May be to soften this statement and replace ‘the most favourable’ with something like ‘highly favourably’ or ‘probably the most
Thank you once more for invaluable assistance.
Rashit M. Hantemirov
(I’m sorry for the late answer, I just come back from the trip to
Lab. of Dendrochronology
Institute of Plant and Animal Ecology
8 Marta St., 202
Ekaterinburg, 620144, Russia
I’ve bolded the important bit’s. The most favorable comment was written by Keith Briffa after seeing this data:
The most favorable ‘fastest growing’ section according to Brifa is the bit in the bottom right corner. Now in the paper Holocene_v12a the final version from what I gather read like this:
Recent warming is also clear, especially if it is judged to have
commenced at the beginning of the nineteenth century. The low
interannual variability and the minimum occurrence of cold
extremes during the twentieth century argue that the most recent
decades of this long summer record represent one of the most
favourable climate conditions for tree growth within the last
I’ve always wondered how that fit the interpretation of the incredibly flat curve above. In one of these emails I learned that Hantemirov was a young guy trying to work in this field. Briffa collaborated with them to get a lot of data from the Yamal region. I think this last paragraph in the papers discussion (link above) is pretty telling about the poor quality of temperature records from tree ring data.
The more northerly tree-line suggests that the most favourable conditions
during the last two millennia apparently occurred at around ad
500 and during the period 1200–1300. It is interesting to note that
the current position of the tree-line in Yamal is south of the position
it has attained during most of the last three and a half millennia,
and it may well be that it has not yet shifted fully in response
to the warming of the last century.
So from that version of Yamal using corridor standardization Briffa has used a different method on the same data and his reconstruction looks like this: