Hi Ed - thanks for trying to fit something in quick for the NRC group. I'm not sure about
Richard's full motives, but I think he has his heart in the right place - that the NRC
Committee might have gotten the impression he did, and this will be reflected in their
report, perhaps in a way that is even less satisfactory to you and Keith. And, this report
will likely have enormous political potential. It needs to get things as right as possible
from the start. So... time well spent on the part of you and Keith. Thanks much, peck
Hi Peck,
Being in Bangkok, on to PACLIM, on to CONCORD in Mendoza, back to Bangkok, and back to
NY on May 1 makes it difficult for me to do much, but I will do what I can to salvage a
bad situation. The longish emails I sent out to you all contain much of what I would
write. The main point to make, one that Richard seems to be totally oblivious to, is
that there is no evidence for loss of sensitivity prior to the 20th century in a
large-scale NH sense like that seen in the 20th century. On the other hand, there is
evidence that there was not a loss of sensitivity in a large-scale NH sense in my QSR
paper (Fig. 6). I acknowledge the weakness in the data prior to about 1200, but even so
the regional comparisons only show divergence between north and south in the 20th
century, with none indicated during the putative MWP. So why is Richard and the NRC
panel apparently stating without evidence that divergence probably is a problem in the
past and, therefore, tree rings cannot be trusted to reconstruct past temperatures? It
is honestly unscientific when the only evidence that I have seen refutes that premise,
and it plays unfairly into McIntyre's hand. I almost admit to being very irritated that
Richard should anoint himself as the arbitrator of this debate. He knows nothing
substantive about tree rings. In that sense, he is just like Ray Bradley.
Cheers,
Ed
On Mar 14, 2006, at 6:29 AM, Jonathan Overpeck wrote:
Hi Ed and Keith - I hate to say it, but Richard's take on the political aspects of the
NRC vs. IPCC reports seem worth some extra effort. Since you were both invited to speak
with the NRC committee, I would suggest that you both (together or separately) submit
formal comments asap. I don't know when the comment period starts or ends, but I'm
guessing you have to work fast. I'm also thinking that you two might want to get out a
peer-reviewed paper on the topic really soon too. I worry that the hole will continue to
deepen for dendroclimate if you two don't act to clarify what we know/don't know, and
when it is safe (and why) to use dendroclimate data to address the issue of long-term
variation in temperature.
Please don't construe my suggestions or comments as pro/con dendro, but rather just as
someone who wants the truth - whatever it is - to be communicated clearly, and as best
we know it. But, I do think that if Richard is suspect, dendro has a real problem. He
doesn't have a personal bias in this, and is clearly trying harder than most to
understand what's really going on with climate and the proxies.
Effort now might save time later.
Also, are you both going to be at the Swiss mtg in June? We really have to get this all
ironed out better before the next (last) draft of the IPCC AR4.
Thanks, Peck
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795
[1]
[2]
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795

References
1.
2.


Hi Ed (and Keith) - this looks good. For what it's worth, here are some comments:
1. I agree Keith should send in an independent letter by email too (I'd put both on
letterhead or at least include as pdf attachments, so email forwarding wouldn't have the
chance of messing it up) .
2. I would say right up front - first line that you'd like your letter (s) to go to all
committee members, if possible with a cc to you. Don't leave any wriggle room.
3.  cc to G. North and B. Otto-Bliesner - again, so there is no doubt that this gets to
everyone
4. no need to mention IPCC. Focus on the science and the NRC review. Don't want to
introduce extra politics.
Thanks both for doing this - I agree there is a real need to ensure that the panel has the
science from the experts.
Best, peck
Hi everyone,
Here is a draft of what I want to quickly send to
Ian Kraucunas, Ph.D.
Board on Atmospheric Sciences and Climate
National Research Council of The National Academies
500 Fifth Street NW, Keck 705
Washington, DC 20001
Email: ikraucunas@nas.edu
Phone: (202) 334-2546
Fax: (202) 334-3825
He originally invited me to talk before the NRC. I do not have any other information on
who to send it too. Please let me know what you think, but don't be too pedantic or
critical at this stage. I get the feeling we have very little time to make an impact on
the NRC committee and its report. I personally think that I am correct as far as I can
take the argument. Let me know if I should send this on to Richard as well.
Ed
Dear Ian,
I have heard via emails and telephone conversations about some rather serious
developments that could have an unfairly negative impact on the use of tree rings for
reconstructing past climate and the upcoming IPCC assessment, especially that related to
surface temperatures. Apparently as part of her talk Rosanne D'Arrigo mentioned the
phenomenon of "divergence" between instrumental temperatures and tree growth in the
latter few decades of the 20th century. The large-scale nature of this phenomenon was
first described in Nature by Keith Briffa back in 1998 (Briffa et al., 1998) and to this
day its cause is not well understood at all. A number of hypotheses have been mentioned,
which range from natural (climatic change) to anthropogenic (i.e. pollution related),
but the actual cause is still unknown.
Somewhat alarmingly, it is my impression now the the NRC committee members and other
influential participants of the meeting have come to the conclusion that the observed
20th century "divergence" calls into serious question the value of the tree-ring
reconstructions of temperatures over the past millennium. The implicit assumption being
made is that the "divergence" is being caused by climatic change related to 20th century
warming, conditions that could have also prevailed back during the Medieval Warm Period
(MWP) some 800-1000 years in the past. If this were the case, then the concerns of the
committee would be justified.  However, the available evidence does not support such a
conclusion. In a paper I published in Quaternary Science Reviews in 2004 (Cook et al.,
2004), I reviewed the properties and interpretation of the tree-ring data used in the
Esper et al. (2002) paper published in Science. The reasonably well distributed set of
tree-ring data in both boreal and more temperate latititude sites around the Northern
Hemisphere allowed me to split up the data into sub-regional ensembles, including 8
sites in the 55-70° north band and 6 sites in the 30-55° south band. The purpose was to
show the overall robustness of the multi-centennial temperature signal in the tree-ring
data. This plot from the QSR paper is attached below as is the paper itself.
In his 1998 paper, Briffa showed that the divergence was largely restricted to the
region covered by the north band described in Cook et al. (2004). Consistent with that
finding, the north ensemble mean shown below reveals a serious downturn in growth after
about 1950. This is an expression of the "divergence" that has been described first by
Briffa and also by D'Arrigo in her NRC talk. In contrast, the south ensemble mean shows
the opposite, i.e. a substantial growth increase which is much more consistent with 20th
century warming. If one than follows the plots back in time, all of the sub-region
ensemble means track each other remarkably well at multi-centennial time scales even
when they enter the putative MWP 800-1000 years ago. In fact, at no time prior to the
20th century is there separation between north and south that is remotely comparable to
that found after ca. 1950. This result suggests that no large-scale "divergence" of the
order found during the 20th century occurred during the MWP even though that period is
suggested to have been somewhat warmer than average overall. This result clearly refutes
the argument that "divergence" of the kind noted in the 20th century happened in the
past. It also suggests a unique anthropogenic cause to the 20th century divergence.
I am not aware of ANY evidence that demonstrates the occurrence of large-scale
"divergence" in the past. It is therefore unjustified to call into question the use of
tree rings for reconstructing temperatures over the past millennium based on a naive
extrapolation of growth "divergence" into the past when it appears to be unique to the
20th century. The NRC committee members must be made aware of this if their report is to
have the necessary scientific credibility that is expected of it.
Sincerely,
Edward R. Cook
References
Briffa, K.R., Schweingruber, F.H., Jones, P.D., Osborn, T.J., Shiyatov, S.G., Vaganov,
E.A. 1998. Reduced sensitivity of recent tree-growth to temperature at high northern
latitudes. Nature 391: 678-682.
Esper, J., Cook, E.R., Schweingruber, F.H. 2002. Low-frequency signals in long tree-ring
chronologies for reconstructing past temperature variability. Science 295: 2250-2253.
Cook, E.R., Esper, J., D'Arrigo, R.D. 2004. Extra-tropical Northern Hemisphere land
temperature variability over the past 1000 years. Quaternary Science Reviews 23(20-22):
2063-2074.
?
?
Hi everyone,
Here is a draft of what I want to quickly send to
Ian Kraucunas, Ph.D.
Board on Atmospheric Sciences and Climate
National Research Council of The National Academies
500 Fifth Street NW, Keck 705
Washington, DC 20001
Email: [1]ikraucunas@nas.edu
Phone: (202) 334-2546
Fax: (202) 334-3825
He originally invited me to talk before the NRC. I do not have any other information on
who to send it too. Please let me know what you think, but don't be too pedantic or
critical at this stage. I get the feeling we have very little time to make an impact on
the NRC committee and its report. I personally think that I am correct as far as I can
take the argument. Let me know if I should send this on to Richard as well.
Ed
Dear Ian,
I have heard via emails and telephone conversations about some rather serious
developments that could have an unfairly negative impact on the use of tree rings for
reconstructing past climate and the upcoming IPCC assessment, especially that related to
surface temperatures. Apparently as part of her talk Rosanne D'Arrigo mentioned the
phenomenon of "divergence" between instrumental temperatures and tree growth in the
latter few decades of the 20th century. The large-scale nature of this phenomenon was
first described in Nature by Keith Briffa back in 1998 (Briffa et al., 1998) and to this
day its cause is not well understood at all. A number of hypotheses have been mentioned,
which range from natural (climatic change) to anthropogenic (i.e. pollution related),
but the actual cause is still unknown.
Somewhat alarmingly, it is my impression now the the NRC committee members and other
influential participants of the meeting have come to the conclusion that the observed
20th century "divergence" calls into serious question the value of the tree-ring
reconstructions of temperatures over the past millennium. The implicit assumption being
made is that the "divergence" is being caused by climatic change related to 20th century
warming, conditions that could have also prevailed back during the Medieval Warm Period
(MWP) some 800-1000 years in the past. If this were the case, then the concerns of the
committee would be justified.  However, the available evidence does not support such a
conclusion. In a paper I published in Quaternary Science Reviews in 2004 (Cook et al.,
2004), I reviewed the properties and interpretation of the tree-ring data used in the
Esper et al. (2002) paper published in Science. The reasonably well distributed set of
tree-ring data in both boreal and more temperate latititude sites around the Northern
Hemisphere allowed me to split up the data into sub-regional ensembles, including 8
sites in the 55-70° north band and 6 sites in the 30-55° south band. The purpose was to
show the overall robustness of the multi-centennial temperature signal in the tree-ring
data. This plot from the QSR paper is attached below as is the paper itself.
In his 1998 paper, Briffa showed that the divergence was largely restricted to the
region covered by the north band described in Cook et al. (2004). Consistent with that
finding, the north ensemble mean shown below reveals a serious downturn in growth after
about 1950. This is an expression of the "divergence" that has been described first by
Briffa and also by D'Arrigo in her NRC talk. In contrast, the south ensemble mean shows
the opposite, i.e. a substantial growth increase which is much more consistent with 20th
century warming. If one than follows the plots back in time, all of the sub-region
ensemble means track each other remarkably well at multi-centennial time scales even
when they enter the putative MWP 800-1000 years ago. In fact, at no time prior to the
20th century is there separation between north and south that is remotely comparable to
that found after ca. 1950. This result suggests that no large-scale "divergence" of the
order found during the 20th century occurred during the MWP even though that period is
suggested to have been somewhat warmer than average overall. This result clearly refutes
the argument that "divergence" of the kind noted in the 20th century happened in the
past. It also suggests a unique anthropogenic cause to the 20th century divergence.
I am not aware of ANY evidence that demonstrates the occurrence of large-scale
"divergence" in the past. It is therefore unjustified to call into question the use of
tree rings for reconstructing temperatures over the past millennium based on a naive
extrapolation of growth "divergence" into the past when it appears to be unique to the
20th century. The NRC committee members must be made aware of this if their report is to
have the necessary scientific credibility that is expected of it.
Sincerely,
Edward R. Cook
References
Briffa, K.R., Schweingruber, F.H., Jones, P.D., Osborn, T.J., Shiyatov, S.G., Vaganov,
E.A. 1998. Reduced sensitivity of recent tree-growth to temperature at high northern
latitudes. Nature 391: 678-682.
Esper, J., Cook, E.R., Schweingruber, F.H. 2002. Low-frequency signals in long tree-ring
chronologies for reconstructing past temperature variability. Science 295: 2250-2253.
Cook, E.R., Esper, J., D'Arrigo, R.D. 2004. Extra-tropical Northern Hemisphere land
temperature variability over the past 1000 years. Quaternary Science Reviews 23(20-22):
2063-2074.
Attachment converted: Macintosh HD:2004_Cook_QSR 1.pdf (PDF /«IC») (0011FEF2)
Attachment converted: Macintosh HD:Cook_QSR_Fig6.gif (GIFf/«IC») (0011FEF5)
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795

References
1. mailto:ikraucunas@nas.edu


Here's the next one
---------------------
Dear Oyvind,
sorry for the delay, I've been off work for a couple of days due to
unexpected family illness.
here are the EPS format figures.  I'll send in separate emails due to
their size.  I've tried to number them correctly according to the new
numbering, though please open them to check they look ok.
One thing to note is that I have separate files for the two panels of
the MWP box figure, and also the forcings/models figure is also in
two files.  They are all labelled appropriately, with the panel part
in the filename, so I hope this is no problem!?
You should get these files:
ipccar4_fig6.10.eps
ipccar4_fig6.11.eps
ipccar4_fig6.12.eps
ipccar4_fig6.13abcd.eps  &  ipccar4_fig6.13e.eps
ipccar4_box6.4_fig1a.eps  &  ipccar4_box6.4_fig1b.eps
Please let me know if they don't all arrive!
Cheers
Tim
At 09:00 08/03/2006, Eystein Jansen wrote:
>Dear Tim and Bette,
>first I wish to thank you again for your particularly outstanding
>and hard work for the SOD. Your work  in particular really has made
>the new draft a lot better than the FOD.
>There is one small remaining issue, however, as noted by the TSU in
>the message posted below. We need high res version, i.e. eps. files
>of your figures. At present we only have the ones sent in word files.
>Could you send the eps. files to us and Øyvind asap so we can get
>the whole delivery uploaded in a finished state to the TSU server.
>Best wishes,
>Eystein
>
>
>
>>Envelope-to: eystein.jansen@geo.uib.no
>>Date: Tue, 07 Mar 2006 19:00:19 -0700
>>From: IPCC-WG1
>>To: Jonathan Overpeck
, eystein.jansen@geo.uib.no
>>Subject: Ch06 Figure Check
>>X-checked-clean: by exiscan on noralf
>>X-UiB-SpamFlag: NO UIB: 0 hits, 8.0 required
>>X-UiB-SpamReport: spamassassin found;
>>
>>
>>Greetings Peck and Eystein!
>>
>>I have gone through the Chapter 6 figure files submitted to the ftp
>>site. Problems with any of the Chapter 6 figures are noted in the
>>attached spreadsheet. Luckily, none of your figures need revision
>>prior to the SOD.
>>
>>However, you will need to provide the TSU with information about
>>the spacing of figures... i.e. one or two columns. Please input
>>that information into the attached spreadsheet and forward that
>>information to the TSU as soon as possible.
>>
>>Another small item: some of your figures were submitted as .pdf
>>files rather than in .eps format. Please note that these files will
>>need to be resubmitted as .eps files in the near future. Although
>>replacing these figures is not urgent, I wanted to let you know now
>>since I know how long it can take to generate high-resolution
>>images. When you do resubmit these files, please be sure to send an
>>email to the TSU to let us know to check the ftp site.
>>
>>If you have any questions, please let me know. Thanks!
>>
>>Regards, Kristen
>>
>>++++++++++++++++++++
>>Kristen Averyt, Ph.D.
>>Project Scientist
>>Intergovernmental Panel on Climate Change
>>Working Group I TSU
>>325 Broadway SDRC CSD08
>>Boulder, CO  80305  USA
>>
>>Tel:  1.303.497.4885
>>Fax: 1.303.497.5686
>>Email: averyt@ucar.edu
>
>
>--
>______________________________________________________________
>Eystein Jansen
>Professor/Director
>Bjerknes Centre for Climate Research and
>Dep. of Earth Science, Univ. of Bergen
>Allégaten 55
>N-5007 Bergen
>NORWAY
>e-mail: eystein.jansen@geo.uib.no
>Phone:  +47-55-583491  -  Home: +47-55-910661
>Fax:    +47-55-584330
>
>#Attachment converted: Øyvind:Ch06_Figure_Check.xls (XLS8/XCEL) (003D0E85)
>
>
>--
>Dr. Øyvind Paasche
>Bjerknes Centre for Climate Research/
>Department of Earth Science
>University of Bergen
>Allé gt. 55
>N-5007, Bergen
>Norway
>Phone direct: +47 55583297
>Cell phone: +47 93048919
>E-mail: oyvind.paasche@bjerknes.uib.no
>
>
>--
>______________________________________________________________
>Eystein Jansen
>Professor/Director
>Bjerknes Centre for Climate Research and
>Dep. of Earth Science, Univ. of Bergen
>Allégaten 55
>N-5007 Bergen
>NORWAY
>e-mail: eystein.jansen@geo.uib.no
>Phone:  +47-55-583491  -  Home: +47-55-910661
>Fax:    +47-55-584330
>
>
>--
>Dr. Øyvind Paasche
>Bjerknes Centre for Climate Research/
>Department of Earth Science
>University of Bergen
>Allé gt. 55
>N-5007, Bergen
>Norway
>Phone direct: +47 55583297
>Cell phone: +47 93048919
>E-mail: oyvind.paasche@bjerknes.uib.no
>
>
>--
>______________________________________________________________
>Eystein Jansen
>Professor/Director
>Bjerknes Centre for Climate Research and
>Dep. of Earth Science, Univ. of Bergen
>Allégaten 55
>N-5007 Bergen
>NORWAY
>e-mail: eystein.jansen@geo.uib.no
>Phone:  +47-55-583491  -  Home: +47-55-910661
>Fax:    +47-55-584330
Attachment Converted: "c:\eudora\attach\ipccar4_fig6.13e.eps"
Dr Timothy J Osborn
Climatic Research Unit
School of Environmental Sciences, University of East Anglia
Norwich  NR4 7TJ, UK
e-mail:   t.osborn@uea.ac.uk
phone:    +44 1603 592089
fax:      +44 1603 507784
web:      ~timo/
sunclock: ~timo/sunclock.htm


Hi Gents, Here is what I just sent off to NRC, cc'd to Gerry North and Bette Otto-Bliesner.
Ed Begin forwarded message: > From: edwardcook > Date: March 15, 2006 7:23:23 PM GMT+07:00
> To: "Kraucunas, Ian" > Cc: edwardcook , g-north@tamu.edu, > ottobli@ucar.edu > Subject:
Comment on NRC Workshop > > Ian Kraucunas, Ph.D. > Board on Atmospheric Sciences and
Climate > National Research Council of The National Academies > 500 Fifth Street NW, Keck
705 > Washington, DC 20001 > > Dear Dr. Kraucunas, > > I request that this document (also
attached as Cook_NRC.pdf) and > the attached scientific paper (2001_Cook_QSR.pdf) be
forwarded to > all NRC committee members who participated in the recent NRC > workshop
"Surface Temperature Reconstructions for the Past 2,000 > Years: Synthesis of Current
Understanding and Challenges for the > Future", ideally with a cc to me when this is done.
I have heard > via emails and telephone conversations about a serious concern > raised
about tree rings by some committee members and invited > participants at the NRC workshop.
This concern could have an > unfairly negative impact on the use of tree rings for >
reconstructing past climate, especially that related to surface air > temperatures, hence
my letter to you and the committee. As part of > her talk, Dr. Rosanne D'Arrigo mentioned
the discovery of > "divergence" between instrumental temperatures and tree growth > during
the last few decades of the 20th century at selected boreal > sites in the Northern
Hemisphere. The affected trees > systematically under-responded to increasing temperatures,
i.e. > they grew more slowly than they should have based on a well-fitted > linear response
model applied to the data prior to the onset of > "divergence". The large-scale occurrence
of this change in > responsiveness has also been described by Keith Briffa (Briffa et >
al., 1998) in Nature. A number of hypotheses have been proposed to > explain it, which
range from natural (climatic change) to > anthropogenic (pollution related), but the actual
cause is still > unknown. This phenomenon needed to be mentioned by Dr. D'Arrigo, > but it
appears to have taken on a level of specious importance that > is not justified by the
evidence. > > Perhaps not surprisingly, but also somewhat alarmingly, it is my >
understanding that some NRC committee members and other influential > participants have
come to the conclusion that the observed 20th > century "divergence" calls into serious
question the value of the > tree-ring reconstructions of temperatures over the past >
millennium. The implicit assumption apparently being made is that > the "divergence" being
caused by environmental conditions in the > 20th century could have also prevailed back
during times like the > Medieval Warm Period (MWP) some 800-1000 years in the past. If >
this were the case, then the concern raised by some at the workshop > would be justified.
However, the available evidence does not > support such a conclusion. In a paper I
published in Quaternary > Science Reviews in 2004 (Cook et al., 2004), I reviewed the >
properties and interpretation of the tree-ring data used in the > Esper et al. (2002) paper
published in Science. The reasonably > well distributed set of tree-ring data in both
boreal and more > temperate latitude sites around the Northern Hemisphere allowed me > to
split up the data into sub-regional ensembles, including 8 sites > in the 55-70Â° north
band and 6 sites in the 30-55Â° south band. > The purpose was to demonstrate the overall
robustness of the multi- > centennial temperature signal in the tree-ring data. This plot >
from the QSR paper is embedded below and the paper is sent being > sent as an attachment.
The importance of this plot to the > "divergence" debate follows next. > > In their paper,
Briffa et al. (1998) showed that the "divergence" > between tree growth and temperatures
was largely restricted to the > region covered by the north band described in Cook et al.
(2004). > Consistent with that finding, the north ensemble mean shown below > (blue curve)
reveals a serious downturn in growth after about > 1950. This is an expression of the
large-scale "divergence" > described by Briffa et al. (1998) and also by Dr. D'Arrigo in
her > NRC talk. In contrast, the south ensemble mean (red curve) shows > the opposite
growth trajectory after 1950, i.e. a substantial > growth increase that is much more
consistent with 20th century > warming. If one then follows the plots back in time, all
sub- > region ensemble means track each other remarkably well at multi- > centennial time
scales even when they enter the putative MWP > 800-1000 years ago. In fact, at no time
prior to the 20th century > is there a separation between north and south that is at all >
comparable to that found after 1950. This result indicates that no > large-scale
"divergence" of the order found during the 20th century > occurred during the MWP even
though that period is suggested to > have been somewhat warmer than average overall. It
thus refutes > the argument that "divergence" of the kind found in the 20th > century could
very well have happened in the past, thus implying > that tree rings cannot produce
reliable reconstructions of past > temperatures. It also supports the existence of an
admittedly > unknown anthropogenic cause of the 20th century "divergence". The > lack of
any known cause is unfortunate, but this would be true > regardless of how the importance
of "divergence" is interpreted. > > I am not aware of ANY evidence that demonstrates the
occurrence of > large-scale "divergence" between tree growth and climate prior to > the
20th century. Indeed, the available evidence indicates just > the opposite. In my opinion
it is therefore unjustified to call > into question the use of tree rings for
reconstructing temperatures > over the past millennium based on a naÃ¯ve and inappropriate
> extrapolation of the growth "divergence" problem into the past when > it appears to be
unique to the 20th century. The NRC committee > members must consider this in their report
if it is to have the > necessary scientific credibility that is expected of it. > >
References > > Briffa, K.R., Schweingruber, F.H., Jones, P.D., Osborn, T.J., > Shiyatov,
S.G., Vaganov, E.A. 1998. Reduced sensitivity of recent > tree-growth to temperature at
high northern latitudes. Nature 391: > 678-682. > > Esper, J., Cook, E.R., Schweingruber,
F.H. 2002. Low-frequency > signals in long tree-ring chronologies for reconstructing past >
temperature variability. Science 295: 2250-2253. > > Cook, E.R., Esper, J., D'Arrigo, R.D.
2004. Extra-tropical Northern > Hemisphere land temperature variability over the past 1000
years. > Quaternary Science Reviews 23(20-22): 2063-2074. > > Sincerely, > > Edward R. Cook
> > ================================== > Dr. Edward R. Cook > Doherty Senior Scholar and >
Director, Tree-Ring Laboratory > Lamont-Doherty Earth Observatory > Palisades, New York
10964 USA > Email: drdendro@ldeo.columbia.edu > Phone: 845-365-8618 > Fax: 845-365-8152 >
================================== > ï¿¼ ï¿¼ ï¿¼ Hi Gents,
Here is what I just sent off to NRC, cc'd to Gerry North and Bette Otto-Bliesner.
Ed
Begin forwarded message:
From: edwardcook
Date: March 15, 2006 7:23:23 PM GMT+07:00
To: "Kraucunas, Ian"
Cc: edwardcook
, [4]g-north@tamu.edu, [5]ottobli@ucar.edu
Subject: Comment on NRC Workshop
Ian Kraucunas, Ph.D.
Board on Atmospheric Sciences and Climate
National Research Council of The National Academies
500 Fifth Street NW, Keck 705
Washington, DC 20001
Dear Dr. Kraucunas,
I request that this document (also attached as Cook_NRC.pdf) and the attached scientific
paper (2001_Cook_QSR.pdf) be forwarded to all NRC committee members who participated in the
recent NRC workshop "Surface Temperature Reconstructions for the Past 2,000 Years:
Synthesis of Current Understanding and Challenges for the Future", ideally with a cc to me
when this is done.  I have heard via emails and telephone conversations about a serious
concern raised about tree rings by some committee members and invited participants at the
NRC workshop.  This concern could have an unfairly negative impact on the use of tree rings
for reconstructing past climate, especially that related to surface air temperatures, hence
my letter to you and the committee.  As part of her talk, Dr. Rosanne D'Arrigo mentioned
the discovery of "divergence" between instrumental temperatures and tree growth during the
last few decades of the 20th century at selected boreal sites in the Northern Hemisphere.
The affected trees systematically under-responded to increasing temperatures, i.e. they
grew more slowly than they should have based on a well-fitted linear response model applied
to the data prior to the onset of "divergence".  The large-scale occurrence of this change
in responsiveness has also been described by Keith Briffa (Briffa et al., 1998) in Nature.
A number of hypotheses have been proposed to explain it, which range from natural (climatic
change) to anthropogenic (pollution related), but the actual cause is still unknown.  This
phenomenon needed to be mentioned by Dr. D'Arrigo, but it appears to have taken on a level
of specious importance that is not justified by the evidence.
Perhaps not surprisingly, but also somewhat alarmingly, it is my understanding that some
NRC committee members and other influential participants have come to the conclusion that
the observed 20th century "divergence" calls into serious question the value of the
tree-ring reconstructions of temperatures over the past millennium.  The implicit
assumption apparently being made is that the "divergence" being caused by environmental
conditions in the 20th century could have also prevailed back during times like the
Medieval Warm Period (MWP) some 800-1000 years in the past.  If this were the case, then
the concern raised by some at the workshop would be justified.  However, the available
evidence does not support such a conclusion.  In a paper I published in Quaternary Science
Reviews in 2004 (Cook et al., 2004), I reviewed the properties and interpretation of the
tree-ring data used in the Esper et al. (2002) paper published in Science.  The reasonably
well distributed set of tree-ring data in both boreal and more temperate latitude sites
around the Northern Hemisphere allowed me to split up the data into sub-regional ensembles,
including 8 sites in the 55-70° north band and 6 sites in the 30-55° south band.  The
purpose was to demonstrate the overall robustness of the multi-centennial temperature
signal in the tree-ring data.  This plot from the QSR paper is embedded below and the paper
is sent being sent as an attachment.  The importance of this plot to the "divergence"
debate follows next.
In their paper, Briffa et al. (1998) showed that the "divergence" between tree growth and
temperatures was largely restricted to the region covered by the north band described in
Cook et al. (2004).  Consistent with that finding, the north ensemble mean shown below
(blue curve) reveals a serious downturn in growth after about 1950.  This is an expression
of the large-scale "divergence" described by Briffa et al. (1998) and also by Dr. D'Arrigo
in her NRC talk.  In contrast, the south ensemble mean (red curve) shows the opposite
growth trajectory after 1950, i.e. a substantial growth increase that is much more
consistent with 20th century warming.  If one then follows the plots back in time, all
sub-region ensemble means track each other remarkably well at multi-centennial time scales
even when they enter the putative MWP 800-1000 years ago.  In fact, at no time prior to the
20th century is there a separation between north and south that is at all comparable to
that found after 1950.  This result indicates that no large-scale "divergence" of the order
found during the 20th century occurred during the MWP even though that period is suggested
to have been somewhat warmer than average overall.  It thus refutes the argument
that "divergence" of the kind found in the 20th century could very well have happened in
the past, thus implying that tree rings cannot produce reliable reconstructions of past
temperatures.  It also supports the existence of an admittedly unknown anthropogenic cause
of the 20th century "divergence".  The lack of any known cause is unfortunate, but this
would be true regardless of how the importance of "divergence" is interpreted.
I am not aware of ANY evidence that demonstrates the occurrence of large-scale "divergence"
between tree growth and climate prior to the 20th century.  Indeed, the available evidence
indicates just the opposite.  In my opinion it is therefore unjustified to call into
question the use of tree rings for reconstructing temperatures over the past millennium
based on a naïve and inappropriate extrapolation of the growth "divergence" problem into
the past when it appears to be unique to the 20th century.  The NRC committee members must
consider this in their report if it is to have the necessary scientific credibility that is
expected of it.
References
Briffa, K.R., Schweingruber, F.H., Jones, P.D., Osborn, T.J., Shiyatov, S.G., Vaganov, E.A.
1998. Reduced sensitivity of recent tree-growth to temperature at high northern latitudes.
Nature 391: 678-682.
Esper, J., Cook, E.R., Schweingruber, F.H. 2002. Low-frequency signals in long tree-ring
chronologies for reconstructing past temperature variability. Science 295: 2250-2253.
Cook, E.R., Esper, J., D'Arrigo, R.D. 2004. Extra-tropical Northern Hemisphere land
temperature variability over the past 1000 years. Quaternary Science Reviews 23(20-22):
2063-2074.
Sincerely,
Edward R. Cook
==================================
Dr. Edward R. Cook
Doherty Senior Scholar and
Director, Tree-Ring Laboratory
Lamont-Doherty Earth Observatory
Palisades, New York 10964  USA
Email:    [6]drdendro@ldeo.columbia.edu
Phone:    845-365-8618
Fax:    845-365-8152
==================================
Attachment Converted: "c:\eudora\attach\2004_Cook_QSR3.pdf"
Attachment Converted: "c:\eudora\attach\Cook_NRC.pdf"
Attachment Converted: "c:\eudora\attach\Cook_QSR_Fig61.gif"
References
1. mailto:drdendro@ldeo.columbia.edu
2. mailto:IKraucunas@nas.edu
3. mailto:drdendro@ldeo.columbia.edu
4. mailto:g-north@tamu.edu
5. mailto:ottobli@ucar.edu
6. mailto:drdendro@ldeo.columbia.edu


Sounds good Martin. Keith, Tim - are you out there? Please help by ensuring we're doing the
right thing w Fig 6.13 and table 6.2
Hi Peck
Thanks for the provisional "go ahead" - we can (and so will) wait till Monday before
changing the master copy of the chapter here.
Regards
Martin
At 11:16 AM 3/23/2006, Jonathan Overpeck wrote:
Hi Martin - this seems ok to me. I hope we hear from Tim and Keith - they are the key
folks on this one. If we don't hear from them, then we go with what you have done. Seems
quite reasonable to me, and I'm sorry we caused the TSU this extra work.
Thanks again, Peck
X-Sieve: CMU Sieve 2.2
Date: Wed, 22 Mar 2006 19:11:36 -0700
To: Jonathan Overpeck
,
Keith Briffa
, t.osborn@uea.ac.uk,
Eystein Jansen
,
,
Bette Otto-Bleisner
,
Melinda Marquis
From: Martin Manning
Subject: Re: SUPER URGENT IPCC help needed
Cc: ssolomon@al.noaa.gov, averyt@ucar.edu
Dear Jonathan
Thanks for trying to sort this out quickly for us and for the information that the
Ammann et al paper is not available.
Susan and I have discussed your two options and have to say that we can not agree to
option 1 in the circumstances. Although the Jones and Mann (2004) paper shows the NCAR
simulation, the key point is that it cites it as "C. Ammann et al private communication
2003". So in effect option 1 would be bringing in material that was not peer reviewed
and not even separately documented. Anyone wanting to discredit your chapter would
highlight the fact that you appear to be depending on work done in 2003 that had still
not been peer-reviewed.
Option 2 is the only way to meet the standard that we have set all along of basing the
assessment very firmly on peer reviewed literature.
Kristen Averyt found that she could edit the EPS files that you had sent us earlier for
Fig 6.13 and take out the curves in question labelled AJS2006. The result is attached.
If you can confirm that this edited figure looks correct we are now proposing to drop
that into your chapter in place of the original one. We would also remove the [S4] row
in Table 6.2 referring to this study. We would also of course use the edited version of
the figure in the TS (Fig TS-26 in current draft).
If you can see any other implications of this approach to resolving the problem that we
need to be aware of please let me know.  If the author team wants to provide a redrawn
figure that might be an improvement on the attached version we can still wait until
Monday morning for that.
Best regards
Martin
At 04:25 PM 3/22/2006, Jonathan Overpeck wrote:
Hi Keith and Tim - need FAST help. Figure 6.13, and Table 6.2 cite Amman et al., for the
CSM curve. Since this paper doesn't yet exist in "in press" form (I checked w/ Bette,
who is a co-author), we have two choices. I think choice one below could be ok, but want
to have confirmation from Keith or Tim, and it it's not ok, (NOTE) Tim and Keith need to
get new Fig and Table to Melinda and Martin at the TSU by Monday.
Option 1: we can cite Jones, P.D., and M.E. Mann, 2004: Climate over past millennia.
Reviews of Geophysics, 42(2) - this paper (already in references - there is hope!) has
the CSM simulation in its Fig 8, but of course it's not the idea original reference
describing the simulation.
Option 2: we (Tim) creates new fig 6.13, and Table 6.2 without any reference to this
simulation.
PLEASE NOTE - if Keith and Tim (or Martin) feels we must go w/ option 2, Tim has to send
the new fig and table to TSU (Melinda Marguis and Martin) by Monday AM at the absolute
latest.
Thanks for your quick help, Peck
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795

--
Recommended Email address: mmanning@al.noaa.gov
** Please note that problems may occur with my @noaa.gov address
Dr Martin R Manning, Director, IPCC WG I Support Unit
NOAA Aeronomy Laboratory                        Phone: +1 303 497 4479
325 Broadway, DSRC R/AL8          Fax: +1 303 497 5628
Boulder, CO 80305, USA
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795

--
Recommended Email address: mmanning@al.noaa.gov
** Please note that problems may occur with my @noaa.gov address
Dr Martin R Manning, Director, IPCC WG I Support Unit
NOAA Aeronomy Laboratory                        Phone: +1 303 497 4479
325 Broadway, DSRC R/AL8          Fax: +1 303 497 5628
Boulder, CO 80305, USA
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795


Dear all,
we (Keith and I) agree that it isn't appropriate to cite only Jones
and Mann (2004) as a reference for the NCAR CSM curves in figure 6.13.
Another alternative to deleting the curves, however, would be to
reference Mann, Rutherford, Wahl and Ammann (2005), which should
already be in the reference list.  This might be an appropriate
reference because it includes Ammann as a co-author and provides a
more information about the simulation than Jones and Mann
(2004).  However it still relies upon the submitted Ammann et al.
paper as the main reference -- so maybe still not good enough?  I've
attached a PDF of Mann et al. (2005) for you to consider.
From earlier discussions (and perhaps also in relation to chapters
using new model runs of future climate), I thought that a new
unpublished run with an existing published model under published
forcing might be allowed (in the same way that updated 2005 or 2006
instrumental temperatures could be included, even if not published,
providing they were compiled following the procedures described in an
earlier paper).  For instance, the EMIC runs we included as an extra
panel probably fall in this category.  Maybe the CSM run falls in
this category too?  Have other runs with this model been
published?  And the forcing used in this run was presented in Goosse
et al. (2005; GRL 32, L06710, again it includes Ammann as a
co-author) as well as in Jones and Mann (2004).  So, maybe CSM can be
included under this reasoning?
I don't want to sound as if we are arguing strenuously to keep the
CSM curves in the figure -- if the preferred decision is to drop it,
then so be it.  If so, then the modified figure looks ok.
Cheers
Tim
At 02:11 23/03/2006, Martin Manning wrote:
>Dear Jonathan
>
>Thanks for trying to sort this out quickly for us and for the
>information that the Ammann et al paper is not available.
>
>Susan and I have discussed your two options and have to say that we
>can not agree to option 1 in the circumstances. Although the Jones
>and Mann (2004) paper shows the NCAR simulation, the key point is
>that it cites it as "C. Ammann et al private communication 2003". So
>in effect option 1 would be bringing in material that was not peer
>reviewed and not even separately documented. Anyone wanting to
>discredit your chapter would highlight the fact that you appear to
>be depending on work done in 2003 that had still not been peer-reviewed.
>
>Option 2 is the only way to meet the standard that we have set all
>along of basing the assessment very firmly on peer reviewed literature.
>
>Kristen Averyt found that she could edit the EPS files that you had
>sent us earlier for Fig 6.13 and take out the curves in question
>labelled AJS2006. The result is attached.
>
>If you can confirm that this edited figure looks correct we are now
>proposing to drop that into your chapter in place of the original
>one. We would also remove the [S4] row in Table 6.2 referring to
>this study. We would also of course use the edited version of the
>figure in the TS (Fig TS-26 in current draft).
>
>If you can see any other implications of this approach to resolving
>the problem that we need to be aware of please let me know.  If the
>author team wants to provide a redrawn figure that might be an
>improvement on the attached version we can still wait until Monday
>morning for that.
>
>Best regards
>Martin
>
>At 04:25 PM 3/22/2006, Jonathan Overpeck wrote:
>>Hi Keith and Tim - need FAST help. Figure 6.13, and Table 6.2 cite
>>Amman et al., for the CSM curve. Since this paper doesn't yet exist
>>in "in press" form (I checked w/ Bette, who is a co-author), we
>>have two choices. I think choice one below could be ok, but want to
>>have confirmation from Keith or Tim, and it it's not ok, (NOTE) Tim
>>and Keith need to get new Fig and Table to Melinda and Martin at
>>the TSU by Monday.
>>
>>Option 1: we can cite Jones, P.D., and M.E. Mann, 2004: Climate
>>over past millennia. Reviews of Geophysics, 42(2) - this paper
>>(already in references - there is hope!) has the CSM simulation in
>>its Fig 8, but of course it's not the idea original reference
>>describing the simulation.
>>
>>Option 2: we (Tim) creates new fig 6.13, and Table 6.2 without any
>>reference to this simulation.
>>
>>PLEASE NOTE - if Keith and Tim (or Martin) feels we must go w/
>>option 2, Tim has to send the new fig and table to TSU (Melinda
>>Marguis and Martin) by Monday AM at the absolute latest.
>>
>>Thanks for your quick help, Peck
>>
>>
>>--
>>
>>Jonathan T. Overpeck
>>Director, Institute for the Study of Planet Earth
>>Professor, Department of Geosciences
>>Professor, Department of Atmospheric Sciences
>>
>>Mail and Fedex Address:
>>
>>Institute for the Study of Planet Earth
>>715 N. Park Ave. 2nd Floor
>>University of Arizona
>>Tucson, AZ 85721
>>direct tel: +1 520 622-9065
>>fax: +1 520 792-8795
>>
>
>--
>Recommended Email address: mmanning@al.noaa.gov
>** Please note that problems may occur with my @noaa.gov address
>Dr Martin R Manning, Director, IPCC WG I Support Unit
>NOAA Aeronomy Laboratory                        Phone: +1 303 497 4479
>325 Broadway, DSRC R/AL8                Fax: +1 303 497 5628
>Boulder, CO 80305, USA
Attachment Converted: "c:\eudora\attach\mann 2005 pseudoproxy.pdf"
Dr Timothy J Osborn
Climatic Research Unit
School of Environmental Sciences, University of East Anglia
Norwich  NR4 7TJ, UK
e-mail:   t.osborn@uea.ac.uk
phone:    +44 1603 592089
fax:      +44 1603 507784
web:      ~timo/
sunclock: ~timo/sunclock.htm


Dear Diane / Mike / NRC Committee,
At 22:18 28/03/2006, Gustafson, Diane wrote:
>Dear Tim:
>
>Our National Research Council Committee on Surface Temperature
>Reconstructions has been considering your paper with Keith Briffa
>published in a recent issue of Science.  Could you please elaborate
>on your criterion for selecting the proxy time series included in
>the analysis.  We are interested in how you computed the correlation
>between the proxy time series and local temperature time series.  Is
>the correlation based on filtered or detrended time series?  How
>would you counter the potential criticism that your selection method
>tends to favor proxy time series that show a strong 20th century warming?
>
>It would be most helpful for us if you could reply in time for us to
>consider your response at our meeting tomorrow morning.  Thanks in
>advance for your help.
>
>Mike Wallace
We (Tim Osborn and Keith Briffa) will first respond to these specific
questions about our recent Science paper.  In addition, copied below
are some further comments by Keith Briffa on issues related to
tree-ring proxy records, that may be of interest to the committee.
The primary purpose of our paper was to implement an alternative, and
possibly complementary, method of proxy-data analysis to the methods
used in most previously published reconstructions of past NH
temperature variations.  We did not want to introduce an entirely new
selection of proxy records (even if this were possible), because that
would obscure whether differences in our conclusions, compared with
published work, arose from our method or a different selection of
proxy records.
We decided, therefore, to make use of as many of the individual
records used in almost all the previously published NH temperature
reconstructions, excluding any records for which an indication of at
least partial temperature sensitivity was lacking.  So, very low
resolution records for which comparison with instrumental
temperatures is problematic were excluded.
We used records specifically from Mann and Jones (2003) and Esper et
al. (2002).  In addition we included records from Mann et al. (2003),
which I think just adds the van Engelen documentary record from the
Low Countries in Europe, because the others were already in the Mann
and Jones set.  We excluded duplicates, and our paper explains which
series we used where duplicates were present.  We did not average the
Tornetrask, Yamal and Taimyr tree-ring records as done by Mann and
Jones, because we could see no reason not to use them as individual series.
The series used by Mann and Jones had already been correlated with
their local instrumental temperatures -- using decadally-smoothed,
non-detrended, values -- so we accepted this as an indication of some
temperature sensitivity.  For the other series, we calculated our own
correlations against local instrumental temperatures, trying both
annual-mean or summer-mean temperatures.  In our paper's
supplementary information, we state that we used the HadCRUT2
temperatures for this purpose, which combines land air temperatures
with SST observations.  In fact, we used the CRUTEM2 land-only
temperature data set for this purpose.  These should be identical
where the proxy locations are not coastal.  For these correlations,
we did not filter the data, nor did we detrend it, and we used the
*full* period of overlap between the proxy record and the available
instrumental record.
We excluded records that did not show a *positive* correlation with
their local temperatures.  The remaining set includes most of the
long, high resolution records used by others, such as Moberg et al.,
Crowley and Lowery, Hegerl et al., Mann, Bradley and Hughes, etc. as
well as by Mann and Jones and Esper et al.
The final question, regarding the selection method favouring records
that show a strong 20th century warming trend, is a more
philosophical issue.  As stated above, we did not actually use
strongly selective criteria, preferring to use those records that
others had previously used and only eliminating those that were
clearly lacking in temperature sensitivity.  To some extent,
therefore, the question is then directed towards the studies whose
selection of data we used.  Certainly we did not look through a whole
host of possibilities and just pick those with a strong upward trend
in the last century!  And we don't think the scientists whose work we
selected from would have done this either.  There are very few series
to choose from that are >500 years long and are from proxy
types/locations where temperature sensitivity might be expected.  It
would be entirely the wrong impression to think that there are 140
such a priori suitable possible series, and that we picked (either
explicitly or implicitly) just those 10% that happened by chance to
exhibit upward 20th century trends.
The correlation with local temperature is an entirely appropriate
factor to consider when selecting data; these could be computed using
detrended data, though for those that we calculated, our use of
unfiltered data means that the trend is unlikely to dominate the
correlation.  One would need to inspect the trend in the temperature
data at each location to evaluate how much influence it would have on
the results; but in locations where a strong upward trend is present,
it would be right to exclude proxy records that did not reproduce it,
though also correct that a proxy shouldn't be included solely on the
basis of it having the trend, especially where the proxy resolution
is sufficient to test its ability to capture shorter term fluctuations.
Finally, note that our method has not selected only those records
with a strong 20th century warming trend.  Of the 14 proxies selected
(see our figure 1), 7(!) do not have strong upward 20th century
trends: Quebec, Chesapeake Bay, W Greenland, Tirol, Tornetrask,
Mangazeja, and Taimyr.  Our method gives equal weight to all records,
so it should not be biased towards a single record, or a small number
of records, that do show strong upward trends.
Here are the additional comments on tree-ring issues:
I would also like to take the opportunity, if you will allow, to
comment briefly on some reports that have reached me concerning the
contribution made by Rosanne D'Arrigo to your Committee. Apparently,
this is being interpreted by some as reflecting adversely on the
validity of numerous temperature reconstructions that involve
significant dependence on tree-ring data. This is related to
Rosanne's focus in her presentation on the apparent difference
between measured temperatures and tree growth in recent decades  - a
so-called "divergence" problem.
First let me make it clear that as I did not attend the Committee
meeting I am not able to comment specifically on the details of
Rosanne D'Arrigo's actual presentation, though I am aware of her
papers with various co-authors related to this "divergence" in the
recent (circa post 1970 ) trends in tree-growth and temperature
changes as recorded in instrumental data, at near tree-line sites in
the Canadian Arctic. There are also other papers dealing with
'changing growth responses' to climate in North American trees.
I have co-authored a paper in Nature on the reduced response to
warming as seen in tree-ring densitometric data at high-latitude
sites around the Northern Hemisphere, increasingly apparent in the
last 30 years or so.
First, it is important to note that the phenomena is complicated
because it is not clearly identifiable as a ubiquitous problem.
Rather it is a mix of possible regionally distinct indications, a
possible mix of phenomena that is almost certainly in part due to the
methodological aspects of the way tree-ring series are produced. This
applies to my own work, but also very likely to other work.
The implications at this stage for the 'hockey stick' and other
reconstructions are not great. That is because virtually all long
tree-ring reconstructions that contribute to the various
reconstructions, are NOT affected by this. Most show good coherence
with temperature at local levels in recent decades. This is not true
for one series (based on the density data). As these are our data, I
am able to say that initial unpublished work will show that the
"problem" can be mitigated with the use of new, and again
unpublished, chronology construction methods.
In the case of the work by Rosanne and colleagues, I offer my
educated opinion that the phenomenon they describe is likely also, at
least in part, a chronology construction issue. I am not saying that
this is a full explanation, and certainly there is the possibility of
increased moisture stress on these trees, but at present the issue is
still being defined and explored. As the issue needs more work, this
is only an opinion, and until there is peer-reviewed and published
evidence as to the degree of methodological uncertainty , it is not
appropriate to criticize this or other work . For my part, I have
been very busy, lately with teaching and IPCC commitments, but we
will do some work on this now, though again lack of funds to support
a research assistant do not help.
The matter is important but I do not believe that the facts yet
support Rosanne's contention, in her Global Biogeochemical Cycles
paper (Vol. 18, GB3021, doi:10.1029/2004GB002249, 2004) that an
optimum physiological threshold has been consistently exceeded at a
site in the Yukon. This conclusion should certainly not be taken as
indicating a widespread threshold exceedence.
It was my call not to "overplay" the importance of the divergence
issue, knowing the subtlety of the issues, in the fortcoming IPCC
Chapter 6 draft. We did always intend to have a brief section about
the assumption of uniformitarianism in proxy interpretation ,
including mention of the possible direct carbon dioxide fertilization
effect on tree growth (equally controversial), but it is likely to
conclude that here as well , there is no strong evidence of any major
real-world effect. This and the divergence problem are not well
defined, sufficiently studied,  or quantified to be worthy of too
much concern at this point. The uncertainty estimates we calibrate
when interpreting many tree-ring series will likely incorporate the
possibility of some bias in our estimates of past warmth, but these
are wide anyway. This does not mean that temperatures were
necessarily at the upper extreme of the reconstruction uncertainty
range 1000 years ago, any more than they may have been at the bottom.
The real problem is a lack of widespread (and non-terrestrial)
proxies for defining the level of early warmth, and the vital need to
up-date and study the responses of proxies in very recent times.
Best regards,
Tim Osborn and Keith Briffa
--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593909
Fax: +44-1603-507784

Dr Timothy J Osborn
Climatic Research Unit
School of Environmental Sciences, University of East Anglia
Norwich  NR4 7TJ, UK
e-mail:   t.osborn@uea.ac.uk
phone:    +44 1603 592089
fax:      +44 1603 507784
web:      ~timo/
sunclock: ~timo/sunclock.htm


Tim,
yes, I also found it strange. We noticed that Amman and Wahl cited their Science comment as
accepted in their manuscript that is now in press in Climatic Change.
Personally I think it is convenient that this clarification gets published but I am
somewhat disapointed by the fact that a very similar content was submitted by Buerger and
Cubasch about one year ago and it was not even sent to reviewers (it is the paper
that finally appeared in Tellus).  I think that comment was of much higher quality than WahlÂ´s.
Science knew of the Tellus paper, since we cite it in our response. So actually
there is scientifically nothing new in this exchange, but it will be published in Science...
Anyway, I am happy to have more time now for more productive work and hope that Ritson
doe not bomb me with more mails in the future
eduardo
> Thanks for letting us know, Eduardo.  It is strange that Science
> accepted the Wahl et al. comment before yours; we were told of this
> on 28-Feb and that is why you will notice, if you get to see the
> latest IPCC draft, that Wahl et al. is cited but your response is not
> cited!  This will look strange, given that they will be published
> together.  Maybe it can be changed later?
>
> Cheers
>
> Tim
>
> At 11:31 29/03/2006, Eduardo Zorita wrote:
> >Dear Tim,
> >
> >the comment by Wahl, Ritson and Amman and our response have been now
> >accepted for
> >publication in Science
> >
> >eduardo
>
> Dr Timothy J Osborn
> Climatic Research Unit
> School of Environmental Sciences, University of East Anglia
> Norwich  NR4 7TJ, UK
>
> e-mail:   t.osborn@uea.ac.uk
> phone:    +44 1603 592089
> fax:      +44 1603 507784
> web:      ~timo/
> sunclock: ~timo/sunclock.htm
>


Dear Brooks Hanson,
of the two additional questions/requests, the first one is quick to
respond to and so I can do that immediately.
In fact my previous reply answers the first question already, as does
our paper itself in a very clear way.  It is something of a waste of
time, therefore, to have to write another answer, but here goes anyway...
We clearly state (in the SOM to our paper) what the data sources
were, and Esper et al. was not the source for the four series in
question.  There is, therefore, no need for anyone to "surmise" that
this is the case, because we explicitly state it!
Further, we state in our paragraph (d) that we replaced Athabasca
with a new, "better-replicated series" from Luckman and
Wilson.  "Better-replicated" clearly indicates that there are more
data in the new series than were available to Esper et al., as is
also clear from even a cursory read of the Luckman and Wilson
paper.  So it should be obvious that you cannot expect to reproduce
the results using the fuller data set by using only the more limited
data available from Esper et al. -- otherwise what would be the point
of going out and collecting all that new data?
The other three series are covered in our paragraph (c), "The data
sets contain some non-identical tree-ring series derived from the
same sites; we have favoured series from (S3) because they are based
on a greater number of tree core measurements than the series
generated by (S1)".  So we clearly did not use the Esper et al. data
(S1) and it should also be clear that the series we did use can not
be reproduced using the Esper et al. data because they are
"non-identical" and there are fewer tree cores in the Esper et al.
data.  The source we gave for these three series is Briffa (2000).
We did not use tree-core measurement data in our paper, only
chronologies that had previously been assembled by others from core
measurement data.  I don't have any core measurement data and
therefore have none to give out!  And in my first reply I explained
why I didn't think that this was appropriate anyway, since I consider
that our obligation is limited to providing data to allow the
replication of the steps reported in our paper, none of which
involved any processing of core measurement data.
I will reply next week regarding the second question/request.
Best regards
Tim
At 20:35 30/03/2006, Brooks Hanson wrote:
>  Dear Dr. Osborn:
>
>Thank you for your assistance in resolving the request for data for
>your recent paper.  I have passed along the relevant information you
>have provided (I assure you not your email).  In response, i've received
>two additional questions.  I'm wondering if it would be possible to
>clarify these.
>
>In 4 cases, the Osborn site chronology differs from the Esper site
>chronology, although in the other cases the versions are identical. In
>some cases, the date ranges do not match. I do not believe that it is
>possible to replicate the Osborn version from the Esper measurement data
>in these 4 cases and surmise that Osborn used a different measurement
>data set. I therefore request measurement data used by Osborn for the
>following sites: Polar Urals, Tornetrrask, Taymir and Athabaska.
>
>The HadCRU2 data set contains temperature data for the gridcell 37.5N,
>117.5W commencing in 1870. However, the gridcell information provided
>by Osborn commenced only in 1888 and the differences are material to
>the final result (0.045 versus 0.18 reported). What is the reason for
>commencing this comparison in 1888 rather than the available 1870? Since
>there is a material difference in this example, could you please provide
>the gridcell temperature sets in a comparable format for the other 13
>Osborn and Briffa series
>
>I appreciate that the latter request may take some additional effort as
>you noted.  I'm hopeful that this will provide a resolution to this
>matter.
>
>Sincerely,
>Brooks Hanson
Dr Timothy J Osborn
Climatic Research Unit
School of Environmental Sciences, University of East Anglia
Norwich  NR4 7TJ, UK
e-mail:   t.osborn@uea.ac.uk
phone:    +44 1603 592089
fax:      +44 1603 507784
web:      ~timo/
sunclock: ~timo/sunclock.htm


At 18:17 03/04/2006, you wrote:
>Hi Rainer, we drafted a complaint, which  Keith Briffa still sits on, and
>I don´t think it will be sent. Some of our partners, e.g. Hadley Centre,
>MPI and CNRS were reluctant as they thought complaining might backfire.
>If there was foul play, we had no proof of it. We did some checks with
>commission representatives, but did not learn much. I think the problem
>was that the review panel was biased against us, and that the commission
>did not follow up with instructions that was coherent with their own policies.
>
>Best wishes,
>Eystein
Hi Eystein,
not sure if I comprehend the mentality of not sending a statement, keeping
a low profile I do not perceive a good strategy. I am mentioning this as I
have become increasingly weary of FWP programmes and proposals. Over the
past four years I was involved in 4 initiatives none of which came through.
Beyond the immediate frustration on the basis of the individual failures I
do note in all these instances is an unfavourable degree of ambiguity in
the reviewing process such that it appears the reviewers are being kept in
the dark about the vision of the call beyond what the call says in
printing. I can see the challenge from the programme managerial side that
one wishes not to interfere with the reviewing progress and yet I feel that
the reviews offered, perhaps the reviewing process at large, do not live up
to the standards set for proposals. Quite frankly, from my few
conversations I had with the programme managers and their assistants I have
come to the conclusion that they are helpful in providing assistance with
logistics and proposal structuring, yet on a managerial front they are not
up to speed with what I would perceive professionalism in handling their
tasks.  So to me it seems there are various levels involved in the issue
that in the end mount to the impression that FWPs are not an immediate
option for proposals much longer. This view is shared by quite a number of
colleagues and it is for this reason that I am convince we must respond to
the Imprint failing.
If Keith doesn't mind perhaps forward the statement so I can glance through
it.
Best,    Rainer


Hi Henry - thanks for the email. Just earlier
today, Eystein and I were soliciting approval
from our team on how to best get feedback from
chapter authors - Lead Authors and Contributing
Authors alike. Since we're all authors, it isn't
appropriate to comment officially as expert
reviewers, but rather to work as a team to take
expert reviews - AND chapter 6 author feedback -
and use them to create a better finalo draft. One
key, as promised earlier, is to have a process
that makes sure we get all comments and are able
to respond to them. The other key is that we
ensure time to allow the needed debate. Eystein
and I are going to ask LAs (including Keith) to
do there work sooner in the draft cycle than
before so that we have the time for this.
So... I would suggest you keep these comments in
a safe place for a bit longer, and then send them
in to the Eystein and I when we ask (should be in
the next week). Note that the current draft has
only officially been available for a bit over a
week (indeed, I didn't see it until today since
the IPCC TSU had to check for all sorts of things
after we submitted it over a month ago), and we
won't be working on the new draft until June. So
we have time to be thoughtful and complete in the
feedback gathering process.
Is this ok? Seems more suitable than giving
review via the gov process on your own work (you
are an author of our chapter).
Also, I can anticipate one thing that is going to
come up again, and that I don't think we had your
feedback on (nor Keith's). What about the
borehole recons that you and colleagues have done
extending back beyond the last couple centuries.
I don't have my paper pdf collection here, but I
believe you have some recons going back many
centuries. Does this need more attention in the
chapter?
Thanks for being proactive and quick to send
feedback. We'll be sending our email to all CA's
soon, if you're willing to wait a couple more
days.
Thanks, peck
>Hi Keith (and Peck and Eystein),
>
>I have recently been sent the current draft of the IPCC FAR by the US
>Global Change Research Program, asking for comments on the draft. This
>is the first time I have seen this product since we were feverishly
>exchanging e-mails in February. Let me call to your attention some
>small but not insignificant corrections to be made to the next draft.
>
>Page 6-33, Section 6.6.1.2, line 22.  The title of this section (in
>italics) should be changed to "What do ground surface temperature
>reconstructions derived from subsurface temperature measurements tell
>us?"
>
>Page 6-33, lines 49 and 52, there is a reference (Smerdon et al., in press).
>This paper has now been published, so substitute "2006" for "in press",
>and in the list of references the citation should include the following:
>
>J. Geophys. Res. 111, D07101, doi:10.1029/2004JD005578
>
>Page 6-34, lines 43 and 44. This section is dealing with the southern
>hemisphere. The sentence "...these both indicate unusually warm
>conditions prevailing in the 20th century (Pollack and Smerdon, 2004)"
>, and the reference therein, are both incorrect.
>
>The ground surface temperature changes over the last 500 years DO NOT
>indicate unusually warm conditions prevailing in the 20th century in
>Australia and southern Africa. This is because the unusually warm
>conditions developed late in the century, after most of the boreholes
>had already been logged.  What the borehole reconstruction for
>Australia does show is very good correspondence with the Cook et al
>(2000) reconstruction for Tasmania and the Cook et al. (2002) recon for
>New Zealand. The Australia work is described in a manuscript “Five
>centuries of Climate Change in Australia: The View from Underground” by
>Pollack, Huang and Smerdon now under review in the Journal of
>Quaternary Science. The Africa work is unpublished.
>
>Is this e-mail to you sufficient to activate these changes? Or should I
>submit these comments to the US Government Review Panel? If I am to
>submit to the latter, they require all comments to be filed by May 9.
>
>Cheers,
>Henry
>
>
>  ___    ___    Henry N. Pollack
>[   \  /   ]   Professor of Geophysics
>  |   \/   |    Department of Geological Sciences
>  |MICHIGAN|    University of Michigan
>[___]\/[___]   Ann Arbor, Michigan 48109-1005, U.S.A.
>
>  Phone: 734-763-0084   FAX: 734-763-4690
>  e-mail: hpollack@umich.edu
>  URL:  www.geo.lsa.umich.edu/~hpollack/
>  URL:  www-personal.umich.edu/~hpollack/book.html
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795


thanks Tim,
I'm saddened to hear that this bozo is bothering you too, in addition to
NCAR, NSF, NAS, IPCC and everyone else. Rest assured that I  won't ever
respond to McIntyre should he ever contact me, but I will forward you
any email he sends related to this. I assume Scott feels the same way...
I hope you're having as nice a spring as we are here. See you in June?
mike
p.s. we have some interesting new reconstructionbased on RegEM using a
greatly expanded multiproxy network (which includes the MXD data).  I
hope to send you guys shortly. It is our hope that you'll consider being
co-authors. This to come soon...
Tim Osborn wrote:
> Hi Scott and Mike,
>
> as lead author and co-author on the Rutherford et al. paper, I thought
> I'd let you know that we are dealing with some requests for the MXD
> data set used in this paper, including the one copied below from
> McIntyre.  We should have got this organised a bit quicker but we will
> (eventually!) get the data and its description available for
> interested parties.  So if you get any more requests for the MXD data
> that were used in our joint paper, please pass them on to me.
>
> Hope everything's well with you,
>
> Tim
>
>
>> Date: Wed, 26 Apr 2006 15:08:39 +0100
>> To: "Steve McIntyre"
>> From: Tim Osborn
>> Subject: Re: Ruherford et al 2005
>> Cc: "Andrew Weaver"
, Keith Briffa
>>
>> Dear Steve,
>>
>> I have just finished responding to Science about your latest request
>> to them concerning our recent paper, so I can now turn to your
>> request copied below.
>>
>> I can answer your first request immediately:
>>
>> The MXD data used in Rutherford et al. were *derived* from the
>> Schweingruber network, but aren't actually the raw site-by-site data
>> values.  The reason why we didn't use the latter is that the
>> site-by-site MXD chronologies have only been processed using a
>> "traditional" approach to standardization that removes low-frequency
>> climate variations.  Our age-band decomposition approach (Briffa et
>> al., 2001, JGR), which retains more low-frequency variability, had
>> only been applied at the regional-average level.  So we gridded the
>> site-by-site chronologies onto a 5x5 grid and added to each grid box
>> the "missing" regional-scale low-frequency information identified by
>> comparing the age-band and traditionally-standardized results at a
>> regional scale.
>>
>> I will respond with information and/or data to your requests (2)-(4)
>> soon.
>>
>> Regards
>>
>> Tim
>>
>> At 19:37 18/04/2006, Steve McIntyre wrote:
>>
>>> Dear Tim, I presume that the sites used in the MXD network in
>>> Rutherford et al., Journal of Climate 2005 came from the
>>> SChweingruber network. Could you provide me with (1) confirmation as
>>> to whether this is the case; (2) identification of the sites; (3)
>>> the protocol for site selection from the larger Schweingruber
>>> network; (4) a URL for any data or dataversions not available in the
>>> Schweingruber network at WDCP.  Regards, Steve McIntyre
>>
>
> Dr Timothy J Osborn
> Climatic Research Unit
> School of Environmental Sciences, University of East Anglia
> Norwich  NR4 7TJ, UK
>
> e-mail:   t.osborn@uea.ac.uk
> phone:    +44 1603 592089
> fax:      +44 1603 507784
> web:      ~timo/
> sunclock: ~timo/sunclock.htm
>
--
Michael E. Mann
Associate Professor
Director, Earth System Science Center (ESSC)
Department of Meteorology              Phone: (814) 863-4075
503 Walker Building                    FAX:   (814) 865-3663
The Pennsylvania State University      email:  mann@psu.edu
University Park, PA 16802-5013


X-Mailer: QUALCOMM Windows Eudora Version 7.0.0.16
Date: Fri, 28 Apr 2006 15:08:05 +0100
To: philip.brohan@metoffice.gov.uk
From: Tim Osborn
Subject: Re: Standardisation uncertainty for tree-ring series
Cc: Keith Briffa
,simon.tett@metoffice.gov.uk
Hi Philip,
we have three "groups" of trees:
"SCAND" (which includes the Tornetrask and Finland multi-millennial chronologies, but
also some shorter chronologies from the same region).  These trees fall mainly within
the 3 boxes centred at:
17.5E, 67.5N
22.5E, 67.5N
27.5E, 67.5N
"URALS" (which includes the Yamal and Polar Urals long chronologies, plus other shorter
ones).  These fall mainly within these 3 boxes:
52.5E, 67.5N
62.5E, 62.5N (note this is the only one not at 67.5N)
67.5E, 67.5N
"TAIMYR" (which includes the Taimyr long chronology, plus other shorter ones).  These
fall mainly within these 4 boxes:
87.5E, 67.5N
102.5E, 67.5N
112.5E, 67.5N
122.5E, 67.5N
We do some analysis at the group scale, and for this we take the JJA temperatures from
each box and average to the group scale to obtain a single series from each of SCAND,
URALS and TAIMY.
We do some analysis at the overall scale, and for this we take these three group
temperature series and average them to get an overall NW Eurasia temperature for boxes
with tree chronologies in them.
We did also try using a wider average for the region, including all LAND temperatures
from grid boxes within a rectangular region from 12.5E to 127.5E and from 57.5N to
72.5N, but I don't think it correlated so well against the tree-ring width data (I can't
remember the exact correlations), so we didn't pursue that.
Does that give you enough information to be going on with?  I'd recommend using CRUTEM3
rather than HadCRUT3, because the correlations seem to deteriorate with the inclusion of
SST data in some cases -- though of course you can look into this yourself.
Cheers
Tim
At 16:35 27/04/2006, philip.brohan@metoffice.gov.uk wrote:
Thanks Tim.
I need to extract from the instrumental and model data the appropriate
data to calibrate the tree-rings against. Presumably this is the
June-July-August average land surface temperature for a particular
region in NW Eurasia. Could you send me the lat and long ranges of the
region?
Cheers,
Philip
On Thu, 2006-04-27 at 16:01, Tim Osborn wrote:
> Thanks for the nice precise description of methodology, Philip.  It's
> good that we are all clear exactly what procedure is to be applied.
>
> On the train after our meeting last week, Keith and I discussed this
> a bit more.  In the NW Eurasian case study, n is quite high and
> therefore it is likely that the bootstrap estimates will show
> relatively little variation and probably will underestimate the true
> error (due to additional errors in the assumptions underlying RCS, as
> discussed in London).  We will do the calculations anyway, and then
> we will know for sure how large/small they are, rather than just speculating.
>
> It looks likely that Tom Melvin will have time to devote directly to
> this issue as he will probably be funded by our (that includes you,
> Simon) NERC RAPID project for a while.  Once/if this is confirmed,
> then we'll get Tom to do the calculations outlined below and
> communicate directly with Philip over any implementation issues etc.
>
> Cheers
>
> Tim
>
> At 16:02 26/04/2006, philip.brohan@metoffice.gov.uk wrote:
> >Keith, Tim.
> >
> >  At our meeting last Wednesday I agreed to specify exactly what needed
> >to be done to make uncertainty estimates for standardisation of the
> >tree-ring data.
> >
> >  Suppose we are making a proxy series from n cores. From those n cores
> >we can make an RCS age correction curve, and a mean proxy series (the
> >average of the cores after applying the age correction curve to each
> >one?). These are the best-estimate values for the age-correction curve
> >and the proxy series.
> >
> >  We also need bootstrap estimates of the age correction curve and the
> >mean proxy series. To make a bootstrap estimate: sample, with
> >replacement, from the n cores until you have a set of n samples. (Some
> >of the cores will be in this sample once, some several times, and some
> >not at all). From this set of n samples, make an age correction curve
> >and a mean proxy series as before. These are the bootstrap estimates.
> >
> >  We need a lot of bootstrap estimates. I'd like 1000 - 100 will probably
> >do at a pinch. So please can you make these and send me the 1001 age
> >correction curves and 1001 mean proxy series.
> >
> >  I will do something similar with the instrumental series, and we can
> >then make bootstrap estimates of the regression uncertainty and the
> >uncertainty in the reconstructed temperatures.
> >
> >Cheers,
> >
> >  Philip
> >
> >--
> >Philip Brohan,  Climate Scientist
> >Met Office   Hadley Centre for Climate Prediction and Research
> >Tel: +44 (0)1392 884574    Fax: +44 (0)1392 885681
> >Global climate data sets are available from [1]
>
> Dr Timothy J Osborn
> Climatic Research Unit
> School of Environmental Sciences, University of East Anglia
> Norwich  NR4 7TJ, UK
>
> e-mail:   t.osborn@uea.ac.uk
> phone:    +44 1603 592089
> fax:      +44 1603 507784
> web:      [2]~timo/
> sunclock: [3]~timo/sunclock.htm
--
Philip Brohan,  Climate Scientist
Met Office   Hadley Centre for Climate Prediction and Research
Tel: +44 (0)1392 884574    Fax: +44 (0)1392 885681
Global climate data sets are available from [4]
Dr Timothy J Osborn
Climatic Research Unit
School of Environmental Sciences, University of East Anglia
Norwich  NR4 7TJ, UK
e-mail:   t.osborn@uea.ac.uk
phone:    +44 1603 592089
fax:      +44 1603 507784
web:      [5]~timo/
sunclock: [6]~timo/sunclock.htm
--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593909
Fax: +44-1603-507784
[7]
References
1.
2. ~timo/
3. ~timo/sunclock.htm
4.
5. ~timo/
6. ~timo/sunclock.htm
7.


Dear  Tim, dear Keith,
I am writing to inform you that I have reconsidered my acceptance to attend
the Wengen meeting. In the last days I have  convinced myself  that under the present circumstances
a constructive discussion on reconstruction methods is unfortunately not  possible.
We have another exchange on the last Journal of Climate paper by Mann et al, which is now under review. Even the editor of J. of Climate found adequate to tell us that all inflammatory comments in their response would have to be eventually deleted.
Even considering the considerable pressure that he has is
exposed to in American politics, I think Michael Mann is unable of any constructive discussion.
I am very grateful for your invitation to this meeting and I hope that we can continue our collaboration in other ocasion.
Best wishes
eduardo


hi tim. personally, I don't see why you should make any concessions for this moron. By the way, our supplementary site (now on scott's computer) doesn't block any ip#s. another lie.. Mike
-----Original Message-----
From:  Tim Osborn
Subj:  FW: Ruherford et al 2005
Date:  Fri May 12, 2006 8:10 am
Size:  4K
To:  Keith Briffa
, "Phil Jones"
,        "Michael E. Mann"
,        Scott Rutherford
Thought you might be interested in the following.  I *am* going to
provide the list of MXD sites requested, but honestly haven't had
time to put it together this his request.  Clearly the 2-week delay
was too long for him!  Still, at least I'm not (yet) described as
"juvenile"! :-)
Tim
>From: "Steve McIntyre"
>To: "Andrew Weaver"
>Cc: "Tim Osborn"
>Subject: FW: Ruherford et al 2005
>Date: Fri, 12 May 2006 09:54:37 -0400
>
>Dear Andrew,
>Rutherford et al 2005 states that supplementary information is available at
>~rutherfo/supplements/jclim2003a.
>
>First, in passing, Scott Rutherford has blocked the IP address of the
>computer that I regularly use from access to that site (I had previously
>been blocked from Mann's FTP site.) While I have been able to have someone
>else send me the data, I'm sure that such petty behavior is inconsistent
>with Journal of Climate access policies and I request that you ask your
>authors to stop such juvenile behavior insofar as it affects the Journal of
>Climate.
>
>Second, the referenced website does NOT contain the MXD data, but only
>includes a link to "Ask Tim Osborn". As you can see from the attached
>correspondence, Osborn has undertaken to provide the requested information,
>but the article certainly implies - and I am sure that that this was your
>understanding as editor - that the data would be readily available. In this
>case, even a simple listing of the sites has not been provided after nearly
>2 weeks. (I might add that I initially requested a listing of the sites from
>a coauthor nearly 2 years ago.)
>
>In order to comply with the apparent undertakings of Rutherford et al, I
>think that you should arrange for a less ad hoc method of providing the
>supplementary information.
>
>Regards,
>
>Steve McIntyre
>
>
>
>
>
>-----Original Message-----
>From: Tim Osborn
>Sent: April 26, 2006 10:09 AM
>To: Steve McIntyre
>Cc: Andrew Weaver; Keith Briffa
>Subject: Re: Ruherford et al 2005
>
>
>Dear Steve,
>
>I have just finished responding to Science about your latest request
>to them concerning our recent paper, so I can now turn to your
>request copied below.
>
>I can answer your first request immediately:
>
>The MXD data used in Rutherford et al. were *derived* from the
>Schweingruber network, but aren't actually the raw site-by-site data
>values.  The reason why we didn't use the latter is that the
>site-by-site MXD chronologies have only been processed using a
>"traditional" approach to standardization that removes low-frequency
>climate variations.  Our age-band decomposition approach (Briffa et
>al., 2001, JGR), which retains more low-frequency variability, had
>only been applied at the regional-average level.  So we gridded the
>site-by-site chronologies onto a 5x5 grid and added to each grid box
>the "missing" regional-scale low-frequency information identified by
>comparing the age-band and traditionally-standardized results at a
>regional scale.
>
>I will respond with information and/or data to your requests (2)-(4) soon.
>
>Regards
>
>Tim
>
>At 19:37 18/04/2006, Steve McIntyre wrote:
> >Dear Tim, I presume that the sites used in the MXD network in
> >Rutherford et al., Journal of Climate 2005 came from the
> >SChweingruber network. Could you provide me with (1) confirmation as
> >to whether this is the case; (2) identification of the sites; (3)
> >the protocol for site selection from the larger Schweingruber
> >network; (4) a URL for any data or dataversions not available in the
> >Schweingruber network at WDCP.  Regards, Steve McIntyre
>
>Dr Timothy J Osborn
>Climatic Research Unit
>School of Environmental Sciences, University of East Anglia
>Norwich  NR4 7TJ, UK
>
>e-mail:   t.osborn@uea.ac.uk
>phone:    +44 1603 592089
>fax:      +44 1603 507784
>web:      ~timo/
>sunclock: ~timo/sunclock.htm
Dr Timothy J Osborn
Climatic Research Unit
School of Environmental Sciences, University of East Anglia
Norwich  NR4 7TJ, UK
e-mail:   t.osborn@uea.ac.uk
phone:    +44 1603 592089
fax:      +44 1603 507784
web:      ~timo/
sunclock: ~timo/sunclock.htm


Hi Neil - Thanks for your interest in providing feedback on the draft
chap 6 Second Order Draft. Since the IPCC has very strict rules about
all this, I'm going to ask them (the IPCC) to send you an official
invitation to review, along with the process - formal, but highly
efficient - to follow. If you could send your comments in that way it
would be a great help. We've been asked to keep everything squeaky
clean, and not to get comments informally.
Thanks! Peck
>Dear Jonathan
>
>Please excuse me for writing direct, but Keith Briffa suggested it
>would be simplest. I have looked through the draft chapter 6 and
>find it an impressive document. However, bullet 4 on page 6.2,
>starting "global mean cooling and warming....." strikes me as
>incorrect and misleading.
>
>Whereas the mean rate of temperature change over the Pleistocene may
>have been >10 times slower than that projected for the next century,
>there is clear evidence that for specific major climatic
>transitions, global (or at least hemispheric) temperature changes in
>the past have been at least as rapid as those projected by climate
>model simulations and incorporated in the last IPCC report.  The
>most obvious case in point is the global warming at the start of the
>Holocene, ca. 11.5 ka BP. Russell Coope, more than 20 years ago,
>showed from beetles that UK temperatures rose faster than could be
>dated within the errors of 14C dating. Subsequently this was
>confirmed by Greeland ice cores based on layer counting (full
>glacial to interglacial in less than 100 years), and by the Cariacos
>basin marine record. I have worked on varved lake records from both
>the tropics (Roberts et al Nature 1993 366, 146-148) and the
>Mediterranean (Roberts et al The Holocene, 2001, 11, 719-734) where
>this climate transition was accomplished in substantially less than
>a century.  In short, several independent lines of evidence show
>that the climate system has been capable of flipping from one
>meta-stable state to another, very different one over timescales
>that could be experienced by a single human lifetime.  This is not
>an unimportant conclusion in terms of the potential for non-linear
>responses of future climate to GHG forcing.
>
>I also looked for supporting argument for bullet 4 later in chapter
>6, but found nothing of substance.
>
>In short, this particular bullet seems in need of critical
>reassessment before the definitive version of the next IPCC reprot
>emerges.
>
>Thanks in anticipation and best egards
>
>Neil
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795


Hi Gene - thanks for the update. If Tim/Keith/Caspar want to add
anything (or Martin ask for more clarification), please cc to the
entire list on this email. Sounds like the UCAR version is the one to
consider "official" (right everyone?).
Thanks again, Peck
>Hello Peck, Martin, Bette, Eystein, Caspar:
>
>I just double checked the UCAR website version with the pdf version
>I have, and they are identical with the exception that the
>supplemental tables (Tables 1S and 2S), and supplemental figure
>caption and figure (Figure 1S) are placed at the very end of the
>document in the UCAR version.  The content is identical in both
>versions.
>
>The text (including tables and figure captions) of the UCAR pdf is
>also identical to the WORD text that I sent to Peck, Keith Briffa,
>and Eyestein Jansen on February 24.  There was a version sent on
>February 21, which the February 24 version superceded.  There were 3
>words changed on p. 17, and some changes made to Appendix 1 in the
>February 24 version.  Perhaps this difference between the 2/21 and
>2/24 versions is the cause of the differences that Martin has seen.
>[Note:  I would have sent the graphics separately with these
>versions, and I did not keep copies of the sent files in my email
>account -- to deal with memory limits in the system here.  Thus, I
>cannot confirm exactly which graphic files are associated with the
>February 24 version.  My apologies.]
>
>In summary, the UCAR website pdf document should be considered the
>official one that is "accepted/in press".  Formal notification of
>acceptance from Stephen Schneider at Climatic Change came on
>February 28.  The article is still in this status.
>
>Let me know if I can help clarify things futher.  Please note that I
>will be in Boulder starting May 27, to be a visiting scholar at NCAR
>for a month.  I will be keeping up with email from there.
>
>
>Peace, Gene
>Dr. Eugene R. Wahl
>Asst. Professor of Environmental Studies
>Alfred University
>
>607-871-2604
>1 Saxon Drive
>Alfred, NY 14802
>________________________________
>
>From: Jonathan Overpeck
>Sent: Sat 5/20/2006 8:39 PM
>To: Martin Manning
>Cc: Bette Otto-Bleisner; Eystein Jansen; Caspar Ammann; Wahl, Eugene R
>Subject: Re: Wahl & Amman paper
>
>Hi Martin - We'll look into this asap. I'll cc to Caspar and Gene to
>see if they can clarify the situation and make sure we have the
>correct version. I'll also cc Bette since she may see Caspar around
>NCAR and make sure he know's we are trying to clarify things with
>his paper.
>
>More soon, thx, Peck
>
>
>	Dear Eystein and Jonathan
>
>	It has been pointed out to us by a reviewer that the version
>of the Wahl and Amman paper (accepted by Climatic Change) on our
>review web site differs from the version that is available publicly
>from the NCAR web site at:
>
>
>	[
>
>
>
>	]
>
>
>	Although the differences are not (in my view) substantial,
>the paper on the NCAR web site is apparently dated Feb 24th (i.e.
>before the date of final submission of the SOD), it has additional
>figures and data, and the running header says "Feb 24, .... in
>press".
>
>	Could you please clarify which of the two versions of this
>paper would reflect most accurately the status of the paper as used
>by the Chapter 6 team when preparing the SOD. That has been our
>basis for deciding on which version to include on our reviewer web
>pages up until now, but we are now reconsidering whether to also
>include updated versions of unpublished papers as well. If you have
>any thoughts on that please let me know.
>
>	Best regards
>	Martin
>
>
>	--
>	Recommended Email address: mmanning@al.noaa.gov
>	** Please note that problems may occur with my @noaa.gov address
>	Dr Martin R Manning, Director, IPCC WG I Support Unit
>	NOAA Aeronomy Laboratory                        Phone: +1 303 497 4479
>	325 Broadway, DSRC R/CSD8         Fax: +1 303 497 5628
>	Boulder, CO 80305, USA
>
>
>
>--
>Jonathan T. Overpeck
>Director, Institute for the Study of Planet Earth
>Professor, Department of Geosciences
>Professor, Department of Atmospheric Sciences
>
>Mail and Fedex Address:
>
>Institute for the Study of Planet Earth
>715 N. Park Ave. 2nd Floor
>University of Arizona
>Tucson, AZ 85721
>direct tel: +1 520 622-9065
>fax: +1 520 792-8795
>
>
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795


Thanks all who have commented. Below is the likely final word unless
Martin needs more clarification. Seem ok, Martin? Sorry for the
confusion. Guess some reviewers are running out of substantive
issues, so that might be a sign that we're getting close to the final
draft...
Best, Peck
From Caspar:
>Dear all, yes the UCAR version can be considered the "official" one.
>I changed the order of pages because I needed to separate the
>"primary content" of the paper from its "supplement"; thus I moved
>tables xS, figure 1S and its caption to the end. Everything else is
>identical.
From Keith:
"the differences are as I understand , insubstantial and not
pertinent to the interpretation used in preparing the draft."
and Gene:
>
>Wahl, Eugene R wrote:
>>Hello Peck, Martin, Bette, Eystein, Caspar:
>>  I just double checked the UCAR website version with the pdf
>>version I have, and they are identical with the exception that the
>>supplemental tables (Tables 1S and 2S), and supplemental figure
>>caption and figure (Figure 1S) are placed at the very end of the
>>document in the UCAR version.  The content is identical in both
>>versions.
>>  The text (including tables and figure captions) of the UCAR pdf is
>>also identical to the WORD text that I sent to Peck, Keith Briffa,
>>and Eyestein Jansen on February 24.  There was a version sent on
>>February 21, which the February 24 version superceded.  There were
>>3 words changed on p. 17, and some changes made to Appendix 1 in
>>the February 24 version.  Perhaps this difference between the 2/21
>>and 2/24 versions is the cause of the differences that Martin has
>>seen.  [Note:  I would have sent the graphics separately with these
>>versions, and I did not keep copies of the sent files in my email
>>account -- to deal with memory limits in the system here.  Thus, I
>>cannot confirm exactly which graphic files are associated with the
>>February 24 version.  My apologies.]
>>  In summary, the UCAR website pdf document should be considered the
>>official one that is "accepted/in press".  Formal notification of
>>acceptance from Stephen Schneider at Climatic Change came on
>>February 28.  The article is still in this status.
>>  Let me know if I can help clarify things futher.  Please note that
>>I will be in Boulder starting May 27, to be a visiting scholar at
>>NCAR for a month.  I will be keeping up with email from there.
>>   Peace, Gene Dr. Eugene R. Wahl
>>Asst. Professor of Environmental Studies
>>Alfred University
>>  607-871-2604
>>1 Saxon Drive
>>Alfred, NY 14802 ________________________________
>>
>>From: Jonathan Overpeck
>>Sent: Sat 5/20/2006 8:39 PM
>>To: Martin Manning
>>Cc: Bette Otto-Bleisner; Eystein Jansen; Caspar Ammann; Wahl, Eugene R
>>Subject: Re: Wahl & Amman paper
>>
>>Hi Martin - We'll look into this asap. I'll cc to Caspar and Gene
>>to see if they can clarify the situation and make sure we have the
>>correct version. I'll also cc Bette since she may see Caspar around
>>NCAR and make sure he know's we are trying to clarify things with
>>his paper.
>>
>>More soon, thx, Peck
>>
>>
>>	Dear Eystein and Jonathan
>>
>>	It has been pointed out to us by a reviewer that the version
>>of the Wahl and Amman paper (accepted by Climatic Change) on our
>>review web site differs from the version that is available publicly
>>from the NCAR web site at:
>>
>>
>>	[
>>
>>
>>
>>	]
>>
>>
>>	Although the differences are not (in my view) substantial,
>>the paper on the NCAR web site is apparently dated Feb 24th (i.e.
>>before the date of final submission of the SOD), it has additional
>>figures and data, and the running header says "Feb 24, .... in
>>press".
>>
>>	Could you please clarify which of the two versions of this
>>paper would reflect most accurately the status of the paper as used
>>by the Chapter 6 team when preparing the SOD. That has been our
>>basis for deciding on which version to include on our reviewer web
>>pages up until now, but we are now reconsidering whether to also
>>include updated versions of unpublished papers as well. If you have
>>any thoughts on that please let me know.
>>
>>	Best regards
>>	Martin
>>
>>
>>	--
>>	Recommended Email address: mmanning@al.noaa.gov
>>	** Please note that problems may occur with my @noaa.gov address
>>	Dr Martin R Manning, Director, IPCC WG I Support Unit
>>	NOAA Aeronomy Laboratory                        Phone: +1 303 497 4479
>>	325 Broadway, DSRC R/CSD8         Fax: +1 303 497 5628
>>	Boulder, CO 80305, USA
>>
>>
>>
>
>--
>Caspar M. Ammann
>National Center for Atmospheric Research
>Climate and Global Dynamics Division - Paleoclimatology
>1850 Table Mesa Drive
>Boulder, CO 80307-3000
>email: ammann@ucar.edu    tel: 303-497-1705     fax: 303-497-1348
--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences
Mail and Fedex Address:
Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795