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Mike
Tim and I have discussed this round and round and our response is attached
what do you think
best wishes Keith
At 17:33 10/10/2006, you wrote:
>Dear Tim/Keith,
>
>I hope all is well with both of you.
>
>We've been doing a number of sensitivity tests w/ RegEM using both
>the CSM simulation, and now more recently the GKSS simulation data
>we got from you. There are some methodological developments we'll
>describe soon, related to what is the most reliable regularization
>method in RegEM, ridge regression and truncated total least squares.
>We are now leaning towards the latter because of potential
>non-convergence problems in some cases w/ the former. More on that soon.
>
>More relevant, however, are the results. As you can see from the
>attached plot, RegEM works quite well w/ GKSS, using a short
>calibration period (1900-1980, corresponding to years 900-980 in the
>attached plot) and both white and red pseudoproxy noise (we used
>rho=0.5 in the attached, but similar result for other values).
>
>The most interesting result is that while RegEM reconstructs the
>full NH series well throughout, in the case of the CSM simulation,
>it does modestly underestimate the warmth of the earliest centuries
>in  the GKSS Erik simulation (it fits everything else, including the
>LIA cooling, very well). We feel that this is likely due to problem
>of correctly identifying the 'drift' pattern using CFR methods.
>
>The long and short of this is that we would like to be able to show
>this result in a (very short!) J. Climate response we need to
>finalize, to a comment on Mann et al (2005) J. Clim by Zorita and
>Von Storch. We would show you this response for comment of course,
>and would add you as co-authors. We have cleared with Andrew Weaver
>that this would be an acceptable course of action.  We are hoping
>you are in agreement with this?
>
>please let us know ASAP, we have to finalize our response within days.
>
>thanks,
>
>mike
>
>--
>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
>
>
>
>
>
>
--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593909
Fax: +44-1603-507784

Attachment Converted: "c:\documents and settings\tim osborn\my documents\eudora\attach\letter to Mike  - 131.10.06.doc"


Mike
Tim and I have discussed this round and round and our response is attached
what do you think
best wishes Keith
At 17:33 10/10/2006, you wrote:
Dear Tim/Keith,
I hope all is well with both of you.
We've been doing a number of sensitivity tests w/ RegEM using both the CSM simulation,
and now more recently the GKSS simulation data we got from you. There are some
methodological developments we'll describe soon, related to what is the most reliable
regularization method in RegEM, ridge regression and truncated total least squares. We
are now leaning towards the latter because of potential non-convergence problems in some
cases w/ the former. More on that soon.
More relevant, however, are the results. As you can see from the attached plot, RegEM
works quite well w/ GKSS, using a short calibration period (1900-1980, corresponding to
years 900-980 in the attached plot) and both white and red pseudoproxy noise (we used
rho=0.5 in the attached, but similar result for other values).
The most interesting result is that while RegEM reconstructs the full NH series well
throughout, in the case of the CSM simulation, it does modestly underestimate the warmth
of the earliest centuries in  the GKSS Erik simulation (it fits everything else,
including the LIA cooling, very well). We feel that this is likely due to problem of
correctly identifying the 'drift' pattern using CFR methods.
The long and short of this is that we would like to be able to show this result in a
(very short!) J. Climate response we need to finalize, to a comment on Mann et al (2005)
J. Clim by Zorita and Von Storch. We would show you this response for comment of course,
and would add you as co-authors. We have cleared with Andrew Weaver that this would be
an acceptable course of action.  We are hoping you are in agreement with this?
please let us know ASAP, we have to finalize our response within days.
thanks,
mike
--
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
[1]
--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593909
Fax: +44-1603-507784
[2]
References
1.
2.


"
>> >X-UEA-Spam-Score: -102.8
>> >X-UEA-Spam-Level: ---------------------------------------------------
>> >X-UEA-Spam-Flag: NO
>> >X-Virus-Scanned: amavisd-sophos
>> >X-PSU-Spam-Flag: NO
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>> >
>> >Mike
>> >Tim and I have discussed this round and round and our response is
>> attached
>> >
>> >what do you think
>> >
>> >best wishes Keith
>> >
>> >At 17:33 10/10/2006, you wrote:
>> >>Dear Tim/Keith,
>> >>
>> >>I hope all is well with both of you.
>> >>
>> >>We've been doing a number of sensitivity tests w/ RegEM using both
>> >>the CSM simulation, and now more recently the GKSS simulation data
>> >>we got from you. There are some methodological developments we'll
>> >>describe soon, related to what is the most reliable regularization
>> >>method in RegEM, ridge regression and truncated total least
>> >>squares. We are now leaning towards the latter because of potential
>> >>non-convergence problems in some cases w/ the former. More on that
>> soon.
>> >>
>> >>More relevant, however, are the results. As you can see from the
>> >>attached plot, RegEM works quite well w/ GKSS, using a short
>> >>calibration period (1900-1980, corresponding to years 900-980 in
>> >>the attached plot) and both white and red pseudoproxy noise (we
>> >>used rho=0.5 in the attached, but similar result for other values).
>> >>
>> >>The most interesting result is that while RegEM reconstructs the
>> >>full NH series well throughout, in the case of the CSM simulation,
>> >>it does modestly underestimate the warmth of the earliest centuries
>> >>in  the GKSS Erik simulation (it fits everything else, including
>> >>the LIA cooling, very well). We feel that this is likely due to
>> >>problem of correctly identifying the 'drift' pattern using CFR
>> methods.
>> >>
>> >>The long and short of this is that we would like to be able to show
>> >>this result in a (very short!) J. Climate response we need to
>> >>finalize, to a comment on Mann et al (2005) J. Clim by Zorita and
>> >>Von Storch. We would show you this response for comment of course,
>> >>and would add you as co-authors. We have cleared with Andrew Weaver
>> >>that this would be an acceptable course of action.  We are hoping
>> >>you are in agreement with this?
>> >>
>> >>please let us know ASAP, we have to finalize our response within days.
>> >>
>> >>thanks,
>> >>
>> >>mike
>> >>
>> >>--
>> >>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
>> >>
>> >>
>> >>
>> >>
>> >>
>> >
>> >--
>> >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, Academic Fellow
>> 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
>
>
> --
> Professor Keith Briffa,
> Climatic Research Unit
> University of East Anglia
> Norwich, NR4 7TJ, U.K.
>
> Phone: +44-1603-593909
> Fax: +44-1603-507784
>
>
--
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


Martin
This last point is likely true  (though CO2 began to rise earlier than the 1960s and the
authors of the original paper believed that the  high elevation (and concomitant low CO2
partial pressure) may have amplified the response to small concentration changes. There is
also the possibility that a synergistic increase in water-use (and possibly nitrogen use)
efficiency could have contributed .
However,  I agree that the rapid growth increase is most likely a result of a change in the
proportion of net photosynthetic production potential (ie needle mass) relative to the area
of living cambium that could occur as a tree shifts from "normal" to strip bark form .If
this changes suddenly , as growth occurs only along a small strip rather than around the
whole circumference (I know this is oversimplified) then you could easily get this apparent
change in growth rate . BUT , if this is seen synchronously in many trees it would be hard
to believe that this was the cause. To look at this would require a detail examination of
all the data (in relation to the precise sample geometry) . Changing precipitation trends ,
such as occurred pre- and post the mid 1970s will also  confuse things .
Thanks Jan and Rob also for this discussion.
At 17:14 16/11/2006, Keith Briffa wrote:
To: Martin Juckes
From: Keith Briffa
Subject: Re: Mitrie: Bristlecones
In-Reply-To:
References:
This last point is likely true  (though CO2 began to rise earlier than the 1960s and the
authors of the original paper believed that the  high elevation (and concomitant low CO2
partial pressure) may have amplified the response to small concentration changes. There
is also the - and I agree that the rapid growth increase is most likely a result of the
proportion of net photosynthetic production potential (ie needle mass) relative to the
area of living cambium .If this changes suddenly , as growth occurs only along a small
strip rather than around the whole circumference (I know this is oversimplified) then
you could easily get this apparent change in growth rate . To look at this would require
a detail examination of all the data (in relation to the precise sample geometry) .
However, changing precipitation trends pre- and post the mid 1970s will also  confuse
things .At 16:41 16/11/2006, you wrote:
Thanks for all those comments.
I'm trying to avoid omitting data on the basis of cicrumstantial evidence,
even when it is presented enthusiastically. The Bunn et al. study is
interesting (attached) because they show estimated dates of the onset of
strip-bark growth. It looks to me as though the growth anomaly of the
strip-bark trees relative to the others is more to do with this change than
anything else. The onset of a positive growth anomaly in the 1850s is
certainly too early to be associated with CO2 increases.
cheers,
Martin
On Thursday 16 November 2006 14:51, Rob Wilson wrote:
> Re: Mitrie: BristleconesDear All,
> For the D'Arrigo et al. 2006 paper, I did indeed consider using the
Bristlecone pine data.
> However, due to the issues raised by Macintyre and others, we felt that it
would be unwise to use these data, especially as our data-set was biased more
to higher latitudes.
>
> However, I did look at the data. I do not like ignoring potential data-sets.
>
> Of the BP data that I managed to get my hands on, I identified a
significant, but relatively weak, correlation with local gridded mean summer
temperatures for three sites. These three sites are: Hermit Hill (N = 38;
1048-1983) and Windy Ridge (N = 29; 1050-1985) from Colorado and Sheep
Mountain (N = 71; 0 - 1990) from California.
>
> The attached figure compares the RCS chronology using these data (very
similar to the STD version in actual fact) with the North American RCS
composite series used in D'Arrigo et al. (2006). Both series have been
normalised to the 1200-1750 period to highlight any potential differences in
the 20th century.
>
> There is generally fairly good coherence between the two series between 1100
and the 1900. I personally do not think we have enough sites prior to 1400,
so the lack of coherence prior to 1100 might just reflect regional
differences and not enough series to derive a meaningful mean function.
Although correlation with gridded temperatures are relatively low (~0.40),
the coherence with the NA composite would seem to suggest that temperature is
the dominant signal over the last 900 years or so.
>
> In the 20th century, the BP index values are clearly UNDER the NA mean. I
would interpret this as suggesting that there does not appear to be any CO2
influence in the BP data. This of course assumes that there is no
fertilisation effect in the rest of the NA data.
>
> There is also the Salzer BP based temperature reconstruction:
> [1]
>
> again this does not correlate particular well with gridded temperatures - in
fact it is driven more by trends, but there are some similarities with my BP
chronology and NA series.
>
> I hope this helps the discussion
> best regards
> Rob
>
>   ----- Original Message -----
>   From: Jan Esper
>   To: Keith Briffa ; Martin Juckes ; Myles Allen
>   Cc: anders@misu.su.se ; Eduardo.Zorita@gkss.de ; hegerl@duke.edu ;
weber@knmi.nl ; t.osborn@uea.ac.uk ; Wilson Rob
>   Sent: Thursday, November 16, 2006 1:36 PM
>   Subject: Re: Mitrie: Bristlecones
>
>
>   ...no, no, not a lot to add from my side. This is much more than I could
have said. Except, I once looked at strip bark growth trees in Central Asia,
and at least there the cause for this growth form was clear to me (Esper
2000, The Holocene):
>
>
>   "Strip-bark growth forms (Ferguson, 1968; Fritts, 1969; Graybill and Idso,
1993; Kelly et al., 1992; Wright and Mooney, 1965) also appear in older
Juniper trees. This condition develops as the cambium is damaged locally and
will no longer be overgrown. Mechanical damage by rockfall seems to be the
principle stimulus for cambial dieback and unilateral growth. In extreme
cases only a narrow strip on the stem is still active, creating these
eccentric growth forms."
>
>
>   I didn't visit the Bristlecone sites yet, but the mechanism might be the
same (some physical damage).
>
>
>   I believe that over time the crown and root system are reduced, but not at
the same rate than the reduction in circumference covered by the cambium.
This would be the key for strip bark tree rings being wider than "normal"
rings.
>
>
>   I am not very convinced that there are long-term fertilization effects by
CO2 (but have of course no proof for this). As far as I know, (most) results
from free air CO2 enrichment experiments suggest that there is no long-term
effect.
>
>
>   I Cc Rob Wilson to the mail, as he might have looked at Bristlecone data
recently. Pehaps he wants to add something.
>
>
>   Best --je
>
>
>   At 11:57 Uhr +0000 16.11.2006, Keith Briffa wrote:
>     Martin and all,
>     I know Franco very well - but he has not worked extensively with the
Bristlecones. I still believe that it  would be wise to involve Malcolm
Hughes in this discussion - though I recognise the point of view that says we
might like to appear (and be) independent of the original Mann, Bradley and
Hughes team to avoid the appearance of collusion. In my opinion (as someone
how has worked with the Bristlecone data hardly at all!) there are
undoubtedly problems in their use that go beyond the strip bark problem (that
I will come back to later).
>     The main one is an ambiguity in the nature and consistency of their
sensitivity to temperature variations. It was widely believed some 2-3
decades ago, that high-elevation trees were PREDOMINANTLY responding to
temperature and low elevation ones  to available water supply (not always
related in a simple way to measured precipitation) . However, response
functions ( ie sets of regression coefficients on monthly mean temperature
and precipitation data derived using principal components regression applied
to the tree-ring data) have always shown quite weak and temporally unstable
associations between chronology and climate variations (for the
high-elevations trees at least). The trouble is that these results are
dominated by inter-annual (ie high-frequency) variations and apparent
instability in the relationships is exacerbated by the shortness of the
instrumental records that restrict analyses to short periods, and the large
separation of the climate station records from the sites of the trees.
Limited comparisons between tree-ring density data (which seem to display
less ambiguos responses) imply that there is a reasonable decadal time scale
association and so indicate a real temperature signal , on this time
scale .The bottom line though is that these trees likely represent a mixed
temperature and moisture-supply response that might vary on longer
timescales.
>     The discussion is further complicated by the fact that the first PC of
"Western US" trees used in the Mann et al. analyses is derived from a mixture
of species (not just Bristlecones ) and they are quite varied in their
characteristics , time span, and effective variance spectra . Many show low
interannual variance and a long-term declining trend , up until about 1850 ,
when the Bristlecones (and others) show the remarkable increasing trend up
until the end of the record. The earlier negative trend could be (partly or
more significantly) a consequence of the LACK of detrending to allow for age
effects in the measurements (ie standardisation) - the very early sections of
relative high growth were removed in their analysis, but no explicit
standardistion of the data was made to account for remaining slow width
changes resulting from tree aging.  This is also related to the "strip bark"
problem , as these types of trees will have unpredictable trends as a
consequence of aging  and depending on the precise nature of each tree's
structure .
>      Another serious issue to be considered relates to the fact that the PC1
time series in the Mann et al. analysis was  adjusted to reduce the positive
slope in the last 150 years (on the assumption - following an earlier paper
by Lamarche et al. - that this incressing growth was evidence of carbon
dioxide fertilization) , by differencing the data from another record
produced by other workers in  northern Alaska and Canada (which  incidentally
was standardised in a totally different way). This last adjustment obviously
will have a large influence on the quantification of the link between these
Western US trees and N.Hemisphere temperatures. At this point , it is fair to
say that this adjustment was arbitrary and the link between Bristlecone pine
growth and CO2 is , at the very least, arguable. Note that at least one
author (Lisa Gaumlich) has stated that the recent growth of these trees could
be temperature driven and not evidence of CO2 fertilisation.
>
>     The point of this message is to show that that this issue is complex ,
and I still believe the "Western US" series and its interpretation in terms
of Hemispheric mean temperature is perhaps a "Pandora's box" that we might
open at our peril!
>     What does Jan say about this - he is very acquainted with these issues?
>
>     cheers
>     Keith
>     At 15:01 15/11/2006, Martin Juckes wrote:
>       Hi,
>
>       Concerning Bristlecones, I had a sympathetic reply from Prof. North,
but he
>       deferred to the person who wrote the relevant paragraph in the NAS
report
>       (Franco Biondi) who is firmly of the view that strip-bark bristlecones
should
>       not be used. I've read a few of the articles cited to back up this
statement
>       and I am surprised by the extreme weakness of the evidence. There is
one
>       study of 27 strip-bark pines which shows that they clearly developed
>       anomalous growth around 1850. Attributing this to CO2 is odd, to say
the
>       least. I'm writing a brief review of the literature which I'll send
round in
>       a few days time.
>
>       cheers,
>       Martin
>
>       On Sunday 12 November 2006 22:21, Myles Allen wrote:
>       > Although it probably doesn't feel like it, it seems to me you're
doing
>       > rather well...
>       >
>       > -----Original Message-----
>       > From: Martin Juckes [[2]mailto:m.n.juckes@rl.ac.uk]
>       > Sent: 10 November 2006 15:24
>       > To: anders@misu.su.se; Eduardo.Zorita@gkss.de; hegerl@duke.edu;
>       > esper@wsl.ch; k.briffa@uea.ac.uk; Myles Allen; weber@knmi.nl;
>       > t.osborn@uea.ac.uk
>       > Subject: Mitrie
>       >
>       > Hello,
>       >
>       > well, I've had a few exchanges on climateaudit, and decided to leave
>       > them to
>       > it for a few days.
>       >
>       > I'm going to send an email to Prof. North of the NAS panel to ask if
he
>       > really
>       > meant "don't use bristlecones", as he is quoted by McIntyre. I
believe
>       > it
>       > would be incorrect to select sites on the basis of what the data
from
>       > the
>       > sites looks like, and this makes up a substantial part of the
argument
>       > in
>       > Graybill and Idso (1993).
>       >
>       > Does anyone know where I can get hold of the categorisation of the
Sheep
>       >
>       > Mountain trees used by Graybill and Idso (ca534.rwl from the WDC for
>       > paleoclimatology I think) into "strip-bark" and "full-bark"? I've
sent
>       > an
>       > email to the WDC query address.
>       >
>       > I've also sent of for a publication which is cited by co2science as
>       > using
>       > Sargasso Sea data with the dating shifted by 50 years (Loehle,
2004,
>       > Ecological Modelling). This appears to be a source of considerable
>       > confusion
>       > among the climate sceptics. The shifted series fits nicely with the
idea
>       > that
>       > the Medieval Warm Period was warmer than the 20th century, so there
is a
>       >
>       > widespread perception that it is being ignored to fudge the results.
>       >
>       > Apart from a couple of oversights in the documentation of the data
files
>       >
>       > McIntyre hasn't come up with much yet. I need to read up a bit more
on
>       > the
>       > different Tornetraesk/Fennoscandia series.  There was an interesting
>       > discussion on "cherrypicking", with contributors suggesting that
testing
>       > the
>       > effect of removing each proxy series in turn was "cherrypicking" and
>       > that
>       > selecting series based on subjective analysis of what the series
look
>       > like
>       > would be much better!
>       >
>       > I've had a comment from the editor saying that responses to
non-refereee
>       >
>       > comments are optional, especially if the comments are not relevant
to
>       > the
>       > paper.
>       >
>       > cheers,
>       > Martin
>       >
>       >
>       >
>
>     --
>     Professor Keith Briffa,
>     Climatic Research Unit
>     University of East Anglia
>     Norwich, NR4 7TJ, U.K.
>
>     Phone: +44-1603-593909
>     Fax: +44-1603-507784
>
>     [3]
>
>
>
>
> --
> PD Dr. Jan Esper
>   Swiss Federal Research Institute WSL
>   Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
>   Voice: +41-44-739 2510
>   Fax:   +41-44-739 2515
>   [4]
--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593909
Fax: +44-1603-507784
[5]
--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593909
Fax: +44-1603-507784
[6]
References
1.
2. mailto:m.n.juckes@rl.ac.uk
3.
4.
5.
6.


ï»¿
Morning Martin,
It might be worth taking Keith's advice and contacting Malcolm Hughes.
I am not convinced that the Bunn study is fully relevant to addressing the use of BP data
from Colorado and California as their study site is Montana. Malcolm gave a presentation
earlier this year in Edinburgh which presented updated analyses on his BP work which played
down the CO2 influence.
regards
Rob
----- Original Message -----
From: [1]Martin Juckes
To: [2]Rob Wilson
Cc: [3]Keith Briffa ; [4]Myles Allen ; [5]Jan Esper ; [6]anders@misu.su.se ;
[7]Eduardo.Zorita@gkss.de ; [8]hegerl@duke.edu ; [9]weber@knmi.nl ; [10]t.osborn@uea.ac.uk
Sent: Thursday, November 16, 2006 4:41 PM
Subject: Re: Mitrie: Bristlecones
Thanks for all those comments.
I'm trying to avoid omitting data on the basis of cicrumstantial evidence,
even when it is presented enthusiastically. The Bunn et al. study is
interesting (attached) because they show estimated dates of the onset of
strip-bark growth. It looks to me as though the growth anomaly of the
strip-bark trees relative to the others is more to do with this change than
anything else. The onset of a positive growth anomaly in the 1850s is
certainly too early to be associated with CO2 increases.
cheers,
Martin
On Thursday 16 November 2006 14:51, Rob Wilson wrote:
> Re: Mitrie: BristleconesDear All,
> For the D'Arrigo et al. 2006 paper, I did indeed consider using the
Bristlecone pine data.
> However, due to the issues raised by Macintyre and others, we felt that it
would be unwise to use these data, especially as our data-set was biased more
to higher latitudes.
>
> However, I did look at the data. I do not like ignoring potential data-sets.
>
> Of the BP data that I managed to get my hands on, I identified a
significant, but relatively weak, correlation with local gridded mean summer
temperatures for three sites. These three sites are: Hermit Hill (N = 38;
1048-1983) and Windy Ridge (N = 29; 1050-1985) from Colorado and Sheep
Mountain (N = 71; 0 - 1990) from California.
>
> The attached figure compares the RCS chronology using these data (very
similar to the STD version in actual fact) with the North American RCS
composite series used in D'Arrigo et al. (2006). Both series have been
normalised to the 1200-1750 period to highlight any potential differences in
the 20th century.
>
> There is generally fairly good coherence between the two series between 1100
and the 1900. I personally do not think we have enough sites prior to 1400,
so the lack of coherence prior to 1100 might just reflect regional
differences and not enough series to derive a meaningful mean function.
Although correlation with gridded temperatures are relatively low (~0.40),
the coherence with the NA composite would seem to suggest that temperature is
the dominant signal over the last 900 years or so.
>
> In the 20th century, the BP index values are clearly UNDER the NA mean. I
would interpret this as suggesting that there does not appear to be any CO2
influence in the BP data. This of course assumes that there is no
fertilisation effect in the rest of the NA data.
>
> There is also the Salzer BP based temperature reconstruction:
> [11]
>
> again this does not correlate particular well with gridded temperatures - in
fact it is driven more by trends, but there are some similarities with my BP
chronology and NA series.
>
> I hope this helps the discussion
> best regards
> Rob
>
>   ----- Original Message -----
>   From: Jan Esper
>   To: Keith Briffa ; Martin Juckes ; Myles Allen
>   Cc: [12]anders@misu.su.se ; [13]Eduardo.Zorita@gkss.de ; [14]hegerl@duke.edu ;
[15]weber@knmi.nl ; [16]t.osborn@uea.ac.uk ; Wilson Rob
>   Sent: Thursday, November 16, 2006 1:36 PM
>   Subject: Re: Mitrie: Bristlecones
>
>
>   ...no, no, not a lot to add from my side. This is much more than I could
have said. Except, I once looked at strip bark growth trees in Central Asia,
and at least there the cause for this growth form was clear to me (Esper
2000, The Holocene):
>
>
>   "Strip-bark growth forms (Ferguson, 1968; Fritts, 1969; Graybill and Idso,
1993; Kelly et al., 1992; Wright and Mooney, 1965) also appear in older
Juniper trees. This condition develops as the cambium is damaged locally and
will no longer be overgrown. Mechanical damage by rockfall seems to be the
principle stimulus for cambial dieback and unilateral growth. In extreme
cases only a narrow strip on the stem is still active, creating these
eccentric growth forms."
>
>
>   I didn't visit the Bristlecone sites yet, but the mechanism might be the
same (some physical damage).
>
>
>   I believe that over time the crown and root system are reduced, but not at
the same rate than the reduction in circumference covered by the cambium.
This would be the key for strip bark tree rings being wider than "normal"
rings.
>
>
>   I am not very convinced that there are long-term fertilization effects by
CO2 (but have of course no proof for this). As far as I know, (most) results
from free air CO2 enrichment experiments suggest that there is no long-term
effect.
>
>
>   I Cc Rob Wilson to the mail, as he might have looked at Bristlecone data
recently. Pehaps he wants to add something.
>
>
>   Best --je
>
>
>   At 11:57 Uhr +0000 16.11.2006, Keith Briffa wrote:
>     Martin and all,
>     I know Franco very well - but he has not worked extensively with the
Bristlecones. I still believe that it  would be wise to involve Malcolm
Hughes in this discussion - though I recognise the point of view that says we
might like to appear (and be) independent of the original Mann, Bradley and
Hughes team to avoid the appearance of collusion. In my opinion (as someone
how has worked with the Bristlecone data hardly at all!) there are
undoubtedly problems in their use that go beyond the strip bark problem (that
I will come back to later).
>     The main one is an ambiguity in the nature and consistency of their
sensitivity to temperature variations. It was widely believed some 2-3
decades ago, that high-elevation trees were PREDOMINANTLY responding to
temperature and low elevation ones  to available water supply (not always
related in a simple way to measured precipitation) . However, response
functions ( ie sets of regression coefficients on monthly mean temperature
and precipitation data derived using principal components regression applied
to the tree-ring data) have always shown quite weak and temporally unstable
associations between chronology and climate variations (for the
high-elevations trees at least). The trouble is that these results are
dominated by inter-annual (ie high-frequency) variations and apparent
instability in the relationships is exacerbated by the shortness of the
instrumental records that restrict analyses to short periods, and the large
separation of the climate station records from the sites of the trees.
Limited comparisons between tree-ring density data (which seem to display
less ambiguos responses) imply that there is a reasonable decadal time scale
association and so indicate a real temperature signal , on this time
scale .The bottom line though is that these trees likely represent a mixed
temperature and moisture-supply response that might vary on longer
timescales.
>     The discussion is further complicated by the fact that the first PC of
"Western US" trees used in the Mann et al. analyses is derived from a mixture
of species (not just Bristlecones ) and they are quite varied in their
characteristics , time span, and effective variance spectra . Many show low
interannual variance and a long-term declining trend , up until about 1850 ,
when the Bristlecones (and others) show the remarkable increasing trend up
until the end of the record. The earlier negative trend could be (partly or
more significantly) a consequence of the LACK of detrending to allow for age
effects in the measurements (ie standardisation) - the very early sections of
relative high growth were removed in their analysis, but no explicit
standardistion of the data was made to account for remaining slow width
changes resulting from tree aging.  This is also related to the "strip bark"
problem , as these types of trees will have unpredictable trends as a
consequence of aging  and depending on the precise nature of each tree's
structure .
>      Another serious issue to be considered relates to the fact that the PC1
time series in the Mann et al. analysis was  adjusted to reduce the positive
slope in the last 150 years (on the assumption - following an earlier paper
by Lamarche et al. - that this incressing growth was evidence of carbon
dioxide fertilization) , by differencing the data from another record
produced by other workers in  northern Alaska and Canada (which  incidentally
was standardised in a totally different way). This last adjustment obviously
will have a large influence on the quantification of the link between these
Western US trees and N.Hemisphere temperatures. At this point , it is fair to
say that this adjustment was arbitrary and the link between Bristlecone pine
growth and CO2 is , at the very least, arguable. Note that at least one
author (Lisa Gaumlich) has stated that the recent growth of these trees could
be temperature driven and not evidence of CO2 fertilisation.
>
>     The point of this message is to show that that this issue is complex ,
and I still believe the "Western US" series and its interpretation in terms
of Hemispheric mean temperature is perhaps a "Pandora's box" that we might
open at our peril!
>     What does Jan say about this - he is very acquainted with these issues?
>
>     cheers
>     Keith
>     At 15:01 15/11/2006, Martin Juckes wrote:
>       Hi,
>
>       Concerning Bristlecones, I had a sympathetic reply from Prof. North,
but he
>       deferred to the person who wrote the relevant paragraph in the NAS
report
>       (Franco Biondi) who is firmly of the view that strip-bark bristlecones
should
>       not be used. I've read a few of the articles cited to back up this
statement
>       and I am surprised by the extreme weakness of the evidence. There is
one
>       study of 27 strip-bark pines which shows that they clearly developed
>       anomalous growth around 1850. Attributing this to CO2 is odd, to say
the
>       least. I'm writing a brief review of the literature which I'll send
round in
>       a few days time.
>
>       cheers,
>       Martin
>
>       On Sunday 12 November 2006 22:21, Myles Allen wrote:
>       > Although it probably doesn't feel like it, it seems to me you're
doing
>       > rather well...
>       >
>       > -----Original Message-----
>       > From: Martin Juckes
>       > Sent: 10 November 2006 15:24
>       > To: [17]anders@misu.su.se; [18]Eduardo.Zorita@gkss.de; [19]hegerl@duke.edu;
>       > [20]esper@wsl.ch; [21]k.briffa@uea.ac.uk; Myles Allen; [22]weber@knmi.nl;
>       > [23]t.osborn@uea.ac.uk
>       > Subject: Mitrie
>       >
>       > Hello,
>       >
>       > well, I've had a few exchanges on climateaudit, and decided to leave
>       > them to
>       > it for a few days.
>       >
>       > I'm going to send an email to Prof. North of the NAS panel to ask if
he
>       > really
>       > meant "don't use bristlecones", as he is quoted by McIntyre. I
believe
>       > it
>       > would be incorrect to select sites on the basis of what the data
from
>       > the
>       > sites looks like, and this makes up a substantial part of the
argument
>       > in
>       > Graybill and Idso (1993).
>       >
>       > Does anyone know where I can get hold of the categorisation of the
Sheep
>       >
>       > Mountain trees used by Graybill and Idso (ca534.rwl from the WDC for
>       > paleoclimatology I think) into "strip-bark" and "full-bark"? I've
sent
>       > an
>       > email to the WDC query address.
>       >
>       > I've also sent of for a publication which is cited by co2science as
>       > using
>       > Sargasso Sea data with the dating shifted by 50 years (Loehle,
2004,
>       > Ecological Modelling). This appears to be a source of considerable
>       > confusion
>       > among the climate sceptics. The shifted series fits nicely with the
idea
>       > that
>       > the Medieval Warm Period was warmer than the 20th century, so there
is a
>       >
>       > widespread perception that it is being ignored to fudge the results.
>       >
>       > Apart from a couple of oversights in the documentation of the data
files
>       >
>       > McIntyre hasn't come up with much yet. I need to read up a bit more
on
>       > the
>       > different Tornetraesk/Fennoscandia series.  There was an interesting
>       > discussion on "cherrypicking", with contributors suggesting that
testing
>       > the
>       > effect of removing each proxy series in turn was "cherrypicking" and
>       > that
>       > selecting series based on subjective analysis of what the series
look
>       > like
>       > would be much better!
>       >
>       > I've had a comment from the editor saying that responses to
non-refereee
>       >
>       > comments are optional, especially if the comments are not relevant
to
>       > the
>       > paper.
>       >
>       > cheers,
>       > Martin
>       >
>       >
>       >
>
>     --
>     Professor Keith Briffa,
>     Climatic Research Unit
>     University of East Anglia
>     Norwich, NR4 7TJ, U.K.
>
>     Phone: +44-1603-593909
>     Fax: +44-1603-507784
>
>     [24]
>
>
>
>
> --
> PD Dr. Jan Esper
>   Swiss Federal Research Institute WSL
>   Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
>   Voice: +41-44-739 2510
>   Fax:   +41-44-739 2515
>   [25]
References
1. mailto:m.n.juckes@rl.ac.uk
2. mailto:rob.wilson@ed.ac.uk
3. mailto:k.briffa@uea.ac.uk
4. mailto:allen@atm.ox.ac.uk
5. mailto:esper@wsl.ch
6. mailto:anders@misu.su.se
7. mailto:Eduardo.Zorita@gkss.de
8. mailto:hegerl@duke.edu
9. mailto:weber@knmi.nl
10. mailto:t.osborn@uea.ac.uk
11.
12. mailto:anders@misu.su.se
13. mailto:Eduardo.Zorita@gkss.de
14. mailto:hegerl@duke.edu
15. mailto:weber@knmi.nl
16. mailto:t.osborn@uea.ac.uk
17. mailto:anders@misu.su.se
18. mailto:Eduardo.Zorita@gkss.de
19. mailto:hegerl@duke.edu
20. mailto:esper@wsl.ch
21. mailto:k.briffa@uea.ac.uk
22. mailto:weber@knmi.nl
23. mailto:t.osborn@uea.ac.uk
24.
25.


Martin Juckes wrote:
> Hello Prof. Hughes,
>
> I'm involved in a discussion with Stephen McIntyre about Bristlecone pines,
> which I have used as temperature proxies in a recent work
> (
>
> I've read the NAS report section on this issue, and most of the references
> cited in the paragraph about bristlecones. I'm unimpressed by the evidence
> presented to support the idea that these valuable records of past climate
> should be discarded. In particular, the most relevant study appears to be
> that of Bunn et al., and this clearly shows anomalous strip-bark growth
> occurring well before significant atmospheric CO2 rises. Their study used
> whitebark pine, which is clearly not the same as bristlecone, but perhaps
> closer than the orange trees cited by Graybill and Idso.
>
> I'm looking for further literature and if possible data on the issue. Do you
> know of any data on anomalous growth in bristlecone strip-bark pines which is
> available for analysis?
>
> sincerely,
> Martin Juckes
>
Dear Dr. Jukes,
I'm afraid that, apart from the Bunn et al 2003 paper you mention, I
know of no other recent literature or data directly relevant to this
question. There is a graduate student here working on a dissertation
related to this, but neither their data nor any publications on them are
available at the moment. Two points concerning Graybill and Idso (1993):
1) I don't think the sour orange trees used in Sherwood Idso's
experiments were stripbark - where did this idea come from? 2) When
considering the use of upper forest border bristlecone pine (e.g. Sheep
Mountain, Campito Mountain, and similar sites mainly above 3100m in the
relevant region) as temperature proxies it would be a mistake to
discount Figure 3 in Graybill and Idso (1993) which is a comparison of a
ufb bristlecone pine chronology with a smoothed gridpoint reconstruction
from maximum latewood density in quite different trees provided by Keith
Briffa, one of your co-authors. I read this graph as confirmation of
LaMarche's interpretation of the ufb bcp records as having a ~bidecadal
temperature signal combined with an interannual precipitation signal, at
least before the 20th century. This is referred to Hughes and Funkhouser
(2003).
I hope this helps, Malcolm Hughes


Malcolm
sorry , I should have cc'd this message sent to my coauthors some time ago(it pre-dates the
message to you) , but I was sort of hoping this issue would recede . It would be useful to
chat about this and other stuff if you are able to phone (afternoon my time preferably).
Cheers
Keith
Date: Thu, 16 Nov 2006 11:57:09 +0000
To: Martin Juckes
, "Myles Allen"
From: Keith Briffa
Subject: Re: Mitrie: Bristlecones
Cc: anders@misu.su.se, Eduardo.Zorita@gkss.de, hegerl@duke.edu, esper@wsl.ch,
weber@knmi.nl, t.osborn@uea.ac.uk
Martin and all,
I know Franco very well - but he has not worked extensively with the Bristlecones. I
still believe that it  would be wise to involve Malcolm Hughes in this discussion -
though I recognise the point of view that says we might like to appear (and be)
independent of the original Mann, Bradley and Hughes team to avoid the appearance of
collusion. In my opinion (as someone how has worked with the Bristlecone data hardly at
all!) there are undoubtedly problems in their use that go beyond the strip bark problem
(that I will come back to later).
The main one is an ambiguity in the nature and consistency of their sensitivity to
temperature variations. It was widely believed some 2-3 decades ago, that high-elevation
trees were PREDOMINANTLY responding to temperature and low elevation ones  to available
water supply (not always related in a simple way to measured precipitation) . However,
response functions ( ie sets of regression coefficients on monthly mean temperature and
precipitation data derived using principal components regression applied to the
tree-ring data) have always shown quite weak and temporally unstable associations
between chronology and climate variations (for the high-elevations trees at least). The
trouble is that these results are dominated by inter-annual (ie high-frequency)
variations and apparent instability in the relationships is exacerbated by the shortness
of the instrumental records that restrict analyses to short periods, and the large
separation of the climate station records from the sites of the trees. Limited
comparisons between tree-ring density data (which seem to display less ambiguos
responses) imply that there is a reasonable decadal time scale association and so
indicate a real temperature signal , on this time scale .The bottom line though is that
these trees likely represent a mixed temperature and moisture-supply response that might
vary on longer timescales.
The discussion is further complicated by the fact that the first PC of "Western US"
trees used in the Mann et al. analyses is derived from a mixture of species (not just
Bristlecones ) and they are quite varied in their characteristics , time span, and
effective variance spectra . Many show low interannual variance and a long-term
declining trend , up until about 1850 , when the Bristlecones (and others) show the
remarkable increasing trend up until the end of the record. The earlier negative trend
could be (partly or more significantly) a consequence of the LACK of detrending to allow
for age effects in the measurements (ie standardisation) - the very early sections of
relative high growth were removed in their analysis, but no explicit standardistion of
the data was made to account for remaining slow width changes resulting from tree
aging.  This is also related to the "strip bark" problem , as these types of trees will
have unpredictable trends as a consequence of aging  and depending on the precise nature
of each tree's structure .
Another serious issue to be considered relates to the fact that the PC1 time series in
the Mann et al. analysis was  adjusted to reduce the positive slope in the last 150
years (on the assumption - following an earlier paper by Lamarche et al. - that this
incressing growth was evidence of carbon dioxide fertilization) , by differencing the
data from another record produced by other workers in  northern Alaska and Canada
(which  incidentally was standardised in a totally different way). This last adjustment
obviously will have a large influence on the quantification of the link between these
Western US trees and N.Hemisphere temperatures. At this point , it is fair to say that
this adjustment was arbitrary and the link between Bristlecone pine growth and CO2 is ,
at the very least, arguable. Note that at least one author (Lisa Gaumlich) has stated
that the recent growth of these trees could be temperature driven and not evidence of
CO2 fertilisation.
The point of this message is to show that that this issue is complex , and I still
believe the "Western US" series and its interpretation in terms of Hemispheric mean
temperature is perhaps a "Pandora's box" that we might open at our peril!
What does Jan say about this - he is very acquainted with these issues?
cheers
Keith
At 15:01 15/11/2006, Martin Juckes wrote:
Hi,
Concerning Bristlecones, I had a sympathetic reply from Prof. North, but he
deferred to the person who wrote the relevant paragraph in the NAS report
(Franco Biondi) who is firmly of the view that strip-bark bristlecones should
not be used. I've read a few of the articles cited to back up this statement
and I am surprised by the extreme weakness of the evidence. There is one
study of 27 strip-bark pines which shows that they clearly developed
anomalous growth around 1850. Attributing this to CO2 is odd, to say the
least. I'm writing a brief review of the literature which I'll send round in
a few days time.
cheers,
Martin
On Sunday 12 November 2006 22:21, Myles Allen wrote:
> Although it probably doesn't feel like it, it seems to me you're doing
> rather well...
>
> -----Original Message-----
> From: Martin Juckes [[1]mailto:m.n.juckes@rl.ac.uk]
> Sent: 10 November 2006 15:24
> To: anders@misu.su.se; Eduardo.Zorita@gkss.de; hegerl@duke.edu;
> esper@wsl.ch; k.briffa@uea.ac.uk; Myles Allen; weber@knmi.nl;
> t.osborn@uea.ac.uk
> Subject: Mitrie
>
> Hello,
>
> well, I've had a few exchanges on climateaudit, and decided to leave
> them to
> it for a few days.
>
> I'm going to send an email to Prof. North of the NAS panel to ask if he
> really
> meant "don't use bristlecones", as he is quoted by McIntyre. I believe
> it
> would be incorrect to select sites on the basis of what the data from
> the
> sites looks like, and this makes up a substantial part of the argument
> in
> Graybill and Idso (1993).
>
> Does anyone know where I can get hold of the categorisation of the Sheep
>
> Mountain trees used by Graybill and Idso (ca534.rwl from the WDC for
> paleoclimatology I think) into "strip-bark" and "full-bark"? I've sent
> an
> email to the WDC query address.
>
> I've also sent of for a publication which is cited by co2science as
> using
> Sargasso Sea data with the dating shifted by 50 years (Loehle,  2004,
> Ecological Modelling). This appears to be a source of considerable
> confusion
> among the climate sceptics. The shifted series fits nicely with the idea
> that
> the Medieval Warm Period was warmer than the 20th century, so there is a
>
> widespread perception that it is being ignored to fudge the results.
>
> Apart from a couple of oversights in the documentation of the data files
>
> McIntyre hasn't come up with much yet. I need to read up a bit more on
> the
> different Tornetraesk/Fennoscandia series.  There was an interesting
> discussion on "cherrypicking", with contributors suggesting that testing
> the
> effect of removing each proxy series in turn was "cherrypicking" and
> that
> selecting series based on subjective analysis of what the series look
> like
> would be much better!
>
> I've had a comment from the editor saying that responses to non-refereee
>
> comments are optional, especially if the comments are not relevant to
> the
> paper.
>
> cheers,
> Martin
>
>
>
--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593909
Fax: +44-1603-507784
[2]
--
Professor Keith Briffa,
Climatic Research Unit
University of East Anglia
Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593909
Fax: +44-1603-507784
[3]
References
1. mailto:m.n.juckes@rl.ac.uk
2.
3.


we still don't have an adequat explanation as to how Jack "cooked up" that figure - I do
not believe it was purely out of thin air - look at the attached - which I used in the
Crowley-Lowery composite just because it was "out there" - I made no claim that it was the
record of record, but just that it had been used beforer.  the Lamb ref. is his book dated
1966.  I will have to dig up the page ref later.  Dansgaard et al. 1975 Nature paper on
Norsemen...etc used that figure when comparing what must have been their Camp Century
record - have to check that too - where the main point of that paper was that the timing of
Medieval warmth was different in Greenlandn and England!
25 years later my provocation for writing the CL paper came from a strong statement on the
MWP by Claus Hammer that the canonical idea of the MWP being warming than the present was
correct and that the 1999 Mann et al was wrong.  he kept going on like that I reminded him
that he was a co-author on the 1975 paper!  that is also what motivated to do my "bonehead"
sampling of whatever was out there just to see what happened when you added them all
together - the amazing result was that it looked pretty much like Mann et al.  ther rest is
history -- much ignored and forgotten.
I might also pointn out that in a 1996 Consequences article I wrote - and that Fred Singer
loves to cite -- Jack (who was the editor of the journal) basically shoehorned me into
re-reproducing that figure even though I didn't like it - there was not an alternative.  in
the figure caption it has a similar one to Zielinski except that it states "compiled by
R.S. Bradley and J.A. Eddy based on J.T. Houghton....so that puts a further twist on this
because it point to Houghton not Bradley/Eddy as the source.  Jack must have written that
part of the figure caption because I don't think I knew those details.
but we still don't know where the details of the figure came from - the MWP is clearly more
schematic than the LIA (actually the detailsl about timing of the samll wiggles in the LIA
are pretty good) - maybe there was a meshing of the Greenland and the England records to do
the MWP part - note that the English part gets cooler.  they may also have thrown in the
old LaMarche record - which I also have.  maybe I can schlep something together using only
those old three records.
tom
Michael E. Mann wrote:
Ray, happy holidays and thanks for the (quite fascinating) background on this. It would be
good material for a Realclimate article. would be even better if someone could get Chris on
record confirming that this is indeed the history of this graphic...
mike
raymond s. bradley wrote:
I believe this graph originated in a (literally) grey piece of literature that Jack Eddy
used to publish called "Earth Quest".  It was designed for, and distributed to, high
school teachers.  In one issue, he had a fold-out that showed different timelines,
Cenozoic, Quaternary, last 100ka, Holocene, last millennium, last century etc.  The idea
was to give non-specialists a perspective on the earth's climate history.  I think this
idea evolved from the old NRC publication edited by L. Gates, then further elaborated on
by Tom Webb in the book I edited for UCAR, Global Changes of the Past.  (This was an
outcome of the wonderful Snowmass meeting Jack master-minded around 1990).
I may have inadvertently had a hand in this millennium graph!  I recall getting a fax
from Jack with a hand-drawn graph, that he asked me to review.  Where he got his version
from, I don't know.  I think I scribbled out part of the line and amended it in some
way, but have no recollection of exactly what I did to it.  And whether he edited it
further, I don't know.  But as it was purely schematic (& appears to go through ~1950)
perhaps it's not so bad.  I note, however, that in the more colourful version of the
much embellished graph that Stefan circulated ([1]

the end-point has been changed to 2000, which puts quite a different spin on things.
They also seem to have fabricated a scale for the purported temperature changes.  In any
case, the graph has no objective basis whatsoever; it is purely a "visual guess" at what
happened, like something we might sketch on a napkin at a party for some overly
persistent inquisitor..... (so make sure you don't leave such things on the table...).
What made the last millennium graph famous (notorious!) was that Chris Folland must have
seen it and reproduced it in the 1995 IPCC chapter he was editing.  I don't think he
gave a citation and it thus appeared to have the imprimatur of the IPCC. Having
submitted a great deal of text for that chapter, I remember being really pissed off that
Chris essentially ignored all the input, and wrote his own version of the paleoclimate
record in that volume.
There are other examples of how Jack Eddy's grey literature publication was misused.  In
a paper in Science by Zielinski et al. (1994) [v.264, p.448-452]--attached-- they
reproduced [in Figure 1c] a similarly schematic version of Holocene temperatures giving
the following citation, "Taken from J. A. Eddy and R. S. Bradley, Earth-quest 5 (insert)
(1991), as modified from J. T. Houghton, G. J. Jenkins, J. J. Ephraums, Climate Change,
The IPCC Scientific Assessment (Cambridge Univ. Press, Cambridge, 1990)."
But I had nothing to do with that one!
So, that's how a crude fax from Jack Eddy became the definitive IPCC record on the last
millennium!
Happy New Year to everyone
Ray
Raymond S. Bradley
Director, Climate System Research Center*
Department of Geosciences, University of Massachusetts
Morrill Science Center
611 North Pleasant Street
AMHERST, MA 01003-9297
Tel: 413-545-2120
Fax: 413-545-1200
*Climate System Research Center: 413-545-0659
Paleoclimatology Book Web Site: [3]
Publications (download .pdf files):
[4]
--
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:  [5]mann@psu.edu
University Park, PA 16802-5013
[6]
Attachment Converted: "c:\eudora\attach\Lamb_ext.pdf"
References
1.
2.
3.
4.
5. mailto:mann@psu.edu
6.


for those who are interested, there is a paper by Goosse et al (I'm a co-author) explaining
why parts of Europe such as central england would have experienced warmer summer conditions
relative to present than other regions, related to early land-use change:
Goosse, H., Arzel, O., Luterbacher, J., Mann, M.E., Renssen, H., Riedwyl, N., Timmermann,
A., Xoplaki, E., Wanner, H., [1]The origin of the European "Medieval Warm Period", Climate
of the Past, 2, 99-113, 2006.
paper available as pdf here:
[2]~mann/shared/articles/Goosseetal-CP06.pdf
meanwhile, winter warmth could have been due to a strong AO/NAO pattern associated with
decreased volcanism and high solar, as discussed in the various Shindell et al paper.
this simply underscores the point that we all often make, that one needs to take into
account regional factors when interpreting regional records. This is especially relevant to
the extrapolation of a long record from England to the entire NH (which appears to have
been tacitly done by Jack Eddy?),
mike
Tom Crowley wrote:
we still don't have an adequat explanation as to how Jack "cooked up" that figure - I do
not believe it was purely out of thin air - look at the attached - which I used in the
Crowley-Lowery composite just because it was "out there" - I made no claim that it was the
record of record, but just that it had been used beforer.  the Lamb ref. is his book dated
1966.  I will have to dig up the page ref later.  Dansgaard et al. 1975 Nature paper on
Norsemen...etc used that figure when comparing what must have been their Camp Century
record - have to check that too - where the main point of that paper was that the timing of
Medieval warmth was different in Greenlandn and England!
25 years later my provocation for writing the CL paper came from a strong statement on the
MWP by Claus Hammer that the canonical idea of the MWP being warming than the present was
correct and that the 1999 Mann et al was wrong.  he kept going on like that I reminded him
that he was a co-author on the 1975 paper!  that is also what motivated to do my "bonehead"
sampling of whatever was out there just to see what happened when you added them all
together - the amazing result was that it looked pretty much like Mann et al.  ther rest is
history -- much ignored and forgotten.
I might also pointn out that in a 1996 Consequences article I wrote - and that Fred Singer
loves to cite -- Jack (who was the editor of the journal) basically shoehorned me into
re-reproducing that figure even though I didn't like it - there was not an alternative.  in
the figure caption it has a similar one to Zielinski except that it states "compiled by
R.S. Bradley and J.A. Eddy based on J.T. Houghton....so that puts a further twist on this
because it point to Houghton not Bradley/Eddy as the source.  Jack must have written that
part of the figure caption because I don't think I knew those details.
but we still don't know where the details of the figure came from - the MWP is clearly more
schematic than the LIA (actually the detailsl about timing of the samll wiggles in the LIA
are pretty good) - maybe there was a meshing of the Greenland and the England records to do
the MWP part - note that the English part gets cooler.  they may also have thrown in the
old LaMarche record - which I also have.  maybe I can schlep something together using only
those old three records.
tom
Michael E. Mann wrote:
Ray, happy holidays and thanks for the (quite fascinating) background on this. It would be
good material for a Realclimate article. would be even better if someone could get Chris on
record confirming that this is indeed the history of this graphic...
mike
raymond s. bradley wrote:
I believe this graph originated in a (literally) grey piece of literature that Jack Eddy
used to publish called "Earth Quest".  It was designed for, and distributed to, high
school teachers.  In one issue, he had a fold-out that showed different timelines,
Cenozoic, Quaternary, last 100ka, Holocene, last millennium, last century etc.  The idea
was to give non-specialists a perspective on the earth's climate history.  I think this
idea evolved from the old NRC publication edited by L. Gates, then further elaborated on
by Tom Webb in the book I edited for UCAR, Global Changes of the Past.  (This was an
outcome of the wonderful Snowmass meeting Jack master-minded around 1990).
I may have inadvertently had a hand in this millennium graph!  I recall getting a fax
from Jack with a hand-drawn graph, that he asked me to review.  Where he got his version
from, I don't know.  I think I scribbled out part of the line and amended it in some
way, but have no recollection of exactly what I did to it.  And whether he edited it
further, I don't know.  But as it was purely schematic (& appears to go through ~1950)
perhaps it's not so bad.  I note, however, that in the more colourful version of the
much embellished graph that Stefan circulated ([3]

the end-point has been changed to 2000, which puts quite a different spin on things.
They also seem to have fabricated a scale for the purported temperature changes.  In any
case, the graph has no objective basis whatsoever; it is purely a "visual guess" at what
happened, like something we might sketch on a napkin at a party for some overly
persistent inquisitor..... (so make sure you don't leave such things on the table...).
What made the last millennium graph famous (notorious!) was that Chris Folland must have
seen it and reproduced it in the 1995 IPCC chapter he was editing.  I don't think he
gave a citation and it thus appeared to have the imprimatur of the IPCC. Having
submitted a great deal of text for that chapter, I remember being really pissed off that
Chris essentially ignored all the input, and wrote his own version of the paleoclimate
record in that volume.
There are other examples of how Jack Eddy's grey literature publication was misused.  In
a paper in Science by Zielinski et al. (1994) [v.264, p.448-452]--attached-- they
reproduced [in Figure 1c] a similarly schematic version of Holocene temperatures giving
the following citation, "Taken from J. A. Eddy and R. S. Bradley, Earth-quest 5 (insert)
(1991), as modified from J. T. Houghton, G. J. Jenkins, J. J. Ephraums, Climate Change,
The IPCC Scientific Assessment (Cambridge Univ. Press, Cambridge, 1990)."
But I had nothing to do with that one!
So, that's how a crude fax from Jack Eddy became the definitive IPCC record on the last
millennium!
Happy New Year to everyone
Ray
Raymond S. Bradley
Director, Climate System Research Center*
Department of Geosciences, University of Massachusetts
Morrill Science Center
611 North Pleasant Street
AMHERST, MA 01003-9297
Tel: 413-545-2120
Fax: 413-545-1200
*Climate System Research Center: 413-545-0659
Paleoclimatology Book Web Site: [5]
Publications (download .pdf files):
[6]
--
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:  [7]mann@psu.edu
University Park, PA 16802-5013
[8]
--
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:  [9]mann@psu.edu
University Park, PA 16802-5013
[10]
References
1. file://localhost/tmp/Goosseetal-CP06.pdf
2. ~mann/shared/articles/Goosseetal-CP06.pdf
3.
4.
5.
6.
7. mailto:mann@psu.edu
8.
9. mailto:mann@psu.edu
10.


sounds good Phil, I agree on the forecast. I think its at least
'plausible' ;)
by the way, please remind me what input you need from me at this point
on the Wengen paper. I've attached a review paper I've got in press in
"AREPS". Not sure if I sent this to you before. Its mostly a re-tread of
our '04 Rev Geophys review (which is getting lots of citations if you've
noticed!), but a little bit of newer stuff.
talk to you later,
mike
Phil Jones wrote:
>
>  Mike,
>     I'm just beginning to notice this. I talked to AP about 5 hours ago.
>  Our google search has noticed 150 in the last 3 hours.
>  I checked one - can't recall whether it was Minneapolis of San Diego,
>  but it read OK.
>
>     It's a trivial forecast. GW plus ENSO.
>
>  Cheers
>  Phil
>
>
>      I was hoping to put some of this background to the IPCC figure
>  into the Wengen paper, but the more places the merrier.
>
>      By the way - when I'll send out a reminder.
>
>  Phil
>
>
> At 16:19 04/01/2007, Michael E. Mann wrote:
>
>> by the way, 2007 to be warmest year headline getting a huge amount of
>> play in the U.S. media today,
>>
>> mike
>>
>> Phil Jones wrote:
>>
>>>
>>>  Dear All,
>>>     The net is closing...
>>>
>>> National Research Council, US Committee for the Global Atmospheric
>>> Research Program, Understanding Climatic Change: A Program for Action,
>>> National Academy of Sciences, Washington, DC, (1975), appendix A.
>>>
>>>  This book (Fig A2b) has the same figure as Imbrie/Imbrie. It is
>>> rotated.
>>>  It also has the same concept of the IPCC 1990 Figure, changes on
>>>  various timescales - all rotated. Loads of Lamb diagrams I have
>>>  seen countless times before.
>>>
>>>  This book also talks about the impending cooling.....
>>>
>>>  John Mitchell also thought the figure is in a book by Gribbin
>>>  called '1982 CO2 Review". Anyone recall that one. This isn't
>>>  in the CRU Library nor UEA's.
>>>
>>>  The direct source of the IPCC diagram is the UK Dept of Environment
>>>  document from 1989 which is being posted to me. It though has
>>>  a source, which isn't in the document. John and Geoff Jenkins
>>>  wrote it though.  It is possible that just the last millennium panel
>>>  was from this source and the others from this 1975 source.
>>>
>>>  Cheers
>>>  Phil
>>>
>>>
>>>
>>>
>>>
>>>  Dear All (Tom is off to Texas),
>>>      David Warrilow has found the said report. A photocopy is being
>>> posted
>>>  to me, and two others have been asked if they know more about how
>>>  it was arrived at.
>>>
>>>     I'll report more when I get news.
>>>
>>>  Phil
>>>
>>> Tom,
>>>    Here's a reply from David Warrilow (below). I still think it is
>>>  in a UK Dept of the Environment report from 1988/89, as does
>>>  Chris Folland, so have asked him to think a little more.
>>>    I've looked at the 1979 edition, and Figure 45 is the one.
>>>  It has a curve, but with the 20th century warmer than the
>>>  MWP!! It is said to be based on Lamb (1969). This is a
>>>  chapter in the World Survey of Climatology Series
>>>  edited by Landsberg. I can't see how you can adapt anything
>>>  from this. Hubert's chapter has lots of detail, many figures
>>>  which have lines with the phrase 'analyst's opinion' - one
>>>  of his favourite terms for things he made up. If it is an
>>>  adaptation, then it comes from Hubert's ideas about
>>>  England and NW Europe, because these are the curves
>>>  in the 1969 chapter.
>>>
>>>     Anyone have the 1986 edition, to see if this curve got changed?
>>>  The 1986 date is about right for being in the document I recall
>>>  seeing. Some of you who've seen my room, will be saying if I had
>>>  a better filing system, then I would be able to find it. Despite
>>> keeping
>>>  most things I can't find this !
>>>
>>>      By the way, it is GREAT PITY, the First IPCC report didn't use
>>>  Fig 45. We'd all be very happy and the skeptics wouldn't be going
>>>  on about what came out in 1990.
>>>
>>>      Attached is the Met Office forecast for 2007. It seems that I'm
>>> getting
>>>  the credit for this in the media. All I did was talk to the
>>> Independent about
>>>  what I thought 2007 had in store weatherwise. With an El Nino going
>>> on,
>>>  I thought it might be a record and just trotted off the typical
>>> things that happen
>>>  in El Nino years.
>>>
>>>  Cheers
>>>  Phil
>>>
>>>
>>>  Phil,
>>>
>>> I can't be sure but I think the original diagram is from Imbrie and
>>> Imbrie :
>>> Imbrie, John and Katherine Palmer Imbrie. Ice ages: Solving the
>>> Mystery. Cambridge, Massachusetts: Harvard University Press, 1979,
>>> 1986 (reprint). ISBN 0-89490-020-X; ISBN 0-89490-015-3; ISBN
>>> 0-674-44075-7. p. 25
>>>
>>> You may have it in your library. I am afraid I don't have it to hand,
>>>
>>> David
>>>
>>>
>>>
>>> Prof. Phil Jones
>>> Climatic Research Unit        Telephone +44 (0) 1603 592090
>>> School of Environmental Sciences    Fax +44 (0) 1603 507784
>>> University of East Anglia
>>> Norwich                          Email    p.jones@uea.ac.uk
>>> NR4 7TJ
>>> UK
>>> ----------------------------------------------------------------------------
>>>
>>
>>
>>
>>
>> --
>> 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
>>
>>
>>
>
> Prof. Phil Jones
> Climatic Research Unit        Telephone +44 (0) 1603 592090
> School of Environmental Sciences    Fax +44 (0) 1603 507784
> University of East Anglia
> Norwich                          Email    p.jones@uea.ac.uk
> NR4 7TJ
> UK
> ----------------------------------------------------------------------------
>
--
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

Attachment Converted: "c:\eudora\attach\AREPS-preprint061.pdf"


On Thu, 4 Jan 2007, Caspar Ammann wrote:
> check figure A9, there the 17th century is cold, and this is probably
> the curve that was used. In that case, then its Central England from Lamb.
Ah, you mean A9(d) (I thought you meant A9(a) for a bit). Yes, that looks pretty
similar to IPCC 1990. Though not identical - the scaling is different, but the
timing is similar.
-W.
> Caspar
>
>
> William M Connolley wrote:
> > On Thu, 4 Jan 2007, Phil Jones wrote:
> >
> >>      The net is closing...
> >>
> >> National Research Council, US Committee for the Global Atmospheric
> >> Research Program, Understanding Climatic Change: A Program for Action,
> >> National Academy of Sciences, Washington, DC, (1975), appendix A.
> >>
> >>   This book (Fig A2b) has the same figure as Imbrie/Imbrie. It is rotated.
> >>   It also has the same concept of the IPCC 1990 Figure, changes on
> >>   various timescales - all rotated. Loads of Lamb diagrams I have
> >>   seen countless times before.
> >>
> >
> > ? The source for IPCC can't be the 1975 NAS report. That fig is relatively warm
> > about 1600; the IPCC '90 figure is cold then. And as noted the "MWP" is colder
> > than 1950. But NAS 75 is the same as I+I, true (they both source to Lamb 69).
> >
> > Incidentally my I+I says copyright 1979, seventh printing 1998.
> >
> > -W.
> >
> > William M Connolley | wmc@bas.ac.uk |
> > Climate Modeller, British Antarctic Survey | (01223) 221479
> >
> > --
> > This message (and any attachments) is for the recipient only.  NERC is subject
> > to the Freedom of Information Act 2000 and the contents of this email and any
> > reply you make may be disclosed by NERC unless it is exempt from release under
> > the Act.  Any material supplied to NERC may be stored in an electronic
> > records management system.
> >
> >
> >
>
> --
> 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
>
William M Connolley | wmc@bas.ac.uk |
Climate Modeller, British Antarctic Survey | (01223) 221479
--
This message (and any attachments) is for the recipient only.  NERC is subject
to the Freedom of Information Act 2000 and the contents of this email and any
reply you make may be disclosed by NERC unless it is exempt from release under
the Act.  Any material supplied to NERC may be stored in an electronic
records management system.


Greetings,
I have now heard back from all of you and the only date that will work for all of you will
be Monday, 8 January (that's Tuesday, 9 January for Nathan & Zhenlin). A small adjustment
to the time would be necessary to accommodate all of you. To ensure that we would have
enough time for everyone to participate in the entire call we would need to start 30
minutes earlier. So, that would be 12:30 MST/I9:30 UTC. I am going to hope that is ok and
move forward with establishing the call. Please let me know ASAP if that time adjustment
will NOT work for you. You will receive another email from me shortly with the details.
Please also let me know if the following contact information changes for you.
Susan Solomon          +1 303 497 3483
Martin Manning        +1 303 497 4479
Nathan Bindoff          +61 3 62262986
Kevin Trenberth         +1 303 497 1318
Matilde Rusticucci    +54 11 4797 4672
Phil Jones                  +44 1953 605643
Brian Hoskins            +44 118 98411308
Peter Lemke              +49 5193 1458
Jurgen Willebrand      +49 431 688475
Zhenlin Chen             + 86 10 68406146
Cheers,
Melinda
Melinda Tignor wrote:
Greetings,
I am contacting you to schedule the upcoming teleconference. Due to the extreme variability
in your time zones this will likely be a bit tricky and outside "normal" business hours for
some of you.
Please let me know as soon as possible your availability for the following times for the
week of 8 Jan - 12 Jan:
Nathan - 7:00 (Hobart)
Kevin - 13:00 (MST)
Matilde - 17:00 (Buenos Aires)
Phil, Brian - 20:00 (UK)
Peter, Jurgen - 21:00 (Germany)
Again, I realize that some of you would be most likely taking this call from home due to
the early or late time.
Many thanks in advance for your prompt response.
Cheers,
Melinda
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Melinda M.B. Tignor
Program Administrator
Intergovernmental Panel on Climate Change
Working Group I Technical Support Unit
NOAA Chemical Sciences Division
325 Broadway DSRC CSD08
Boulder, CO 80305 USA
Phone: +1 303 497 7072
Fax: +1 303 497 5686/5628
Email: [1]tignor@ucar.edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Melinda M.B. Tignor
Program Administrator
Intergovernmental Panel on Climate Change
Working Group I Technical Support Unit
NOAA Chemical Sciences Division
325 Broadway DSRC CSD08
Boulder, CO 80305 USA
Phone: +1 303 497 7072
Fax: +1 303 497 5686/5628
Email: [2]tignor@ucar.edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
References
1. mailto:tignor@ucar.edu
2. mailto:tignor@ucar.edu


Dear All,
I've added a few extra names in the cc of this email list to see if we can
definitively determine where the figure in the subject title comes from. The
background is that the skeptics keep referring back to it and I'd like
to prove that it is a schematic and it isn't based on real data, but on
presumed knowledge at some point around the late 1980s. If you think
it is based on something real.
What we'd like to do is show this either on 'Real Climate' or as background
in a future paper, or both.
I'm attaching a few diagrams as background (attaching in order of
introducing them) and giving some earlier thoughts. I assume you all have
a copy of the said diagram in the first IPCC report.
1.  This is where the IPCC diagram came from - the top panel is also
there, but the middle one from IPCC isn't. This is where Chris Folland
knows it came from. He said it was shoehorned in at a very late date.
This report comes from a UK Dept of the Environment document - where the
first edition predates 1990. David Warrilow says that this was written by
Geoff Jenkins and John Mitchell.
John said the following
I think it was based on a diagram A2 in the national Academy of Sciences
boolet "Understanding climate change" cirica 1974 if rmeber correctly- I
can find out in Reading tomorrow- which I can't find in the library- it
was reproduced in one of John Gribbens books and I think a book claled
the "1982 CO2 review". I think there 6 diagrams and I remember Tom
Wigley commenting that only the first ( millions of years) and Last (
instrumental record) had any credibility.
and
National Research Council, US Committee for the Global Atmospheric
Research Program, Understanding Climatic Change: A Program for Action,
National Academy of Sciences, Washington, DC, (1975), appendix A.
2. This 1975 book has the 3rd attachment on p130 . This is very similar to one
that David Warrilow said (also attached from Imbrie and Imbrie - second
attachment).
from David
I can't be sure but I think the original diagram is from Imbrie and Imbrie :
Imbrie, John and Katherine Palmer Imbrie. Ice ages: Solving the Mystery. Cambridge,
Massachusetts: Harvard University Press, 1979, 1986 (reprint). ISBN 0-89490-020-X; ISBN
0-89490-015-3; ISBN 0-674-44075-7. p. 25
These look the same if you invert and rotate the one from 1975, and they both
say 'winter conditions in Eastern Europe' - well Imbrie/Imbrie do. They
also say adapted from Lamb (1969). This is the World Survey of Climatology
series from Landsberg, vol2. I've been through this and I can't see much
of a plot anything like those I've attached, so some adaptation. Also I've
no idea what this Eastern European series is!
The IPCC diagram and the UK report clearly don't originate here.
3. Caspar Amman had John Gribbin's 1982 book and sent the 4th
attachment. This has a warmer MWP, but is far too cool recently.
So even if this was resmoothed, it wouldn't before the IPCC one.
4. Ray Bradley sent this text:
I believe this graph originated in a (literally) grey piece of literature that Jack Eddy
used to publish called "Earth Quest".  It was designed for, and distributed to, high school
teachers.  In one issue, he had a fold-out that showed different timelines, Cenozoic,
Quaternary, last 100ka, Holocene, last millennium, last century etc.  The idea was to give
non-specialists a perspective on the earth's climate history.  I think this idea evolved
from the old NRC publication edited by L. Gates, then further elaborated on by Tom Webb in
the book I edited for UCAR, Global Changes of the Past.  (This was an outcome of the
wonderful Snowmass meeting Jack master-minded around 1990).
I may have inadvertently had a hand in this millennium graph!  I recall getting a fax from
Jack with a hand-drawn graph, that he asked me to review.  Where he got his version from, I
don't know.  I think I scribbled out part of the line and amended it in some way, but have
no recollection of exactly what I did to it.  And whether he edited it further, I don't
know.  But as it was purely schematic (& appears to go through ~1950) perhaps it's not so
bad.  I note, however, that in the more colourful version of the much embellished graph
that Stefan circulated (
[1]
the end-point has been changed to 2000, which puts quite a different spin on things.  They
also seem to have fabricated a scale for the purported temperature changes.  In any case,
the graph has no objective basis whatsoever; it is purely a "visual guess" at what
happened, like something we might sketch on a napkin at a party for some overly persistent
inquisitor..... (so make sure you don't leave such things on the table...).
What made the last millennium graph famous (notorious!) was that Chris Folland must have
seen it and reproduced it in the 1995 IPCC chapter he was editing.  I don't think he gave a
citation and it thus appeared to have the imprimatur of the IPCC. Having submitted a great
deal of text for that chapter, I remember being really pissed off that Chris essentially
ignored all the input, and wrote his own version of the paleoclimate record in that volume.
There are other examples of how Jack Eddy's grey literature publication was misused.  In a
paper in Science by Zielinski et al. (1994) [v.264, p.448-452]--attached-- they reproduced
[in Figure 1c] a similarly schematic version of Holocene temperatures giving the following
citation, "Taken from J. A. Eddy and R. S. Bradley, Earth-quest 5 (insert) (1991), as
modified from J. T. Houghton, G. J. Jenkins, J. J. Ephraums, Climate Change, The IPCC
Scientific Assessment (Cambridge Univ. Press, Cambridge, 1990)."
But I had nothing to do with that one!
So, that's how a crude fax from Jack Eddy became the definitive IPCC record on the last
millennium!
5. Finally, here's one from Stefan, to show how the IPCC diagram gets
(first another one which appears to be the IPCC 1990 diagram).
The one I want to attach seems to be within Stefan's email so that
is the end of this email. You can also get to this by going to the link
in Ray's piece above.
It shows how you can embellish a diagram and even get Rembrandt in!
I've also seen many other embellishments mentioning Greenland, the Vikings,
Vineyards in York, frost fairs on the Thames etc. Also I've emailed over
the years for the numbers in the 1990 IPCC Figure. I even got a digitized
version once from Richard Tol and told him what he'd done was
ludicrous.
6. So who put to together? Do we blame Ray? Is it a whim of his
excellent imagination?  I know we will all likely agree with Ray that
it is based on absolutely nothing. Tom Crowley thinks it might be
based on Lamb and sent the final figure. Now all of those who are
or were in CRU know, you should be very careful with Lamb diagrams!
This one does not stand any scrutiny and there are several more
recent papers by Tom Wigley, Astrid Ogilvie and Graham Farmer
that have shown that this final diagram is irreproducible and it was
much cooler in the 11-13th centuries. It is also England and summer
only. The galling thing is, it does look like the IPCC Figure!!!!!!
When Tom sent the figure, he added this text (see below).
The figure looks like Figure 30 (I've not scanned this one), but will,
from his 1982 (reprinted in 1985 and 1995) called Climate History
and the Modern World. This figure has series for the year, JJA and
DJF.
Someone tell me it isn't based on a Lamb diagram, please....
Phil
Tom Crowley said
we still don't have an adequat explanation as to how Jack "cooked up" that figure - I do
not believe it was purely out of thin air - look at the attached - which I used in the
Crowley-Lowery composite just because it was "out there" - I made no claim that it was the
record of record, but just that it had been used beforer.  the Lamb ref. is his book dated
1966.  I will have to dig up the page ref later.  Dansgaard et al. 1975 Nature paper on
Norsemen...etc used that figure when comparing what must have been their Camp Century
record - have to check that too - where the main point of that paper was that the timing of
Medieval warmth was different in Greenlandn and England!
25 years later my provocation for writing the CL paper came from a strong statement on the
MWP by Claus Hammer that the canonical idea of the MWP being warming than the present was
correct and that the 1999 Mann et al was wrong.  he kept going on like that I reminded him
that he was a co-author on the 1975 paper!  that is also what motivated to do my "bonehead"
sampling of whatever was out there just to see what happened when you added them all
together - the amazing result was that it looked pretty much like Mann et al.  ther rest is
history -- much ignored and forgotten.
I might also pointn out that in a 1996 Consequences article I wrote - and that Fred Singer
loves to cite -- Jack (who was the editor of the journal) basically shoehorned me into
re-reproducing that figure even though I didn't like it - there was not an alternative.  in
the figure caption it has a similar one to Zielinski except that it states "compiled by
R.S. Bradley and J.A. Eddy based on J.T. Houghton....so that puts a further twist on this
because it point to Houghton not Bradley/Eddy as the source.  Jack must have written that
part of the figure caption because I don't think I knew those details.
but we still don't know where the details of the figure came from - the MWP is clearly more
schematic than the LIA (actually the detailsl about timing of the samll wiggles in the LIA
are pretty good) - maybe there was a meshing of the Greenland and the England records to do
the MWP part - note that the English part gets cooler.  they may also have thrown in the
old LaMarche record - which I also have.  maybe I can schlep something together using only
those old three records.
tom
Stefan said
the reason why I started to worry about this is the attached graph. Recognise something?
- Used in school teaching in Germany, Austria and Switzerland, is on a website with
officially recommended teacher materials
- Used in university teaching in Germany
- Used in politics in Germany by people within the FDP.
Note the vertical axis label on that, by the way. The text that goes with it claims the
medieval warm period was 2-4 ºC warmer than today.
Climate sceptics material, of course.
Cheers, Stefan
13a7140.jpg
--
Prof. Phil Jones
Climatic Research Unit        Telephone +44 (0) 1603 592090
School of Environmental Sciences    Fax +44 (0) 1603 507784
University of East Anglia
Norwich                          Email    p.jones@uea.ac.uk
NR4 7TJ
UK
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References
1.


I think that this story could possible catch on and make headlines, so I
agree that we should be careful. But it's important that we bring the
*true* picture out, and it is best that this is done by RealClimate rather
than a sceptic site. The general scientific side of the IPCC report (i.e.
all the peer-reviewed papers ad the scientific theories) is still sound,
but to explain how *one* figure was shoe-horned into the report is harder
to defend. The sceptics may argue that the IPCC reports are political
after all, and this is also what it sounds like if governments 'hoisted
the national flag' by having it's own figures inserted last minute.
However, by providing an account of the 'evolution of the IPCC report
writing', we could possibly give the story a softer landing. E.g. how many
times of review the first report underwent as compared to the present
report. We should also put this in perspective - the report is large and
covers a wide range of topics, and most (all but our case?) is true to the
science. There are sometimes a few rotten apples in a good batch,
unfortunately. But the important part is that we don't accept rotten
apples and that we sort it out! Forthcoming and up-front. Another
important side is that this can provide a lesson for the scientific
communities.
Rasmus
> Phil, I fully agree. The point is not to blame anyone at all - at least
> my point was to track down the source in order to be able to show the
> skeptics (or in my special case, the school authorities) that this old
> graph is completely superseded and should not be used any more in
> teaching! And I also see your problem: what we are finding out now makes
> the IPCC  process look somewhat unsophisticated back in 1990, so it is a
>
> diplomatic conundrum how to be completely truthful in reporting this, as
>  we need to be as scientists, without providing the skeptics undue
> fodder  for attacking IPCC. But maybe we're too concerned - the skeptics
> can't  really attack IPCC easily in this case without shooting
> themselves in  the foot.
>
> Cheers, Stefan
>
> --
> Stefan Rahmstorf
> www.ozean-klima.de
> www.realclimate.org
--
Rasmus E. Benestad
Skype: rasmus.e.benestad
Rasmus.Benestad@physics.org or @met.no
mobile +47-41122662