I was going to extract some more e-mail references to Mike’s hokey hockey stick reconstruction but a correspondent informs there’s plenty to be found online already
Here’s the appropriate theme from Global Warming Questions (I’m afraid I don’t know who to credit or hat-tip but do feel free to make yourself known):
Climate scientists were aware that the ‘hockey stick’ reconstruction was wrong and that criticism of it by Steve McIntyre and others was valid
3373.txt: Raymond Bradley: “ Furthermore, the model output is very much determined by the time series of forcing that is selected, and the model sensitivity which essentially scales the range. Mike only likes these because they seem to match his idea of what went on in the last millennium, whereas he would savage them if they did not. Also–& I’m sure you agree–the Mann/Jones GRL paper was truly pathetic and should never have been published. I don’t want to be associated with that 2000 year “reconstruction”. ” This refers to a 2003 paper “Global surface temperatures over the past two millennia” by Mann and Jones, that shows ‘hockey stick’ temperature graphs and was used by the IPCC in its 2007 report.
0435.txt: Ed Cook, on the same Mann & Jones paper: “ I am afraid the Mike and Phil are too personally invested in things now (i.e. the 2003 GRL paper that is probably the worst paper Phil has ever been involved in – Bradley hates it as well), ”
1527.txt: Dendrochronologist Rob Wilson writes: “ There has been criticism by Macintyre of Mann’s sole reliance on RE, and I am now starting to believe the accusations. ”
4241.txt: Rob Wilson again: “ The whole Macintyre issue got me thinking…I first generated 1000 random time-series in Excel … The reconstructions clearly show a ‘hockey-stick’ trend. I guess this is precisely the phenomenon that Macintyre has been going on about. ”
4369.txt: Tim Osborn says “ This completely removes most of Mike’s arguments… ” and Ed Cook replies “I am afraid that Mike is defending something that increasingly can not be defended. He is investing too much personal stuff in this and not letting the science move ahead.”
4758.txt: Tim Osborn: “ Because how can we be critical of Crowley for throwing out 40-years in the middle of his calibration, when we’re throwing out all post-1960 data ‘cos the MXD has a non-temperature signal in it, and also all pre-1881 or pre-1871 data ‘cos the temperature data may have a non-temperature signal in it! “
2346.txt: Osborn: “ Also, we set all post-1960 values to missing in the MXD data set (due to decline), and the method will infill these, estimating them from the real temperatures – another way of “correcting” for the decline, though may be
not defensible! ”
2009.txt: Keith Briffa: “ I find myself in the strange position of being very skeptical of the quality of all present reconstructions, yet sounding like a pro greenhouse zealot here! ”
3994.txt: John Mitchell (Met Office) commenting on draft IPCC report: “ Is the PCA approach robust? Are the results statistically significant? It seems to me that in the case of MBH the answer in each is no. ”
1104.txt: Heinz Wanner: “ I was a reviewer of the IPCC-TAR report 2001. In my review which I can not find again in its
precise wording I critcized the fact that the whole Mann hockeytick is being printed in its full length in the IPCC-TAR report. In 1999 I made the following comments:
1. The spatial, temporal (tree-ring data in the midlatitudes mainly contain “summer information”) and spectral coverage and behaviour of the data is questionable, mainly before 1500-1600 AD.
2. It is in my opinion not appropriate already to make statements for the southern hemisphere and for the period prior to 1500 AD.
My review was classified “unsignificant” ”
0497.txt: Jones to Mann in 1999: “ Keith didn’t mention in his Science piece but both of us think that you’re on very dodgy ground with this long-term decline in temperatures on the 1000 year timescale. What the real world has done over the last 6000 years and what it ought to have done given our understandding of Milankovic forcing are two very different things. ”
0562.txt: Simon Tett (Met Office), discussing revising a paper: “ No justification for regional reconstructions rather than what Mann et al did (I don’t think we can say we didn’t do Mann et al because we think it is crap!) ”.
2383.txt: Tim Barnett in 2004: “ maybe someone(s) ought to have another look at Mann’s paper. His statistics were suspect as i remember… ”
1656.txt: Douglas Maraun (UEA): “ I think, that “our” reaction on the errors found in Mike Mann’s work were not
especially honest. ”
4005.txt: Osborn: “ Also we have applied a completely artificial adjustment to the data after 1960, so they look closer to observed temperatures than the tree-ring data actually were ”
4133.txt: David Rind (NASA GISS): “ what Mike Mann continually fails to understand, and no amount of references will solve, is that there is practically no reliable tropical data for most of the time period, and without knowing the tropical sensitivity, we have no way of knowing how cold (or warm) the globe actually got. ”
1738.txt: Tree expert Rod Savidge writes: “ What troubles me even more than the inexactness attending chronological estimates is how much absolute nonsense — really nothing but imaginative speculation — about the environment of the past is being deduced from tree rings and published in dendrochronology journals. ”
3219.txt: Savidge again: “ As a tree physiologist who has devoted his career to understanding how trees make wood, I have made sufficient observations on tree rings and cambial growth to know that dendrochronology is not at all an exact science. Indeed, its activities include subjective interpretations of what does and what does not constitute an annual ring, statistical manipulation of data to fulfill subjective expectations, and discarding of perfectly good data sets when they contradict other data sets that have already been accepted. ”
The following sequence of emails relate to a paper ‘The Team’ are preparing to respond to a paper by Soon & Baliunas (2003). They know that much of the material in their own paper is wrong. See here for more detail.
0682.txt: “ By chance SB03 may have got some of these precip things right, but we don’t want to give them any way to claim credit. ” “ There is much other evidence that it is precip that is the driver ”.
0285.txt: “ We also don’t show it after 1940. I agree this has to be made very clear in the caption ”. This data deletion never was made clear in the caption, leading to a repetition of the notorious “hide the decline” trick.
4207.txt: “ You commented that the Chinese series of Yang et al (GRL 2002) looked weird. Well, that’s because it’s crap–no further comment on what stuff gets into GRL! You appear to have used their so-called “complete” China record. You really should consider what went into this –2 ice core delta 18O records of dubious relationship to temperature … You just shouldn’t grab anything that’s in print and just use it ‘cos it’s there—that just perpetuates rubbish. This series needs to be removed from Figure 2 in the EOS forum piece ” (the suspect paper was not removed).
5027.txt: “ I find it somewhat ironic that it should be replaced with the latest (Mann and Jones) series that contains the same three series plus a mixture of other far more dubious (not to say bad ) series ”
2023.txt: “ I also believe some of the series that make up the Chinese record are dubious or obscure , but the same is true of other records Mann and Jones have used … There are problems (and limitations ) with ALL series used. ”
4712.txt: “ I suggest adding the following to the end of the Figure 2 caption: “….. Note that individual series are weighted according to their quality in forming a composite hemispheric-scale time series.” The word ‘quality’ here has been chosen carefully — as something that is deliberately a bit ambiguous. ” (this was not done).
0539.txt: “ IT IS A DIFFICULT CALL — WHETHER TO DUMP SERIES THAT HAVE NO SIGNIFICANT LINK TO TEMPERATURE AND WHICH ARE, AS WELL, DUBIOUS ON A PRIORI GROUNDS ”
[See also Climategate 1 email 1024334440.txt where Briffa describes Mann's work as 'crap' and Cook agrees.]