The Mann et al 1998-99 reconstruction had “steps” (grandiosely called “experiments” by Mann), but the results of the individual steps were never archived, only the splice of 11 steps. For statistical analysis, one needs to have the residuals, which we requested in 2003. Mann refused. At this point in 2003, contrary to North’s allegations, Mann hadn’t provided any source code, any computer programs nor any interpretations of computer programs. All that he had provided us was a URL on his FTP site for the proxy data supposedly used in MBH – a data set that he later claimed was the “wrong” data set and which he deleted in Nov 2003 and a new version of the MBH proxy data was made public. At the point that the residuals were refused, Mann hadn’t spent more than a few minutes responding to requests from us.
The MBH residual series crop up in the Climategate Letters. In July 2003, Mann had sent CRU the very data [Sep 4, 2014 - actually only the 1902-1980 residuals] that he later refused to provide to us. (BTW Osborn also asked Mann for source code and interpretation of matters that he did not understand.) Mann made it very clear to Osborn that the residual series were provided in total confidence, that they were “dirty laundry” which he did not want to “fall into” the wrong hands.
Did Mann refuse to provide the residual series to us because answering our inquiries had taken up so much of his time that he stopped answering? Or was there some other reason?
Michael Mann to Tim Osborn, CRU, July 2003
Attached are the calibration residual series for experiments based on available networks back to: AD 1000, AD 1400, AD 1600… You only want to look at the first column (year) and second column (residual) of the files. I can’t even remember what the other columns are! mike
p.s. I know I probably don’t need to mention this, but just to insure absolutely clarify on this, I’m providing these for your own personal use, since you’re a trusted colleague. So please don’t pass this along to others without checking w/ me first. This is the sort of “dirty laundry” one doesn’t want to fall into the hands of those who might potentially try to distort things…
McIntyre to Mann, December 2003 cc NSF
In MBH98 and MBH99, you refer to analyses of residuals carried out in these studies. Could you please provide me with (a) preferably, a FTP location for the residual series, together an FTP reference for the program generating the residuals; or, (b) in the absence of such FTP location, an email enclosing this information. Your analysis of these residuals was used to estimate confidence intervals in an influential scientific paper.
David Verardo Director, Paleoclimate Program, US National Science Foundation, Dec. 17, 2003 preemptively permitting Mann not to disclose his “dirty laundry”:
Dr. Mann and his other US colleagues are under no obligation to provide you with any additional data beyond the extensive data sets they have already made available. He is not required to provide you with computer programs, codes, etc. His research is published in the peer-reviewed literature which has passed muster with the editors of those journals and other scientists who have reviewed his manuscripts. You are free to your analysis of climate data and he is free to his.
McIntyre to Ziemelis of Nature, August 2004
we are writing to reiterate long-standing requests for data and results from MBH98, which we have already communicated on several occasions. You had stated that these requests would be resolved in the new SI, but unfortunately this is not the case. While you are undoubtedly weary of this correspondence, our original request for disclosure was reasonable and remains reasonable. It is only the unresponsiveness of the original authors that is placing a burden on you and your associates. Some of these items have been outstanding for 7 months. They were not attended to in the new SI and need to be dealt with promptly. … In particular, we still seek … the results of the 11 “experiments” referred to in MBH98, including: (b) the NH temperature reconstruction (11 series from the start of each calculation step to 1980); (c) the residuals (11 series from the start of each calculation step to 1980)… Since their claims of skill in reconstructing past climates depend on these “experiments” and their estimation of confidence intervals is based on the residual series, it is unnecessary to explain why these data are of interest. Again, we have repeatedly requested this data.
Ziemelis to McIntyre, Sept 2004
And with regard to the additional experimental results that you request, our view is that this too goes beyond an obligation on the part of the authors, given that the full listing of the source data and documentation of the procedures used to generate the final findings are provided in the corrected Supplementary Information. (This is the most that we would normally require of any author.)
Following paragraphs moved from first two paragraphs to appendix on Sep 4, 2014.
Here is Gerald North, Dec 1, 2009 purporting to justify data refusals by the Team:
McIntyre entered the fray by asking for data from Mann and his coauthors in about 2000 [actually 2003, but who expects accuracy from climate scientists]. As I understand it they complied, but the more they complied the more he wanted. He began to make requests of others. He sometimes not only wanted data, but computer programs. When he could not figure out how the programs worked he wanted help. From what they tell me this became so irritating that they stopped answering his emails.
North is giving public credence to this increasingly popular meme among climate scientists. Virtually everything in North’s meme is untrue. Rather than provide a detailed rebuttal, let me suggest an another and far more plausible alternative. Mann and others didn’t want to give data to potential critics. Let me show an actual situation, one where the Climategate Letters provide much new information.