From	Michael E. Mann	Date	Fri, 12 Apr 2002 12:32:33 -0400
To	Keith Briffa, Edward R. Cook
CC	Malcolm K. Hughes, Malcolm K. Hughes, Jan Esper, Tim Osborn, Phil Jones, Tom Crowley, ray bradley, Jonathan T. Overpeck, Scott Rutherford
Subject	Re: Your letter to Science
Whoaah...Please don't put words in my mouth Keith, especially such inflamatory word! I was not attributing the entirety of "spin" here (which is of a pretty massive scale) to you! And I said I think such "spin", where it has occurred, is EITHER sloppy OR disingenuous. You chose to assume I was talking about you in specific, and that I was attributing the latter rather than the former. My actual words don't bear this out. In the case of the Briffa & Osborn piece, I actually tend to believe that sloppiness was the main problem. In other cases of "spin" (e.g., the skeptics web pages of Daly and his ilk) it is most clearly disingenousnous...I don't equate you with Daly and those folks by any stretch of the imagination. Hopefully, you know that I respect you quite a bit as a scientist! But in this case, I think you were sloppy. And the sloppiness had a real cost... And as to whether or not your statements about IPCC are fair (I didn't use the word "disservice"!), I'll leave that to each to decide. But personally, I think they were unfair, because they opened up IPCC to criticism that is not merited by what is actually said or shown in the iPCC report. Other IPCC authors who have contacted me feel the same way, and perhaps there may be an official response on the part of IPCC authors. I don't know. But I agree that any further discussion ought to take place in the peer-reviewed literature, Mike At 05:09 PM 4/12/02 +0100, Keith Briffa wrote: I agree with the sentiments expressed by Tom . However, in his latest message Mike clearly says that our perspectives piece did the IPCC a disservice. He then accuses us of spinning the ECS paper to say that MBH is an underestimate of what it purports to be and that we have been sloppy and disingenuous. Frankly this is too much to take . I am not going to let this ruin my weekend so I wait until I have calmed down and find time next week to write a response. In the meantime I just wanted to note that I disagree with these comments. Perhaps the best place to continue this discussion is in the peer review literature. Keith At 11:11 AM 4/12/02 -0400, Michael E. Mann wrote: Ed and others, I thought I too should chime in here one last time... I'll leave it to you, Malcolm, Keith and others to debate out the issue of any additional uncertainties, biases, etc. that might arise from RCS in the presence of limited samples. That is beyond my range of expertise. But since this is a new and relatively untested approach, and it is on the basis of this approach that other estimates are being argued to be "underestimates", we would indeed have been remiss now to point this out in our letter. The wording "perilous" perhaps should be changed, by I very much stand by the overall sentiment expressed by Malcolm in our piece with regard to RCS. One very important additional point that Malcolm makes in his message is that conservative estimates of uncertainties, appropriate additional caveats, etc. were indeed all provided in MBH99, and I have always been careful to interpret our results in the context of these uncertainties and caveats. IPCC '2001 was careful to do so to, and based its conclusions within the context of the uncertainties (hence the choice of the conservative term "likely" in describing the apparently unprecedented nature of late 20th century warmth) and, moreover, on the collective results of many independent reconstructions. Briffa & Osborn would have you believe that IPCC '2001's conclusions in this regard rested on MBH99 alone. Frankly, Keith and Tim, I believe that is unfair to the IPCC, whether or not one cares about being fair to MBH or not. What is unfortunate here then is that Esper et al has been "spun" i to argue that MBH99 underestimates the quantity it purports to estimate, full Northern Hemisphere annual mean temperature. Given the readily acknowledged level of uncertainty in both estimates, combined with the "apples and oranges" nature of the comparison between the two (which I have sought to clarify in my letter to Science, and in my messages to you all, and the comparison plot I provided), I believe it is either sloppy or disingenuous reasoning to argue that this is the case. The fact that this sloppiness also readily serves the interests of the skeptics is quite unfortunate, but it is indeed beside the point! It would probably also be helpful for me to point out, without naming names, that many of our most prominent colleagues in the climate research community, as well government funding agency representatives, have personally contacted me over the past few weeks to express their dismay at the way they believe this study was spun. I won't get into the blame game, because there's more than enough of that to go around. But when the leaders of our scientific research community and our funding managers personally alert us that they believe the credibility of our field has been damaged, I think it is time for some serious reflection on this episode. that's my final 2 cents, Mike _______________________________________________________________________ Professor Michael E. Mann Department of Environmental Sciences, Clark Hall University of Virginia Charlottesville, VA 22903 _______________________________________________________________________ e-mail: mann@virginia.edu Phone: (434) 924-7770 FAX: (434) 982-2137 [1]http://www.evsc.virginia.edu/faculty/people/mann.[2]shtml References 1. http://www.evsc.virginia.edu/faculty/people/mann.shtml 2. http://www.evsc.virginia.edu/faculty/people/mann.shtml