Continued from Part 1, Part 2 One more bit of review before we get to Ammann’s answer. As an excuse for not answering the request of the House Energy and Commerce Committee about the R2 statistic, Mann told them that his “colleagues and [himself] did not rely on this statistic” in the following terms: The […]
Continued from Ammann at AGU (#1). I’m going to give a fairly brief account of previous attempts to get the residual series and/or cross-validation R2 from Mann, including inquiries to Mann, N.S.F., through Nature, by Climatic Change, by Natuurwetenschap & Techniek and by the House Energy and Commerce Committee. As you will see, no one […]
Ammann made a presentation at the same AGU session as me, spending a considerable amount of time criticizing us — though with nothing new to say that we haven’t already rebutted here and in print. There was time for one question (AGU is fanatical about schedules) and I was recognized. So here’s my question to […]
Barton’s question 7d asked MBH about other verification statistics. We’ve discussed their withholding of the R2 statistic here, here and here. In our GRL article, we also pointed out that their 15th century reconstruction also failed the CE statistic, another verification statistic used in dendroclimatic studies [Cook et al, 1994]. Mann’s retort was that climatologists […]
I have previously discussed here and here Mann’s answer to the following question from the House Committee: "7 c. Did you calculate the R2 statistic for the temperature reconstruction, particularly for the 15th Century proxy record calculations and what were the results?" Mann stated: "My colleagues and I did not rely on this statistic in […]
Mann has just(July 2005) archived a fortran program at ftp://holocene.evsc.virginia.edu/pub/MANNETAL98/METHODS/multiproxy.f. {Update: see here] Here are my first thoughts on this.
I’m now completely file compatible with Wahl and Ammann. In terms of my algorithm, I had to tweak the procedure for scaling RPCs a little, but the RPCs themselves were identical. It took some patience to reconcile differing data setups. I archived results from a complete run-through from their base case a couple of days […]
What is ironic in Mann’s citation of Cook as authority that paleoclimatologists need not provide a range of verification statistics is that Cook et al. [2004] actually provide a suite of verification statistics, headed by the R2 statistic, which Mann et al. now object to.
Climate Audit 