I recently received a copy of how IPCC authors answered the review comments, including their answers to the requirement of one reviewer that the deleted Briffa data be restored (and an explanation given for the inconvenient bits.) You may recall the observation of one reader in the discussion of Swindle, the reader observing:
If a practising scientist selected a 1987 data set over more recent versions, failed to cite it correctly, altered the appearance of the data without a clear explanation and didn’t include the data from the last 20 years then I think we’d all be asking serious questions about their professionalism.
I observed that there had been a serious alteration of the Briffa et al 2001 reconstruction in which diverging post-1960 values were simply chopped off. One of the IPCC 4AR reviewers called for the deleted post-1960 values to be shown both for Briffa et al 2001 and Rutherford et al 2001. Here’s how the authors responded. It’s pretty amazing, maybe even “gobsmacking”.
Reviewing the bidding first. I recently discussed the truncation of Briffa et al 2001 in the IPCC TAR spaghetti graph here. Below I show what the TAR spaghetti graph looked like and what it would look like without the Briffa truncation. See original post for clearer images. This was a cynical piece of data manipulation that would give pause to the most flagrant stock promoters. Actually, it would be illegal in a stock promotion.
An AR4 reviewer noticed the same thing in AR. He said (and, in this case there is no problem with reviewer copyright as the reviewer has permitted the comment to be posted at CA):
Show the Briffa et al reconstruction through to its end; don’t stop in 1960. Then comment and deal with the “divergence problem” if you need to. Don’t cover up the divergence by truncating this graphic. This was done in IPCC TAR; this was misleading. (Reviewer’s comment ID #: 309-18)]
A sensible comment, in my opinion. It’s a fundamental principle of public disclosure that you have to disclose any bad news. Promoters can then try to justify the bad news as best they can, but they can’t conceal it. The reviewer then made a similar comment, see below, about the deletion of the inconvenient divergence for Rutherford et al 2005. (OK, I was the reviewer. Neither Bradley nor Mann had a fit of conscience.)
If you do show Rutherford et al, you must show their values after 1960, as with Briffa et al 1960. Not to do so gives a very misleading impression. (Reviewer’s comment ID #: 309-20
Here’s what the IPCC authors said in defence of their deletion of the inconvenient bits.
Mr. McIntyre, you know better than this. The IPCC knows all and sees all and will not permit you to present actual author responses, which have accordingly been hereby deleted. Readers, if you wish further information on how IPCC authors justified the deletion of the bad bits, please write to FOIA at NOAA.gov and ask for the IPCC Working Group I Fourth Assessment Report, Expert and Government Review Comments on the Second-Order Draft. Mr McIntyre, you will not be warned again, ]
UPDATE: Subsequent to this post, reviewer comments were placed online here. The review comment said only:
Rejected – though note ‘divergence” issue will be discussed, still considered inappropriate to show recent section of Briffa et al. series