I’ve posted on several occasions on the deletion of the “inconvenient” section of the Briffa reconstruction. Now that the review comments are online, I want to reprise this, just so you can understand the IPCC process a little better. This repeats some earlier material.
As an IPCC reviewer, I
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)]
In response, IPCC section authors said:
Rejected — though note divergence’ issue will be discussed, still considered inappropriate to show recent section of
Briffa et al. series.
Once again, here’s what they were deleting and what they felt was “inappropriate” to show the public – the post-1960 decline in the Briffa index. (I’ve shown the IPCC TAR version here but the same deletion is made in AR4). By deleting the adverse segments, they enhance the rhetorical impression of the remaining series. Any mining promoter that did this would be in trouble with the securities commissions.