Climate cuttings 19

- Bishop Hill blog - Climate cuttings 19

The Paleoclimate Reconstruction Challenge is firing lots of interest. If reconstructions of past climate are going to be based on sound science in future, it will be a big step forward. A kick-off conference was held (behind closed doors) in Trieste but some of the papers presented have fortunately found their way onto the internet. One, by the CRU's Keith Briffa, was very candid about the problems of verification of tree ring regressions, describing them as "of limited rigour", and that they tell us "virtually nothing about the validity of long-timescale climate estimates". Strangely, while writing the paleoclimate chapter of the IPCC report, he rejected any such criticism out of hand. The IPCC's final report talked of "the general strength of many such calibrated relationships, and their significant verification using independent instrumental data."