Saturday snark: a textbook for Vincent

By Gareth Renowden 01/02/2014


As Stoat points out, the IPCC has released the reviewers comments on the Working Group One second order draft report. And as you might expect, the IPCC’s favourite inexpert commenter, the New Zealand Climate “Science” Coalition’s very own Vincent Gray was busy reviewing their work. Here’s comment 1-549 from Chapter One (pdf) by Gray:

The records shown are not “observations” and they are not “temperatures”. They are also not “globally averaged. They are a set of multiple averages, subtracted from an overall average, compiled from a vaying non-standardised set of maximum an minimum temperature measurements at varying weather sations and ship measurements. They were previously treated as “Mean Global Temperature anomaly” The uncertainties attached to each figure are very great, individual temperature measurements are rarely accurate to better than one degree, so a claimed “trend” over 100 years of less than one degree has a very low level of statistical significance. [Vincent Gray, New Zealand] (all spelling from IPCC doc)

The response from the editors is a minor classic of its kind:

Rejected – The comment does not reflect the scientific understanding. The errors in individual observations are not additive; we are also doing relative analysis that eliminates many of the concerns about individual errors. The reviewer obviously has a limited understanding of the associated error evaluation for analysis of large datasets. See Chapter 2 for more on the evaluation of these datasets. Or maybe even read a basic textbook. (my emphasis)

For more on accuracy versus precision, and the statistical power of large numbers, this classic post by Tamino is well worth a read.

There are other minor gems to be found as the reviewers deal with Monckton (in the “general” section) and John McLean (seemingly everywhere). In fact McLean’s ubiquity suggests that he may have acceded to Gray’s throne as the man with most comments on a single IPCC report. But don’t expect me to add them all up, I do have a life…