IPCC and the “Trick”

Steve McIntyre
Much recent attention has been paid to the email about the “trick” and the effort to “hide the decline”. Climate scientists have complained that this email has been taken “out of context”. In this case, I’m not sure that it’s in their interests that this email be placed in context because the context leads right back to a meeting of IPCC authors in Tanzania, raising serious questions about the role of IPCC itself in “hiding the decline” in the Briffa reconstruction.

Relevant Climategate correspondence in the period (September-October 1999) leading up to the trick email is incomplete, but, in context, is highly revealing. There was a meeting of IPCC lead authors between Sept 1-3, 1999 to consider the “zero-order draft” of the Third Assessment Report. The emails provide clear evidence that IPCC had already decided to include a proxy diagram reconstructing temperature for the past 1000 years and that a version of the proxy diagram was presented at the Tanzania meeting showing the late twentieth century decline. I now have a copy of the proxy diagram presented at this meeting (see below).