The "Hide the Decline" Email Put in Context

Al Gore and other anthropogenic global warming believers claim the Climategate emails are taken out of context. Steve McIntyre at Climate Audit has blogged an excellent article that puts the Climategate "Hide the decline" email in context and it doesn't help the AGW position. In a nutshell, the IPCC wanted to use the historical proxy temperature change data in their Third Assessment Report, but they were concerned about the chart showing the wrong message since it declined in the late twentieth century.

A proxy diagram of temperature change is a clear favourite for the Policy Makers summary. But the current diagram with the tree ring only data [i.e. the Briffa reconstruction] somewhat contradicts the multiproxy curve and dilutes the message rather significantly… This is probably the most important issue to resolve in Chapter 2 at present.. (Folland, Sep 22, 1999, in 0938031546.txt)

Here is what the chart would have looked like.


Of course, this version wasn't used. The "Hide the decline" trick was implemented and the chart below was used.


It appears the context of the "Hide the decline" email was the IPCC wanted them to "Hide the decline." How is that for putting it in context?

From the new Climate Audit site:

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).

(More here)