Context for 'hide the decline' discovered

Context for 'hide the decline' discovered
December 10, 10:10 PMEssex County Conservative ExaminerTerry Hurlbut


Steve McIntyre, the statistician who had been trying for years to win release of the raw data from the East Anglia Climatic Research Unit prior to the release of the CRU Archive, announced today that he had discovered the context for the most damaging and often-quoted e-mail in the archive.

Since the revelation of the Archive, Phil Jones, the author of the e-mail in question, has repeatedly complained that his remark was taken out of context. Other climatologists who support the proposition of anthropogenic global warming (AGW) have said the same.

Today McIntyre, on his blog Climate Audit (also noted by Jeff Id at The Air Vent), identified the context as a meeting of lead authors at the UN Intergovernmental Panel on Climate Change (IPCC). That meeting took place on September 1-3, 1999, in Tanzania, and the so-called "zero-order draft" of the IPCC's Third Assessment Report (TAR) was the key item on the agenda.

At issue was a proxy-temperature graph showing trends in temperatures for the preceding 1000 years. The first version of this graph, prepared initially by Keith Briffa, did show a significant decline in temperatures late in the twentieth century. The attendees at the IPCC meeting expressed, in no uncertain terms, their sentiment that this decline was an outlying result that ought to remain hidden, presumably from the broader scientific community and the public, in order to avoid what they feared would be a misconstruction of this decline.

Briffa summed up the situation in an e-mail, not present in the archive but quoted directly in another e-mail:

There is still a potential problem with non-linear responses in the very recent period of some biological proxies ( or perhaps a fertilisation through high CO2 or nitrate input) . I know there is pressure to present a nice tidy story as regards 'apparent unprecedented warming in a thousand years or more in the proxy data' but in reality the situation is not quite so simple. We don't have a lot of proxies that come right up to date and those that do (at least a significant number of tree proxies ) some unexpected changes in response that do not match the recent warming. I do not think it wise that this issue be ignored in the chapter.

Evidently Michael E. Mann (then at the University of Virginia) and Chris Folland (at the Hadley Centre, the HQ of the UK Met Office) thought that the issue was best ignored, or at least minimized. For example, Mann said this:

We demonstrate (through comparining [sic] an exatropical [sic] averaging of our nothern hemisphere patterns with Phil's more extratropical series) that the major discrepancies between Phil's and our series can be explained in terms of spatial sampling/latitudinal emphasis (seasonality seems to be secondary here, but probably explains much of the residual differences). But that explanation certainly can't rectify why Keith's series, which has similar seasonality *and* latitudinal emphasis to Phil's series, differs in large part in exactly the opposite direction that Phil's does from ours. This is the problem we all picked up on (everyone in the room at IPCC was in agreement that this was a problem and a potential distraction/detraction from the reasonably concensus viewpoint we'd like to show w/ the Jones et al and Mann et al series.

So, if we show Keith's series in this plot, we have to comment that "something else" is responsible for the discrepancies in this case.

By "opposite direction" Mann meant that the Briffa series showed the temperatures being cooler rather than warmer than the other series. By "something else" Mann seems to have meant an explanation of "processing" of the data.

Another significant part of Briffa's original e-mail contained an explicit acknowledgement by Briffa that the recently observed warming trends were not without precedent. Mann objected to this and insisted on what finally became the infamous "Hockey Stick" diagram.

Mann faces an inquiry by his current employers, Penn State University, for possible research misconduct. The exchange elucidated today by McIntyre would seem to indicate conduct to the prejudice of free scientific inquiry, that would have been violative of PSU policies had Mann been at PSU at the time.

Previous articles:

In answer to a putative climate scientist

PSU investigation proceeds amid silent campus protest

The Hockey Stick was never accurate--and CRU knew it

CRU director admits hacked files genuine

Hadley CRU hacked with release of hundreds of documents and e-mails