Policy Documents

Curry Blog Tackles ‘Hide the Decline’

James M. Taylor –
February 28, 2011

In politics, Reagan Democrats provide a good sample for determining whether moderate Democrats are breaking ranks on a particular issue. Clinton Republicans provide the flip side of this equation. In the global warming debate, Judith Curry might fit the bill of a Reagan Warmist (or Clinton Warmist, if you will). Curry, who is chair of the Georgia Tech school of Earth and Atmospheric Sciences, tends to side with the alarmists on global warming issues, but is open-minded, non-dogmatic, and will call out flaws in alarmist theories or tactics when she sees them.

With this in mind, there has been a very worthwhile discussion this past week on Curry’s blog, Climate, Etc. In a post titled Hiding the Decline, Curry writes, “To date, I’ve kept Climate Etc.  a ‘tree ring free zone,’ since the issues surrounding the hockey stick are a black hole for conflict…. However, two things this week have changed my mind, and I have decided to take on one aspect of this issue: the infamous ‘hide the decline.’”

The entirety of Curry’s Hiding the Decline blog post is very much worth reading, but here are the defining four paragraphs:

“There is no question that the diagrams and accompanying text in the IPCC TAR, AR4 and WMO 1999 are misleading.  I was misled.  Upon considering the material presented in these reports, it did not occur to me that recent paleo data was not consistent with the historical record.  The one statement in AR4 (put in after McIntyre’s insistence as a reviewer) that mentions the divergence problem is weak tea.

“It is obvious that there has been deletion of adverse data in figures shown IPCC AR3 and AR4, and the 1999 WMO document.  Not only is this misleading, but it is dishonest (I agree with Muller on this one).  The authors defend themselves by stating that there has been no attempt to hide the divergence problem in the literature, and that the relevant paper was referenced.  I infer then that there is something in the IPCC process or the authors’ interpretation of the IPCC process  (i.e. don’t dilute the message) that corrupted the scientists into deleting the adverse data in these diagrams.

“McIntyre’s analysis is sufficiently well documented that it is difficult to imagine that his analysis is incorrect in any significant way.  If his analysis is incorrect, it should be refuted.  I would like to know what the heck Mann, Briffa, Jones et al. were thinking when they did this and why they did this, and how they can defend this, although the emails provide pretty strong clues.  Does the IPCC regard this as acceptable?  I sure don’t.

“Can anyone defend 'hide the decline'?  I would much prefer to be wrong in my interpretation, but I fear that I am not.”

While Curry’s Climate, Etc. is worth visiting every day, her Hiding the Decline thread is a can’t-miss discussion.