Congress Asked If Climate Science is Solid ...

Thu, 2006-07-20 18:26Richard Littlemore
Richard Littlemore's picture

Congress Asked If Climate Science is Solid ...

… and the scientists it selected to answer the question said yes.


Cherrypicking, cherrypicking.

Or perhaps you missed the Congressional hearing also held his week in which the hockey stick met its well-deserved death?

It is hard to reconcile this website's supposed opposition to "spin" with posts that cherrypick as much as this one does.

Cherrypicking? The overwhelming message of the Congressional hearings we are referring to in this post is: global warming is happening, we are the cause of it, get on with solutions. The quote I thought summed up the current situation best was Dr. Judith Curry, a 25 year climate system researcher from Georgia Tech:

"In addition to my own personal research experiences in the Arctic, a series of national and international assessments undertaken by the Intergovernmental Panel on Climate Change (IPCC), the U.S. National Academies, and the U.S. Climate Change Science have made it very difficult to maintain a credible position of scientific skepticism regarding the influence of humans on global warming."



As far as Mann's hockey stick study and the recent Wegman report, that is one study out of thousands and decades of research that provide evidence that global warming is happening and it is caused by us. We are not cherrypicking by any stretch of the imagination. Those few who seem to think that b/c the conclusions of the "hockey stick" have been brought into question, that this somehow brings into question the overwhelming consensus on climate change and its causes, are the ones who should be accussed of cherry-picking.




The hockey stick was formed by the use of carefully selected proxies. The selection criteria was that certain proxies have a clear "signal".

The tree ring "signal" is assumed to be temperature, in spite of the fact that dendrochronology (tree ring) experts have written extensively that tree rings do not provide a linear temperature response. In particular, some of the tree ting proxies emphasized by Mann do not have a clear temperature response.

Then Mann manipulated his data with a computer program to perform Principal Component Analysis (PCA) on the proxies. This is the first time that scientists are aware of the use of PCA in the natural sciences.

The computer program weighted certain proxies more than others based on their shape.

Dr. Wegman, the head of statistics for the National Academy of Science, pointed out that you could use noise with this procedure and get a very nice hockey stick graph.

There are not thousands of of studies which support Mann's hockey stick, although there are quite a few papers by Mann's co-authors and grad students which do support it. These supporting studies use primarily the same limited number of proxies which Mann used in his papers. Out of the thousands of proxies which they could have chosen, these supporting studies studies all seemed to emphasize the same 15 to 20 proxie sets with a clear "signal". Don't you find this odd?

Perhaps this is not cherry picking. Perhaps it is something else, however it seems to be strange science.

What did you think of John Christy's testimony at the hearing? He seemed pretty clear that the climate models are not proving true. His conclusion was rather compelling, too, I thought.

For your convenience, here's a link to his written testimony

or you can download all the written testimonies from the Committee website: