The Global Warming Hockey Stick Gets Reviewed

Here is a bit from an excellent review by Matt Ridley of a new book The Hockey Stick Illusion by Andrew Montford.

A retired mining entrepreneur with a mathematical bent, McIntyre asked the senior author of the hockey stick graph, Michael Mann, for the data and the programs in 2003, so he could check it himself. This was five years after the graph had been published, but Mann had never been asked for them before. McIntyre quickly found errors: mislocated series, infilled gaps, truncated records, old data extrapolated forwards where new was available, and so on.

Not all the data showed a 20th century uptick either. In fact just 20 series out of 159 did, and these were nearly all based on tree rings. In some cases, the same tree ring sets had been used in different series. In the end the entire graph got its shape from a few bristlecone and foxtail pines in the western United States; a messy tree-ring data set from the Gaspé Peninsula in Canada; another Canadian set that had been truncated 17 years too early called, splendidly, Twisted Tree Heartrot Hill; and a superseded series from Siberian larch trees. There were problems with all these series: for example, the bristlecone pines were probably growing faster in the 20th century because of more carbon dioxide in the air, or recovery after “strip bark” damage, not because of temperature change.

This was bad enough; worse was to come. Mann soon stopped cooperating, yet, after a long struggle, McIntyre found out enough about Mann’s programs to work out what he had done. The result was shocking. He had standardised the data by “short-centering” them—essentially subtracting them from a 20th century average rather than an average of the whole period. This meant that the principal component analysis “mined” the data for anything with a 20th century uptick, and gave it vastly more weight than data indicating, say, a medieval warm spell.

Well, it happens. People make mistakes in science. Corrections get made. That’s how it works, is it not? Few papers get such scrutiny as this had. But that is an even more worrying thought: how much dodgy science is being published without the benefit of an audit by Mcintyre’s ilk? As a long-time champion of science, I find the reaction of the scientific establishment more shocking than anything. The reaction was not even a shrug: it was shut-eyed denial.

This sounds like a terrific book. It appears to have all the gory details of how a clique of "global warming" fanatics perpetrated a fraud on the scientific community and how the scientific community participated by letting itself be duped. A lot of people I respect still hold that the "climate science" is sound, but it is very, very clear to me that it isn't. Read the above review. It will give you the basic facts. I'm sure Montford's book will give you excruciating detail. Slowly but surely the fraud exposed by the release of the Hadley CRU e-mails, AKA "climategate", is making waves and changing minds.