The Hockey Stick Illusion;Climategate and the Corruption of Science (Independent Minds) [Paperback]

This is a superb review of the story of the hockeystick, the temperature reconstruction which was supposed to show that late 20th century temperatures were unprecedented for at least 1,000 years and which was highlighted in the third IPCC report in 2001. What Montford does in this book is take us through Steven McIntyre's attempt to reproduce the original result of Michael Mann and the controversy that followed. His account is very well written and it reads like a detective story. The technical details of the debate are clearly explained even though there is no heavy mathematics or statistics. He tells the story chronologically and gives a good feel of what people on both sides of the debate actually said at the time (and there are plenty of references as well as judicious quotes form all sides. I have been following this debate for the past five years or so. To my mind this gives as clear an account of the debate as we are likely to see. What is now clear is that the Mann conclusions, far from being based on coherent evidence across a geographical widespread range of proxies all showing similar patterns across the Northern hemisphere, were based on a tiny subset of proxies, bristlecone and foxtail pines, from California whose anomalous 20th century growth was almost certainly not caused by high temperature. The apparently broad evidence was an illusion created by an eccentric implementation of a standard statistical technique called principal components analysis. Mann's version of this (which appears to be his own creation) effectively mined his hundred plus proxies for any which had hockeystick shapes and then gave them huge weight in the analysis. What is worrying about all this is not so much the fact that a paper is wrong. It is the failure to admit this when it is perfectly clear that it is wrong. Montford documents the evasions of debate and the consistent misrepresentation of what McIntyre and McKitrick actually said, as well as multiple refusals of access to data and clear descriptions of what had actually been done. By the time of the 2006 Wegman report it was clear that the hockeystick was broken, but it seems too much had been invested in it for people in paleoclimate to admit outright that it was just wrong. Montford tells this story too and documents the shenanigans surrounding the fourth Assessment Report of the IPCC. But rather than me attempting to condense the book into a paragraph I urge people to buy and read this excellent account. Note that it was largely written before the emails from CRU became public, though there is a final chapter dealing quickly with them. What is remarkable is how much of the story was already known to people who had been following the debate, but also the lengths people were prepared to go to try and stifle proper debate. For me the cover-up of the story has been a bigger influence in turning me sceptical than the mere fact of the hockey stick being wrong.

The flood of blogs and blog-postings on climate threatens to overwhelm the concerned citizen wanting to deepen his or her understanding of climate topics and policies. This book is just what is required to keep one's head above the surface in at least one corner (?) of this tumultuous deluge. By adding a very helpful and well-written commentary to previously published exchanges of emails between critical commentators and climate conspirators (an emotive description, my choice, but readily justified by the CRU emails and software code exposed towards the end of last year), as well as blogposts and articles published in the regular media. Some more extended sections help explain technicalities, not least statistical concepts such as R2 and PC analysis. An important feature of the book is the naming of names, indeed there is a 'dramatis personae' at the start of the main participants, but others such as the chap who became the conspirators friend by censoring Wikipedia articles on climate (not mentioned in the book) are given passing mention. The roles of the two blogs 'RealClimate' and 'Climate Audit' are well covered. The formed was lavishly funded by a leftwing PR agency, the latter was created by self-funded commentators and analysts taking an independent and refreshingly critical view of the statistical and other assertions of what I would be inclined to call 'professional climate alarmists'. All in all, a heartening piece of work. Heartening to see ordinary, albeit talented, people questioning the sermons, admonitions, analyses, and alarums of a remarkably influential coterie of climate scientists and political agitators who managed through the IPCC to have an impact utterly disproportionate to the merits of their case or of their morals.

This is an excellent book not only providing a complete picture but well written. I think it is also an important book as it tells a story of a science discipline gone wrong. The quote from Esper tells it all - "the ability to pick and choose which samples to use is an advantage unique to dendroclimatology". THIS IS NOT SCIENCE! This book has provided me with many details which has helped me understand previous papers I had read. For example I never understood how Mann's original papers ever passed the review process as they were so muddled (and I am being kind here) and the NAS report why was it so ambivalent - well now I know! This book is accessible to all especially the layman who is concerned that he/she may not understand complicated science. I think it is important that as many people read it and understand the story of people behaving badly. To quote Einstein "try not to become a man of success but rather to become a man of value" and McIntyre has certainly shown himself to be a man of value.