The Hockey Stick Illusion

A review by Alastair McIntosh

originally published in the Scottish Review of Books, 14 August 2010

 The “hockey stick” is a graph showing the Earth’s temperature relatively constant for the past thousand years but then, like a hockey stick’s blade, rising sharply from about 1900 when human-induced greenhouse gas emissions seriously kicked in.

The Hockey Stick Illusion But according to A.W. Montford’s “definitive exposé”, it’s just not true.

 The captain of Montford’s “Hockey Team” is the renowned American climatologist, Michael Mann, and at least forty-two named co-conspirators from amongst acclaimed scientists.

 Their motivation? To keep the hockey-stick’s handle long and flat. Why? Because “the flatter the representation [before the upward swing] … the scarier were the conclusions” (p. 27).

 To generate the scare, and with it, win grant-grubbing political prestige, required massaging out the Medieval Warm Period (MWP) – an epoch that lasted 300 years until 1250, when Vikings swashbuckled Greenland and wine from home-grown grapes swilled the manor halls of England. Had the MWP been left in, claims Montford, the temperature curve for the past millennium would look more U-shaped. This would have diminished the case for human-induced global warming, obviating the urgency to discomfort ourselves by cutting CO2 emissions.

 Montford claims that the MWP was airbrushed out by cherry-picking and statistically steamrollering tree-ring data – one of the proxies used to reconstruct past planetary temperatures. Leaked East Anglia emails clinch the case. Bottom line: the UN’s Intergovernmental Panel on Climate has “proven itself to be corrupt, biased and beset by conflicts of interest…. There is no conceivable way that
politicians can justify this failing to their electorates. They have no choice but to start again” (pp. 390-1).

 But who is Montford, and what his sources? Andrew Montford, a chartered accountant with a BSc in chemistry from St Andrews University, is better known as the pseudonymous blogger, Bishop Hill – self-described as “the dissentient afflicted with the malady of thought.”

 His book’s opening paragraph tells how he learned the intricacies of climate science by reading Climate Audit – the blog of Canadian mining consultant, Steve McIntyre. He relates: “While some of the statistics was (sic) over my head … I wondered if my newly-found understanding of the debate would enable me to take on … a public duty to make the story more widely known” (p. 13).

 After posting a summary to Bishop Hill “my sleepy and relatively obscure website [turned] into a hive of activity, with thirty thousand hits being received over the following three days … saying nice things about what I had written [and] even an attempt to use my article as a source document for Wikipedia” (pp. 13-14).

 But McIntyre’s attack on Mann is strongly contested. A study from the Woods Hole Oceanographic Institution concluded that McIntyre had overplayed his hand. A German appraisal picked up “a
glitch” but “found this glitch to be of very minor significance.” An investigation by the US National Academy of Sciences, according to a report in Nature, “essentially upholds Mann’s findings.” And a review this year by Mann’s own university exonerated him, not necessarily of all error (which is inevitable in fast-evolving scientific fields), but of “any wrongdoing”.

 Even if Mann were guilty as charged by the climate change contrarians the hockey stick has been replicated by at least a dozen other studies. Above all, the MWP is probably a red herring. Its warming effect was probably more regional than global. A parallel would be our past winter which was exceptionally cold regionally in Europe, but globally the hottest that NASA has ever recorded.

 Montford’s analysis might cut the mustard with tabloid intellectuals but not with most scientists. Credibility counts. Mann has published over a hundred relevant contributions to scholarly journals compared, seemingly, with McIntyre, three, and Montford, nil. Meanwhile, Mann and his colleagues get on with refining their methods and datasets, publishing in such world-renowned journals such as Nature and Science.

 The Hockey Stick Illusion might serve a psychological need in those who can’t face their own complicity in climate change, but at the end of the day it’s exactly what it says on the box: a write-up of somebody else’s blog.

 At best it will help to keep already-overstretched scientists “on their toes”. At worst, it’s a yapping terrier worrying the bull; a spinning ball that cripples action, potentially costing lives and livelihoods.


Alastair McIntosh of the Centre for Human Ecology is a visiting professor at Strathclyde University and author of Hell and High Water: Climate Change, Hope and the Human Condition.



‘Mean-spirited scepticism’ – Richard Joyner


‘The Montford Delusion’ – Detailed analysis of Montford’s ‘arguments’ on the Real Climate website


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