Book Review: The Hockey Stick and the Climate Wars

The following is my review of The Hockey Stick and the Climate Wars, by Michael Mann - I read the Kindle edition (and sent him a few corrections for typos here and there).

As I was reading this first-person account of some of the most maddening episodes in modern times, I wondered to myself - what audience is this written for? How will some of the different players and bystanders react? Is Dr. Mann bringing on himself here yet another round of baseless attack from those who side with the most powerful entities human civilization has ever known?

I have no doubt the attacks will continue to intensify. If you hear about this book from some of the people, foundations and corporations that Mann names in it, please remember they have a very strong agenda: they don't want you to read it. If you find yourself sympathizing with one of these powerful entities, that means you need to read it, more than anybody else.

Thousands of blog posts are out there on the internet accusing Mann of fraud, hiding and mishandling data, and wilder claims about his purpose or morals. Not only is there no evidence for any of these things - every bit of them is a piece of manufactured falsehood - but reading Mann's account puts them in a particularly stark light. The "hockey stick", the iconic graph that launched those thousands of attacks, was not even in the original article that the recently graduated Mann and his coauthors submitted - the suggestion to include temperatures after 1980 from instrumental measurements was made by an anonymous reviewer. And the main scientific point of their paper wasn't the full average temperature (with error bars) from past centuries but a more nuanced look at regional variations and oscillations which Mann had a particular interest in. It was certainly a good idea to provide that comparison of recent change - but I sensed a kind of wistfulness in Mann's account. Why couldn't somebody else have been the zebra who had strayed form the herd with that striking graph?

But I'm not sure I like Mann's "Serengeti strategy" metaphor. Scientists vigorously battle one another on scientific grounds, they aren't herd animals at all. And the attacks are coming from what appears to be a highly coordinated team - the book never mentions "vast right-wing conspiracy" but, unnamed, it is everywhere, and towards the end Mann resorts to an unspecified "they" who stand in opposition to climate science. "They" would clearly take down the entire field of climate science if they could - in fact they have tried to more than once, with the "climategate" fiasco perhaps the clearest example. That wasn't an attack on single scientists one at a time, that was a coordinated campaign that spread doubt and distrust over the entire field, again completely baselessly as Mann very clearly conveys. But unfortunately we have as yet no proof of conspiracy here, no "smoking gun". The evidence surrounding the Wegman report episode - involving congress, McIntyre, and oil-industry funding seems particularly damning, but none of the players have admitted to or been convicted of anything as yet.

The book manages to avoid any equations, but it does get into quite complex scientific matters in several sections - important for full understanding of what was going on, but daunting for the uninitiated. Mann's explanation of the Principle Components Analysis procedure in particular involves several sample graphs that take some thought to understand. And I didn't find his comparison to Spearman and Burt's misapplication of factor analysis for IQ-cultural correlations particularly helpful - substituting one complex analysis issue for another doesn't really make it a good analogy, but maybe it is helpful for those already familiar with the IQ story.

Even though I've been following most of the story for several years now, there were some surprises in the science described in the book. I hadn't realized that Mann had hypothesized increased frequency of "La Nina" conditions in a warming world (the 2000's have indeed been dominated by La Nina's, perhaps confirming his idea). And his original interest specifically in natural variations and oscillations like the "AMO" is particularly ironic given the nature of the bulk of attacks on his work, claiming he distorted data in order to suppress natural variability!

The worst problem with the book is Mann's frequent reluctance to depart from the nuanced (and multisyllabic) vocabulary of the scientist. As a fellow scientist I have to sympathize, but I wonder when, for example, he proudly states his response to ABC's David Wright: "my job as a scientist is making sure that the public discourse is informed by an accurate understanding of the science." Can you really succeed at that with nuanced statements such as "Recent warmth, it now at least tentatively appeared, was unprecendented for nearly the past two millennia, and perhaps longer."? And why does he so love the word "exculpatory" in describing the many investigations spawned by "climategate" - wouldn't something more familiar like "innocent" be a better choice?

It would also have been nice to see a bit broader context - the temperature "hockey stick" is only one of dozens that show dramatic change in our living environment since the industrial revolution began. In that context, after you see the hockey sticks in CO2, energy use, land use, species loss, population, etc., seeing a "hockey stick" in temperatures would only be expected, not some surprise. Exponential growth inevitably leads to hockey-stick-like impacts wherever there is any effect at all - and that human emissions would have some effect on temperature has been expected for well over 100 years.

But those are minor points. The one truly uplifting thing in this account is the tremendous support Dr. Mann and other scientists who have suffered from these attacks have received from both the scientific community at large, their institutional leadership, and a variety of good and conscientious people in media, government, and other organizations. Dr. Mann and his colleagues' bravery and strength in the face of this relentless persecution is an inspiration to us all. Standing for truth against great power - I only hope they will long be honored by posterity for their selfless commitment to "accurate understanding" and those ideals which science, at its best, represents.


Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

> after you see the hockey

> after you see the hockey sticks in CO2, energy use, land use, species loss, population, etc.

...sea level...


If you think Mike is using difficult language now, you should read some of his early RealClimate posts... he has learned a lot over the years.

It is clear that this is a job that he didn't choose himself to take on, but he is dispatching it remarkably well for a scientist. Certainly better than I ever will. See his TED talk for instance:

He is quite clear here about the enemy. More so than in the book?

I'm waiting for the paper thing -- old-fashioned in that way