Skip to content

The “Hockey Stick” is shorthand for two ways of thinking about global warming. For anti-carbon crusaders, a 1998 paper and its 1999 follow-up showing temperatures over the past 1,000 years demonstrated the terrible and immediate threat that man poses to the planet. (A graph accompanying the paper was nicknamed the “hockey stick,” as it shows a sharp upswing in the 20th century.) For global-warming skeptics, though, the graph and the name are prime examples of the overblown claims and sloppy science behind much of climatology.

Michael Mann, a Penn State professor, was the lead author of those studies, which became famous in 2001 when they were included in an assessment report by the United Nations Intergovernmental Panel on Climate Change (IPCC). He has since become one of the loudest advocates of the anti-carbon agenda, energetically blogging and tweeting about the need for urgent U.S. emissions reduction and global cap-and-trade. It’s not surprising that he is also a prime target for global-warming skeptics, who argue that establishing statistically significant temperature trends from proxy data is tricky and that Mr. Mann’s certainties involve, at best, debatable speculations and questionable math.

“The Hockey Stick and the Climate Wars” is the story of both Mr. Mann and his graph. But rather than a chronicle of research and discovery, it’s a score-settling with anyone who has ever doubted his integrity or work: free-market think tanks, industrialists, “scientists for hire,” “the corruptive influence of industry,” the “uninformed” media and public. So, a long list.

The trouble, as Mr. Mann sees it, is that while his own errors have been honest and minor, his detractors’ amount to “disinformation.” “Given the complexities,” he writes, “it’s easy enough to make mistakes. For those with an agenda, it is even easier to overlook them or, worse, exploit them intentionally.” He writes that the legitimate scientific and mathematical quibbles are compounded by “the here-and-now incentive” of the media. “Incremental refinements may seem dull and uninspiring to the lay public, but controversy sells. . . . It is not difficult to see why confused observers attempting to follow scientific developments would throw up their hands, resigned to the notion that all we can safely conclude is that ‘the scientists don’t agree.’ “

Thus through the combination of fossil-fueled machinations and a public that can’t handle the nuance, Mr. Mann and the truth have become victims of the “most malicious of the assaults on climate science.”

The Hocky Stick and the Climate Wars

By Michael E. Mann
(Columbia, 395 pages, $28.95)

Yet in its treatment of the actual science, “The Hockey Stick” is structured not unlike IPCC reports. Mr. Mann synthesizes selected work in the field and carefully accounts for uncertainties—the shortcomings of climate modeling, the statistical pitfalls of paleoclimatology, the unknowns surrounding the role of clouds—before lapsing into sound bites: “The key question is, can the model be shown to be useful? Can it make successful predictions? Climate models had passed that test with flying colors by the mid-1990s.”

And like IPCC reports, checking endnotes and references is crucial. In his chapter “Climate Science Comes of Age,” Mr. Mann writes that there was “increasing recognition by the mid-1990s” that another 1.5°C (2.5°F) warming beyond current levels “could represent a serious threat to our welfare.” It turns out that “increasing recognition” refers to a benchmark agreed to by a group of EU ministers in 1996, which Mr. Mann cites along with his own 2009 paper.

The book’s climax is a recounting of the 2009 leak or hack of emails and other documents written by Mr. Mann and his associates (and funneled through the University of East Anglia’s Climatic Research Unit). The correspondence, along with a second trove released in 2011, highlighted the patchwork behind IPCC science. The leading lights of publicly funded climatology appeared to be brainstorming to pressure journals and review boards to suppress work that challenged their theories, trading tips on how to avoid public-information requests and planning how to present their findings so as to best further “the cause.”

In his book, Mr. Mann dubs the unauthorized release of his emails a “crime” and claims that the ensuing “witch hunt” constituted “the most malicious” of “attack after vitriolic attack against us” by the “corporate-funded denial machine.”

Yet for all his caviling about “smear campaigns,” “conspiracy theorists” and “character assassination,” Mr. Mann is happy to employ similar tactics against his opponents. Patrick Michaels, former president of the American Association of State Climatologists and a past program chair of the American Meteorological Society’s Committee on Applied Climatology, is introduced as “a prominent climate change contrarian at the University of Virginia primarily known for his advocacy for the fossil fuel industry.” (Nowhere does Mr. Mann explain why a scientist might be more easily corrupted by a check from, say, a coal company than by one from a politically controlled institution.)

Just this February, Mr. Mann took to the Daily Kos to praise the theft of internal documents from the free-market Heartland Institute for offering “a peek behind the curtain of industry-funded climate change denial.” It was revelatory, but not in the way he thought. Hours after Mr. Mann posted his online musings, the much-decorated hydroclimatologist Peter Gleick (2003 MacArthur fellow, adviser to the EPA and, until recently, chairman of the American Geophysical Union’s task force on scientific ethics) confessed to the Heartland theft. Apologizing for his actions, he wrote that he had been “blinded by my frustration with the ongoing efforts—often anonymous, well-funded, and coordinated—to attack climate science and scientists.”

Mr. Mann closes “The Hockey Stick” with a passionate call for more scientists to join him “on the front lines of the climate wars.” “Scientific truth alone,” Mr. Mann writes, “is not enough to carry the day in the court of public opinion.” It would be “irresponsible,” he says, “for us to silently stand by while industry-funded climate change deniers succeed in confusing and distracting the public and dissuading our policy makers from taking appropriate actions.” These are unfortunate conclusions for a scientist-turned-climate-warrior whose greatest weakness has always been a low estimation of the public intellect.