Michael Mann says scientists have lost control of the public message about climate change

By Alexandra Witze

Web edition: November 7, 2010

NEW HAVEN, Conn. — Like evolutionary science in times past, climate science is now the target of “an elaborate P.R. campaign” to discredit researchers and their findings, says one of the scientists at the heart of the battle.

Michael Mann, a climate researcher at Pennsylvania State University in State College, is perhaps best known for his work on the “hockey stick” reconstruction of past climate. Like a piece of sports equipment turning up sharply at the end, this graph shows global surface temperatures remaining fairly constant for the last millennium, then sharply upticking over the past several decades. The reconstruction is not the strongest evidence for man-made global warming, Mann notes, but it became something of a poster child when it was featured in a summary for policy makers in the 2001 report from the Intergovernmental Panel on Climate Change (IPCC).

Late the morning of November 7, Mann stepped in front of a crowd of reporters just off the campus of Yale University, as part of a plenary panel at the annual Council for the Advancement of Science Writing meeting. It was a friendly crowd, most of whom had spent years covering the overwhelming scientific evidence that greenhouse gases put into the atmosphere by human activities are causing global temperatures to heat up.

(Yet “scientific consensus” has different meanings to different people, the reporters learned later that afternoon. Dan Kahan, a law professor at Yale, has shown that people’s cultural backgrounds shape what they think “most scientists agree on.” In other words, people usually think scientists are telling them what they already believe.)

Mann pulled out all stops in addressing the so-called Climategate scandal of a year ago, involving e-mails hacked from the Climatic Research Unit at the University of East Anglia in England, and the current attempts of Virginia's attorney general to get the University of Virginia to produce correspondence of Mann’s while he was on faculty there between 1999 and 2005.

After running through the evidence supporting human-caused climate change, Mann concluded that “there’s not just a hockey stick — there’s a hockey league.” Some scientific uncertainties do remain about climate change, such as the precise effects of clouds in a changing climate. “There are legitimate uncertainties,” Mann said, “but unfortunately the public discourse right now is so far from scientific discourse.”

Quite possibly the modern low in public understanding of climate science was the November 2009 hacking of the East Anglia e-mails. They showed science at its wartiest: researchers, including Mann, being critical and brusque as the 2007 IPCC report was coming together. On Sunday, Mann charged that the release of the e-mails had been deliberately targeted to sabotage the Copenhagen climate negotiations, which were to take place just a few weeks later.

No one has ever been charged in the East Anglia hacking, and the Copenhagen conference ended without a meaningful climate deal to succeed the greenhouse-gas–limiting Kyoto protocol. The next round of United Nations climate talks begins November 26 in Cancun, Mexico.

Clearly frustrated, Mann told the science reporters about how he saw the mainstream media as having abandoned their critical faculties in reporting the East Anglia story. Similar frustrations, he said, led him and a group of other climate experts to found the collective blog Realclimate.org several years ago, meant to bring timely and relevant climate information direct from scientists to the public.

I’ve seen Mann in this frame of mind before; several years ago he testified in front of some of his staunchest critics at a National Academy of Sciences panel set up to review the hockey stick work. The jaw I saw clenched back then seemed not to have loosened, even when the audience was a group of friendly journalists rather than aggressive panel questioners. (The final NAS report reaffirmed the basic science underlying the hockey stick reconstruction.)

Yet Mann remains keenly aware of the political import of every word. He ended his talk with an impassioned plea to action, complete with a picture of his daughter marveling at swimming polar bears at the local zoo. “I can’t imagine having to tell her when she’s grown up that the polar bears became extinct,” he said, “because we didn’t act soon enough to combat a problem that we knew was real but that we couldn’t convince the public of.”

Asked how last week’s election might change the likelihood of such action, Mann replied simply: “We have to make it clear that the ice sheets are not Republican or Democrat. They don’t have an agenda as they disappear.”