There are people who say that what's being called "Climategate" is no big deal -- just the sausage-making of science -- and others who say it undermines all claims about human-caused global warming and about the necessity of measures to limit greenhouse-gas emissions.
Those are people with strong, passionate views on climate change, and their reactions support the idea of Climategate as a Rorschach test, that "one's view of the issue is deeply colored by his or her incoming biases," as Stephen J. Dubner said.
But I think this will be a major issue for the rest of us, too -- and for public policy moving forward. And that's as it should be.
Last month, hackers or a whistle-blower released thousands of e-mail messages and documents from the Climatic Research Unit (CRU) of England's University of East Anglia. With the United Nations Climate Change Conference kicking off on Monday, these documents have been generating a lot of attention, particularly among climate-change skeptics who have dubbed this "Climategate."
Many global-warming-theory apologists say that the e-mail messages and documents reflect a normal, honest, and messy scientific process. RealClimate.org's first response said that the documents and exchanges were "a peek into how scientists actually interact, and the conflicts show that the community is a far cry from the monolith that is sometimes imagined."
On the other side are skeptics who say these documents and correspondence prove a conspiracy to silence dissenters who don't toe the party line of man-made climate change -- that emissions from human activities are responsible for a warming of the Earth near its surface. As the Intergovernmental Panel on Climate Change working group claimed in its 2007 "Summary for Policymakers," there is "very high confidence that the global average net effect of human activities since 1750 has been one of warming." In the lay terms of Wikipedia, the core assertion of global warming/climate change is that "most of the observed temperature increase since the middle of the 20th Century was caused by increasing concentrations of greenhouse gases resulting from human activity such as fossil-fuel-burning and deforestation."
That conclusion leads to warnings, most famously from former Vice President Al Gore, that global warming requires swift and drastic government action on a global scale to avoid catastrophe.
Climategate has given skeptics of those claims new ammunition.
"The conspiracy behind the Anthropogenic Global Warming myth ... has been suddenly, brutally, and quite deliciously exposed," wrote James Delingpole.
More specifically, Bret Stephens wrote: "Climategate ... concerns some of the world's leading climate scientists working in tandem to block freedom-of-information requests, blackball dissenting scientists, manipulate the peer-review process, and obscure, destroy, or massage inconvenient temperature data ... ."
While the above quotes have obvious agendas, they touch on important issues. Delingpole's conspiracy (articulated more clearly by Stephens) seems to be supported by selections from the released e-mail messages, such as a damning, widely cited excerpt from this message about dissenting papers: "Kevin and I will keep them out somehow -- even if we have to redefine what the peer-review literature is!" (That snippet, not incidentally, has been taken grossly out of context. The author was referring to two specific articles he believed were flawed.)
These CRU documents, in other words, can be viewed or construed as evidence for a long-held belief among some skeptics that dissent on the issue of climate change has been quashed, creating a false consensus within major scientific organizations and in peer-reviewed scientific journals.
More interesting to me is RealClimate.org's claim that the scientific community isn't a "monolith," a seeming acknowledgment that there is no actual consensus on global warming.
Of course there isn't, if one believes (as my dictionary sources do) that "consensus" requires unanimity.
And we shouldn't expect unanimity in science on emerging issues. Scientists observe and measure, and then they interpret the data. Even when the research is well-designed and the validity of the data is undisputed, there is still a decent chance that the conclusions won't be uniform.
And when one delves into predictions, even general agreement can be hard to achieve. So when looking at climate data and peering into the future, there's naturally a wide range of interpretation and projection.
Yet advocates for proposed remedies to global warming -- such as a cap-and-trade system for carbon-dioxide emissions -- stress scientific consensus as a rationale for action.
As a blanket statement, "there is scientific consensus on global warming" is provably untrue. Find a climate scientist who doesn't believe that humans cause global warming, and the asserter has lost his or her credibility.
But in a narrowly defined context, a claim of unanimity is true. In "The Scientific Consensus on Climate Change," author Naomi Oreskes analyzed scientific articles on climate change with the premise that group statements -- such as those of the Intergovernmental Panel on Climate Change and the National Academy of Sciences -- might "downplay legitimate dissenting opinions. That hypothesis was tested by analyzing 928 abstracts, published in refereed scientific journals between 1993 and 2003 ... with the keywords 'climate change.'"
She found "75 percent ... either explicitly or implicitly accepting the consensus view; 25 percent dealt with methods or paleoclimate, taking no position on current anthropogenic [resulting from human activity] climate change. Remarkably, none of the papers disagreed with the consensus position."
What Climategate has done is attack the "consensus" refrain on two fronts. First, there's the appearance of censorship of dissenting views -- the creation of an artificial consensus. Second, now even the data is in question.
As Will Wilkinson summarized: "The Climategate files strongly suggest that at least some of the science is not rock solid and that the scientific consensus is at least in part the product of silencing or marginalizing those who might upset it."
Megan McArdle added: "There is strong evidence that a small group of scientists has inappropriate power over the process of consensus-building."
Those basic, critical truths have been acknowledged by people on both sides of the issue. Stephens, an obvious skeptic, wrote: "The deeper question is why the scientists behaved this way to begin with, especially since the science behind man-made global warming is said to be firmly settled."
And George Monbiot, in a column satirizing the idea of a wide conspiracy, wrote: "There appears to be evidence here of attempts to prevent scientific data from being released, and even to destroy material that was subject to a freedom-of-information request. Worse still, some of the e-mails suggest efforts to prevent the publication of work by climate skeptics, or to keep it out of a report by the Intergovernmental Panel on Climate Change."
(He added: "Do these revelations justify the skeptics' claims that this is 'the final nail in the coffin' of global-warming theory? Not at all. They damage the credibility of three or four scientists. They raise questions about the integrity of one or perhaps two out of several hundred lines of evidence.")
So while Climategate won't change the views of hardened partisans, it could still undermine efforts to enact legislation designed to combat global warming.
There's a soft middle that believes that humans contribute significantly to global warming, and that a substantial reduction in carbon-dioxide emissions is probably wise. I would guess this is a majority of voters in this country. I count myself in this group. (I found the Al Gore lecture movie An Inconvenient Truth a bald piece of self-promoting propaganda.)
This is a group that is ambivalent about measures meant to curb carbon-dioxide emissions, that supports their goals but wavers about the approaches, the costs, and the benefits. I am certainly persuadable but not yet persuaded.
For me, the e-mail messages and documents don't prove anything, but they inject doubt about the data and methods and conclusions of climate-change science, and make me less certain about the direness of the situation. That means I'm less likely to support legislation such as cap-and-trade. And if there are enough people like me on this issue ... .
This could have been a year of major milestones for advocates of emissions controls in this country. Cap-and-trade legislation passed in the U.S. House and is supported by President Barack Obama. The upcoming U.N. conference could have focused renewed attention on the issue and created momentum, and voter mobilization could have pushed the Senate to action.
But there's a new source of doubt and skepticism, not just about a proposed solution but about the science underlying it. Climategate has put proponents of emissions reduction on the defensive, and they have a lot of damage control ahead of them.
