Watching the latest brouhaha over science historian Naomi Oreskes' now almost three-year-old article in Science–which found an extremely strong consensus on human-caused global warming in the peer-reviewed scientific literature–something struck me.
It occurred to me the global warming “skeptics” who repeatedly attacking Oreskes' study are, in their own way, dramatically dependent upon it. They need to have this study around to criticize. If it didn't exist, they'd probably have to invent it.
What made the original Oreskes study so irresistible to “skeptics” was its quantification of the somewhat intangible concept of scientific “consensus.” Oreskes examined a sample of 928 peer reviewed articles on “global climate change,” and strikingly, didn't find a single one that explicitly challenged the view that humans are driving global warming through their emissions. 928 to 0 is a pretty staggering ratio. But for “skeptics,” it also presented an opportunity in disguise.
Once “consensus” had been defined with explicit numbers, its existence could also be numerically contested. One needed only to dispute the data, or to perform a different literature review (much easier than winning the scientific argument on the merits). And that's just what the “skeptics” tried to do. Benny Peiser and all that.
So the first unsuccessful sally against the Oreskes study, circa 2005, should hardly have seemed surprising. After all, Oreskes' Science article had come out perfectly timed–nestled comfortably in between the 2001 U.N. Intergovernmental Panel on Climate Change's Third Assessment Report (money quote: “Most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations”) and the 2007 U.N. IPCC Fourth Assessment Report (money quote: “Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations”). In late 2004/early 2005, as we awaited the IPCC's 2007 iteration, Oreskes conveniently provided an update: FYI, the consensus is alive and well.
But today we no longer need the Oreskes study to know this. We have in hand the 2007 IPCC report itself. It may have taken six years, but the scientific process finally completed the long and arduous trek from “likely” to “very likely.” The “consensus” now stands reaffirmed not by a tally of scientific papers, but rather, by a vast and diligent assessment process in which the authors of those papers got together and hammered out what they could and couldn't say with confidence. It's no slight to Oreskes' work to say that the latter is far more powerful than the former.
And yet despite the all-important 2007 update from the IPCC, attacks on Oreskes and her results continue. Schulte and Monckton and all that.
How should we think about this new development? I for one have no interest in becoming yet another chronicler of who is linked to whom and who did or didn’t replicate what study using whatever methodology. These facts, however scintillating, are immaterial to either climate science or climate policy. Moreover, I'm convinced that obsessing over them is precisely what the “skeptics”/contrarians want us to do. Indeed, that's why they're so gung-ho about refuting the Oreskes study.
It's simply impossible to dismantle the scientific consensus on climate change by targeting any single piece of evidence. That consensus rests upon multiple independent datasets and multiple independent theoretical and modeling analyses. Thus, if it's ever overturned, it will only be by multiple teams of independent researchers all hitting upon contradictory findings in different areas over a lengthy time period–thereby gradually setting in motion a paradigm shift. (In other words, it's highly unlikely to happen.)
That's the reality of the situation–but people are also “cognitive misers.” Few really grasp the robust nature of the scientific consensus on climate change as I've just described it. But even though they might not understand it, political conservatives are highly inclined to doubt it. As a result, criticisms of Oreskes spread like wildfire. They're scientifically meaningless, but they nevertheless trigger instant recognition and acceptance among those who respond so favorably to the “global warming is a liberal hoax” frame.
But this also means detailed defenses of Oreskes do little or nothing to quash criticisms. Those who take arguments about the scientific consensus seriously didn't distrust Oreskes in the first place. And for those who do distrust her, contrary “facts” don’t refute the “global warming is a hoax” frame; rather, that frame quashes the contrary facts.
And so we find ourselves in this situation: The planet keeps warming, while the “skeptics” keep coming up with arguments–like attacking Oreskes–that miss the point but fire up their base. These arguments might be totally irrelevant on a scientific level, but they continue to work politically. So here's a thought: It's important to defend Oreskes, but let's also think about how we might avoid playing, over and over again, this same silly game.
Disclosure: Naomi Oreskes wrote a favorable review of my first book, The Republican War on Science, for Science.