I don’t want to go back there but since 10's of millions of people get all their news exclusively from this blog (oh, btw, there was a royal baby, everyone, in case any of you care) I felt that I ought to note that controversy continues to attend the Cook et al. study that, “97%” of climate scientists agree that human activity is contributing to climate change.
Studies making materially identical findings have been appearing at regular intervals for the better part of a decade. Every time, they are widely heralded; indeed, the media have been saturated with claims that there is “scientific consensus” on climate change since at least 2006, when Al Gore made that message the centerpiece of a $300-million effort to build public support for policies to reduce carbon emissions in the U.S.
But it is demonstrably the case (I'm talking real-world evidence here) that the regular issuance of these studies, and the steady drum beat of “climate skeptics are ignoring scientific consensus!” that accompany them, have had no—zero, zilch—net effect on professions of public “belief” in human-caused climate change in the U.S.
On the contrary, there’s good reason to believe that the self-righteous and contemptuous tone with which the “scientific consensus” point is typically advanced (“assault on reason,” “the debate is over” etc.) deepens polarization. That's because "scientific consensus," when used as a rhetorical bludgeon, predictably excites reciprocally contemptuous and recriminatory responses by those who are being beaten about the head and neck with it.
Such a mode of discourse doesn't help the public to figure out what scientists believe. But it makes it as clear as day to them that climate change is an "us-vs.-them" cultural conflict, in which those who stray from the position that dominates in their group will be stigmatized as traitors within their communities.
This is not a condition conducive to enlightened self-government.
Nevertheless, the authors of the most recent study announced (in a press release issued by the lead author’s university) that “when people understand that scientists agree on global warming, they’re more likely support politics that take action on it,” a conclusion from which the authors inferred that “making the results of our paper widely-known is an important step toward closing the consensus gap and increasing public support for meaningful climate change.”
It’s silly to imagine that ordinary members of the public can be made familiar with results of particular studies like this.
But it’s very predictable that they will get wind of continuing controversy over “what scientists believe” so long as advocates keep engaging in impassioned, bitter, acrimonious debates about the validity of studies like this one.
That’s too bad because, again, the best evidence on why the public remains divided on climate change is the surfeit of cues that the issue is one that culturally divides people. Those cues motivate members of the public to reject any evidence of “scientific consensus” that suggests it is contrary to the position that predominates in their group. Under these circumstances, one can keep telling people that there is scientific consensus on issues of undeniable practical significance, and a substantial proportion of them just won’t believe what one is saying.
The debate over the latest “97%” paper multiplies the stock of cues that climate change is an issue that defines people as members of opposing cultural groups. It thus deepens the wellsprings of motivation that they have to engage evidence in a way that reinforces what they already believe. The recklessness that the authors displayed in fanning the flames of unreason that fuels this dynamic is what motivated me to express dismay over the new study.
But look: Matters like these are admittedly complex and open to reasonable disagreement. I could be wrong, and I welcome evidence & reasoned argument that would give me reason to revise my views. In the best spirit of scholarly conversation, the lead author of the latest "97%" study, John Cook, penned a very perceptive, engaging, and gracious response--and I urge people to take a look at it & decide for themselves if my reaction was well-founded.
So what’s the new development?
Mike Hulme, a climate scientist who is famous for his own conjectures about public conflict over climate change has apparently added his voice to the chorus of critics.
I say apparently because the comments attributed to Hulme appear in a short on-line comment on a blog post that described an interview of the UK Secretary of State for Energy and Climate Change. I assume Hulme must be the actual author of the comment because no one seems to be challenging that and he hasn’t disavowed it.
Anyway, in the comment, Hulme (assuming its him!) acidly states:
Needless to say, the comment—because it comes from a figure of significant stature among proponents of aggressive policy engagement with the risks posed by climate change—has lifted the frenzy surrounding the latest “97%” study to new heights (most noticeably in dueling twitter posts, a form of exchange more suited for playground-style taunting than serious discussion).
What to say?
First, what a sad spectacle. Honestly, it’s hard for me to conceive of an issue that could be further removed from the important questions here—ones involving what the best empirical evidence reveals about climate change and about the pathologies that make public debate impervious to the same—than whether the latest “97%” study is “sound.”
Second, I think Hulme’s frustration, while probably well-founded, is not as well articulated as it should be. What exactly does he mean, e.g., when he says “public understanding of the climate issue has moved on”? The statement admits of myriad interpretations, many of which would be clearly false (such as that polarization in the U.S., e.g., has abated).
Of course, it's not reasonable to expect perfect clarity or cogency in 5-sentence blog comment. Hulme has written a very thoughtful essay in which he presents an admirably clear and engaging case against trying to buy public consensus in the currency of appeals to the authority of "scientific consensus." His argument is founded on the manifestly true point that science's way of knowing consists neither in nose counting nor appeals to authority--and to proceed as if that weren't so demeans science and makes the source of the argument look like a fool.
My position is slightly different from his, I think.
I'd say it makes perfect sense for the public to try to give weight to what they perceive to be the dominant view on decision-relevant science. Indeed, it's a a form of charming but silly romanticism to think that ordinary members of the public should "take no one's word for it" (nullius in verba) but rather try to figure out for themselves who is right when there are (as is inevitably so) debates over decision-relevant science.
Members of the public are not experts on scientific matters. Rather they are experts in figuring out who the experts are, and in discerning what the practical importance of expert opinion is for the decisions they have to make as individuals and citizens.
Ordinary citizens are amazingly good at this. Their use of this ability, moreover, is not a substitute for rational thought; it is an exercise rational thought of the most impressive sort.
But in a science communication environment polluted with toxic partisan meanings, the faculties they use to discern what most scientists believe are impaired.
The problem with the suggestion of the authors' of the latest "97%" study that the key is to "mak[e] the results of [their] paper widely-known" is that it diverts serious, well-intentioned people from efforts to clear the air of the toxic meanings that impede the processes that usually result in public convergence on the best available (and of course always revisable!) scientific conclusions about people can protect themselves from serious risks.
Indeed, as I indicated, the particular manner in which the "scientific consensus" trope is used by partisan advocates tends only to deepen the toxic fog of cultural conflict that makes it impossible for ordinary citizens to figure out what the best scientific evidence is.
Meanwhile, time is “running out.” On what? Maybe on the opportunity to engage in constructive policies on climate change.
But more immediately, time is running out on the opportunity to formulate a set of genuinely evidence-based strategies for promoting constructive engagement with the IPC’s 5th Assessment, which will be issued in installments beginning this fall. It will offer an authoritative statement of best current evidence on climate change.
Much of what it has to say, moreover, will consist in important revisions and reformulations of conclusions contained in the 4th Assessment.
That’s inevitable; it is in the nature of science for all conclusions to be provisional, and subject to revision with new evidence.
In the case of climate change, moreover, revised assessments and forecasts can be expected to occur with a high degree of frequency because the science involved consists in iterative modeling of complex, dynamic systems—a strategy for advancing knowledge that (as I’ve discussed before) self-consciously contemplates calibration through a process of prediction & error-correction carried out over time.
My perspective is limited, of course. But from what I see, it is becoming clearer and clearer that those who have dedicated themselves to promoting public engagement with the best available scientific evidence on climate change are not dealing with the admittedly sensitive and challenging task of explaining why it is normal, in this sort of process, to encounter discrepancies between forecasting models and subsequent observations and to adjust the models based on them. And why such adjustment in the context of climate change is causefor concluding neither that “the science was flawed” nor that “there is in fact nothing for anyone to be concerned about.”
Part of the evidence, to me, that they aren’t preparing to do this is how much time they are wasting instead debating irrelevant things like whether “97%” of scientists believe a particular thing.
p.s. Please don’t waste your & readers’ time by posting comments saying (a) that I am arguing there isn’t scientific consensus on issues of practical significance on climate change (I believe there is); (b) that I think it is “unimportant” for the public to know that (it’s critical that that it be able to discern this); or (c) that I am offering up no “alternative” to continuing to rely on a strategy that I say doesn’t work (not true; but if it were-- then what? I should nod approvingly if you propose that we all resort to prayer, too?). Not only are none of these things either stated or implied in what I’ve written. They are mistakes that I’ve corrected multiple times (e.g., here, here, here . . .).
With the help of net-saavy commentators, I was able to flush out a comment in which Hulme did indeed elaborate on his initial one:
Interesting & edifying. Actually, I think readers would be well-served, as another commenter on my post pointed out, to read the blog Hulme himself was commenting on.
Anyway, here Hulme emphasizes that "97% consensus" doesn't uniquely determine policy responses -- clearly true.
But I still don't know what he meant when he said public debate has "moved on" from the issue of scientific consensus. If he meant by that that at this point the public "agrees" on the fundamentals about climate science -- including that human CO2 emissions cause climate change -- he is wrong, at least as applied to the U.S. (I definitely find the suggestion of Steve Bloom that Republicans are suffering b/c of their positionon any issues related to climate change to be ungrounded in anything remotely like real world evidence.)
If we can't get "up to" and "past" that point, we can't "move on" to policy debates that relate to what "what to do given the evidence"-- since there will certainly be a variety of options that make sense depending on how diverse public values are brought to bear on the relevant tradeoffs they entail. That's what democracy is all about.
If they are truly at that point in the UK, they are very lucky indeed. Based on my many conversations w/ researchers and science communicators from the UK, I doubt that's really the case.
Anyway, from a US perspective, I think Cook et al. are definitely right to be interested in trying to improve public understanding of what the state of the scientific evidence is -- including the fundamental point that "human CO2 emissions increase global temperatures" as well as all the points on which there are uncertainties about what the consequences of that are and what sorts of responses make sense in light of them.
I just disagree that the way to promote such comprehension, in the U.S. at least, is to publicize Cook et. al's own study, particularly in the way that they and other climate-change policy advocates have been. The focus has to be on dispelling the toxic meanings that pervade the science communicatoin enviornment & prevent diverse members of the public from forming a practical understanding of the beest available evidence.
Bottom line, though, is that Hulme was frustrated-- as I am -- that the "97% consensus" message is being substituted for forms of communication that in content & style promote constructive public engagement rather than deflect it.
I think this was quite foreseeable, and thus all the more regrettable.