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Judith Curry On The 97% ‘Consensus’

Judith Curry, Climate Etc

With the advent of the global warming ‘pause’ in dominating the public debate on climate change,  deepening of the fog may be the objective of the  shriller perveyors of ‘the consensus.’


[T]here’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. – Dan Kahan

My, the Cook et al. 97% consensus paper is a gift to the climate blogosphere that keeps on giving.  Some insightful new posts provide fodder for additional discussion on this.

Ben Pile

Ben Pile has a new post Tom Curtis doesn’t understand the 97% paper.  Here are a few excerpts that raise some interesting points:

We see now why many environmentalists are so hostile to debate. Permitting debate — even giving the possibility of debate a moment’s thought — shatters the binary opposing categories that have been established in lieu of an actual debate of substance on climate change and what to do about it. The division of the debate into scientists versus deniers is a strategy, but one which has worn thin, as Davey’s performance on The Sunday Politics show revealed, and which Hulme alludes to.

It has been somewhat gratifying that almost all of the criticism of my post I have seen so far is from angry trolls, mostly on twitter, but one or two popped up to comment on the post. From what I can tell their argument is circular: it is irresponsible to give air/blog time to sceptics because there’s a strong scientific consensus that says they’re wrong.

Tom Curtis (who is, as far as I can tell, a partner in the Skeptical Science blog enterprise) obliges, with archetypal green invective.

There is a large measure of idiocy in Ben Pile’s post, and in Mike Hulme’s endorsement of it.

The architects of the new consensus — Cook et al and their pals — really ought to understand the dynamics of a consensus. If you begin your defence of a consensus by calling those who might belong to it ‘idiots’, the only possible outcome is that the consensus will diminish.

I certainly do know for a fact that some people’s estimates of climate sensitivity are so low as to at least imply, contrary to the IPCC statement, natural variability might account for more than 50% of the warming in the second half of the C20th. My argument, however, was that the Consensus Project is too clumsy to capture such a position.

It’s all about endorsing with these guys, isn’t it… Endorsement and rejection. Hulme should have rejected Pile and endorsed Cook et al, because Pile rejects the consensus, whereas Cook et al endorse it, as do most climate scientists. They want agreements and disagreements to be black and white, yes and no, true and false, science and denier.

But as I explain in the post, in the case of Davey, the science is being ignored by a politician, it having been displaced from the debate by the 97% figure.

JC comment:  This is an important point.  In my No consensus paper, I argue “the consensus building process employed by the IPCC does not lend intellectual substance to their conclusions. “

Moreover, as we have seen in Davey, his predecessors, and his superiors, you can say anything you like about climate change, as long as it doesn’t contradict this view of sides. You could say, for instance, that there will be 10 metres of sea level rise by 2100 and that therefore climate policies are necessary. This claim would exist far away from ‘The Science’. But it would seem to be correct according to the tests applied to it by the Consensus Project. This is disappointing, because Curtis is nearly on to something…

Further, he appears to have picked up that strange censorial attitude noteworthy also in von Storch which presumes that because they do not believe that AGW will lead to catastrophe (which is a respectable position inside the consensus), that therefore scientists who do believe that it will (also a respectable position inside the consensus) must not state that belief in public.

Surely this is a frank admission that there is no consensus on catastrophic climate change? If so, then Curtis is now in a real bind, because this deprives the ‘warmist’ crowd of their moral imperatives. Moreover, most complaints from sceptics are that the catastrophism we are all too familiar with is undue — not that there is no such thing as climate change.

Dan Kahan

Dan Kahan has chimed in with a post The distracting counterproductive 97% consensus debate drags on.   Some points that caught my eye:

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.

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.”

Unsurprisingly, the study has in the months since its publication supplied a focal target for climate skeptics, who have challenged the methods the authors employ.

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.

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.

JC comment:  In my post Climategate essay  On the credibility of climate research Part II rebuilding trust,  I wrote:  Credibility is a combination of expertise and trust.  While scientists persist in thinking that they should be trusted because of their expertise, climategate has made it clear that expertise itself is not a sufficient basis for public trust. Recent disclosures about the IPCC have brought up a host of concerns about the IPCC that had been festering in the background: involvement of IPCC scientists in explicit climate policy advocacy; tribalism that excluded skeptics; hubris of scientists with regards to a noble (Nobel) cause; alarmism; and inadequate attention to the statistics of uncertainty and the complexity of alternative interpretations. The experts do their science and ’cause’ a disservice by engaging in these behaviors.

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