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« Weekend update: Science of Science Communication 2.0: on CRED "how to" manual & more on 97% messaging | Main | Doh! »
Wednesday
Feb252015

"the strongest evidence to date" on effect of "97% consensus" messaging

There's a new study out on effect of "97% consensus" messaging.

Actually, it is a new analysis of data that were featured in an article published a few months ago in Climatic Change.

The earlier paper reported that after being told that 97% of scientists accept human-caused climate change, study subjects increased their estimate of the percentage of scientists who accept human-caused climate change.

The new paper reports results, not included in the earlier paper, on the effect of the study's "97% consensus msg" on subjects' acceptance of climate change, their climate change risk perceptions, and their support for responsive policy measures.

The design of the study was admirably simple: 

  1. Ask subjects to characterize on a 0-100 scale their "belief certainty" that climate change is occurring, that it is caused by humans, that it is something to worry about, and that something should be done about it;
  2. tell the subjects that “97% of climate scientists have concluded that human-caused climate change is happening”; and
  3. ask the subjects to characterize again their "belief certainty" that climate change is occurring, that it is caused by humans, that it is something to worry about, and that something should be done about it.

Administered to a group of 1,104 members of the US population, the experiment produced these results on the indicated attitudes:

So what does this signify?

According to the authors, 

Using pre and post measures from a national message test experiment, we found that all stated hypotheses were confirmed; increasing public perceptions of the scientific consensus causes a significant increase in the belief that climate change is (a) happening, (b) human-caused and (c) a worrisome problem. In turn, changes in these key beliefs lead to increased support for public action.

I gotta say, I just don't see any evidence in these results that the "97% consensus msg" meaningfully affected any of the outcome variables that the authors' new writeup focuses on (belief in climate change, perceived risk, support for policy).

It's hard to know exactly what to make of  the 0-100 "belief certainty" measures. They obviously aren't as easy to interpret as items that ask whether the respondent believes in human-caused climate change, supports a carbon tax etc.

In fact, a reader could understandably mistake the "belief certainty" levels in the table as %'s of subjects who agreed with one or another concrete proposition. To find an explanation of what the "0-100" values are actually measurements of, one has to read the Climatic Change paper-- or actually, the on-line supplementary information for the Climatic Change paper.

Weirdly, the authors simply don't report how the information affected the proportion of subjects who said they believe in climate change, human-caused or otherwise! If the authors have data on %s who believed in climate change before & after etc, I'm sure readers would actually be more interested in those....

But based on the "belief certainty" values in the table, it looks to me like the members of this particular sample, were, on average, somewhere between ambivalent and moderately certain about these propositions before they got the "97% consensus msg."

After, they got the message, I'd say they were, on average,  ... somewhere between ambivalent and moderately certain about these propositions.

From "75.19" to "76.88" in "belief certainty": yes, that's "increased support for policy action," but it sure doesn't look like anything that would justify continuing to spend milions & millions of dollars on a social marketing campaign that has been more or less continuously in gear for over a decade with nothing but the partisan branding of climate science to show for it.

The authors repeatedly stress that the results are "statistically significant."

But that's definitely not a thing significant enough to warrant stressing.

Knowing that the difference between something and zero is "statistically significant" doesn't tell you whether what's being measured is of any practical consequence.  

Indeed, w/ N = 1,104, even quantities that differ from zero by only a very small amount will be "statistically significant."

The question is, What can we infer from the results, practically speaking? 

A collection of regression coefficients in a path diagram can't help anyone figure that out.

Maybe there's more to say about the practical magnitude of the effects, but unfortunately the researchers don't say it.

For sure they don't say anything that would enable a reader to assess whether the "97% message" had a meaningful impact on political polarization.

They say this: 

While the model “controls” for the effect of political party, we also explicitly tested an alternative model specification that included an interaction-effect between the consensus-treatments and political party identification. Because the interaction term did not significantly improve model fit (nor change the significance of the coefficients), it was not represented in the final model (to preserve parsimony). Yet, it is important to note that the interaction itself was positive and significant (β = 3.25, SE = 0.88, t = 3.68, p < 0.001); suggesting that compared to Democrats, Republican subjects responded particularly well to the scientific consensus message.

This is perplexing....

If adding an interaction term didn't "significantly improve model fit," that implies the incremental explanatory power of treating the "97% msg" as different for Rs and Ds was not significantly different from zero. So one should view the effect as the same.

Yet the authors then say that the "interaction itself was positive and significant" and that therefore Rs should be seen as "respond[ing] particularly well" relative to Ds. By the time they get to the conclusion of the paper, the authors state that "the consensus message had a larger influence on Republican respondents," although on what --their support for policy action? belief in climate change? their perception of % of scientists who believe in climate change? -- is not specified....

Again, though, the question isn't whether the authors found a correlation the size of which was "significantly different" from zero.

It's whether the results of the experiment generated a practically meaningful result.

Once more the answer is, "Impossible to say but almost surely not."

I'll assume the Rs and Ds in the study were highly polarized "before" they got the "97% consensus msg" (if not, then the sample was definitely not a valid one for trying to model science communication dynamics in the general population). 

But because the authors don't report what the before-and-after-msg "belief certainty" means were for Rs and Ds, there's simply no way to know whether the "97% consensus msg's" "larger" impact on Rs meaningfully reduced polarization.

All we can say is that whatever it was on, the "larger" impact the msg had on Rs must still have been pretty darn small, given how remarkably unimpressive the changes were in the climate-change beliefs, risk perceptions, and policy attitudes for the sample as a whole.

Sigh....

The authors state that their "findings provide the strongest evidence to date that public understanding of the scientific consensus is consequential." 

If this is the strongest case that can be made for "97% consensus messaging," there should no longer be any doubt in the minds of practical people--ones making decisions about how to actually do constructive things in the real world-- that it's time to try something else.

To be against "97% consensus messaging" is not to be against promoting public engagement with scientific consensus on climate change.

It's to be against wasting time & money & hope on failed social marketing campaigns that are wholly disconnected from the best evidence we have on the sources of public conflict on this issue.

 

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Reader Comments (40)

What I find interesting is that although the increases in the first 4 metrics was significant, the change in support for public action was not. There may be any number of reasons for this, but it seems likely that it probably boils down to either a belief that the matter is not pressing, a belief that support for public action would mean that they would then be obligated to do something about it (which in turn, they would reason, means either extra effort or a subtraction of effort from other areas they are concerned with) or a belief that nothing can be done.

February 26, 2015 | Unregistered CommenterBrian

Well shredded Dan.

I would add that with any priming experiment, whether it be having people listen to Metallica and compare before and after survey results about violent tendencies, or having people listen to some statistics on scientific consensus and compare before and after survey results on climate policy opinion, you always, always have 2 really big problems:

1.

OK you successfully primed the test takers to change their answer to survey questions immediately after the test was administered. But why do you conclude that will have any affect an hour, a day, a week or months from now? Even if listening to Ride the Lightning actually would make a person more likely to punch someone in the face 5 minutes after The Call of Ktulu ends, whether they'd still be inclined to punch someone in the face a year later is a completely separate issue.

2.

While this study showed very small effects from priming people with the 97% message, it's actually perhaps worse for the underlying theory if they show a large effect. So suppose you take 25 psych undergrads and have them take a survey, talk about the weather, then take a survey. You get another 25 undergrads to take a survey, play an hour of Grand Theft Auto, then take a survey. Low and behold the second group's survey answers indicate they now feel much more likely to punch a guy in the face.

So we then conclude that playing video games makes people violent? These are psych undergrads, they've all played *a lot* of video games in their life. So we have one group of 25 who have played on average 5000 hours of video games. And the other has played 5001 hours on average. Was it really that last hour which tipped the scales and caused them to become significantly more violent?

The 97% statistic has been really, really widely cited and publicized. I have a very hard time believing the experiment in question above was the first time the test takers had heard about it.

February 26, 2015 | Unregistered CommenterRyan

About to read the article (so note that the following post is relevant only in the broadest sense of the matter) and had a random thought this morning....

I was watching Bill Maher a few weeks back and a guest on his show (Bret Stephens) had equated the small percent of dissenting experts (on climate change) with Galileo.

Here's the quote:
No, what I think we know that what we’ve ought to have known for a very long time is that consensus should not rule science. This is not a democracy, it’s not a vote. And by the way it’s not simply…No, look, we think of great scientific discovery as proceeding from people who are willing to break with the consensus. Okay? And that is why we honor people like Galileo who broke with a certain kind of scientific consensus.

see clip here (quote is around 4:45): https://www.youtube.com/watch?v=4i--Uq8VXas

Maybe it would be prudent to discuss expert consensus in a way that doesn't focus on the experts themselves, but instead talks about the experiments and/or studies...so maybe framing scientific consensus as a majority of empirical research studies find would be less likely to trigger motivated cognition--recognizing that the public could still be influenced by the topic itself.

February 26, 2015 | Unregistered CommenterAsheley Landrum

@Brian: I think change in "support for policy" is significant. The diff in 0-100 "belief certainty" measure is 1.7 & SE is 0.4. The 0.95 CI given that SE is approximately 0.8-- so there is 0.95 chance "true" mean is between 0.9 and 1.25.

But if someone thinks that sort of trivial change in an obscure mesure gives us reason to think that walking up to someone & saying "97% of scientits believe in AGW" will have an impact on the state of polarized debate in US, they are engaged in self-delusion.

February 26, 2015 | Registered CommenterDan Kahan

@Ryan:

Agree that "demand effect" issues are huge here. If you tell someone what answer you want, they'll likely give it to you.

That's why they get (modest) change in pct of scientists estimate.

Everything else is just trivial.

(And weird: why not give us the data on how many peopole actually changed their mind on climate change or policy instead of measure of intensity of positoinj?)

February 26, 2015 | Registered CommenterDan Kahan

@Ashley:

My own sense is that for sure people do and should treat scientific consensus as guide for decisions.

But the only reason it makes sense to do that is b/c indeed science itself doesn't treat consensus as normative. In science, propositions are worthy of being believed only b/c they are open to permanent challenge. If we thought that in some area of science scientists were starting to defer to "consensus," then consensus in that area of science would no longer be a reliable guide for the rest of us.

Actually, on climate change, no segment of public "rejects" climate science consensus; they assume view of their group is consisent with it -- likely b/c of biased processing of information (selectively crediiting & discreding info on that in patterns that refinforce view that sci conensus is consisnent w/ their group's position).

I don't think it would help much to emphasiz nature of evidence -- for *most people.* Most people have no idea is what evidence is for postions known to science that they wisely accept. They figure that out by using their capacity to figure out who knows what about what.

February 26, 2015 | Registered CommenterDan Kahan

@Dan,

Whatever the reason is, we can be certain it was not "basically no one actually changed their mind." Not even the slightest possibility that's the case.

@Ashley

Less Wrong had a fascinating discussion on Galileo recently:

http://lesswrong.com/lw/lq6/the_galileo_affair_who_was_on_the_side_of/

A very interesting point possibly relevant to the climate debate is that Galileo sort of poisoned his own waters with stupid arguments. The example given was that he said the tides were evidence the Earth was in motion, because if it was still then water wouldn't be sloshing about. It let his opponents portray him as some idiot who didn't know the tides were caused by the moon, and made writing off his actually sound arguments easier.

So consider this old article that gets linked to a lot in skeptic circles:

Snowfalls are now just a thing of the past

http://www.independent.co.uk/environment/snowfalls-are-now-just-a-thing-of-the-past-724017.html

'According to Dr David Viner, a senior research scientist at the climatic research unit (CRU) of the University of East Anglia,within a few years winter snowfall will become "a very rare and exciting event".

"Children just aren't going to know what snow is," he said.'

If someone wakes up in the morning and really, really doesn't want to believe the consensus about climate change, the existence of pretty stupid statements like the above is probably all they need to get there.

February 26, 2015 | Unregistered CommenterRyan

Ryan, picking up on your point 1, there is a paper by Hobson & Niemeyer, "What skeptics believe", that primed people to give the "correct" answer and then checked back later and found most of them reverted. "However, migrations are rarely sustained..." the abstract says. It's a small sample though.

February 26, 2015 | Unregistered CommenterPaul Matthews

I'd like to see "before" and "after" histograms here. I think that would be more informative than a coefficient on the Republican-treatment interaction. (Yes, the shift in mean sets a very low upper limit on how helpful this sort of messaging is, but to get the most out of the study, we might as well see whether the shift happened at the low end or the high end or both.)

February 26, 2015 | Unregistered CommenterMW

@Mw

Wouldn't you just like to see % of subjects who said they accepted human-caused climate change before or after? and party breakdowns?

for sure, we could learn more about what effect the experrimetnal treatment had on the measures reported (besides that it apparently didn't change the average "belief certainty" level for the sample as a whole by more than a tiny amount). But the measures themselves have no meaningful reference to anything in the world.

They are also wholly unexplained in the paper. No one who reads this paper will actually know what the measures said. They won't know either from looking at the Climatic Change article, which is treated as the "supplementary information" for this one.

They'll have to dig out the on-line supplement to the climate change paper to find this:

Belief in Climate Change

Subjects were asked the following question; “How strongly do you believe that climate change is or is not happening?” Response options were given on a continuum, ranging from 0 (I strongly believe that climate change is not happening), 50 (I am unsure whether or not climate change is happening) to 100 (I strongly believe climate change IS happening).

What is that measuring?

Also, this paper states that belief in human-caused climate chnage was increased. But here's the item:

Belief in human causation

Subjects were asked the following question; “Assuming climate change IS happening: How much of it do you believe is caused by human activities, natural changes in the environment, or some combination of both?” Response options were given on a continuum, ranging from 0 (I believe that climate change is caused entirely by natural changes in the environment), 50 (I believe that climate change is caused equally by natural changes and human activities) to 100 (I believe that climate change is caused entirely by human activities).

So in fact, that 0-100 item doesn't measure "belief certainty" in human-caused global warming. It instructs the subjects to assume human-caused global warming is happening...

Do you think readers of this paper would get that impression?

February 26, 2015 | Registered CommenterDan Kahan

"tell the subjects that “97% of climate scientists have concluded that human-caused climate change is happening”"

Actually it's about 88%. See the third column of figure 1 in Doran and Zimmerman.

But who cares about truth and accuracy?

"walking up to someone & saying "97% of scientits believe in AGW""

Freudian slip, there? ;-)

I think you mean 82%. (From D&Z.)

What would be interesting would be to measure the survey participants subsequent response on being shown the source of the statistic, revealing that it was a deliberate untruth on the part of the experimenters. Would they just go back to where they were, or would they overshoot? Would that be a good way to measure the (lack of) effect of sceptics on public debate?

"Do you think readers of this paper would get that impression?"

No. But that's normal behaviour in climate change PR. It's a good way for people to justify their own jobs.

February 26, 2015 | Unregistered CommenterNiV

@Niv:

I'm simply quoting the paper on in the place where you think I made a Freudian slip. That's what they told the subjects, so that's what we should assess the impact of....

February 26, 2015 | Registered CommenterDan Kahan

I would be curious about pre- and post-analysis of participants' assessment of the prevalence of shared view among climate scientists. Is there evidence about the degree to which exposing people to information about the consensus influenced participants' estimate of that prevalence? How many folks changed their estimate of the "consensus," who were they, and how much did their views change?

It is interesting to speculate about why the "consensus gap" exists among libz (the gap between the likely prevalence of shared view among climate scientists and the perceived prevalence of that shared view among libz). There is a certain common-sense logic that providing libz with information about the "consensus" would close that gap. But I kind of doubt that there are many libz out there that haven't already heard the consensus messaging, and so I wonder why so many of them seem to underestimate the reality of the consensus - presuming that most of them get most of their info from "liberal" media. Is it just that the influence of liberal media is balanced out by hearing the messaging from conservative media - even if liberals are inclined to distrust conservative media?

Aside for the statistical issues, I have a problem with these studies because people use them to generalize from the experimental conditions to the "real world." As near as I can tell, none of these studies take into account the "real-world" factors that mediate the views of libz and conz about the consensus. Finding an effect in experimental conditions is not a particularly good basis for believing that the effect will generalize to a highly politicized context.

And then there is the problem of trying to infer longitudinal outcomes from cross-sectional data - as Ryan alludes to.

As much as I think that we can't judge the effectiveness of "consensus" messaging by noting the % of Americans who don't "believe" that ACO2 has/will be likely to significantly influence the climate (because we can't disaggregate the real-world effect of consensus messaging from the real-world effect of anti-consensus messaging), I think that using these studies to "prove" that consensus-messaging works is just an exercise in confirmation bias.

Sometimes, there's just shit that you don't know.

February 26, 2015 | Unregistered CommenterJoshua

@Joshua:

that's reported in the table & in the Climatic change paper. On avg, the estimate went up from 67% to 79% of scientists.

February 26, 2015 | Registered CommenterDan Kahan

Thanks Dan -

Maybe more of an effect than I would have guessed.

But then I wonder what the impact would have been if, as occurs in the "real world," study's participants were exposed to anti-consensus messaging as well as consensus messaging

Still, as much as people mike like to do so, you just can't control the kind of messaging people get in the real world like you can in an experiment -although you certainly can whine about, and claim victimization at the hands of, messaging from the other "side" -- as we see in practically every thread throughout the climatechange-o-sphere.

The media make a very convenient scapegoat.

February 26, 2015 | Unregistered CommenterJoshua

@Joshua:

I agree. That's the external validity quesiton.

But this element of the study-- impact on beliefs, risk perceptions, policy attitudes-- is not even internally valid: it does not do what the authors say it does.

February 26, 2015 | Registered CommenterDan Kahan

PaulM

However, migrations are rarely sustained..." the abstract says. It's a small sample though.

It may be a small sample. But I'd bet several quatloos this one is the right answer.

Until someone shows strong evidence that a changed view IS sustained by some very brief presentation sandwiched between two survey questions, I'd tend to believe people whose answered changed on a survey revert back.

February 26, 2015 | Unregistered Commenterlucia

If the 97% message is a gateway, judging by the size of the effects the gate must be the size of a mouse.

Additional evidence that people's attitudes drift back over time is in a study by Harper & Philo (6 months after an intervention, people's concern had returned pretty much to baseline) and by Rachel Howell's study of the long-term behavioural effect of Age of Stupid, a UK documentary (2 years later - little effect). I also remember seeing it in an Australian study after a 2 day workshop (forgotten author or title).

I can't remember seeing a climate change study that shows a short intervention having a substantial long-term effect on behaviour (some attitudes, yes, but behaviour, no). I have seen such effects in other areas like educational achievement, but not CC communication. An interesting case of Dan's "measurement problem" to compare when it does and does not work.

February 26, 2015 | Unregistered CommenterKris

DK,

I agree with you on all fronts! I was trying to think of something they could do now (in a blog post or whatever) that would make their results more informative. But yes, clarifying what they measured (or at least how they measured it) is more important, and it's not ok that it's ambiguous in the paper itself.

February 26, 2015 | Unregistered CommenterMW

Asheley,

I also saw the episode of Real Time you referenced wherein Mr Stephens attempted to make the argument that people who deny climate change should be taken more seriously because Galileo also went against the "consensus" on geocentrism. Of course, that is a terribly weak argument for reasons I'm sure I don't have to mention here.

I've actually coined the term for people who take that type of stance on any number of issues the "Galileo Effect". I truly believe it makes people feel smart, superior or "well positioned" to compare themselves with Galileo in this way, because there is usually few other ways they could do so.

The difference, of course, is that Galileo went against a dogmatic consensus using scientific data, whereas those predisposed with the Galileo Effect are going against scientific consensus usually using some form or another of dogma.

February 26, 2015 | Unregistered CommenterBrian

"I'm simply quoting the paper on in the place where you think I made a Freudian slip. That's what they told the subjects, so that's what we should assess the impact of...."


The 'Freudian' was a reference to your typo. Weak attempt at humour, there.

But no, I don't think it's what they told their subjects. There are material differences between the opinions of "scientists", "climate scientists", and "climate scientists who can get a lot of papers published in the (generally very much pro-global warming) climate science journals". It's important to be clear which one of these you're talking about.

My point was that they're wrong about the amount of dissent in the group they identified by a factor of four; for the group you identified it's a factor of six. There are some people who would say that's "close enough for social sciences", but I'm sure you can do better. You're quite right that they measured the effect on their subjects of a particular lie, and so that's what we should be talking about. My point was that the story doesn't end there. After being told by the climate campaigners that "97% of climate scientists agree", sceptics will come along and point out that that's wrong, and be able to prove it with citations to peer-reviewed surveys. Don't you think that being caught out lying will have a net counter-productive effect regarding "the message"? Or do you think that the sceptics will be similarly ineffective at changing anybody's minds? I could go with either.

There are ethical questions and rules over when it is OK to deceive test subjects in psychological experiments. I'd be interested to know if they were followed.

But in any case I agree that the change is likely to be fragile. People who are that easily persuaded by arguments from authority can surely be persuaded just as easily in the opposite direction. We just require an equal and opposite authority.

"The difference, of course, is that Galileo went against a dogmatic consensus using scientific data, whereas those predisposed with the Galileo Effect are going against scientific consensus usually using some form or another of dogma."

We use scientific data. Most of the people arguing for the consensus don't. They don't understand the physics, or know what the scientific evidence actually *is*. They've not looked at the data. All they know is that "97% of scientists say so". 'Consensus' is dogma.

February 26, 2015 | Unregistered CommenterNiV

@NiV

You would be right if I were addressing "they". My point was that scientists' opinions are a result of scientific understanding. It may have been a slight tangent from the topic posted by Dr Kahan, but it was tangent I was following from what another person wrote.

Also, no one is a specialist in everything. We live life by consensus measurement. It's the root of the consensus that is important (ie scientific vs dogmatic).

February 26, 2015 | Unregistered CommenterBrian

@NiV

What would you think of the hypothesis that X for X, on balance making a stupid argument in support of a position is more damaging than making a good argument in favor is helpful to it?

February 26, 2015 | Unregistered CommenterRyan

I am always amused at how people like Brian miss a big point:

I've actually coined the term for people who take that type of stance on any number of issues the "Galileo Effect". I truly believe it makes people feel smart, superior or "well positioned" to compare themselves with Galileo in this way, because there is usually few other ways they could do so.

The difference, of course, is that Galileo went against a dogmatic consensus using scientific data, whereas those predisposed with the Galileo Effect are going against scientific consensus usually using some form or another of dogma.

Galileo did not go "against a dogmatic consensus using scientific data." Galileo had no evidence his position was correct. There was at least one other popular theory which fit the available evidence as well as Galileo's did. Galileo refused to accept that, claiming his position was correct when he couldn't prove it.

There wasn't even a dogmatic opposition to his position. The Catholic church was largely supportive of Galileo. The only reason they started having a problem with him was he was promoting his position as fact when he didn't have the evidence to back it up. Of course the Church told him that was unacceptable.

But there was no dogmatic opposition from the Church. They didn't tell Galileo he couldn't promote his theories. They didn't even tell Galileo he couldn't teach his theories as fact. All they told Galileo was if he wanted to teach his theories as fact, he needed to provide evidence to prove them.

That's exactly how science should work. Scientists shouldn't state things as fact if they don't have the to support their claims. Galileo's ego was just too big to act like a scientist should, resulting in him balking at the simple demand of, "Prove what you claim is true."

And as though that wasn't bad enough, Galileo insisted on his theories, which he couldn't prove, meant the Church was wrong in how it interpreted the Bible. He insisted his unproven theories meant he got to redefine Scripture. It was only after Galileo challenged the Church on biblical interpretations based upon his unproven work (and publicly insulted the Pope) the Church told him he needed to prove his work if he wanted to state it as fact.

The reality is the Catholic church behaved well during the Galileo affair. It was more on the side of science than Galileo was. Once you realize that, it becomes very funny to see people using the Galileo metaphor. Under that metaphor, if the IPCC (or climate science in general) were the Catholic churce, the IPCC would be fair-minded, tolerant and determined to base its beliefs on what the evidence shows.

If skeptics are Galileo, that'd mean they are rude and arrogant, demanding people believe things skeptics have no proof for and insulting anyone who doesn't cater to their egos.

That seems far more damning than responses like Brian's, especially when responses like his are built upon misrepresenting what actually happened.

February 27, 2015 | Unregistered CommenterBrandon Shollenberger

Upthread, Ryan said:

@Dan,

Whatever the reason is, we can be certain it was not "basically no one actually changed their mind." Not even the slightest possibility that's the case.

I'm not sure if that quote is something anyone has actually said, but it is similar to what I said in my post about this paper. As such, I feel I need to state my disagreement.

This paper provides absolutely no evidence anyone changed their mind about anything. There are many psychological reasons people may give different answers to the same question at different times even though their underlying beliefs have not changed. Simply pointing to different answers cannot demonstrate a change in beliefs. All it can do is demonstrate is a change in response pattern.

Did any of these 1,104 people believe something different the day after they participated in the study than they believed the day before? Maybe. We can't know. Nothing the authors did can tell us.

February 27, 2015 | Unregistered CommenterBrandon Shollenberger

@Brandon

Thanks for the comment about Galileo, I checked what you said and learned something new today (the reality is a bit more subtle than your description but it's a useful summary).

@Dan

Perhaps you already know this, but the Galileo affair looks like a prototypical example of "cultural worldview polarization". Doesn't look surprising therefore when people with opposing opinions today will seek to claim that they are the true heirs to the "winning" side of the argument, namely, Galileo.

I quote from a fascinating article by Owen Gingerich, a historian of astronomy (http://www.asa3.org/ASA/PSCF/2003/PSCF6-03Gingerich.pdf)


In 1674, Robert Hooke summarized the state of play of the arguments. The problem of the earth’s mobility, he wrote, “hath much exercised the Wits of our best modern Astronomers and Philosophers, amongst which notwithstanding there hath not been any one who hath found out a certain manifestation either of the one or the other Doctrine.” Thus, he suggested, people let their prejudices reign. Some "have been instructed in the Ptolemaik orTichonick System, and by the Authority of their Tutors, over-awed into a belief, if not a veneration thereof: Whence for the most part such persons will not indure to hear Arguments against it, and if they do, ‘tis only to find Answers to confute them.”

Hooke confirms what I have been arguing, namely that the best and most persuasive reason for adopting the Copernican system up through his time was the proportion and harmony of the world. He wrote: On the other side, some out of a contradicting nature to their Tutors; others, by as great a prejudice of institution; and some few others upon better reasoned grounds, from the proportion and harmony of the World, cannot but embrace the Copernican Arguments.

But Hooke allows: What way of demonstration have we that the frame and constitution of the World is so harmonious according to our notion of its harmony, as we suppose? Is there not a possibility that things may be otherwise? nay, is there not something of a probability? may not the Sun move as Ticho supposes, and that the Planets make their Revolutions about it whilst the Earth stands still, and by its magnetism attracts the Sun and so keeps him moving about it?

There is needed, Hooke declares, an experimentum crucis to decide between the Copernican and Tychonic systems, and this he proposed to do with a careful measurement of the annual stellar parallax.

February 27, 2015 | Unregistered CommenterKris

"My point was that scientists' opinions are a result of scientific understanding."

Sometimes they are, sometimes they're not. And it's often very difficult to tell the difference.

"No scientist who wishes to maintain respect in the community should ever endorse any statement unless they have examined the issue fully themselves", as Tom Wigley put it, but as he also points out a lot of them will.

"Also, no one is a specialist in everything. We live life by consensus measurement."

Which is to say, we live life by argument from authority. It's a useful heuristic, but it's not scientific.

"What would you think of the hypothesis that X for X, on balance making a stupid argument in support of a position is more damaging than making a good argument in favor is helpful to it?"

It depends on whether it is the only, or loudest voice.

I think a good argument can overrule any number of stupid ones. So if both are available, then the good argument is more helpful than the stupid ones are damaging. But if you only have one or the other, then I think it might be possible that stupid arguments stick in the mind better, and so have more influence.

It also depends on what you mean by "damaging". If a visibly stupid argument discredits a wrong idea that it is supporting, is that 'damaging'? It damages the credibility of the idea itself, but does it damage the good of society, or the general scientific understanding? Doesn't it rather help clean it up? Shouldn't we get these things out into the open, so that we can judge correctly?

Consider the following passage: "If published as is, this paper could really do some damage. It is also an ugly paper to review because it is rather mathematical, with a lot of Box-Jenkins stuff in it. It won't be easy to dismiss out of hand as the math appears to be correct theoretically..." What sort of "damage" is being talked about here? Can you "damage" science by presenting arguments with correct mathematics?

February 27, 2015 | Unregistered CommenterNiV

@NiV

So, of course, we first would invoke Yudkowsky's second virtue of rationality:

The second virtue is relinquishment. P. C. Hodgell said: “That which can be destroyed by the truth should be.” Do not flinch from experiences that might destroy your beliefs. The thought you cannot think controls you more than thoughts you speak aloud. Submit yourself to ordeals and test yourself in fire. Relinquish the emotion which rests upon a mistaken belief, and seek to feel fully that emotion which fits the facts. If the iron approaches your face, and you believe it is hot, and it is cool, the Way opposes your fear. If the iron approaches your face, and you believe it is cool, and it is hot, the Way opposes your calm. Evaluate your beliefs first and then arrive at your emotions. Let yourself say: “If the iron is hot, I desire to believe it is hot, and if it is cool, I desire to believe it is cool.” Beware lest you become attached to beliefs you may not want.

Of course Eliezer was listing virtues of rationality, not virtues of civil society. And I find commonly accepted obvious falsehoods far too common to believe they don't serve some useful purpose for human civilizations.

When Dan says always accept the scientific consensus as true, even when it is false, I think the idea is that on balance the benefits of never rejecting as false an actually true consensus outweigh the harms of sometimes accepting as true an idea which is actually false. After all, these are educated professionals we're talking about, they're far more likely to be right than wrong.

Feel free to spit those words right out your mouth Dan.

On the point itself, I have a hard time imagining how to test the hypothesis, but I am quite open to the idea that it is in fact correct.

"If published as is, this paper could really do some damage. It is also an ugly paper to review because it is rather mathematical, with a lot of Box-Jenkins stuff in it. It won't be easy to dismiss out of hand as the math appears to be correct theoretically..."

One of many "holy cow you couldn't make this shit up" blurbs from the email leak. I'll say this, if someone still believes the global warming consensus is correct, that's one thing, but if they also still believe the process by which the consensus came about was not corrupt, that would explain the iron burn on their face.

February 27, 2015 | Unregistered CommenterRyan

"And I find commonly accepted obvious falsehoods far too common to believe they don't serve some useful purpose for human civilizations."

"All models are wrong, but some are useful", as the statistician George Box said (he of "Box-Jenkins stuff").

And all human knowledge consists of models - which can only ever be uncertain approximations. Given that everything we believe is false or uncertain on some level, I try to be charitable about the sorts of things people commonly accept. Mostly I'm more relaxed about it than many other scientists. It's hard work sometimes, though.

"When Dan says always accept the scientific consensus as true, even when it is false, I think the idea is that on balance the benefits of never rejecting as false an actually true consensus outweigh the harms of sometimes accepting as true an idea which is actually false."

Argument from Authority is a useful heuristic I don't deny, especially for those without the training to do better. We all rely on heuristics - unreliable, illogical, irrational yet often useful rules of knowledge. Assuming that correlation implies causation is another one. Logical fallacies are so common because they are built in to human reasoning, precisely because they often work. If a blind man was to build a computer out of meat, it would be a truly admirable achievement to have created the human brain, and we can surely forgive a few peccadilloes.

My argument, though, is that it is not a 'scientific' method or mode of thought, and should not be claimed to be one. Science achieves greater assurance than raw, untrained human reasoning, precisely because it rejects fallacies like Argument from Authority. A fallacious, political concept like 'consensus' should not be allowed to share in science's reputation for reliability. It's not totally unreliable, but it doesn't give the levels of reliability that science is known for. It's misleading to confuse the public on this point. 'Scientific consensus' is an oxymoron; a contradiction in terms.

"After all, these are educated professionals we're talking about, they're far more likely to be right than wrong."

Mmm Hmm. That would be the Argument ad Verecundiam that Locke talked about. No, they're not more likely to be right than wrong, educated professionals are subject to the same limitations as science generally, and on most questions regarding the universe science still does not know. Climate science is still a very young science, as sciences go, and it is studying probably the most complicated and difficult physical system that humans have direct access to - a machine with more than 10^40 independently moving parts. We can't solve it. We don't even have properly working models of it. We don't know. And until we do, the speculations of experts are more likely to be wrong than right, simply because there are infinitely more ways to be wrong than right, and therefore the odds are somewhat against us.

Feynman said: Science is the belief in the ignorance of experts. He was absolutely right. You always need to ask about the evidence before you can come to any conclusions on the expertise of the experts. After all, how do you know which ones are the real experts otherwise? Ask an expert on experts to tell you? Down that path of infinite regress, madness lies.

I define an 'expert' to be a person who can tell you clearly, concisely, and convincingly what the evidence and argument for a proposition is. Having studied the matter sufficiently to draw their own conclusion, they will know the best arguments and counter-arguments, what's been thoroughly checked, what's speculation, what's controversial, which paths are dead ends and irrelevancies, and so they can condense years of research and investigation for the listener into a clear and compact argument reasoning from premises to conclusion, so that you can be convinced by the argument. A man who tells you the conclusion without the argument is not being an expert, he is being an authority, and that is a completely different beast. In many ways, its antithesis. I think it was authorities that Feynman was talking about.

It is true that those not trained in science will have great difficulty in understanding and checking the arguments directly, and even those who have rarely have the time. But there are many heuristics for judging the quality of an argument without having to follow the details. The most important one of these is checking whether it has been subjected to and survived rigorous challenge. Science progresses like evolution, by the survival of the fittest. Gazelles are fast because the lions eat the slow ones. Science works because sceptics eliminate the bad ideas. Shield science from sceptics, and it is like shielding animals from predators by putting them on remote islands without any. You get the dodo - fat, slow, stupid, and flightless. If you would judge science, look for the quality of its predators. Confidence in scientific results can only be created by the attempts to knock it down. Could we ever have developed the immense confidence we now have in the second law of thermodynamics, forbidding perpetual motion machines, without all the many attempts to break it?

And with such a heuristic, phrases like "We have 25 or so years invested in the work. Why should I make the data available to you, when your aim is to try and find something wrong with it. There is IPR to consider." and "It won't be easy to dismiss out of hand as the math appears to be correct theoretically" and “It would be odious requirement to have scientists document every line of code so outsiders could then just apply them instantly.” and “The two MMs have been after the CRU station data for years. If they ever hear there is a Freedom of Information Act now in the UK, I think I’ll delete the file rather than send to anyone.” can be seen in their proper perspective.

February 28, 2015 | Unregistered CommenterNiV

RE: statement from the paper:

increasing public perceptions of the scientific consensus causes a significant increase in the belief that climate change is ... human-caused

Dan, from the text I thought the "human-caused" result was a level of belief. Instead the question asked was one of attribution - how much warming should be attributed to man made drivers. I sure would NOT have guessed that without reading the text of the actual question.

ASIDE: Interesting that the question very similar to the widely reported consensus conclusion from the last couple of IPCC reports. The IPCC says that most of recent warming is man made -- an answer equivalent to response greater than 50 to the question asked in the study. And the pre-test mean was nearly 64.

Thus, "on average" we are already believers in man-made global warming. So the science communication problem has been solved ... on average.

As for practical impact. Imagine a 'denier' with a pre-test answer to the "human-caused" question of zero ("I don't believe that man has any impact on global warming. After hearing the 97% message our denier might allow that 4% of global warming is caused by man. 4% being the mean delta. Not a difference that one would expect to have any practical significance.

March 1, 2015 | Unregistered CommenterCortlandt Wilson

@NiV

"My argument, though, is that it is not a 'scientific' method or mode of thought, and should not be claimed to be one. Science achieves greater assurance than raw, untrained human reasoning, precisely because it rejects fallacies like Argument from Authority. A fallacious, political concept like 'consensus' should not be allowed to share in science's reputation for reliability. It's not totally unreliable, but it doesn't give the levels of reliability that science is known for. It's misleading to confuse the public on this point. 'Scientific consensus' is an oxymoron; a contradiction in terms."

My dear NiV I accuse you with great remorse of making an Argument from Morality. P. C. Hodgell said: “That which can be destroyed by the truth should be.”

P.C. Hodgell was not god and having a first and middle name commonly referred to by initials confers no equal authority.

It is precisely "science's reputation for reliability" which would justify "a fallacious, political concept like 'consensus'" being shared with it.

Accuse me of a race to the consequentialist bottom, I plead guilty as charged. But I stand with Eliezer in saying one does not choose between saving a city and killing a child, one chooses between a destroyed city and an intact city containing a dead child.

"No, they're not more likely to be right than wrong, educated professionals are subject to the same limitations as science generally, and on most questions regarding the universe science still does not know. Climate science is still a very young science, as sciences go, and it is studying probably the most complicated and difficult physical system that humans have direct access to - a machine with more than 10^40 independently moving parts. We can't solve it. We don't even have properly working models of it. We don't know. And until we do, the speculations of experts are more likely to be wrong than right, simply because there are infinitely more ways to be wrong than right, and therefore the odds are somewhat against us."

In this one particular situation, due to the nitty gritty specifics of the subject matter, "they" are, of course, likely to be completely wrong. Any man of learning should easily be able to reckon such with ease.

But religious-like devotion to scientific reason and truth is not as some matter of godliness automatically justified.

Why, exactly, is dutiful adherence to scientific reckoning more important than the consequences of heuristically accepting or not accepting academic consensus?

I accused you above of rote Argument from Morality. You might have previously defended yourself, if so feel no need to repeat yourself.

"I define an 'expert' to be a person who can tell you clearly, concisely, and convincingly what the evidence and argument for a proposition is. Having studied the matter sufficiently to draw their own conclusion, they will know the best arguments and counter-arguments, what's been thoroughly checked, what's speculation, what's controversial, which paths are dead ends and irrelevancies, and so they can condense years of research and investigation for the listener into a clear and compact argument reasoning from premises to conclusion, so that you can be convinced by the argument. A man who tells you the conclusion without the argument is not being an expert, he is being an authority, and that is a completely different beast. In many ways, its antithesis. I think it was authorities that Feynman was talking about."

And so the common man, lacking extraordinary wherewithal, is burdened with reckoning the difference between a good priest and a bad priest? Telling if some man is or is not a priest is challenge enough! If he cannot simply trust a priest, how is he to live?

"It is true that those not trained in science will have great difficulty in understanding and checking the arguments directly, and even those who have rarely have the time. But there are many heuristics for judging the quality of an argument without having to follow the details. The most important one of these is checking whether it has been subjected to and survived rigorous challenge. Science progresses like evolution, by the survival of the fittest. Gazelles are fast because the lions eat the slow ones. Science works because sceptics eliminate the bad ideas. Shield science from sceptics, and it is like shielding animals from predators by putting them on remote islands without any. You get the dodo - fat, slow, stupid, and flightless. If you would judge science, look for the quality of its predators. Confidence in scientific results can only be created by the attempts to knock it down. Could we ever have developed the immense confidence we now have in the second law of thermodynamics, forbidding perpetual motion machines, without all the many attempts to break it?"

Well I suppose you preempted my question.

So I must ask, is this a failure of the faithful, or a failure of the priesthood? Does the corruption lie within the common man who lives according to the scripture as laid down by the clergy, or does it lie with the priests who've turned against the faith?

Remember, Dan is asking the common man to have faith. He takes no position on the possible corruption of the clergy.

March 5, 2015 | Unregistered CommenterRyan

Find an interesting take on Kahan's latest geo-engineering study below. Besides the sheer impracticality of actually using a geo-engineering frame to reduce political polarization, his "depolarization" effect-sizes appear to be extremely small. Funny that he points this out in research that he was not involved in but fails to mention it when it comes to his own research....motivated reasoning?

http://www.skepticalscience.com/kahan-geoeng-polar.html

March 5, 2015 | Unregistered CommenterDavid Kent

@David:

Curious: how big were the effect sizes in "geoengineering study," in your estimation? And how big should one would expect them to be to draw an inference from them?

March 5, 2015 | Registered CommenterDan Kahan

Ryan,

"My dear NiV I accuse you with great remorse of making an Argument from Morality. P. C. Hodgell said: “That which can be destroyed by the truth should be.”"

I quite agree with P.C. Hodgell, and not just because of his initials. His statement, like mine, is certainly a moral argument. But is it an argument from morality? I assume you mean arguing "Is" from "Ought".

Let's see. In the 'Is' category we have that Argument from Authority is not a scientific mode of thought, science is more reliable because it rejects fallacies, AfA is not totally unreliable, but less reliable than science, and it's misleading to confuse the public about whether AfA gives the assurance of science. 'Scientific consensus' is an oxymoron.

In the "Ought" category we have that AfA should not be claimed to be a scientific mode of thought, and should not be allowed to share science's reputation for reliability.

To complete the moral argument, we have to add the moral rule that it's wrong to make claim that are not true (with a variety of exceptions in circumstances that I suggest don't apply here so I'm not going to try to delineate). Interestingly, that's pretty much the same as P.C. Hodgell's rule.

Which of the "Is" statements do you think is derived from an "Ought" statement?

"It is precisely "science's reputation for reliability" which would justify "a fallacious, political concept like 'consensus'" being shared with it."

No, I don't think so. But there may be a legitimate confusion here, because the word "science" is sometimes alternately used to describe either the method or the collected conclusions developed using it. (Or sometimes the human institution of scientists, but I think that's excluded by context here.) A lot of people define 'science' as "what scientists say". However, I'm not using it in that sense, although I admit I didn't clearly say so.

The sort of statements that should share in science's reputation are clear and precise arguments from evidence that have been thoroughly challenged and checked. This is NOT the same as "Things scientists say". The argument behind it is that if a lot of scientists say it, and they've been doing their jobs, then it's probably been challenged and checked by all of them. But this argument rests on an unfounded assumption. 'Scientists' (meaning the profession, as opposed to users of the scientific method) do not always challenge and check statements before endorsing them. As Dan has argued here on previous occasions, scientists use AfA and 'consensus' too.

If it can be shown that scientists have indeed challenged and checked a result, then consensus may be interesting, but if so, the reliability we can justifiy rests on the evidence of the checks, not the scientists opinions. Opinions without such evidence are hearsay, and opinions with positive evidence that they have not been checked undermine even the unreliable heuristic.

"But I stand with Eliezer in saying one does not choose between saving a city and killing a child, one chooses between a destroyed city and an intact city containing a dead child."

Would that be one of those Aztec cities that practices child sacrifice?

"But religious-like devotion to scientific reason and truth is not as some matter of godliness automatically justified."

It's not automatically true, but the justification for it is that it's the best we've got, and the best we can do.

"Why, exactly, is dutiful adherence to scientific reckoning more important than the consequences of heuristically accepting or not accepting academic consensus?"

It's not. I'm not arguing that people should only and always use science to make decisions. I'm arguing that people should not use fundamentally non-scientific methods and call that science.

So long as you openly agree that they're unreliable unscientific heuristics, you can use AfA and ad populam and all the other fallacies as much as you like. You can believe it because academics said so. You can believe it because a government spokesman said so. You can believe it on the word of high priests and bishops. You can believe stuff because the fairies told you in a dream, or because Venus is in conjunction with Uranus in the constellation of Virgo. What you can't legitimately do is call it science, because it's not.

I'm not arguing about what people are allowed to believe, or what methods they're allowed to use to come to those beliefs. I'm only arguing about the definition of Science - and asking people not to say it's "Science" when it's not.

"And so the common man, lacking extraordinary wherewithal, is burdened with reckoning the difference between a good priest and a bad priest?"

No. The common man, lacking extraordinary wherewithal, is burdened with admitting that his wherewithal is lacking. The correct answer to such questions is "I don't know."

If you can't tell the difference between a good priest and a bad one, then you don't really know that it's good. You can't abdicate the responsibility for your judgements onto somebody else, because you're still responsible for choosing who to believe. If you lack the wherewithal to choose wisely, then some of your choices will be unwise. You might at least have the wisdom to know it.

If forced to answer, he might say "I still don't know, but this is the best I can do." I make no criticism of people's best efforts. If we were more modest about our own abilities, we might be a bit more forgiving when other fallible people choose differently.

"So I must ask, is this a failure of the faithful, or a failure of the priesthood? Does the corruption lie within the common man who lives according to the scripture as laid down by the clergy, or does it lie with the priests who've turned against the faith?"

The fault is the clergy's. But the corruption affects the congregation too.

To put it in terms of your consequentialist ethics, it matters not whether the corruption of the public understanding of science is deliberate or accidental, an error or a mistake, it still ends up being corrupted.

"Remember, Dan is asking the common man to have faith. He takes no position on the possible corruption of the clergy."

I'm not sure. His view earlier seemed to be that the clergy were probably immune, although he still seems to be open-minded on the question. We'll see.

March 6, 2015 | Unregistered CommenterNiV

> The argument behind it is that if a lot of scientists say it, and they've been doing their jobs, then it's probably been challenged and checked by all of them.

All of them? I've never seen anyone hold such belief. The problem with the Nullius in Verba injunction is always the "is" part.

As for the "ought" part, why should this be required? As if the auditing sciences answered the call of some kind of moral imperative.

March 6, 2015 | Unregistered CommenterWillard

"All of them?"

Yes. All of them.

As a certain climate scientist put it: "No scientist who wishes to maintain respect in the community should ever endorse any statement unless they have examined the issue fully themselves." If they've been doing their jobs, then they would have checked it before endorsing it. Proper scientists who haven't checked it would express no opinion - would say something like: "I don't know, it's not my specialism".

Scientists are not perfect, and even when doing their job competently might not always do it as thoroughly as they should on everything. There are always mistakes and omissions - hence the "probably".

Not all scientists are doing their jobs, though. And sometimes there is a confusion between a professional endorsement as a scientist and a personal opinion as a citizen. Scientists as citizens are as entitled to unscientific beliefs as anyone - so long as they don't try to claim them to be backed by science.

"As for the "ought" part, why should this be required?"

Because auditing is how the scientific method works, and the primary source of our justified confidence in its reliability. Without auditing, you undercut Science at its root. You destroy the justification for our confidence in it. You allow the errors in it to multiply and spread. You kill it.

And given that modern civilisation and the comfort, health, and prosperity of billions of people are built on the products of the scientific method, and the even greater prosperity of future generations will no doubt rely on our current Science remaining healthy, to undermine it risks widespread harm. We 'ought' not to do that.

March 7, 2015 | Unregistered CommenterNiV

> Yes. All of them. As a certain climate scientist put it: "No scientist who wishes to maintain respect in the community should ever endorse any statement unless they have examined the issue fully themselves."

This clarifies the claim that all scientists should "challenge and check" what a lot of scientists say. The reading should be: for all scientists and all scientific claims, a scientist S must challenge and check a claim C before endorsing C. This reading works because the word "endorsing" replaces "scientists say it":

The argument behind [an appeal to consensus] is that if a lot of scientists say it, and they've been doing their jobs, then it's probably been challenged and checked by all of them.

I still fail to see how this implicit premise is warranted because we have yet to know what kind of challenging and checking is required, and what kind of endorsement is presumed. Of all the mathematicians who build upon Fermat's last theorem by assuming its truth, there sure must have been a few who has never checked or challenged it the way Andrew Wiles did. Issues of plausibility and trust seem to me more complex than Wigley's huffing and puffing in Nullius' favorite email:

http://www.assassinationscience.com/climategate/1/FOIA/mail/0880476729.txt

Let it be noted that Nullius appealed to Wigley's authority.

***

> Scientists as citizens are as entitled to unscientific beliefs as anyone - so long as they don't try to claim them to be backed by science.

A consensus claim is a normative claim about a scientific claim. An ought of an is, so to speak. In "We (ought to) accept that AGW is the best explanation we have so far," the ought part is "we (ought to) accept that" and the is part is "AGW is the best explanation we have so far." A consensus claim needs both a normative and a factive component. A stronger claim would be "AGW is real and we ought to do something about it." It's not that stronger a claim, unless we accept that "AGW is real but we should do nothing about it" is a rational position, which is far from being obvious.

***

> Because auditing is how the scientific method works, and the primary source of our justified confidence in its reliability. Without auditing, you undercut Science at its root. You destroy the justification for our confidence in it.

It depends upon what is meant by auditing. Externally, science requires something like reproducibility and intersubjectivity. Internally, it requires something like consistency, simplicity, etc.

The auditing sciences built upon ClimateBall (tm) are far from following from these conditions. Take Dan's audit of his most immediate competitor. Very little in that post that would qualify as a scientific evaluation. It's more of a yawn than anything else.

March 8, 2015 | Unregistered CommenterWillard

"This clarifies the claim that all scientists should "challenge and check" what a lot of scientists say. [...] This reading works because the word "endorsing" replaces "scientists say it""

Not quite. The word "endorsing" replaces the word "say".

Consider:
"The argument behind [an appeal to consensus] is that if a lot of scientists [endorse] it, and they've been doing their jobs, then [the issue has] probably been [examined fully] by all of them."

Those who appeal to scientific consensus (whether they are scientists or otherwise) are assuming scientists behave as Wigley suggests, and therefore if a lot of scientists say/endorse a statement, they must all have checked it first, and that consensus is therefore evidence that many independent checks have taken place and been passed as required by the scientific method.

Does that help?

"Of all the mathematicians who build upon Fermat's last theorem by assuming its truth, there sure must have been a few who has never checked or challenged it the way Andrew Wiles did."

Indeed. And they shouldn't do that.

"Shouldn't" doesn't mean they don't.

"Issues of plausibility and trust seem to me more complex than Wigley's huffing and puffing in Nullius' favorite email"

Indeed they are. I have found a wonderful proof of it, too, but unfortunately this blog comment is too narrow to contain it...

But seriously, see the comments below the post here for some further clarification. A lot more could be said, though...

"Let it be noted that Nullius appealed to Wigley's authority."

Not really - or at least, not solely. Wigley had a particularly elegant way of putting it, but my argument justifying his sentiment is in the final two paragraphs.

However, for people who have faith in the authority of climate scientists, Wigley's statement could be taken as an authoritative one. And I did indeed quote it with the idea in mind that believers in AfA would thereby have to accept my conclusion - fallacious as that reasoning might be. That was possibly not entirely ethical of me. Bad NiV! Slapped wrist!

"A consensus claim is a normative claim about a scientific claim. An ought of an is, so to speak."

A consensus claim is an opinion survey, and an "is". Either 97% hold that opinion or they don't. Either it's been shown to be 97% or it hasn't.

It becomes a normative statement when people say: "You ought to believe because 97% of scientists say..."

"A consensus claim needs both a normative and a factive component."

There are (at least) two factual components and two normative components.
Factual claim 1: if we don't do something then the greenhouse will runaway and Earth will become like Venus.
Factual claim 2: 97% of climate scientists say that if we don't do something then the greenhouse will runaway and Earth will become like Venus.
Normative claim 1: We ought to believe that if we don't do something then the greenhouse will runaway and Earth will become like Venus because 97% of climate scientists say that if we don't do something then the greenhouse will runaway and Earth will become like Venus.
Normative claim 2: We ought to do something because we believe that if we don't do something then the greenhouse will runaway and Earth will become like Venus, which would be baaaaad.

FC1 is a question of climate science. FC2 is a social sciences question. NC1 is argument from authority. NC2 is an argument from normative economics. You could argue with any of them, separately.

"Externally, science requires something like reproducibility and intersubjectivity. Internally, it requires something like consistency, simplicity, etc."

Reproducibility is required so that auditors can reproduce it. No other reason.

"The auditing sciences built upon ClimateBall (tm) are far from following from these conditions."

True. :-)

March 9, 2015 | Unregistered CommenterNiV

@Dan,

Assuming consensus messaging IS effective: How much do you believe it should be emphasized, de-emphasized, or some combination of both?

;-)

March 16, 2015 | Unregistered CommenterBrad Keyes

@Willard and @NiV,

Wigley's authority and appeals thereto are not necessarily illegitimate, because (in the words quoted) he is not talking about how nature works. Appealing to authority or to consensus—i.e. a majority of authorities—is permissible in extra-scientific questions.

Not that NiV was really doing so, however.

Surely he was simply quoting Wigley's formulation of a normative truth that was understood and justified long before climate scientists existed.

March 16, 2015 | Unregistered CommenterBrad Keyes

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