Wednesday, March 06, 2013

The expert exception to consensus reliance

I've really enjoyed Chris Mooney's Point of Inquiry podcasts, so it's too bad the latest one with pro-GMO activist Mark Lynas failed to wrestle significantly with real arguments about GMOs (Chris, you talk about GMOs too much to say you don't want to delve into technical issues).

One interesting issue did come out of the podcast - at one point Lynas says the Union of Concerned Scientists' rejection of the National Academy of Sciences position on GMOs is a contradiction of UCS arguments that we should rely on the consensus opinion on climate change.  I've argued something similar before, that the expert consensus should basically just plug in as fact in policy discussion, but there's one exception - if you yourself are an expert in that field, I think you could conclude that you're right and the consensus is wrong.  Presumably UCS could make this conclusion.

It takes a lot of hubris to conclude you're right and the other 90% of the experts are wrong. You might carefully examine whether you're missing something little or something big, and withhold judgment for a while. In the end though if you feel like you really understand the issue, you don't have a choice but to conclude what you conclude.

So what should happen next depends on who you are.  If you're the dissenting expert, you should work to move the consensus in your direction.  If you're someone else, the dissenter is just a dissenter, and only if there's enough of them to disrupt the consensus do we need to worry about them.

So no change to the big picture, but I disagree with Lynas that experts are required to toe the line of an expert consensus when they disagree with that consensus.

13 comments:

carrot eater said...

Well, does UCS actually include real, publishing experts in this field? Is UCS disputing any science, or is it just giving a different spin on policy implications?

(I don't know, and care too little to go find out myself, but care enough to ask the question here. I freely admit laziness).

Brian said...

Seems like they've got experts, e.g.:
http://www.ucsusa.org/about/staff/staff/margaret-mellon.html

a_ray_in_dilbert_space said...

Brian,
I do not think that scientific consensus can be measured as a simple "vote". All the science can do in a case like this is establish whether there are risks, and perhaps whether there are feasible mitigations for the risks. Individual researchers and organizations of "experts" can disagree about whether the risks are manageable and about whether the payoff makes them worthwhile.

Your position, however, could be misinterpreted. In your mind, is it OK for Richard Lindzen to pontificate in the Wall Street Urinal (ex cathedra, so to say), or for Roy Spencer to do likewise?

How about Pat Michaels' testimony to Congress, or our "honest broker," Roger the Dodger. I would point out that no one censors these individuals--despite their ludicrous and sometimes dishonest claims. However, no one is required to take what they have to say seriously, either, since they present no coherent framework for advancing the state of the discipline.

By all means, and expert is entitled to consent from the consensus, but if they expect to receive any respect for their position, they had better understand the consensus well and it behooves them to present a coherent alternative.

Jay said...

'Is it OK for Richard Lindzen to pontificate in the Wall Street Urinal...'

Yes.

It's for said periodical to decide how it wants to frame its coverage of course - false balance being a something any sage publication would wish to diligently avoid. But the point of consensus is so the rest of us (the sensible ones in any case) can make some sort of non-silly judgement on what's what even when there's differing voices whispering in our long fluffy ears.

On Lynas - I don't think there's actually a scientific consensus that GMO oranges are the only fruit.

a_ray_in_dilbert_space said...

FWIW, I draw a big distinction between dissent in scientific discussions and broadcasting a minority opinion on unsophisticated laymen. The former is part of the scientific process. The latter is very close to scientific misconduct.

Marion Diabolito said...

If you want to present what "science thinks" about something, you really only have two choices: pick a minority, and claim they're right, or go with a majority of scientists with relevant education and training.

This is heavily gamed by the nuke promoters and GMO promoters, frankly. That said, all of us promoting the climate science consensus never said, e.g., Linzen or Curry or whoever should themselves support or agreewith parts of the consensus they disagreed with; they have the relevant training to be experts on some parts of the issue. I do think Brian is right about that principle: if you're an expert, your dissent is part of the process. If you're REPRESENTING THE SCIENTIFIC CONSENSUS TO THE PUBLIC, you MUST use "science believes" and "the majority of relevant scientists believe" as synonyms. Anything else privileges a minority and is advocacy, not reporting. Right now, it really is the consensus that GMO foods don't significantly increase, say, allergies. So far. Because a majority of food allergy experts who've conducted or analyzed research on them say so.

Let me give you an example, also from Chris Mooney - and one I think that shows he often gropes for balance for balance's sake. Understandably, since he also has gone the farthest I know of in pointing out where balance is lacking in reality:

To "show" that "liberals" also use almost as much motivated reasoning, he had on a nuke-pusher or false-balance pusher (my take) who pointed out that in his poll the "liberals" didn't know the scientific consensus on whether deep ocean ridges were a safe place to dispose of nuclear waste.

Well.

Let me start listing the problems with that bullshit, starting with the biggest one:

No news stories or popular accounts I am aware of have discussed what the scientific consensus is on that. It's always been about finding dumping sites, always on land, and binding waste material in compounds to sequester it, etc. All the coverage of it as a science issue has involved that. In fact, other than the ubiquitous coverage on where disposal sites should be (on land, sequestering), the only other discussion on it in the public arena is disposing of it via breeder reactors of various sorts, including thorium reactors.

So NO ONE outside a small and select group is going to know what the scientific consensus is on the safety of dumping radioactive waste into deep ocean ridges. Conservatives would be guessing just as much as liberals, and the guest was simply approving their guess. In fact, this is a push poll. He thinks we SHOULD be doing that, and he selectively asked scientists (again, my take from what he said) if that was okay, and blam, it's the scientific consensus. Quick, do liberals know the scientific consensus on whether It's "safe" to one day use a space elevator to move radioactive waste out to the Moon?

Another glaring problem, of course, is that the poll didn't say FROM WHICH ASPECT OF SCIENCE it's supposed to be safe or not! My strong suspicion is that in "finding" the scientific "consensus" on whether its "safe" he didn't consult mainly experts on the ecology and biology of life in deep ocean ridges. Even if he did, he still should have said, according to a consensus of marine biologists specializing in deep ocean ridges, would proposals such as have advanced to dispose of radioactive waste in deep ocean ridges ecologically safe? Again, my take: he consulted with nuke-boosting radiation experts and they only considered human impact.

The average person polled about that is not going to have any mass media resources whatsoever. All they're going to know is, we don't seem to be doing that now. So, probably, it's NOT safe or we wouldn't have the NIMBY fights over where to dump the waste. His push poll message is, you dummy, science says it's a great thing to do - so which group of dirty hippies must be stopping us?

Robert Grumbine said...

Consensus is a sadly misunderstood term, which contributes to many problems in public discussion. The misunderstanding being to think that everybody involved is in total agreement on all points that are in the consensus document. It's a particularly stupid for people in the US to make this mistake since our Constitution was a consensus document -- and any even elementary school understanding of how it was written makes it plain that everybody who signed disagreed with at least some of it.

For science topics, that's no less important. So, yes, I agree with the Brian that experts may, actually I'd say _should_ disagree with the consensus. More precisely, should discuss the how and why of their disagreement with the consensus. It is still consensus, and it's important to know what the consensus says. But the consensus is never entirely correct, hence constitutional amendments and supreme court reinterpretations. So discussion of the hows and whys of disagreement point to where and how the consensus might change in the future.

On the pragmatic side for climate, the lie that there's some massive conspiracy of climate scientists is undercut by obvious evidence of our disagreements with each other. But, then, pragmatically, it doesn't make much difference as the people who cling to that view are pretty immune to evidence.

carrot eater said...

"So NO ONE outside a small and select group is going to know what the scientific consensus is on the safety of dumping radioactive waste into deep ocean ridges."

and thus, if the respondent is intellectually mature, the response should be "I don't know."

Sadly, we don't see that - you could pretty much create a survey question about something completely imaginary, and people will end up voting on it the way they think they ought to, based on political or religious persuasion.

in the end, as always, people are idiots.

Brian said...

No problem with honest dissenters saying what they believe publicly, so long as they admit the consensus exists. They should also admit the public shouldn't be relying on the dissenter's opinions, and see if they can come up with policy arguments that don't depend on outlier scientific positions.

John Mashey said...

Consider reframing this discussion:

1) Science: what do we know or not about the real world and with what level of uncertainty? What are known/unknown risks? (i.e., Cheney actually is useful: knowns, known-unknowns, unknown-unknowns.)

2) Engineering: what can we {build, geoengineer, genetically-modify} now, 10 years from now, etc? And what are the cost curves? And what are known/unknown risks?

[Of course, science & engineering interact, as in using scientific methods to measure the effects?

3) Policy: Given the best information from 1) and 2), and maybe some economics/politics knowledge, what *should* we do?

When these get mixed together, confusion can occur. For instance:

1) Climate science: strong consensus on many things, well-studied uncertainties, strong predictions of problems for BAU.

2) Geoengineering: really don't know much by comparison, and even people who agree on 1) may disagree on 2), even as to whether it should even be evaluated.

3) Policy: a disagreement or two about this, sometimes even from people who agree on 1), don't think there is much hope for 2), but may argue carbon tax vs cap-and-trade. Of course, others start from policy and work backwards to denying consensus 1).

Now: GMO:
1) Science tells us much about how this can be done, and a lot more than we knew 50 years ago.

2) Engineering: humans have been modifying food since agriculture started, very little we eat is "natural." Pasta is mostly made from wheat varieties created via radiation or chemical mutation, etc, etc. On the other hand, GMO is new enough, and with potentially negative side-effects, that there is room for argument about risk. Unlike AGU, where BAU is a problem, BAU (don't create any more GMOs) is not so obviously a problem.

3) Policy: lots of tricky questions here, intertangled with fact that people conflate GMO in general with Monsanto, for example. Some interesting questions:

a) Suppose plant breeding creates a valuable new cultivar ... and a GMO process creates exact the same thing. Is one of them OK and the other not?

b) Suppose some branch of IIT creates a new GMO cultivar that reduces hunger across India? OK, or not? And who gets to say so? Suppose a US agribusiness creates that?

c) Suppose climate change causes need for fast adaptation, as for drought or saltwater tolerance? Standard breeding can be slow. How much faster would GMO have to be to become OK?

d) Wheat rust is bad news, because unlike c), it can happen fast, and unpredictably. See The Economist, 2010, including Borlaug's efforts and interactions with climate. These are like the flu: they mutate.

e) And of course, biological entities reproduce. The world has plenty of examples of things that "seemed like a good idea at the time" such as kudzu in the US South (well, heading for Southern Ontario), Eucalyptus in California, rabbits and cane toads in Australia, worse than the rabbits, which at least can be eaten, although apparently the Aussies have developed sports like "cane toad golf" and "cane toad cricket" and some make purses of them, but they otherwise seem worse than useless. Hence, if some people may seem to over-emphasize GMO risks, they may have reason to want to be careful.

So, I do not suggest answers to these questions, simply that to argue about 3), one needs to have a good understanding of 1) and 2), and think about the sorts of questions above.

Anonymous said...

Nice framing, Dr. Mashey. Regarding your item no. 3, policy, we have an Alice-in-Wonderland example of the putatively "public" University of California filing an amicus brief to the U.S. Supreme Court, arguing that UC would be "harmed" if Monsanto loses their case. To me, this would appear to be a self-refuting brief, or at least very strong evidence that the Court should reject Monsanto's argument. Why should a "public" university feel the need to waste its resources defending its corporate sponsor? This seems to be an absurd and perverse proposition that has nothing to do with the university's mission.

Taylor B

Gator said...

Experts should always advocate their understanding of their expertise, whether it supports or contradicts the consensus in that field. They should be prepared to support their position -- that's what makes them experts.

If they can't sustain an argument in scientific circles, they are not an expert (at least not in that field.) People can say whatever they want in editorials and such, and it is up to us to decide whether we believe the propaganda pushed at us by non-experts.

In an ideal world non-experts would keep their yaps shut but we all know we don't live in an ideal world.

a_ray_in_dilbert_space said...

Gator,
In scientific circles, I agree. In front of the general public, there has to be more deference given to the consensus--particularly a strong consensus.

When I was in grad school, we had a particle physics theorist who didn't believe in quarks. He simply was not allowed to teach particle physics.