Sarewitz on “Consensus Science”

This piece is reposted from Roger Pielke’s blog here. Note from Sharon: we have been discussing collaborating in terms of developing agreements about what action to take; I see a clear distinction between their use in policy (getting groups together to decide or recommend an approach or action) and in science (getting groups together to determine the current scientific thinking).

The below post by Roger, describing some of the ideas in Dan Sarewitz’s piece in Nature, deals with the latter. I don’t think we do much in terms of this in the world of public land management, which may be a good thing. Also note a comment here on Roger’s blog by Andy Stahl about consensus policy; some think that committees are places where good ideas go to die.

Writing in Nature this week, Dan Sarewitz reflects on his recent participation on the BPC Geoengineering Climate Remediation task force and why efforts to achieve consensus in science may leave out some of the most important aspects of science. Here is an excerpt:

The very idea that science best expresses its authority through consensus statements is at odds with a vibrant scientific enterprise. Consensus is for textbooks; real science depends for its progress on continual challenges to the current state of always-imperfect knowledge. Science would provide better value to politics if it articulated the broadest set of plausible interpretations, options and perspectives, imagined by the best experts, rather than forcing convergence to an allegedly unified voice.

Yet, as anyone who has served on a consensus committee knows, much of what is most interesting about a subject gets left out of the final report. For months, our geoengineering group argued about almost every issue conceivably related to establishing a research programme. Many ideas failed to make the report — not because they were wrong or unimportant, but because they didn’t attract a political constituency in the group that was strong enough to keep them in. The commitment to consensus therefore comes at a high price: the elimination of proposals and alternatives that might be valuable for decision-makers dealing with complex problems.

Some consensus reports do include dissenting views, but these are usually relegated to a section at the back of the report, as if regretfully announcing the marginalized views of one or two malcontents. Science might instead borrow a lesson from the legal system. When the US Supreme Court issues a split decision, it presents dissenting opinions with as much force and rigour as the majority position. Judges vote openly and sign their opinions, so it is clear who believes what, and why — a transparency absent from expert consensus documents. Unlike a pallid consensus, a vigorous disagreement between experts would provide decision-makers with well-reasoned alternatives that inform and enrich discussions as a controversy evolves, keeping ideas in play and options open.

Not surprisingly, Dan and I have come to similar conclusions on this subject. Back in 2001 in Nature I wrote (PDF):

[E]fforts to reduce uncertainty via ‘consensus science’ — such as scientific assessments — are misplaced. Consensus science can provide only an illusion of certainty. When consensus is substituted for a diversity of perspectives, it may in fact unnecessarily constrain decision-makers’ options. Take for example weather forecasters, who are learning that the value to society of their forecasts is enhanced when decision-makers are provided with predictions in probabilistic rather than categorical fashion and decisions are made in full view of uncertainty.

As a general principle, science and technology will contribute more effectively to society’ needs when decision-makers base their expectations on a full distribution of outcomes, and then make choices in the face of the resulting — perhaps considerable — uncertainty.

In addition to leaving behind much of the interesting aspects of science, in my experience, the purpose of developing a “consensus” is to to quash dissent and end debate. Is it any wonder that policy discussions in the face of such a perspective are a dialogue of the like minded? In contrast, as Sarewitz writes, “a vigorous disagreement between experts would provide decision-makers with well-reasoned alternatives that inform and enrich discussions as a controversy evolves, keeping ideas in play and options open.”

4 thoughts on “Sarewitz on “Consensus Science””

  1. Not discussed here is the challenge of reaching consensus on largely scientific issues of forest management within a group that includes both laymen and scientists with experience and training in forest management. For instance, the details and use of old-growth guidelines on projects that propose logging. Often individuals with very divergent backgrounds are at the table in roles treated as “equals” dealing with science. Transform this scenario to a hospital setting where the family groups with the surgeons in the waiting room to reach agreement on a serious medical procedure. Would you want to be the patient awaiting the outcome of this consensus group?
    I would agree with the suggestions that minority opinions or recommendations be given full disclosure and consideration by the final decision makers. But a comparison of forest management consensus groups to the supreme court is weak, in that the court judges are all top-of-the-line, highly trained/experiences attorneys, No persons off the street!
    No easy answer to this dilemma. Challenge is for the scientists to educate the laypersons to the point where they are reasonably comfortable with a scientifically solid range of alternatives.

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  2. Ed- You raise an interesting point, especially with your analogy.

    What happens is that practitioners advise the patient. Any good patient, or patient advocate, wants to understand why Doctor X disagrees with Doctor Y. Of course, because of my background I have a good biological training so I enjoy finding out the details more than others- but I think anyone would prefer to have them discuss it where they can hear. Otherwise it might be that Doctor Y is tyrannical and overbearing and Doctor X doesn’t feel like/doesn’t have time to get involved in a big discussion about it, so Doctor Y never even heard Doctor X’s point of view.

    Most of the cases we are discussing here on the blog are not exactly particle physics in terms of complexity. They are about known species (some eminently observable, such as grizzly bear), what they like to do and eat, what conditions are and what they might turn into with a fire. I bet that there are a substantial number of folks in that community who have direct experience, both with grizzlies and with conditions after a fire.

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  3. Consensus is not a scientific process, it is a political process. The climate change debate is highly politicized. Science, advocacy, and politics have become intermixed to the detriment of the science. Much of the so called science has devolved into mudslinging, name calling, and character attacks rather than actual science.

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  4. Unfortunately Michael D is correct. But I personally, after expending loads of time and energy in a IPNF consensus group, am not comfortable with this mixing science with politics. Or “in my opinion” this is what we should do type of decision-making. Possibly this explains the demise of this group. Some good people with good backgrounds, but that was not enough.

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