Quando duvidar de um 'consenso' científico


Sexta-feira, Março 19, 2010




When to Doubt a Scientific ‘Consensus’

By Jay Richards16/03/2010 03:05

Filed under: Science & Technology, Big Ideas, Culture, Government & Politics, Public Square

Anyone who has studied the history of science knows that scientists are not immune to the non-rational dynamics of the herd.



A December 18 Washington Post poll, released on the final day of the ill-fated Copenhagen climate summit, reported “four in ten Americans now saying that they place little or no trust in what scientists have to say about the environment.” Nor is the poll an outlier. Several recent polls have found “climate change” skepticism rising faster than sea levels on Planet Algore (not to be confused with Planet Earth, where sea levels remain relatively stable).

Many of the doubt-inducing climate scientists and their media acolytes attribute this rising skepticism to the stupidity of Americans, philistines unable to appreciate that there is “a scientific consensus on climate change.” One of the benefits of the recent Climategate scandal, which revealed leading climate scientists manipulating data, methods, and peer review to exaggerate the evidence of significant global warming, may be to permanently deflate the rhetorical value of the phrase “scientific consensus.”

Even without the scandal, the very idea of scientific consensus should give us pause. “Consensus,” according to Merriam-Webster, means both “general agreement” and “group solidarity in sentiment and belief.” That pretty much sums up the dilemma. We want to know whether a scientific consensus is based on solid evidence and sound reasoning, or social pressure and groupthink.

Anyone who has studied the history of science knows that scientists are not immune to the non-rational dynamics of the herd. Many false ideas enjoyed consensus opinion at one time. Indeed, the “power of the paradigm” often shapes the thinking of scientists so strongly that they become unable to accurately summarize, let alone evaluate, radical alternatives. Question the paradigm, and some respond with dogmatic fanaticism.

We shouldn’t, of course, forget the other side of the coin. There are always cranks and conspiracy theorists. No matter how well founded a scientific consensus, there’s someone somewhere—easily accessible online—that thinks it’s all hokum. Sometimes these folks turn out to be right. But often, they’re just cranks whose counsel is best disregarded.

So what’s a non-scientist citizen, without the time to study the scientific details, to do? How is the ordinary citizen to distinguish, as Andrew Coyne puts it, “between genuine authority and mere received wisdom? Conversely, how do we tell crankish imperviousness to evidence from legitimate skepticism?” Are we obligated to trust whatever we’re told is based on a scientific consensus unless we can study the science ourselves? When can you doubt a consensus? When should you doubt it?

Your best bet is to look at the process that produced, maintains, and communicates the ostensible consensus. I don’t know of any exhaustive list of signs of suspicion, but, using climate change as a test study, I propose this checklist as a rough-and-ready list of signs for when to consider doubting a scientific “consensus,” whatever the subject. One of these signs may be enough to give pause. If they start to pile up, then it’s wise to be suspicious.

(1) When different claims get bundled together.

Usually, in scientific disputes, there is more than one claim at issue. With global warming, there’s the claim that our planet, on average, is getting warmer. There’s also the claim that human emissions are the main cause of it, that it’s going to be catastrophic, and that we have to transform civilization to deal with it. These are all different assertions with different bases of evidence. Evidence for warming, for instance, isn’t evidence for the cause of that warming. All the polar bears could drown, the glaciers melt, the sea levels rise 20 feet, Newfoundland become a popular place to tan, and that wouldn’t tell us a thing about what caused the warming. This is a matter of logic, not scientific evidence. The effect is not the same as the cause.

There’s a lot more agreement about (1) a modest warming trend since about 1850 than there is about (2) the cause of that trend. There’s even less agreement about (3) the dangers of that trend, or of (4) what to do about it. But these four propositions are frequently bundled together, so that if you doubt one, you’re labeled a climate change “skeptic” or “denier.” That’s just plain intellectually dishonest. When well-established claims are fused with separate, more controversial claims, and the entire conglomeration is covered with the label “consensus,” you have reason for doubt.

(2) When ad hominem attacks against dissenters predominate.

Personal attacks are common in any dispute simply because we’re human. It’s easier to insult than to the follow the thread of an argument. And just because someone makes an ad hominem argument, it doesn’t mean that their conclusion is wrong. But when the personal attacks are the first out of the gate, and when they seem to be growing in intensity and frequency, don your skeptic’s cap and look more closely at the evidence.

When it comes to climate change, ad hominems are all but ubiquitous. They are even smuggled into the way the debate is described. The common label “denier” is one example. Without actually making the argument, this label is supposed to call to mind the assertion of the “great climate scientist” Ellen Goodman: “I would like to say we’re at a point where global warming is impossible to deny. Let’s just say that global warming deniers are now on a par with Holocaust deniers.”

There’s an old legal proverb: If you have the facts on your side, argue the facts. If you have the law on your side, argue the law. If you have neither, attack the witness. When proponents of a scientific consensus lead with an attack on the witness, rather than on the arguments and evidence, be suspicious.

(3) When scientists are pressured to toe the party line.

The famous Lysenko affair in the former Soviet Union is often cited as an example of politics trumping good science. It’s a good example, but it’s often used to imply that such a thing could only happen in a totalitarian culture, that is, when all-powerful elites can control the flow of information. But this misses the almost equally powerful conspiracy of agreement, in which interlocking assumptions and interests combine to give the appearance of objectivity where none exists. For propaganda purposes, this voluntary conspiracy is even more powerful than a literal conspiracy by a dictatorial power, precisely because it looks like people have come to their position by a fair and independent evaluation of the evidence.

Tenure, job promotions, government grants, media accolades, social respectability, Wikipedia entries, and vanity can do what gulags do, only more subtly. Alexis de Tocqueville warned of the power of the majority in American society to erect “formidable barriers around the liberty of opinion; within these barriers an author may write what he pleases, but woe to him if he goes beyond them.” He could have been writing about climate science.

Climategate, and the dishonorable response to its revelations by some official scientific bodies, show that scientists are under pressure to toe the orthodox party line on climate change, and receive many benefits for doing so. That’s another reason for suspicion.

(4) When publishing and peer review in the discipline is cliquish.

Though it has its limits, the peer-review process is meant to provide checks and balances, to weed out bad and misleading work, and to bring some measure of objectivity to scientific research. At its best, it can do that. But when the same few people review and approve each other’s work, you invariably get conflicts of interest. This weakens the case for the supposed consensus, and becomes, instead, another reason to be suspicious. Nerds who follow the climate debate blogosphere have known for years about the cliquish nature of publishing and peer review in climate science (see here, for example).

(5) When dissenting opinions are excluded from the relevant peer-reviewed literature not because of weak evidence or bad arguments but as part of a strategy to marginalize dissent.

Besides mere cliquishness, the “peer review” process in climate science has, in some cases, been consciously, deliberately subverted to prevent dissenting views from being published. Again, denizens of the climate blogosphere have known about these problems for years, but Climategate revealed some of the gory details for the broader public. And again, this gives the lay public a reason to doubt the consensus.

(6) When the actual peer-reviewed literature is misrepresented.

Because of the rhetorical force of the idea of peer review, there’s the temptation to misrepresent it. We’ve been told for years that the peer-reviewed literature is virtually unanimous in its support for human-induced climate change. In Science, Naomi Oreskes even produced a “study” of the relevant literature supposedly showing “The Scientific Consensus on Climate Change.” In fact, there are plenty of dissenting papers in the literature, and this despite mounting evidence that the peer-review deck was stacked against them. The Climategate scandal also underscored this: The climate scientists at the center of the controversy complained in their emails about dissenting papers that managed to survive the peer-review booby traps they helped maintain, and fantasized about torpedoing a respected climate science journal with the temerity to publish a dissenting article.
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Read more here/Leia mais aqui: The American


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NOTA CAUSTICANTE DESTE BLOGGER:


Aqui neste blog, aqui e ali, eu digo: "Todas as vezes que você ouvir a palavra 'consenso', procure por sua carteira epistêmica, pois você pode estar sendo tungado!"


Fui, nem sei por que, pensando que a Nomenklatura científica vem tungando a carteira epistêmica dos cientistas há muito tempo. Ouse mijar fora do caco, oops, ouse pensar, falar e escrever diferente do paradigma: Inquisição sem fogueiras, destruição de carreiras acadêmicas, Gulag epistêmico. Eu sei do que estou falando. Alguns dos pontos acima eu já experimentei na própria pele enfrentando os mandarins da Nomenklatura científica.


Cruz credo!!!