What is Scientific Consensus?

What is Scientific Consensus?

There is much confusion about this term, particularly as it applies to anthropogenic global warming or climate change. Many people, who do not understand how science works, assume it means agreeing with popular view. For example, someone said, “a consensus isn’t always right. Science shouldn’t be based on following the crowd because you are too lazy or too scared to challenge false data”. Even science fiction writer Michael Crichton got it wrong. He wrote, “the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world.” (http://goo.gl/TgFmpb). So we were delighted to find this explanation by Filippo Salustri which is exactly how scientists view scientific consensus. 

Originally shared by Filippo Salustri

What is a scientific consensus?

I think there’s a couple of things wrong with this article in Scientific American.

1. The “message” from certain quarters – that anyone who doesn’t accept the scientific consensus on #climatechange  is stupid – is only one of many messages one can find “out there” these days.  There’s an implication that this is the only message available, which just isn’t so. I think this could have easily been treated with a couple of extra sentences, so I chalk that one up to a reporting error.

2. The deeper problem, for me, is the notion of “scientific consensus.” It is again implied that a scientific consensus is the same as any other consensus.  But I’m completely convinced that it is substantively different.

Conventional consensus (like political consensus, or organizational consensus) is often arrived at through argument and rhetoric; evidence is useful but not necessary. Conventional consensus is also an intensely social/collaborative affair.

Scientific #consensus is different.  Rhetoric plays a small (I’d say negligible) role.  Argumentation matters more.  But nothing beats evidence; it is the primary foundation on which scientific consensus is built.  Scientific consensus is what happens when a big pile of evidence (and all the information on how that information was collected and analyzed) is put before a group of scientists, who then work in relative isolation to recheck everything.  Different scientists will use different techniques to perform these checks.  New experiments done in new ways may be run to validate existing data.  From all this work, various conclusions are drawn, but even these are, in a way, data; they’re the results of rational argumentation from the evidence, and subjected to the same scrutiny as the original evidence itself.  If 100 scientists, each using their own methods, can all verify the evidence and then all reach the same conclusions by using their own analytic techniques – that’s a scientific consensus.  Indeed, a scientific consensus can be reached (at least in principle) without any of the participating scientists do any more than exchange evidence. There need be no significant collaboration, no social interaction, at all.

And this, as far as I’m concerned, is why a scientific consensus is far more robust than any other type of consensus.

In a way, it’s a lot like the multiple uses of the word “theory.” In science, it means something different than it does outside science.  Someone arguing that, say, “evolution is just a theory” is making the mistake of assuming the lay sense of “theory” applies within the scientific scope of evolution.  Same with “consensus” – the term denotes something substantively different within #science than it does outside it.

http://www.scientificamerican.com/article/how-to-determine-the-scientific-consensus-on-global-warming///cdn.embedly.com/widgets/platform.js