Proponents of the idea of human-induced global warming often claim that there is an overwhelming consensus among scientists that such warming is a fact. For example, consider this recent article:
Consensus Confirmed: 97 Percent of Climate Papers Agree on Manmade Global Warming
by Brendan DeMelle, 22 June 2013 Huff Post Green
“A new survey conducted by a team of volunteers at Skeptical Science has definitively confirmed the scientific consensus in climate science literature — 97 percent of peer-reviewed papers agree that global warming is happening and human activities are responsible.
“It does not get any clearer than this. It should finally put to rest the claims of climate deniers that there is a scientific debate about global warming. Of course, this bunch isn’t known for being reasonable or susceptible to facts. But maybe the mainstream media outlets that have given deniers a megaphone will finally stop…”
The problem with grandiose statements such as the one above is that consensus is simply a collection of opinions, it is not scientific proof. In fact, when “consensus” is presented as “proof” then you can be sure that the presenters do not actually have verifiable proof. Instead they are merely practicing junk science.
And what about the opinions of those scientists who hold a minority view? Should their opinions be ignored because they have less votes than the majority? No, of course not. The role of true science is to determine which group is correct.
Science converges on the truth by requiring that scientists provide verifiable
evidence of a hypothesis, not by counting scientists’ votes for or against the hypothesis
Still not convinced? I agree that it may seem intuitive that scientists’ beliefs, as confirmed by a consensus of their peers, should be used to guide us when proof is not available. But this is just gambling; there have been numerous times throughout scientific history when the consensus of scientists has been completely wrong. For example, at one time the near-unanimous consensus of doctors was that it was perfectly fine to perform their work without first washing their hands: see “Advice From Professionals: Who Do You Trust? (Part 2).” (For other reasons to be cautious about allowing intuition to be our guide, see “Why Not Go With The Gut?“)
Bottom line: Those who promote “consensus” as being equivalent to a scientific proof do not understand how science works, and should be ignored.