There is an oft-repeated phrase that has been bothering me for a while now. During an interview with George Stephanopoulos on ABC, former Vice President Al Gore said that “the debate in the scientific community is over” regarding global warming. Really? I have long had a problem with the idea of consensus being the way scientific truths are judged. All it takes — all it should take, anyway — for a commonly-held belief to be overturned is for one voice to propose a new theory that explains the facts better. Scientists don’t vote on whether E=mc2 is true; they judge whether the theory best explains the data. And that theory, once it has proven useful in explaining the facts, will continue to be tested by other scientists; if it fails to explain real-life results, scientists will look for a new and better theory.
History is full of examples of the commonly-held consensus being wrong. Here’s a few as listed on Wikipedia, quoting The Structure of Scientific Revolutions by Thomas Kuhn:
- the theory of continental drift proposed by Alfred Wegener and supported by Alexander Du Toit and Arthur Holmes but soundly rejected by most geologists until indisputable evidence and an acceptable mechanism was presented after 50 years of rejection.
- the theory of symbiogenesis presented by Lynn Margulis and initially rejected by biologists but now generally accepted.
- the theory of punctuated equilibria proposed by Stephen Jay Gould and Niles Eldredge which is still debated but becoming more accepted in evolutionary theory.
- the theory of prions -proteinaceous infectious particles causing transmissible spongiform encephalopathy diseases- proposed by Stanley B. Prusiner and at first rejected because pathogenicity was believed to depend on nucleic acids now widely accepted due to accumulating evidence.
- the theory of Helicobacter pylori as the cause of stomach ulcers. This theory was first postulated in 1982 by Barry Marshall and Robin Warren however it was widely rejected by the medical community believing that no bacterium could survive for long in the acidic environment of the stomach. Marshall demonstrated his findings by drinking a brew of the bacteria and consequently developing ulcers. In 2005, Warren and Marshall were awarded the Nobel Prize in Medicine for their work on H. pylori
I particularly like the last one, because I remember when scientists finally started to accept the idea that stomach ulcers were produced by a bacterium rather than spicy foods.
Anyone who brings up the “scientific consensus” argument is making a logical fallacy known as “appeal to authority;” basically, the argument goes, “Global warming is real because Al Gore tells me it is real.” It’s the same false argument as the old parental favorite, “Because I’m the Mom, and I say so.” But while these examples point out the pitfalls of consensus, they didn’t point to a particular article I remembered reading a while ago about the problem of scientific consensus; that article caused me to distrust anyone who claims consensus as a valid reason to support global warming theory.
And then I found it again, and it was written by an author I hadn’t suspected: Michael Crichton. I have several of his books, and they can be a fun read, but Crichton’s nearly-constant pessimistic theme of “mankind can’t be trusted to handle science or technology” can really grate on my nerves. However, Crichton does have an interesting view of “consensus science.” He delivered a lecture, humorously titled “Aliens Cause Global Warming,” at the California Institute of Technology in January of 2003. Here are two relevant sections from that lecture, regarding scientific consensus:
There is no such thing as consensus science. If it’s consensus, it isn’t science. If it’s science, it isn’t consensus. Period.
… I would remind you to notice where the claim of consensus is invoked. Consensus is invoked only in situations where the science is not solid enough. Nobody says the consensus of scientists agrees that E=mc2. Nobody says the consensus is that the sun is 93 million miles away. It would never occur to anyone to speak that way.
Read the whole lecture. For one thing, if you do, you’ll understand the link between aliens and global warming. I have a minor beef with the lecture, since Crichton makes this link at the beginning of his lecture, but he fails to reiterate the link at the end. My high school English teacher drilled into my head that a thesis paper needs to have the thesis stated at the beginning and reiterated for reinforcement at the end. But Crichton is being paid for his writing, and I am not, so what do I know?
Interestingly enough, this same lecture by Crichton was also the source for my dislike of the Drake equation about which I recently wrote. I had first heard the Drake equation in Carl Sagan’s Cosmos TV series and book, back in the early ’80s, but it took me until the 2000s to realize that anything multiplied by guesswork becomes a guess, and that is why I dislike the “consensus” argument on global warming. It’s science multiplied by politics multiplied by guesses, and no matter how many times Al Gore may say that scientists have achieved consensus on the subject, that still ain’t how science works.