I am watchin Deep Impact tonight, a ten-year old film about a comet impacting the Earth. Why the Canadian History Channel is showing this film is a good question. Future history? Imagined history?
But putting that question aside, the movie made me go to Wikipedia again, and I ended up (re-)reading several articles there relating to the issue of global warming and controversies surrounding it.
One thing that struck me (and not for the first time) is this: criticism of global warming theories are often dismissed by the assertion that these go “against the mainstream” or are “not supported by scientific consensus.”
And global warming is by no means the only area of science where such arguments are frequently invoked. Take two topics that I have become involved with. There is scientific consensus that the inadequacy of Einstein’s theory of gravitation to explain the rotation of galaxies and large scale features of the universe is due to “dark matter” and “dark energy”. Even though no one knows what dark matter (or dark energy) is made of, and no one actually detected any dark matter or dark energy ever, the idea is treated as fact. True, dark matter theory can explain a few things and even made a few minor (but nonetheless impressive) predictions, but that doesn’t necessarily make it true, and it certainly doesn’t make the theory the only kid on the block worth considering. Still, try proposing an alternative gravity theory: no matter how firmly rooted in real physics it is, you will be fighting an uphill battle.
Or take the Higgs boson. This hypothetical particle (often along with the graviton) is often portrayed as if it has already been detected. It hasn’t. Indeed, the only thing experiments have accomplished to date is that they excluded the possibility that the Higgs boson exist at nearly the two-σ level. There are also significant unresolved issues with the Higgs boson that put the theoretical validity of the idea into question. Yet the “scientific consensus” is that the Higgs boson exists, and if you try to propose a quantum field theory without the Higgs, well, good luck!
Just to be clear about it, I am not saying that the climate skeptics got it right, and for all I know, maybe there is dark matter out there in abundant quantities, along with Higgs bosons behind every corner. But not because this is what the “scientific consensus” says but because the theory is supported by facts and by successful predictions. Otherwise, the theory remains “just a theory”, as the creationist crowd likes to say… neglecting the inconvenient fact that, of course, the theory of evolution is supported by an abundance of facts and successful predictions.