Harvard has been taking it on the chin lately, and I kinda hate to pile on, but here we have a Harvard prof, historian of science, who explains that we don’t need to prove climate change, we just need to believe. Question: Isn’t that religion?
Science is conservative, and new claims of knowledge are greeted with high degrees of skepticism. When Copernicus said the Earth orbited the sun, when Wegener said the continents drifted, and when Darwin said species evolved by natural selection, the burden of proof was on them to show that it was so. In the 18th and 19th centuries, this conservatism generally took the form of a demand for a large amount of evidence; in the 20th century, it took on the form of a demand for statistical significance.
We’ve all heard the slogan “correlation is not causation,” but that’s a misleading way to think about the issue. It would be better to say that correlation is not necessarily causation, because we need to rule out the possibility that we are just observing a coincidence. Typically, scientists apply a 95 percent confidence limit, meaning that they will accept a causal claim only if they can show that the odds of the relationship’s occurring by chance are no more than one in 20. But it also means that if there’s more than even a scant 5 percent possibility that an event occurred by chance, scientists will reject the causal claim. It’s like not gambling in Las Vegas even though you had a nearly 95 percent chance of winning.
See how she undermines science as we know it? Wouldn’t you gamble in Las Vegas if you had a 94% chance of winning? Of course you would!
Where does this severe standard come from? The 95 percent confidence level is generally credited to the British statistician R. A. Fisher, who was interested in the problem of how to be sure an observed effect of an experiment was not just the result of chance. While there have been enormous arguments among statisticians about what a 95 percent confidence level really means, working scientists routinely use it.
But the 95 percent level has no actual basis in nature. It is a convention, a value judgment. The value it reflects is one that says that the worst mistake a scientist can make is to think an effect is real when it is not. This is the familiar “Type 1 error.” You can think of it as being gullible, fooling yourself, or having undue faith in your own ideas. To avoid it, scientists place the burden of proof on the person making an affirmative claim. But this means that science is prone to “Type 2 errors”: being too conservative and missing causes and effects that are really there.
So, the 95% confidence level is imperfect; we miss some good stuff. Let’s dump it for religion.
Is a Type 1 error worse than a Type 2? It depends on your point of view, and on the risks inherent in getting the answer wrong. The fear of the Type 1 error asks us to play dumb; in effect, to start from scratch and act as if we know nothing. That makes sense when we really don’t know what’s going on, as in the early stages of a scientific investigation. It also makes sense in a court of law, where we presume innocence to protect ourselves from government tyranny and overzealous prosecutors — but there are no doubt prosecutors who would argue for a lower standard to protect society from crime.
When applied to evaluating environmental hazards, the fear of gullibility can lead us to understate threats. It places the burden of proof on the victim rather than, for example, on the manufacturer of a harmful product. The consequence is that we may fail to protect people who are really getting hurt.
And don’t you really want to save the children?
OK, if you’re still with me, she is now making the case for religion to replace science as we know it:
WHY don’t scientists pick the standard that is appropriate to the case at hand, instead of adhering to an absolutist one? The answer can be found in a surprising place: the history of science in relation to religion. The 95 percent confidence limit reflects a long tradition in the history of science that valorizes skepticism as an antidote to religious faith.
Even as scientists consciously rejected religion as a basis of natural knowledge, they held on to certain cultural presumptions about what kind of person had access to reliable knowledge. One of these presumptions involved the value of ascetic practices. Nowadays scientists do not live monastic lives, but they do practice a form of self-denial, denying themselves the right to believe anything that has not passed very high intellectual hurdles.
Are they denying themselves “the right to believe”? Why I thought that climate change was “settled science”! And most scientists believe in it. I’m surprised they can’t prove it to the 95% confidence level, to be honest, because I thought that was necessary in science. So… let’s change science to accommodate climate change.
Ok, Everyone, Time To Panic About Climate Change!!!