The American public is slowly coming around to the idea that global warming is real, but there are a significant number of scientists at this point who believe we may be too late to do anything about it. As one of the biggest contributors of greenhouse gases to the atmosphere, our failure to accept that global warming is happening threatens to become an epic tragedy that historians will sadly puzzle over centuries from now, assuming we don’t roast ourselves before that.
The US has always been an epicenter of science skepticism. There are several reasons for this. One is that Americans tend to be independent, self-reliant people. There is nothing wrong with a bit of independence, but when it causes one to make ignorant and harmful mistakes, it has gone too far. The world is complicated but we need to arm ourselves with knowledge in several different areas in order to achieve our goals: health and medicine, finance, education and politics to name a few. An effective thinker knows when to use the work of others and is able to gauge how much trust to put in it.
Another source of this skepticism is a misunderstanding about the nature of accepted scientific results. They are not engraved in stone. They represent no more than our best theories at this time. As science progresses, they will be corrected and augmented and probably ultimately be discarded in favor of more effective theories. But our best course of action as independent decision makers is to arm ourselves with as much of our current scientific knowledge that we can.
In this post I will sketch three reasons why science is generally worthy of our trust.
The unity of science
Creationists are some of the biggest science skeptics. They believe that their dispute is only with a branch of biology known as evolutionary biology. But this branch of biology is connected by thousands of chains of evidence and reasoning to the rest of biology. The genome of an organism, for instance, relates to the development of that organism as well as its evolution. Certain branches of chemistry are inferentially nearby,such as molecular genetics. These branches of chemistry are in turn connected by thousands of lines of evidence and reasoning to the rest of chemistry. Creationism also contradicts astronomy, since astronomy tells us that the earth is billions of years old, and that the surrounding universe is several billions years older. There is light just now reaching this planet that has been traveling for billions of years. Likewise, the same carbon 14 dating that allows us to attach dates to fossils and other organic material is thoroughly connected to modern physics via thousands of inferential links. Creationism also contradicts fundamental tenets of geology, such as the idea that geological layers are deposited over millions of years. Taking on one branch of science is like picking a fight with one member of a very close family: fight one of them and you must fight them all.
The entirety of science could still be mistaken, but the unity of science argument makes it clear that the creationist’s choice is a bitter one. He is not merely choosing an alternative account of the origins of animals, he is choosing an entirely different way of life. He must disbelieve and attempt to refute the entirety of science and its accumulated knowledge. The more you go against orthodoxy, the greater your burden of proof. Given this, the burden of proof on creationism is heavy. They need to make bold claims about what their theory predicts and verify them, and this has not happened.
The connection between science and technology
Science and technology are connected via millions of threads of inference. For instance, Einstein made a scientific breakthrough that led via a chain of inference to a technological breakthrough: nuclear power. Sometimes people follow threads in the other direction, seeking to understand an existing technology by extending scientific theories. While we have mastered the technology of anaesthesia, for example, we still do not have an adequate scientific understanding of what exactly it does to the brain.
To be consistent, extreme science skeptics such as creationists should not trust any existing technology. They should not use computers, drive modern cars, fly on airplanes, or have an MRI done, since the same science that tells us that animals evolved created these technologies. But of course these are reliable technologies. The best explanation for this fact and the fact that our cars go, our bridges do not fall down, hospital patients get better at ever-improving rates, and so on, is that the science behind these achievements correctly describes the world.
Science’s system of checks and balances
Science skeptics often speak as if the entire scientific community is engaged in a secret conspiracy. As with many of their charges, there is a certain amount of truth here. Science is subject to fads and to other non-scientific factors. Just as do all humans, scientists tend to form cliques and in-groups who delight in keeping out interlopers, usually for reasons having nothing to do with the scientific merit of their work. But there is one immensely powerful force that keeps science objective and scientists honest: competition. There are two ways an ambitious young scientist can make a name for herself. First, she can make some important new discovery. But this can take a lifetime to achieve. However, there is a second, quicker route to success. She can show that some well accepted claim or theory is false. Established scientists are like aging gunfighters: They know that there are plenty of young guns waiting to take them out if they make a mistake. If a scientist publishes results that other scientists are unable to replicate, this is a substantial blow to the reputation of that scientist. Aging scientists also know that they must stay up to date on recent discoveries in their field, otherwise they won’t be able to get their work published, since every science article must begin with a review of the current state of the literature.
Before a study can be accepted as part of the scientific canon, albeit temporarily, by being published in a scientific journal, it must pass several tests. First, the authors typically must possess an advanced degree in the relevant field. Ph. D.’s and M.D.’s are not easy to get. Early in their training, students are in a massive learning phase, where they are tested constantly. Later in their training, they must prove that they can conduct independent research, under the supervision of a committee of five or so professors. Second, every journal has a review process in which a submitted article is sent to three referees who are among the world’s best experts in that field. Hence they are in competition with the authors of the article they are reviewing. The referees then return a review of the study, along with their opinion on whether it merits publication. In the case of a mixed verdict, the editors of the journal may ask for the opinion of additional referees, or may decide to publish or not based on the content of the reviews, along with what they know about the characteristics of the particular referees involved. These referees, by the way, are not paid anything for their work, they offer their opinions are part of belonging to a community of scientists.
The bottom line is not that scientists are unbiased. To be human is to be biased. But science as a whole minimizes its sources of bias by allowing them to cancel each other out. To reject science is to reject a significant portion of the whole human project. It amounts to rejecting the idea that knowledge is possible. Any rejection of science, furthermore, should be based on good reasons, i.e., it should be based on knowledge. And to reject the possibility of knowledge by using knowledge amounts to a contradiction.