I was reading through a rant that someone posted on an atheist site today in which the poster claimed that science is only the religion of the moment and has no more to back it up than religion does. It's an odd claim to make, but upon reading more, I could see what the poster was trying to express, although the choice of terminology could have been better.
What he was trying to rail against was not science, but scientism. One is often mistaken for the other, and the term "scientism" is not well known. Scientism is a trap easily fallen into for many science-minded people. I find it difficult to define in any succinct way, but essentially it is a glorification of science beyond any reasonable level. The particular version of scientism argued against in the post, though, was the glorification of scientific results.
Science, by its nature, never arrives at an answer. One of its core ideas, really, is that you can approach knowledge, but you can never fully attain it. You put forth a hypothesis and test it out, and if your hypothesis is demonstrably better than every other hypothesis, it becomes the leading theory on whatever it is about. But if someone else comes along with a better one, well, yours is gone. There is a constant progression toward knowledge without ever a true acquisition of it. Even something as seemingly obvious as Newtonian physics was upended when Einstein came along with something better. Nothing is sacred, and nothing is set.
However, one who has fallen into the scientism trap will often take whatever the latest consensus is on a given topic and treat it as irrefutably proven. Let's look at global climate change as an example. All the evidence we have points to it being real and being influenced by human activity. As it stands now, that is the overwhelming scientific consensus. It could be wrong, and all true scientists must admit that it could be wrong, but it represents the best explanation for the data that we have.
The general public has a hard time with the lack of certainty in science. Unscrupulous talking heads will often prey upon this by sowing an inordinate amount of doubt in a scientifically reached consensus. There is usually some political or personal motivation behind this. Someone will go on television to point out some perceived inconsistency, claiming it refutes the consensus view. It can be very tempting for a scientist or a science-minded person to counter back with a claim that the consensus view is irrefutable fact. This is one of the traps of scientism. It is unscientific to claim any fact is irrefutable.
This doesn't mean we shouldn't consider global climate change to be a real and legitimate threat. If we were to wait around for things to be proven before acting on them, we'd never do anything. We all have a threshold beyond which we consider something to be proven well enough to act on. It's important to keep that threshold consistent and to understand what it is. Science is a tool to help us do that. When scientists write up results, they usually include a confidence interval, which basically gives you an idea of how likely their conclusion is correct based on the data. The confidence interval is never 1.00 (a "perfect score"). Acknowledgement of the possibility of error is built into science.
Most scientists do understand this, but it's very hard for the human mind to handle uncertainty well, it seems. We find what we think works and we stick to it, and we're loath to admit when we're wrong. We don't want our personal philosophies to be undermined. We aren't logic machines. Science is an acknowledgement of that, and it presents us with a way to move forward without denying the uncertainty.