It isn’t. It really isn’t. It is a set of techniques for statistically measuring and evaluating the world, and comparing the results of those measurements with what theory says should be happening. If the measurements don’t match, the theory is discarded. If the measurements match, the theory is tentatively held to be true — until other data comes in that, most of the time, refines the theory rather than overthrow it entirely. For example, Einstein’s theory of relativity did not overthrew Newtonian physics. Rather, it found that Newton’s equations were a fine description of how things worked at low speeds, but did not work as you approached the speed of light. We sent Apollo to the moon using Newtonian physics, because everything was at slow enough speeds that Newtonian physics was accurate enough. This despite the fact that Einstein had proven over 50 years prior that Newtonian physics was not an accurate description for how mass, speed, force, and acceleration interacted as the speed of an object approaches the speed of light.
This tentativeness confuses people raised to believe there are truths that are handed down by God, Mommy, or Preacher Bob. They think this makes science somehow inferior to their handed-down truths, which have no such tentativeness attached to them. But this tentativeness is exactly why science has been so successful at improving our quality of life, decidedly more successful than God, Mommy, or Preacher Bob. This very computer that you’re reading this on is proof enough that science works. Yet there are people who, if they read this, will deny that fact, and claim that science — things like evolution, global warming, etc. — is a “liberal conspiracy” because of that tentativeness, that inherent lack of absolute truth that characterizes science. Science cannot provide absolute truth, because the universe is too large for human brains to comprehend, but science can provide approximations of truth — like the Newtonian equations — that are “good enough” until refined further by later scientists to create a better approximation of reality.
In short, the inherent tentativeness of science is not a reason to claim science is a liberal conspiracy. Rather, it exists because that’s how science works. Sometimes awkwardly, sometimes heading down wrong paths for decades, but there are no sacred cows in science. There are only measurements, and theories to explain the measurements. And of the two, only the measurements are held as true, and only if they can be repeated by third parties using different methods. Such as, for example, the multitude of methods that have been used to approximate global temperatures over the past 2,000,000 years, which show that the Earth is warming rapidly right now in a way that hasn’t been seen anywhere in the lifespan of humanity on this planet, and that this rise has been correlated with a steep rise in carbon dioxide concentrations in the atmosphere. At that point the question becomes not, “is global warming happening”, but, rather, “how much of global warming is caused by increases in this potent greenhouse gas.” Scientists then develop models and test their models against the actual measurements. Models that match the measurement are then the models that they adopt as tentatively true, until other data arrives and refines them. And what those models show, right now, is that we’re going to bake ourselves off this planet if we keep going this way.
That is not a liberal conspiracy. That is a model that fits the data. If there are other models that fit the data that show we are *not* going to bake ourselves off this planet, those models would be welcome. Unfortunately, no such models exist — just handwaving on the part of Preacher Bob and Oilman Steve and Politician Don about how science is a liberal conspiracy. So unless Preacher Bob and Oilman Steve and Politician Don can pull out some models that explain these temperatures we’re seeing that do *not* end up with us baked off the planet, they have no cause to claim “liberal conspiracy” — the data is the data, and the model is the model, and the way to refute them is to provide more accurate data and a model that better fits the data. Ranting about liberal conspiracies doesn’t do that, it just makes the ranter look like an idiot.
– Badtux the Science Penguin