Global warming, climate change, whatever label you want to put on it -- there are three separate empirical questions involved:
1. Is the climate changing? Climatology is a science, though a relatively young one. And short-term (e.g., in 200 years or less), its about as exact as weather science is in the long run (more than a week). Things do change in the long term, however, so it could well be on a path of change to an ice age or icecap melting or whatever. I'm willing to give the self-called experts of the benefit of the doubt on the long-term climate question, based solely on the fact that its pretty clear we have had changes in axial tilt, major meteorite strikes, ice ages, and the like in the past and there is no reason to think we might not have them again.
2. Is the climate changing because of human action (industrialization, pollution, etc.)? This is a far bigger claim than #1.
You can do a lot of things with computer-based simulation now -- in many ways Monte Carlo and other simulation methods are far superior to the "traditional" statistics most people were exposed to if they took one or more statistics classes in college (and, with most disciplines, even in grad school prior to 1990s). The expense of traditional sampling methods (in surveys, in labs, double blind or whatever) means one has to make pretty major intellectual leaps of faith to get from evidence on correlation (A and B happening at the same time) to an inference about causation (A happening because of š.
If you were raised on standard ideas of probability and sampling, simulation can look like "pseudo-science" and science fiction. But there is no doubt that in the hands of top scientists, simulation can yield amazing and worthy inferences about questions of causation that wouldn't be possible otherwise. Without simulation, Fermi, Ulam, and the rest of the Manhattan project would have had to have tens of thousands of atomic explosions like those in New Mexico and the South Pacific before they could have had a workable bomb, for example.
Does that mean the scientific simulations at the heart of the global warming "evidence" are sufficient to prove the point their advocates claim? Not hardly. Nobels notwithstanding, Al Gore and his "scientist" friends are nowhere near the intellectual level of Oppenheimer and Teller, much less of Fermi, Ulam, and company. And climate science is far from as developed in its theory and sophistication as physics had been long before 1945.
Climate change science is closer to where physics was at the time of Copernicus, Galileo, Newton and , still breaking away from the science of Ptolemaic epicycles and the science of alchemy (Newton himself was still a practitioner of the latter).
We know an amazing amount of stuff about climate today that we never used to. But compared to what we don't know, it's trivial.
And even if, somehow, today's pioneers of climate science are getting the climate change because of human action hypothesis correct, there's the third question to deal with ...
3. How do we stop/slow/do anything meaningful about the human-caused changed? Here, to my mind, is where the real hubris of these "scientists" (and their non-scientist followers) shows up. There's a big distance between being able to explain what has happened and being able to manipulate things to get them to happen in a particular way. Newton understood gravity better than the climate people understand CO2. Do we have any real clue how to stop apples from falling down and make them fall up?
We can make them go up (put them on top of a rocket or a giant explosive device). But have we figured out how to make them even their seeds go up cheaply enough to make it economical to feed people with space-grown fruit?
I believe in science. In general, we're better off paying attention to the evidence it provides than ignoring it. But we're even better off -- far better off -- when we pay attention to it AND recognize the limitations of that evidence. Because when we don't do so, we are being wilfully ignorant and prideful. Far more harm is done by this unsupported faith in science and its methods than benefit is generated.
And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God.
Romans 12:2 (NKJV)