Broke, you're one of the good examples of why there is a "consensus" among "scientists" that AGW is real, and it's just a question of how much. And you're also an excellent example of why that consensus should not exist, how scientists who took the vow of empiricism seriously should not be part of that herd. (And I don't mean to be too critical; I understand the temptation, as one who happens to be an expert in very similar fields.)
Here's the problem. As someone who knows the molecular physics well, you can see the components that go into the AGW hypothesis. CO2 has an infrared cross-section of foo, and the atmospheric concentration of the stuff atop Mauna Kea has increased from bar to baz since 1960, and you get CO2 from burning any hydrocarbon in O2, so...well, there you go. Plain as a pikestaff. Hitch these facts together with a little logic, and you have a hypothesis of AGW.
That's actually fine as far as it goes. But what you should bear in mind is the key distinction we always teach youngsters between a hypothesis and a decent theory: empirical verification. It's simply not enough to say oh, A follows logically from B. That's Aristotelian "science," the way the Greeks deduced that there were four Elements (fire, water, earth, air) from which everything was made. The same way 18th century chemists came up with the theory of phlogiston to explain combustion. The same reason Michelson expected to find an ether drift.
No, it only becomes plausible theory when you actually run the experiment, and show that B produces A, every time, and not B produces not A, every time. Unless and until you do that, you merely have a plausible speculation.
As you know, the big problem with climate "science" -- I'm inclined to call it "climate studies" myself -- is that it is impossible to do the relevant experiments. We can't take a planet and jack up its CO2, then see whether the climate changes relative to some identical planet where we hold the CO2 constant. In the absence of that kind of experimental test, you do not have an empirical science. Yes, the components of climate studies -- molecular physics, atmospheric chemistry, complex systems simulations -- are all legitimate sciences, because you can do the experiments that directly confirm or contradict the theories. But when you assemble all these pieces into predictions of climate -- of what happens to the whole damn planet, over centuries -- then, alas, it stops being a science, because the experiments can't be done. (It's like theories of history: in the same way, we can't run history over again, have Truman make a different decision, and see whether lives were on balance lost or saved by the atomic bombing of Hiroshima. This is why history is not an empirical science.)
Good engineers recognize this problem. Even if every part of your machine has been proved to work as you expect, that doesn't mean the assembled whole is going to work as you think it will. The whole is always more than the sum of its parts, and can surprise you.
You're an expert on one component of climate studies. Excellent. The constructions seems plausible to you. Fair enough. But your experience as a scientist should convince you (unless you are so young you have not experienced any surprising failures of your ideas) that unless it can be subjected to the crucible of experimental proof, the most convincing argument in the world is merely that -- an argument -- and does not rise to the level of empirical science.
