of the system being modeled. Some models, such as the ones used in designing aircraft, are based on a very good understanding of the fundamental science involved. Even so, that doesn't negate the need for flight-testing. Many a test pilot has been surprised by design flaws that looked perfect on the drawing board.

Climate change is a hideously complex process and many if not all of the existing models are woefully lacking ("little" things like leaving out the effects of clouds and stuff like that). The Earth has undergone many warming and cooling cycles over the ages, many of them predating the Industrial Age by millions of years. There are two fundamental questions about the current global warming debate.

1. Is the Earth's climate warming? and
2. Is human activity responsible for it?

Regarding question number 1, there is pretty good scientific consensus that the Earth is warming, although some have provided some compelling evidence to the contrary. The second question is harder to answer simply because science doesn't have a good explanation for all of those pre-human global warming and cooling cycles. If we don't know what caused those cycles, how can anyone presume to say that the current one is primarily caused by human activity? That's simply faulty science, currently wearing the clothing of political dogma. Sorry, but the short answer is "we don't know enough yet to make an intelligent decision." Saying otherwise is an attempt to stifle scientific inquiry and is something I oppose wholeheartedly.