A couple of other basic facts: Humans are adding gases to the atmosphere that affect Earth's radiation budget at an unprecedented rate (which makes modeling the effects of such additions very uncertain), and the Earth's climate has warmed by about 0.6 degrees C in the past century, with some observable effects on climate and ecological systems.
Unprecedented? This implies that we know what rates of emission occured in all previous eras and that those emission rates were all less than today's rate. We don't and can't know that sort of thing, since the means for accurately extrapolating such data are unavailable. We can only theorize.
The claim that the earth's climate has warmed 0.6 degrees C in that past century is absurd, cogitator. To qualify as scientific, the methods used to measure climate temperature in 1902 would have had to be the same as those used today (a clear "apples and oranges" problem). Either that, or the method for extrapolating that information would have to be far more reliable than it actually is. The problems inherent in making such a measurement of "overall climate temperature" are daunting, to say the least -- starting with basic definitions.
To posit "observable effects" of this undemonstrated "climate warming" suggests that we have established a cause for those effects. But nobody has, at least, not scientifically.
Far from being "basic facts," it's all supposition. And this is the basis on which the globaloney spouters want to dismantle our economy.