But the model of gravity is extremely murky. No one knows exactly how it works, how it travels, etc. Does it travel by wave? By particle (affectionately known as gravitons)? Both? Or something else? Does it travel at the speed of light ala relativity? Faster? Slower? Is it instantaneous ala Newton? In fact, some argue that there is no such thing as gravity, that it's actually a phenomenon of the curvature of space-time. I don't think gravity is as well proven or understood as you think it is.
That's the difference between chemistry and physics. How the experiments work and how you prove things is a little different and the models are not as concrete, but the climate models are not as concrete either. But how C02 works in the atmosphere is not as well understood as how a feather and a rock fall. The actual mechanism is not understood, but we can predict what it will do. But CO2? NOt enough evidence and the models aren't as all encompassing. Yet.
Yes I'm familar with Collapse. The Mayans are a perfect example of what the author discusses. But then there are more civilizations that were destroyed by changes in their enviornment that they had nothing to do with. There are also others who made the right changes in their enviornment and flourished. And then came a change they could do nothing about and fell.
What I am saying is that if we did dismantle our industrial civilization it wouldn't make a damn bit of difference! It would still happen. You pick nits with C02 and gravity all you want but rocks still fall at the same rate and the atmosphere will change whether we are an industrial or pre-industrial civilization.