We are responsible for global warming. Formally responsible. Whether we caused it or not. Whether we can ever prove that we caused it or not. We are responsible for global warming simply because we are sentient. No more elaborate reason is required.
If you believe a more elaborate reason is required, consider the following examples.
When you see a child about to be hit by a car, do you say “I'm not directly responsible for her death, so I won't help her”? When your house is burning down, do you say “Well, I didn't start the fire, so I'm not responsible for putting it out”?
The big difference is that unlike the girl and the house, you can't see climate. Climate isn't weather. You can see weather. But you can't see climate, in the same way that you can't see momentum but you can see velocity. Climate can just about be seen by very powerful computers using terabytes of RAM. So just because it snowed near you recently it doesn't mean that global warming isn't happening.
This is tough: taking responsibility for something you can't see. But it's no tougher than taking responsibility for say, not killing—you don't have to come up with a reason, you just do it, and figure out why later. That's why it's called an ethical decision. It doesn't have to be proved or justified. You just do it. (This doesn't mean that your act is unconscious. I'm far from saying just do what you feel is right. It means that you act spontaneously and consciously. See below.)
Global warming denial, funnily enough, depends upon and contributes to an idea of Nature that isn't that different from the child in the street or the burning house. It's different from me, it's over there—in some fundamental way, it's not my concern.
Part of assuming direct responsibility for global warming will be letting go of the idea of Nature, an ideological barrier to realizing how everything is interconnected.
Feel free to cut and paste and post on every global warming denial page you find.
Global warming deniers currently have us in a headlock. It's like a man with a gun to someone's head, saying “Give me a good reason not to shoot this guy.” Do you give a good reason (It's right, it feels good, there's a symbiotic web in which we are immersed and you are damaging it, you are upsetting a natural balance...) or, assuming you are strong enough, do you just grab the gun?
All the reasons in the world aren't reason enough, from a certain point of view. (This is why Kierkegaard says the ethical position is an upgrade from the aesthetic one—in the aesthetic one, you do things because they feel nice or because they look nice. In the ethical one, niceness—or even rational soundness, which is perhaps also a kind of aesthetic order—doesn't matter.)
One implication of my argument is that it's possible to be fully conscious and totally spontaneous, at the same time and for the same reasons. This is why I profoundly disagree with Gregory Bateson, who asserts that the only good decisions are unconscious ones (sounds sinisterly like “The only good woman is a dead one”). It has to do with our very different interpretations of a key moment in Coleridge's poem The Rime of the Ancient Mariner. More on this later.