The really scary thing about climate change is the time lag. The warming we are experiencing today is the effects of the carbon emitted 20 years ago. If we stopped cold turkey right now we’d still get another 20 years of warming- but we won’t. So 20 years from now, we’re going to look around and go, gee, this is getting bad, but at that point we will be committed already to another 20 years of warming after that.