Actually, what you say does not follow from that logic. The point was whether we're adding to it or not. To me it's inescapable that we are. But that's the irony, isn't it? We could cut our emissions to zero and be done in by a bunch of volcanos. Or they could go dormant on their own and we could continue the way we are and do it to ourselves without help. We could say that we'll get hit with a meteor anyway at some point so why treat the place nice? Because maybe you won't get hit. Welcome to the uncertainties of life on Earth. Natural processes have been going on, heating and cooling have gone on, tremendous calamities have happened. What hasn't been going on is mankind's contribution on top of it. If there's a fire already burning - do you throw wood on it if you're already uncomfortable from the heat?