Wow...
I just don't even know where to start with that. You're a bright guy, so I know you are consciously and deliberately missing the point.
Your argument *seems* to be (correct me if I'm wrong) that as long as we don't move outside the parameters within which life is viable, it's ok for humanity to alter the environment all its little heart desires. SinceCO2 levels have been much higher in the past, you seem to claim, we needn't concern ourselves with a CO2 rise today (regardless, I assume, of the cause for that rise).
Am I getting it?