The question is does man have any measureable affect on climate, which is impossible to measure because it is below the natural variability of the whole climate system. Man's contribution is a lugnut on the spare tire on the vehicle of global cliamate.
Besides that Al's Still Sore, the great global gasbag, could use a good smearing, he'd just be getting back some of what he has dished out over the years... Just ask Dr. Roger Revelle, the man that A$$ claims changed his life by teaching him about CO2, only A$$ misunderstood, and when Dr. Revelle called him on it, A$$ smeared him. Or ask S. Fred Singer, or William Happer, or Hugh Ellsaesser. Just a few, of a lifetime of such smears, suppressions, and cohersions.
Bring on the smears, A$$ is owed a million more.