SciAm's Error
It appears SciAm overstated human emmisions greatly. The total listed by the BBC (FOSSIL FUEL EMISSIONS) is around 6 billion tons while a recent CNN article (Bad economy helps clear the air) lists 1.8 billion (US alone I think) .
Sciam was off by a greater magnitude, but Rushites more misleading because humans do dominate by far.
Regards,
Mark