Anonymous public comment

Carbon Dioxide is utterly mischaracterized as a "pollutant": it is as essential to life on Earth as is oxygen. No reasonable restriction on CO2 emissions from mobile sources in the US can possibly be expected to materially reduce the CO2 concentration in the troposphere, since the contribution of those sources to total Global CO2 loading is infinitesimal in proportion to the economic and health benefits realized from effective surface transport. I speak as a retired professional having spent a career developing powertrain controls and innovations which have contributed in a small way to the reduction of ICE (internal combustion engine) system emissions of hydrocarbons, oxides of nitrogen, and carbon monoxide (a true and toxic pollutant, as opposed to the dioxide). The mission of the EPA is to protect human health. CO2 reduction from US mobile sources cannot materially improve human health. Elimination of all CO2 from all sources, while not feasible, would result in death of all mammals, an outcome clearly out of scope for the agency. Thank you for the opportunity to comment.