The Green Revolution

Hainburg, Germany

Clarification In "The Greening of America" we wrote that by bicycling part of the way to work, Kelley Howell saved three fifths of a gallon of gasoline and avoided 15 pounds of carbon-dioxide pollution. Several readers questioned how that amount of gasoline, weighing less than four pounds, could have generated so much CO2. The extra mass comes from the oxygen in the air. In the engine, each atom of carbon in the gasoline molecule combines with two atoms of oxygen to make carbon dioxide. Additionally, in calculating pollution from automobiles, scientists take into account the carbon dioxide emitted in extracting, refining and transporting the petroleum.

© 2006