Burning 1 gallon of gas emits almost 20 pounds of CO2
"Abandoning your wheels is one of the greatest things you can do to shrink your collegiate environmental footprint, since burning a gallon of gas emits almost 20 pounds of carbon dioxide. That's 600 pounds of CO2 in just four 200-mile trips home and back" (page 15).
Bob Schildgen, "Ask Mr. Green: Be Cool at School," Sierra Magazine, 98, no. 5 (2013), 15.