Gas mileage

To and from school twice-~50 miles., Misc. food and recreation-~20 miles. My gas mileage is 30-35 miles per gallon. Approxiamately ~18,000 miles per year. The carbon foot print of my car is 7.7 per year and using this number it is .021 per day. I could ride my bike more than I drive, but I would not be on time to places, or I would not have as much time to manage my day, which would complicate things. On the other hand my car gets very good gas mileage in comparison to all other fuel driven cars around, which offsets my usage a good bit. In some cases I get double or more than double the gas mileage that others get.