Is not driving to work going to affect my carbon footprint? Let's see...
I drive 17 miles round trip at an average of 25 miles per gallon. That is .68 gallons per day (which at current Seattle pump prices would amount to $2.15/day) According to the Energy Information Administration, the number of gallons of gasoline is multiplied by 8.87 to get kg of CO2, which is then multiplied by 2.2046 to convert to pounds CO2.
For me, that is 13.3 lbs of CO2 per commute. If I commuted by car every working day (n=5 per week), I would contribute 1.75 tons of CO2 per year. If I decided to atone for my carbon sins, it would cost me $15-25 per year at CarbonNeutral, amounting to a paltry 3.5% of the actual gas prices.
Are biking and busing carbon neutral activities? (Anyone out there want to chime in?) If so, I save almost 2 tons of CO2 emissions by getting in exercise (bike) or reading time (bus).
But lets talk practicality. As part of Seattle's Way to Go commuting program, I have already started changing my driving behavior. As a grad student who works 7 days a week off of my school's main campus, I now drive alone to work rarely on workdays a week and 1 weekend day a week. My current total of 1-2 days a week is down from 6 days a week last spring. It is less convenient for me to bus on the weekend due to reduced service, but you might argue that I have more time on the weekends, so could bike. Either way, it takes away from weekend time I could spend with my sweetie.
I think the moral of this story is that my thriftiness is driving my behavior change more than the threat of carbon emissions. That $3/gallon can instigate such good behavior change in me helps forward my own notion that gas should increase to $10. (And that $$$ should go to state government, not Big Oil!)
How much does carbon footprint guilt impact your decisions about driving?