Journalist Pablo Päster of Salon.com extends the comparison further to a cross country trip, and comes to similar conclusions. (Differences in the math are attributable to the use of slightly varying assumptions regarding fuel usage and source equations.) Flying from San Francisco to Boston, for example, would generate some 1,300 kilograms of greenhouse gases per passenger each way, while driving would account for only 930 kilograms per vehicle. So again sharing the drive with one or more people would lower each individual’s carbon footprint from the experience accordingly.
But just because driving might be greener than flying doesn’t mean it always makes the most sense. With current high gas prices, it would cost far more in fuel to drive clear across the United States in a car than to fly non-stop coast-to-coast. And that’s not even factoring in the time spent on restaurants and hotels along the way. Those interested in figuring out driving fuel costs can consult AAA’s nifty online Fuel Cost Calculator, where you can enter your starting city and destination as well as the year, make and model of your car to get an accurate estimate of what filling ‘er up will cost between points A and B.
Once you’ve made your decision whether to drive or fly, consider purchasing carbon offsets to balance out the emissions you are generating with cash for renewable energy development. TerraPass, among others, makes it easy to calculate your carbon footprint based on how much you drive and fly (as well as home energy consumption), and then will sell you offsets accordingly. (Monies generated through carbon offsets fund alternative energy and other projects, such as wind farms, that will ultimately take a bite out of or eliminate greenhouse gas emissions).
Of course, an individual’s emissions from riding a bus (the ultimate carpool) or a train (many of which rely solely on electric power generated by their own motion) would be significantly lower. Paster adds that a cross-country train trip would generate about half the greenhouse gas emissions of driving a car. The only way to travel greener might be to bicycle or walk—but the trip is long enough as it is.
CONTACTS: Grist, www.grist.org, Salon, www.salon.com; AAA Fuel Cost Calculator, www.fuelcostcalculator.com; TerraPass, www.terrapass.com.
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