In the U.S., more than 30 percent of CO2 emissions come from transportation, mostly from personal cars and trucks. Each gallon of gasoline saved keeps 9 kilograms (20 pounds) of CO2 out of the air.
Various measures that one can take to drive less include:
- Biking - In Copenhagen, Denmark, 36 percent of the population commutes to work by bike, saving 90,000 tons of CO2 emissions per year compared to driving the same distance by car.
- Combining errands
- Taking mass transit - By riding public transportation instead of driving a car, one person saves on average 2.2 metric tons of CO2 per year.
Driving fuel-efficient cars
A hybrid driven 24,000 kilometers (15,000 miles) a year that gets 19 km/liter (45 mpg) emits about 4.0 metric tons of CO2 each year. An SUV that gets 8.5 km/liter (20 mpg) emits 10.3 metric tons of CO2 each year.
Maintaining your car
Soft tires waste gas--enough to emit an extra 113 kilograms (250 pounds) of CO2 per car each year.
Clean air filters save 360 kilograms (800 pounds) of CO2 emissions per year.
Better driving habits mean better fuel economy and fewer CO2 emissions. Every mile an hour over 60 lowers fuel economy by about 1 percent.
Using cruise control on the highway
Avoiding quick starts and stops
Aggressive highway driving can lower fuel economy by about 30 percent.
Staying within the speed limit
Idling burns gas, and every gallon burned emits about 9 kilograms (20 pounds) of CO2. Plus, idling gets zero miles per gallon.
Carrying an extra 45 kilograms (100 pounds) of cargo can cut mileage by 2 percent.
Every gallon of jet fuel burned emits 9.5 kilograms (21 pounds) of CO2. An average flight from New York to Washington emits about 80 kilograms (176 pounds) of CO2 per passenger.
Extra weight means more fuel burned and more emissions.
Taking direct flights when possible
Idling, circling, takeoffs and landings burn a big chunk of fuel on any flight.
Using other types of transportation
Electric commuter trains emit about 25 percent less CO2 per passenger-mile compared to airplanes.