Replace three frequently used light bulbs with compact fluorescent bulbs - reduce your carbon footprint by 450 pounds a year.
Carpool, commute by bicycle, use Public Transportation, or drive a fuel-efficient car - reduce your carbon footprint by 1 pound for every mile you do not drive.
Keep your tires properly inflated and get better gas mileage - reduce your carbon footprint another 20 pounds for each gallon of gas saved.