2. Leave your car at home. If you can stay off the road just two days a week, you'll reduce greenhouse gas emissions by an average of 1,590 pounds per year [source: EPA]. Combine your errands -- hit the post office, grocery store and shoe repair place in one trip. It will save you gas and time.
3. Walk or ride your bike to work, school and anywhere you can. You can reduce greenhouse gases while burning some calories and improving your health. If you can't walk or bike, use mass transit or carpool. Every car not on the road makes a difference.