A good way would be to share transport with others.
In this context we found a great site to cater for your needs :
Quoting from their website :
"Transportation is one of the biggest contributors of greenhouse emissions. If you look out at city traffic, or at a busy interstate, it's easy to see why. Millions of people drive great distances alone every day. It takes a lot of energy to push all those vehicles. And so many of those people are going the same way. Why not share the ride?
eRideShare puts the power of the Internet to work, connecting commuters or cross-country travelers going the same way. Put two people together in one car instead of separately in two cars, and the greenhouse emissions are cut in half. This is significant impact. You still get where you want to go, while saving plenty of cash. Maybe you'll even make a new friend or two."