Slate’s carbon challenge

Slate and Treehugger have teamed up to bring you the Carbon Challenge.… showing what you can do to reduce your carbon emissions, and help prove that we can have a greener lifestyle without having to go live in caves.

The eight-week challenge starts with evaluating your use of transportation, which accounts for about one-fifth of greenhouse-gas emissions worldwide.

Some things you can do… tweak your car for better mileage, walk when you can, choose the train over the airplane when it makes sense, and buy carbon offsets for those vacation flights. Complete the challenge, and you can win cool prizes like organic T-shirts.