This service let's oyu buy carbon credits to off set the carbon output of your vehicle:
This is and admirable and cool thing, but I have to wonder about the effectiveness of it. The Chicago Carbon Exchange releases a set number of carbon certificates a year. Each certificate represents an about of carbon exhaust. Companies voluntarily sign up and enter contracts where they have to buy credits each year and are limited to the amount of certificates released that year.
In theory, I think this is a cool thing. In practice, given that membership is voluntary, only companies already willing to be green are doing it, and the worst environmental offenders just laugh at joining
I suspect the CCX, at least in the U.S., will be lame duck until states or the federal government makes membership mandatory for doing business in that state or in the nation as a whole.