I really do appreciate how visible Terrapass is and how it's been partnering with organizations like Expedia.com and Enterprise rental cars. I think any work towards offsetting carbon emissions and making it easy and accessible is really fantastic. I always hesitate with for-profit companies, though, because I never know how honest their intentions are. Also, I believe there are other, more transparent carbon offsetting options.
Regardless, the fact that Terrapass is so accessible and so user-friendly, not to mention the fact that it offers so many offset options (driving, flying, home, college), warrants the 4-star rating. Because, really, any time there's a company working to make this world better, they deserve the credit.
Shayne B.'s keywords: carbon offsets, carbon emissions, driving, flying