Want to know how much of an impact your flight is having on the environment?
A tech firm, Brighter Planet, developed an app, Careplane, that uploads into your browser. So when you search for flights online, the app calculates pollution from each flight based on historic flight data, like plane weight, the average percentage of filled seats and fuel efficiency. The app will deliver the total number of pounds of greenhouse gases produced by the flight you select.
So, a nonstop flight from Los Angeles to the San Jose airport on a regional jet generates 618 pounds of greenhouse gases. While Los Angeles to San Francisco on a larger airline will create 730 pounds of pollution, according to an article in the Los Angeles Times.
I'm not sure how much pollution plays a factor in which flight you choose, but its an interesting idea.