When it comes to the environment and your travel, sometimes a mile is a mile is a mile.

Let's start with this stat: planes are roughly comparable to cars in fuel consumption per passenger mile, at least with respect to carbon dioxide output. It makes for an easy comparison; a 60-hour cross-country car trip burns up about the same amount of fuel per passenger, and has the same "carbon footprint," as a five-hour cross-country flight.

I don't think a traveler has to be a member of Greenpeace to reach the end of a 3,000-mile drive and think "Whoa, I burned up some fuel on this trip." However, the same person might step off a plane after 4.5 hours eastbound from Los Angeles to New York and not ponder even for aninstant the resultant fuel consumption, greenhouse gas emissions or carbon footprint of their trip. How bad can the damage be when you barely had time to fall asleep?

The truth is that air travel does even more damage than you'd imagine -- so much that many travelers are looking into ways to neutralize the carbon emissions from their flights. A whole host of companies have sprung up to help travelers go "carbon neutral," an increasingly popular term that was

The Boeing Dreamliner promises to be one of the least polluting aircraft ever used for commercial flights, and should go some way to answer criticisms of aviation's environmental record.

The Dreamliner represents a continuing trend towards lower carbon emissions Photo: GETTY

The Boeing Dreamliner 787, which is due to make its first commercial flight later this year with All Nippon Airways, is expected to change air travel in more ways than one. Not only should it offer passengers greater comfort, but it will also be among the least polluting aircraft ever to enter commercial operation.

The new plane will be quieter and use 20 per cent less fuel than aircraft of equivalent size, thanks to greater engine efficiency, the use of lighter composite materials and improved aerodynamics.