WC Archive

If you take one of the various ecological footprint tests we've linked to over the months here at WorldChanging, you'll find that one of the nastier things you can do to your score is admit to frequent air travel. Airliners spew emissions in the upper troposphere, near the transition to the stratosphere; according to the UK's Royal Commission on Environmental Pollution (PDF), this is a particularly critical part of the atmosphere when it comes to trapping greenhouse gasses. Jet aircraft put a lot of carbon into the atmosphere; air travel could account for 75% of the UK's greenhouse gas emissions by the middle of this century.

But what if the carbon you put into the air had just been pulled out of it? The "carbon neutral" approach -- which doesn't make things cleaner, but doesn't make them worse, either -- underlies aggressive research into the use of biofuels for aircraft. And according to New Scientist, a breakthrough may well be at hand. The stumbling block for the use of biofuels has been their relatively high freezing temperature compared to petroleum, an issue at the ultra-low temperatures of the upper atmosphere. A Purdue University team has figured out how to greatly reduce the freezing temperature of fuel made from soy, and is now testing it in a mix with traditional jet fuel.

Not quite carbon neutral yet, but it's a start. Air travel has to be made cleaner. As a great proponent of interenational travel, I'm not eager to have to choose between the planet and the world.

(Image: CNN)