If you’ve calculated your ecological footprint (a good thing to do every Earthday), you know that air travel uses a lot of energy and creates a lot of pollution. A company called Terrapass (which I just learned about through the web site livingwithed, which I learned about through noimpactman–it’s an eco-surfing day) will calculate the carbon emissions of a trip and let you offset your pollution through investing in alternative energy.

For instance, my trip to New York in June for the American Ethical Union assembly will add 796 pounds of CO2 to our atmosphere. For $9.95, Terrapass will invest in a comparable amount of alternative energy production (such as by investing in wind farms and solar arrays). Terrapass is independently audited to ensure that my $9.95 will actually be invested in alternative energy and not, say, the vice fund.

If you’re a savvy-investor type, you could invest directly in alternative energy every year to offset your pollution and help us all move toward a sustainable future. For those of us less savvy, Terrapass seems like a good idea.