San Francisco International Airport will soon be offering travelers the option to buy certified carbon offsets at airport kiosks, San Francisco Chronicle reports.

The airport commission has approved the trial program and SFO has invested $163,000. The airport is teaming up with 3Degrees, a San Francisco firm that sells renewable-energy and carbon-reduction investments.

In June, Denver International Airport halted plans to implement a carbon offset program due to minimal interest from vendors.

Details of the SFO program are still being worked out, but the general idea is that travelers would key in their destination at a kiosk and the computer would calculate the carbon footprint and the cost to offset the emissions.

Figures on 3Degree’s Web-based “carbon calculator” suggests that a two-hour trip uses about 1,000 pounds of CO2 per person and the offset cost would be about $4.

Mike McCarron, an airport spokesman told San Francisco Chronicle that the projects offered will be chosen by the mayor’s office, in conjunction with 3Degrees, from a list certified by the city’s Environment Department. A portion of each offset purchase would also go to the San Francisco Carbon Fund.

The Port Authority of New York and New Jersey will also start selling carbon offsets in early 2009.