With CAFE standards mandating MPG minimums in car fleets and new regulations for renewable fuel standards, it’s not surprising that other transportation providers are investing in becoming “green.”
Airports have made attempts at reducing CO2e emissions.  Dallas-Fort Worth encourages carpooling and has supported the use of taxis that run on compressed natural gas, a cleaner alternative to regular fuel.  Fort Lauderdale Hollywood uses a biodiesel petroleum fuel mix for their airport shuttles and trams, while airports in the UK have started composting yard waste and recycling runway concrete as pavement. Last September, San Francisco International Airport opened kiosks that allow individual travelers to purchase carbon credits to offset the emissions from their travels.
Airlines have started to become greener, too.  Delta Airlines features a recycling program on its planes which saves over 1,000 tons of waste from landfills annually, as well as an airplane carpet recycling program and a partnership with the Nature Conservancy to offset some of its consumers’ carbon emissions.  JetBlue offers organic food options in-flight and Southwest has a LEED certified terminal in Oakland, while the majority of airlines allow consumers to buy carbon offsets for their flights.  A fair number of airlines also have experimented with bio-fuels to reduce fossil fuel use.
While flying is often the least environmentally-friendly way to travel (besides driving alone in an SUV across the country), there are some options for how to compensate for the air pollution that may result from your next overseas vacation.