There is a lot of non-car-related greening is going on at the DIA, like recycling the deicing fluid used on airplane exteriors, managing storm water, and reducing hazardous waste generation by 75 percent between 2003 and 2005. The changes that affect the DIA's vehicle fleet include decreasing the overall amount of gasoline used in the fleet by one percent each year (which had better mean one percent off of today's baseline, not one percent lower each year based on the previous year, because that'd be a comparatively lame PR move). DIA hopes to achieve this through using more hybrids and CNG vehicles and to limit idling. It's a start, and I guess a hundred years is a long time to figure out the rest.
[Source: Denver International Airport]