Urbandictionary.com's word of the day is Carbon Guilt (yeah, I know it's two words). It is defined as
The feeling of guilt for using too much carbon,
e.g. too much air travel,
driving to the corner shop in the car, etc
'Man, I have to fly to Zurich for the second time this month'
'Whoa, you must have some major carbon guilt over that'
It's official, environmentalism has become mainstream.