A complete and total scam, mind you, but at least it's voluntary.
Anyone flying out of SFO who wishes will be able to 'contribute' to a variety of 'certified' CO2-reduction programs by purchasing a 'carbon credit' based on the estimated 'carbon footprint' of the airline flight they are about to take at a kiosk in the airport.
Goofball winner of the week, but I'm all in for voluntary stupidity. If it actually generates a significant amount of cash, I'm jumping in the game with kiosks to 'help the children'. I promise I'll send all the money (after expenses, of course, including my 'fair' compensation as determined by me) to 'certified' child adoption & relief agencies.