In the following video, Motley Fool financial analysts Matt Koppenheffer and David Hanson discuss a pretty interesting move Citigroup (NYSE:C) is making at the moment, to help reduce our worldwide carbon footprint. Matt tells us about Citigroup's cooperative effort with a bank in Mongolia to reduce the amount of carbon being used there, and how it is transferring those saved carbon credits to environmentally conscious consumers. David then discusses why this is good not only for the planet, but also for investors.