Carbon what? Yes, I know it sounds strange. But fear not, go and download Tear Fund's excellent leaflet: http://www.tearfund.org/webdocs/Website/Churches/Carbon%20Fast.pdf (aimed at families).
Judging from the careless attitude of my own daughter to energy, I can't emphasise teaching green principles to the upcoming generation enough. Make sure your kids read though the leaflet and implement as much as you can etc.