An idea: ecological GDA (Guideline Daily Amounts). GDA helps make healthy decisions about the food we buy. Why not have a similar system to help estimate and reduce our ecological footprint – the ecoGDA? CO2 here is just an example, this concept could be extended to any relevant components of our consumption. Saving the environment is difficult enough without having to calculate the affect of your every move, so why not make that easier? What do you think? All comments are appreciated.