A method for the development or generation of pollution credits by the substitution of lower global warming potential (GWP) mixtures of halogenated hydrocarbons or mixtures of halogenated hydrocarbons with CO2 for fluorocarbons or fluorocarbon-containing compositions of higher GWP, such as for perfluorocarbon compounds (PFC's), hydrofluorocarbon compounds (HFC's), chlorofluorocarbons (CFC's), hydrochlorofluorocarbon compounds (HCFC's), and compositions thereof, in compositions and processes employing the higher GWP compounds, and receive allocation of pollution credits for such substitution.