The natural and social properties of CO2 emission intensity

The formation of CO2 emission intensity reflects two properties: The natural property reveals CO2 emission intensity as being derived from energy intensity. The social property reveals the impact of energy and environment policy on the fuel mix, and further affects the numerical value of the index of CO2 emissions/total primary energy supply (TPES). This paper emphasizes that understanding the above two properties can help us in making energy and environmental policy for achieving the Kyoto Protocol and other environmental targets.