Modeling carbon emission performance under a new joint production technology with energy input

The nonparametric data envelopment analysis (DEA) methodology has gained much popularity in assessing carbon emission performance within a joint production framework with energy inputs and CO2 emissions. The majority of existing studies, however, neglected the interlinkage between energy inputs and CO2 emissions in their analytical frameworks, which may distort the modeling results. To address this issue, we invoked the weak disposability assumption for both (fossil) energy inputs and CO2 emissions, and developed a new joint production technology that was found in line with the material balance principle and simultaneously allowed for the flexibility of emission abatement options. Built upon the production technology, we developed two indexes to measure carbon emission performance, and proposed a decomposition model to quantify the roles of different options in abating CO2 emissions. We also applied the proposed models to study the carbon emission performance of the world's top 25 CO2 emitters. It was found that carbon emission performance varied across different emitters and different abatement options. Energy efficiency improvement and energy structure adjustment were not of equal importance in pursuing the minimum CO2 emissions.