Evaluation of China's coal resource energy carbon emission efficiency in the whole life cycle

Based on the LCA, the carbon emission estimation model of coal resources in the development, conversion and utilization stages was constructed, the dynamic network SBM model was used to calculate the comprehensive energy carbon emission efficiency, period energy carbon emission efficiency and phase energy carbon emission efficiency of coal resources in China's 25provinces from 2007 to 2019. The results showed that the comprehensive energy carbon emission efficiency level of China's coal resources was distributed in a U shape, with the highest in the east, the second in the west, and the lowest in the middle. There was a large room for improvement in the carbon emission efficiency level of coal resources and energy, the average value of comprehensive energy carbon emission efficiency from 2007 to 2019 was only 0.4726. There were significant regional differences in energy carbon emission efficiency during the coal resource period in China, and the regions with higher efficiency levels were mainly concentrated in East China and Central South China; From the stage energy carbon emission efficiency analysis, it can be found that only the stage 1and stage 3energy carbon emission efficiency of the three provinces of Beijing, Jiangsu and Qinghai at an effective level. The remaining provinces and other stages have efficiency losses, especially stage 2efficiency losses serious. During the study period, the energy carbon emission efficiency of stage 3 showed a peak-like fluctuating upward trend as a whole. The comparison of the energy carbon emission efficiency measured by the DNSBM and NSBM models found that the NSBM model would underestimate the comprehensive energy carbon emission efficiency level of coal resources. © 2022, Editorial Board of China Environmental Science. All right reserved.