Coal production efficiency and land destruction in China's coal mining industry

China is the world's largest coal producer and coal consumer. While coal still plays a vital role in China's energy structure, new policy directions propose a 15% reduction in coal consumption by 2040 compared with 2016 as coal exploitation and use has caused extreme environmental pollution and land surface damage. Previous coal energy efficiency research has mainly been static analyses focused on coal-fired power plant efficiencies, carbon dioxide efficiencies, regional coal consumption and coal energy efficiencies, or coal mine area or enterprise production efficiencies, with few studies having included land destruction or other environmental problems. However, if a time factor is not included, it is generally impossible to accurately estimate the real changes in coal production efficiencies and land destruction. To overcome these deficiencies, this paper applied a modified dynamic DEA SBM model to evaluate the coal production efficiencies and land damage in 24 Chinese provinces from 2011 to 2016, from which it was found: (1) seven provinces were efficient in all six years and needed no further improvement; (2) the coal industry labor force, fixed assets, and coal production efficiencies dropped significantly, but the land damage was ambiguous; (3) the land loss efficiency analyses found that Shanxi, Inner Mongolia, Fujian, Jiangxi, Shandong, Guizhou, and Shaanxi had no need for further improvements; however, the land loss efficiency differences were large and there were improvements needed in 17 provinces, with the need for improvements expanding in 15 of these provinces; (4) even though Inner Mongolia, Shaanxi, and Shanxi had the largest coal mining operations, the need for land damage improvements was 0; however, Beijing and Guangxi had the smallest mining quantities, but the greatest need for land damage improvements..