Multi-dimensional and Comprehensive Measurement Study on Low-carbon Development of China's Megaciti

Taking China's megacities as the research unit, this paper selected 18 indexes from five dimensions: low-carbon economy, low-carbon development, low-carbon life, low-carbon environment and low-carbon energy consumption, and constructed a low-carbon development evaluation system. Combined with data envelopment analysis, a multi-dimensional and comprehensive measurement evaluation of the low-carbon development level of China's megacities was also conducted. The results showed that: (1) The average comprehensive scores of 16 Chinese megacities in 2005, 2010 and 2015 were 0. 0892, 0. 0854 and 0. 863, respectively. The low carbon development level showed a trend of first decreasing and then rising. (2) Spatially, the low-carbon development level of eastern cities was generally high, but the internal differences were large, and the development of the Beijing-Tianjin-Hebei region was uneven, with Beijing having a higher level of development and Tianjin having a lower level of development. The development index of the western region was generally low, and the scores of Chongqing, Chengdu and Xi'an were all at low and lower levels. (3) From 2005 to 2015, the development of low-carbon economy increased steadily, of which the development level of the eastern region was significantly improved. The level of low-carbon development had declined. The level of low-carbon living was showing a significant downward trend. The development of a low-carbon environment had improved. The development of low-carbon energy consumption was basically stable, but the pattern had changed slightly. (4) From 2005 to 2015, the overall level of the comprehensive performance of national low-carbon development was not high, which reached 75. 3% of the optimal level, and there was a problem of low input-output efficiency. The pure technical efficiency of low-carbon development had only reached 88. 3% of the optimal level, which had great development potential. The scale efficiency of low-carbon development had reached 90% of the optimal level, and there was room for improvement.