Spatio-temporal dynamic evolution of carbon emission intensity and the effectiveness of carbon emission reduction at county level based on nighttime light data

Accelerating carbon emission reduction is conducive to protecting the ecological security of the Qinghai-Tibet Plateau. Based on a case study of 41 counties in Qinghai Province, China, this study explored the characteristics regarding the spatio-temporal dynamic evolution of carbon emission intensity (CEI) by using the nonparametric kernel density estimation, spatial Markov chain, and spatial variogram model and used the corrective coefficient to examine the effectiveness of the decrease of CEI. The main conclusions are as follows: First, the CEI of most counties showed a decreasing trend, although a few counties exhibited unstable CEI increase through the study period. Second, county-level changes in CEI exhibited club convergence and spatial correlation, and the county-level spatial differences in CEI narrowed. Finally, the decrease of CEI in some counties was lower than the provincial average suggesting that, even at the provincial level, the principle of common but differentiated responsibility should be observed when promoting carbon emission reduction. This study provides several recommendations to promote the sustainable development of Qinghai Province.