The impact of technology-environmental innovation on CO2 emissions in China's transportation sector.

Along with the development of urbanization and informationization, an increasing attention has been attracted to CO2 emissions of China's transportation sector and its influencing factors. Such researches mainly utilize single indicator or two indicators to represent technology process. This research aims to verify the influence of technology-environmental innovation indicator system on CO2 emissions of China's transportation sector by decoupling elasticity and econometric model. We firstly recognize the decoupling status of CO2 emissions of China's transportation sector from social economic development and aggregate China's 30 provinces into two groups according to the varied decoupling status, namely expansive coupling and weak decoupling groups. Then, we develop a relatively comprehensive technology-environmental innovation indicator system to measure technology process. Finally, the multi-region comparison of emission drivers is studied among overall China and the two groups. The result shows that the decoupling elasticity of China's transportation has experienced an evolution process trending to desired development status and all the provinces have experienced expansive coupling and weak decoupling from 2001 to 2016, except Qinghai. Innovation performance indicators exert most important influence on the CO2 emissions of transportation sector. Finally, the influences of technology-environmental innovation indicators are similar across groups with different magnitude, suggesting that common but differentiated strategies should be provided when mitigating CO2 emissions with technology process. Graphical abstract.