Environmental Kuznet's curve China 4 Kuznets curve 4 Environmental Kuznets Curve 3 spatiotemporal analysis 3 Carbon 2 Carbon dioxide 2 Carbon emissions 2 Commerce 2 Economic and social effects 2 Economics 2 Emission control 2 Gross Domestic Product 2 Agglomeration 1 Bio-energy 1 CO 2 emission 1 Carbon dioxide emissions 1 Carbon emission 1 Carbon footprint 1 Case-studies 1 Chinese cities 1 Coupling curve 1 Cross-border 1 Decision support systems 1 Developing countries 1 EKC 1 Eco-environment 1 Eco-environmental quality 1 Eco-environments 1 Efficiency 1