The effect of urbanization on carbon dioxide emissions efficiency in the Yangtze River Delta, China

Cities have been one of the most important areas of CO₂ emissions. It is increasingly important to research the effect of urbanization on CO₂ emissions, especially in large emerging and developing economies, due to the indispensable need for understanding the effect of urbanization on CO₂ emissions, evaluating carbon reduction tasks and providing the scientific basis for low-carbon urbanization. Utilizing a balanced panel dataset in the Yangtze River Delta (YRD), China, during the period of 2000–2010, this paper employed data envelopment analysis (DEA) window analysis and a spatial lag panel Tobit model to investigate the effect of urbanization on CO₂ emissions efficiency (the ratio of the target CO₂ emissions to the actual CO₂ emissions). The results show that the average CO₂ emissions efficiency was 0.959 in 2010, and CO₂ emissions efficiency ranged from 0.816 to 1 and exhibited spatial clustering in the region. The larger potential of CO₂ emissions reduction appeared in Zhenjiang and Yangzhou, indicating that more CO₂ emissions reduction tasks should be allocated to these two cities. Urbanization has negative effects on improving CO₂ emissions efficiency, and there is a U-curve relation between CO₂ emissions efficiency and urbanization, indicating that CO₂ emissions efficiency decreases at the early stage of urbanization, then increases when urbanization reach a high level. There is spatial spillover effect among the prefecture-level cities, suggesting that different prefecture-level governments should coordinate with each other to improve CO₂ emissions efficiency in the whole area. Gross domestic product (GDP) per capita also plays a markedly positive role in improving CO₂ emissions efficiency. This research highlights the effect of urbanization on CO₂ emissions efficiency and the importance of improving CO₂ emissions efficiency in developing countries.