Emergy-based comparative analysis of an ecological economy in the Yangtze River Delta

The Yangtze River Delta (YRD) has abundant regional advantages. Its rapid economic development plays an essential strategic role in China's overall growth; however, this place significantly pressurized on resources and the environment. Accordingly, this study developed an evaluation index and system of sustainable development for a green economic system based on the emergy theory. Moreover, comparative analyses were made according to the present ecological-socioeconomic systems of the YRD. The results indicated a large gap between the production efficiencies of the three provinces and a single city in the YRD. The highest emergy yield ratio was in Anhui Province, but the corresponding emergy yield per capita and emergy output density was the lowest; the environmental load ratios were all > 10, which is considered a high load; the sustainable development indices were all < 1, which represents a state of unsustainable development. According to the present research results, suggestions for the sustainable development of the YRD were put forth here. This research provides theoretical and methodological support for the sustainable development of an ecological economy in the YRD. It can serve as a decision-making reference for China to achieve the goal of carbon peak and carbon neutralization.