Exploring the nexuses between carbon dioxide emissions, material footprints and human development: An empirical study of 151 countries

In order to achieve the Sustainable Development Goals, it is necessary to actively promote a coordinated and balanced relationship between carbon dioxide emissions (CO 2 e), material footprints (MF) and human development, based on the economic and social development stages of different countries and their material resource endowments. However, the existing research results lack cross-country comparisons and overly focus on the single conclusion of quantifying decoupling while ignoring the impact of coupling coordination nexus. Thus, this study comprehensively evaluated the nexus between CO 2 e, MF, and human development index (HDI) in 151 countries from 1990 to 2019 based on the modified coupling coordination degree model and the improved decoupling index model. The results show that, both the global MF per capita and HDI have maintained an increasing trend, and the MF per capita has been increasing significantly faster than the HDI. The trend of CO 2 e per capita is slowly dropping, with very high HDI countries being the main contributors. Besides, global regional differences in CO 2 e per capita and MF per capita are still expanding. Worldwide differences in per unit of CO 2 e and per unit of MF for HDI variation are narrowing. Furtherly, there is a more general but short-lived trend of absolute decoupling for very high HDI and low HDI countries, while medium HDI countries show a significant trend of coupling. By combining the endowment characteristics of some typical countries, it can be observed that the net fossil energy importing countries with higher HDI have high degree of coupling coordination, but gradually evolve towards the state of relative decoupling. There is still a significant trend of recoupling between the MF and HDI in the net fossil energy exporting countries with higher HDI, but CO 2 e is gradually evolving towards decoupling. The coupling coordination state is deepening in some low HDI countries. Due to the huge differences in national endowment characteristics and development stages, targeted energy conservation and emission reduction strategies are important for achieving coordinated development between CO 2 e, MF and HDI.