Multi-dimensional decoupling analysis in the context of energy use: Dynamic well-being, resource, and impact decoupling relationships in China

Energy use and associated greenhouse gas (GHG) emissions decoupled from economic and human development is critical in achieving sustainable development. Resource and impact decoupling studies expanded to include well-being decoupling in the context of energy use. Additionally, multiple energy use and associated GHG measurements are developed and used in decoupling research. However, there are limited discussions about meanings of decoupling status when using different parameters, as well as exploring similarities behind the status across multiple decoupling relationships. This research first developed an overarching framework to evaluate decoupling relationships using various energy and GHG measurements and comprehensively identified the status of three decoupling relationships at the subnational level in China from 2000 to 2019 using the Tapio model. It also innovatively combined the Tapio decoupling model and decision tree analysis to reveal socio-economic features shared by provinces with the same status. It found that although weak resource decoupling and carbon impact decoupling from energy use from 2000 to 2019 are dominant, most provinces experienced negative decoupling between energy use and human development and weak decoupling between GHG emissions and HDI. When further evaluating the spatial-temporal patterns of three decoupling relationships, it was found that the improvement in HDI and GDP (per capita basis) slowed down during the 2015–2019 period, when the increase level in energy use and carbon emissions was still higher than the improvement in HDI and GDP. Spatially, although some provinces had strong decoupling between energy use and HDI, it was impossible for them to hold the status in the next cycles. The change in HDI and carbon emissions per capita was influenced by energy use structure, initial economic status, and population density. The decision tree analysis demonstrates that the similar feature for provinces achieving a decoupling in well-being, resource, and impact decoupling is final energy use per GDP reduced by >22% every five years. This finding does not only demonstrate one practical metric but also reveals the benefits of exploring three types of decoupling relationships together. These findings shed light on evaluating energy decoupling research at the subnational level to inform location-specific policies.