The decoupling effect and its driving factors of carbon emissions in China's three major urban agglomerations

Abstract

Achieving decoupling between economic growth and carbon emissions is a core requirement for China to attain its strategic “dual carbon” goals. As the primary spatial entities for economic activities and carbon emissions, urban agglomerations represent a critical battleground in this decoupling process; however, their decoupling pathways may exhibit significant variations due to differing development models. This study takes the three major urban agglomerations in China, namely the Beijing Tianjin Hebei (BTH), the Yangtze River Delta (YRD), and the Guangdong Hong Kong Macao Greater Bay Area (GBA), as research objects. It systematically examines the differentiated characteristics of their carbon decoupling status, green catch-up paths, and driving factors from 2013 to 2022. The findings reveal the following: (1) the decoupling process in the BTH exhibits significant volatility, reflecting a strong policy-driven nature. The decoupling status in the YRD remains generally stable, with weak decoupling maintained during most periods, highlighting its structural advantages as a pioneer in green development. The GBA demonstrates notable external sensitivity and structural resilience, with its path highly reliant on energy efficiency improvements and a service-oriented economic structure. (2) compared to benchmark cities, most cities in the BTH ultimately fall into negative catch-up, reflecting obstacles to green transformation under growth pressure and the vulnerability of surrounding areas. Most cities in the YRD shift from negative catch-up to expansionary catch-up, reflecting regional synergies without relying on high energy consumption for growth. The GBA gradually transitions from early negative catch-up in core cities to expansionary catch-up in most cities and even partial green catch-up in some, indicating a favorable development trend. (3) economic development is the dominant factor driving carbon emission growth, energy intensity serves as the core restraining force and plays a prominent role in the YRD and GBA, while the volatility of energy structure factors reveals that the replacement of clean energy still faces profound challenges