Decoupling carbon emissions from land use efficiency and its driving forces under carbon reduction goals

Under the global context of climate change mitigation, optimizing the decoupling relationship between land use efficiency (LUE) and carbon emissions (CE) has become a key pathway for carbon reduction. Addressing the insufficient understanding of spatiotemporal evolution characteristics and driving mechanisms of LUE-CE decoupling, this study aims to systematically explore the spatiotemporal patterns and influencing mechanisms of LUE-CE decoupling across 290 Chinese prefecture-level cities during 2000–2020. This study constructed a comprehensive analytical framework: the super-efficiency SBM model was employed to measure LUE, the decoupling model was utilized to identify decoupling types and spatiotemporal evolution characteristics, and the explainable machine learning model was innovatively introduced to quantitatively analyze key influencing factors and their temporal variations. Main findings were: (1) In general, LUE presented an increasing trend, while carbon emission intensity showed a declining trend. The decoupling relationship evolved from strong negative to weak decoupling. The proportion of cities achieving weak decoupling rose from 6.55% to 23.79%. (2) Eastern regional cities showed better decoupling performance, with weak decoupling accounting for 24.68% of the total number of cities in the region by 2020, while the northwest region only accounted for 9.09%, indicating a serious regional imbalance. (3) The driving factors of decoupling exhibited significant periodic evolution in four stages, with altitude, average temperature, energy consumption and altitude being the dominant factors in each of the four periods. The periodicity of altitude indicated that natural endowments played a fundamental role in various stages of development. These findings reveal pronounced spatial heterogeneity and temporal dynamics in China’s LUE-CE decoupling, necessitating differentiated regional strategies that integrate LUE-CE decoupling status into dynamic monitoring systems and coordinate land use efficiency improvements with carbon emission control.