Decoupling Characteristics between Coupling Coordination Degree of Production-Living-Ecological Function and Carbon Emissions in the Urban Agglomeration of the Shandong Peninsula

Under the dual carbon goals, the relationship between land production-living-ecological function and carbon emissions points to a new direction for land spatial planning. This study compiles and analyzes carbon emissions and the production-living-ecological function coupling coordination degree of 16 cities in the Shandong Peninsula urban agglomeration for the years 2001, 2006, 2011, 2016, and 2021. Furthermore, it introduces the Tapio decoupling model to calculate the decoupling index between carbon emissions and the coupling coordination degree. The spatiotemporal evolution characteristics of production-living-ecological function coupling coordination, carbon emissions, and the decoupling index were analyzed. The results indicate that (1) from 2001 to 2021, the production-living-ecological function coupling coordination degree in Shandong Peninsula urban agglomeration increased overall, with an obvious &ldquo:high in the east and low in the west&rdquo: feature in the spatial pattern. That is caused by the difference in resource endowment between the east and the west and the gap in the process of urbanization, industrial structure transformation, and ecological governance. (2) During the study period, overall carbon emissions increased, with a significantly reduced growth rate. A polarization phenomenon of increase and decrease trends within the urban agglomeration was observed. The spatial distribution characteristics of land use carbon emissions showed significant production-living-ecological coupling coordination degree heterotropism. (3) From 2001 to 2021, the decoupling relationship between production-living-ecological coupling coordination degree and carbon emissions mainly exhibited three patterns: strong negative decoupling, expansion negative decoupling, and strong decoupling, maintaining a good decoupling trend overall. These results indicate that the coordinated development level of production, living, and ecological functions in the study area has improved during the research period, and its decoupling relationship with carbon emissions has also shown a positive trend. However, there is still a problem of uneven regional development. In the future, the production-living-ecological development of Shandong Peninsula urban agglomeration should adhere to the development pattern of &ldquo:two circles and four regions&rdquo:, which aims to promote resource sharing and complementary advantages through specific regional divisions, and achieve coordinated development within the region. This involves optimizing land use structure and function, encouraging innovation and development of green industries, and deepening ecological environment restoration and protection to realize the coordinated development of the production-living-ecological function of land use under the dual carbon goal.