A multifaceted assessment and response framework for land use-based carbon metabolism: From Intra-City to Inter-City dynamics

Carbon metabolism, a fundamental process in regulating the Earth's climate, is profoundly influenced by land use changes and is essential for developing strategies to mitigate global warming. This study formulates a three-pronged theoretical framework for assessing and responding to land use-based carbon metabolism. To address the limitations of existing research confined by jurisdictional boundaries, this framework designs a dual-node carbon metabolism network based on land uses and cities, thereby transitioning the research paradigm from intra-city analysis to regional integration. This approach reveals the intertwined impacts of land use changes and inter-city interactions on carbon metabolism while offering insights into how urban ecological relationships shape regional carbon environments. Moreover, it expands the temporal span of carbon metabolism assessment, incorporating both the retrospective evaluation for 1995–2020 and simulations of carbon evolution across different nodes in 2030. Concentrating on the Hangzhou metropolitan area in China, the study indicates that carbon metabolism exhibits uneven patterns across various dimensions. For carbon exchange between terrestrial and atmospheric systems, carbon emissions reached 49.79 × 10⁸ t in 2020, while carbon sequestration was only 218.88 × 10⁴ t. For terrestrial carbon exchanges, carbon flows are more responsive to inter-city interactions than to land use changes. The dominant Control/Exploitation ecological relationship elucidates that the environmental benefits of land use changes and inter-city linkages have yet to be maximized. From a long-term perspective, intervening in and balancing inter-jurisdictional land use patterns during the transition of decarbonization is necessary. Through developing this practical and replicable framework, this study identifies pivotal strategies for low-carbon development at the city-regional scale, aiding in a deeper and multi-dimensional understanding of urban carbon assessment.