Rising summer temperatures caused by the urban heat island (UHI) has considerable effects on the physical and mental health of urban residents globally. To categorize residents’ health risk areas and evaluate the characteristics of...

Carbon emissions are a critical global issue requiring detailed spatial analyses to support regional carbon peak and neutrality strategies. This study investigates the spatiotemporal evolution and spatial differentiation of county-level land-use carbon emissions (CELU) in the Changchun-Jilin-Tumen (CJT) region from 2012 to 2021 by integrating land use data, nighttime light imagery, and socio-economic statistics with the Optimal Parameter Geodetector (OPGD) model. The analysis identifies key drivers of spatial emission variability, including construction land proportion (q-value: 0.8882), land area per capita (q-value: 0.7609), and urbanization rate (q-value: 0.5875), underscoring the significant role of land-use patterns and urbanization. Results show a 21.2% increase in CELU, from 67,594.46×104 t in 2012 to 81,942.35×104 t in 2021, with emissions concentrated in industrially active and urbanized western and southern counties, while forest-rich central and eastern counties exhibit lower emissions. Using the Grey Model (GM (1,1)), the study forecasts that CELU will rise from 78,484.364×104 t in 2022 to 88,985.198×104 t by 2030, reflecting a 14% increase over the forecast period. This trajectory highlights the misalignment between current trends and the region's goals of creating a "low-carbon industrial zone" and "livable cities," emphasizing the need for transitioning to renewable energy, optimizing industrial structures, and implementing sustainable land-use practices such as brownfield redevelopment and ecological land protection. By combining advanced remote sensing with nonlinear spatial analysis, this study offers a replicable high-resolution framework for understanding carbon emission drivers and spatial patterns, providing actionable insights for refining carbon reduction strategies and achieving sustainable development goals at both national and global scales.