Spatiotemporal dynamics and driving mechanisms of agricultural plastic film carbon emissions in China: from the LightGBM-SHAP

Agriculture is a major source of carbon emissions, and the widespread use of plastic film in China has raised growing environmental concerns. To address this issue, this study develops the SDETI framework (Spatiotemporal characteristics-Dynamic evolution-Explanation-Threshold-Interaction) to investigate the spatiotemporal evolution and driving mechanisms of agricultural plastic film carbon emissions. Based on the panel data from China's 31 provinces from 1997 to 2022, this study evaluates the agricultural plastic film carbon emissions and analyses across multiple dimensions. The study indicates that China's agricultural plastic film carbon emissions fluctuated between 1997 and 2022, peaking in 2015 at 13.49 million tCO 2 e (with a provincial average of 0.44 million tCO 2 e), and then gradually declining in recent years, with total emissions stabilizing below 12.30 million tCO 2 e and the average around 0.40 million tCO 2 e after 2020. Specially, emissions were generally higher in the western and northern regions and lower in the eastern and southern regions. Furthermore, China's agricultural plastic film carbon emissions followed a multi-peak distribution with an initial rise and subsequent decline, showed a strong club convergence effect, and displayed a diffusion pattern shifting from the southeast to the northwest with increasing spatial dispersion. Meanwhile, agricultural machinery power (MACH) and plastic film usage (PFU) are identified as dominant factors, exerting heterogeneous and increasing agricultural plastic film carbon emissions in many regions. Furthermore, high input intensity, mechanization, and large-scale operations are found to amplify emissions, reflecting both regional disparities and synergistic input-driven effects. The integration of dynamic analytical methods with the LightGBM-SHAP framework enhances understanding of the spatiotemporal heterogeneity of agricultural plastic film emissions in China and provides evidence to support ecosystem management and the transition toward low-carbon agriculture.