Global methane emissions from rice paddies: CH4MOD model development and application

    Rice cultivation constitutes a significant anthropogenic methane (CH₄) source and a crucial target for CH₄ mitigation. However, global and regional emissions remain poorly constrained. In this study, we validated a global process-based CH₄ model for rice paddies (CH4MOD), analyzed the sensitivity of major emission drivers, and simulated management scenarios involving four water regimes and three organic matter amendments. The model was applied to simulate historical CH₄ emissions from global rice paddies from 1961 to 2020. In this study, we demonstrate the capabilities of CH4MOD in simulating rice paddy CH₄ emissions globally, under various environmental conditions and management practices, elucidating the primary drivers of CH₄ emissions. We also present high-resolution, long-term CH₄ emissions modeled with three main approaches: process-based modelling (i.e., CH4MOD), IPCC Tier 1 method, and machine learning techniques. This research contributes to enhance the understanding of CH₄ emissions from the rice paddies in the context of climate change, while providing a scientific basis for future policies and practices aimed at mitigating CH₄ emissions from agriculture.