Spatiotemporal Change in Winter-Flooded Paddies Reduces CH 4 -Associated Climate Footprint in China’s Sichuan Basin

As the second most important anthropogenic greenhouse gas (GHG), methane (CH 4 ) has received wide attention in the mitigation of global climate change. China’s Sichuan Basin has been identified as one of the world’s hotspot regions with very high CH 4 emission intensity. Winter-flooded paddies are considered as potential significant sources of CH 4 emissions among various cropping systems in Sichuan. However, current studies are limited to the field scale, and there is a lack of research conducted over a large spatiotemporal scale. Here, we simulated CH 4 emissions from 1980 to 2023 at region scale using the Denitrification–Decomposition (DNDC) model and evaluated the associated climate impact using the radiative forcing-based climate footprint (RFCF) metric. We found that CH 4 emissions have recently decreased, from 0.53 billion tonnes in 2019 to 0.28 billion tonnes in 2023, representing a 47.20% reduction. Moreover, the climate footprint peaked in 2019 at 1.25 mW m −2 and decreased to 1.08 mW m −2 in 2023, and the system achieved net zero increase in radiative forcing (RF) in 2020. This means that Sichuan’s winter-flooded paddies no longer contribute to the additional RF in the atmospheric system. Overall, our findings demonstrate that the reduction in CH 4 emissions from winter-flooded paddies has been mainly attributed to a reduction in the cropping area and a decrease in average temperature during the rice growth season. These results provide a scientific basis for region-specific CH 4 mitigation policies and demonstrate how these spatiotemporal changes in CH 4 emissions from winter-flooded paddies in Sichuan can support sustainable agriculture.