Underestimation of Methane Emissions From the Sudd Wetland: Unraveling the Impact of Wetland Extent Dynamics

Abstract Tropical wetlands account for ∼20% of the global total methane (CH 4 ) emissions, but uncertainties remain in emission estimation due to the inaccurate representation of wetland spatiotemporal variations. Based on the latest satellite observational inundation data, we constructed a model to map the long‐term time series of wetland extents over the Sudd floodplain, which has recently been identified as an important source of wetland CH 4 emissions. Our analysis reveals an annual, total wetland extent of 5.73 ± 2.05 × 10 4 km 2 for 2003–2022, with a notable accelerated expansion rate of 1.19 × 10 4 km 2 yr −1 during 2019–2022 driven by anomalous upstream precipitation patterns. We found that current wetland products generally report smaller wetland areas, resulting in a systematic underestimation of wetland CH 4 emissions from the Sudd wetland. Our study highlights the pivotal role of comprehensively characterizing the seasonal and interannual dynamics of wetland extent to accurately estimate CH 4 emissions from tropical floodplains.