Cold‐Season Methane Fluxes Simulated by GCP‐CH₄ Models

Cold-season methane (CH4) emissions may be poorly constrained in wetland models. We examined cold-season CH4 simulated by 16 models participating the Global Carbon Project model intercomparison and analyzed temporal spatial patterns simulation results using prescribed inundation data for 2000–2020. Estimated annual from northern (>60°N) wetlands averaged 10.0 ± 5.5 Tg yr−1. While summer were well compared to in-situ flux measurement observations, underestimated during September May relative total (27 9%, 45% observations) substantially months with subzero air temperatures (5 5%, 27% observations). Because of winter warming, nevertheless, contribution was increase at 0.4 0.8% decade−1. Different parameterizations processes, example, freezing–thawing snow insulation, caused conspicuous variability among models, implying necessity refinement.