Regionally Differentiated Methane Mitigation Pathways toward the 1.5 °C Target using Large-Scale Socio-Ecological Observations

Observation-based constraints on methane mitigation pathways are essential to meet the global 1.5 °C target, especially in large fossil-fuel-dependent economies undergoing rapid structural transition. China is a particularly informative case given its scale, sectoral heterogeneity, and recent emission inflection. While fossil-fuel-related methane emissions in China have declined in recent years, a systematic long-term analysis of national emission trajectories, spatial heterogeneity, and targeted mitigation strategies remains lacking. Here, we develop a transferable Emission–Economy–Ecology–Well-being (E3W) coupled system framework to characterize heterogeneous methane emission trajectories across fossil-fuel and urban systems. China serves as a large-scale testbed to demonstrate the framework under complex, multi-sectoral conditions. Integrating top-down and bottom-up approaches, the framework combines 38 years of methane inventories (1986–2023), satellite-derived ecological indicators, and socio-economic datasets, providing a systematic basis for regionally tailored and phased mitigation strategies. Results show that total methane emissions exhibit a downward inflection after 2022, whereas extreme events declined around 2010, revealing asynchronous turning points between mean and extreme emissions. Urban emissions follow a logistic (S-shaped) trajectory, while mining emissions display a skewed near-normal distribution with rapid peaks and prolonged gradual declines. Nighttime light intensity accounts for ~45.7% of urban methane fluxes, while ecological factors, temperature, and precipitation exert spatially heterogeneous regulation. Some gas-rich mining areas reduce emissions below pre-extraction levels within 3–5 years. These findings highlight that regionally tailored mitigation strategies, prioritizing urban systems and accelerating ecological restoration in mining areas, are essential to avoid climate tipping points and support the 1.5 °C target. These findings offer transferable insights for designing real-zero methane pathways in other fossil-fuel-dependent economies, supporting both climate mitigation and sustainable land-use planning.