High-resolution methane emissions inferred from TROPOMI and GOSAT satellite inversions over western and central Europe

Top-down inversion of satellite observations is a powerful tool used to identify sources of atmospheric methane and to evaluate bottom-up emission estimates, providing essential information for achieving short-term climate mitigation goals. Recent satellite inversions indicate an increasing trend in methane emissions and an underestimate in the bottom-up estimates reported to the United Nations Framework Convention on Climate Change (UNFCCC) over Europe, but these results have been limited by coarse resolution and temporal coverage. Here we use satellite observations from TROPOMI and GOSAT to estimate methane emissions at 25 km resolution over western and central Europe during 2019 and 2024, respectively, using the Copernicus Atmospheric Monitoring Service (CAMS) and Global Fuel Exploitation Inventory (GFEI) anthropogenic emissions as prior estimates. Our high-resolution top-down posterior estimates suggest an upward correction in CAMS livestock (17−29%) and waste (5−29%) emissions, and a downward correction in GFEI coal (63−65%) emissions. The total posterior estimates for 2019 and 2024 are 17.7 Tg and 19.7 Tg, respectively, indicating a 2024 versus 2019 increase, attributed to livestock and waste, especially in Italy and Spain, which is not shown in the CAMS bottom-up emissions.