Towards improved bottom-up inventories of methane from the European land surface

► Ways of improving bottom-up inventories of methane source or sink ecosystems shown. ► Plausible range for the net European ecosystem methane balance given. ► Wet forest soils likely to be as important as wetlands as methane sources. ► Methane release from wetlands of continental Europe potentially crucial - data utterly needed. ► Precise determination of the area of methane sources is the key to improvements.