Environmental Footprint of Diffuse Emissions in European Functional Urban Areas

ABSTRACT This paper quantifies the environmental footprint of diffuse air emissions across 776 European functional urban areas (FUAs) from 2005 to 2022 by coupling Copernicus Atmosphere Monitoring Service (CAMS) gridded inventories with the Environmental Footprint (EF) 3.1 framework. CAMS emissions are harmonised into 12 GNFR sectors and nine pollutants, spatially allocated by GIS overlays to FUAs and surrounding territories using a largest‐overlap rule to obtain an explicit In/Out FUA split, and translated into EF 3.1 impacts through characterisation. Impacts are aggregated into a policy‐ready Weighted and Normalised Footprint Indicator (WENFIp) using EF 3.1 normalisation and weighting, with intensity (WENFId) and per‐capita (WENFIcap) derivatives. Results show an overall ~25% decline with a 2020 trough, a broadly stable In/Out FUA balance, urban burdens dominated by fossil CO 2 and PM 2.5 , and non‐urban burdens dominated by NH 3 and CH 4 . Clustering of EF profiles identifies four robust FUA archetypes, supporting differentiated, just mitigation portfolios.