Intra-urban air quality under future Representative Concentration Pathways: modeling experiments for an Eastern Mediterranean city

Urban air-quality responses to climate change remain poorly constrained at city scale. Here, we apply a 1 km TAPM framework over Athens (Greece), driven by ERA-Interim and CESM1.0/CMIP5 forcing under Representative Concentration Pathways RCP4.5 and RCP8.5. Simulations for 1995, 2046 and 2096 assess relative changes in nitrogen dioxide, ozone and particulate matter fractions (NO₂, O₃, PM_2.5 and PM₁₀). Mean NO₂ decreases exceed 40% across the city center and reach ~70% by the end of the century, while PM decreases by up to ~40% in the near future. O₃ responses are more spatially dynamic, reflecting precursor reductions, rising temperatures and regional conditions. The high-resolution framework also resolves enhanced basin ventilation under future conditions, associated with stronger northern flows and improved pollutant dispersion within the topographic heterogeneity of Attica. These findings demonstrate that kilometer-scale atmospheric numerical modelling can reveal pollutant-specific and intra-urban air-quality responses that are not captured by coarser-resolution approaches, and can provide spatial information relevant to climate adaptation planning in complex metropolitan regions.