Revising EU ambient air quality standards—the implications for compliance in Europe towards 2050
This article presents the results of a modelling study carried out to examine how concentrations of key air pollutants (i.e. nitrogen dioxide (NO2), particulate matter (PM) and ozone (O3)) would vary under different emission reduction scenarios, and to assess how these might compare with the new WHO air quality guidelines and interim target metrics which are the basis for the proposed new ambient air quality standards under the revised EU Ambient Air Quality Directive.
The study uses a similar methodology to that supporting The Second Clean Air Outlook published by the European Commission in 2021 by considering three emission scenarios: a Current Legislation (CLE) trend scenario and two scenario assumptions about maximum emissions reduction potential (i.e. MTFR and MTFR + 1.5 LIFE). The study also considers some illustrative emission reduction scenarios that were simple cases where emissions from key sectors were set to zero in turn. The purpose was to determine whether emissions from any of the sectors had, individually, a dominating effect on future air quality.
The results of the study indicate that, overall, the outlook for 2030 and for 2050 is that air quality in Europe will improve. Larger improvements will result if consumption is reduced, as well as controls put in place and measures extended to agriculture. The majority of air quality monitoring stations will register short-term and long-term average concentrations that fall within the range of interim target values set out in the recently updated WHO air quality guidelines. However, even under the most ambitious MTFR + 1.5 LIFE scenario, air quality in Europe is unlikely to meet the WHO guideline values by 2050 at many locations in Europe covered by the current monitoring networks.