Future scenarios for air quality in Europe, the Western Balkans and EECCA countries: An assessment for the Gothenburg protocol review

The Gothenburg Protocol (Protocol to Abate Acidification, Eutrophication and Ground-level Ozone) was first established in 1999 to support the enactment of the 1979 Convention on Long-range Transboundary Air Pollution. The Executive Body launched a review in December 2019 which was concluded in December 2022. In order to support the review and contribute to the assessment of the remaining risks for health, ecosystems and crops, model calculations have been performed on 2015, 2030 and 2050 emission scenarios which include both baseline and maximum technical feasible reduction (MFR) scenarios. The uEMEP/EMEP MSC-W modelling system has been applied for these calculations. uEMEP is a downscaling module for the EMEP MSC-W model that allows high resolution calculations, at 250 m for exposure, to be made. In this paper we document the input data, the model setup and present the calculated concentrations, exposure and source contributions based on emission scenario input from CIAM (Center for Integrated Assessment Modelling). The focus of this paper is on annual mean PM2.5 and NO2 at both existing monitoring sites and for population exposure in general. A comparison between three regions, namely the EU27+EFTA+UK, the Western Balkan, and EECCA countries is made. Comparison of current and future exposure to the WHO Guideline and Interim Target levels is also made. These 3 regions showed different exposure levels and different future trends. By 2030 the Baseline scenario indicates that 75% of the EU population will still be exposed to PM2.5 levels above 5μgm−3. However, this number is reduced to 40% in the 2050 Baseline calculation. The additional implementation of MFR in 2050 will reduce this further to just 14% of the population with exposure in excess of 5μgm−3. In this scenario, there is less than 1% of the population exposed to PM2.5 levels above 10μgm−3. For the Western Balkan and EECCA countries, the baseline scenario shows much less improvement in the PM2.5 levels. It is only with the implementation of MFR that significant improvement in these countries can be attained. The EECCA countries are limited in achieving lower concentration levels by high source contributions from wind blown dust. For NO2, all scenarios in 2050 showed that less than 2% of the EU population are still exposed above the WHO Guideline of 10μgm−3, while this share is 21% for the Western Balkan. For the 2050 baseline, the EECCA countries showed an increase in NO2 concentrations compared to 2015, with about 50% of the population being exposed to above 10μgm−3 and still with 13% of the population (33 million inhabitants) above 40μgm−3. It is only with the implementation of MFR that NO2 concentrations approach, but do not achieve, the WHO Guideline levels.