The impact of nitrogen and sulphur emissions from shipping on exceedances of critical loads in the Baltic Sea region

Abstract. The emissions of nitrogen (N) and sulphur (S) species to the atmosphere from shipping significantly contribute to S and N deposition near the coast, and to acidification and/or eutrophication of soils and freshwaters. In the countries around the Baltic Sea the shipping volume and its relative importance as a source of emissions are expected to increase if an efficient regulation would not be implemented. To assess the extent of environmental damage due to ship emissions for the Baltic Sea area, the exceedance of critical loads (CLs) for N and S has been calculated for the years 2012 and 2040. The paper evaluates the effects of several future scenarios including the implementation of NECA and SECA (Nitrogen resp. Sulphur Emission Control Areas). The implementation of NECA and SECA caused a significant decrease in exceedance of critical loads for N as a nutrient while the impact on the – already much lower – exceedance of critical loads for acidification was less pronounced. The relative contribution from Baltic shipping to the total deposition decreased from 2012 to the 2040 scenarios for both S and N. In contrast to exceedances of CLs for acidification, shipping still has an impact on exceedances for eutrophication in 2040.