Compliance with EU air quality limit values - A first set of sensitivity and optimization analyses

This report provides additional information to the baseline and optimized scenarios that have been developed for the review and revision of the Thematic Strategy on Air Pollution in TSAP Reports #6 and #7. The report examines the implications of different assumptions on the implementation of the Euro-6 emission standards for light duty diesel vehicles on compliance with NO2 air quality limit values in Europe. For the baseline assumptions of the TSAP-2012 baseline scenario, i.e., a decline of real-driving emission in two stages down to 1.5 times the value of test cycle value in 2018, it is estimated that almost all AIRBASE stations that have been modelled in this exercise would achieve the NO2 limit values by 2030 at the latest. However, in the least optimistic sensitivity case, i.e., under the assumption of a failure of Euro-6 (no change in real-driving emissions compared to Euro-4), about 100 out of the 1173 AIRBASE monitoring stations would still remain in non-compliance with the limit value in 2030. A second analysis examines the optimization results presented in TSAP Report #7 in more detail and provides, for each of the optimized scenarios, the sectors in which emission reductions would occur in the cost-optimal cases. These emission reductions will lead to lower background pollution concentrations in Europe, which will affect PM10 levels within cities. It is estimated, e.g., for the high ambition case, that in 2030 the number of stations for which non-compliance is robustly estimated will decline by about 20%. The number of stations for which compliance seems possible but not certain would fall by 30% compared to the baseline. In contrast, the optimized scenarios do not yield significant improvements in the compliance with NO2 limit values, as the series of scenarios did not consider further measures for road vehicle emissions. Finally, an initial assessment of current and future emissions of mercury in Europe suggests for the TSAP-2012 baseline a decline of Hg emissions of 22% in 2020 and about 30% in 2030 (relative to 2005), mainly as a consequence of lower coal use in the power sector. Full implementation of the available technical emission controls, especially of certain measures to reduce PM emissions, could eliminate Hg emissions in the EU by another third, so that in 2030 the total release of Hg in the EU could be more than 50% lower than in 2005.