Critical load exceedances under equitable nitrogen emission reductions in the EU28

Abstract

The ecosystem area in the 28 states of the European Union (EU28) for which eutrophication critical loads are exceeded is investigated under the revised National Emission Ceiling Directive (NECD) and under alternative scenarios whereby reduction efforts are shared equitably among Member States. The focus is on nitrogen oxide (NOx) and ammonia (NH3) emission reduction policies that ensure that the total EU28 emission reduction target for 2030 under the NECD is achieved, but by equity-based emission reductions for each Member State. A gradual reduction of emissions of nitrogen in the EU28 is assessed by imposing ever lower common maximum densities for emissions (a) per unit area of a country (areal-equity) (b) per capita of a country's population (per capita-equity), and (c) per euro (€) of a country's GDP (GDP-equity). The NECD aims at a reduction of EU28 emissions of NOx and NH3 of 63% and 19%, respectively in 2030, compared to base year 2005. Under these reductions, about 67% of EU28 ecosystem area remains at risk of adverse effects of nitrogen deposition. We demonstrate that reducing N emissions subject to GDP-equity among EU28 Member States could have reduced that area at risk to about 61%. The application of areal and per capita-equity does not lead to significantly different ecosystem areas at risk when compared to NECD.