A national nitrogen target for Germany
The anthropogenic nitrogen cycle is characterized by a high complexity. Different reactive nitrogen species (NH3, NH4, NO, NO2, NO3 and N2O) are set free by a large variety of anthropogenic activities. At the same time the release of reactive nitrogen has negative impacts on the environment, such as loss of aquatic and terrestrial biodiversity, deterioration of groundwater and surface water quality, air pollution and the emission of greenhouse gases. To enhance public awareness and the sensitivity for policy action, we developed a new, impact-based integrated national target for nitrogen (INTN) and present its first calculation for Germany.
A national nitrogen target is a very good approach to combine the media-related quality targets for nitrogen. The ambient NH3-concentration seems to be the most important species (impact indicator No. 1; here compliance with 3 µg / m3 NH3 to protect the higher plants). In the long term, protecting lower plants according to the EU Directive 92/43/EEC should also be included in the national nitrogen target (locally compliance with 1 µg /m3 NH3).
Thanks for this relevant comment. In our project we tested the influence of including the most sensitive Critical Level on our integrated target value. Details will be published in our final report, soon to be published on https://www.umweltbundesamt.de/en/publications. Applying the Critical Level of 1 µg m-3, the INTN would result to be around 700 kt N a-1, instead of the proposed 1.000 kt N a-1.
1.000 kt N a-1 is an iterim target, which in a first step is in line with current legislation until 2030 (e.g. NH3 from NEC-Directive) and which will not guarantee compliance with the long-term goals for the protection of human health and the environment.