A National Nitrogen Target for Germany

Abstract

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 and cause numerous negative impacts on the environment. The complex nature of the nitrogen cycle hampers public awareness of the nitrogen problem. To overcome this issue and to enhance the sensitivity for policy action, we developed a new, impact-based integrated national target for nitrogen (INTN) for Germany. It is based on six impact indicators, for which we derived the maximum amount of nitrogen losses allowed in each environmental sector to reach related state indicators on a spatial average for Germany. The resulting target sets a limit of nitrogen emissions in Germany of 1053 Gg N yr−1. It could serve as a similar means on the national level as the planetary boundary for reactive nitrogen or the 1.5 °C target of the climate community on the global level. Taking related uncertainties into account, the resulting integrated nitrogen target of 1053 Gg N yr−1 suggests a comprehensible INTN of 1000 Gg N yr−1 for Germany. Compared to the current situation, the overall annual loss of reactive nitrogen in Germany would have to be reduced by approximately one-third.

Assessing nitrate groundwater hotspots in Europe reveals a severely inadequate designation of Nitrate Vulnerable Zones

“…Only some NO3hotspots are reflected by high N surplus (Batool et al, 2022), such as in Spain, Italy and Germany; this is likely related to the time-lag effect of NO3pollution (see below). Our results are similar to those from studies in Germany (Geupel et al, 2021;Ortmeyer et al, 2023) and Portugal (Serra et al, 2023b), even though our predictions were lower and higher for NW Portugal and NE Germany, respectively.…”