German experts: Nitrogen cuts urgently needed

Nearly half of natural and semi-natural terrestrial ecosystems receive too much nitrogen. Photo: Andreas/ BY-NC-ND

Excessive emissions of nitrogen compounds into the environment pose a threat to human health, waterways, biodiversity, and the climate.

The release of too much nitrogen pollutants into the environment is one of the biggest problems of our time, according new report on nitrogen by the German Advisory Council on the Environment (SRU).

Nitrogen compounds, such as nitrogen oxides and ammonia, pollute the environment and endanger human health in numerous and complex ways:

  • Nitrogen-induced eutrophication and acidification contribute to biodiversity loss.
  • Nitrogen dioxide in ambient air damages human health directly, contributes to ground-level ozone formation, and together with ammonia forms hazardous particulate matter.
  • Nitrate in drinking water and food endangers human health; nitrosamines are suspected of being carcinogenic.

Nitrous oxide damages the ozone layer and contributes to climate change.

The SRU reports that nearly half of Germany’s natural and semi-natural terrestrial ecosystems are exposed to nitrogen deposition exceeding the critical limits for eutrophication, and 8 per cent are subject to excess acid deposition. Around 27 per cent of all German groundwater bodies exhibit a poor chemical status. And the annual limit value for nitrogen dioxide in ambient air is exceeded at more than two-thirds of locations in cities.

“Policy-makers need to address this major environmental problem with greater effort than in the past,” said Professor Karin Holm-Müller, deputy chair of the SRU, at the release in January of the new nitrogen report. If Germany is to meet current national and international environmental quality objectives, nitrogen emissions will have to be reduced by at least 50 per cent, according to the SRU.

The report contains more than 40 recommended measures. The top priorities are:

  • Amending the German Fertilizer Regulation, which would regulate the use of digestate and liquid manure, offers the chance to reduce nutrient spreading and at the same time roll back nitrate, ammonia and nitrous oxide emissions. Hence it could promote clean air, clean water, and climate protection. While the December 2014 draft bill would be a major step forward, it is not sufficient.
  • Supplementing existing regulations by imposing an environmental tax on surplus nitrogen in the agricultural sector.
  • Strengthening of EU clean air policies, in particular strict emission reduction targets for ammonia and nitrogen oxides for 2030 under the National Emissions Ceilings Directive.

In the interest of endowing this issue with more political clout and making the public more aware of the problem, the SRU recommends that a nitrogen strategy be jointly developed by the federal government and Germany’s regional-state governments.

Christer Ågren

The summary report “Nitrogen: strategies for resolving an urgent environmental problem” can be downloaded from The full report titled “Lösungsstrategien für ein drängendes Umweltproblem” is only available in German.

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