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Reactive Nitrogen

Atmospheric di-nitrogen (N2) makes up 80 per cent of our atmosphere. However, over the past 100 years, humans have converted N2 into many reactive nitrogen (Nr) forms, through fertilizer and munitions manufacturing and burning of fossil fuels. This has caused unprecedented changes to the global nitrogen cycle, leading to a doubling of the flow of nitrogen compounds around the world in the past 100 years. Nitrogen (N) is important for plant growth and sufficient amounts are needed for plants to achieve optimum crop yields. However, about 80 per cent of nitrogen is lost from agriculture through leaching and run-off of nitrate or organic nitrogen and gaseous emissions to air.

The nitrogen that is lost to the environment has severe impacts on soils, air and freshwaters. This, in turn, affects ecosystems and biodiversity, climate and human health. While the world’s carbon cycle has received a lot of attention through climate change, public awareness about the world’s nitrogen cycle and the impacts of its imbalance is low. It has been suggested that the world’s planetary boundaries for interference with the nitrogen cycle have already been surpassed.

In many parts of the UNECE region, over-fertilization and deposition of too much atmospheric nitrogen acidify natural and agricultural soils, leading to a loss of arable land. Excess nitrogen loads also affect water quality and can lead to aquifers contaminated with nitrate and impure drinking water. Finally, interactions with nitrogen and its transformations also have an impact on the greenhouse gas balance with consequences for climate change.

The Task Force on Reactive Nitrogen has the long-term goal of developing technical and scientific information, and options which can be used for strategy development across the UNECE to encourage coordination of air pollution policies on nitrogen, and may also be used by other bodies outside the Convention in consideration of other control measures. The Task Force also continues the work of the former Expert Group on Ammonia Abatement, including regular updating of the Guidance document on preventing and abating ammonia emissions and the Framework Code for Good Agricultural Practice for Reducing Ammonia Emissions, as well as contributing to the improvements of the methodologies on the emission inventories and other activities, as required.

It was established under the Working Group on Strategies and Review (WGSR) by Executive Body decision 2007/1.

The Task Force is led by Denmark in line with decision 2014/3. For more information, please consult the Task Force's dedicated website.

Reports of the Task Force meetings:


Report to the 53rd session of the Working Group on Strategies and Review


Report to the 52nd session of the Working Group on Strategies and Review


Report to the 51st session of the Working Group on Strategies and Review


Report to the 50th session of the Working Group on Strategies and Review


Report to the 49th session of the Working Group on Strategies and Review