ABOUT
Nitrogen is the most abundant element in the air we breathe. Without nitrogen there would be no life on Earth: no chlorophyll, no haemoglobin, no plants, or animals. While carbon gives the basic skeleton of organic matter, nitrogen is fundamental to life’s functioning and diversity.
The planet benefits because nitrogen allows a safe atmosphere in which life can flourish, while avoiding the flammable consequences of too much oxygen. Ultimately, without nitrogen there would be no life on Earth.
ECOLOGICAL STATUS AND TRENDS
However, excess of nitrogen waste in our environment also represents one of the most pressing pollution issues facing our planet today. Nitrogen is essential not in its pure form but in its reactive form combined with other elements such as oxygen, hydrogen, carbon etc. The natural processes of their formation called “nitrification” and their restoration by “denitrification” back to pure elemental nitrogen were fairly balanced till a century ago.
This balance was lost over time, when humans learnt how to harness the power of nitrogen; to pull it from the air and fix it into a plethora of reactive nitrogen forms (sometimes referred to as Nr), without the matching ability to denitrify their leftovers, leading to their accumulation and environmental pollution.
WHY DOES IT MATTER
There has been limited public discussion about the need to take action to #BeatNitrogenPollution to mitigate climate change. But it is an issue we cannot afford to ignore. If we do not limit nitrogen pollution now, we will face a cascade of negative impacts that jeopardise the environment, the economy, our well-being, and livelihoods -- from degraded ecosystems to polluted soil, water and air, and species loss.
WHAT WE DO
Since it is not nitrogen per se but excessive reactive nitrogen that is a threat, we must urgently improve our management of the nitrogen cycle to avoid inefficiencies and waste.
Political momentum for collective action on nitrogen is increasing. The United Nations Environment Programme (UNEP), the leading environmental authority in the United Nations system, is convening stakeholders to tackle nitrogen pollution globally.
In March 2019, the United Nations Environment Assembly - the world's foremost environmental decision-making body - adopted a resolution calling for sustainable nitrogen management. In March 2022, the Environment Assembly adopted a second resolution on the topic.
FACTS
- Nitrogen is the most abundant element in our atmosphere.
- Although 78 per cent of the atmosphere is nitrogen, this nitrogen exists almost entirely in a form that is unusable by most organisms.
- Atmospheric nitrogen can be made usable or ‘reactive’ through natural processes (e.g. nitrogen fixation by legumes such as soybeans) or artificially.
- The discovery a century ago of an industrial process that converted nitrogen in the air to ammonia, that made the manufacture of nitrogen fertilisers possible was followed by a spectacular increase in global food production.
- In the past 150 years, human-driven flows of reactive nitrogen have increased tenfold, contributing to a dangerous accumulation of unused reactive nitrogen.
- The uptake by crops of nitrogen as fertiliser is limited. Each year, 200 million tonnes of reactive nitrogen – 80 per cent – is lost to the environment, leaching into soil, rivers and lakes and emitted to the air. As a result, ecosystems are over-enriched, biodiversity is lost, and human health is affected. In some forms, it contributes to ozone depletion and climate change.
- The annual cost of lost nitrogen resources is estimated to be around US$200 billion.
AGREEMENTS AND CONVENTIONS RELATED TO UNEP’S MANDATE ON NITROGEN
- Nutrient management has been the subject of previous commitments for environmental action under the United Nations Environment Assembly (UNEA) (UNEA Resolution 3/10), with two specific initiatives taken to address sustainable nitrogen management (UNEA Resolutions 4/14 and 5/2).
- The Kunming-Montreal Global Biodiversity Framework (GBF) Target 7 addresses reducing excess nutrients lost to the environment as well as reducing the risk from pesticides. Phosphorus compounds are also used for several types of pesticide. Addressing target 7 is a prerequisite to achieving other targets, including those on ecosystem restoration (target 2) and protection (target 3).
