Facts about Nitrogen Pollution

UNEP
UNEP

Why does nitrogen pollution matter?

Nitrogen pollution is causing an environmental catastrophe with devastating consequences for planet Earth, yet the scale of the problem remains largely unknown outside of scientific circles.

Nitrogen – the good and the bad

  • 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 fertilizers 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 fertilizer 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 lost and human health 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..
In Chemicals & pollution action

How does nitrogen pollution harm the environment and human health?

Climate change and the ozone layer

  • Nitrous oxide is 300 times more potent than methane and carbon dioxide as a greenhouse gas.
  • It is also the biggest human-made threat to the ozone layer.
  • With an atmospheric lifetime of 200 years, nitrous oxide poses a much more long-term threat than other forms of pollutants.

Biodiversity and ecosystems

  • Nitrogen pollution is the biggest driver of biodiversity loss on the planet, after habitat destruction and greenhouse gas emissions.
  • Nitrogen pollution can degrade soils.
  • It can cause the inadvertent fertilization of trees and grasslands or nitrogen tolerant species to outcompete more sensitive wild plants and fungi.
  • Nitrogen pollution can create “dead zones” in the ocean and cause toxic algal blooms to spread in marine ecosystems.

Air

  • Nitrogen oxides generated from coal power plants, factory emissions and vehicle exhausts, can lead to smog and ground-level ozone.
  • An estimated 77 per cent of people breathe annual average concentrations of nitrogen dioxide beyond safe levels.
  • Agricultural ammonia emissions combined with pollution from vehicle exhausts create extremely dangerous particulates in the air, which can exacerbate respiratory diseases.
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Why do we urgently need to reduce nitrogen pollution?

Sustainable nitrogen management is needed to live in harmony with nature on a planet that is pollution-free and climate-stable.

It is essential to achieving the Sustainable Development Goals and securing a cleaner, healthier environment for future generations.

It would prevent millions of premature deaths and debilitating ill-health, while helping to protect wildlife and the ozone layer.

It would also boost food production, since cutting emissions of nitric oxide and nitrogen dioxide by half could increase crop yields in China by 25 per cent, 10 per cent in Europe and up to 8 per cent in India.

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What can we do to fix nitrogen pollution?

There is no single solution to reducing nitrogen pollution. But everyone can play a part in stopping it from poisoning our lakes, rivers, air and soil.

Governments can:

  • Accelerate joint progress on nitrogen-related challenges through Multilateral Environmental Agreements.
  • Deliver on the Colombo Declaration to halve nitrogen waste by 2030 by investing in research to reduce nitrogen loss from synthetic fertilizers.
  • Support the shift towards organic fertilizers.
  • Improve reporting and data collection capacity to identify nitrogen sources.

The private sector can:

  • Phase out the use of synthetic, chemical fertilizers.
  • Improve management of livestock waste to use it as organic fertilizers.
  • Adapt protein in livestock diets to reduce nitrogen losses through waste.

The public can:

  • Advocate for the proper management and phasing out of nitrogen in fertilizers and other products.
  • Urge governments to sign the Colombo Declaration and join Multilateral Environmental Agreements tackling nitrogen.
  • Alter dietary choices to reduce consumption of meat, dairy and eggs.
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USD $100

Billion

could be saved by setting an ambitious goal to reduce nitrogen waste.

Today, nitrogen pollution is one of the most pressing pollution issues facing humanity, threatening our environment, health, climate and ecosystems.

Countries must step up their joint efforts to reduce nitrogen waste by 2030. From addressing the sources of nitrogen pollution to adopting a strategy to manage nitrogen at every step of its cycle, we must work together to #BeatNitrogenPollution: