More than 190 top international scientists are calling on the world to take urgent action on nitrogen pollution, to tackle the widespread harm it is causing to humans, wildlife and the planet.

The scientists highlight that “the present environmental crisis is much more than a carbon problem” and are asking all countries “to wake up to the challenge” of halving nitrogen waste from all sources globally by 2030.

Nitrogen, through its many forms – which include ammonia, nitrogen dioxide, nitrous oxide (‘laughing gas’, a greenhouse gas 300 times more powerful than carbon dioxide) and nitrate – is polluting our air, soil and water, posing a threat to human health, biodiversity, economies and livelihoods.

A future focus on sustainable nitrogen management would help prevent millions of premature deaths, help ensure food security, and simultaneously help protect wildlife and the ozone layer.

Currently, 80 per cent of nitrogen used by humans – including through crop, meat and dairy production, as well as via transport, energy, industrial and wastewater processes – is wasted and enters the environment as pollution. Nitrogen losses in UK are estimated at 1.4 million tonnes a year, at a market cost of US $1.4 billion, globally this amounts to 200 million tonnes a year at cost of US $200 billion.

UK scientists are leading global research efforts into the sustainable use of nitrogen in agriculture, transport and industry. Today [Oct 23] they have released a report outlining the problem and possible solutions, entitled ‘Nitrogen: Grasping the Challenge’, together with an open letter to António Guterres, Secretary General of the United Nations, asking him to mobilise global action.

The signatories of the letter are led by Professor Mark Sutton of the UK’s Centre for Ecology & Hydrology (CEH), who is Director of the UN Environment Programme (UNEP) International Nitrogen Management System (INMS) and co-chair of the UN-ECE Task Force on Reactive Nitrogen. The letter includes 197 signatories from 44 countries*.

They stress to Mr Guterres: “If we want to beat climate change, air pollution, water pollution, biodiversity loss, soil degradation and stratospheric ozone depletion, then a new focus on nitrogen will be vital.”

Nitrogen has many forms with multiple impacts in the environment:

  • Gases such as ammonia (NH3) and nitrogen dioxide (NO2) are key components of particulate matter, thereby contributing to poor air quality which can aggravate respiratory and heart conditions, leading to premature deaths
  • Nitrate from chemical fertilisers, manure and industry pollutes rivers, seas and soils posing a health risk for humans, fish, coral and plant life
  • Nitrous oxide (N2O) is a greenhouse gas that depletes the ozone layer and is 300 times more powerful than carbon dioxide.

The open letter comes as environment ministers attend the launch of a UN Global Campaign on Sustainable Nitrogen Management, being held in Colombo on October 23-24 under the lead of H.E. President Sirisena of Sri Lanka. The scientists have worked with Sri Lanka to develop a proposed Colombo Declaration to reduce nitrogen pollution, which highlights the ambition to ‘halve nitrogen waste’ and paves the way to establish a new international agreement to work together on nitrogen pollution. The Colombo event will also see the world premiere of a Nitrogen Song by Grammy® Award-winning songwriter Ricky Kej.

The report ‘Nitrogen: Grasping the Challenge’ has been produced by INMS which includes contributions from more than 70 UK and international science institutes, government agencies and companies. It highlights possible ways of reducing nitrogen pollution, including more efficient use and application of fertilisers and manure in agriculture; cutting food waste plus avoiding excessive meat and dairy consumption to reduce global production; and, new technology to recapture nitrogen oxide emissions from transport and fossil fuel burning. 

Professor Sutton says: “It’s vital we make the transition from a linear system of waste to a ‘circular economy’ for nitrogen to prevent large-scale losses that have an impact on human health, livelihoods and planet Earth.”

The UK’s Centre for Ecology & Hydrology leads both INMS and also the new GCRF South Asian Nitrogen Hub, which is receiving £17 million from UK Research and Innovation (UKRI) over the next five years. Looking at South Asia, the Hub’s research and resulting recommendations to support cleaner, more profitable farming and industrial recycling of nitrogen will provide a blueprint for global action.


Notes to editors

*Letter to Antonio Guterres

There are 197 signatories from 44 countries, including UK and across Europe, plus USA, India, China, Pakistan and Australia. They include Prof Helen ApSimon of Imperial College, Professor Penny Johanes of the University of Bristol, Prof Icarus Allen of Plymouth Marine Laboratory, Prof N. Raghuram (GGS Indraprathsa University, New Delhi) chair of the International Nitrogen Initiative (INI), Prof JN Galloway, founding chair of INI (University of Virginia) and Prof Eric Davidson, past President of the American Geophysical Union (University of Maryland).

The report Nitrogen: Grasping the Challenge
A summary is available for journalists (attached as a pdf at the bottom of this page). The full report will be published later this year.
There is information about the launch of the UN Global Campaign on Sustainable Nitrogen Management at https://papersmart.unon.org/resolution/node/286/

About Professor Mark Sutton
Professor Mark Sutton (@MarkNitrogen) is based at the Edinburgh Research Station of CEH. He is Director of INMS, a co-chair of the UN-ECE Task Force on Reactive Nitrogen and was chair of the INI from 2012 to 2018.  He leads the GCRF South Asian Nitrogen Hub and worked closely with India, Sri Lanka and other South Asian countries in drafting the Resolution on Sustainable Nitrogen Management, adopted this year at the 4th UN Environment Assembly (UNEP/EA.4/Res.14). His cooperation with the Government of Sri Lanka has enabled the launch of the UN Nitrogen Campaign, while stimulating the involvement of Grammy® Award Winner Ricky Kej to write the Nitrogen Song.

About the Centre for Ecology & Hydrology
The Centre for Ecology & Hydrology (CEH) is the UK’s centre for excellence in environmental science across air, land and water. CEH is a Natural Environment Research Council (NERC) research institute, part of UK Research and Innovation (UKRI). Our research extends from molecular biology to global climate modelling, and our fieldwork is carried out across the world, from the peatlands of Scotland to the semi-arid West African Sahel. For over 50 years, our experts have monitored and modelled environmental change, generating evidence-driven solutions to complex environmental challenges. We are home to around 500 environmental scientists, based across four sites in Edinburgh, Lancaster, Bangor and Wallingford. 
www.ceh.ac.uk    @CEHScienceNews

Contact information
For interviews and further information, please contact Simon Williams, Media Relations Officer at CEH, via simwil@ceh.ac.uk or 07920 295384.