News Release

Call for united global effort to tackle nitrogen pollution

World Environment Day summit in India calls for joined-up approach

Business Announcement

UK Centre for Ecology & Hydrology

Governments, industries and farmers across the world must join together to tackle the 'major unsolved challenge' of nitrogen pollution, experts told a World Environment Day summit in India today (June 4).

Nitrogen poses multiple threats to human health and the environment, as it is simultaneously contributing to poor air and water quality plus climate change.

Some 80% of the nitrogen from fertilizers and manure is lost to the atmosphere and water courses, which is compounded by emissions from vehicles and factories. Added up, these flows cause a cocktail of worsening nitrogen pollution.

Nitrogen is the largest fraction of PM2.5 (particulate matter) air pollution that gets deep in to lungs and contributes to cardiovascular and respiratory illness, while in drinking water it increases the risk of cancer.

Nitrogen pollution through the air, water and soil is also a major cause of loss of biodiversity. For example, it stimulates growth of certain plantlife such as rough grasses at the expense of more sensitive species with a high conservation value and also increases algal blooms, which cause the death of fish by reducing oxygen levels in water.

Despite all this, there has been little global action to tackle the problem, according to Prof Mark Sutton of the UK's Centre for Ecology & Hydrology, who heads a UN-backed global coalition of scientists and institutions ¬ which aims to fight pollution by promoting better management of the nitrogen cycle.

The environmental physicist, who is director of INMS (International Nitrogen Management System), led an international seminar in New Delhi a day before annual World Environment Day (June 5), which this year is hosted by India.

The panel of speakers at the session also included Prof N. Raghuram, president of the Indian Nitrogen Group, and WWF International president Pavan Sukhdev, at an event including Indian government ministers, scientists and other stakeholders.

Opening the session, titled Nitrogen: Joining up for a Cleaner Environment, today (June 4) in New Delhi, Prof Sutton explained there were many benefits of good nitrogen management. He said: "By joining up across the nitrogen cycle we aim to combine the environmental and economic arguments that will help mobilise governments, farmers and industry to manage the world's nitrogen more effectively."

While the problem and effects of pollution from vehicle emissions on air quality, human health and climate change is widely known, the impact of nitrogen pollution from agriculture has been less well publicised.

As part of his efforts to make India more environmentally friendly, prime minister Narendra Modi has asked the country's farmers to cut consumption of nitrogen-based fertilizers by half by 2022. Prof Sutton suggested that in addition to reduced use of such fertilizers by farmers across the world, there should also be more effective recycling of existing nitrogen sources such as excrement.

Prof Raghuram, who co-led the first Indian Nitrogen Assessment (2017), added: "As fertilizer, nitrogen is one of the main inputs to agriculture, but inefficiencies along the food chain mean about 80% of nitrogen is wasted, contributing to air and water pollution plus greenhouse gas emissions, thereby causing threats for human health, ecosystems and livelihoods.

"Timely scaling up of the recent initiatives of the Indian government towards improving nitrogen fertilizer use efficiency, rural toilets, sustainable fuels etc can moderate India's nitrogen footprint on a scale that few countries can match."

Meanwhile, in industry, a huge nitrogen resource is lost when nitrogen oxides from combustion are emitted to the atmosphere, exacerbating air pollution. Prof Sutton advocates improving methods to recapture nitrogen oxides and turn them into nitrates, which could be used by the chemical industry for uses such as fertilizer.

Prof Sutton said: "Everyone knows about climate change and carbon footprints, but how many people are aware that nitrogen pollution is just as significant? Different experts have focused on different parts of the nitrogen story and few have investigated how all the issues fit together.

"Addressing the nitrogen challenge therefore requires us to pool our technical expertise and, due to the trans-boundary nature of nitrogen pollution, international co-operation is also essential if we are to make substantial progress.

"We must build on joint endeavours, such as INMS, while learning from the international experience of others."


1) The panel for the session Nitrogen: Joining up for a Cleaner Environment, held as part of a World Environment Day dialogue series at the Vigyan Bhavan, New Delhi, on June 4 comprised:

  • Prof Mark Sutton of the Centre for Ecology & Hydrology, UK

  • Prof Nandula Raghuram, president of the Indian Nitrogen Group, which is made up of the country's nitrogen researchers. He is dean of Biotechnology at the GGS Indraprastha University.

  • WWF International president Pavan Sukhdev

  • Urmi Goswami, journalist at The Economic Times, an English language daily newspaper based in New Delhi.

  • Vijay Kumar, senior adviser and head of the Zero Budget Natural Farming Programme for the Indian state of Andhra Pradesh.

  • Dr Mohammad Khurshid, director general of the South Asia Co-operative Environment Programme (SACEP), an inter-government organisation that promotes and supports protection, management and enhancement of the environment in the region.

2) The session discussed how tackling nitrogen could help India progress towards achieving the UN's Sustainable Development Goals by highlighting where interventions are possible, potential environmental and social benefits, and outlining the intergovernmental processes for nitrogen management.

3) 50% of India's workforce is employed in agriculture and £7bn is spent subsidising the fertilizer industry, cutting the product cost to farmers by 70%. India is the second largest consumer of urea (the major form of nitrogen fertilizer) at 30m tonnes a year. Prime minister Narendra Modi has set the country's farmers a target to halve urea consumption by 2022.

4) INMS (International Nitrogen Management System) was launched in December 2016 as a US $60m initiative, spearheaded by UN Environment, to support the development of international policy to improve global nitrogen management. See

5) Underpinning primary science to improved nitrogen use efficiency in India is being undertaken through the NEWS India-UK Virtual Joint Centre, funded in the UK by BBSRC and India by the Department of Biotechnology, co-lead by Profs Sutton and Raghuram. See

6) Members of the South Asia Co-operative Environment Programme, with the support of INMS, have developed a draft Nitrogen Resolution for submission to the fourth session of the UN Environment Assembly (UNEA-4) in Nairobi in March 2019. It calls on UN Environment to develop a more coherent framework for better management of the global nitrogen cycle.

7) INMS is led by its director, Prof Mark Sutton, an internationally renowned expert on nitrogen, who is also chairman of the International Nitrogen Initiative. An environmental physicist, he has worked for the Centre for Ecology & Hydrology (CEH), based in Edinburgh, for 25 years.

To arrange a media interview with Prof Mark Sutton, please contact Simon Williams, media relations officer at CEH, on 07920 295384 or email


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