A new report commissioned by the United Nations Environment Programme (UNEP) highlights how humans have massively altered the natural flows of nitrogen, phosphorus and other nutrients. While this has had huge benefits for world food and energy production, it has caused a web of water and air pollution that is damaging human health, causing toxic algal blooms, killing fish, threatening sensitive ecosystems and contributing to climate change.

Our Nutrient World is launched at this week's UNEP Governing Council / Global Ministerial Environment Forum in Nairobi, Kenya, which runs until 22 February 2013. The study was carried out by almost 50 experts from 14 countries. Its lead author is Professor Mark Sutton of the Centre for Ecology & Hydrology (CEH).

The scientists suggest that a 20% improvement in nutrient use efficiency by 2020 would reduce the annual use of nitrogen fertilizer by 20 million tonnes. They term this global aspirational goal “20:20 for 2020”. Their analysis shows how this could provide a net saving worth around 110 (30 to 260) billion GB pounds per year. This figure includes implementation costs and financial benefits from reduced nitrogen use and improvements to the environment and human health.

Professor Sutton said, “Our analysis shows that by improving the management of the flow of nutrients we can help protect the environment, climate and human health, while addressing food and energy security concerns.”

The report stops short of recommending global legislation to control nutrient use, but recognizes that this a global problem, especially given the global trade in agricultural products. It calls for an intergovernmental framework to address these issues, and proposes a road map of how such an agreement would look.

Pollution sources considered in the report include emissions from agriculture and combustion of fossil fuel. Globally around 80% of harvested nitrogen and phosphorus is consumed by livestock rather than directly by people, showing how global nutrient supply and pollution are dominated by humans’ choice to consume animal products.

Key actions proposed

The report proposes a package of ten key actions to reduce these pollution threats, and makes recommendations for shared action by governments, business and citizens. Key points include:

  • Actions that improve the management of nutrients in agriculture, including crops, livestock and manure management. Measures include a range of techniques which are already available, but typically not yet applied, including precision agricultural methods suitable for both developed and developing countries. One example already being used in Bangladesh is to ‘plant’ large fertilizer pellets into the ground, preventing ammonia emission into the air.
  • Actions to reduce nutrient losses from industry and waste water treatment, including the recycling of available resources. A long-term ambition is identified to develop methods to recapture nitrogen oxides from combustion sources, which alone represents a lost resource worth around £25 billion per year.
  • Actions to improve local optimization of nutrient flows, connecting arable and livestock farming to improve nutrient recycling opportunities.
  • Lowering personal consumption of animal protein among populations consuming high rates by voluntary reduction and avoiding excess. With rapidly increasing meat and dairy consumption, as Asia and Latin America aspire to European and North American norms, our diet choices have a huge potential to influence future levels of global nutrient pollution.

"By improving the management of the flow of nutrients we can help protect the environment, climate and human health, while addressing food and energy security concerns."

Prof Mark Sutton, CEH

One of the co-authors, Dr Bruna Grizzetti, based at CNRS/Université Pierre et Marie Curie (UPMC) in Paris, said, “The option of localizing agricultural production is a really important one. Crop and livestock farming are often separated by many 100s of kilometres. Localisation helps improve nutrient recycling, reducing nutrient losses, while bringing the production benefits and pollution responsibilities closer together.”

The report also highlights how substantial progress has been made in some countries in reducing emissions from combustion sources and wastewater treatment. By comparison, much less progress has so far been made in reducing emissions from agriculture or regarding citizens' own choices. The relationships highlight the importance of working with key ‘cluster points’ in nutrient chains where a few key individuals or communities, such as local leaders, supermarkets and governments exercise substantial control.

Professor Sutton said, “One option is to extend and strengthen the mandate of an existing agreement called the ‘Global Programme of Action for the protection of the marine environment from land-based activities’ (GPA). By clubbing together to meet multiple global challenges for food, energy, water and air pollution, climate and health, a much stronger gravity to motivate action can be expected.”

CEH scientists Dr Clare Howard, Dr Stefan Reis and Professor David Fowler also contributed to the report.

Additional information

CEH issued a press release for this story.

Full reference: Sutton M.A. et al. (2013) Our Nutrient World: The challenge to produce more food and energy with less pollution. Global Overview of Nutrient Management. Centre for Ecology & Hydrology on behalf of the Global Partnership on Nutrient Management and the International Nitrogen Initiative. 114pp.

The report is available to download from International Nitrogen Initiative and Global Partnership on Nutrient Management websites.

Mark Sutton was interviewed about the report by BBC Radio 4 Today Programme (from 54 mins 30s - available until Monday February 25 2013) and BBC Radio 4 Farming Today (from beginning - available until Tuesday 26 2013).

Mark has written a blog about Our Nutrient World and his discussions at the United Nations Environment Programme General Assembly in Nairobi.

The Global Overview on Nutrient Management was commissioned by UNEP and conducted by the Global Partnership on Nutrient Management (GPNM) and the International Nitrogen Initiative (INI), under the lead of the UK’s Centre for Ecology & Hydrology. The commission was a direct response to the recognized success of the European Nitrogen Assessment, published in 2011, and seeks to go to the next stage to look at the global picture and the interactions between the nitrogen and phosphorus cycles. A four-minute video about the issues is available on YouTube.

UNEP 1st Universal Session of the Governing Council / Global Ministerial Forum, Nairobi, 18-22 Feb 2013

Related CEH links

CEH's Biogeochemistry Science Programme 

Excessive nitrogen harms the economy and environment – first Europe-wide assessment published - 11 April 2011



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