In an open letter to UN secretary general António Guterres, the scientists, hailing from institutions such as the UK Centre for Ecology and Hydrology, the Potsdam Institute for Climate Impact Research and the German Environment Agency, say nitrogen waste from all sources globally must be halved by 2030.
Nitrogen, through its forms – which include ammonia, nitrogen dioxide, nitrous oxide and nitrate – is polluting “air, soil and water, posing a threat to human health, biodiversity, economies and livelihoods”, the letter states.
Currently, 80% 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, says the letter, with nitrogen losses in the UK 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, according to the scientists.
Better management would “prevent millions of premature deaths, help ensure food security, and simultaneously help protect wildlife and the ozone layer”, they say.
The letter is accompanied by a report, ‘Nitrogen: Grasping the Challenge’, 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 Mark Sutton of the Centre for Ecology & Hydrology said: “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.”