Leading scientists and politicians will outline how action on nitrogen is necessary to meet global climate goals, at the start of the COP26 summit in Glasgow.

Professor Mark Sutton of the UK Centre for Ecology & Hydrology is leading a side-event of the crucial climate conference on 31 October 2021, which will be also streamed via the internet. Speakers will include the President of Sri Lanka, Gotabaya Rajapaksa; Julie Fitzpatrick, Chief Scientific Adviser for Scotland; Inger Andersen, Under Secretary General of the United Nations and Executive Director of the UN Environment Programme; Baroness Scotland, the Commonwealth Secretary-General; and Dr Masumur Rahman, Director General of the South Asia Co-operative Environment Programme.

At COP26, which runs for two weeks, world leaders will discuss progress on global attempts to reduce greenhouse gas emissions and meet the targets set out in the Paris Agreement – to keep global warming well below 2 degrees Celsius above pre-industrial levels and ideally 1.5 degrees Celsius – in order to avoid catastrophic effects on people and wildlife.

However, Professor Sutton says international discussions about reducing greenhouse gases to tackle climate change largely focus on carbon emissions, but rarely on nitrogen. Nitrous oxide (N20) is estimated to be responsible for six per cent of global greenhouse gas emissions, with a warming potential 300 times that of carbon dioxide (CO2) and is also now the main substance that depletes the ozone layer. Other forms of nitrogen pollute air and water and represent a waste of valuable nitrogen resources.

Professor Sutton, who will discuss nitrogen with Guardian journalist Patrick Greenfield as part of the side-event broadcast, says: “With the upcoming 250-year anniversary of the scientific discovery of this vital chemical element in Scotland, the COP26 summit in Glasgow is a key moment to 'rediscover’ nitrogen to inform climate and environmental action.

“It is impossible to achieve net zero greenhouse gas emissions without managing nitrous oxide emissions. This will require system-wide changes to the way that humans manage the global nitrogen cycle, which will have multiple benefits – for climate, the environment, food security, health and the economy."

Gases such as ammonia (NH3) and nitrogen dioxide (NO2) are key components of particulate matter, thereby contributing to poor air quality that 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.

Nitrogen pollution caused largely through inefficient use of fertilisers, manure and wastewater, as well as unintended emissions from combustion sources – also has significant financial consequences. Global losses total an estimated 200 million tonnes a year, at a cost of US $200 billion. An international initiative launched earlier this year by UKCEH with governments and scientists in South Asia – called #Nitrogen4NetZero – calls on countries to take efforts to better manage nitrogen waste, including halving losses from all sources globally by 2030.

In-person attendance at the COP26 side-event, ‘Rediscovering Nitrogen: Solutions and Synergies for Climate Change Health, Biodiversity and Circular Economy’ is by invitation-only, but you can watch it being streamed on the internet here from 7pm-8pm GMT on 31 October 2021.

There is more information about the #Nitrogen4NetZero initiative on the International Nitrogen Management System (INMS) website.