Rising Nitrous Oxide Emissions Threaten 1.5°C Goal, May Cause 20 Million Deaths by 2050, UN Report Finds

The new United Nations Global Nitrous Oxide Assessment reveals alarming findings about the rapid rise in nitrous oxide (N₂O) emissions, highlighting its impact on climate change and human health. Released at the 2024 United Nations Climate Change Conference (COP29) in Baku, Azerbaijan, the assessment, published by the United Nations Environment Programme (UNEP) and the Food and Agriculture Organization (FAO), sheds light on the urgent need to control this potent greenhouse gas. As emissions surge beyond anticipated levels, scientists emphasize that swift and effective action is critical to safeguarding climate targets, the ozone layer, and public health.

Nitrous oxide, primarily emitted from agricultural sources like synthetic fertilizers and manure, is approximately 270 times more potent than carbon dioxide in warming the planet. Although it accounts for around 10 percent of global warming effects since the industrial era, it is the leading ozone-depleting substance currently being released into the atmosphere.

Its harmful effects on the ozone layer and its function as a potent greenhouse gas create a complex challenge for climate mitigation and environmental protection. The Assessment outlines that the unchecked release of N₂O could expose significant portions of the global population to dangerous UV radiation, leading to an increase in skin cancers, cataracts, and other health risks.

The report warns that without concerted efforts to curb N₂O emissions, there is little hope of limiting global temperature rise to 1.5°C, a target outlined in the Paris Agreement as essential to avoid severe climate impacts. The Assessment suggests that with proactive measures, emissions could be reduced by over 40 percent, providing a realistic pathway to meeting critical climate goals.

Specifically, it notes that if N₂O emissions are managed efficiently, it could prevent up to 235 billion tonnes of CO₂-equivalent emissions by the end of the century, an amount comparable to six years of current global CO₂ emissions from fossil fuels.

One of the significant contributions of the Assessment is its detailed roadmap for reducing nitrous oxide emissions across sectors. Transforming agricultural practices, optimizing nitrogen use, and reducing excessive nitrogen application are emphasized as crucial steps toward controlling emissions.

David Kanter, Associate Professor of Environmental Studies at NYU and Co-Chair of the Assessment, highlighted that effective N₂O management is vital for long-term climate stability. He added that reducing N₂O emissions by this margin would equate to avoiding the release of six years’ worth of fossil fuel-derived CO₂, highlighting the immense climate benefits of aggressive N₂O reduction.

Reducing N₂O emissions offers additional benefits beyond climate protection. By managing nitrogen compounds more sustainably, it is possible to improve air quality, preserve soil health, and protect ecosystems from the adverse effects of nitrogen runoff.

A.R. Ravishankara, atmospheric scientist and Co-Chair of the Assessment, underlined that sustainable nitrogen management not only reduces nitrous oxide emissions but also mitigates the release of other harmful nitrogen compounds, enhancing air and water quality and fostering a healthier environment. Importantly, these measures would simultaneously contribute to food security, helping farmers produce more with fewer resources and reducing the overall environmental impact of agriculture.

The Assessment highlights that the chemical industry can quickly and cost-effectively reduce emissions, making it a viable starting point for decreasing nitrous oxide (N₂O) emissions. By addressing N₂O and related emissions, it is possible to prevent up to 20 million premature deaths by 2050 through improved air quality. With tangible solutions in place, the report strongly advocates for immediate action, framing N₂O reduction as part of a broader global initiative to tackle climate super pollutants.

Kaveh Zahedi, the Director of FAO’s Office of Climate Change, Biodiversity, and Environment, emphasized the importance of sustainable nitrogen use in agriculture. He highlighted that by enhancing nitrogen efficiency and reducing excessive nitrogen applications, countries can simultaneously achieve their climate and food security goals.

The Global Nitrous Oxide Assessment makes a compelling case for this multifaceted approach, positioning N₂O reduction not only as an environmental necessity but also as a solution for public health and food security.