A startling report by the United Nations Environment Programme (UNEP) has spotlighted nitrous oxide (N₂O) as a silent but potent force accelerating climate change and depleting the ozone layer.
Stakeholders at a climate summit in Baku, Azerbaijan, dubbed it the “forgotten super pollutant,”. The N₂Occounts for 10% of net global warming since the industrial revolution, yet remains under-addressed in climate discussions.
The Global Nitrous Assessment, launched at the summit, reveals that nitrous oxide is 270 times more potent than carbon dioxide (CO₂) in trapping heat in the atmosphere. Primarily emitted from synthetic fertilizers and manure, it ranks as the third most significant greenhouse gas and the leading ozone-depleting substance.
“A sustainable nitrogen management approach not only reduces nitrous oxide emissions but also prevents the release of other harmful nitrogen compounds,” said A.R. Ravishankara, co-chair of the assessment and atmospheric scientist at Colorado State University.
Ravishankara highlighted the potential benefits for air quality, ecosystem health, and food security with improved nitrogen practices.
The report warns that without global efforts to transform food production and rethink nitrogen management, N₂O emissions will continue to undermine climate action. It proposes a 40% reduction in emissions through existing abatement technologies and sustainable agricultural practices.
Meanwhile, headof the UNEP-convened Climate and Clean Air Coalition, Martina Otto stressed the urgency of addressing nitrous oxide:
“By using the tools highlighted in this assessment, we can yield multiple benefits across climate, clean air, and public health.”
The timing of the report is critical.
2024 has seen record-breaking greenhouse gas emissions and rising global temperatures, intensifying calls for decisive action at COP29. The summit, which has already drawn criticism for the presence of over 1,700 fossil fuel lobbyists, now faces heightened pressure to address overlooked pollutants like N₂O.
Environmental advocates stress that tackling nitrous oxide emissions requires global cooperation, particularly from agriculture-heavy economies. With food systems contributing significantly to emissions, transforming farming practices has become a priority for both developed and developing nations.
The report also underscores how N₂O interacts with other climate drivers. Increased emissions exacerbate ozone depletion while influencing methane and aerosol levels in the troposphere. UNEP highlights that changes in N₂O levels occur over centuries, making immediate action crucial to mitigate long-term effects.
Africa, which faces disproportionate climate impacts, is taking note of the findings. Nigerian climate activist organizations are calling for policy reforms to regulate fertilizer use and promote organic farming methods. “We need to localize solutions to address this silent threat while safeguarding food security,” said environmentalist Nnimmo Bassey.
Some countries are already stepping up. The European Union has introduced initiatives to reduce synthetic fertilizer dependency, while African nations like Kenya are exploring bio-fertilizers to minimize emissions. However, global agricultural giants remain under pressure to adopt sustainable practices on a larger scale.
Critics argue that nitrous oxide has long been overlooked because it lacks the immediacy of CO₂ and methane. “N₂O may not dominate headlines, but its impact is profound,” said Otto. “We must integrate its mitigation into broader climate strategies.”
As negotiations at COP29 continue, UNEP’s findings serve as a reminder that tackling climate change requires addressing all major greenhouse gases. Delegates are pushing for robust frameworks to include N₂O reduction strategies in national climate action plans.
The report is not just a wake-up call but a roadmap for integrating science, policy, and innovation to curb emissions. With millions of lives and ecosystems at stake, the world’s response to nitrous oxide will be a defining test of global climate commitment.
