The Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6), completed in 2022, provides the most authoritative synthesis of N₂O science and policy options. Its findings paint a complex picture: N₂O mitigation is essential but underemphasized in current climate commitments.
Key Physical Science Findings (WGI)
The AR6 WGI report confirms that atmospheric N₂O concentrations reached 332.1 ppb in 2019 (since updated further), with a GWP₁₀₀ of 273. N₂O contributes approximately 0.1 W/m² of radiative forcing — about 6% of total anthropogenic forcing. The report expresses high confidence that this forcing will continue growing under all emissions scenarios that do not specifically target N₂O reductions.
N₂O radiative forcing: ~0.1 W/m²
Required 2030 reduction (1.5°C path): ~18%
Mitigation potential (agriculture): 0.6–1.6 GtCO₂e/yr
Cost-effectiveness: $0–100/tCO₂e
Mitigation Findings (WGIII)
The AR6 mitigation volume identifies agricultural N₂O reduction as one of the highest-potential, lowest-cost climate solutions. Measures including improved fertilizer management, nitrification inhibitors, and precision agriculture could collectively deliver 0.6–1.6 GtCO₂e/yr of mitigation by 2030 — at costs ranging from zero to $100/tCO₂e, making many options cost-competitive with or superior to energy-sector mitigation.