Global agricultural N₂O emission reduction strategies deliver climate benefits with minimal impact on stratospheric O₃ recovery

Agricultural nitrous oxide (N₂O) emission reduction strategies are required given the potency of N₂O as a greenhouse gas. However, the growing influence of N₂O on stratospheric ozone (O₃) with declining stratospheric chlorine means the wider atmospheric impact of N₂O reductions requires investigation. We calculate a N₂O emission reduction of 1.35 TgN₂O yr⁻¹ (~5% of 2020 emissions) using spatially separate deployment of nitrification inhibitors ($70–113 tCO₂e⁻¹) and crushed basalt (no-cost co-benefit) which also sequesters CO₂. In Earth System model simulations for 2025–2075 under high (SSP3-7.0) and low (SSP1-2.6) surface warming scenarios, this N₂O mitigation reduces NOx-driven O₃ destruction, driving regional stratospheric O₃ increases but with minimal impact on total O₃ column recovery. By 2075, the radiative forcing of the combined N₂O and CO₂ reductions equates to a beneficial 9–11 ppm CO₂ removal. Our results support targeted agricultural N₂O emission reductions for helping nations reach net-zero without hindering O₃ recovery.

James Weber, James Keeble, Nathan Luke Abraham, David J. Beerling, Maria Val Martin