Rewetting strategies to reduce nitrous oxide emissions from European peatlands

Abstract

Nitrous oxide (N₂O) is approximately 265 times more potent than carbon dioxide (CO₂) in atmospheric warming. Degraded peatlands are important sources of N₂O. The more a peat soil is degraded, the higher the N₂O-N emissions from peat. In this study, soil bulk density was used as a proxy for peat degradation to predict N₂O-N emissions. Here we report that the annual N₂O-N emissions from European managed peatlands (EU-28) sum up to approximately 145 Gg N year⁻¹. From the viewpoint of greenhouse gas emissions, highly degraded agriculturally used peatlands should be rewetted first to optimally reduce cumulative N₂O-N emissions. Compared to a business-as-usual scenario (no peatland rewetting), rewetting of all drained European peatlands until 2050 using the suggested strategy reduces the cumulative N₂O-N emissions by 70%. In conclusion, the status of peat degradation should be made a pivotal criterion in prioritising peatlands for restoration.

Rewetting agricultural peatlands first is the best strategy for reducing cumulative nitrous oxide emissions from European peatlands, according to an analysis of soil bulk density as a proxy for peat degradation.