Stopping the Leak and Rebuilding the Sink? Positioning Peatland Rewetting as a Climate Change Mitigation Measure

Peatland rewetting can reduce greenhouse gas (GHG) emissions (stopping the leak) and establish Carbon Dioxide Removals (CDR, rebuild the CO₂ sink). Emission reductions and CDR are two distinct climate change mitigation strategies that require tailored accounting methodologies and regulatory designs to ensure environmental integrity.

Here, we evaluate the potential, constraints and uncertainties of rewetting agriculturally drained peatlands as a strategy for emission reduction and CDR. Our analysis utilizes radiative forcing modeling and the sustained global warming potential (GWP*) metric, applied to emission factors from Germany’s national inventory reporting. Further, to account for the large variety of rewetting outcomes, we incorporate two emission trajectories in our evaluation: first, a worst-case scenario characterized by high initial CH₄ pulses and delayed CO₂ sequestration due to year-round flooding and, second, a best-case scenario, featuring low CH₄ emissions and high initial CO₂ sequestration associated with precise water table management and the rapid establishement of wetland vegetation. Furthermore, we quantify additional CDR gains derived from long-term carbon storage in products from paludiculture biomass and, finally, contrast peatland rewetting with alternative CDR techniques, highlighting its synergies in ecosystem services and biodiversity conservation.

Our findings contribute to the scientific basis for better integrating peatland rewetting into climate policies and accounting schemes, ensuring that regulatory frameworks most accurately reflect the climate change mitigation potential of rewetting agriculturally drained peatlands.