Restoring drained wetlands is a widely recognized strategy to mitigate climate change. Rewetting helps protect soil carbon and reduce carbon dioxide (CO₂) emissions. However, wetter conditions can also increase methane (CH₄) emissions, a potent greenhouse gas, potentially offsetting climate gains. To address this trade-off, we improved the LPJ-GUESS ecosystem model by incorporating high-affinity CH₄ oxidation—microbial processes that consume methane when soils are less saturated.

We applied this enhanced model to a Danish peatland and simulated 17 years (2007–2023) of CO₂, CH₄, and subsurface oxygen. The model captures both methane production and oxidation and shows that the site acts as a long-term CO₂ sink but also emits methane. Importantly, our analysis reveals that maintaining the water table about 9 cm below the surface offers the best climate outcome—cutting CH₄ emissions by 50% while sustaining carbon storage. This results in the lowest net greenhouse gas impact compared to fully saturated conditions.

Our findings highlight the need for site-specific rewetting strategies that account for microbial activity and water table dynamics. By improving how models simulate CH₄–O₂ interactions, we can better guide wetland restoration to deliver maximum climate benefits with minimal methane trade-offs.