Climate Mitigation Potential of Peatland Restoration in Switzerland 

Peatlands are among the most carbon-dense terrestrial ecosystems, accumulating organic carbon over millennia. Alongside essential ecosystem services such as biodiversity support, water purification, and erosion control, peatlands play a crucial role in climate regulation through long-term carbon sequestration and methane emissions. Over the past three centuries, widespread drainage of northern peatlands for agriculture, forestry, and urban expansion has led to severe ecosystem degradation.In Switzerland, despite the constitutional peatland protection introduced by the “Rothenthurm initiative” in 1987, most peatlands remain drained and continue to act as significant net carbon sources with substantially compromised ecosystem services. Restoration through rewetting is considered a high-impact nature-based solution, halting soil carbon losses and reinstating peatland functions as net carbon sinks. While carbon credits offer a pathway to mobilise private finance, current frameworks typically rely on generalised estimates with large uncertainties, and the restoration potential of avoided emissions at national scales remains poorly constrained. Field surveys and observations are essential for designing site-specific restoration measures and evaluating outcomes, whereas process-based modelling provides a complementary approach to assess peatland greenhouse gas exchanges under the changing climate across spatiotemporal scales.In this study, we employ the terrestrial biosphere model LPX-Bern to simulate greenhouse gas dynamics of Swiss peatlands from the preindustrial period to the present day. Carbon uptake and methane emissions from natural peatland processes are modelled under historical climate forcings. Peatland degradation resulting from land use conversion is represented by altered vegetation composition and water table level. By combining model simulations with empirical emission factors derived from field measurements under different land managements, the greenhouse gas balance of Swiss peatlands and their potential climate feedback under restoration can be evaluated. We highlight the urgent need for integrated assessment frameworks that link modelling and field investigations to robustly quantify the climate mitigation potential of peatland restoration. This work provides a process-based estimate of peatland restoration potential in Switzerland, informing climate mitigation strategies and supporting investment in large-scale peatland and wetland climate action.