Monitoring the Impact of Nature-Based Solutions on Carbon Sequestration in Wetland

In Switzerland, emissions from drained wetlands are estimated to be at least 0.8 Mt CO2 equivalent per year, but reliable data is scarce, and the real number corresponds to 5-8% of Swiss territorial GHG emissions. The restoration of wetlands by rewetting is a measure to curb CO2 emissions and restore the soil’s natural carbon sequestration capacity. This is a solution ready to be scaled up, as in Switzerland alone there are approximately 30’000 ha of drained wetlands are available for restoration. Private institutions can contribute to these restoration efforts by purchasing carbon credits issued by restoration projects on voluntary carbon-credit markets. These investment programs require that managers of recipient projects monitor the amount of carbon sequestered in their wetlands.

Although different monitoring frameworks exist, a low-cost methodology for in-situ measurements of changes in carbon stocks is still missing. There is thus a need for an improved methodology to quantify the mitigating effect of wetland restoration on climate change, incentivize restoration efforts, and determine necessary future investment into wetland restoration toward 2050 net-zero objective.

ABOUT THE PROJECT

The goal of the planned project is to: 
(i) provide a monitoring system to quantify the real-time effect of wetland restoration on carbon sequestration and GHG emissions (including CO2 and CH4);
(ii) develop updated guidelines for monitoring carbon sequestration during wetland restoration as well as tools to estimate the carbon sequestration capacity of Swiss wetlands.

To do that, EPFL scientists will characterize and assess two study sites, i.e., a small wetland (humid biotope) on EPFL campus and a large wetland currently being restored in Switzerland. We will then use advanced sensors and flux towers to measure the carbon fluxes in these sites. We will also develop a model simulating such fluxes and feed it with ground measurements to complete our estimates. Finally, we will use remote-sensing technologies to correlate our ground measurements with remote-sensing information (e.g., satellite images) and generalize further our results for areas where sensors cannot be deployed.

Our long- term goal is to provide a scientific basis to increase the monitoring and traceability of carbon sequestration via wetland-restoration projects and thus increase the investments into these solutions, in Switzerland and beyond.