Securing funding for a peatland restoration project will typically require estimation of the reduction in emissions and/or sequestration arising from the change in management. Different approaches are available to undertake this that vary in their rigour and cost. Quantification with a view to establishing a formally recognised and validated carbon credit scheme will require considerable certainty in estimation, however, less onerous methods are available that may well be ‘accurate enough’ to lead to investment. Regardless of the method used, an estimate of baseline (current situation) and future emissions (under restoration) is likely to be required.

Reference Scenario

To determine a decrease in GHG emission or a change in any other ecosystem service, after a land use change, it is important to formulate the baseline scenario or reference. If a rewetted area was used for conventional drainage-based agriculture for example, the drop in GHG emission can be much larger than in a situation where the land was previously used extensively (Liu et al., 2023).

Since the chosen reference scenario plays a big role in determining the eventual improvement in ecosystem services and GHG emissions that can be credited, it is an important factor determining the profitability of a change in land-use.

Apart from the reference scenario, it is also important to consider the alternative future scenario. What would have happened with the area if it would not have been rewetted? Perhaps partial rewetting was planned already, or a more extensive use of the area was planned. The gain from full rewetting is then only the difference between partial and full rewetting. An important side note however, is that this ‘future reference’ can never be verified and carries a large uncertainty. Changes in the economy or public opinion might have influenced the future of a certain area. It is thus important to be careful and conservative when using future reference scenarios (Joosten et al., 2015).

A more costly approach that can be applied to smaller research projects, is that of long-term monitoring of a reference area. In this case, a reference area that does not undergo rewetting is compared to a rewetted area. They are both monitored on a longer time scale to determine the changes occurring due to rewetting. An important sidenote is the fact that the reference site in this case does not undergo spontaneous development that other areas might experience since it is labelled as a reference site and thus must remain stable (Joosten et al., 2015).

Taken together it is important to formulate a clear reference scenario, formulate the planned changes and likely gains that come with that, and then verify these gains by monitoring in the future to ensure correct payment for improvements in ecosystem services and GHG emission reductions.

Water Quality, Storage, and Flood Prevention

To assess water quality, the levels of nitrogen (N) and phosphorus (P) are most important. High quality information on the nutrient balance in and around peatlands can be gained through long-term measurements adapted to local hydrology (Trepel, 2004). This approach is very costly and cannot be done beforehand. Alternatively, complex modelling can be used, considering local hydrology and internal processes (Trepel, 2004). A very conservative approach based on vegetation type (NEST approach) is the cheapest and easiest way of assessing changes in water quality (Joosten et al., 2015).

Hydrodynamic modelling can be used to calculate the retention potential and associated flood peak reduction of peatlands. An initial assessment of the long term groundwater storage in rewetted peatlands can be done using available maps, digital data and some field visits. A more detailed assessment requires information on all involved aquifers and a long time series of groundwater data. This information is then fed into a geo-hydraulic model, which can predict the effects of rewetting (Joosten et al., 2015).

Monitoring in Carbon Connects Pilot Sites

Memo on the pilot sites at baseline.

Read the monitoring report from the Outgherard pilot site in Ireland.

Read the monitoring report from the Valance Lodge pilot site in the UK

Read the monitoring report from the Grand Lieu pilot site in France

Read the monitoring report from De Blankaart and Kwetshage pilot sites in Belgium

Read the monitoring report from the Helmond pilot sites in the Netherlands

Read the report from Verbruggen pilot site on Growing oyster mushrooms on cattail