ETC/ULS Report 10/2021 Carbon pools and sequestration potential of wetlands in the European Union

06 Oct 2021

Dania Abdul Malak, Ana I. Marín, Marco Trombetti, Sonsoles San Román

Wetland ecosystems as defined by the Ramsar convention host a wide variety of wetland habitats across terrestrial, coastal and marine environments. When in good condition, wetland habitats provide many societal benefits and values, among others, they play a crucial role in the carbon cycle because of their capacities to limit the availability of oxygen to soil microbes and decomposition of organic matter. Policies and practices do not sufficiently consider these interconnections and interdependencies in Europe yet due to the fragmented consideration of this ecosystem in their schemes.

The findings of this report argue that healthy European wetland habitats have an enormous capacity to contribute to carbon neutrality objectives in Europe. Across the wide array of European ecosystems they belong to, wetland habitats have a role in contributing to the carbon cycle. The most meaningful European wetland habitats to contribute to carbon storage include well-functioning salt marshes, healthy mires, bogs and fens as well as riparian, fluvial and swamp forests. Furthermore, when healthy, terrestrial wetlands namely mires, bogs and fens (where peatlands underly), followed by riparian, fluvial and swamp forests as well as inland marshes ensure a high carbon sequestration potential. If kept in a good condition or restored, the EU wetland related carbon stock capacity of their overall area in Europe (EU 27 and the UK) is estimated to be between 12 - 31 Gt CO2-eq, corresponding to an overall value ranging between 3 and 8 years of EU GHG emissions1. Whereas the Carbon sequestration potential of healthy EU Wetlands per year is calculated to range between 24 and 144 Mt CO2 eq yr-1 (24,352 and 14,3719 kt CO2 eq yr-1), being a quantity that contributes to “neutralising” between 1 and 4 % of the total GHG emissions registered in the EU27 and the UK (according to 2018 reference year for reported emission). These findings should trigger wetland conservation and restoration to become a high priority for the EU to support reaching climate neutrality by 2050. Climate reporting systems require Parties to report on anthropogenic emissions and removals of greenhouse gases which includes reporting heavily modified peatland habitats only partially and dominantly as a net carbon emitter. Using ecosystem-based approaches to managing reported peatland habitats and re-establishing their ecosystem functioning do transform many of them from climate ‘heaters’ (carbon net sources) into climate ‘coolers’ (carbon net sinks).