Response to Gallagher (2022)—the Australian Tidal Restoration for Blue Carbon method 2022—conservative, robust, and practical

The Blue Carbon Accounting Model (BlueCAM) is a tool for tidal restoration projects established under the Tidal Restoration for Blue Carbon method (2022) of the Australian voluntary carbon market. The commentary of Gallagher discussed that BlueCAM did not subtract allochthonous carbon, which is carbon in wetland soils from external sources, either terrestrial or marine sources, from estimated net abatement. This approach was used because all organic carbon preserved in a restored wetland soil, irrespective of its source, is deposited because the wetland was restored, and thus all carbon preserved above the baseline is “additional.” As restoration projects develop, further characterization of different soil carbon fractions as suggested by Gallagher may improve BlueCAM. BlueCAM is transparent, conservative, and importantly is feasible for implementation, as well as being consistent with the Intergovernmental Panel for Climate Change guidelines for National Greenhouse Gas Inventories and the Australian legislative offsets integrity standards.