Examining challenges and uncertainties associated with using water table management to reduce greenhouse gas emissions from grassland peat soils

Countries with significant areas of grassland on organic soils must accurately estimate the extents of these lands to estimate greenhouse gas (GHG) emissions from them. These areas are often targeted for management change to reduce emissions reported under the Land Use, Land Use Change and Forestry (LULUCF) sector in national GHG emission inventories. The present study aims to assess the extent of grassland on organic soils across the European Union (EU) and their associated GHG emissions and utilises a systematic review process to quantify the potential effectiveness of efforts to raise the water table level on such lands. Additionally, using Ireland as a case study, different scenarios that incorporate varied levels of water table management, together with the reported extent and classification of nutrient and drainage status of these lands, enable a broad range of GHG emissions to be estimated. If Ireland were to meet its target of reducing the management intensity of 80,000 ha of drained organic soil under grassland, emissions from these lands will potentially reduce by 590.44 kt CO 2 -eq yr −1 . It may be difficult to fully rewet these lands, so other scenarios were also considered to demonstrate the potential emission reductions associated with raising the water table level from the currently assumed deeply drained status to shallow drained or a combination of both shallow drained and rewetted status. These scenarios provide a framework to explore different pathways to meet emission reduction targets for countries with significant extents of grassland on organic soils.