Scotland's cultivated topsoils are rich in carbon with a median soil organic carbon (SOC) content of ca. 3.65%. The storage of carbon in soil is a means to offset GHG emissions, but equally carbon losses from soils can add to these emissions. We estimate the amount of carbon stored in Scottish cultivated mineral topsoils (246 ± 9 Mt), the potential carbon loss (112 ± 12 Mt) and the carbon storage potential of between 150 and 215 Mt based on national-scale legacy data with uncertainty around the estimate due to error terms in predicting bulk densities for stock calculations. We calculate that Scotland's mineral cultivated topsoils hold the carbon equivalent of around 18 years of GHG emissions (based on 2009 emissions from all sources). We also derive a theoretical carbon saturation potential using a published, linear relationship with the