Drainage has turned peatlands from a carbon sink into one of the world's largest greenhouse gas ( GHG ) sources from cultivated soils. We analyzed a unique data set (12 peatlands, 48 sites and 122 annual budgets) of mainly unpublished GHG emissions from grasslands on bog and fen peat as well as other soils rich in soil organic carbon ( SOC ) in Germany. Emissions and environmental variables were measured with identical methods...