Around 4% of global greenhouse gas (GHG) emissions originate from drained peatlands. Unlike rewetting drained peatlands with freshwater, brackish water rewetting is expected to reduce CO 2 emissions, while keeping post-rewetting methane (CH 4 ) emissions low. Sulfate-containing brackish water should favor sulfate reduction and therefore limit CH 4 production and/or lead to increased CH 4 consumption. Here, we compared CO 2 and...