Permafrost peatlands are thawing due to climate change, releasing large quantities of carbon that degrades upon thawing and is released as CO₂, CH₄ or dissolved organic carbon (DOC). We incubated thawed Norwegian permafrost peat plateaus and thermokarst pond sediment found next to permafrost for up to 350 d to measure carbon loss. CO₂ production was initially the highest, whereas CH₄ production increased over time. The largest carbon loss was measured at the top of the peat plateau core as DOC.