Permafrost peatlands are biogeochemical hot spots in the Arctic as they store vast amounts of carbon. Permafrost thaw could release part of these long‐term immobile carbon stocks as the greenhouse gases (GHGs) carbon dioxide (CO 2 ) and methane (CH 4 ) to the atmosphere, but how much, at which time‐span and as which gaseous carbon species is still highly uncertain. Here we assess the effect of permafrost thaw on GHG dynamics u...