The Arctic is warming which may potentially affect substrate availability, organic matter decomposition, plant growth, and plant species composition. This may lead to changes in the exchange of methane (CH₄) and carbon dioxide (CO₂) between the soil system and the atmosphere. Yet the correlations among substrate availability, CH₄ production, and net emissions of CH₄ have been scarcely studied in arctic wetlands. Presently, the impact of increasing temperatures on CH₄ exchange is uncertain as the two existing reports on field warming in arctic wetlands present opposite results. We here report results on how summer warming and shrub removal affect soil water substrate (acetate, formate, oxalate, and dissolved organic carbon) concentrations as well as dissolved CH₄ and CH₄ emissions in a fen at Disko Island (West Greenland). The peak in dissolved CH₄ followed the peak in acetate concentration, and appeared after the peak in CH₄ emissions, which indicates a lack of correlation between CH₄ production and emissions. The peak in CH₄ emissions coincided with maximum gross ecosystem production suggesting that CH₄ emissions are closely linked to photosynthesis. This was supported by an experiment with removal of the sedge Carex aquatilis ssp. stans which contributed with up to 77% of the CH₄ emitted from the ecosystem. By contrast, shrub removal and summer warming did not significantly affect CH₄ emissions, possibly due to the treatments impacting CH₄ production more than emissions. This implies that such wetlands may be less sensitive to moderate warming and changes in shrub cover than previously assumed.