Estimated effect of the permafrost carbon feedback on the zero emissions commitment to climate change

Abstract. Zero Emissions Commitment (ZEC), the expected change in global temperature following cessation of anthropogenic greenhouse gas emissions, has recently been assessed by Model Intercomparison Project (ZECMIP). ZECMIP concluded that component ZEC from CO2 emissions will likely be close to zero decades emissions. However, 18 Earth system models participated only 2 included a representation permafrost carbon feedback climate change. To better assess potential impact decay on ZEC, series perturbed parameter experiments are here conducted with an model intermediate complexity. The experiment suggests cycle directly add 0.06 [0.02 0.14] ?C benchmark value assesses 50 years after 1000 Pg C emitted atmosphere. An additional 0.04 [0 0.06] is added relative thaw-lag effect unaccounted for design. Overall I unlikely assessment decadal timescales; however, become more important over coming centuries.