Dependence of the evolution of carbon dynamics in the northern permafrost region on the trajectory of climate change

All models simulating carbon represented soil with depth, a critical structural feature needed to represent the permafrost carbon-climate feedback, but that is not a universal feature of all climate models. Between 2010 and 2299, simulations indicated losses of permafrost between 3 and 5 million km(2) for the RCP4.5 climate and between 6 and 16 million km(2) for the RCP8.5 climate.

For the RCP4.5 projection, cumulative change in soil carbon varied between 66-Pg C (10(15)-g carbon) loss to 70-Pg C gain. For the RCP8.5 projection, losses in soil carbon varied between 74 and 652 Pg C (mean loss, 341 Pg C). For the RCP4.5 projection, gains in vegetation carbon were largely responsible for the overall projected net gains in ecosystem carbon by 2299 (8- to 244-Pg C gains).