Near-surface permafrost degradation: How severe during the 21st century?

[1] A previously presented model on nearly complete near-surface permafrost degradation in the Arctic during the 21st century is critically reviewed. An alternative model with a more complete mathematical formulation of the physical processes acting in permafrost terrain is presented, which suggests that permafrost will mostly prevail in this century in areas north of 70°N. Furthermore, permafrost will survive at depth in most areas between 60° to 70°N. Based on paleoclimatic data and in consequence of this study, it is suggested that scenarios calling for massive release of methane in the near future from degrading permafrost are questionable.