Chadburn, Sarah; Burke, Eleanor J; Cox, Peter; Friedlingstein, Pierre; Hugelius, Gustaf; Westermann, Sebastian (2017): Estimated future permafrost maps constrained by observed relationships, with link to model result files in NetCDF format [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.873192,

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Supplement to: Chadburn, S et al. (2017): An observation-based constraint on permafrost loss as a function of global warming. Nature Climate Change, https://doi.org/10.1038/nclimate3262

A globally applicable relationship between air temperature and permafrost areal fraction was derived using reanalysis air temperatures and the historical IPA permafrost map. This relationship defines a maximum, minimum and mean permafrost fraction at a given air temperature. Future air temperatures were estimated for a particular global mean warming, using the observed Arctic amplification and a pattern-scaling approach with the 1986-2005 mean air temperatures as the baseline.

Here we show the estimated permafrost map, using our method, from the time of the IPA map ('historical' = 1960-1990), along with the estimated future permafrost maps using pattern-scaled air temperatures, for a range of global stabilisation temperatures (between 1 and 6 degree C above pre-industrial levels (1850-1900)). For each global mean air temperature there is a maximum, minimum and mean permafrost extent according to our permafrost-air temperature relationships.

The file naming is as follows: map_<deg><type>.nc, where <deg> is degrees of warming above pre-industrial climate, and <type> is one of max, min, or mean, indicating maximum, minimum or mean permafrost extent. The maps are global at 0.5 degree resolution.