Table 3 Adjusted coefficients of determination (R2) between the observed and predicted values for mean annual ground temperature (MAGT) and active layer thickness (ALT) models in baseline and past conditions (hindcast).

From: Circumpolar permafrost maps and geohazard indices for near-future infrastructure risk assessments

Period

MAGT R2

MAGT uncertainty ( ± , °C)

ALT R2

ALT uncertainty ( ± , cm)

Permafrost extent with uncertainty (106 km2, ± )

Hindcast (1970–1984)

0.90

0.76

—

—

—

Hindcast (1985–1999)

0.93

0.77

0.57

37

—

Baseline (2000–2014)

0.95

0.77

0.37

37

15.1 (13.0–17.2)

RCP2.6 (2041–2060)

 

0.85

 

38

10.0 (8.2–12.2)

RCP4.5 (2041–2060)

 

0.86

 

38

9.1 (7.5–11.2)

RCP8.5 (2041–2060)

 

0.90

 

39

8.0 (6.2–9.8)

RCP2.6 (2061–2080)

 

0.85

 

38

9.9 (8.0–12.0)

RCP4.5 (2061–2080)

 

0.90

 

39

8.0 (6.3–9.9)

RCP8.5 (2061–2080)

 

0.98

 

42

5.4 (3.6–7.3)

  1. Uncertainty values were determined also for both future periods under three emission trajectories (RCP, representative concentration pathway). MAGT evaluation was performed for model ensemble predictions, whereas ALT evaluation was based on GLM (generalized linear modelling) alone. Uncertainty ranges for permafrost extents were calculated using uncertainty values from MAGT predictions.
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