Figure 2.4 Attribution graphic showing impacts of greenhouse gases (GHG), natural variability (NAT) and other drivers (OTH) on total Arctic temperature change (ALL) during three consecutive periods of the 20th century. NAT is taken in this study to include El Niño/Southern Oscillation effects, volcanic effects and dynamically-induced atmospheric variability such as the cold ocean-warm land. Results in black are from a subset of CMIP5 models found to be the ‘Best 6’; gray bars denote across-model ranges. Red boxes are based on observational data (HadCRUT4 = HadCRUT4 temperatures), with uncertainty ranges indicated by box width (Fyfe et al., 2013).