Figure 6.

Changing δ¹⁸O concentrations in the NGRIP ice core are a proxy for air temperature over Greenland. Up is warmer in the graph, down is colder. The full amplitude of the change in mean annual air temperature between the ice age and the Holocene was about 20°C in Greenland. Since ice‐core records like this were first reconstructed (Dansgaard et al., 1993), it has been clear that the ice‐age climate had a fundamentally different mode and tempo than the Holocene. The x axis is in b2k‐calendar years (years before AD 2000). The δ¹⁸O data are from Rasmussen et al. (2014) and Seierstad et al. (2014). Timing of Dansgaard–Oeschger (D‐O) events (orange bars) is from Rasmussen et al. (2014); timing of Heinrich events (dashed lines) is from Hemming (2004).