Extended Data Figure 2: LIG greenhouse gases, orbital parameters, and RCM climates.
From: Contribution of Antarctica to past and future sea-level rise
a, Greenhouse gas concentrations9,72 converted to radiative forcing shows the LIG interval (light red bar) and the best opportunity for ice-sheet retreat. b, Summer insulation at 70° latitude in both hemispheres73 (red, south; blue, north) and summer duration at 70° S (black)79 shown over the last 150 kyr, and the two orbital time slices (vertical dashed black lines at 128 kyr ago and 116 kyr ago). c, Table showing the greenhouse gas atmospheric mixing ratios (CO2 in parts per million by volume; CH4 and N2O in parts per billion by volume) and orbital parameters (eccentricity, obliquity, precession) used in the GCM–RCM at the LIG time slices (dashed lines 1 and 2 in a and b), respectively. d–f, January (warmest monthly mean) differences in 2-m surface air temperature relative to a preindustrial control simulation at 128 kyr ago (d), 116 kyr ago (e), and the present-day (2015) (f). Simulated austral summer temperatures at 116 kyr ago (e) with relatively high-intensity summer insolation is warmer than the long-duration summer orbit at 128 kyr ago (d), but unlike the Pliocene (Extended Data Fig. 1a), neither LIG climatology is as warm as the present day, producing little to no rain or surface melt on ice-shelf surfaces.
