Extended Data Fig. 9: Histograms showing the number of samples by CO₂ value during two distinct periods of 950 and 1,500 ka.

The values were estimated by the δ¹³C_FA at Site U1446 (CO₂^FA), blue ice^13,14, foraminiferal δ¹¹B (ref. ⁸), alkenone δ¹³C (ref. ⁹), pedogenic carbonate δ¹³C (ref. ¹⁰) and C₃ plant δ¹³C (ref. ¹¹).