Extended Data Fig. 10: Estimates of CO₂ in various methods.

CO₂ values estimated by the δ¹³C_FA at Site U1446 (CO₂^FA) with a calibration error of 12 ppm, foraminiferal δ¹¹B (with 1σ interval; ref. ⁸ data after refs. ^5,6,7), alkenone δ¹³C (with the upper and lower estimates)⁹, pedogenic carbonate δ¹³C (ref. ¹⁰) and δ13C of C₃ plants¹¹ during the past 1.5 Myr.