Figure 7.

(A) Benthic δ¹⁸O [Lisiecki and Raymo, 2005] and (B) change in global average surface temperature (ΔGAST) [Snyder, 2016] compared with (C) pCO₂ derived from ice cores [Bereiter et al., 2015; Higgins et al., 2015] and boron isotope reconstructions [Hönisch et al., 2009; Seki et al., 2010; Bartoli et al., 2011; Henehan et al., 2013; Martínez-Botí et al., 2015a; Chalk et al., 2017]. Published pCO₂ records have been recalculated using consistent methods (see Methods) from the original δ¹¹B data. Late Pleistocene boron-based pCO₂ records from Sites 999A and 668B are in the same range as ice-core-based pCO₂ measurements. The largest resulting difference is the record of Bartoli et al. [2011], to which new temperature data have been applied and pCO₂ is calculated by pairing pH with alkalinity estimates rather than [CO₃^2-].