Fig. 3: Reconstructed the atmospheric concentration of carbon dioxide (pCO2) and temperature estimates over the past 18 Ma.
From: Continuous sterane and phytane δ13C record reveals a substantial pCO2 decline since the mid-Miocene
a pCO2 estimations based on the δ13C records of phytane (green circle, with closed symbols for Site DSDP 467, open symbols for additional sites), alkenones (peach squares), and the weighted average of steranes (lavender triangle). Error bars represent the one standard deviation based on Monte Carlo simulations that compound uncertainties for all input parameters. Previously compiled pCO2 estimations7 in diamond, alkenones (peach) and boron (teal). b Changes in UK′37-based mean annual sea surface temperature (SST) relative to modern10 high-latitudes for the Northern Hemisphere (NH, blue), mid-latitudes (30-50°) for the NH (cyan) and Southern Hemisphere (SH, green), and tropics (30 °N-30 °S, red). Compiled δ18O derived from benthic foraminifera54 (lavender) indicate bottom water temperature and build-up of continental ice volume. Source data are provided with this paper (Supplementary Data 1–9) or references therein.
