Fig. 4: Evolution of simulated oceanic P contents and atmospheric pCO₂ along with reconstructed sea surface temperature (SST) over the last 11 Myr.

a Model results for P weathering rate. b Model results for silicate weathering rate. c Oceanic P content. Model result of the deep ocean box (solid line). The points are calculated from the P/Fe data of this study using a linear scale factor, with the modern oceanic P concentration calibrated at 3 μM⁸⁴. d Atmospheric pCO₂. Model result (solid line) compared with proxy data (open circles)⁶⁸. e Reconstructed SST¹ from different latitudes. In this study, a Monte Carlo method was employed by varying the P weathering flux and climate sensitivity. A 5% variation was introduced to the P weathering flux using a normal distribution, while climate sensitivity was adjusted within a range of 4–6 °C also using a normal distribution. An enhancement factor of P weathering was applied to this simulation (Scenario 1), which is shown in Supplementary Fig. 8. Other than the enhanced forcing factor for P weathering, the other forcings include uplift as fixed at modern levels.