Pure CO₂ Earth magma ocean simulation with 14.7 TO of initial CO₂ mass following Elkins-Tanton (2008) and using the RT atmosphere model (solid black line). Two RT thermal emission grid lines for p_surf = 655 bar (blue solid line) and p_surf = 4122 bar (orange solid line) are shown, respectively, as specified in Sect. 2.5. The corresponding thermal emission for the gray atmosphere model as used in Elkins-Tanton (2008) is shown for comparison (dashed lines). The thermal emission deviates between the RT and gray atmosphere model by up to two orders of magnitude during the magma ocean stage in this case with T_surf = 1500-3000 K.