Hydrogen escape and outgassing rates as a function of redox state of the mantle for scenario 2.2 (EOM). The solid red line shows the H₂ outgassing rate at the end of magma ocean. The closed red circles show the diffusion-limited escape of H₂ for the EOM. The shaded region in yellow shows the loss rate due to energy-limited escape within the range S = 10 (lower boundary) to S = 100 (upper boundary) i.e. XUV relative to the modern value. The vertical dotted line marks the region separating a high H₂ VMR to low H₂ VMR and illustrates the most efficient escape process occurring. The present Earth H₂ degassing rate with an uncertainty range (Ramirez et al. 2014) is marked for reference.