Equilibrium global temperature and CO₂ partial pressure for an Earth-like planet as a function of time with land-based and seafloor weathering, with W_L0 = 1/3 and W_S0 = 2/3. The outgassing rate is either fixed at the current rate for Earth (red curves) or decays exponentially with an initial value G₀ = 5 times the current rate (blue curves). Note that the two cases are identical for the first 2.9 Gyr.