Top panel A: surface temperature of the planet calculated as a function of the effective flux S_eff, defined as the stellar flux received by the planet relative to present-day Earth solar flux, for four distinct total water contents (0.1, 1, 10 and 100 times the Earth ocean water content). Bottom panel B: runaway greenhouse temperature (T_ϵ) as a functionof the total water content. Our best fit is obtained for T_ϵ(Wc) = 80 + 700 + 1700, with Wc thewater content in Earth ocean water content units.