Calculations of the surface temperature of the Earth with a water vapor canopy, under the assumption of radiative equilibrium, yield temperatures too high for life to exist. Moreover, when the results about radiation are combined with the barometric law, only certain solutions to the physical description of the canopy are found to be possible for a given set of assumptions; and those solutions generally lead to impossible environmental conditions or else do not fulfill the purpose for which the canopy was proposed. It appears that some new thinking about the antediluvian climate, and the cause of the Flood, is due.