A CO2 sequestration site is evaluated by incorporating a consistent petrophysical framework having uncertainties expressed in the form of probability density functions of wellbore measurements, by systematically propagating the uncertainties in generating probability density functions or cumulative distribution functions of the parameters used in a reservoir simulation, by using the reservoir simulation to transform the first set of parameters into output variables with uncertainties, and by using the output variables and uncertainties to generate an answer product from which uncertainty levels of performance metrics can be ascertained.