This paper analytically characterizes the four main environmental sustainability paradigms (i.e., WS, weak sustainability; AG, a-growth; DG, de-growth; and SS, strong sustainability) by introducing uncertainty about future preferences for consumption and future technologies. SS represents an ethical approach because of its maximum aversion to inter-generational inequality of resources, whereas DG depicts preference changes, AG depicts technology changes, and WS represents the reference paradigm without accounting for preference or technology changes. By comparing the costs and benefits of these paradigms, solutions derived for the whole parameter domains based on data for a globally representative individual suggest that whenever environmental sustainability is pursued for welfare reasons within a utilitarian perspective (i.e., WS, AG, DG), it is not worth pursuing. In contrast, if environmental sustainability is achieved for ethical reasons within an egalitarian perspective (i.e., SS), it is worth pursuing, even with an increased world population. In terms of feasibility (i.e., whether there are realistic parameter values such that a given sustainability paradigm can achieve its goal), solutions are ranked ethics > preference > technology (i.e., SS > DG > AG), whereas WS is unfeasible. Thus, WS, AG, and DG are inconsistent sustainability paradigms, SS empirically solves the theoretical dispute on absolute rights, and environmental sustainability must be treated as an ethical issue.