Sustainability and Uncertainty: Bottom-Up and Top-Down Approaches

Abstract

"The widely used concept of sustainability is seldom precisely defined, and its clarification involves making up one’s mind about a range of difficult questions. One line of research (bottom-up) takes sustaining a system over time as its starting point and then infers prescriptions from this requirement. Another line (top-down) takes an economical interpretation of the Brundtland Commission’s suggestion that the present generation’s need-satisfaction should not compromise the need-satisfaction of future generations as its starting point. It then meas- ures sustainability at the level of society and infers prescriptions from this requirement. These two approaches may conflict, and in this conflict the top-down approach has the upper hand, ethically speaking. However, the implicit goal in the top-down approach of justice between generations needs to be refined in several dimensions. But even given a clarified ethical goal, disagreements can arise. At present we do not know what substitutions will be possible in the future. This uncertainty clearly affects the prescriptions that follow from the measure of sustainability. Consequently, decisions about how to make future agriculture sustainable are decisions under uncertainty. There might be different judgments on likelihoods; but even given some set of probabilities, there might be disagreement on the right level of precaution in face of the uncertainty."