Environmental sustainability: issues of definition and measurement.

Operationalisation of the concept of sustainable development requires the formulation of sustainability indicators and of techniques to assess scores on such indicators. A flexible approach is proposed, which incorporates several normative issues (including intergenerational welfare and substitution of manufactured capital for natural capital) and leads to a choice of location–specific sustainability constraints. Key parameters include classes of environmental resources, threshold levels, spatial level and time path. Assessing the score on this sustainability indicator involves the measurement of the difference between actual and normative levels of resource use. Depending on the measurement scale at which information becomes available, multi–criteria analysis may be useful to arrive at overall sustainability scores.