Sustainability indicators for anticipating the fickleness of human–environmental interaction

The development of environmental indicators is dominated by the so-called pressure–state–response (PSR) model. The PSR contains a set of indicators measuring anthropogenic pressure (P) on the environment, the state (S) of the environment resulting from such pressure, and the societal response (R) to ease the pressure. The strength of the PSR is its acknowledgement of the causal relationship between the state of the environment and human activity. Its major weakness, however, is the lack of sophistication of the mathematical and cognitive models representing the causal relationship. As a result, current indicator systems based on the PSR fail to take into account contingencies in human–environmental interaction that make the future state of the system difficult to ascertain. Recognizing the fickleness of human beings and nature will result in very different indicators from those traditionally developed. In particular, the article identifies the following important areas of indicator development: (1) indicators of ecosystem impacts of production, which measure changes in production outputs and environmentally significant inputs; (2) indicators of bounded carrying capacity, which utilize alternative scenarios of human–environmental interaction to specify the ecosystem-specific limits that societies might impose on industrial production; (3) indicators of congruence between ecosystems, institutions and production, which measure the agreement between the functions of an ecosystem and the institutional rules governing its management; and (4) indicators of technological and institutional path dependence, which observe and potentially strengthen lock-ins in human–environmental interaction. These development challenges imply that sustainability indicators should be considered more as vehicles for improving communication between different communities of experts on the sustainability of a particular system of human–environmental interaction, and less as universal measures of sustainability.