3. Systems science and societal choices

Since the 1980s, scientific fields such as ecological economics and model-based integrated environmental assessment (IEA) have addressed the interdependencies between the economic and environmental spheres, characterised on the interface by, on the one hand, environmental pressures and, on the other hand, environmental functions/services. Governance on this interface seeks to ensure a double performance criterion: (1) economic welfare through production of economic goods and services as emphasised in traditional economics, and (2) the permanence of an ecological welfare base through assuring maintenance of environmental functions.

For integrated analyses of sustainability challenges, societal options can be framed in a comparative scenario context for the exploration of the ‘‘ecological-economic space of opportunities’’ for society into the future. This means to explore, within the limits of what might be feasible, a range of alternative evolutions that, on various societal grounds, might be judged as more or less desirable, or undesirable. The Tetrahedral Model (Fig. 1) may, in this regard, be construed as the articulation of two complementary axes that together, portray ‘‘the problem of social choice’’.

• The first axis, feasibility is the “edge” composed of the interdependent ecological and economic spheres. This is the realm of systems science and integrated economy-environ­ment modelling.

• The second axis, desirability is the ‘‘edge’’ composed by the interference of the political and social spheres. This signifies the governance problem of institutional arrangements for coordination of the actors in society with their disparate interests and preoccupations.

The advantage of this framing is that it highlights the fundamental complementarity of, on the one hand, systems analyses with natural sciences foundations and, on the other hand, social sciences and humanities for the characterisation of what is good, just and acceptable(including for whom and why).