DOI
doi.org/10.1016/0921-8009(95)00048-8

Summary
This paper attempts to separate the definition of sustainability (which is argued to be quite straightforward) from related issues concerning: (1) which system, subsystem, or characteristics are to be sustained; (2) for how long they are to be sustained; and (3) when we can assess whether the system has actually been sustained. We argue that because we can only assess sustainability after the fact, it is a prediction problem more than a definition problem. We also propose that in order for evolutionary adaptation to occur, there must be an ordered, hierarchical relationship between the expected (finite) life spans of systems and their space and time scales.

Relevance for Complex Systems Knowledge
This is an old (1993), but seminal, paper on sustainability and systems. The point of departure is the critique against sustainability as a vague concept. The approach the is to explain sustainability from a systemic perspective and with specific attention to temporality and longevity. Further it notes that sustainability can only be determined after the fact. As a consequence, what passes as definitions should instead be considered as uncertain predictions.

The article continues with the question "what system or subsystem or characteristics of these systems one is interested in sustaining"? The response is that it would be desirable to reach consensus on the following:

 (1) a sustainable scale of the economy relative to its ecological life-support system;

(2) an equitable distribution of resources and opportunities
between present and future generations; and

(3) an efficient allocation of resources that adequately accounts for natural capital.

The argumentation around time scale is paticularly interesting.
"Evolution cannot occur unless there is limited longevity of the component parts so that new alternatives can be selected. And this longevity has to be increasing hierarchically with scale ..... Larger systems can attain longer life spans because their component parts have shorter life spans which allows the system to adapt to changing conditions. But without "death" at the lower scale, there can be no evolutionary change at the higher scale. Sustaining life requires death."

Point of Strength
The article provides interesting food for thought to be used in any education program discussing sustainability. Discussing sustainability from a systems and subsystems perspective,  and with the temporal aspects in mind provides a good frame for further debates and approaches to sustainability.