Ecological cost replaces the monetary reading of cost with the real one. Every undertaking consumes some combination of material resources, energy, human attention, physical health, time, emotional load, environmental capacity, institutional attention, trust, social coordination, opportunity, and future flexibility — and money captures only a slice of it. A project that “costs” $10 million may have a small ecological cost; another at the same price may leave behind exhausted people, damaged land, monopolized knowledge, community distrust, and decades of maintenance. Same figure, entirely different draw-down.
Why it comes first
Before asking whether an activity produces ecological growth, the model asks what it actually consumes — what does this draw down? — which is the beginning of real renewability accounting and the thing that makes hidden depletion visible. It is also how the model detects cost that has merely been externalized: a system that looks efficient only because someone else is carrying the depletion has not lowered its ecological cost, only moved it off its own books. See Renewability.