Sustainable Scale: Throughput Less Then Regeneration
One or the Other: Sustainable or Unsustainable
The amount of throughput in the global economy is either sustainable or unsustainable. All economic throughputs degrade ecosystems to some extent; the key issue is whether the rate or total amount of throughput is greater than the natural regeneration of affected ecosystem functions. If the impact of economic throughput degrades ecosystems faster than they can regenerate, there is an inevitable loss of ecosystem functions; this is unsustainable.
If the impact allows the ecosystems to totally replace the resource or sink functions it interferes with, then there is no loss of function and they can endure; this is a sustainable scale. Economic throughput either degrades ecosystems faster or slower than they can regenerate; it draws down either more or less natural capital than ecosystems reproduce. This is a basic feature of ecological sustainability. Whether or not economic activities are sustainable (in terms of the ecosystems that contain and sustain them) has only become a relevant policy issue as evidence accumulates that current levels of economic throughput have crossed the sustainability threshold, and are continuing to increase (see Brief Overview
, and Areas of Concern