What We Talk About When We Say "Sustainable"
I suspect most people learn words not by looking them up, but by fuzzily deriving their meaning from the contexts in which they appear.
My grandfather had an electric piano with a button labeled "sustain"; when activated, notes would linger longer than usual. As a non-native English speaker, that was for many years my only exposure to the word. As a result I thought that "to sustain" simply meant "to prolong."
As I became more environmentally aware, the meaning shifted from there to the product-oriented "make products that last longer" and, later still, to the process-focused "create a way of producing things that can continue for as long as the sun shines." I still haven't looked up the official definition, but ecologically speaking, that last definition sounds pretty good to me.
There are two ground rules that must be met for a production process to be sustainable:
- extract nothing from the environment faster than it regenerates
- create nothing that the environment cannot process and neutralize in a reasonable amount of time without side effects
The first rule ensures that we don't "use up the Earth" (as we've been doing since the early 1970s); the second guarantees we don't poison it. Both are necessary if future generations are to survive.
If sustainability truly means following those two rules, then it's used far more often in marketing than in reality.