I rememer two distinct episodes in my life: when I first heard the word “sustainable”, and a few days later, when I was hit with the “wow” moment of understanding it. So simple! So elegant! It’s like a budget — if you spend (whatever) less than when you bring in, you can survive indefinitely. The ecological equivalent to Paul Graham’s “Ramen Profitable” — immortality depends on a positive life-sustainer flow.
This idea is indeed elegant, with one small flow. The second law of thermodynamics means that no process is really sustainable. In the case of Paul Graham’s “Ramen Profitable”, it doesn’t matter — it’s close enough to infinity that other issues (not negative cash flow) will cause the company to close if it doesn’t make it big fast enough. But for ecological processes, they’re finite. That’s reality.
So I would like to offer an alternative to discussion in terms of sustainability (which, like I indicated, is impossible). Let’s discuss processes in terms of “runway”. Again, this term derives from start-up thinking: the runway a company has is the amount of cash it has divided by the burn rate. By the time we reach the end of the runway, we have to “evolve or die” — find another process, or die out of insufficient resources. Oil has “runway”: how long we can keep without finding a way to use energy that doesn’t come from old dinosaurs. Emissions have “runway”: how long we can keep pumping emissions into the atmosphere before making areas unlivable. We should calculate the runways, and make sure to finance programs with estimated time of finish before the end of the runway, while understanding that nothing is sustainable, and we need to evolve or die.
In these terms, the “sustainability” advocates say we must reduce the burn-rate to extend the runway. That’s one good idea of course, but it’s irrelevant before we made sure we understand how to get off the runway into the next process, and how long it is going to take. Even the most wild-flying start-up has some kind of plan, and so should we!