"One doesn’t even need a model to put the main pieces together: [the] human population has been significantly inflated by [the] extensive exploitation of a non-renewable finite resource. Because the declining availability/use of that resource is inevitable (and likely near-at-hand), it stands to reason that present levels of population will be unsustainable—and that the necessary transition down from an overstuffed population will be very difficult to bear. The world left in the wake of our binge will be less able to support us than the one we inherited, exacerbating the hardship."