I’ve had this discussion with others recently.
There’s a lot of misunderstanding about “resource shortage”. Resources are always in a shortage situation. That’s why they’re considered “resources” and not (as a rule) “givens”, such as air and water. (And yes, air and especially “clean water” certainly are scarce resources in some parts of the world.)
But the thing is that in the relatively free markets in which most resources are traded, price is an indicator of scarcity. That needs to be repeated: price indicates scarcity. “Price” is vital information to consumers that they need to conserve the resource or look for alternative technology that doesn’t use so much of “that”, or can recover the resource after use, etc. It also sends a signal to producers that “it’s now more worth your time and effort to capture the dregs of the resource that you had given up on earlier.”
What that means is that as prices for non-renewable resources rise, then it becomes more economically viable to search for alternatives (such as alternative fuels and other energy supplies, for example) or alternative sources for the existing resources. So in that way “used-up” energy fields such as previously tapped-out oil fields, for example, are made economically viable again to exploit for “the final 10%” of the resource that was not going to be recovered under previous modes of drilling and pumping. It wasn’t worth the effort before; as prices rise, then it’s worth the effort, as long as there’s a return on the investment that it takes to recover it.
So the thing is, we don’t run along fat, dumb and happy… and all of a sudden run off a cliff as we use the last drop of oil, or the last hundred cubic feet of natural gas, coal or nearly anything else that can be privately owned and controlled. The signals of pending shortage are sent by and to producers (and received by consumers) for a long time before the thing runs out.
Resources held in “commons”, where no one has to pay for the development of a mine, for example, and can control access, can also be used up. That’s why overfishing of pelagic fishes is a real problem. We can fish some desirable species of fish to extinction, or to a point where the species is no longer economically viable. That could happen to bluefin tuna, for example, as it has happened to many other species. Since no one “owns” tuna, the cost to obtain one is just the cost of a boat and crew to go out on the ocean, hunt it down and capture it. Once it’s captured, then its value is… whatever one can get for it. That makes the last few tuna as precious as diamonds to whoever can capture it, and makes it more certain that it will be captured.
Supermarkets aren’t going to close, in other words. Electricity won’t run out; we’ll just produce it in new ways (some of which we already know, such as hydro, solar and wind, some which are currently under-utilized in most of the world, such as geothermal, and coal for perhaps another hundred years or so, though there will still be mountains full of the stuff, and gas because there’s a lot more of that available than you imagine – more than the current producers even imagine, in fact).