"Not to say that one would have to go back to a hunter-gatherer [or even a herbivore-insectivore] mode of existence in order to live on a solar budget. Pick any preindustrial culture you like, or pick the best or most relevant parts from any of them to get on with daily life, for instance, the habitations of Edo Japan, the division of labor of the Inca, the diet of the Florentines, the animal husbandry of Georgian England, the costumes of the Ming dynasty. Surely one could contrive life on a solar budget from these modes of daily endeavor and put together a satisfying existence that would amount to being civilized. Anyway, a great many of the useful inventions that made life comfortable and interesting were developed before we began using fossil fuels, quite a few of them in China alone. Add to that some additional knowledge that the human race has acquired since those historical periods, perhaps only the germ theory of disease, and you could enjoy a decent living standard. Anyway, that’s a theory. History does run backward now and then, and the centers of civilization shift from one place to another, but we've never seen anything like what we face: the crash of a turbocharged cheap energy economy along with an ecological catastrophe perhaps beyond the biblical scale. History is also not symmetrical; you don’t necessarily go down the same way you came, recapitulating earlier arrangements in the same sequence backward. What we might get instead could be just a one-way ticket to Palookaville instead of getting to relive the sixteenth century."