The Emphatic Civilization
Jeremy Rifkin
Rome
Plant cultivation—aided by irrigation systems—greatly increased the yield per unit of human energy or labor expended. Agricultural surpluses also freed at least some people from toil on the land. Freeing people from labor created the beginnings of a social hierarchy and the differentiation of tasks. Priest and warrior classes slowly emerged, as did an artisan class somewhat later on. The differentiation and specialization of tasks spawned new, more complex institutional arrangements ...
Later in history, our forebears captured and 'harnessed' one another as energy-producing power plants—a process that continued apace until the latter part of the 19th century—and used human slavery as a means to increase energy flow. Slave labor built the great pyramids of Egypt, the Great Wall of China, and the ceremonial shrines of the Mayan and Teotihuacan civilizations in the Americas. The Great Wall in China required the labor of more than a million slaves, half of whom perished in the effort.12 Nearly 20 percent of the population of Rome in the first few centuries A.D. were slaves. ...
Maintaining [Rome's] infrastructure and population in a non-equilibrium state [ruling over bunch ppl, centrally is inherently unstable] required large amounts of energy. Its energy regime, however, was becoming exhausted. With no other alternative sources of energy available, Rome put even more pressure on its dwindling energy legacy. By the fifth century, the size of the government and military bureaucracy had doubled. To pay for it, taxes were increased, further impoverishing the population, especially the dwindling farm population. The empire, writes Joseph Tainter, began consuming its own capital in the form of 'producing lands and peasant populations'.
Weakened by a depleted energy regime, the empire began to crumble. Basic services dwindled. The immense Roman infrastructure fell into disrepair. The military could no longer hold marauding invaders at bay. Barbarian hordes began to whittle away at the decaying Roman Empire, at first in distant lands. By the sixth century, the invaders were at the gates of Rome. The great Roman Empire had collapsed. By the sixth century, the population of Rome, once numbering more than 1,000,000, had shrunk to less than 30,000 inhabitants. The city itself was reduced nearly to rubble, a stark reminder of how unforgiving the energy laws are.
The [damage] was enormous. The available free [resources] of the Mediterranean, North Africa, and large parts of Continental Europe, reaching as far north as Spain and England, had been sucked into the Roman machine. Deforested land, eroded soil, and impoverished and diseased human populations lay scattered across the empire. Europe would not recover for another 600 years ...