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World History and Energy World History and Energy VACLAV SMIL University of Manitoba Winnipeg, Manitoba, Canada history. But no energetic perspective can explain why 1. A Deterministic View of History complex entities such as cultures and civilizations 2. The Earliest Energy Eras arise and no thermodynamic interpretation can 3. Medieval and Early Modern Advances reveal the reasons for either their remarkable history 4. Transitions to Modernity or their astounding diversity of beliefs, habits, and 5. High-Energy Civilization and Its Attributes attitudes from which their actions spring. This article examines both of these contrasting views of energy 6. Limits of Energetic Determinism and world history. Glossary antiquity The era of ancient (from the Western perspective, 1. A DETERMINISTIC VIEW mostly the Middle Eastern and Mediterranean) civiliza- OF HISTORY tions extant between prehistory and the Middle Ages. determinism A doctrine claiming that human actions are Countless energy imperatives––ranging from the determined by external factors; its prominent varieties solar flux reaching the earth to minimum tempera- include environmental and geographic determinism. tures required for the functioning of thousands of early modern world The period immediately following the enzymes––have always shaped life on Earth by Middle Ages, variously dated as 1493–1800, 1550– 1850, or the 16th to 18th centuries. controlling the environment and by setting the limits energy transition A period of passing from one configura- on the performance of organisms. Deterministic tion of prime movers and dominant fuels to a new interpretations of energy’s role in world history setup. seems to be a natural proposition, with history seen middle ages The period between antiquity and the modern as a quest for increased complexity made possible by era, often circumscribed by the years 500–1500 CE. mastering higher energy flows. Periodization of this prehistory The period of human evolution predating quest on the basis of prevailing prime movers and recorded history. dominant sources of heat is another obvious propo- sition. This approach divides the evolution of the human species into distinct energy eras and brings A strict thermodynamic perspective must see en- out the importance of energy transitions that usher in ergy––its overall use, quality, intensity, and conver- more powerful, and more flexible, prime movers and sion efficiency––as the key factor in the history of the more efficient ways of energy conversion. Perhaps human species. Energy flows and conversions sustain the most intriguing conclusion arising from this and delimit the lives of all organisms and hence also grand view of history is the shrinking duration of of superorganisms such as societies and civilizations. successive energy eras and the accelerating pace of No action––be it a better crop harvest that ends a grand energy transitions. famine or the defeat of an aggressive neighbor––can The first energy era started more than 300,000 take place without harnessing and transforming years ago when the human species, Homo sapiens, energies through management, innovation, or daring. became differentiated from Homo erectus, and the Inevitably, the availability and quality of particular era continued until the beginning of settled societies prime movers and sources of heat and the modes of some 10,000 years ago. Throughout prehistory, all their conversions must have left deep imprints on efforts to control greater energy flows were capped Encyclopedia of Energy, Volume 6. r 2004 Elsevier Inc. All rights reserved. 549 550 World History and Energy by the limited power of human metabolism and by accomplishments that were achieved through inge- the inefficient use of fire. Domestication of draft nuity and better organization are noted. animals and harnessing of fire for producing metals and other durable materials constituted the first great energy transition: reliance on these extrasomatic 2. THE EARLIEST ENERGY ERAS energies had raised energy throughput of preindus- trial societies by more than an order of magnitude. During the long span of prehistory, the human The second transition got under way only several species relied only on its somatic energy, using millennia later; it was not as universal as the first one muscles to secure a basic food supply and then to and its effects made a profound, and relatively early, improve shelters and acquire meager material pos- difference only in some places: it came as some sessions. Organismic imperatives (above all, the traditional societies substituted large shares of their basal metabolism scaling as the body mass raised to muscular exertions by waterwheels and windmills, 0.75 power) and the mechanical efficiency of muscles simple but ingenious inanimate prime movers that (able to convert no more than 20–25% of ingested were designed to convert the two common renewable food to kinetic energy) governed these exertions: energy flows with increasing power and efficiency. healthy adults of smaller statures cannot sustain The third great energy transition––substitution of useful work at rates of more than 50–90 W and can animate prime movers by engines and of biomass develop power of 102 W only during brief spells of energies by fossil fuels––began only several centuries concentrated exertion. The former performance ago in a few European countries and it was sufficed for all but a few extreme forms of food accomplished by all industrialized nations during gathering and the latter exertions were called on for the 20th century. That transition is yet to run its some forms of hunting. Simple tools made some course in most low-income economies, particularly foraging and processing tasks more efficient and in Africa. The latest energy transition has been under extended the reach of human muscles. way since 1882 when the world’s first electricity- Energy returns in foraging (energy in food/energy generating stations were commissioned in London spent in collecting and hunting) ranged from barely and New York (both Edison’s coal-fired plants) and positive (particularly for some types of hunting) to in Appleton, Wisconsin (the first hydroelectric seasonally fairly high (up to 40-fold for digging up station). Since that time, all modernizing economies tubers). The choice of the collected plants was have been consuming increasing shares of their fossil determined above all by their accessibility, nutri- fuels indirectly as electricity and introducing new tional density, and palatability, with grasslands modes of primary electricity generation––nuclear offering generally a better selection of such species fission starting in the mid-1950s, and later also wind than did dense forests. Collective hunting of large turbines and photovoltaic cells––to boost the overall mammals brought the highest net energy returns output of this most flexible and most convenient (because of their high fat content) and it also form of energy. The second key attribute of this contributed to the emergence of social complexity. transition has been a steady relative retreat of coal Only a few coastal societies collecting and hunting mirrored by the rise of hydrocarbons, first crude oil marine species had sufficiently high and secure and later natural gas. energy returns (due to seasonal migrations of fish Improving the quality of life has been the principal or whales) such that they were able to live in individual benefit of this quest for higher energy use permanent settlements and devote surplus energy to that has brought increased food harvests, greater elaborate rituals and impressive artistic creations (for accumulation of personal possessions, abundance of example, the tall ornate wooden totems of the Indian educational and leisure opportunities, and vastly tribes of the Pacific Northwest). enhanced personal mobility. The growth of the The only extrasomatic energy conversion mas- world’s population, the rising economic might of tered by prehistoric societies was the use of fire for nations, the extension of empires and military warmth and cooking, which can be indisputably capabilities, the expansion of world trade, and the dated to approximately 250,000 years ago. Eventual globalization of human affairs have been the key shifts from foraging to shifting cultivation and then collective consequences of the quest. These advances to sedentary farming were gradual processes driven are discussed in this article and the limits of prime by a number of energy-related, nutritional, and social movers and heat sources that were available during factors: there was no short and sharp agricultural the successive eras of energy use and the major revolution. These changes were accompanied by World History and Energy 551 declining net energy returns in food production, but harvests were barely adequate to provide subsistence these declines had a rewarding corollary as the higher diets. Those agroecosystems where grazing land was investment of metabolic energy in clearing land and also limited (the rice regions of Asia) could support in planting, weeding, fertilizing, harvesting, and only relatively small numbers of draft animals. processing crops, as well as storing grains or tubers, Limited unit power of muscles could be overcome made it possible to support much higher population by massing people, or draft animals, and the densities. Whereas the most affluent coastal foraging combination of tools and organized deployment of societies had densities less than 1 person/km2 (and massed labor made it possible to build impressive most foraging societies had carrying capacities well structures solely with human labor. Massed forces of below 0.1 person/km2), shifting agricultures would 20–100 adults could deliver sustained power of 1.5– easily support 20–30 people/km2 and even the earliest 8 kW and could support brief exertions of up to extensive forms of settled farming (ancient Meso- 100 kW, enough to transport and erect (with the help potamia, Egypt and China’s Huanghe Valley) could of simple devices) megaliths and to build impressive feed 100–200 people/km2, that is, 1–2 people/ha of stone structures on all continents except Australia. In cultivated land (Fig.
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