Energy, complexity, and sustainability: A historical perspective

The common viewof history assumes that complexity and resource consumption have emerged through innovation facilitated by surplus energy. This view leads to the supposition that complexity and consumption are voluntary, and that we can therefore achieve a sustainable future through conservation. Such an assumption is substantially incorrect. History suggests that complexity most commonly increases to solve problems, and compels increase in resource use. This process is illustrated by the history of the Roman Empire and its collapse. Problems are inevitable, requiring increasing complexity, and conservation is therefore insufficient to produce sustainability. Future sustainability will require continued high levels of energy consumption to address converging problems. © 2010 Elsevier B.V. All rights reserved. 1. Resources and complexity Few questions of history and philosophy have beenmore enduring than how today’s complex societies evolved fromthe foragingbandsof our ancestors.While thishasbeenmainlyof academic interest, it has important implications for anticipating our future. Our understanding of sustainability depends to a significant degree on our understanding of the human past. My purposes are to show that conventional understandings of cultural evolution are untenable, as are assumptions about sustainability that follow from them, and to present a different approach to assessing our future. The focus of this essay is on cultural complexity, that is, complexity in such areas as society, politics, economics, technology, and information. While there are many concepts of complexity in various sciences, the term is used here to mean (a) differentiation in structure (i.e., more parts to a system, E-mail address: [email protected] 2210-4224/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.eist.2010.12.001 Author's personal copy 90 J.A. Tainter / Environmental Innovation and Societal Transitions 1 (2011) 89–95 and more types of parts); and (b) variation in organization, defined as constraints on potential ranges of behavior (Tainter, 1988). In human societies, differentiation in structure occurs in such areas as institutions, roles, technologies, and activities. Organization consists of constraints on behavior arising from such things as social norms, peer expectations, and hierarchical direction. Cultural complexity is commonly known by the term “civilization,” which we believe our ancestors achieved through “progress.” This “progressivist” view supposes that cultural complexity is intentional, that it emerged through the inventiveness of our ancestors. But inventiveness requires facilitating circumstances. What were those circumstances? Prehistorians once thought that the discovery of agriculture gave our ancestors surplus food and, concomitantly, free time to invent urbanism and the things that comprise “civilization” – cities, artisans, priesthoods, kings, aristocracies, and all of the other features of early states (Childe, 1944). The progressivist view thus posits a specific relationship between resources and complexity. It is that complexity develops because it can, and that the factor facilitating this is surplus energy. (“Surplus” in subsistence societies would usually mean food and other resources beyond annual household requirements. In more complex societies, surplus, as used here, includes both household production beyond subsistence needs and resources beyond those required for the ordinary activities of hierarchical control systems – such functions as maintaining order, creating public works, defending territory, and so forth.) In the progressivist view, energy precedes complexity and allows it to emerge. There are, however, significant reasons to doubt whether surplus energy has actually driven much of cultural evolution. One strand of thought that challenges progressivism emerged in the 18th and 19th centuries in the works of Wallace (1761), Malthus (1798), and Jevons (1866). Boulding derived from Malthus’s essay on population three theorems: the Dismal Theorem, the Utterly Dismal Theorem, and the moderately cheerful formof theDismal Theorem. TheUtterlyDismal Theoremdirectly challenges theprogressivist view: Any technical improvement can only relieve misery for a while, for as long as misery is the only check on population, the improvement will enable population to grow, and will soon enable more people to live in misery than before. The final result of improvements, therefore, is to increase the equilibrium population, which is to increase the sum total of human misery [Boulding, 1959: vii (emphases in original)]. The implication of this strain of thought is that humans have rarely had surplus energy. Surpluses, from whatever source, are quickly dissipated by growth in consumption. For example, Fig. 1 shows that as vehicles with higher fuel economy entered the U.S. fleet from the late 1970s on, Americans responded by driving more miles per year (http://www.eia.doe.gov/aer/txt/ptb0208.html), just as Jevons and Boulding would have predicted. This is known as the Rebound Effect, and it has been amply documented (Polimeni et al., 2008). If humans have rarely had surpluses, the availability of extra energy cannot be the primary driver of cultural evolution. Beyond a Malthusian view and the Rebound Effect, there is another factor that undermines progressivism. It is that complexity has costs. In non-human species this is a straightforward matter of additional calories. Among humans the cost is calculated in such currencies as resources, effort, time, or money, or by more subtle matters such as annoyance. While humans find complexity appealing in certain spheres, we are averse to complexity when it increases the cost of daily life without a clear benefit. Before the development of fossil fuels, increasing the complexity and costliness of a society meant that people worked harder. The development of complexity is thus a paradox of human history. Over the past 12,000 years, we have developed technologies, economies, and social institutions that cost more labor, time, money, energy, and annoyance, and that go against our aversion to such costs.Why, then, did human societies ever become more complex? At least part of the answer is that complexity is a basic problem-solving tool. (“Problem” is here defined as any threat to desired continuity, that is, to sustainability.) Confronted with problems, we often respond by developing more complex technologies, establishing new institutions, adding more specialists or bureaucratic levels to an institution, increasing organization or regulation, or gathering and processing more information. All of these have been done, for example, in responding to the Author's personal copy J.A. Tainter / Environmental Innovation and Societal Transitions 1 (2011) 89–95 91 Fig. 1. The Rebound Effect: fuel economy and annual miles driven, U.S., 1950–2007. Source: (http://www.eia.doe.gov/aer/txt/ptb0208.html). problem of terrorism.While we usually prefer not to bear the cost of complexity, our problem-solving efforts are powerful complexity generators. All that is needed for growth of complexity is a problem that requires it. Since problems continually arise, there is persistent pressure for complexity to increase. Cultural complexity can thus be viewed as an economic function. Societies invest in problem solving, undertaking costs and expecting benefits in return. In problem-solving systems, inexpensive solutions are adopted before more complex and expensive ones. In the history of human foodgathering and production, for example, hunting and gathering gave way to subsistence agriculture, which is ordinarily more labor-intensive (Sahlins, 1972; Cohen, 1977), and which in some places has been replaced by industrial agriculture that consumesmore energy than it produces.Weproduceminerals and energy whenever possible from the most economical sources. Our societies have changed from egalitarian relations, economic reciprocity, ad hoc leadership, and generalized roles to social and economic differentiation, specialization, inequality, and full-time leadership. These characteristics are the essence of complexity, and they increase the costliness of any society (Tainter, 1988). In the progressivist view, surplus energy precedes and facilitates the evolution of complexity. Certainly this is sometimes true: There have beenoccasionswhenhumans adopted energy sources of such great potential that, with further development and positive feedback, there followed great expansions in the numbers of humans and thewealth and complexity of societies. These occasions have, however, been so rare that we designate themwith terms signifying a new era: the Agricultural Revolution and the Industrial Revolution. One reason why humans do not ordinarily produce surpluses is declining productivity of labor. In subsistence economies, producing beyond what is needed for annual requirements generates diminishing returns to labor inputs (Sahlins, 1972; Boserup, 1965; Clark and Haswell, 1966). Both hunter–gatherers (such as theKalahari San) and subsistence agriculturalists (e.g., inVolokolamsk, Russia), who have comprised the bulk of human history, prefer leisure to the time and effort required to produce a surplus (Sahlins, 1972; Lee, 1968; Chayanov, 1966). Even in today’s economy, people report that they would prefer extra sleep to additional income (Benjamin et al., 2010). Surplus production has not been common in human history, nor has complexity. When human societies do have surplus energy, as industrial societies have over the past two centuries, it interacts with problem-solving to generate still more complexity. I term this the Author's personal copy 92 J.A. Tainter / Environmental Innovation and Societal Transitions 1 (2011) 89–95 Fig. 2. The energy-complexity spiral. energy-complexity spiral (Fig. 2). Abundant, inexpensive energy generates increasing complexity, and simultaneously produces new kinds of problems such as waste and climate change. Addressing these and other problems requires complexity to grow, imposing a need for still more energy. The times when humans have had surplus energy have, though, been rare and short-lived. The fact that we are in such a period today biases us to think that surplus energy is normal. Most of the time, cultural complexity increases from day-to-day efforts to solve problems. Complexity that emerges in this way will usually appear before there is additional energy to support it. Rather than following the availability of energy, cultural complexity oftenprecedes it. Complexity then compels increases in resource production. This understanding of the temporal relationship between complexity and resources has implications for sustainability that diverge from what is commonly assumed. Thesewill be explored shortly. It is useful first to present a historical case study, theWestern Roman Empire, that illustrates these points. 2. Case study: the Roman Empire The Roman Empire collapsed in the mid 5th century A.D., but its last 200 years of existence had been a reprieve. It had nearly been destroyed in the 3rd century. In the half-century from 235 to 284 the empirewas repeatedly breached by invasions of Germanic peoples from the north and the Persians from the east. When these invaders were not being repelled, Roman armies were fighting with each other in the service of would-be emperors. Many cities were sacked and productive lands devastated. Rival empires broke away in the east and thewest. It seemed that the RomanEmpirewould not survive much longer. The Roman government had a clear sustainability goal: the survival of the empire and of GraecoRoman civilization. In response to the crises, the emperors Diocletian and Constantine, in the late third Author's personal copy J.A. Tainter / Environmental Innovation and Societal Transitions 1 (2011) 89–95 93 and early fourth centuries, designed a government that was larger, more complex, and more highly organized. They doubled the size of the army. This was very costly. To pay for this sustainability effort, the government taxed its citizensmoreheavily, conscripted their labor, anddictated their occupations. With the rise in taxes, population could not recover from plagues in the second and third centuries. There were chronic shortages of labor. Marginal lands went out of cultivation. Faced with taxes, peasants would abandon their lands and flee to the protection of a wealthy landowner. The Roman Empire survived the 3rd century crisis and achieved two centuries of sustainability, but at the long-term cost of consuming its capital resources: agricultural lands and peasant population. When crises emerged again in the late 4th century, the empire had depleted its capacity to respond adequately and in time collapsed (Tainter, 1988, 1994; Allen et al., 2003). 3. Implications for sustainability transitions The Roman Empire is a single case study in complexity and problem solving, but it is an important and representative one. It illustrates the basic process by which societies increase in complexity. Societies adopt increasing complexity to solve problems, becoming at the same time more costly. In the normal course of economic evolution, this process at some pointwill produce diminishing returns. Once diminishing returns set in, a problem-solving societymust either find new resources to continue the activity, or fund the activity by reducing the share of resources available to other economic sectors. The latter is likely to produce economic contraction, popular discontent, and eventual collapse. This understandingof complexity and resourceshas implications for comprehending sustainability. (“Sustainability” is here defined by reference to the root word “sustain,” whichmeans to continue in a desired state or condition (OUP, 2007).) Both popular and academic discourse commonly assume that (a) future sustainability requires that industrial societies consumea lower quantity of resources than is now the case, and (b) sustainabilitywill result automatically if we do so. Sustainability emerges, in this view, as a passive consequence of consuming less. Thus sustainability efforts are commonly focused on reducing consumption through voluntary or enforced conservation, perhaps involving simplification, and/or through improvements in technical efficiencies. The common perspective on sustainability follows logically from the progressivist view that resources precede and facilitate innovations that increase complexity. Complexity, in this view, is voluntary. Human societies become more complex by choice. By this reasoning, we should be able to forego complexity and the resource consumption that it entails. Progressivism leads to the notion that societies can deliberately reduce their use of resources and thereby achieve sustainability. The fact that complexity and costliness increase through mundane problem solving suggests a different and startling conclusion:Contrary towhat is typically advocatedas the route to sustainability, it is usually not possible for a society to reduce its consumption of resources voluntarily over the long term. To the contrary, as problems great and small inevitably arise, addressing these problems requires complexity and resource consumption to increase (Tainter, 1988; Allen et al., 2003). As illustrated by the Roman Empire and more recent cases (Allen et al., 2003), this has commonly been the case.