ABSTRACT
In an analogy to the metabolism of a living organism, the concept of social metabolism proposes that a society requires material and energy inputs which it processes and assimilates for the purposes of societal reproduction and then discharges as wastes or emissions (Ayres and Simonis, 1994; Fischer-Kowalski, 1998; Martinez-Alier, 1987). The magnitude and composition of the biophysical flows and stocks, or the metabolic profile, which characterize a socio-economic system strongly depend on how the society in question is organized (Sieferle, 2003). Functional links between different types of material and energy strongly influence metabolic profiles. Societies of hunters and gatherers passively use solar energy by collecting wild-growing plants and hunting wild animals. This metabolic mode supports low population densities and a nomadic life which in turn prohibits the accumulation of material possessions. Biotic materials ‘fuel’ this form of societal organization and the use of other materials is only marginally possible and necessary. By actively harnessing solar energy and cultivating plants and domesticating animals, agrarian societies enable higher population density in a sedentary way of life with a significant impact on material use for buildings, tools, and other durable possessions. The dramatic shift in society’s resource basis is accompanied by comparable shifts in organization, including the ability of agrarian societies to support labor that is not directly required for food provisioning as well as higher fertility rates. The agricultural surplus which can be produced also allows for some degree of urbanization. The use of fossil energy in industrial societies is linked to a completely new form of social organization in which the majority of the population must no longer work in the provisioning of food. Fossil energy both requires and enables the use of materials (such as metals, for example) which were only marginally used in agrarian societies. With high shares of construction minerals, fossil energy carriers, and metals, the metabolic profile of industrial societies is not only characterized by much higher per capita values for material use but also by a composition completely distinct from that of hunters and gatherers or agrarian societies in which biomass was dominant. It has been suggested that the increase of per capita energy availability in industrial societies may be linked to the occurrence of social revolutions (Fischer-Kowalski et al., 2014), possibly related to the degree to which the use of fossil energy allowed human societies to defy what was previously seen as the ‘natural order’ of things and therefore 80unchangeable: to light up the dark, to develop machines with superhuman strength and endurance, to alter the temperature of the environment (Lord, 2014).
