The Energetic Metabolism of Societies, Part II: Empirical Examples
Part I of this set of articles proposed methods to account for the energetic metabolism of societies. In this second part, the methods explicated in Part I are used to analyze the energy flows of societies with different 'modes of subsistence': hunter-gatherers, a contemporary agricultural society in southeastern Asia, and a contemporary industrial society (Austria). The empirical examples are used to demonstrate differences in the 'characteristic metabolism' of different modes of subsistence. The energy system of hunter-gatherers can be described as an 'uncontrolled solar energy system,' based mainly upon harvesting biomass without attending to its reproduction. Hunter-gatherers use only about 0.001% to 0.01% of the net primary production (NPP) of the territory they inhabit. Agricultural societies harness NPP to a much higher extent: Although agriculture often reduces NPP, the amount of biomass that agricultural societies use is much higher (about 20% of potential NPP). Because ecological energy flows are the main source of energy for agricultural societies, NPP strictly limits the energetic metabolism of agricultural societies. Industrial society uses area-independent energy sources (fossil and nuclear energy), which, however, result in new sustainability problems, such as greenhouse gas emissions. By providing methods to account for changes in energy flows, the metabolism approach proves itself to be a useful concept for analyzing society-environment interactions. The article demonstrates the difference between the metabolism approach and conventional energy statistics and discusses the significance of the proposed approach for sustainable development.