Humans consume and distribute resources on a scale unparalleled in non-human systems. Infrastructure networks such as electric-power grids, oil pipelines, railroads, airports, trade routes, banking systems, and communication systems make this global scale consumption and distribution possible. This talk examines the scale of these networks and the scaling relationships in human societies that result from them. The Metabolic Theory of Ecology (MTE), originally intended to explain how flows through the cardiovascular network determine life history characteristics of organisms, offers a way to understand the dynamics of flow through infrastructure networks and how those flows determine properties of societies. Because cities dominate energy and material flows in contemporary societies, the talk will focus on urban infrastructure networks.
The scale of energy distribution networks affects reproduction, demography, and economics. The relationships suggest that many infrastructure networks are characterized by diminishing returns—larger networks deliver energy less efficiently than smaller networks. Understanding the structure and dynamics of infrastructure networks, is crucial to understanding sustainability and other broad scale properties of modern societies.