The concept of Urban Metabolism goes back to
Abel Wolman (see 1965), who was the first to draw the comparison between an
organism and a city. Cities, like organisms, need energy and resources such as
fuel, water or food as inputs to sustain life. These ‘metabolic inputs’ are
processed and ultimately released back to the environment as wastes. Hence, the
basic rationale behind the urban metabolism concept is that the relationship
between the environment and an urban system can be described by systematically recording
all flows to and from the environment in physical terms in analogy to
economy-wide material flow accounting (Eurostat 2001) or similar approaches. In
the absence of further information about environmental sources and sinks, this
is then usually regarded as an estimate of the pressure environmental pressures
generated by urban systems.
