Extract

Recent models of sustainable industrial system growth reflect an increased interest in changing material flows in urban and rural landscapes and populations. Within this context, the term ‘changing material flows’ means introducing new commodity uses and sources or ending existing ones and introducing new waste treatments into the environment or placing a moratorium on others. There are many examples that illustrate this trend, such as using field crops for biofuels production instead of food production and recycling waste materials to retain their value. A framework for modeling and assessing the impact of material flows to advance the mutual goals of sustainable industrial, urban, and rural systems is explored here through an urban setting case study. The environmental impact and economic benefits of these flows occur at different spatial levels and scales, from the individual urban scale to international trade and the global environment. This requires developing and using models that can capture, quantify, and qualify materials and flows across these different scales in order to comprehensively assess their impacts.