Edited by Matthias Ruth and Brynhildur Davidsdottir
Chapter 4: Dynamic Modeling of Material Stocks: A Case Study of In-Use Cement Stocks in the United States
Amit Kapur and Gregory A. Keoleian INTRODUCTION Rapid industrialization and the rise of consumerism have transformed the global landscape. Since the middle of the last century in North America, Western Europe, Japan, and a few other countries, the culture of “overconsumption” has grown exponentially, bringing with it an unprecedented appetite for physical goods and the materials from which they are made (Young and Sachs 1994). In highly populated countries such as China, the levels of consumption of basic commodities such as grain, meat, coal, and steel have surpassed the previous highest consumer, the United States (Brown 2005). Material-based economies today face the challenge of how to make our needs and use of materials sustainable. The assessment of sustainability with regard to resource use and management can be broken down into three components: (1) relationship between rate of resource use and overall stock of resources, (2) eﬀectiveness of resources in providing essential services, and (3) the proportion of resources that are lost from the economy and their impacts on the environment. The ﬁrst two topics reﬂect the sustainability of supply, and the third aﬀects the sustainability and health of receiving ecosystems where exiting, no longer in use, resources from the economic system accumulate and reside. The approach to establish and quantify the relationship between societal resource management and sustainability is an emerging subject of research in the ﬁeld of industrial ecology (Graedel and Klee 2002). The concept of “industrial metabolism” (ﬁrst introduced by Robert Ayres in Ayres 1989a;...