Insights

Materials societies accumulate in buildings, infrastructures, and products are a key element of social metabolism dubbed ‘material stocks’ in sociometabolic research. Globally, the fraction of all material extraction used to build new or replace / maintain existing material stocks has increased from just over 20% in 1900 to nearly 60% today. The remaining share consists of materials used for energy, food/ feed and other dissipative purposes. Most material stocks are in buildings and infrastructures, though vehicles and industrial machinery also play important roles.

Societies use physical resources (both stocks and flows of materials and energy) for production and consumption activities that provide essential services such as nutrition, shelter, mobility, education, healthcare, and others. Service provision almost always requires specific combinations of stocks and flows. For instance, providing living space requires material stocks in the form of a building, energy flows for heating, cooling or lighting, as well as material flows for maintenance.

The concept of a stock-flow-service nexus shifts attention toward the potential for delivering services with fewer and more environmentally sustainable resources. For example, well-designed buildings can offer comfortable living conditions while using minimal heating or cooling energy, whereas poorly designed ones may require 10-100 times more energy to deliver the same service.

The construction and maintenance of material stocks, as well as the biophysical flows required for their use, are usually supplied in complex, and often international supply chains. The resilience of supply networks hinges on the qualities and quantities of the materials as well as the structure of the supply chains themselves. Current sociometabolic methods are generally descriptive or static and thus ill-equipped to assess supply chain resilience. An important goal of REMASS is to develop methods and models that can account for disruptions and non-linear dynamics, including tipping points in socio-ecological systems.

Material stocks often require large investments and embody substantial value, making them important capital stocks. Their design often requires energy or material flows during use, thereby locking service provision into specific, and often unsustainable patterns of resource consumption. They are therefore central for understanding the malleability of social metabolism, i.e. the extent to which it can be shaped through purposive actions. Assessing these lock-ins and identifying options to transform existing stock patterns towards more sustainable configurations is thus a central objective of REMASS.