| dc.description.abstract | Growth in global population and living standards, along with the transition to a low-carbon economy, require increasing supply of an unprecedented variety of material commodities. Consequently, securing availability of “natural resources” is a key priority for sustainable development as it applies to policy and product design.
Life Cycle Assessment (LCA) – which has been applied in policy and product design for decades – has traditionally been a tool for measuring potential environmental impacts of products from “cradle” to “grave.” More recently, the term Life Cycle Sustainability Assessment (LCSA) has emerged to incorporate socio-economic considerations alongside environmental issues. While environmental LCA methodology is relatively well developed, socio-economic aspects of “natural resources” have long been controversial in the LCA community. Conventional approaches concern “inside-out” impacts of resource depletion and scarcity in the long-run. In contrast, newer approaches for resource “criticality” assessment – which have emerged outside the LCA community – concern “outside-in” mechanisms that can disrupt raw material availability in the short-run. Methods for criticality assessment, however, have had limited applicability on a product-level because they do not provide a clear connection to a functional unit of a given product – a central concept in LCA.
Therefore, this thesis aims to extend the previously developed Geopolitical Supply Risk (GPSR) method from a relative assessment of raw material criticality to a Life Cycle Impact Assessment characterization model for assessing supply risk in relation to a functional unit under the LCSA framework. The characterization model is based on a socio-economic cause-effect mechanism drawing upon supply chain resilience concepts. Supply risk for a given commodity is defined as the multiple of probability of supply disruption and vulnerability to supply disruption. The method is demonstrated through LCA case studies of electric vehicles and dental x-ray equipment.
While “minor” commodities are often neglected in environmental LCA, the case studies herein illustrate how small components can “pack a punch” from both a supply risk and environmental perspective. Therefore, the most promising embodiment of the GPSR characterization model “cancels out” the amounts of commodity inputs. As a consequence, comprehensive data are required for product material composition. The x-ray case study, for example, involves tracing unit processes through LCA databases so that commodity inputs can be matched with identification codes for collecting commodity trade data. On the other hand, it is convenient that the amounts of commodity inputs need not be known.
Although the GPSR characterization model shows promise as a product-level decision support tool, the method and applications presented in this thesis are limited to single-stage supply chain modelling. Moreover, while the method is presently at the country-level, product supply chains are actually at the firm-level. Recycling, co-production, and commodity stockpiling are other areas for further methodological development. Finally, greater computational power is needed to facilitate practical application of the GPSR method. Nonetheless, this thesis shows the importance of integrating raw material criticality and environmental considerations into LCSA to better inform design and management decisions on a product-level. | en |
