Using causal maps to identify potential sources of environmental impact outside the scope of LCA studies: preliminary findings from case studies on washing machines and road vehicles

Much of the environmental impacts of which a product will potentially have during its life cycle are determined during the design phase by choices such as type of materials and manufacturing processes. The Life Cycle Assessment (LCA) method is commonly used to assess the potential environmental impacts and identify hot-spots for improvements of a product system. However, other important variables exist outside the product system that can also influence environmental impacts. The aim of this study is to utilise causal maps to identify variables which may not typically be identified and considered in LCA studies but may have significant influence upon environmental impacts through cause-effect chains. To illustrate the utility of causal maps, household washing machines and conventional passenger cars are chosen as case studies. Preliminary findings indicate that causal mapping can be used to identify which are the relevant variables and describe how they potentially interact in a system perspective. This knowledge might allow for more robust decision support.