Most of the existing life cycle sustainability assessment (LCSA) frameworks do not adequately consider the role of stakeholders in the assessment process, rebound effects, how the concept of vulnerability and resilience are... [ view full abstract ]
Most of the existing life cycle sustainability assessment (LCSA) frameworks do not adequately consider the role of stakeholders in the assessment process, rebound effects, how the concept of vulnerability and resilience are related to a product’s life cycle, and how stakeholders’ risk aversion can be applied to life cycle thinking; yet, these factors will impact the sustainability of the product’s life cycle. The framework of life cycle sustainability unified analysis (LiCSUA) was created with the key objective to address these four outstanding issues. Additionally, it aims to establish the presence of cross-linking indicators and inter/intra-dimensional consequences, and define vulnerability of a life cycle system with respect to the changes made certain sustainability indicators of that system. The main methodology involves creating a mathematical model that links the vulnerability of life cycle system to the rate of change to a certain sustainability indicator caused by an external “shock” applied to the system. Rebound effects were derived using a control theoretic approach, whereas stage-wise resilience, interlinkages and adaptive capacity were all defined based on empirical data; most of these relationships are linear in nature and they are supported by data obtained from construction and waste recycling industries around the world. For example, between 2005 and 2014, the total packaging waste (including wood packaging) recycling rate of European Union was found to exhibit a linear trend. The model was applied to evaluate the impact of flash floods on the wood-plastic composite (WPC) industry, measured in terms of the time rate of change of wood waste recycling behavior of residents. The life cycle stages considered were: use phase of timber in buildings, sorting/salvaging of wood waste, re-processing of the salvaged wood into WPC, utilization of WPC for construction, and the use phase of the WPC. Several scenarios in which different “strengths” of the various aforementioned factors were examined. In one scenario, it was found that although the floods’ net impact on the WPC life cycle system diminishes with time, there may be “aftershocks” that occur after the 1st, 10th and 15th years, due to the interactions among the various life cycle stages of WPC that takes time to manifest. Such a phenomenon has never been explicitly discussed in the literature. This shows that policies that aim to reduce the net impact on the WPC industry should be sustained over at least 15 years. In the second scenario – in which the resilience of the life cycle stages was increased by more than three times (for example, by drastically increasing the water resistance of WPC products) – it was found that there will no longer be any “aftershock” after the 1st year, so the overall impact on the WPC system is reduced. Two other scenarios were also evaluated. In conclusion, these results provide useful perspectives on how policies can affect a life cycle system’s ability to assimilate impacts as a result of the interplay among the aforementioned factors.
Key words: life cycle sustainability, wood plastic composites, resilience, vulnerability, rebound effects
1c. Assessing sustainability (indicators and reporting)
