Laboratory for Manufacturing and Sustainability

Existing Life Cycle Assessment does not take into account the relative temporal differences in inventory data. The lack of such considerations could lead to an inaccurate analysis of impacts and to incorrect conclusions in the comparative studies of products with comparable inventories but different life cycle times. In this paper, we report on our research of the investigation of the embedded temporal differences in LCA, and propose a simple method to calculate the temporal space of the subject system for life cycle assessment. A case study is performed on VW Golf A4 Car based on previous LCA results. The temporal space of the vehicle, as estimated, is found to be approximately 11.04 years. We establish the emission pattern of CO2 along the time scale to demonstrate the effects of product life cycle durations on the LCA modeling and the inventory results. The life cycle inventory flow is discounted using a traditional economic discounting method with two discounting rates, 5% and 10%, respectively. The discounted results indicate that significant differences could be achieved on the life cycle inventory results.