Lecture
This lecture covers the optional elements in life cycle assessment (LCA) and the concept of normalization to evaluate the impacts of different scenarios in relation to a reference system. It explains how to compare the impacts of a scenario to those of a reference system by dividing the impact score of the scenario by the reference score in each impact category. The lecture also discusses the choice of normalization reference values, both external and internal, and provides examples of normalization factors. Additionally, it presents the calculation of normalized impact scores using examples and references from the field of LCA.