This lecture focuses on the principles and methodologies of Life Cycle Assessment (LCA), a systematic approach to evaluating the environmental impacts of products and services throughout their life cycle. The instructor discusses the importance of defining the functional unit, which serves as a basis for comparison between different products. The lecture covers the various stages of LCA, including goal definition, inventory analysis, impact assessment, and interpretation. The instructor emphasizes the need for a comprehensive view of the product life cycle, from resource extraction to end-of-life disposal. The discussion includes the significance of multi-criteria evaluation, highlighting the various environmental impacts that must be considered, such as greenhouse gas emissions and resource consumption. The instructor also addresses the challenges of data availability and the importance of using standardized methods to ensure consistency in assessments. By the end of the lecture, students gain insights into how to apply LCA in real-world scenarios, enabling them to make informed decisions regarding product sustainability.