Life Cycle Assessment (LCA) - Overview, methodology, applications and limitations

There are various environmental assessment methods (impact assessment [0 024] , environmental management system [G 4 600] , carbon footprint [G 8 300] ...) and the choice of method depends on a number of criteria, including the purpose and objective of the study, the nature of the anthroposystems and ecosystems to be analyzed, and the type of environmental impact to be assessed. These methods are complementary, and none outclasses the others from a methodological or scientific point of view. In some cases, there is nothing to prevent the use of the same tools for calculating environmental impacts in the various environmental assessment methods, bearing in mind that there is no universal tool for calculating every environmental impact except for climate change. For this latter impact, we use the GWP (Global Warming Potential) or PRG (Potentiel de Réchauffement Global) indicator, which expresses, for a gas contributing to the increase in the greenhouse effect, the flux of infrared radiation it is capable of absorbing (radiative forcing) compared to CO ₂ .

One of the latest environmental assessment methods to be proposed is Life Cycle Assessment (LCA). Today, this method is covered by two standards: ISO 14040:2006, specifying the principles and framework for carrying out LCAs, revised by an amendment in 2020, and ISO 14044:2006, specifying the requirements and guidelines for carrying out LCAs, revised by two amendments in 2018 and 2020.

LCA makes it possible to assess the potential environmental impacts of an anthroposystem (a product, process or service) over its entire life cycle. Two specific features distinguish LCA from other environmental assessment methods: the notion of "life cycle" and the quantification of environmental impacts.

According to ISO, the life cycle is the set of "consecutive and linked phases of an anthroposystem, from the acquisition of raw materials or the generation of natural resources to final disposal". This concept allows us to take into account all the...