The approach that would become LCA first emerged in the 1960s and 1970s, though there was little consistency in how such analysis was practiced. However, by the 1990s, the international scientific community made steps to standardize LCA. This led to a commitment by the International Organization for Standardization (ISO) in 1994 to create today’s LCA standards including guidelines and the principles and framework.
In 2002, the United Nations Environmental Programme (UNEP) and the Society for Environmental Toxicology and Chemistry (SETAC) moved to advance LCA through the creation of the Life Cycle Initiative. By 2005, the European Union, the United States Environmental Protection Agency, and many other government bodies had implemented policies promoting the use of LCA as part of sustainability initiatives.
Today, LCA is a methodology used by scientists, policymakers, and business leaders to set sustainability goals. It is often used in conjunction with other well-known tools, like material-flow analysis (MFA).
The ISO standards describe the principles and full framework for conducting an LCA. The assessment is broken down into the following four phases:
- goal and scope definition
- life cycle inventory analysis (LCI)
- life cycle impact assessment (LCIA)
Each step is described in greater detail below. Highlights from an actual LCA performed by the New York State Pollution Prevention Institute (NYSP2I) are also included in order to better illustrate each phase of the study.
Step 1: Goal and scope definition
Accounting for all the many potential impacts of an entire manufacturing process would require an incredible amount of time, data, knowledge, and resources—there are limits to the breadth and data quality of any analysis, after all. An LCA analyst makes this task manageable by first clearly defining an LCA’s goal and scope.
Functional units, system boundaries, and limits to the analysis are set to outline where in the life cycle the study begins and where it ends, and to identify what processes within the technical system will be assessed. A functional unit is the basis for the study. It is a measurement of production or output against which impact indicator metrics are normalized.
The scope of an LCA is determined by the number of life cycle stages and impact categories that will be assessed. One assessment might take in just one life cycle stage and one impact, making it very targeted and focused. Another might be far more comprehensive in scope, addressing an entire life cycle across many impact categories. Between these two poles stand many possibilities.
A business is more likely to prefer an LCA that is narrow in scope—it requires far less time and resources to perform, and it’s more likely to lead to actionable results. However, its limited range often means turning to supplemental data sources and estimated measurements to fill in gaps. A truly comprehensive study, as an attempt to model all of a manufacturer’s activities, would generate a complex set of data that would not lend itself as easily to practical interpretation. Yet this richer data is attractive to researchers and policymakers because it can help them understand real-world conditions more accurately.