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What is an LCA?
12th February 2009
Life Cycle Assessment (LCA) analyzes the complete life span of a product, starting with the extraction of raw materials, and tracing all operations from manufacturing and transportation to product use and end-of-life processes like recycling, energy recovery, and waste disposal (cradle to grave).
History
LCA originated in the late 1960’s when engineers began looking at industrial systems (as opposed to individual unit operations) to improve their overall performance. In the early 1970’s, LCA’s concentrated mainly on energy and raw materials inputs in industrial systems. Later, air emissions, water emissions and solid waste outputs were included in the calculations with the aim of optimising the environmental characteristics of the system. Now common categories of assessed damage relating to both inputs and outputs include global warming (greenhouse gases), acidification, ozone layer depletion, eutrophication, eco-toxicological and human-toxicological pollutants, habitat destruction, desertification, land use as well as depletion of minerals and fossil fuels.
Methodology
The LCA methodology has been collaboratively defined by a number of institutions, most notably the University of Leiden’s Department of Industrial Ecology. The three main stages of LCA practice, ‘Inventory, Interpretation and Improvement,’ were first outlined at the 1990 Society of Environmental Toxicology and Chemistry (SETAC) conference in Vermont. Now ISO standards 14040:2006 and 14044:2006 and PAS 2050, in alignment with Planet Positive, provide robust requirements for performing transparent LCA calculations.
LCA practitioners begin by defining the goal of the study and the functional unit they are analyzing. They then delineate the product’s system boundary, which determines which unit processes are included in the LCA.
i. Inventory
The inventory stage of the LCA involves compiling data on all of the inputs and outputs that pass through the system boundary and modelling the product system. Practitioners source emissions factors from extensive databases containing life cycle profiles of many goods and services, as well as many of the underlying materials, energy resources, transport systems, etc. Usually Life Cycle Assessments inventories and modelling are carried out using dedicated software packages such as GaBi or SimaPro.
ii. Interpretation
In the interpretation stage, the physical data from the inventory are related to contributions to impact categories such as global warming. An analysis of major contributions, a sensitivity analysis and an uncertainty analysis are carried out in order to facilitate decision-making in the improvement stage, where modifications can be made to improve the efficiency of the system and reduce negative environmental impacts.
iii. Improvement
The Improvement stage is crucial if the LCA is to produce environmental benefits as it modifies the process to reduce the observed environmental impacts. Once these reductions have been suggested, the first two LCA stages are changed to consider the recommended actions.