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Introduction to LCA

Overview

Life cycle assessment , LCA, is a methodological tool that applies life cycle thinking in an quantitative way on environmental analysis of activities related to processes or products (goods and services). A central characteristic of life cycle assessment is the holistic focus on products or processes and their functions, considering upstream and downstream activities.

The life cycle concept: An LCA of a product includes all the production processes and services associated with the product through its life cycle , from the extraction of raw materials through production of the materials which are used in the manufacture of the product, over the use of the product, to its recycling and/or ultimate disposal of some of its constituents. Such a complete life cycle is also often named "cradle to grave ". Transportation, storage, retail, and other activities between the life cycle stages are included where relevant. This life cycle of a product is hence identical to the complete supply-chain of the product plus its use and end-of-life treatment.

Figure: llustration of a product life cycle - plastic part in a car.

In an LCA, for each single process step, the use of resources, raw materials, parts and products, energy carriers, electricity, etc. are documented as "Inputs". Emissions to air, water and land as well as waste and by-products are recorded on the output side ("Outputs") (see next figure).
For products as Inputs coming from the technosphere their "environmental history" has to also be included in the calculations by including their indirect upstream activities. For wastes, the subsequent treatment processes have to be included accordingly. The total sum of inputs from, and outputs to, the nature is the basis for a later analysis and potential assessment of the environmental effects related to the product or process. This aggregation of the many single resources and emissions to environmental and health impacts is called Life Cycle Impact Assessment; also illustrated in the next figure.

Figure: Scheme of a product system's life cycle with data collection of product and waste flows (blue lines) and resources (green) and emissions (grey arrows) followed by the impact assessment of the emissions and resource consumption.

Why a life cycle perspective? - The "shifting of burdens" issue: Including the whole life cycle helps ensure that no environmental burdens are shifted to other life phases, i.e. it is avoided that improvements in one part of the life cycle (e.g. production) lead to even higher impacts in other parts of the same life cycle (e.g. the product use), and vice versa. At the same time, an LCA helps to identify and avoid the shifting of burdens among different impacts, as it can and should consider in parallel effects on e.g. Climate Change, Acidification, Summer Smog, Natural Resource Consumption etc.

Applications of LCA: LCA has found widespread applications in product development in industry, marketing of products, and within policy making to name a few. It is a cornerstone of the European Integrated Product Policy , IPP (COM (2003) 302) and the new Thematic Strategies on Waste Prevention and Recycling (COM (2005) 666) and on the Sustainable Use of Natural Resources (COM (2005) 670). These aim to reduce environmental impacts throughout the life cycle of products, with a specific focus on the impacts in general, those related to waste, and those related to resource consumption, respectively.

International standardisation: A framework for LCA has been standardised by the International Organisation for Standardisation (ISO) in the ISO 14040 series. It consists of the following elements:

  • Goal and scope definition defines the goal and intended use of the LCA, and scopes the assessment concerning system boundaries, function and flow, required data quality, technology and assessment parameters.
  • Life Cycle Inventory analysis, LCI , is an activity for collecting data on inputs (resources and intermediate products) and outputs (emissions, wastes) for all the processes in the product system.
  • Life Cycle Impact Assessment, LCIA , is the phase of the LCA where inventory data on inputs and outputs are translated into indicators about the product system’s potential impacts on the environment, on human health, and on the availability of natural resources.
  • Interpretation is the phase where the results of the LCI and LCIA are interpreted according to the goal of the study and where sensitivity and uncertainty analysis are performed to qualify the results and the conclusions.

Further introduction into the details of the standard and the procedure of performing a full LCA you may find in the other chapters of these introduction texts.


Last update: 1 October 2008 | Top

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