Scientists follow products from the cradle to the grave to make an inventory of all impacts
To compare the environmental impacts of product alternatives, it is necessary to study the entire life cycle of the product: from mineral extraction, through manufacture, use and disposal.
This technique is known as Life Cycle Assessment (LCA). It is a recommended technique of the European Commission, and therefore is present in EU policies regarding environmental impact assessment. Examples are Ecolabel Regulation, Green Product Procurement, Ecodesign Directive, Resource Efficiency initiatives, and as the reference methodology for product and organisation assessment.
The LCA can help in improving the environmental performance of a product or system by:
An LCA is an analysis of the entire life cycle of a product, from raw material extraction through manufacture, transport and use, to disposal.
The procedure of Life Cycle Assessment of products is defined by ISO Standard 14040. This standard specifies 4 phases:
An LCA study must state clearly what the overall purpose is, what decisions may be made on its findings, and whether the results are for public or internal consumption.
Scoping identifies the function, system, system boundaries, functional unit, data requirements, alternatives for products or services, key assumptions, anticipated limitations, geographical and time limits.
A functional unit is defined, so that unlike products and services may be compared across the board.
The system boundaries are defined in a fair way, so that the project does not grow beyond the resources provided. It may be acceptable to create groups of types of supply industries and disposal mechanisms.
Which environmental impacts exist in the production, use and disposal of the product? The inventory makes quantitative statements concerning the major stages of the entire life cycle path, concerning the consumption of raw materials and energy, and emissions of pollution. There are a large number of software systems and databanks to aid in this task.
The Inventory involves the collection of data about all inputs and outputs of a system, and requires decisions concerning allocation. In the inventory procedure, there are are a number of software processes, which contain algorithms for the calculation of cumulated inventory results, as well as reference databanks.
In order to answer the question of how great the impact on the environment resulting from this product or service is, the impact assessment of the results of the inventory are grouped by scientific criteria into different impact categories.
The major impact categories are: global warming, ozone depletion, acidification, eutrophication, photochemical ozone creation, abiotic depletion potential (Abiotic Depletion Factor, ADF) for non-fossil and fossil resources.
The modelling can be based on a selection of so-called mid-points (impact categories), or end-points, such as human health, protection of natural resources, and ecosystem quality. These end-points can be weighted to provide a means of aggregating the impacts of different types.
The ecological scarcity method is used in this capacity for a "difference to tolerance" calculation.
Now that the goals have been defined, an inventory of material and energy flows, and their impacts, calculated and allocated to environmental impact categories, an assessment is possible. The primary parameters for the results are identified, and the uncertainties quantified. The indicators, such as eco-points (EP), can be used for a comparison of the different products or processes.
Recommendations concerning the set goals can be derived, to achieve the targets of the maintenance of air quality, ground and water protection, or global warming potential reduction.
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