Life-cycle assessment
Life-cycle assessment (LCA) is a comprehensive method for evaluating the environmental impacts of a product or service throughout its entire life cycle, from raw material extraction to disposal. This "cradle-to-grave" approach helps uncover hidden environmental consequences related to resource consumption, emissions, and waste generation. Originating from environmental discussions in the late 1960s, LCA gained traction during the global oil crises, evolving into a critical tool for product-oriented environmental policies.
An LCA consists of four phases: defining the goal and scope of the assessment, conducting an inventory analysis of resource flows, performing an impact assessment of those flows, and interpreting the results. The assessment considers various environmental impacts, including ecological effects, human health consequences, and resource use, often subdivided into specific categories such as global warming and ozone depletion. While LCA is widely utilized across different sectors, it has faced criticism for inconsistencies in data and methodology, particularly regarding system boundaries and social implications. Overall, LCA serves as a valuable decision-support tool for industries, governments, and organizations aiming to minimize environmental harm.
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Life-cycle assessment
DEFINITION: Technique for investigating and evaluating the environmental consequences arising from the provision of a product or service
Life-cycle assessment is a method of considering the “cradle-to-grave” environmental impacts a product has during its entire life cycle—from raw material acquisition through production, use, consumption, and reuse or final disposal. The technique has the advantage of revealing hidden environmental impacts.
The term “life-cycle assessment” (LCA) is applied to a whole family of environmental assessment tools. The driving force behind the first LCA was an environmental debate about and packaging in the United States during the late 1960s. The first LCAs compared the resource consumption and emissions of beverage cans, plastic bottles, and refillable glass bottles. During the global oil crises of 1973 and 1979 the focus of LCAs shifted to the analysis of different substitutes. With growing environmental awareness LCA became an attractive methodology for product-oriented environmental policies in several countries.
During the 1990s the first attempt to establish an international standard for LCAs was undertaken by the Society of Environmental Toxicology and Chemistry (SETAC). This effort outlined the way for a systematic application of LCA as a decision support tool used in industry, government, and nongovernmental organizations. During the late 1990s the International Organization for Standardization (ISO) released its first international guidelines for LCA practitioners.
According to ISO standards, an LCA study consists of four distinct phases: goal and scope definition, inventory analysis, impact assessment, and interpretation. In the goal and scope phase, the product and the purpose of the study is set. Reasons for carrying out LCAs vary; an LCA may be undertaken to compare the environmental impacts of two different products, for example, or to support product development. According to the goal and scope, the system boundaries (boundaries in relation to natural or technical systems, geographic boundaries, time horizon) for the assessment are determined. The second phase, the life-cycle inventory (LCI) analysis, is a process of quantifying the environmentally relevant flows for the entire life cycle of the product. Inputs include energy, raw materials, and ancillary requirements; outputs are atmospheric emissions, waterborne emissions, solid wastes, and other releases. Inputs and outputs are represented in a flowchart. The third phase, called life-cycle impact assessment (LCIA), consists of the evaluation of potential environmental consequences of the inputs and outputs quantified in the inventory analysis.
The general categories of impacts considered in an LCA are ecological consequences, human health effects, and resource use. For practical reasons these three categories are normally divided into more specific impact categories, such as global warming, ozone depletion, resource depletion, acidification, photochemical smog, human health, land and water use, or terrestrial toxicity. The LCI parameters are sorted and assigned to the various categories. For comparison between LCI results within a category, equivalency factors are used. In the global warming category, for example, different greenhouse gases can be expressed in terms of carbon dioxide equivalents. In a forth and final step, the results of the LCI and LCIA are analyzed, and conclusions are drawn regarding the environmental impacts of the investigated product or service.
The application of LCA is widespread and ranges from the analysis of waste management to production processes and different sorts of consumer goods. Despite the popularity of LCA and the international standardization of the process, LCA has received some criticism for a lack of consistency. Possible sources of inconsistency are variations in system boundaries and cutoff criteria, as well as the quality and availability of data. Critics have also noted that any assessment of the social implications of products is generally lacking in LCA.
Bibliography
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Dietz, Thomas, and Paul C. Stern, eds. Public Participation in Environmental Assessment and Decision Making. Washington, D.C.: National Academies Press, 2008.
Hellwig, Stefanie, et al. "Life-Cycle Assessment to Guide Solutions for the Triple Planetary Crisis." Nature Reviews Earth & Environment, vol. 4, 7 Apr. 2023, pp. 471-486, doi.org/10.1038/s43017-023-00449-2. Accessed 20 July 2024.
Levy, Geoffrey M., ed. Packaging, Policy, and the Environment. New York: Aspen, 2000.