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Life-cycle assessment or life cycle assessment (LCA, also known as life-cycle analysis) is a methodology for assessing environmental impacts associated with all the stages of the life-cycle of a commercial product, process, or service. For instance, in the case of a manufactured product, environmental impacts are assessed from raw material extraction and processing (cradle), through the product's manufacture, distribution and use, to the recycling or final disposal of the materials composing it (grave).
An LCA study involves a thorough inventory of the energy and materials that are required across the industry value chain of the product, process or service, and calculates the corresponding emissions to the environment.LCA thus assesses cumulative potential environmental impacts. The aim is to document and improve the overall environmental profile of the product.
Widely recognized procedures for conducting LCAs are included in the 14000 series of environmental management standards of the International Organisation for Standardisation (ISO), in particular, in ISO 14040 and ISO 14044.
Criticisms have been leveled against the LCA approach, both in general and with regard to specific cases, e.g., in the consistency of the methodology, particularly with regard to system boundaries, and the susceptibility of particular LCAs to practitioner bias with regard to the decisions that they seek to inform.
Life-cycle assessment (LCA) is sometimes referred to synonymously as life-cycle analysis in the scholarly and agency report literatures. [ citation needed ]It is also sometimes referred to as "cradle-to-grave analysis".
As stated by the National Risk Management Research Laboratory of the EPA, "LCA is a technique to assess the environmental aspects and potential impacts associated with a product, process, or service, by:
Hence, it is a technique to assess environmental impacts associated with all the stages of a product's life from raw material extraction through materials processing, manufacture, distribution, use, repair and maintenance, and disposal or recycling. Designers use this process to help critique their products.[ citation needed ]
The goal of LCA is to compare the full range of environmental effects assignable to products and services by quantifying all inputs and outputs of material flows and assessing how these material flows affect the environment.This information is used to improve processes, support policy and provide a sound basis for informed decisions.
The term life-cycle refers to the notion that a fair, holistic assessment requires the assessment of raw-material production, manufacture, distribution, use and disposal including all intervening transportation steps necessary or caused by the product's existence.[ citation needed ]
There are two main types of LCA.[ according to whom? ][ citation needed ] Attributional LCAs seek to attribute the burdens associated with the production and use of a product, or with a specific service or process, at a point in time, typically in the recent past.[ citation needed ] Consequential LCAs seek to identify the environmental consequences of a decision or a proposed change in a system under study, and thus are oriented to the future and require that market and economic implications must be taken into account. A third type of LCA, termed "social LCA" is also under development This third type is a distinct approach to that is intended to assess potential social implications and impacts.[ citation needed ] Social Life Cycle Assessment (SLCA) is a useful tool for companies to identify and assess potential social impacts along the lifecycle of a product or service on various stakeholders (for example: workers, local communities, consumers). SLCA is framed by the UNEP/SETAC’s Guidelines for social life cycle assessment of products published in 2009 in Quebec. The tool builds on the ISO 26000:2010 Guidelines for Social Responsibility and the Global Reporting Initiative (GRI) Guidelines.
Some widely recognized procedures for LCA are included in the ISO 14000 series of environmental management standards, in particular, ISO 14040 and 14044. [ page needed ] [ page needed ] Greenhouse gas (GHG) product life cycle assessments can also comply with specifications such as Publicly Available Specification (PAS) 2050 and the GHG Protocol Life Cycle Accounting and Reporting Standard.
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According to standards in the ISO 14040 and 14044, an LCA is carried out in four distinct phases, [ page needed ] [ page needed ] as illustrated in the figure shown at the above right (at opening of the article). The phases are often interdependent, in that the results of one phase will inform how other phases are completed.[ citation needed ]
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An LCA starts with an explicit statement of the goal and scope of the study, which sets out the context of the study and explains how and to whom the results are to be communicated. This is a key step and the ISO standards require that the goal and scope of an LCA be clearly defined and consistent with the intended application.[ citation needed ] The goal and scope document, therefore, includes technical details that guide subsequent work:
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Life Cycle Inventory (LCI) analysis involves creating an inventory of flows from and to nature for a product system. Inventory flows include inputs of water, energy, and raw materials, and releases to air, land, and water. To develop the inventory, a flow model of the technical system is constructed using data on inputs and outputs. The flow model is typically illustrated with a flow chart that includes the activities that are going to be assessed in the relevant supply chain and gives a clear picture of the technical system boundaries. The input and output data needed for the construction of the model are collected for all activities within the system boundary, including from the supply chain (referred to as inputs from the technosphere).[ citation needed ]
The data must be related to the functional unit defined in the goal and scope definition. Data can be presented in tables and some interpretations can be made already at this stage. The results of the inventory is an LCI which provides information about all inputs and outputs in the form of elementary flow to and from the environment from all the unit processes involved in the study.[ citation needed ]
Inventory flows can number in the hundreds depending on the system boundary. For product LCAs at either the generic (i.e., representative industry averages) or brand-specific level, that data is typically collected through survey questionnaires. At an industry level, care has to be taken to ensure that questionnaires are completed by a representative sample of producers, leaning toward neither the best nor the worst, and fully representing any regional differences due to energy use, material sourcing or other factors. The questionnaires cover the full range of inputs and outputs, typically aiming to account for 99% of the mass of a product, 99% of the energy used in its production and any environmentally sensitive flows, even if they fall within the 1% level of inputs.[ citation needed ]
One area where data access is likely to be difficult is flows from the technosphere. The technosphere is more simply defined as the human-made world. Considered by geologists as secondary resources, these resources are in theory 100% recyclable; however, in a practical sense, the primary goal is salvage. [ citation needed ]For an LCI, these technosphere products (supply chain products) are those that have been produced by human and unfortunately those completing a questionnaire about a process which uses a human-made product as a means to an end will be unable to specify how much of a given input they use. Typically, they will not have access to data concerning inputs and outputs for previous production processes of the product. The entity undertaking the LCA must then turn to secondary sources if it does not already have that data from its own previous studies. National databases or data sets that come with LCA-practitioner tools, or that can be readily accessed, are the usual sources for that information. Care must then be taken to ensure that the secondary data source properly reflects regional or national conditions.
LCI methods include "process LCAs",[ clarification needed ][ citation needed ], economic input–output LCA (EIOLCA),[ clarification needed ][ citation needed ] and hybrid approaches.[ clarification needed ][ citation needed ]
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Inventory analysis is followed by a life-cyle impact assessment (LCIA). This phase of LCA is aimed at evaluating the significance of potential environmental impacts based on the life-cycle impact flow results.[ clarification needed ] Classical LCIAs consist of the following mandatory elements:[ citation needed ]
In many LCAs, characterization concludes the LCIA analysis,[ citation needed ] it is the last compulsory stage according to ISO 14044. [ page needed ] However, in addition to the above mandatory LCIA steps, other optional LCIA elements–normalization, grouping, and weighting–may be conducted depending on the goal and scope of the LCA study.[ citation needed ] In normalization, the results of the impact categories from the study are usually compared with the total impacts in the region of interest, e.g., the United States.[ citation needed ] Grouping consists of sorting and possibly ranking the impact categories.[ citation needed ] During weighting, the different environmental impacts are weighted relative to each other so that they can then be summed to get a single number for the total environmental impact.[ citation needed ] ISO 14044 generally advises against weighting, stating that "weighting, shall not be used in LCA studies intended to be used in comparative assertions intended to be disclosed to the public". [ page needed ] [ page needed ] This advice is often ignored, resulting in comparisons that can reflect a high degree of subjectivity as a result of weighting.[ citation needed ]
Life cycle impacts can also be categorized under the several phases of the development, production, use, and disposal of a product. Broadly speaking, these impacts can be divided into first impacts, use impacts, and end of life impacts. First impacts include extraction of raw materials, manufacturing (conversion of raw materials into a product), transportation of the product to a market or site, construction/installation, and the beginning of the use or occupancy. [ better source needed ] Use impacts include physical impacts of operating the product or facility (such as energy, water, etc.), and any maintenance, renovation, or repairs that are required to continue to use the product or facility.[ citation needed ] End of life impacts include demolition and processing of waste or recyclable materials.[ citation needed ]
Life-cycle interpretation is a systematic technique to identify, quantify, check, and evaluate information from the results of the life cycle inventory and/or the life cycle impact assessment. The results from the inventory analysis and impact assessment are summarized during the interpretation phase. The outcome of the interpretation phase is a set of conclusions and recommendations for the study. According to ISO 14040, [ page needed ] the interpretation should include:[ citation needed ]
A key purpose of performing life cycle interpretation is to determine the level of confidence in the final results and communicate them in a fair, complete, and accurate manner. Interpreting the results of an LCA is not as simple as "3 is better than 2, therefore Alternative A is the best choice".[ This quote needs a citation ] Interpretation begins with understanding the accuracy of the results, and ensuring they meet the goal of the study. This is accomplished by identifying the data elements that contribute significantly to each impact category, evaluating the sensitivity of these significant data elements, assessing the completeness and consistency of the study, and drawing conclusions and recommendations based on a clear understanding of how the LCA was conducted and the results were developed.[ citation needed ]
Specifically, as voiced by M.A. Curran, the goal of the LCA interpretation phase is to identify the alternative that has the least cradle-to-grave environmental negative impact on land, sea, and air resources.
This article needs attention from an expert in Environment. The specific problem is: to update the 2006 authoritative summary of uses, and to sift through the remaining weak description and example selections, to provide an encyclopedic summary of important applications based on the secondary literature.December 2019)(
At the time of a survey of LCA practitioners in 2006, LCA was being used to support business strategy and R&D (18% each, of total applications surveyed); other uses included LCA as an input to product or process design (15%), its use in education (13%), and its use for labeling or product declarations (11%).
It has been suggested[ by whom? ] that LCA will be continuously integrated into building practices through the development and implementation of appropriate tools—e.g., the European ENSLIC Building project guidelines —that guide practitioners in applying LCI[ clarification needed ] data methods to planning, design, and construction.[ citation needed ]
Major corporations all over the world[ peacock term ] are either undertaking LCA in house or commissioning studies, while governments support the development of national databases to support LCA.[ citation needed ] Of particular note is the growing use of LCA for ISO Type III labels called Environmental Product Declarations, defined as "quantified environmental data for a product with pre-set categories of parameters based on the ISO 14040 series of standards, but not excluding additional environmental information". Third-party certification plays a major role in today's industry,[ clarification needed ][ citation needed ] and third-party certified LCA-based labels provide an increasingly important basis for assessing the relative environmental merits of competing products.[ citation needed ] In particular, such independent certification is described as indicating a company's dedication to providing clients with safe and environmentally friendly products.[ citation needed ]
LCA also has major roles in environmental impact assessment, integrated waste management and pollution studies.[ citation needed ] Important recent studies applying LCA include:[ according to whom? ]
A life cycle analysis is only as accurate and valid as is its basis set of data.[ citation needed ] There are two fundamental types of LCA data–unit process data, and environmental input-output (EIO) data.[ citation needed ] Unit process data are derived from direct surveys of companies or plants producing the product of interest, carried out at a unit process level defined by the system boundaries for the study.[ citation needed ] EIO data are based on national economic input-output data.
Data validity is an ongoing concern for life cycle analyses.[ citation needed ] If LCA conclusions are to be valid, data used in the LCA inventory must accurate and valid, and so, with regard to validity, recent.[ citation needed ] Moreover, when comparing a pair of LCAs for different products, processes, or services, it is crucial that data of equivalent quality are available for the pair being compared. If one of the pair, e.g., a product, has a much higher availability of accurate and valid data, it cannot be justly compared to another product which has lower availability of such data.
With regard to the timeliness of data, it has been noted that data validity can be at odds with the time that data-gathering takes.[ citation needed ] Due to globalization and the pace of research and development, new materials and manufacturing methods are continually being introduced to the market, making it both important and difficult to identify and apply up-to-date information.[ citation needed ] For instance, in the consumer electronics sector, products such as cell phones may be redesigned as often as every 9 to 12 months, [ better source needed ] creating a need for rapid, ongoing data collection.[ citation needed ]
As noted above, the inventory in the LCA usually considers a number of stages including: materials extraction, processing and manufacturing, product use, and product disposal. [ citation needed ] For example, the most energy-intensive stage in the LCA of an aircraft or automobile product is during its use, as a result of fuel consumption during the product lifetime.[ citation needed ] An effective ways to increase fuel efficiency is to decrease vehicle weight; hence, aircraft and automobile manufacturers can decrease environmental impact through replacement of heavier materials with lighter ones (e.g., aluminium or carbon fiber-reinforced elements), all specifications and other costs being equal.[ citation needed ]If the most environmentally harmful of these stages can be determined, then impact on the environment can be efficiently reduced by focusing on making changes for that particular phase.
Data sources used in LCAs are typically large databases.[ citation needed ] It is not appropriate to compare two options if different data sources have been used to source the data. Common data sources include:[ according to whom? ][ citation needed ]
Calculations for impact can then be done by hand, but it is more usual to streamline the process by using software. This can range from a simple spreadsheet, where the user enters the data manually to a fully automated program, where the user is not aware of the source data.[ citation needed ]
Cradle-to-grave is the full Life Cycle Assessment from resource extraction ('cradle') to use phase and disposal phase ('grave'). For example, trees produce paper, which can be recycled into low-energy production cellulose (fiberised paper) insulation, then used as an energy-saving device in the ceiling of a home for 40 years, saving 2,000 times the fossil-fuel energy used in its production. After 40 years the cellulose fibers are replaced and the old fibers are disposed of, possibly incinerated. All inputs and outputs are considered for all the phases of the life cycle.[ citation needed ]
Cradle-to-gate is an assessment of a partial product life cycle from resource extraction (cradle) to the factory gate (i.e., before it is transported to the consumer). The use phase and disposal phase of the product are omitted in this case. Cradle-to-gate assessments are sometimes the basis for environmental product declarations (EPD) termed business-to-business EPDs.One of the significant uses of the cradle-to-gate approach compiles the life cycle inventory (LCI) using cradle-to-gate. This allows the LCA to collect all of the impacts leading up to resources being purchased by the facility. They can then add the steps involved in their transport to plant and manufacture process to more easily produce their own cradle-to-gate values for their products.
Cradle-to-cradle is a specific kind of cradle-to-grave assessment, where the end-of-life disposal step for the product is a recycling process. It is a method used to minimize the environmental impact of products by employing sustainable production, operation, and disposal practices and aims to incorporate social responsibility into product development.[ citation needed ] From the recycling process originate new, identical products (e.g., asphalt pavement from discarded asphalt pavement, glass bottles from collected glass bottles), or different products (e.g., glass wool insulation from collected glass bottles).[ citation needed ]
Allocation of burden for products in open loop production systems presents considerable challenges for LCA. Various methods, such as the avoided burden approach have been proposed to deal with the issues involved.[ citation needed ]
Gate-to-gate is a partial LCA looking at only one value-added process in the entire production chain. Gate-to-gate modules may also later be linked in their appropriate production chain to form a complete cradle-to-gate evaluation.
Well-to-wheel is the specific LCA used for transport fuels and vehicles. The analysis is often broken down into stages entitled "well-to-station", or "well-to-tank", and "station-to-wheel" or "tank-to-wheel", or "plug-to-wheel". The first stage, which incorporates the feedstock or fuel production and processing and fuel delivery or energy transmission, and is called the "upstream" stage, while the stage that deals with vehicle operation itself is sometimes called the "downstream" stage. The well-to-wheel analysis is commonly used to assess total energy consumption, or the energy conversion efficiency and emissions impact of marine vessels, aircraft and motor vehicles, including their carbon footprint, and the fuels used in each of these transport modes. [ citation needed ]WtW analysis is useful for reflecting the different efficiencies and emissions of energy technologies and fuels at both the upstream and downstream stages, giving a more complete picture of real emissions.
The well-to-wheel variant has a significant input on a model developed by the Argonne National Laboratory. The Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model was developed to evaluate the impacts of new fuels and vehicle technologies. The model evaluates the impacts of fuel use using a well-to-wheel evaluation while a traditional cradle-to-grave approach is used to determine the impacts from the vehicle itself. The model reports energy use, greenhouse gas emissions, and six additional pollutants: volatile organic compounds (VOCs), carbon monoxide (CO), nitrogen oxide (NOx), particulate matter with size smaller than 10 micrometre (PM10), particulate matter with size smaller than 2.5 micrometre (PM2.5), and sulfur oxides (SOx).
Quantitative values of greenhouse gas emissions calculated with the WTW or with the LCA method can differ, since the LCA is considering more emission sources. In example, while assessing the GHG emissions of a battery electric vehicle in comparison with a conventional internal combustion engine vehicle, the WTW (accounting only the GHG for manufacturing the fuels) finds out that an electric vehicle can save the 50–60% of GHG, [ clarification needed ].while an hybrid LCA-WTW method, considering also the GHG due to the manufacturing and the end of life of the battery gives GHG emission savings 10-13% lower, compared to the WTW
Economic input–output LCA (EIOLCA) involves use of aggregate sector-level data on how much environmental impact can be attributed to each sector of the economy and how much each sector purchases from other sectors.Such analysis can account for long chains (for example, building an automobile requires energy, but producing energy requires vehicles, and building those vehicles requires energy, etc.), which somewhat alleviates the scoping problem of process LCA; however, EIOLCA relies on sector-level averages that may or may not be representative of the specific subset of the sector relevant to a particular product and therefore is not suitable for evaluating the environmental impacts of products. Additionally the translation of economic quantities into environmental impacts is not validated.
While a conventional LCA uses many of the same approaches and strategies as an Eco-LCA, the latter considers a much broader range of ecological impacts. It was designed to provide a guide to wise management of human activities by understanding the direct and indirect impacts on ecological resources and surrounding ecosystems. Developed by Ohio State University Center for resilience, Eco-LCA is a methodology that quantitatively takes into account regulating and supporting services during the life cycle of economic goods and products. In this approach services are categorized in four main groups: supporting, regulating, provisioning and cultural services.
Exergy of a system is the maximum useful work possible during a process that brings the system into equilibrium with a heat reservoir. [ citation needed ]Wall clearly states the relation between exergy analysis and resource accounting. This intuition confirmed by DeWulf and Sciubba lead to Exergo-economic accounting and to methods specifically dedicated to LCA such as Exergetic material input per unit of service (EMIPS). The concept of material input per unit of service (MIPS) is quantified in terms of the second law of thermodynamics, allowing the calculation of both resource input and service output in exergy terms. This exergetic material input per unit of service (EMIPS) has been elaborated for transport technology. The service not only takes into account the total mass to be transported and the total distance, but also the mass per single transport and the delivery time.
Life cycle energy analysis (LCEA) is an approach in which all energy inputs to a product are accounted for, not only direct energy inputs during manufacture, but also all energy inputs needed to produce components, materials and services needed for the manufacturing process. An earlier term for the approach was energy analysis.[ citation needed ] With LCEA, the total life cycle energy input is established.[ citation needed ]
It is recognized that much energy is lost in the production of energy commodities themselves, such as nuclear energy, photovoltaic electricity or high-quality petroleum products. Net energy content is the energy content of the product minus energy input used during extraction and conversion, directly or indirectly. A controversial early result of LCEA claimed that manufacturing solar cells requires more energy than can be recovered in using the solar cell [ citation needed ]. The result was refuted. Currently, energy payback time of photovoltaic solar panels range from a few months to several years. Another new concept that flows from life cycle assessments is energy cannibalism. Energy cannibalism refers to an effect where rapid growth of an entire energy-intensive industry creates a need for energy that uses (or cannibalizes) the energy of existing power plants. Thus during rapid growth the industry as a whole produces no energy because new energy is used to fuel the embodied energy of future power plants. Work has been undertaken in the UK to determine the life cycle energy (alongside full LCA) impacts of a number of renewable technologies.
If materials are incinerated during the disposal process, the energy released during burning can be harnessed and used for electricity production. This provides a low-impact energy source, especially when compared with coal and natural gasWhile incineration produces more greenhouse gas emissions than landfills, the waste plants are well-fitted with regulated pollution control equipment to minimize this negative impact. A recent study comparing energy consumption and greenhouse gas emissions from landfills (without energy recovery) against incineration (with energy recovery) found incineration to be superior in all cases except for when landfill gas is recovered for electricity production.
Energy efficiency is arguably only one consideration in deciding which alternative process to employ, and should not be elevated as the only criterion for determining environmental acceptability.[ citation needed ] For example, a simple energy analysis does not take into account the renewability of energy flows or the toxicity of waste products. Incorporating "dynamic LCAs", e.g., with regard to renewable energy technologies—which use sensitivity analyses to project future improvements in renewable systems and their share of the power grid—may help mitigate this criticism. [ non-primary source needed ]
In recent years, the literature on life cycle assessment of energy technology has begun to reflect the interactions between the current electrical grid and future energy technology. Some papers have focused on energy life cycle,while others have focused on carbon dioxide (CO2) and other greenhouse gases. The essential critique given by these sources is that when considering energy technology, the growing nature of the power grid must be taken into consideration. If this is not done, a given class energy technology may emit more CO2 over its lifetime than it initially thought it would mitigate, with this most well documented in wind energy's case.
A problem that energy analysis method cannot resolve is that different energy forms—heat, electricity, chemical energy etc.—have different quality and value as a consequence of the two main laws of thermodynamics.[ clarification needed ][ citation needed ] According to the first law of thermodynamics, all energy inputs should be accounted with equal weight, whereas by the second law, diverse energy forms should be accounted for using different values.[ clarification needed ][ citation needed ] The conflict may be resolved in one of several ways:[ according to whom? ] the value differences between the energy inputs might be ignored, a value ratio may be arbitrarily assigned (e.g., that an input joule of electricity is 2.6-times more valuable than a joule of heat or fuel), the analysis may be supplemented by economic/cost analysis, or exergy, a thermodynamic measure of the quality of energy,[ citation needed ] may be used as the metric for the LCA (instead of energy).[ citation needed ]
Life cycle assessment is a powerful tool for analyzing commensurable aspects of quantifiable systems.[ according to whom? ][ citation needed ] Not every factor, however, can be reduced to a number and inserted into a model. Rigid system boundaries make accounting for changes in the system difficult. This is sometimes referred to as the boundary critique to systems thinking. The accuracy and availability of data can also contribute to inaccuracy. For instance, data from generic processes may be based on averages, unrepresentative sampling, or outdated results. Additionally, social implications of products are generally lacking in LCAs. Comparative life-cycle analysis is often used to determine a better process or product to use. However, because of aspects like differing system boundaries, different statistical information, different product uses, etc., these studies can easily be swayed in favor of one product or process over another in one study and the opposite in another study based on varying parameters and different available data. There are guidelines to help reduce such conflicts in results but the method still provides a lot of room for the researcher to decide what is important, how the product is typically manufactured, and how it is typically used.[ citation needed ]
An in-depth review of 13 LCA studies of wood and paper products [ citation needed ]found a lack of consistency in the methods and assumptions used to track carbon during the product lifecycle. A wide variety of methods and assumptions were used, leading to different and potentially contrary conclusions – particularly with regard to carbon sequestration and methane generation in landfills and with carbon accounting during forest growth and product use.
Industrial ecology (IE) is the study of material and energy flows through industrial systems. The global industrial economy can be modelled as a network of industrial processes that extract resources from the Earth and transform those resources into commodities which can be bought and sold to meet the needs of humanity. Industrial ecology seeks to quantify the material flows and document the industrial processes that make modern society function. Industrial ecologists are often concerned with the impacts that industrial activities have on the environment, with use of the planet's supply of natural resources, and with problems of waste disposal. Industrial ecology is a young but growing multidisciplinary field of research which combines aspects of engineering, economics, sociology, toxicology and the natural sciences.
Green building refers to both a structure and the application of processes that are environmentally responsible and resource-efficient throughout a building's life-cycle: from planning to design, construction, operation, maintenance, renovation, and demolition. This requires close cooperation of the contractor, the architects, the engineers, and the client at all project stages. The Green Building practice expands and complements the classical building design concerns of economy, utility, durability, and comfort. In doing so, the three dimensions of sustainability, i.e., planet, people and profit across the entire supply chain need to be considered.
Eco-labels and Green Stickers are labeling systems for food and consumer products. Ecolabels are voluntary, but green stickers are mandated by law; for example, in North America major appliances and automobiles use Energy Star. They are a form of sustainability measurement directed at consumers, intended to make it easy to take environmental concerns into account when shopping. Some labels quantify pollution or energy consumption by way of index scores or units of measurement, while others assert compliance with a set of practices or minimum requirements for sustainability or reduction of harm to the environment. Many ecolabels are focused on minimising the negative ecological impacts of primary production or resource extraction in a given sector or commodity through a set of good practices that are captured in a sustainability standard. Through a verification process, usually referred to as "certification", a farm, forest, fishery, or mine can show that it complies with a standard and earn the right to sell its products as certified through the supply chain, often resulting in a consumer-facing ecolabel.
Embodied energy is the sum of all the energy required to produce any goods or services, considered as if that energy was incorporated or 'embodied' in the product itself. The concept can be useful in determining the effectiveness of energy-producing or energy saving devices, or the "real" replacement cost of a building, and, because energy-inputs usually entail greenhouse gas emissions, in deciding whether a product contributes to or mitigates global warming. One fundamental purpose for measuring this quantity is to compare the amount of energy produced or saved by the product in question to the amount of energy consumed in producing it.
Downcycling, or cascading, is the recycling of waste where the recycled material is of lower quality and functionality than the original material. Often, this is due to the accumulation of tramp elements in secondary metals, which may exclude the latter from high-quality applications. For example, steel scrap from end-of-life vehicles is often contaminated with copper from wires and tin from coating. This contaminated scrap yields a secondary steel that does not meet the specifications for automotive steel and therefore, it is mostly applied in the construction sector.
An emission intensity is the emission rate of a given pollutant relative to the intensity of a specific activity, or an industrial production process; for example grams of carbon dioxide released per megajoule of energy produced, or the ratio of greenhouse gas emissions produced to gross domestic product (GDP). Emission intensities are used to derive estimates of air pollutant or greenhouse gas emissions based on the amount of fuel combusted, the number of animals in animal husbandry, on industrial production levels, distances traveled or similar activity data. Emission intensities may also be used to compare the environmental impact of different fuels or activities. In some case the related terms emission factor and carbon intensity are used interchangeably. The jargon used can be different, for different fields/industrial sectors; normally the term "carbon" excludes other pollutants, such as particulate emissions. One commonly used figure is carbon intensity per kilowatt-hour (CIPK), which is used to compare emissions from different sources of electrical power.
Carbon accounting or Greenhouse gas accounting refers generally to processes undertaken to "measure" amounts of carbon dioxide equivalents emitted by an entity. It is used by states, corporations and individuals to create the carbon credit commodity traded on carbon markets. Correspondingly, examples for products based upon forms of carbon accounting can be found in national inventories, corporate environmental reports or carbon footprint calculators. Likening sustainability measurement, as an instance of ecological modernisation discourses and policy, carbon accounting is hoped to provide a factual ground for carbon-related decision-making. However, social scientific studies of accounting challenge this hope, pointing to the socially constructed character of carbon conversion factors which cannot implement abstract accounting schemes into reality.
Cradle-to-cradle design is a biomimetic approach to the design of products and systems that models human industry on nature's processes, where materials are viewed as nutrients circulating in healthy, safe metabolisms. The term itself is a play on the popular corporate phrase "cradle to grave", implying that the C2C model is sustainable and considerate of life and future generations—from the birth, or "cradle", of one generation to the next generation, versus from birth to death, or "grave", within the same generation.
Material flow analysis (MFA), also referred to as substance flow analysis (SFA), is an analytical method to quantify flows and stocks of materials or substances in a well-defined system. MFA is an important tool to study the bio-physical aspects of human activity on different spatial and temporal scales. It is considered a core method of industrial ecology or anthropogenic, urban, social and industrial metabolism. MFA is used to study material, substance, or product flows across different industrial sectors or within ecosystems. MFA can also be applied to a single industrial installation, for example, for tracking nutrient flows through a waste water treatment plant. When combined with an assessment of the costs associated with material flows this business-oriented application of MFA is called material flow cost accounting. MFA is an important tool to study the circular economy and to devise material flow management. Since the 1990s, the number of publications related to material flow analysis has grown steadily. Peer-reviewed journals that publish MFA-related work include the Journal of Industrial Ecology, Ecological Economics, Environmental Science and Technology, and Resources, Conservation, and Recycling.
Life-cycle engineering (LCE) is a sustainability-oriented engineering methodology that takes into account the comprehensive technical, environmental, and economic impacts of decisions within the product life cycle. Alternatively it can be defined as “sustainability-oriented product development activities within the scope of one to several product life cycles.” LCE requires analysis to quantify sustainability, setting appropriate targets for environmental impact. The application of complementary methodologies and technologies enables engineers to apply LCE to fulfill environmental objectives.
Design for the Environment (DfE) is a design approach to reduce the overall human health and environmental impact of a product, process or service, where impacts are considered across its life cycle. Different software tools have been developed to assist designers in finding optimized products or processes/services. DfE is also the original name of a United States Environmental Protection Agency (EPA) program, created in 1992, that works to prevent pollution, and the risk pollution presents to humans and the environment. The program provides information regarding safer chemical formulations for cleaning and other products. EPA renamed its program "Safer Choice" in 2015.
Sustainable packaging is the development and use of packaging which results in improved sustainability. This involves increased use of life cycle inventory (LCI) and life cycle assessment (LCA) to help guide the use of packaging which reduces the environmental impact and ecological footprint. It includes a look at the whole of the supply chain: from basic function, to marketing, and then through to end of life (LCA) and rebirth. Additionally, an eco-cost to value ratio can be useful The goals are to improve the long term viability and quality of life for humans and the longevity of natural ecosystems. Sustainable packaging must meet the functional and economic needs of the present without compromising the ability of future generations to meet their own needs. Sustainability is not necessarily an end state but is a continuing process of improvement.
An economic input-output life-cycle assessment, or EIO-LCA involves the use of aggregate sector-level data to quantify the amount of environmental impact that can be directly attributed to each sector of the economy and how much each sector purchases from other sectors in producing its output. Combining such data sets can enable accounting for long chains, which somewhat alleviates the scoping problem of traditional life-cycle assessments. EIO-LCA analysis traces out the various economic transactions, resource requirements and environmental emissions required for producing a particular product or service.
Eco-costs are the costs of the environmental burden of a product on the basis of prevention of that burden. They are the costs which should be made to reduce the environmental pollution and materials depletion in our world to a level which is in line with the carrying capacity of our earth.
Measurement of life-cycle greenhouse gas emissions involves calculating the global-warming potential of energy sources through life-cycle assessment. These are usually sources of only electrical energy but sometimes sources of heat are evaluated. The findings are presented in units of global warming potential per unit of electrical energy generated by that source. The scale uses the global warming potential unit, the carbon dioxide equivalent, and the unit of electrical energy, the kilowatt hour (kWh). The goal of such assessments is to cover the full life of the source, from material and fuel mining through construction to operation and waste management.
Sustainable products are those products that provide environmental, social and economic benefits while protecting public health and environment over their whole life cycle, from the extraction of raw materials until the final disposal.
Life cycle thinking is an approach to becoming mindful of how everyday life affects the environment. This approach evaluates how both consuming products and engaging in activities impacts the environment but it not only evaluates them at one single step, but takes a holistic picture of an entire product or activity system.
Green engineering approaches the design of products and processes by applying financially and technologically feasible principles to achieve one or more of the following goals: (1) decrease in the amount of pollution that is generated by a construction or operation of a facility, (2) minimization of human population exposure to potential hazards, (3) improved uses of matter and energy throughout the life cycle of the product and processes, and (4) maintaining economic efficiency and viability. Green engineering can an overarching framework for all design disciplines.
Environmental systems analysis (ESA) is a systematic and systems based approach for describing human actions impacting on the natural environment to support decisions and actions aimed at perceived current or future environmental problems. Impacts of different types of objects are studied that ranges from projects, programs and policies, to organizations, and products. Environmental systems analysis encompasses a family of environmental assessment tools and methods, including life cycle assessment (LCA), material flow analysis (MFA) and substance flow analysis (SFA), and environmental impact assessment (EIA), among others.
Michael Wang is a distinguished fellow, a senior scientist, and director of the Systems Assessment Center of the Energy Systems Division at the U.S. Department of Energy’s (DOE) Argonne National Laboratory. He is also a faculty associate in the Energy Policy Institute at The University of Chicago; a senior fellow at the Northwestern-Argonne Institute of Science and Engineering at Northwestern University; and a guest professor in China’s Shanghai Jiao Tong University.
Life cycle analysis (LCA) is a method used to evaluate the environmental impact of a product through its life cycle encompassing extraction and processing of the raw materials, manufacturing, distribution, use, recycling, and final disposal.. See also this list of references to the term.
LCA is a technique to assess the environmental aspects and potential impacts associated with a product, process, or service, by: / * Compiling an inventory of relevant energy and material inputs and environmental releases/ * Evaluating the potential environmental impacts associated with identified inputs and releases / * Interpreting the results to help you make a more informed decision
It is very important to first set the goal of the life cycle analysis or assessment. In the conceptual design stage, the goal in general will be identifying the major environmental impacts of the reference process and showing how the new design reduces these impacts