HOME

TheInfoList



OR:

Life cycle assessment or LCA (also known as life cycle analysis) is a
methodology In its most common sense, methodology is the study of research methods. However, the term can also refer to the methods themselves or to the philosophical discussion of associated background assumptions. A method is a structured procedure for bri ...
for assessing environmental impacts associated with all the stages of the life cycle of a commercial product,
process A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management *Business process, activities that produce a specific se ...
, or service. For instance, in the case of a
manufactured product A final good or consumer good is a final product ready for sale that is used by the consumer to satisfy current wants or needs, unlike a intermediate good, which is used to produce other goods. A microwave oven or a bicycle is a final good, but t ...
,
environmental impacts Environmental issues are effects of human activity on the biophysical environment, most often of which are harmful effects that cause environmental degradation. Environmental protection is the practice of protecting the natural environment on t ...
are assessed from
raw material A raw material, also known as a feedstock, unprocessed material, or primary commodity, is a basic material that is used to produce goods, finished goods, energy, or intermediate materials that are feedstock for future finished products. As feedst ...
extraction and processing (cradle), through the product's manufacture, distribution and use, to the
recycling Recycling is the process of converting waste materials into new materials and objects. The recovery of energy from waste materials is often included in this concept. The recyclability of a material depends on its ability to reacquire the p ...
or final disposal of the materials composing it (grave). An LCA study involves a thorough inventory of the
energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...
and materials that are required across the industry
value chain A value chain is a progression of activities that a firm operating in a specific industry performs in order to deliver a valuable product (i.e., good and/or service) to the end customer. The concept comes through business management and was firs ...
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 Environmental resource management is the management of the interaction and impact of human societies on the environment. It is not, as the phrase might suggest, the management of the environment itself. Environmental resources management aims ...
standards of the
International Organization for Standardization The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Ar ...
(ISO), in particular, in ISO 14040 and ISO 14044. ISO 14040 provides the 'principles and framework' of the Standard, while ISO 14044 provides an outline of the 'requirements and guidelines'. Generally, ISO 14040 was written for a managerial audience and ISO 14044 for practitioners. As part of the introductory section of ISO 14040, LCA has been defined as the following:
LCA studies the environmental aspects and potential impacts throughout a product's life cycle (i.e., cradle-to-grave) from raw materials acquisition through production, use and disposal. The general categories of environmental impacts needing consideration include resource use, human health, and ecological consequences.
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 Bias is a disproportionate weight ''in favor of'' or ''against'' an idea or thing, usually in a way that is closed-minded, prejudicial, or unfair. Biases can be innate or learned. People may develop biases for or against an individual, a group, ...
with regard to the decisions that they seek to inform). Without a formal set of requirements and guidelines, an LCA can be completed based on a practitioner's views and believed methodologies. In turn, an LCA completed by 10 different parties could yield 10 different results. The ISO LCA Standard aims to normalize this; however, the guidelines are not overly restrictive and 10 different answers may still be generated.


Definition, synonyms, goals, and purpose

Life cycle assessment (LCA) is sometimes referred to synonymously as life cycle analysis in the scholarly and agency report literatures.. Also, due to the general nature of an LCA study of examining the life cycle impacts from raw material extraction (cradle) through disposal (grave), it is sometimes referred to as "cradle-to-grave analysis". As stated by the National Risk Management Research Laboratory of the
EPA The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
, "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". 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. The results are used to help decision-makers select products or processes that result in the least impact to the environment by considering an entire product system and avoiding sub-optimization that could occur if only a single process were used. Therefore, 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 Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations * Probability distribution, the probability of a particular value or value range of a vari ...
, use and disposal including all intervening transportation steps necessary or caused by the product's existence. Despite attempts to standardize LCA, results from different LCAs are often contradictory, therefore it is unrealistic to expect these results to be unique and objective. Thus, it should not be considered as such, but rather as a family of methods attempting to quantify results through a different point-of-view. Among these methods are two main types: Attributional LCA and Consequential LCA. Attributional LCAs seek to attribute the burdens associated with the production and use of a product, or with a specific service or process, for an identified temporal period. 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. In other words, Attributional LCA "attempts to answer 'how are things (i.e. pollutants, resources, and exchanges among processes) flowing within the chosen temporal window?', while Consequential LCA attempts to answer 'how will flows beyond the immediate system change in response to decisions?" A third type of LCA, termed "social LCA", is also under development and is a distinct approach to that is intended to assess potential social and socio-economic implications and impacts.Guidelines for Social Life Cycle Assessment of Products
, United Nations Environment Programme, 2009.
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 th
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. The limitations of LCA to focus solely on the ecological aspects of sustainability, and not the economical or social aspects, distinguishes it from product line analysis (PLA) and similar methods. This limitation was made deliberately to avoid method overload but recognizes these factors should not be ignored when making product decisions. Some widely recognized procedures for LCA are included in the ISO 14000 series of environmental management standards, in particular, ISO 14040 and 14044.E.g., see For the PDF of the 1997 version
see this Stanford University course reading
E.g., see
Greenhouse gas A greenhouse gas (GHG or GhG) is a gas that Absorption (electromagnetic radiation), absorbs and Emission (electromagnetic radiation), emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse ...
(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.


Main ISO phases of LCA

According to standards in the ISO 14040 and 14044, an LCA is carried out in four distinct phases, 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. Therefore, none of the stages should be considered finalized until the entire study is complete.


Goal and Scope

The ISO LCA Standard requires a series of parameters to be quantitatively and qualitatively expressed, which are occasionally referred to as study design parameters (SPDs). The two main SPDs for an LCA are the Goal and Scope, both which must be explicitly stated. It is recommended that a study uses the keywords represented in the Standard when documenting these details (e.g., "The goal of the study is...") to make sure there is no confusion and ensure the study is being interpreted for its intended use. Generally, an LCA study begins with an explicit statement of the goal, which sets out the context of the study and explains how and to whom the results are to be communicated. Per ISO guidelines, the goal must unambiguously state the following items: # The intended application # Reasons for carrying out the study # The audience # Whether the results will be used in a comparative assertion released publicly The goal should also be defined with the commissioner for the study, and it is recommended a detailed description for why the study is being carried out is acquired from the commissioner. Following the goal, the scope must be defined by outlining the qualitative and quantitative information included in the study. Unlike the goal, which may only include a few sentences, the scope often requires multiple pages. It is set to describe the detail and depth of the study and demonstrate that the goal can be achieved within the stated limitations. Under the ISO LCA Standard guidelines, the scope of the study should outline the following: * Product System, which is a collection of processes (activities that transform inputs to outputs) that are needed to perform a specified function and are within the system boundary of the study. It is representative of all the processes in the life cycle of a product or process. * Functional Unit, which defines precisely what is being studied, quantifies the service delivered by the system, provides a reference to which the inputs and outputs can be related, and provides a basis for comparing/analyzing alternative goods or services. The functional unit is a very important component of LCA and needs to be clearly defined. It is used as a basis for selecting one or more product systems that can provide the function. Therefore, the functional unit enables different systems to be treated as functionally equivalent. The defined functional unit should be quantifiable, include units, consider temporal coverage, and not contain product system inputs and outputs (e.g., kg emissions). Another way to look at it is by considering the following questions: *# What? *# How much? *# For how long / how many times? *# Where? *# How well? * Reference Flow, which is the amount of product or energy that is needed to realize the functional unit. Typically, the reference flow is different qualitatively and quantitatively for different products or systems across the same reference flow; however, there are instances where they can be the same. * System Boundary, which delimits which processes should be included in the analysis of a product system, including whether the system produces any co-products that must be accounted for by system expansion or allocation. The system boundary should be in accordance with the stated goal of the study. * Assumptions and Limitations, which includes any assumptions or decisions made throughout the study that may influence the final results. It is important these are made transmitted as the omittance may result in misinterpretation of the results. Additional assumptions and limitations necessary to accomplish the project are often made throughout the project and should recorded as necessary. * Data Quality Requirements, which specify the kinds of data that will be included and what restrictions. According to ISO 14044, the following data quality considerations should be documented in the scope: *# Temporal Coverage *# Geographical Coverage *# Technological Coverage *# Precision, completeness, and representativeness of the data *# Consistency and reproducibility of the methods used in the study *# Sources of Data *# Uncertainty of information and any recognized data gaps * Allocation Procedure, which is used to partition the inputs and outputs of a product and is necessary for processes that produce multiple products, or co-products. This is also known as multifunctionality of a product system. ISO 14044 presents a hierarchy of solutions to deal with multifunctionality issues, as the choice of allocation method for co-products can significantly impact results of an LCA. The hierarchy methods are as follows: *# Avoid Allocation by Sub-Division - this method attempts to disaggregate the unit process into smaller sub-processes in order to separate the production of the product from the production of the co-product. *# Avoid Allocation through System Expansion (or substitution) - this method attempts to expand the process of the co-product with the most likely way of providing the secondary function of the determining product (or reference product). In other words, by expanding the system of the co-product in the most likely alternative way of producing the co-product independently (System 2). The impacts resulting from the alternative way of producing the co-product (System 2) are then subtracted from the determining product to isolate the impacts in System 1. *# Allocation (or partition) based on Physical Relationship - this method attempts to divide inputs and outputs and allocate them based on physical relationships between the products (e.g., mass, energy-use, etc.). *# Allocation (or partition) based on Other Relationship (non-physical) - this method attempts to divide inputs and outputs and allocate them based on non-physical relationships (e.g., economic value). * Impact Assessment, which includes an outline of the impact categories identified under interest for the study, and the selected methodology used to calculate the respective impacts. Specifically, life cycle inventory data is translated into environmental impact scores, which might include such categories as human
toxicity Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...
,
smog Smog, or smoke fog, is a type of intense air pollution. The word "smog" was coined in the early 20th century, and is a portmanteau of the words ''smoke'' and '' fog'' to refer to smoky fog due to its opacity, and odor. The word was then inte ...
,
global warming In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
, and
eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...
. As part of the scope, only an overview needs to be provided, as the main analysis on the impact categories is discussed in the Life Cycle Impact Assessment (LCIA) phase of the study. * Documentation of Data, which is the explicit documentation of the inputs/outputs (individual flows) used within the study. This is necessary as most analyses do not consider all inputs and outputs of a product system, so this provides the audience with a transparent representation of the selected data. It also provides transparency for why the system boundary, product system, functional unit, etc. was chosen.


Life Cycle Inventory (LCI)

Life Cycle Inventory (LCI) analysis involves creating an inventory of flows from and to nature (ecosphere) for a product system. It is the process of quantifying raw material and energy requirements, atmospheric emissions, land emissions, water emissions, resource uses, and other releases over the life cycle of a product or process. In other words, it is the aggregation of all elementary flows related to each unit process within a product system. To develop the inventory, it is often recommended to start with a flow model of the technical system using data on inputs and outputs of the product system. The flow model is typically illustrated with a flow diagram 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. Generally, the more detailed and complex the flow diagram, the more accurate the study and results. The input and output data needed for the construction of the model is collected for all activities within the system boundary, including from the supply chain (referred to as inputs from the technosphere). According to ISO 14044, an LCI should be documented using the following steps: # Preparation of data collection based on goal and scope # Data Collection # Data Validation (even if using another work's data) # Data Allocation (if needed) # Relating Data to the Unit Process # Relating Data to the Functional Unit # Data Aggregation As referenced in the ISO 14044 standard, the data must be related to the functional unit, as well as the goal and scope. However, since the LCA stages are iterative in nature, the data collection phase may cause the goal or scope to change. Conversely, a change in the goal or scope during the course of the study may cause additional collection of data or removal or previously collected data in the LCI. The output of an LCI is a compiled inventory of elementary flows from all of the processes in the studied product system(s). The data is typically detailed in charts and requires a structured approach due to its complex nature. When collecting the data for each process within the system boundary, the ISO LCA standard requires the study to measure or estimate the data in order to quantitatively represent each process in the product system. Ideally, when collecting data, a practitioner should aim to collect data from primary sources (e.g., measuring inputs and outputs of a process on-site or other physical means). Questionnaire are frequently used to collect data on-site and can even be issued to the respective manufacturer or company to complete. Items on the questionnaire to be recorded may include: # Product for Data Collection # Data Collector and Date # Period of Data Collection # Detailed Explanation of the Process # Inputs (raw materials, ancillary materials, energy, transportation) # Outputs (emissions to air, water, and land) # Quantity and Quality of each input and output Oftentimes, the collection of primary data may be difficult and deemed proprietary or confidential by the owner. An alternative to primary data is secondary data, which is data that comes from LCA databases, literature sources, and other past studies. With secondary sources, it is often you find data that is similar to a process but not exact (e.g., data from a different country, slightly different process, similar but different machine, etc.). As such, it is important to explicitly document the differences in such data. However, secondary data is not always inferior to primary data. For example, referencing another work's data in which the author used very accurate primary data. Along with primary data, secondary data should document the source, reliability, and temporal, geographical, and technological representativeness. When identifying the inputs and outputs to document for each unit process within the product system of an LCI, a practitioner may come across the instance where a process has multiple input streams or generate multiple output streams. In such case, the practitioner should allocate the flows based on the "Allocation Procedure" outlined in the previous "Goal and Scope" section of this article. The technosphere is more simply defined as the human-made world, and considered by geologists as secondary resources, these resources are in theory 100% recyclable; however, in a practical sense, the primary goal is salvage. For an LCI, these technosphere products (supply chain products) are those that have been produced by humans, including products such as forestry, materials, and energy flows. 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-based LCAs", economic input–output LCA (
EIOLCA 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 purchas ...
), and hybrid approaches. Process-based LCA is a bottom-up LCI approach the constructs an LCI using knowledge about industrial processes within the life cycle of a product, and the physical flows connecting them. EIOLCA is a top-down approach to LCI and uses information on elementary flows associated with one unit of economic activity across different sectors. This information is typically pulled from government agency national statistics tracking trade and services between sectors. Hybrid LCA is a combination of process-based LCA and EIOLCA. The quality of LCI data is typically evaluated with the use of a pedigree matrix. Different pedigree matrices are available, but all contain a number of data quality indicators and a set of qualitative criteria per indicator. There is another hybrid approach integrates the widely used, semi-quantitative approach that uses a pedigree matrix, into a qualitative analysis to better illustrate the quality of LCI data for non-technical audiences, in particular policymakers.


Life Cycle Impact Assessment (LCIA)

Life Cycle Inventory analysis is followed by a life cycle impact assessment (LCIA). This phase of LCA is aimed at evaluating the potential environmental and human health impacts resulting from the elementary flows determined in the LCI. The ISO 14040 and 14044 standards require the following mandatory steps for completing an LCIA: Mandatory * Selection of impaction categories, category indicators, and characterization models. The ISO Standard requires that a study selects multiple impacts that encompass "a comprehensive set of environmental issues". The impacts should be relevant to the geographical region of the study and justification for each chosen impact should be discussed. Often times in practice, this is completed by choosing an already existing LCIA method (e.g., TRACI, ReCiPe, AWARE, etc.). * Classification of inventory results. In this step, the LCI results are assigned to the chosen impact categories based on their known environmental effects. In practice, this is often completed using LCI databases or LCA software. Common impact categories include Global Warming, Ozone Depletion, Acidification, Human Toxicity, etc. * Characterization, which quantitatively transforms the LCI results within each impact category via "characterization factors" (also referred to as equivalency factors) to create "impact category indicators." In other words, this step is aimed at answering "how much does each result contribute to the impact category?" A main purpose of this step is to convert all classified flows for an impact into common units for comparison. For example, for Global Warming Potential, the unit is generally defined as CO2-equiv or CO2-e (CO2 equivalents) where CO2 is given a value of 1 and all other units are converted respective to their related impact. In many LCAs, characterization concludes the LCIA analysis, as it is the last compulsory stage according to ISO 14044. However, the ISO Standard provides the following optional steps to be taken in addition to the aforementioned mandatory steps: Optional * Normalization of results. This step aims to answer "Is that a lot?" by expressing the LCIA results in respect to a chosen reference system. A separate reference value is often chosen for each impact category, and the rationale for the step is to provide temporal and spatial perspective and to help validate the LCIA results. Standard references are typical impacts per impact category per: geographical zone, inhabitant of geographical zone (per person), industrial sector, or another product system or baseline reference scenario. * Grouping of LCIA results. This step is accomplished by sorting or ranking the LCIA results (either characterized or normalized depending on the prior steps chosen) into a single group or several groups as defined within the goal and scope. However, grouping is subjective and may be inconsistent across studies. * Weighting of impact categories. This step aims to determine the significance of each category and how important it is relative to the others. It allows studies to aggregate impact scores into a single indicator for comparison. Weighting is highly subjective and as it is often decided based on the interested parties' ethics. There are three main categories of weighting methods: the panel method, monetization method, and target method. 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". If a study decides to weight results, then the weighted results should always be reported together with the non-weighted results for transparency. 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. 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. End of life impacts include demolition and processing of waste or recyclable materials.


Interpretation

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 14043, the interpretation should include the following: * Identification of significant issues based on the results of the LCI and LCIA phases of an LCA * Evaluation of the study considering completeness, sensitivity and consistency checks * Conclusions, limitations and recommendations 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". 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. 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.


LCA uses

LCA was primarily used as a comparison tool, providing informative information on the environmental impacts of a product and comparing it to available alternatives. Its potential applications expanded to include marketing, product design, product development, strategic planning, consumer education, ecolabeling and government policy. ISO specifies three types of classification in regard to standards and environmental labels: * Type I environmental labelling requires a third-party certification process to verify a products compliance against a set of criteria, according to ISO 14024. * Type II environmental labels are self-declared environmental claims, according to ISO 14021. * Type III environmental declaration, also known as environmental product declaration (EPD), uses LCA as a tool to report the environmental performance of a product, while conforming to the ISO standards 14040 and 14044. EPDs provide a level of transparency that is being increasingly demanded through policies and standards around the world. They are used in the built environment as a tool for experts in the industry to compose whole building life cycle assessments more easily, as the environmental impact of individual products are known.


Data analysis

A life cycle analysis is only as accurate and valid as is its basis set of
data In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted ...
. There are two fundamental types of LCA data–unit process data, and environmental input-output (EIO) data. A unit process data collects data around a single industrial activity and its product(s), including resources used from the environment and other industries, as well as its generated emissions throughout its life cycle. EIO data are based on national economic input-output data. In 2001, ISO published a technical specification on data documentation, describing the format for life cycle inventory data (ISO 14048). The format includes three areas: process, modeling and validation, and administrative information. When comparing LCAs, the data used in each LCA should be of ''equivalent'' quality, since no just comparison can be done if one product has a much higher availability of accurate and valid data, as compared to another product which has lower availability of such data. Moreover, time horizon is a sensitive parameter and was shown to introduce inadvertent bias by providing one perspective on the outcome of LCA, when comparing the toxicity potential between petrochemicals and biopolymers for instance. Therefore, conducting sensitivity analysis in LCA are important to determine which parameters considerably impact the results, and can also be used to identify which parameters cause uncertainties. Data sources used in LCAs are typically large databases. Common data sources include: * soca * EuGeos' 15804-IA * NEEDS * ecoinvent * PSILCA * ESU World Food * GaBi * ELCD * LC-Inventories.ch * Social Hotspots * ProBas * bioenergiedat * Agribalyse * USDA * Ökobaudat * Agri-footprint * Comprehensive Environmental Data Archive (CEDA) 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. When an LCA is done on a product across all stages, the stage with the highest environmental impact can be determined and altered. For example, woolen-garment was evaluated on its environmental impacts during its production, use and end-of-life, and identified the contribution of fossil fuel energy to be dominated by wool processing and GHG emissions to be dominated by wool production. However, the most influential factor was the number of garment wear and length of garment lifetime, indicating that the consumer has the largest influence on this products' overall environmental impact.


Variants


Cradle-to-grave or life cycle assessment

Cradle-to-grave is the full Life Cycle Assessment from resource extraction ('cradle'), to manufacturing, usage, and maintenance, all the way through to its disposal phase ('grave'). For example, trees produce paper, which can be recycled into low-energy production
cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...
(fiberised paper)
insulation Insulation may refer to: Thermal * Thermal insulation, use of materials to reduce rates of heat transfer ** List of insulation materials ** Building insulation, thermal insulation added to buildings for comfort and energy efficiency *** Insulated ...
, 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 Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...
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.


Cradle-to-gate

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 An Environmental Product Declaration (EPD) is defined by International Organization for Standardization (ISO) 14025 as a Type III declaration that "quantifies environmental information on the life cycle of a product to enable comparisons between p ...
(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 or closed loop production

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. 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). 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.


Gate-to-gate

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

Well-to-wheel (WtW) is the specific LCA used for
transport Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land (rail and road), water, cable, pipeline, an ...
fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but ...
s 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 Energy conversion efficiency (''η'') is the ratio between the useful output of an energy conversion machine and the input, in energy terms. The input, as well as the useful output may be chemical, electric power, mechanical work, light (radia ...
and
emission Emission may refer to: Chemical products * Emission of air pollutants, notably: **Flue gas, gas exiting to the atmosphere via a flue ** Exhaust gas, flue gas generated by fuel combustion ** Emission of greenhouse gases, which absorb and emit radi ...
s impact of
marine vessel Any vehicle used in or on water as well as underwater, including boats, ships, hovercraft and submarines, is a watercraft, also known as a water vessel or waterborne vessel. A watercraft usually has a propulsive capability (whether by sail, o ...
s,
aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...
and
motor vehicle A motor vehicle, also known as motorized vehicle or automotive vehicle, is a self-propelled land vehicle, commonly wheeled, that does not operate on Track (rail transport), rails (such as trains or trams) and is used for the transportation of pe ...
s, including their
carbon footprint A carbon footprint is the total greenhouse gas (GHG) emissions caused by an individual, event, organization, service, place or product, expressed as carbon dioxide equivalent (CO2e). Greenhouse gases, including the carbon-containing gases carbo ...
, and the fuels used in each of these transport modes. 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 Argonne National Laboratory is a science and engineering research United States Department of Energy National Labs, national laboratory operated by University of Chicago, UChicago Argonne LLC for the United States Department of Energy. The facil ...
. 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 Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and lar ...
, and six additional pollutants: volatile organic compounds (VOCs),
carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...
(CO),
nitrogen oxide Nitrogen oxide may refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds: Charge-neutral *Nitric oxide (NO), nitrogen(II) oxide, or nitrogen monoxide *Nitrogen dioxide (), nitrogen(IV) oxide * Nitrogen trioxide (), or n ...
(NOx),
particulate matter Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The ter ...
with size smaller than 10 micrometer (PM10), particulate matter with size smaller than 2.5 micrometer (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. For example, while assessing the GHG emissions of a
battery electric vehicle A battery electric vehicle (BEV), pure electric vehicle, only-electric vehicle, fully electric vehicle or all-electric vehicle is a type of electric vehicle (EV) that exclusively uses chemical energy stored in rechargeable battery packs, wi ...
in comparison with a conventional internal combustion engine vehicle, the WTW (accounting only the GHG for manufacturing the fuels) concludes that an electric vehicle can save around 50–60% of GHG. On the other hand, using a hybrid LCA-WTW method, concludes that GHG emission savings are 10-13% lower than the WTW results, as the GHG due to the manufacturing and the end of life of the battery are also considered.


Economic input–output life cycle assessment

Economic input–output LCA (
EIOLCA 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 purchas ...
) 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.


Ecologically based LCA

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-based LCA

Exergy of a system is the maximum useful work possible during a process that brings the system into equilibrium with a heat reservoir. 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 The second law of thermodynamics is a physical law based on universal experience concerning heat and Energy transformation, energy interconversions. One simple statement of the law is that heat always moves from hotter objects to colder objects ( ...
, 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 Transport (in British English), or transportation (in American English), is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land (rail and road), water, cable, pipeline, an ...
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

Life cycle energy analysis (LCEA) is an approach in which all
energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...
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. With LCEA, the ''total life cycle energy input'' is established.


Energy production

It is recognized that much energy is lost in the production of energy commodities themselves, such as
nuclear energy Nuclear energy may refer to: *Nuclear power, the use of sustained nuclear fission or nuclear fusion to generate heat and electricity * Nuclear binding energy, the energy needed to fuse or split a nucleus of an atom *Nuclear potential energy ...
,
photovoltaic Photovoltaics (PV) is the conversion of light into electricity using semiconducting materials that exhibit the photovoltaic effect, a phenomenon studied in physics, photochemistry, and electrochemistry. The photovoltaic effect is commercially us ...
electricity or high-quality petroleum products. ''Net energy content'' is the energy content of the product minus energy input used during extraction and
conversion Conversion or convert may refer to: Arts, entertainment, and media * "Conversion" (''Doctor Who'' audio), an episode of the audio drama ''Cyberman'' * "Conversion" (''Stargate Atlantis''), an episode of the television series * "The Conversion" ...
, directly or indirectly. A controversial early result of LCEA claimed that manufacturing
solar cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.
s requires more energy than can be recovered in using the solar cell. Although these results were true when solar cells were first manufactured, their efficiency increased greatly over the years. Currently, energy payback time of photovoltaic solar panels range from a few months to several years. Module recycling could further reduce the energy payback time to around one month. 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.


Energy recovery

If materials are incinerated during the disposal process, the energy released during burning can be harnessed and used for
electricity production Electricity generation is the process of generating electric power from sources of primary energy. For utilities in the electric power industry, it is the stage prior to its delivery (transmission, distribution, etc.) to end users or its storag ...
. This provides a low-impact energy source, especially when compared with
coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...
and natural gas. While incineration produces more
greenhouse gas emissions Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Most is carbon dioxide from burning fossil fuels: coal, oil, and natural gas. The largest emitters include coal in China and lar ...
than
landfill A landfill site, also known as a tip, dump, rubbish dump, garbage dump, or dumping ground, is a site for the disposal of waste materials. Landfill is the oldest and most common form of waste disposal, although the systematic burial of the waste ...
s, the waste plants are well-fitted with regulated pollution control equipment to minimize this negative impact. A 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 Landfill gas is a mix of different gases created by the action of microorganisms within a landfill as they decompose organic waste, including for example, food waste and paper waste. Landfill gas is approximately forty to sixty percent methane, ...
is recovered for electricity production.


Criticism

Energy efficiency Energy efficiency may refer to: * Energy efficiency (physics), the ratio between the useful output and input of an energy conversion process ** Electrical efficiency, useful power output per electrical power consumed ** Mechanical efficiency, a ra ...
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. 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. In recent years, the literature on life cycle assessment of energy technology has begun to reflect the interactions between the current
electrical grid An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids vary in size and can cover whole countries or continents. It consists of:Kaplan, S. M. (2009). Smart Grid. Electrical Power ...
and future energy technology. Some papers have focused on
energy In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...
life cycle,J.M. Pearce
"Optimizing Greenhouse Gas Mitigation Strategies to Suppress Energy Cannibalism"
2nd Climate Change Technology Conference Proceedings, p. 48, 2009
while others have focused on
carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...
(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 arises when using the energy analysis method is that different energy forms—
heat In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is al ...
,
electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...
,
chemical energy Chemical energy is the energy of chemical substances that is released when they undergo a chemical reaction and transform into other substances. Some examples of storage media of chemical energy include batteries, Schmidt-Rohr, K. (2018). "How ...
etc.—have inconsistent functional units, different quality, and different values. This is due to the fact that the
first law of thermodynamics The first law of thermodynamics is a formulation of the law of conservation of energy, adapted for thermodynamic processes. It distinguishes in principle two forms of energy transfer, heat and thermodynamic work for a system of a constant amoun ...
measures the change in internal energy, whereas the second law measures entropy increase. Approaches such as
cost analysis In Production (economics), production, research, retail, and accounting, a cost is the value of money that has been used up to produce something or deliver a service, and hence is not available for use anymore. In business, the cost may be one o ...
or exergy may be used as the metric for LCA, instead of energy.


LCA dataset creation

There are structured systematic datasets of and for LCAs. A 2022 dataset provided standardized calculated detailed environmental impacts of >57,000
food Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inge ...
products in supermarkets, potentially e.g., informing consumers or
policy Policy is a deliberate system of guidelines to guide decisions and achieve rational outcomes. A policy is a statement of intent and is implemented as a procedure or protocol. Policies are generally adopted by a governance body within an organ ...
. There also is at least one
crowdsourced Crowdsourcing involves a large group of dispersed participants contributing or producing goods or services—including ideas, votes, micro-tasks, and finances—for payment or as volunteers. Contemporary crowdsourcing often involves digita ...
database for collecting LCA data for food products. Datasets can also consist of options, activities, or approaches, rather than of products – for example one dataset assesses PET bottle
waste management Waste management or waste disposal includes the processes and actions required to manage waste from its inception to its final disposal. This includes the collection, transport, treatment and disposal of waste, together with monitoring ...
options in Bauru, Brazil. There are also LCA databases about buildings – complex products – which a 2014 study compared.


LCA dataset platforms

There are some initiatives to develop, integrate, populate, standardize, quality control, combine and maintain such datasets or LCAs – for example: * The goal of the LCA Digital Commons Project of the U.S. National Agricultural Library is "to develop a database and tool set intended to provide data for use in LCAs of food, biofuels, and a variety of other bioproducts". * The Global LCA Data Access network (GLAD) by the UN's Life Cycle Initiative is a "platform which allows to search, convert and download datasets from different life cycle assessment dataset providers". * The BONSAI project "aims to build a shared resource where the community can contribute to data generation, validation, and management decisions" for " product footprinting" with its first goal being "to produce an
open data Open data is data that is openly accessible, exploitable, editable and shared by anyone for any purpose. Open data is licensed under an open license. The goals of the open data movement are similar to those of other "open(-source)" movements ...
set and an
open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use the source code, design documents, or content of the product. The open-source model is a decentralized sof ...
toolchain capable of supporting LCA calculations". With product footprints they refer to the goal of "reliable, unbiased
sustainability Specific definitions of sustainability are difficult to agree on and have varied in the literature and over time. The concept of sustainability can be used to guide decisions at the global, national, and individual levels (e.g. sustainable livi ...
information on products".


Dataset optimization

Datasets that are suboptimal in accuracy or have gaps can be, temporarily until the complete data is available or permanently, be patched or optimized by various methods such as mechanisms for "selection of a dataset that represents the missing dataset that leads in most cases to a much better approximation of environmental impacts than a dataset selected by default or by geographical proximity" or
machine learning Machine learning (ML) is a field of inquiry devoted to understanding and building methods that 'learn', that is, methods that leverage data to improve performance on some set of tasks. It is seen as a part of artificial intelligence. Machine ...
.


Integration in systems and systems theory

Life-cycle assessments can be integrated as routine processes of systems, as input for modeled future socio-economic pathways, or, more broadly, into a larger context (such as qualitative scenarios). For example, a study estimated the environmental benefits of microbial protein or harm of beef within a future socio-economic pathway, showing substantial
deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...
reduction (56%) and
climate change mitigation Climate change mitigation is action to limit climate change by reducing Greenhouse gas emissions, emissions of greenhouse gases or Carbon sink, removing those gases from the atmosphere. The recent rise in global average temperature is mostly caus ...
if only of per-capita beef was replaced by microbial protein by 2050. Life-cycle assessments, including as product/technology analyses, can also be integrated in analyses of potentials, barriers and methods to shift or regulate consumption or production. The life-cycle perspective also allows considering losses and lifetimes of rare goods and services in the economy. For example, the usespans of, often scarce, tech-critical metals were found to be short as of 2022. Such data could be combined with conventional life-cycle analyses, e.g., to enable life-cycle material/labor cost analyses and long-term economic viability or
sustainable design Environmentally sustainable design (also called environmentally conscious design, eco-design, etc.) is the philosophy of designing physical objects, the built environment, and services to comply with the principles of ecological sustainability ...
. One study suggests that in LCAs, resource availability is, as of 2013, "evaluated by means of models based on depletion time, surplus energy, etc." Broadly, various types of life-cycle assessments (or commissioning such) could be used in various ways in various types of societal
decision-making In psychology, decision-making (also spelled decision making and decisionmaking) is regarded as the Cognition, cognitive process resulting in the selection of a belief or a course of action among several possible alternative options. It could be ...
, especially because financial markets of the economy typically do not consider life cycle impacts or induced societal problems in the future and present—the "
externalities In economics, an externality or external cost is an indirect cost or benefit to an uninvolved third party that arises as an effect of another party's (or parties') activity. Externalities can be considered as unpriced goods involved in either co ...
" to the contemporary economy.


Critiques

Life cycle assessment is a powerful tool for analyzing commensurable aspects of quantifiable systems. 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 Boundary critique (BC) is the concept in critical systems thinking that, according to Ulrich (2002), states that "both the meaning and the validity of professional proposition In logic and linguistics, a proposition is the meaning of a declarati ...
to
systems thinking Systems thinking is a way of making sense of the complexity of the world by looking at it in terms of wholes and relationships rather than by splitting it down into its parts. It has been used as a way of exploring and developing effective actio ...
. The accuracy and availability of data can also contribute to inaccuracy. For instance, data from generic processes may be based on
average In ordinary language, an average is a single number taken as representative of a list of numbers, usually the sum of the numbers divided by how many numbers are in the list (the arithmetic mean). For example, the average of the numbers 2, 3, 4, 7, ...
s, unrepresentative sampling, or outdated results. This is especially the case for the use and end of life phases in the LCA. 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. An in-depth review of 13 LCA studies of wood and paper products 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 Carbon sequestration is the process of storing carbon in a carbon pool. Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in land ...
and methane generation in landfills and with
carbon accounting Greenhouse gas accounting or Carbon accounting is a framework of methods to measure and track how much greenhouse gas (GHG) an organization emits or takes actions to reduce. Corporations, cities and other groups use these techniques to help li ...
during forest growth and product use. Moreover, the fidelity of LCAs can vary substantially as various data may not be incorporated, especially in early versions: for example, LCAs that do not consider regional emission information can under-estimate the life cycle environmental impact.


See also

*
Agroecology Agroecology (US: a-grō-ē-ˈkä-lə-jē) is an academic discipline that studies ecological processes applied to agricultural production systems. Bringing ecological principles to bear can suggest new management approaches in agroecosystems. The ...
*
Agroecosystem analysis Agroecosystem analysis is a thorough analysis of an agricultural environment which considers aspects from ecology, sociology, economics, and politics with equal weight. There are many aspects to consider; however, it is literally impossible to acco ...
* Anthropogenic metabolism *
Biofuel Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. According to the United States Energy Information Administration (E ...
*
Depreciation In accountancy, depreciation is a term that refers to two aspects of the same concept: first, the actual decrease of fair value of an asset, such as the decrease in value of factory equipment each year as it is used and wear, and second, the a ...
*
Design for the Environment 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 a ...
* *
Ecodesign Ecological design or ecodesign is an approach to designing products and services that gives special consideration to the environmental impacts of a product over its entire lifecycle. Sim Van der Ryn and Stuart Cowan define it as "any form of de ...
*
Ecological footprint The ecological footprint is a method promoted by the Global Footprint Network to measure human demand on natural capital, i.e. the quantity of nature it takes to support people or an economy. It tracks this demand through an ecological accounti ...
*
End-of-life (product) An end-of-life product (EOL product) is a product at the end of the product lifecycle which prevents users from receiving updates, indicating that the product is at the end of its useful life (from the vendor's point of view). At this stage, a v ...
*
ISO 15686 ISO 15686 is the in development ISO standard dealing with service life planning. It is a decision process which addresses the development of the service life of a building component, building or other constructed work like a bridge or tunnel. I ...
* Water footprint


References


Further reading

# Crawford, R.H. (2011) Life Cycle Assessment in the Built Environment, London: Taylor and Francis. # J. Guinée, ed:,
Handbook on Life Cycle Assessment: Operational Guide to the ISO Standards
', Kluwer Academic Publishers, 2002. # Baumann, H. och Tillman, A-M. The hitchhiker's guide to LCA : an orientation in life cycle assessment methodology and application. 2004. # Curran, Mary A. "Environmental Life Cycle Assessment", McGraw-Hill Professional Publishing, 1996, # Ciambrone, D. F. (1997). ''Environmental Life Cycle Analysis''. Boca Raton, FL: CRC Press. . # Horne,Ralph., ''et al.'' "LCA: Principles, Practice and Prospects". CSIRO Publishing,Victoria, Australia, 2009., # Vallero, Daniel A. and Brasier, Chris (2008), "Sustainable Design: The Science of Sustainability and Green Engineering", John Wiley and Sons, Inc., Hoboken, NJ, . 350 pages. # Vigon, B. W. (1994). ''Life Cycle Assessment: Inventory Guidelines and Principles''. Boca Raton, FL: CRC Press. . # Vogtländer,J.G., "A practical guide to LCA for students, designers, and business managers", VSSD, 2010, . # When


External links

*
LCA Example: Light Emitting Diode (LED) from GSA's Sustainable Facilities Tool
{{DEFAULTSORT:Life Cycle Assessment Design for X Environmental impact assessment Industrial ecology