Life cycle analysis

Phases of a life cycle analysis

A life cycle analysis (also known as environmental impact , life cycle assessment or English Life Cycle Assessment or LCA ) is a systematic analysis of the environmental impacts of products throughout the entire life cycle ( " from cradle to grave ", "from the cradle to the grave"). If the processing is only analyzed up to a certain point in time, for example only from the extraction of raw materials to processing in a factory, it is no longer a life cycle analysis because then the entire life cycle of a product is not considered.

The life cycle analysis includes all environmental impacts during the production, the usage phase and the disposal of the product as well as the associated upstream and downstream processes (e.g. production of raw materials and supplies). The environmental impact includes all environmentally relevant removals from the environment (e.g. ores, crude oil ) and emissions into the environment (e.g. waste , carbon dioxide emissions ). The term “balance sheet” is used in the life cycle assessment in the sense of a comparison. It is not to be confused with the balance sheet within accounting.

Distinction

A general distinction is made between:

a life cycle assessment that takes into account the environmental aspect of an individual product,
a comparative life cycle assessment that compares several products, and
a holistic accounting that includes economic, technical and / or social aspects.

In addition to the life cycle assessment (product-related life cycle assessment, product life cycle assessment), a material flow analysis can also be used to determine other material and energy balances : operational environmental assessments and process life cycle assessments . These differ from the life cycle assessment in that they refer to a period (often called the balance year) and that they are not based on the causation principle (which material and energy flows has the product caused over its entire life cycle?). The corporate environmental balance sheet can often be found, for example, in environmental and sustainability reports from companies.

With the ISO 14040 standard , the term life cycle assessment can only be used for product-related life cycle assessments. However, this standard defines “Product” as “any goods or services” and expressly includes things such as transport , the repair of a vehicle or the provision of information in the context of knowledge transfer. The methodology of a life cycle assessment can therefore also be used for the (ecological) investigation of procedures and processes and is also used for this.

In the business environment, the life cycle assessment can be counted among the ecologically-oriented planning instruments of controlling . However, it is more important in (environmental) politics and legislation.

purpose

The common goal of the various corporate life cycle assessment methods is to systematically check operations for possible ecological risks and weak points and to identify potential for optimization. The starting point for this is the consideration that the annual input (in kilograms and kilowatt hours) that goes into the company must correspond in terms of quantity to the output and the changes in inventory. It is particularly important for this equation that input, output and changes in inventory are fully measured (i.e. including, for example, the incoming rainwater, evaporation, leaks in the interim storage facility, etc.). Based on this inventory analysis, the respective input and output substances are analyzed with regard to their effects on the environment, and finally the total number of substances and their effects are assessed. The creation of life cycle assessments is also referred to as material flow analysis.

construction

A complete life cycle assessment according to the ISO 14040 standard comprises the following elements:

Definition of goal and scope of investigation,
Life cycle inventory ,
Impact assessment and
Evaluation.

On June 30, 2006 the second edition of ISO 14040 and the new ISO 14044 were published. The latter summarizes the previous individual standards ISO 14041 to 14043. Together with ISO 14040, ISO 14044 represents the standard for an ISO-compliant life cycle assessment. The aim of this revision of the series of standards was to simplify the series through summary and thereby improve readability. The content remained largely unchanged.

When defining the objective and the scope of the investigation , it is first determined what the life cycle assessment should be used for. This definition influences all further decisions and is therefore a very important step in a life cycle assessment, which is often neglected. Then the benefits and functions of the product are defined and the basic life cycle of a product starting with the extraction of raw materials and ending with the corresponding disposal. In addition, interrelationships with other substances are taken into account, assumptions and restrictions are defined and the preliminary limits of the investigation are determined (definition of cut-off criteria). Another important point is the definition of the so-called functional unit. This is understood to be the product-specific variable to which the environmental impacts are subsequently related (e.g. a refrigerator, 1000 kWh of electrical energy, etc.)

In the subsequent inventory analysis, quantitative statements are made about the product life cycle that has just been recorded. For this purpose, the resource consumption (input information, inputs) is compared with the benefit (functional unit) or the correlated emissions (output variables, outputs). The inventory inventory is in itself a purely descriptive (descriptive) model without any evaluation. However, every inventory analysis contains implicit evaluations that result from the previously defined system boundaries, cut-off criteria and restrictions.

The impact assessment then divides the results of the inventory inventory into different impact categories according to scientifically based qualitative aspects and shows, for example, the relevance of different emissions for the greenhouse effect or for the formation of the ozone hole . The result of the impact assessment is a number (usually 5–10) of quantitative environmental impacts that a product causes (e.g. contribution to the greenhouse effect, acid rain, ozone hole, etc.). This step includes (mostly implicitly) an assessment, on the one hand by the selection of the impact categories per se and on the other hand by the selection of the emissions that are assigned to a certain impact category or not. The modeling of the contribution of an emission to an impact category is also linked to value judgments. In the course of the impact assessment, the so-called normalization can optionally take place, in which the environmental impacts are scaled to a so-called population equivalent (i.e. environmental impacts based on 1, 100 or 1000 inhabitants). This last step simplifies the presentation of results.

In the evaluation , parameters that are important for the result (e.g. individual life cycle stages or impact categories) are identified. This is followed by a consistency, completeness and sensitivity analysis. Conclusions and recommendations are developed from the results and a report is written. The evaluation is the most subjective part of an evaluation, as the individual environmental impacts are weighted here. So z. For example, the question of whether the global warming potential is more important than the acidification potential can only be decided at the political and social level.

In order to clarify whether a life cycle assessment fulfills the requirements for the methodology, data quality, evaluation and reporting and whether it complies with the principles of the standards, a critical review can be carried out by an independent expert. Such a critical examination can contribute to the credibility of the life cycle assessment, e.g. B. by involving interested parties. In the case of a comparative life cycle assessment that is intended for publication, such a critical review is prescribed according to ISO 14040 , whereby an examination by an examination committee with at least three members (review panel) is required.

From these aspects one can conclude that a life cycle assessment has great potential as a decision-making aid for producers and consumers. It is a meaningful and often decisive instrument for assessing the environmental compatibility of products, increasingly during or before product development. However, it must also be said that the results of a life cycle assessment study, which was created with a specific purpose and thus also with a specific focus and the resulting modeling, cannot simply be transferred to another question. Examines z. If, for example, a life cycle assessment is whether amorphous or crystalline photovoltaic cells are ecologically more sensible for a specific application, the result cannot be generalized or transferred to another situation. One problem with this is that the cells have different degrees of efficiency and therefore a different area is required for the same power output. This makes it crucial how the cells are installed, as the supporting structure makes a (relevant) contribution to the results of the life cycle assessment.

software

In most cases, life cycle assessments are created with the help of software. The EU Joint Research Center has compiled a list.

Aggregation and evaluation procedures

In DIN EN ISO 14040: 2006 it is written: “There is not just one method for creating life cycle assessments. Organizations can - depending on the intended application and the needs of the organization - implement life cycle assessments [...] flexibly ”. The best known methods are:

ABC analysis
CML method
Greenhouse gas balance (also called CO ₂ footprint or CO ₂ balance )

Eco-Indicator 99 : expresses the overall environmental relevance of a product or system in a single number, unit of points [Pt]. Impact categories are normalized and weighted differently.

Environmental Priority System (damage cost approach)

Critical volumes

cumulative energy expenditure

MIPS

Sustainable Process Index (SPI)

UBA impact indicators

Environmental pollution points , see method of ecological scarcity

Verbal evaluation

Avoidance cost approach

Virtual water

The following table systematizes the best-known evaluation methods for creating a life cycle assessment with regard to the point in time when they are used in life cycle assessment, the monetary or non-monetary consideration, the dimension, the evaluation parameter and the result of the method.

method	application	Consideration	dimension	System boundary	Assessment size	Result
ABC analysis	Life cycle inventory	non-monetary	multidimensional	cradle-to-grave	Material and energy flows	multi-dimensional profile for each material and energy flow
CML method	Impact analysis	non-monetary	multidimensional	cradle-to-grave	Material and energy flows in 14 impact categories	specific contributions per impact category result in impact profile
CO ₂ balance	Impact potential	non-monetary	one-dimensional	cradle-to-gate	direct and indirect greenhouse gas emissions	Key figure: CO ₂ -eq emissions
Eco indicator 99	Impact analysis	non-monetary	one-dimensionally aggregated	cradle-to-grave	Material and energy flows in 9 impact categories	Eco-Indicator-Points in various damage categories
Environmental Priority System (damage cost approach)	Impact analysis	monetary	one-dimensionally aggregated	gate-to-grave	abiotic resources, health or environmental damage to health, production of ecosystems or environmental economic. Damage to biodiversity or loss of species, aesthetics (cultural and recreational value)	monetary quantity: financially valued damage
Critical volumes	Life cycle inventory	non-monetary	multidimensional	cradle-to-grave	Air and water pollution, amount of waste, energy consumption	4 key figures: critical air volume, critical water volume, waste volume, energy equivalent value
Cumulative energy expenditure	Life cycle inventory	non-monetary	one-dimensional	cradle-to-gate	Energy intensity	Key figure: energy consumption
MIPS	Life cycle inventory	non-monetary	one-dimensionally aggregated	cradle-to-grave	Material flows (input of the inventory analysis), service units	Key figure: material input
Method of ecological scarcity	Life cycle inventory	non-monetary	one-dimensionally aggregated	gate-to-gate	Material and energy flows differentiated into input and output	Key figure: environmental pollution points
UBA impact indicators	Impact analysis	non-monetary	multidimensional	cradle-to-gate	Material and energy flows in different impact categories	multi-dimensional key figure profile
Verbal evaluation	in addition to the inventory analysis / impact analysis	non-monetary	multidimensional	cradle-to-grave	Complete recording theoretically possible	verbal description
Avoidance cost approach	Life cycle inventory	monetary	one-dimensionally aggregated	cradle-to-gate	Defense, compensation and repair activities	monetary size: avoidance costs
Virtual water	Life cycle inventory	non-monetary	one-dimensional	cradle-to-gate	virtual water content	Key figure: water requirement of a product / service

The dimension reflects the number of indicators included in the assessment. Procedures that refer to only one key figure in the result (e.g. CO ₂ balance) are referred to as "one-dimensional". On the other hand, procedures in which several indicators form the result are characterized as "multidimensional".

The consideration provides information about the monetary or non-monetary representation of the results of an evaluation process.

The quantifiability is an expression for the scaling of the results of the respective procedure. Here, ordinal (qualitative evaluation methods) or metrically (quantitative evaluation methods) scaled results are the distinguishing feature. Of the methods presented here, only the ABC analysis and the verbal evaluation are qualitative, all others are quantitative evaluation methods .

In the course of the selection of an evaluation method in the context of a life cycle assessment, it is considered useful to consider a method evaluation. Criteria for the assessment include the traceability, practicability, completeness and transferability of the method. Further criteria can be the separation of the factual and value levels and the plurality of values.

criticism

In a study in which emissions from agriculture, in particular from animal husbandry, were examined, the authors have shown that the life cycle analysis only takes direct greenhouse gas emissions into account. In the case of agricultural products in particular, land use also plays a major role. The authors added the missed carbon sink potential to the LCA, i.e. unrealized CO ₂ storage potential , on the grounds that agricultural areas bind far less CO ₂ from the atmosphere than natural vegetation. They came to the conclusion that the indirect emissions from land use were on average just as large as all other emissions from animal husbandry and thus significantly higher than indicated by the LCA.

literature

Stefan Bieletzke: Simulation and life cycle assessment: Development of a model for the analysis of economic and ecological effects . Deutscher Universitäts-Verlag , Münster 1998, ISBN 978-3-8244-6965-9 ( online ).
Manfred Finke: The life cycle assessment - a component of the sustainability assessment. in Naturwissenschaftliche Rundschau 61 (1), pp. 21-26, Stuttgart 2008, ISSN 0028-1050 .
Stefan Schaltegger, Ruedi Kubat: The concise dictionary of life cycle assessment. Terms and definitions. 3rd edition, Wirtschaftwissenschaftzentrum, Basel 1995 (first edition 1994), ISBN 3-909162-06-1 (= WWZ study no. 45).
Walter Klöpffer, Birgit Grahl: Life cycle assessment (LCA): A guide for training and work. Wiley-VCH, Weinheim 2009, ISBN 978-3-527-32043-1 .
Henrikke Baumann, Anne-Marie Tillman: The Hitch Hiker's Guide to Lca: An Orientation in Life Cycle Assessment Methodology and Applications. Professional pub. Service 2004, ISBN 978-91-44-02364-9 .

Web links

Commons : Life Cycle Assessment - collection of images, videos and audio files

research

European Platform on Life Cycle Assessment . Offers (s):
- Directory of the European Commission on life cycle assessment services, databases, software and their providers
- Life cycle assessment database of the European Commission - EU-wide life cycle assessment data (free of charge)
Swiss discussion forum on life cycle assessments with an ongoing series of events since 1996

Individual evidence

↑ DIN EN ISO 14040: 2006 environmental management - life cycle assessment - principles and framework conditions. P. 33.

↑ Software list ( Memento of the original from January 9, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . @1@ 2

↑ DIN EN ISO 14040: 2006 environmental management - life cycle assessment - principles and framework conditions. P. 18.

^ Edeltraud Günther: Ecology-oriented management. Lucius & Lucius, Stuttgart 2008, ISBN 978-3-8282-0415-7 , pp. 292-332.

↑ Beate Stahl: Method comparison and method development for solving the evaluation problem in product-related life cycle assessments Dissertation, University of Bremen 1998, Department of Production Technology, p. 60.

↑ ^a ^b ^c Heinz-Georg Baum, Adolf G. Coenenberg , Edeltraud Günther: Company environmental economics in cases - environmental management and ecology-oriented instruments. Volume II, R. Oldenbourg Verlag, Munich, Vienna 2000, ISBN 3-486-24687-9 , pp. 160-161.

↑ Beate Stahl: Method comparison and method development to solve the evaluation problem in product-related life cycle assessments Dissertation, University of Bremen 1998, Department of Production Technology, p. 61.

↑ Stefan Schaltegger, Andreas Sturm: Ecology-oriented decisions in companies - ecological accounting instead of life cycle assessment: necessity, criteria, concepts. 3rd edition (Internet edition), Basel 2000, p. 128.

^ Kurt Schmidinger, Elke Stehfest: Including CO2 implications of land occupation in LCAs — method and example for livestock products . In: The International Journal of Life Cycle Assessment . tape 17 , no. 8 , September 1, 2012, ISSN 1614-7502 , p. 962–972 , doi : 10.1007 / s11367-012-0434-7 ( springer.com [accessed July 2, 2019]).

↑ Fritz Habekuß: Greenhouse effect : climate calculation speaks for tofu instead of beef steak . In: The time . July 5, 2012, ISSN 0044-2070 ( zeit.de [accessed July 2, 2019]).

[1] DIN EN ISO 14040: 2006 environmental management - life cycle assessment - principles and framework conditions. P. 33.