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State of LCA in Denmark 2003 4 Practical advice
4.1 Choices in LCA - basic considerationsFundamentally the choices to be made during the preparation of an LCA will deal with what this LCA is to be used for. However, it is not enough to determine the goal and the application. One also has to consider the complexity of the situation and the consequences of the decisions to be made. In reality also the experience available and the willingness to invest are relevant issues. The goal and the application It is always essential that the decision-maker has clearly defined to himself what the goal of the LCA to be undertaken is. And the goal should be defined as precisely as possible. Ideally the task is to answer the following questions:
Integrated in these questions may be more sub-questions which are having an impact on the form of LCA that shall be undertaken and how. The following questions should be regarded as examples of such sub-questions:
It is outside the framework of a guideline like this to list all the questions, which could be relevant to different applications. Therefore, this issue will here be summarized as follows: After definition of the study goal made by the decision-maker, the LCA-practician - i.e. the person actually undertaking the study - is to return with proposals for functional unit, system boundaries, allocation principles and other basic choices of methodology. These proposal then have to be compared with the goal to assess, whether the goal will be accomplished. Experience shows that in this process it is very important to clarify whether LCA actually is the right tool for the problem that is addressed. One may e.g. face problems which should be solved with a chemical assessment rather than an LCA. The complexity of the situation
Complex situations may be difficult to assess, if a quantification is not carried out. In such cases it is in reality given that a reliable LCA must be carried out as a detailed LCA. Is the situation more simple, a simplified LCA and partly qualitative assessments may be completely adequate. The LCA levels detailed and simplified are defined in section 2.3 and further discussed in section 4.2. It is noted that for multi-product systems and in situations with recycling it will be necessary with special considerations on system expansion and allocation (i.e. how are the common loads allocated to the different products - e.g. how is electricity consumption allocated in the slaughterhouse on skin, meat and waste). Such questions are discussed in section 4.2 in the subsection on system boundaries and allocation. The consequence of the work undertaken It should be considered as common sense to assume that the higher the importance an LCA is ascribed, the more thorough the work must be done. This applies to LCA at society level as well as at company level and other applications. Thoroughness in particular is a matter of being able to document and justify the choices made in the LCA and the conclusions made. The elements that must be documented concern the LCA methodology, system boundaries, the data utilised, sensitivity analysis, uncertainty assessments and similar matters. Marketing is an application requiring careful consideration. A technology cannot in itself be clean or environmentally friendly. On the other hand a technology can be cleaner or more environmentally friendly or less polluting than other technologies. It is obvious to use LCA for comparative marketing. Also here one must be careful. Normally it is only possible to state that assessed by a specific methodology and specific criteria a product may be environmentally better than another. Reference is made to the Consumer Ombudsman's guideline in environmental marketing [Forbrugerombudsmanden, 2004]. Experience available The experience that is available may therefore be a parameter that should be taken into account, when the approach is decided. In reality experience may be bought as e.g. consultancy assistance. Willingness to invest It is obvious that the ability and the will to invest in LCA may be so insignificant that the LCA that can be carried out will not be able to solve the problem in question. In this case, it has no meaning to initiate an LCA. The ability and will to invest in LCA may be related to, whether we are dealing with a single LCA or a series for which large-scale advantages may apply. Large-scale advantages may be relevant to companies producing many products designed highly identical, like e.g. different models. 4.2 Choices in LCA - methodology elements and their useIn this section is presented a number of key elements in LCA, and it is discussed when it is relevant to use these elements and to what extent the decision-maker has a choice. LCA level
These levels are described in section 2.3. In table 4.1 is stated the applications for which the individual levels may be appropriate. As indicated in the table many applications may be carried out at several LCA levels. Somewhat simplified and straightforward it may be said that:
It is emphasized that the choice of LCA level typically has determining influence on other choices of methodology. System boundaries and allocation In the guideline on Geographical, technological and temporal delimitation in LCA [Weidema 2004] a procedure to delimit the relevant processes that shall be included in the assessment, from non-relevant processes has, however, been presented. Thereby the traditional rules for delimitation are in principle superfluous. The guideline is also giving advice on allocation and recommends that allocation is avoided and replaced by system expansion, which means that the product system is expanded until all relevant processes are included. This recommendation is also given in ISO standard 14041 [DS/EN ISO 14041, 1998]. Even if system expansion in the future shall be regarded as the rule, allocation may not always be avoided. It is possible that in some cases system expansion may lead to an unreasonably large product system, which may be difficult and time-consuming to deal with. Practical reasons may thus still justify allocation and the use of traditional rules for system delimitation. It is emphasized that the recommended methodology for allocation according to the ISO standard is the principle known as allocation by the physical relationships [DS/EN ISO 14041, 1998]. It is the responsibility of the decision-maker to decide whether the principles and rules presented by the LCA practician to determine system boundaries and to allocate are appropriate. In accordance with the recommendations in section 4.1 (the complexity of the situation) considerations on allocation will normally only be relevant in relation to detailed LCA. The need for and collection of data The need for data collection is determined on the basis of whether the data available are satisfying for the assignment to be undertaken. That data are not satisfying means, that they are not adequately representative of the process that has to be described. Thereby the uncertainty of the conclusions can be unacceptably high. One cannot claim that data collection implies any methodology choice by the decision-maker, but the decision-maker naturally has a choice as to when the data quality - and thereby the uncertainty of the result - should be regarded as acceptable. Data collection should typically be carried out as iterative processes, in the way that one based on screening determines the processes that contribute the most to the total environmental impacts. Thereafter the data collection is focussed on these processes. Trend analysis/technological forecasting Impact categories The decision-maker, however, also has a responsibility to ensure that all significant environmental impacts are covered by the LCA in question. According to ISO standard 14042 [DS/EN ISO 14042, 2000] the impacts considered should together give a adequate picture of the total environmental load from the product or the system. This means that in case important impacts exists - e.g. noise or land use - which are not covered by the EDIP methodology, then these impacts should also be considered in the LCA in question, at least qualitatively. Land use may thus be relevant to consider for products which contains significant quantities of materials originating from forestry or agriculture. It is emphasized that by the interpretation of results it may be allowed not to include a few impact categories, assuming that the results of these impact categories are deemed unreliable due to uncertain or missing data. It is, however, important that this is clearly stated. Spatial characterisation Normalisation and weighting It is emphasized that the decision-maker is free to develop and choose his own weighting factors. It is e.g. obvious that a county or region may recommend that the local companies are using special weighting factors for waste directed to landfilling or for eutrophication and other impact categories for which the county/region as environmental authority based on local conditions deems that special consideration is necessary. Lack of appropriate areas for landfills may e.g. be an argument for recommending specially high weighting factors for waste to be landfilled. Companies producing to a specific market may e.g. choose to assign high weight to the priorities among the customers in this market. Sensitivity analysis and uncertainty assessment It can be expected that sensitivity analysis and uncertainty assessment will be integrated in the LCA computer programmes - at least in GaBi - which will be approved by the Danish LCA Center within the coming years (see section 2.4). It should therefore be possible and relatively simple to undertake sensitivity analysis and uncertainty assessment in detailed LCA. Also related to life-cycle thinking and simplified LCA uncertainties should naturally be considered. However, no methodologies for doing this has so far been developed, and sensitivity analysis and uncertainty assessment in this context will to a significant extent have to be characterised as estimates. Quality control/critical review It is the choice of the decision-maker to determine, whether a critical review should be carried out and in what way. The Danish EPA has issued a manual on critical review [Caspersen & Wenzel 2002]. As stated in this manual one may distinguish between:
The type of critical review to be used in an LCA will depend on the application and the consequences of this LCA. To use a panel of stakeholders is relevant to LCAs, which compare different products or services with each other and is published. In table 4.1 is assessed, when it otherwise will be relevant to use independent external persons for critical review. When an LCA is being planned, it is important to allocate financial resources for critical review and decide, how this review should be undertaken. For LCAs that are published and could be of interest in the public debate, it should be assumed, that the selection of persons for the task may influence the general accept of the result. ISO standards Generally can be assumed that detailed LCA following the EDIP methodology will fulfil the ISO standards, while simplified LCA and life-cycle thinking will not fulfil the standards. In the cases, in which the decision-maker in his report chooses to state that the LCA fulfils the ISO standards, this statement should naturally be checked by the critical review. Documentation and reporting Documentation and reporting is in particular relevant to LCAs that will be published and used externally. In this context it is a must that the choices made in the LCA and the conclusions made can be documented and justified. The elements that shall be documented concern the LCA methodology, system boundaries, data utilised, other preconditions, sensitivity and uncertainty assessments, interpretation and similar matters. Only LCAs that are documented can expect to be respected. Documentation and reporting is, however, certainly also relevant to LCAs, which are only going to be used internally. In this case the need for documentation is linked to the need of being able to analyse the background for conclusions obtained and furthermore to be able to control, adjust and improve the LCA at a later stage. A general requirement to documentation is that it must be open and transparent. This may however raise conflicts with respect to confidential information. An acceptable solution of this problem is normally that the persons responsible for the critical review, will also have access to the confidential information and thereby can confirm that this information is used in an acceptable and responsible way. ISO Standard 14040 [DS/EN ISO 14040, 1997] also contains requirements on documentation and reporting. Table 4.1
may be relevant to all fields of application and that the choice of whether they should be applied, therefore, depends more on the actual task than on the field of application. Reference is made to section 4.2. Related to table 4.1 please note the following comments: General knowledge development by companies addresses the need of being prepared, e.g. for sudden demands of documented information on environmental issues from key customers. General knowledge development is, however, also important to companies that generally are integrating environmental issues in their planning. Even if general knowledge development may be based on simplified LCA, detailed LCA will typically be more appropriate. Strategic environmental assessment deals with the issue of assessing the company's choice of materials and products in the light of rather long-term trends in the market, e.g. supply reliability, productivity improvements, legislation initiatives and environmental trends in general. This is typically an internal activity in companies. Concerning marketing and environmental product declarations, spatial characterisation has for ethical reasons (reference is made to section 3.4) not been listed as a relevant option. As to ecolabels, the ecolabel criteria are often based on detailed LCA of generalized products, and these LCAs are normally subject to external hearing among professional and industrial bodies, which in this context should be assumed to correspond to external critical review. Both for social action plans and for environmentally-economic analyses - especially cost-benefit analyses - it can be relevant with a detailed assessment of the environmental impacts. Reliable assessments of this type must necessarily consider the local conditions and thus imply spatial characterisation. Table 4.1 Central elements in LCA and when to use them
X: Relevant; (X): Partly relevant 4.3 Start with the simple and easyAn important rule that cannot be repeated too often says: "Start with the simple and easy" The meaning is that it is common sense to start the LCA work as simple and easy as possible and expand it when the need for extra and more detailed information is recognised. Start with life-cycle thinking and simplified LCA and expand it to detailed LCA only when it is deemed necessary. Start with available data from literature and databases, and do not start collecting your own data until it is deemed necessary. And - perhaps the most important message - be critical and honest with respect to what the results can be used for.
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