Production or consumption processes can be seen as a transformation of inputs into outputs. Some of these flows may have a market value, therefore they have a price and can be accounted in monetary units. Some others, for example, might only be accounted in mass units, or in energy units or even in some other metrics, such as hours,items and so forth. Therefore, a framework that uses many metrics is necessary for describing the complexity of reality.
Secondly, there are unquestionable laws that rule our world, such as the laws of Thermodynamics. Production or consumption processes also obey to these laws. In practice, this means that for any input there must always be outputs that obey these laws.
Given these preconditions, the paper introduces a multi-layer supply and use framework, where each layer is balanced and accounted in a single metric. Then an input-output model is built upon this multi-layer framework. The model adopts the Stone's method, which is more known as the by-product technology assumption. Furthermore, endogenous matrices of technical coefficients are presented. This means that technical coefficients are not predetermined and kept fixed when running a simulation. Rather, they are endogenous variables that change according to the implemented analysis. Finally, the model makes use of linear programming techniques instead of implementing the Leontief inverse.
Complementing the textbook, Environmental Assessment of Products (series), this workbook introduces practical execution of LCA. The case-studies are constructed to optimise the learning process. They demonstrate the methods and common mistakes experienced in real-life assessments. The reader is guided in a critical review of the studies, increasing his understanding of good and bad practice in LCA. The new knowledge can then be applied in the reader's own LCA study, using the comprehensive data supplied.
This work provides an unambiguous conceptual framework for inclusion of nutrition in Life Cycle Assessments (LCAs) of food that enables the distinction between two different roles of nutrition, namely serving as the basis of food comparisons via the functional unit and as an impact pathway that links food ingestion with human health effects.
We compare how nutritional aspects have been considered in the functional unit of published LCAs of food with the procedural requirements for ensuring comparability of the functional units. We consider the relevance of nutrient profiling models for assessing food- and diet-related health damages and benefits in the context of LCAs of food. We finally recommend a method that will enable a systematic, comparative, and holistic assessment of the marginal health effect of food products on human health.
Satiety is proposed as a central attribute for comparisons of food products, while weighted measures of nutrient content are suggested to be largely misplaced as part of the functional unit. In contrast, nutritional measures have a large role to play in assessing the human health impacts of the marginal ingestion of specific food products. Such measures should enable a direct quantification of human health effect and benefits and should take advantage of robust epidemiological evidence.
Nutritional measures enter into both the functional unit in the form of satiety measures and into the calculation of impacts in the form of the marginal influence of the specific food item on the human health impact of the overall diet. To enhance the differentiation of health impacts at the level of individual food items, it is recommended to combine the nutrient balance indicator with the DALY Nutritional Index (DANI) in each specific dietary context.
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Technological change is key to understand the explanatory variables behind environmental impacts in the context of the STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology) model. An adequate representation and analysis of the significance of the technology variable (T) in the STIRPAT model becomes crucial, even more if one aims to better understand underlying processes such as the (environmental) rebound effect (E)RE. A critical review of the application of the STIRPAT model has been conducted to understand the diversity and value of the variables, scopes, assumptions, statistical approaches, and the environmental impacts commonly studied. The findings highlight that, despite the multiple applications and the high potential of the STIRPAT model, inconclusive results and/or knowledge gaps remain, notably (1) a geographical imbalance in the scope of studies, (2) the almost exclusive focus on carbon emissions, (3) a lack of agreement on the choice of data, additional explanatory variables, and regression models, (4) a lack of consensus on how to approximate T, and (5) a lack of explicit analyses of the (E)RE. Our findings are useful to both policymakers and academics for method design, further research, and policy evaluation.
Interest from the research and policy community in the circular economy (CE) is growing. This research describes how the potential for a circular economy in open economies can be estimated by using different assessment methods. Methods and indicators have been selected that have a relevance for one or more of the public policy objectives for circular economy: Openness Index, economic structure, Balassa Index, value chain analysis, substitution potential of Sustainable Materials Management (SMM) strategies, waste treatment scenarios based on physical and hybrid Input-Output (IO) analysis. These methods differ in scope and degrees of complexity and are used at different assessment levels. The potential for a circular economy in this paper is assessed by evaluating the contribution to the public policy objectives for CE: resource efficiency, reduction of dependency on materials, competitiveness, creation of domestic jobs, reduced Greenhouse Gas (GHG) emissions. Results obtained by these methods are shown for Belgium and, in some cases, compared to the results of other countries to illustrate the differences between economies. CE activities (in response to public policy objectives) will enhance the ongoing trend of reducing the share of primary sectors in economies. The openness of an economy is expressed as the ratio of sum of import and export and Gross Domestic Product (GDP). Imported products add to the potential of domestic closed-loop circular initiatives like re-use, repair, remanufacture, recycling, but this will require knowledge about composition and spare part availability. Exported products are no longer available for these domestic CE initiatives, reducing the domestic potential for CE and the domestic export activity is vulnerable to CE activities abroad. Especially the increasing geographical distance in trade complicates the practical and legal barriers to close the loop. In open economies, both global and domestic substitution effects due to new circular economy policy initiatives are important to consider.
A conceptually complete taxonomy is proposed at three levels of the impact pathway: Elementary flows, midpoint impacts, and endpoint impacts. The completeness is ensured conceptually by including unspecified residuals and by the use of fully quantifiable indicators that can be traced from source to sink, so that completeness can be verified by input-output balances and against measured totals. Each category in the taxonomy has a definition and at the lowest level also a unit of measurement. Examples of category definitions and units are illustrated in an impact pathway model with starting point in the midpoint impact category “Undernutrition”. This model also demonstrates the role of the taxonomy in the development of characterisation factors
This paper seeks to provide a detailed procedural description for performing a consistency check for LCA as required by the ISO 14044 standard.
Consistency is defined as freedom from logical contradictions. The requirements of ISO 14044 are reviewed, and detailed guidance is provided for these and other related consistency issues.
The procedural guidance reflects the iterative nature of the phases of LCA. Some inconsistencies can be of a more fundamental nature that does not allow a single consistent solution. Instead, more than one separately consistent solution can then be found and applied as separate “scenarios” presented to the decision maker with appropriate explanation of the fundamental differences of the scenarios, and their respective strengths and weaknesses for the decision context.
Revisiting and correcting inconsistencies can avoid most consistency problems. However, lack of resources may prohibit such adjustments, and the inconsistencies and their implications for the conclusions may then simply be stated and the conclusions modified accordingly.
This work provides a conceptual framework to distinguish between two different roles of nutrition in Life Cycle Assessment of foods, namely on the one hand in the functional unit that forms the basis of comparisons of foods, and on the other hand in the calculations of health impacts from ingestion of food products. Satiety is proposed as a central attribute for comparisons of food products, while weighted measures nutrient content are suggested to be largely misplaced as part of the functional unit. In contrast, nutritional measures have a large role to play in assessing the human health impacts of the marginal ingestion of specific food products for the more than half of the global population that lives on an unbalanced diet.
This short report summarises the current knowledge on the interests of companies and policymakers to link the UN Sustainability Goals (the SDGs) to business needs and explores the interest in using Life Cycle Assessment (LCA) as a tool to support the use of SDGs.
There has been a flurry of proposals and reports on how to bridge the gap between the "official" SDG’s and what companies can contribute. Some reports have focused on the importance and business benefits of business involvement, while others have focused on identifying the extent of current business interest and efforts. Many organisations and joint initiatives have written whitepapers that address the links between the SDG’s and existing reporting frameworks, and how to select the most relevant SDG’s. We review a few of the most interesting (in our view) in the following.
We conclude in Section 7 that there are many on-going parallel initiatives that addresses business stakeholder issues as well as gaps and needs, but none of these addresses the specific potential contributions and solutions that can be offered by linking the SDGs to life cycle impact pathway frameworks.
In Section 8 we shortly introduce our new project “Linking the UN Sustainable Development Goals to life cycle impact pathway frameworks” that aims to overcome the identified gaps by developing a clear linkage between the visionary process that led to the creation of the SDG’s and all the science-based knowledge, data and methodology in the Life Cycle Sustainability Assessment area.
This document summarizes the state of the discussions in the ISO TC207/SC5/TG1 drafting groups before the TG1 and SC5 meeting in Berlin where further progress on these issues were halted. It is provided here for historical documentation only.
The motivation for raising the discussion was that in practice, the ISO 14040 and 14044 are used for different goals and scopes (as outlined in Annex A.1 of ISO 14040), including some that were not originally foreseen when drafting the standard text. This has led to two different approaches to LCA (as mentioned in Annex A.2 of ISO 14040), which especially diverge in their interpretation of the requirements of ISO 14044. That the same requirement can be interpreted in two ways, and that these interpretations are not always clearly linked to the goal and scope of the assessments, has lead to the proliferation of guidelines that seek to promote their own interpretation of ISO 14044, with consequent unfortunate controversies that hamper the intended application of the standards.
