From "Life Cycle Assesment - Theory and Practice" (H2018) Flashcards
LCA characteristics can be grouped into four headlines. Which?
(1) takes a life cycle perspective,
(2) covers a broad range of environmental issues, (3) is quantitative,
(4) is based on science.
Why are LCA considering multiple environmental issues?
To avoid burden-shifting between impacts.
Describe the strengths of LCA
The LCA is comprehensive in terms of its life cycle perspective and coverage of environmental issues. It allows comparison of environmental impacts of product systems that are made up of hundreds of processes, accounting for thousands of resource uses and emissions that are taking place in different places at different times.
What are the limitations about an LCA being comprehensive?
The modelling of the product systems requires simplifications and generalisations and this result in the LCA calculating potential (not acutal) environmental impacts.
What can an LCA conducted on two product systems tell you and what can it not tell you?
It can tell which product system is better for the environment.
It cannot tell if “better” is good enough. It is wrong to conclude that a product is environmentally sustainable in absolute terms.
In 1997 the first version of ISO 14040 standard was published. What was the attempt by this publishing?
Harmonize the framework and principles of LCA and to increase transparency and comparability of LCA studies.
From an government perspective, what can the application of LCA support?
Policy formulation, policy implementation and regulation imposed by policies, and can be used to perform evaluation of policies.
The application of LCA in enterprises can be classified into five main purposes. Which?
(i) decision support in product and process development.
(ii) marketing purposes (e.g. Eco-labelling).
(iii) development and selection of indicators used in monitoring of environmental performance of products or plants.
(iv) selection of suppliers or subcontractors.
(v) strategic planning.
What is LCA often used for at the product level?
Product development and for identifying environmental hotspots of a product or process either within the organization or in its supply chain.
How are consumers exposed to LCA results?
Through ecolabels or other consumer information from producers.
Through the media reporting academic findings.
The LCA framework operates with four separate phases. Which?
1) Goal and scope definition
2) Inventory analysis
3) Impact assessment
4) Interpretation
Which questions should be answered in the goal definition?
Why is this study performed?
Which question(s) is it intended to answer and for whom is it performed?
The goal definition sets the context of the LCA study and is the basis of the scope definition where the assessment is framed and outlined in accordance with the goal definition
What should be included in the scope definition?
- Defining the functional unit and reference flow
- Scoping the product system, deciding which activities and processes belong to the life cycle of the product that is studied.
- Selecting the assessment parameters, i.e. the impacts that shall be assessed in the study.
- Selecting the geographical and temporal boundaries and settings of the study and the level of technology that is relevant for the processes in the product system.
- Deciding the relevant perspective to apply in the study: should it be a consequential study assessing the impacts that can be expected as a consequence of choosing one alternative over another, or should it be an attributional study assessing the impacts that are associated with the studied activity?
- Identifying the need to perform critical review, in particular if the study is a comparative assertion intended to be disclosed to the public.
What is done in an inventory analysis?
It collects information about the physical flows for the product system.
The physical flows are:
Input of resources, materials, semi-products and products and the output of emissions, waste and valuable products
What is the outcome of the inventory analysis?
The life cycle inventory, a list of quantified physical elementary flows for the product system that is associated with the provision of the service or function described by the functional unit.
What is done in life cycle impact assessment (LCIA)?
The impact assessment translates the physical flows and interventions of the product system into impacts on the environment using knowledge and models from environmental science.
Which 5 elements does the impact assessment consists of? Give a short explantion for all 5 elements.
1) Selection of impact categories representative of the assessment parameters that were chosen as part of the scope definition.
2) Classification of elementary flows from the inventory by assigning them to impact categories.
3) Characterisation using environmental models for the impact category to quantify the ability of each of the assigned elementary flows to impact the indicator of the category.
4) Normalisation is used to inform about the relative magnitude of each of the characterised scores for the different impact categories by expressing them relative to a common set of reference impacts—one reference impact per impact category.
5) Grouping or weighting supports comparison across the impact categories by grouping and possibly ranking them according to their perceived severity, or by weighting them using weighting factors that for each impact category gives a quantitative expression of how severe it is relative to the other impact categories.
What does the interpretation consider?
The interpretation considers both results of the inventory analysis and the impact assessment elements characterisation and, possibly, normalisation and weighting. The interpretation must be done with the goal and scope definition in mind.
What is a sensitivity analysis and uncertainty analysis used for in the interpretation phase?
To guide the development of conclusions from the results, to appraise the robustness of the conclusions, and to identify the focus points for further work in order to further strengthen the conclusions.
Mention the six aspects of goal definition
- Intended applications of the results,
- Limitations due to methodological choices
- Decision context and reasons for carrying out the study,
- Target audience
- Comparative studies to be disclosed to the public
- Commissioner of the study and other influential actors.
All LCAs involve studying one or more product systems and this can be used in several applications. Mention some of these applications.
- Comparing environmental impacts of specific goods or services.
- Identifying the parts of a product system that contribute most to its environmental impact (i.e. “hot spot identification”, focusing in product development).
- Evaluating improvement potentials from changes in product designs (analysis and ‘what-if’ scenarios in eco-design).
- Documenting the environmental performance of products (e.g. in marketing using environmental product declarations or other types of product environmental footprints).
- Developing criteria for an eco-label.
- Developing policies that consider environmental aspects.
Mention the three different types of decision contexts:
Situation A (Micro-level decision support) Situation B (Meso/macro-level decision support) Situation C (Accounting)
Explain decision context: Situation A
The study results are intended used to support a decision, but the small scale of the studied product system means that regardless the decision made, it will not cause structural changes in the systems that the studied product system interacts with.
Explain decision context: Situation B
The study results are intended used to support a decision, and the scale of the studied product system is such that the decisions that are made are expected to cause structural changes in one or more processes of the systems that the studied product system interacts with.