SSBTi-LCA Course-2
The ISO LCA Standard – Goal and Scope
Reference: nanozeo.WebLCA.net trainings, Ecoinvent website, ISO 14040/44/14064/14067 standards, EU-Product Environmental Footprint (PEF), CDP/SBTi requirements, Dr. CP Tung and Dr. Chunpo Hung's SSBTi/TFF/SFIT trainings, CLCD/CPCD/ELCD databases, and many thanks and special honor to: H. Scott Matthews, Chris T. Hendrickson, and Deanna Matthews, Life Cycle Assessment: Quantitative Approaches for Decisions that Matter, 2014. SSBTi LCA
ESG and Footprints Based on Life Cycle Assessment: One for All Approaches to SBTi
Life Cycle Assessment (LCA) provides a structured framework for evaluating environmental impacts across a product's entire lifecycle. The ISO LCA Standard establishes globally accepted guidelines for conducting rigorous LCA studies, ensuring consistency and credibility in environmental assessments.
This presentation explores the critical components of the ISO LCA Standard, with particular focus on the Goal and Scope phase. We'll examine the study design parameters that form the foundation of any LCA study and provide practical guidance for implementing them effectively.
RW
by Raymond Wang
Last edited 1 day ago
Presentation Overview
1
ISO LCA Framework
Understanding the four major phases of the ISO LCA Standard and how they interact to create a comprehensive assessment framework.
2
Study Design Parameters
Exploring the critical parameters that define an LCA study, including goal, functional unit, system boundaries, and more.
3
Practical Applications
Examining real-world examples and best practices for implementing the ISO LCA Standard in various contexts.
4
Challenges and Considerations
Identifying common pitfalls and providing strategies for addressing them in LCA studies.
The ISO LCA Standard
ISO 14040:2006
Provides the principles and framework of LCA, written primarily for a managerial audience. It outlines the overall structure and requirements for conducting LCA studies.
ISO 14044:2006
Offers detailed requirements and guidelines for practitioners. This document contains specific technical instructions for implementing each phase of an LCA study.
Historical Context
The first version of the ISO LCA Standard was published in 1997, with the current version updated in 2006. Many foundational LCA studies predated these formal standards.
Four Phases of the ISO LCA Framework
Goal and Scope Definition
Establishes the study's purpose, boundaries, and parameters
1
Inventory Analysis
Collects and quantifies inputs and outputs across the life cycle
2
Impact Assessment
Evaluates potential environmental impacts of inventory results
3
Interpretation
Analyzes results, draws conclusions, and makes recommendations
4
The ISO framework emphasizes that these phases are iterative rather than strictly sequential. Findings in one phase often lead to revisions in others, creating a dynamic process that improves as the study progresses.
Study Design Parameters (SDPs)
Goal
Clearly states the intended application, reasons for the study, target audience, and whether results will be used for public comparative assertions.
Product System
Defines the collection of processes that provide the function being studied, including their relationships and flows.
System Boundary
Specifies which processes are included in the study and which are excluded, often visualized in a diagram.
Functional Unit
Quantitatively defines the function of the product system, providing a reference for normalizing inputs and outputs.
More Study Design Parameters
Inventory Inputs and Outputs
Specifies which environmental flows will be tracked and measured throughout the product system, such as energy use, emissions, or resource consumption.
LCIA Methods
Identifies the impact assessment methodologies that will be used to translate inventory data into potential environmental impacts, such as global warming potential or resource depletion.
Additional Parameters
Other required elements include data quality requirements, allocation procedures, assumptions, limitations, and critical review requirements if applicable.
The Goal Statement
1
Intended Application
Specifies how the results will be used, such as for product improvement, marketing, policy development, or strategic planning.
2
Reasons for the Study
Explains the motivation behind conducting the LCA, which might include identifying environmental hotspots, comparing alternatives, or supporting claims.
3
Target Audience
Identifies who will use the results, such as internal decision-makers, customers, policymakers, or the general public.
4
Comparative Assertions
States whether the results will be used to make public claims that one product is environmentally superior to another, which triggers additional requirements.
Example Goal Statement
"The findings of the study are intended to be used as a basis for educated external communication and marketing aimed at the American Christmas tree consumer." "The goal of this LCA is to understand the environmental impacts of both the most common artificial Christmas tree and the most common natural Christmas tree, and to analyze how their environmental impacts compare." "This comparative study is expected to be released to the public by the ACTA to refute myths and misconceptions about the relative difference in environmental impact by real and artificial trees."
This example from a real Christmas tree LCA study clearly addresses all four required elements: the intended application (external marketing), reasons (refute misconceptions), audience (American tree consumers), and public comparative assertions (explicitly stated).
The goal statement uses the keyword "goal" and provides sufficient detail for readers to understand the study's purpose without ambiguity.
Common Goal Statement Mistakes
1
Incomplete Information
"This study seeks to find the energy use of a power plant" only addresses one element (reason) while omitting application, audience, and comparative assertions. It also never uses the word "goal."
2
Vague Purpose
"The goal of this study is to produce an LCA for internal purposes" lacks specificity about how the results will be used and why the study is being conducted.
3
Implied Bias
Goal statements that suggest predetermined conclusions or favor certain alternatives can undermine credibility and raise concerns about objectivity.
4
Misalignment with Scope
When the goal statement promises analysis that the scope parameters cannot deliver, the study risks failing to meet its stated objectives.
Understanding Product Systems
A product system is the collection of processes and flows related to a product's life cycle that deliver one or more functions. It encompasses all activities required to create, use, and dispose of a product.
Processes
Activities that transform inputs to outputs, such as manufacturing, transportation, or waste treatment. These are represented as boxes in system diagrams.
Flows
Materials or energy moving between processes, including product flows (connecting different systems) and elementary flows (exchanges with the environment).
Unit Processes
The smallest elements considered in the analysis for which input and output data are quantified, forming the building blocks of the system.
System Boundary
The system boundary defines which subset of processes and flows from the overall product system are included in the study. This critical parameter determines the scope of analysis and directly impacts results.
Visual Representation
A diagram is crucial for helping audiences understand the complexity of the product system and its defined boundary. The diagram should clearly mark which processes are included and excluded.
Justification
System boundaries must be justified with explanations of why certain processes were included or excluded, which helps audiences understand the study's limitations and assumptions.
Consistency
For comparative studies, system boundaries must be consistent across alternatives to ensure fair comparison. Differences in boundaries must be explicitly noted and justified.
Process Flow Diagrams
Components
Boxes represent processes, arrows represent flows, and dashed lines often indicate system boundaries. These diagrams visualize how materials and energy move through the product system.
Levels of Detail
High-level diagrams may show aggregated life cycle stages (raw materials, production, use, etc.), while more detailed diagrams break these down into specific unit processes.
Unit Processes
The smallest elements in the analysis for which input and output data are quantified. Complex products may involve thousands of unit processes, requiring strategic aggregation.
Direct vs. Indirect Effects
Direct Effects
Impacts that occur directly as a result of activities in the process being studied. For example, emissions from burning fuel in a manufacturing facility or water used directly in a production process.
Indirect Effects
Impacts that occur as a result of activities, but outside the immediate process. These include upstream impacts from producing raw materials or energy, and downstream impacts from product use or disposal.
A comprehensive LCA captures both direct and indirect effects, though practical limitations often require simplifications and focusing on the most significant processes and flows.
Elementary Flows
Input Elementary Flows
Material or energy entering the system that has been drawn from the environment without previous human transformation. Examples include raw materials like iron ore, crude oil, or solar energy.
Output Elementary Flows
Material or energy leaving the system that is released into the environment without subsequent human transformation. Examples include emissions to air, water, or soil.
Relationship to System Boundary
Elementary flows cross the system boundary, connecting the product system to the environment. They are the inputs and outputs of interest that often motivate the study.
System Boundary Example
"For the artificial tree the system boundary includes: (1) cradle-to-gate material environmental impacts; (2) the production of the artificial tree with tree stand in China; (3) transportation of the tree and stand to a US retailer, and subsequently a customer's home; and (4) disposal of the tree and all packaging."
This example from the Christmas tree LCA clearly defines what processes are included within the system boundary. It covers the entire life cycle from raw material extraction ("cradle") to disposal, including manufacturing, transportation, and end-of-life management.
A well-defined system boundary like this helps readers understand exactly what the study does and doesn't include, providing context for interpreting the results.
Understanding Function
1
Definition
The function represents the performance characteristics of the product system—what it does. This description clarifies the purpose of the product or service being studied.
2
Examples
A power plant's function is generating electricity. A Christmas tree's function is providing holiday joy. A hand dryer's function is drying hands. A light bulb's function is providing light.
3
Importance
Clearly describing the function helps avoid confusion about the product system's purpose and ensures that comparative studies are evaluating functionally equivalent alternatives.
Functional Unit
Definition
A quantitatively defined measure relating the function to the inputs and outputs being studied. It provides a reference to which all results are normalized.
Characteristics
Must be quantitative, include units, and bridge the function with inputs and outputs. Should relate to the function rather than the physical product whenever possible.
Importance
Enables meaningful comparisons between alternatives by ensuring they provide equivalent utility. Results are expressed per functional unit (e.g., kg CO₂ per kWh).
Functional Unit Examples
Product System | Function | Functional Unit | Example LCI Results | |
Power Plant | Generating electricity | 1 kWh of electricity generated | kg CO₂ per kWh | |
Christmas Tree | Providing holiday joy | 1 undecorated tree over 1 holiday season | MJ energy per undecorated tree per holiday season | |
Hand Dryer | Drying hands | 1 pair of hands dried in a restroom facility | MJ energy per pair of hands dried in restroom | |
Light Bulb | Providing light | 100 lumens light for 1 hour (100 lumen-hrs) | g Mercury per 100 lumen-hrs |
These examples demonstrate how functional units bridge the function of a product system with the inventory results, providing a basis for meaningful quantification and comparison.
Common Functional Unit Problems
Non-Quantitative Definition
Stating "the functional unit is generating electricity" fails because it doesn't quantify the function or include units. A proper functional unit would be "1 kWh of electricity generated."
Confusing with Inputs/Outputs
Using "tons of CO₂" as a functional unit incorrectly focuses on an output rather than the function. This creates circular reasoning when normalizing results (kg CO₂ per kg CO₂).
Non-Equivalent Comparisons
Comparing "1 gallon of ethanol" to "1 gallon of gasoline" is misleading because they have different energy contents. A better functional unit would be energy content or distance driven.
Inventory Inputs and Outputs
Specification
The study must explicitly state which inputs and/or outputs will be tracked. This could focus only on inputs (e.g., energy use), only outputs (e.g., carbon emissions), or both.
Scope Limitation
Not every possible input and output needs to be considered. The selection should align with the study goals and be justified based on relevance and data availability.
Transparency
Clearly stating which flows are tracked helps readers understand why certain system boundaries were chosen and provides context for interpreting results.
Impact Assessment Methods
1
Purpose
Impact assessment translates inventory results (e.g., emissions) into potential environmental impacts (e.g., climate change). This helps interpret the significance of inventory data.
2
Required Specification
The study must explicitly list the impact categories selected and the methodology to be used. This helps readers understand how inventory data will be interpreted.
3
Examples
Common impact assessment methods include Global Warming Potential (GWP) for climate impacts and Cumulative Energy Demand (CED) for energy use. These methods use characterization factors to convert inventory data to impact indicators.
Comparative Assertions
Definition
A comparative assertion is an environmental claim regarding the superiority or equivalence of one product versus a competing product that performs the same function.
Additional Requirements
When making comparative assertions, the study must be a full LCA (not just LCI), include impact assessment, and undergo additional sensitivity analysis to test the robustness of conclusions.
Peer Review
ISO requires that comparative assertions intended for public disclosure must undergo critical review by a panel of independent experts to verify ISO compliance and methodological soundness.
Equivalent Comparison
Products being compared must use the same functional unit, methodological considerations, and system boundaries to ensure a fair and meaningful comparison.
Peer Review Process
1
Review Panel Formation
A team of independent experts (typically three) is assembled with relevant expertise in LCA methodology and the product category being studied.
2
Study Evaluation
The panel reviews the study methodology, data quality, calculations, results, and conclusions to assess ISO compliance and scientific validity.
3
Report Generation
The panel produces a detailed report documenting their findings, including any concerns, recommendations, or required revisions to ensure compliance.
4
Study Finalization
Study authors address panel feedback, making necessary revisions before finalizing the study for public release with the review statement included.
Practical Challenges in LCA Studies
System Complexity
Real-world product systems can involve thousands of processes. For example, an automobile has roughly 30,000 components, making complete analysis practically impossible.
Data Availability
Obtaining high-quality data for all processes can be challenging, often requiring proxy data, estimates, or scope adjustments to accommodate data limitations.
Resource Constraints
Comprehensive LCAs can be time-consuming and expensive. The automobile industry LCA mentioned in the chapter took two years, involved more than 10 person-years of effort, and cost millions of dollars.
Strategies for Managing Complexity
1
Strategic Simplification
Focus on the most significant processes and flows based on preliminary assessments or existing knowledge. This helps allocate resources to areas with the greatest impact.
2
Representative Sampling
Select representative facilities or processes when studying complex systems with many similar components, as was done in the automobile industry LCA.
3
Iterative Refinement
Begin with a simplified model and progressively add detail to areas identified as significant through sensitivity analysis and preliminary results.
4
Clear Documentation
Transparently document all simplifications, assumptions, and limitations to help readers understand the study's scope and interpret results appropriately.
Life Cycle Inventory vs. Life Cycle Assessment
Life Cycle Inventory (LCI)
An accounting-like exercise that quantifies total inputs and outputs without considering impacts. Results might include total energy use or emissions but don't translate these into environmental impact categories.
While valuable for understanding resource flows, an LCI alone cannot support comparative assertions under ISO requirements.
Life Cycle Assessment (LCA)
Includes inventory analysis plus impact assessment, which translates inventory results into potential environmental impacts like climate change or resource depletion.
A full LCA provides more meaningful interpretation of environmental significance and is required for comparative assertions under ISO.
The ISO Standard allows for studies that stop at the inventory phase (LCI), but these should be clearly identified as such and recognized as having different capabilities than a full LCA.
Key Takeaways
1
Framework Understanding
The ISO LCA Standard provides a structured, iterative framework with four phases: goal and scope definition, inventory analysis, impact assessment, and interpretation.
2
Study Design Parameters
Carefully defined SDPs—including goal, product system, system boundary, functional unit, inventory inputs/outputs, and impact assessment methods—form the foundation of a rigorous LCA study.
3
Functional Unit Importance
The functional unit must quantitatively bridge the function with inputs and outputs, enabling meaningful comparisons and properly normalized results.
4
Comparative Assertions
Public comparative assertions require additional rigor, including peer review by independent experts to verify ISO compliance and methodological soundness.