A Beginners Guide to Life Cycle Assessment

Applications, Benefits & Challenges

Author: Damon Waterworth | April 2020

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges

A Beginner’s Guide to Life Cycle Assessment

International supply chains have global environmental implications and the growing emphasis on sustainability has prompted the need for organisations to incorporate life cycle thinking into their decision-making. This approach supports the transition from the linear, take, make, dispose economic model to a sustainable, circular alternative. Life Cycle Assessment (LCA) tools provide an objective method to demonstrate your commitment to sustainability by increasing your awareness of the impacts purchasing decisions and production systems have on the natural environment. LCA goes beyond the traditional focus of legal compliance by encouraging proactive management of environmental aspects and impacts, thus supporting Environmental Management System goals. This white paper describes the key features of an LCA and how it can be used to better understand the environmental implications of the products you manufacture, purchase or sell.

Section 1: Background What is Life Cycle Assessment?

LCA is a well-established environmental accounting tool used to identify, characterise and assess environmental impacts across a product’s entire life cycle from raw material extraction (‘cradle’) to final disposal (‘grave’). By taking a systems perspective, LCA tools help businesses understand the flows of matter and energy involved in the material, processing, distribution and packaging elements of their products.

1. Goal & scope definition

LCA follows the internationally recognised framework developed by the International Organization for Standardization (ISO) (Figure 1). This framework defines four key stages: goal and 2. Inventory analysis scope definition, inventory analysis, impact assessment and interpretation. The process is iterative, with many of the stages Interpretation 4. revisited to accommodate changes in study goals and data 3. Impact assessment availability.

Figure 1. LCA Framework (Source: ISO 14040)

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges

LCA Applications & Benefits

Organisations can use LCA to gain insights that allow them to plan, develop, procure, market and improve the environmental footprint of their products (Figure 2). Being aware of and understanding the implications of key decisions can encourage companies to develop and implement innovative solutions. For this reason, the benefits of commissioning an LCA are many, including improved management of supply chain risks and cost savings, both of which provide you with a competitive advantage (Figure 3).

Strategic Planning Increase environmental awareness

Green Procurement Justify decisions to stakeholders

Ecolabels & Declarations Manage supply chain risks

Benefits Marketing Conserve resources & save Applications money

Product Development or Selection Increase customer loyalty

Process Improvement Achieve competitive advantage

Figure 2. Common Applications Figure 3. Potential benefits

LCA & Environmental Management Systems

The ISO 14001:2015 Environmental Management Systems (EMS) standard An LCA is considered requires organisations to adopt a life cycle approach in order to continually the most effective way improve their environmental performance. Specifically, the standard requires to demonstrate organisations to control or influence the way products are designed, conformance with key manufactured, distributed, consumed and disposed of, by adopting a life cycle ISO requirements perspective that prevents environmental impacts from being unintentionally shifted elsewhere within the life cycle.

LCA supports your EMS goals by highlighting significant Key ISO requirements environmental aspects and impacts that facilitate proactive supply- • Life cycle approach chain management and drive product improvements. For this • reason, LCA is often the best way to demonstrate conformance with Continual improvement the life cycle approach and other key ISO requirements. • Supply chain management

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges

Section 2: Methodology Goal & Scope Definition

Study Aims

Before commissioning an LCA, you should have a clear purpose in mind. For example, you may wish to use LCA to: • Determine a product’s significant environmental impacts • Evaluate how a product compares to a competitor’s product, or • Understand which changes will result in the greatest overall environmental improvements

LCA Types

LCAs are data intensive, time consuming activities. Therefore, it is advised that you align your study aim with the appropriate assessment type (Table 1). A full, cradle-to-grave LCA may not be necessary under some circumstances. Streamlined assessments can be useful for those who intend to make product comparisons where there are processes or stages used in both systems. In this situation elements within the LCA are identified that can be omitted or ignored without impairing the overall result. Similarly, streamlined LCA can be useful for assessing environmental impacts of particular stakeholder concern. A carbon footprint is an example of such an assessment.

Table 1. Aligning your study aim with the appropriate LCA type Type Description Purpose

Streamlined LCA Identifies environmental hotspots related to Develops understanding of the environmental a specific environmental impact category performance of new and existing products including (e.g. carbon footprint) or life cycle stage (e.g. those currently under development. manufacturing) Environmental Investigates supply chain impacts and Profile identifies environmental hotspots across a product’s life cycle. Benchmarking Compares the environmental ‘preferability’ Compares and evaluates the environmental impacts LCA of two developed products with the same of different product systems allowing you to select function. products based on their environmental performance.

Environmental Identifies the preferable product Supports your R&D and ISO Management System Scenarios development options by comparing impacts goals by identifying the most environmentally Modelling given a range of inputs (e.g. choice of friendly product development options. materials, ingredients / substances, locations, energy sources).

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges

Functions & Functional Units

All LCA studies require a clearly defined functional approach. According to the ISO standard, the function describes the main performance characteristics of a product system while the functional unit provides a quantified description, indicating how much of this function is to be included in the study.

• An example function could be “a hydrating skin cream” • The related functional unit could be “one 150ml liquid volume container of skin cream”

System Boundaries

The system boundary defines which processes should be included in (or excluded from) the system of interest and will help you determine the data required to fulfil your study objectives. Please see the example system boundary for a cosmetic product in Figure 4. Note that transport steps are not shown but are included.

Virgin material Granulate Injection extraction processing moulding

Ingredient Water Mixing and Distribution Use Packaging acquisition purification filling (Store) phase disposal

Water phase

mixing Packaging

Landfill Oil phase mixing

Recycling / Incineration System Boundary

Figure 4. System boundary for a skin moisturiser

Dealing with multifunctional systems

The ‘allocation problem’ arises when a product system is multifunctional or closely interlinked with other systems which produce multiple outputs. One option is to allocate or partition the environmental burdens according to their mass or energy requirements or economic value. The schematic below illustrates partitioning for a multifunctional skin moisturiser:

Skin Moisturiser Resources Product (Mass: 99%, Energy: 75%, Value: 30%) Materials and Manufacturing ingredients Energy from incineration (Mass: 1%, Energy: 25%, Value: 70%)

Waste packaging to landfill 5

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges

The second option is to expand the system boundary as illustrated in Figure 5. This is preferable because expansion captures additional functions related to the co-products and wastes and the resulting changes in the product system, as opposed to cutting them off by allocation.

Virgin material Granulate Injection extraction processing moulding

Ingredient Water Mixing and Distribution Use Packaging acquisition purification filling (Store) phase disposal

Water phase mixing Packaging

Landfill Oil phase mixing

Recycling

Incineration (Waste to energy plant)

Avoided production processes

Virgin plastic Energy production New System Boundary

Figure 5. Expanded system boundary

Decide your modelling approach

You will need to decide on one of two modelling approaches, these are:

• Attributional modelling (aLCA): depicts the system as it can be observed or measured, linking the input and output flows of all processes of a system as they occur. Modelling processes along an existing supply-chain is an example of this approach. • Consequential modelling (cLCA): considers the consequences of the background system based on decisions made in the foreground. In other words, it describes how environmental impacts might change in response to, for example, market mediated effects on demand for a product or coproduct.

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges Life Cycle Inventory Analysis

Life cycle inventory (LCI) is a collection of data inputs and outputs on the basis of reference flows (relates to the functional unit). Primary data sourced directly by the producer is preferred while secondary data should be used to fill the gaps based on logical assumptions. Examples of primary and secondary sources is shown in Figure 6.

Primary Secondary

Bill of Materials (BOM) Databases

Bill of substances (BOS) Publications

Experiment results Equipment specs

Meter readings Surveys

Safety Data Sheet (SDS)

Figure 6. Potential data sources

Often the use of proxies or assumptions is unavoidable. In these instances, you should consider the most likely source, region or outcome, or best proxy for a missing material, ingredient or process as shown below.

Unknown Assume most No primary Assume origin of common energy use national ingredient source input data energy mix

Once any data gaps have been filled and the inventory completed, a model of the product system can be developed. At this point it is recommended that you review your project scope to ensure they still align. Often, unforeseen data restrictions or quality issues mean that the system boundary or project aim are reworked several times before being finalised. Remember, LCA is an iterative process!

Don’t take shortcuts! Garbage In = An LCA is only as good as the data used. You should prioritise data quality so that you end Garbage Out up with a representative model and results that add business value.

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges Life Cycle Impact Assessment

The life cycle impact assessment (LCIA) stage assesses the potential human and ecological effects of product systems based on the inputs and outputs specified in the LCI. This is achieved through a four-step process: classification, characterisation, normalisation (optional) and weighting (optional).

Classification & Characterisation

Classification is the process of organising inventory data according to their effects on the environment while characterisation is the quantified contribution of each substance to each of the selected environmental impact categories. Characterisation can occur at mid-point and end-point level. Both provide useful information to decision makers and are therefore considered complementary.

Figure 7. Schematic steps from inventory to category endpoints (Source: ILCD Handbook)

Midpoint analysis provides singular environmental impact scores at the point of comparison (e.g. radiative forcing for climate change), while endpoint analysis uses aggregated midpoint results to determine the impacts related to three areas of protection: human health, biodiversity, and resource scarcity. This process from inventory classification to end-point characterisation is mapped in Figure 7.

Be aware that end-point There is less uncertainty when modelling only at the point of comparison (i.e. the modelling results in midpoint level). However, it is often easier to communicate end point results to greater uncertainty non-technical audiences.

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges

Be aware that some impact categories are more mature than others! For Consider the technical example, global warming potential/climate change is a well-defined, abilities of your audience quantitative midpoint category while land use change is not so well defined when choosing your as quantitative estimation is difficult to achieve. characterisation method

Normalisation & Weighting (Optional)

Normalisation – how much is this? Expresses potential impacts relative to a reference situation, e.g. per capita per year, per £ value.

Weighting – how important is this? Ranking, grouping or assigning importance to impact categories based on value choices (e.g. stakeholder concerns – subjective).

Note that the subjective nature of normalisation and weighting steps mean that this should not be included in LCA studies intended to be released to the public.

Results Interpretation

The results interpretation stage involves result presentation, determination of data sensitivity, and sometimes critical review. Here you may also consider significant sources of uncertainty.

Sources of Uncertainty in LCA Results

Uncertainties in LCA results can be grouped into 3 types: 1. Data uncertainty • Reliability of the data used to build your product inventory (e.g. source) • Intrinsic data uncertainty (e.g. measurement errors, equipment precision) • Representativeness of data used (e.g. spatial, temporal, geographical) • Assumptions and choices made to model the system (e.g. national energy mix, use of cut off criteria) 2. Methodological uncertainty • choice of allocation methods (e.g. allocation by mass) • consequential LCA is associated with market-based uncertainties 3. Model uncertainty • impact assessment factors within a given impact assessment methodology

Note: every decision you make contributes to the overall uncertainty associated with the modelled system.

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges

Communicating Uncertainty

Probabilistic statements ensure that uncertainty surrounding indicator results are communicated clearly.

Example indicator result

Product A contributes 17.5 kg CO2e / FU while product B contributes 30 kg CO2e / FU. Based on this information, product A appears to have a lower carbon footprint. However, how confident are you with these results?

Example probabilistic statement

Product A contributes 17.5 ± 2.5 kg CO2e / FU (range 15 – 20 kg CO2e) while product B contributes 30 ± 20 kg CO2e /

FU (range 10 – 50 kg CO2e). These probabilistic statements allow you to appreciate the degree of uncertainty in the results as reflected by the potential range of values. In this case, while product A has a lower mean greenhouse gas contribution, under some circumstances this is not the case.

Most likely value

Range of Uncertainty can also be communicated visually values using histograms and bar charts as shown below. Less Less uncertainty uncertainty These graphs show the results of statistical calculations such as Monte Carlo simulations, providing us with a probabilistic model.

More uncertainty

Presenting Results

The way you present your results will depend on: • The study deliverables • The study aims and application • The intended target audience

Note that some audiences will be more familiar than others with LCA – some people will only want to know the key outcomes of the study put across in simple language. Results should not be communicated in a way that is misleading!

A Beginner’s guide to Life Cycle Assessment: Applications, Benefits & Challenges

Risk of Misinterpretation

The comprehensive, technical methodology means that LCA’s are robust product evaluation tools. However, this also make the results challenging to communicate. Due to the complexity, LCA studies can be used by organisations to promote the perception that their products are environmentally friendly, even when they are not. For this reason, you need to ensure that you don’t unintentionally mislead your audience. This often occurs when results are interpreted beyond what is supported by the evidence which can lead to accusations of greenwashing – something you really ought to avoid!

Section 3: Conclusions

Summary & Recommendations

• Start simple. You can always build in complexities later. • Use generic data in your initial LCA model and use this to determine your priorities for data collection. You will want to avoid collecting the most detailed and accurate data on the least contributing processes of the life cycle model. • Have your intended audience in mind from the outset. Use this to guide your choice of data presentation. • Never adjust the scope of your study to make your product appear more sustainable. • Take the time to improve your data collection processes and maintain a log of all data sources as this will positively affect the value of your LCA results and save time later. • Use LCI databases such as GaBi or Ecoinvent to fill in data gaps or model generic processes (e.g. energy grid).