This guide provides a high level overview of the steps you should take to arrive at a product or service carbon footprint. It also shows you how you can communicate this effectively to stakeholders. It is an essential supporting document for anyone creating their first inventory or hoping to improve their processes.
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This guide is designed for companies and organizations of all sizes in all economic sectors and all countries seeking a better understanding of the greenhouse gas (GHG) inventory of the products they design, manufacture, sell, purchase, or use.
If you are brand new to carbon accounting, we recommend reading the Comprehensive Guide to Measuring Business GHG Emissions first.
Welcome to this guide, it will aim to help you measure the carbon equivalent emissions attributable to a product if you’ve never conducted one before. A PCF will be an estimation of the total emissions of greenhouse gases (GHG) associated with that specific product throughout its life cycle.
We will consider all life cycle stages and associated emissions, providing a comprehensive environmental impact assessment in a PCF based on the Life Cycle Assessment (LCA) approach and will be expressed in carbon dioxide equivalents (CO₂ₑ).
Alternatively referred to as product GHG inventories, it is performed according to a consistent framework that provides a quantitative performance metric to set targets for improvement, track progress, and communicate successes to internal and external stakeholders. External stakeholders include customers, investors, shareholders, and others. With increasing interest in measured and reported progress in company emissions reductions, identifying reduction opportunities, setting goals, and reporting on progress to stakeholders may help differentiate a company in an increasingly environmentally conscious marketplace. (Greenhouse Gas Protocol Product Standard Page 10)
Product life cycle GHG accounting is a subset of life cycle assessment, LCA became internationally standardized by the International Organization for Standardization (ISO) with the publication of the 14040 series of life cycle assessment standards.
Throughout this guide, we will be showcasing a real-world example of a Product Carbon Footprint from one of our clients. This example showcases the PCF of Café Binocle, a coffee roaster based in Montreal, Canada.
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Climate Change Management
Performance Tracking
Supplier and Customer Stewardship
Product Differentiation
Source: GHGP Product Standard Chapter 2
Ensure that the product GHG inventory accounting methodologies and reports serve the decision-making needs of the intended user. Present information in the report in a way that is readily understandable by the intended users.
Ensure that the inventory report covers all product life cycle GHG emissions and removals within the specified boundaries; disclose and justify any significant GHG emissions and removals that have been excluded.
Choose methodologies, data, and assumptions that allow for meaningful comparisons of a GHG inventory over time.
Ensure that reported GHG emissions and removals are not systematically greater than or less than actual emissions and removals and that uncertainties are reduced as far as practicable. Achieve sufficient accuracy to enable intended users to make decisions with reasonable assurance as to the reliability of the reported information.
Address and document all relevant issues factually and coherently, based on a clear audit trail. Disclose any relevant assumptions and make appropriate references to the methodologies and data sources used in the inventory report. Clearly explain any estimates and avoid bias so that the report faithfully represents what it purports to represent.
While the methodologies outlined in this guide provide a robust framework for calculating your Product Carbon Footprint, leveraging specialized software can significantly streamline the process and enhance accuracy. Breeze, the platform behind this guide, offers a user-friendly suite of tools designed to simplify carbon accounting.
With Breeze, you can efficiently gather data, document your methodologies, calculate emissions using integrated emission factors, and generate detailed reports – all within a user-friendly interface.
By automating complex calculations and providing a centralized platform for data management, Breeze empowers you to effectively measure, analyze, and ultimately reduce the environmental impact of your products.
You may have or might come across new vocabulary, here’s a list of ten terms to be familiar with:
Description: The amount of product on which the results of the study are based.
Example: The reference flow could be 1 kilogram of roasted coffee beans.
Description: The service a product provides. When the function is known (i.e., for final products and some intermediate products), the unit of analysis is the functional unit.
Example: The function of coffee is to provide a beverage that delivers caffeine and flavor.
Description: The performance characteristics and services delivered by the product being studied. A defined functional unit typically includes the function (service) a product fulfills, the duration or service life (amount of time needed to fulfill the function), and the expected quality level.
Example: The functional unit could be "providing 1 cup of brewed coffee with 100 mg of caffeine content."
Description: Assigning the environmental impacts of a product across its life cycle stages. Common methods include mass, energy, and economic allocation.
Example: Imagine a coffee farm that produces both coffee beans and cascara, a tea made from the dried coffee cherry fruit. To understand the environmental impact of coffee beans, you need to attribute the resources used and emissions generated during the farming process. This might involve analyzing the specific inputs and outputs for each product or using allocation methods based on factors like the relative yield or economic value of the coffee beans compared to the cascara.
Description: The process of assigning environmental impacts, such as greenhouse gas (GHG) emissions, resource use, or waste generation, to specific activities, products, or entities based on their contribution to those impacts.
Example: Assigning the energy used in roasting specifically to the production of roasted coffee beans.
Description: Refers to the specific processes, stages, and interactions that are included in the assessment of a product or system's environmental impacts.
Example: For coffee, the system boundary might include coffee bean cultivation and harvesting, roasting, packaging, and distribution.
Description: Refers to the full lifecycle of a product, from the extraction of raw materials ("cradle") through its manufacturing, distribution, use, and ultimately, its disposal ("grave").
Example: The lifecycle of coffee from coffee bean cultivation, roasting, and brewing, to the disposal of the coffee grounds and packaging.
Description: Extends the traditional "cradle to grave" approach by promoting a circular economy, where products are designed with their entire lifecycle in mind, ensuring that materials can be fully reclaimed or repurposed at the end of their useful life.
Example: Designing coffee packaging to be fully compostable or recyclable, and using coffee grounds as fertilizer or bioenergy.
Description: Partial life cycle of a product, encompassing the stages from the extraction of raw materials (the "cradle") up to the point where the product leaves the manufacturing facility (the "gate").
Example: For coffee, the cradle-to-gate assessment might cover the stages from coffee bean cultivation to the packaged roasted beans ready for distribution.
Description: Examines the inputs, outputs, and environmental impacts associated with specific production processes, from the point when materials enter the facility ("gate") to when the finished product exits the facility ("gate").
Example: Evaluating the energy used and waste produced in the factory during the roasting and packaging of coffee beans.
A PCF includes emissions from raw material extraction and processing, manufacturing, distribution, use, and end-of-life management:
Therefore, to calculate a PCF, companies typically follow a standardized methodology such as the Greenhouse Gas Protocol Product Standard. We begin with collecting data on energy consumption, transportation, waste generation, and other relevant factors. Emissions are then estimated using emission factors specific to each activity and location. The final result is expressed in carbon dioxide equivalents “(CO₂ₑ)”.
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For physical products, a comprehensive Life Cycle Assessment (LCA) is conducted to encompass the entire product life cycle and quantify GHG emissions based on inputs and outputs, energy consumption, transportation, materials, and waste generation at each stage. The outcome is the Product Carbon Footprint (PCF).
In contrast, for intangible services, the focus is on defining the scope and boundaries of the service system, collecting data on energy consumption, transportation, and other relevant parameters, and applying emission factors to estimate GHG emissions generated during the provision of the service. Emissions are allocated based on relevant criteria. The outcome is the Service Carbon Footprint (SCF).
Here's a streamlined overview of calculating a PCF to guide you through the essential steps. Adhering to these steps will help ensure that your PCF calculation is both accurate and compliant with global standards, providing a reliable basis for enhancing your environmental strategies.
Product carbon footprint calculations must use a nationally or internationally recognized methodology. This guide is based on ISO 14040, the internationally recognized LCA standard used for the product carbon footprint calculation, and Greenhouse Gas Protocol Product standard. Using both as a reference will provide a good starting point if your product will be marketed only in a local/national market. Consider adding a table explaining PCF vs ISO vs other.
The first phase is the goal and scope definition for conducting the PCF. Goal definition includes choosing an intended audience and providing them with reasons for carrying out the study. Additionally, reasonings would include intended applications that can be product development and improvement, strategic planning, public decision-making, and marketing. On the other hand, the scope definition includes deciding the reference flow, function, and functional unit; making initial choices of setting a system boundary, and reviewing data quality (Refer to key terminology). Here is a breakdown of the requirements under this step:
We begin with choosing the final product to be studied. The studied product is the product on which the GHG life cycle inventory is performed. Once finalised we move on to deciding the unit of analysis and deciding the functional unit. Like the unit of analysis, the functional unit is defined as the performance characteristics and services delivered by the product being studied. A defined functional unit typically includes the function (service) a product fulfills, the duration or service life (amount of time needed to fulfill the function), and the expected quality level. Here are a few examples of wall paint and a cup of coffee for you to get an idea:
Services:
Beverages:
IT Solutions:
A well-defined functional unit consists of three general parameters:
Although not all parameters may be relevant for all products (or some parameters may be mutually exclusive), considering them helps to ensure robust functional unit definition and makes subsequent inventory steps easier, such as defining the use during boundary setting (GHGP Product Standard Chapter 6).
Identifying and selecting the function is a critical aspect of a PCF. When the function is known (i.e., for final products and some intermediate products), the unit of analysis is the functional unit. Some questions a company may ask to help identify a product’s function include:
“If multiple functions are identified, companies should base the functional unit on the function(s) that best reflects what the studied product was designed to do.” (GHGP Page 30)
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“A review or screening exercise of all the products a company produces, distributes, buys, or sells is the first step to identifying an individual product to study. Companies should pick a product that is GHG intensive as well as strategically important and aligned with their business goals.”
If you have never identified GHG-intensive products or categories before, “companies may use physical or economic factors to rank products by mass, volume, or spend.
Source: GHGP Product Standard Page 29
The boundary of the product life cycle greenhouse gas inventory encapsulates all attributable processes. Any exclusions from the inventory must be reported, along with a justification for their omission. This helps to ensure that companies are not selectively omitting significant processes to present a more favorable environmental profile.
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Gate-to-Gate focuses on a specific segment of the production process and is best used within a single facility or process step. For paint, this might involve evaluating only the manufacturing processes, such as mixing, blending, and packaging, along with the energy consumption and waste generation within the manufacturing plant, without considering the upstream raw material extraction or the downstream impacts of product use and disposal.
For final products, the inventory boundary extends from cradle-to-grave, encompassing the entire life cycle from raw material extraction to end-of-life disposal. This comprehensive approach ensures that all significant environmental impacts are captured. In the case of a cradle-to-gate partial life cycle inventory, the boundary excludes product use and end-of-life processes. Companies must disclose and justify the use of a cradle-to-gate boundary in their inventory report, ensuring transparency and allowing stakeholders to understand the limitations of the inventory.
The time period of the inventory and the method used to calculate land-use change impacts (if applicable) must also be reported by companies. This information helps to ensure the reliability and comparability of the inventory results. The time period should be representative of the product's life cycle and the method used to calculate land-use change impacts should be consistent with recognized standards and methodologies.
By adhering to these requirements, companies can ensure that their product life cycle greenhouse gas inventories are comprehensive, transparent, and reliable. This information is essential for stakeholders to understand the environmental impacts of products and make informed decisions.
Following the lifecycle stage definitions, develop a detailed flow diagram showing all the processes involved from the beginning of the life cycle to the end. This should include all inputs and outputs for each process stage. Finally, mark on the diagram where data needs to be collected. This includes energy usage, raw material inputs, waste outputs, etc.
Developing a process map is an important requirement when completing an inventory, since processes and flows identified in the process map are the basis for data collection and calculation. Here is an illustration of a cradle-to-grave process map for a final product.
Let’s begin mapping, you can use our template to start identifying processes and follow the steps below:
Description: Identify the defined life cycle stages at the top of the map, from material extraction through to end-of-life (or production for cradle-to-gate inventories).
Description: Identify the position on the map where the studied product is finished and exits the reporting company’s gate.
Description: Identify component inputs and upstream processing steps necessary to create and transport the finished product, aligning the processes with the appropriate life cycle stage.
Description: Identify the energy and material flows associated with each upstream process, including inputs that directly impact the product’s ability to perform its function and outputs such as waste and co-products.
Description: For cradle-to-grave inventories, identify the downstream processing steps and energy and material flows needed to distribute, store, and use the studied product.
Description: For cradle-to-grave inventories, identify the energy and material inputs needed for the end-of-life of the studied product.
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The step after inventory modeling is gathering data on all processes and activities within the system boundary. Undergoing this step systematically will help you organize and consistently document the needed data. This includes data on raw materials, energy consumption, transportation, manufacturing processes, product use, and end-of-life disposal.
The seven steps mentioned below should provide a guide to follow. Depending on the product chosen, mapping conducted, and resources available you can expand or condense this list as explained in the example.
Activity Data Activity data are the quantitative measure of a level of activity that results in GHG emissions. Here are two categories with examples:
Primary data are defined as data from specific processes in the studied product’s life cycle. It usually includes direct emissions data and process activity data, which are physical measures of a process that results in GHG emissions or removals. These data capture the physical inputs, outputs, and other metrics of the product’s life cycle. Examples of primary data include:
Secondary data refers to information that is not directly related to specific processes within the product's life cycle under study. Any direct emission or process activity data that does not qualify as primary data falls into the category of secondary data. Additionally, financial activity data cannot fulfill the primary data collection requirements and are therefore always considered secondary. Examples of secondary data include:
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The Bill of Materials (BoM) lists all the parts and materials in a product. Breaking down the product helps you understand what's included in your assessment and lays the groundwork for the inventory.
On the right is a sample BoM for a shoe.
Think of a Bill of Materials (BoM) as a detailed recipe for your product, listing every ingredient (raw material) and their quantity. This "recipe" is crucial for calculating your product's carbon footprint. It helps you identify which materials have the highest environmental impact, track their origins to assess transportation emissions, and ultimately calculate the overall embodied emissions by combining material quantities with emission factors for each component. Essentially, the BoM provides the foundational data for understanding your product's environmental impact from its very building blocks.
Emissions calculations can be done in a variety of ways, but Breeze is our top choice of platform for measuring both organization scope 1, 2, and 3 emissions and product/service emissions. Use the Projects feature in your Breeze account to complete the next steps.
As you begin to multiply emission factors with the activity data to calculate GHG emissions, it is important to choose the correct emission factor and document the reasoning behind the selection. The types of emission factors needed depend on the types of activity data collected. They can be found in life cycle databases, published product inventory reports, government agencies, industry associations, company-developed factors, and peer-reviewed literature.
Emission factors are the GHG emissions per unit of activity data, and they are multiplied by activity data to calculate GHG emissions. Emission factors may cover one type of GHG (for example, CH4/liter of fuel) or they may include many gases in units of CO₂ₑ.
Once data is collected and emission factors are selected, the next step is to calculate the total GHG emissions for each process and activity. For this, first you shall apply a 100-yr GWP. Although it is required for companies to calculate using 100-yr GWP, you may choose to calculate and report on 20-yr or 500-yr GWP separately.
Data gaps exist when there is no primary or secondary data that is sufficiently representative of the given process in the product’s life cycle.
Proxy data are data from similar processes that are used as a stand-in for a specific process. Proxy data can be extrapolated, scaled up, or customized to represent the given process. You may customize proxy data to more closely resemble the conditions of the studied process in the product’s life cycle if enough information exists to do so.
If you cannot collect proxy data to fill a data gap, companies should estimate the data to determine significance. If processes are determined to be insignificant based on estimated data, the process may be excluded from the inventory results.
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The global warming potential (GWP) is a metric used to calculate the impact of multiple greenhouse gases (GHGs) in a comparable way. All GHGs are not equal. Each one has a unique atmospheric lifetime and heat-trapping potential. The GWP metric examines each greenhouse gas’s ability to trap heat in the atmosphere compared to carbon dioxide (CO₂).
GWPs are published in aggregated form as part of the IPCC Assessment Reports.
The following equations illustrate how to calculate CO₂ₑ for an input, output, or process based on activity data, emission factors, and GWP.
Once the inventory results in CO₂ₑ are calculated, you need to ensure that all results are on the same reference flow basis. For example, if the reference flow for the studied product is 10 kg and the inventory results are per kg of product, all the inventory results need to be multiplied by 10. Because the reference flow represents to amount of product needed to fulfill the unit of analysis, results on the reference flow basis are summed together to calculate the total CO₂ₑ/unit of analysis.
See the below example from Cafe Binocle:
In most products, there is at least one common process that has multiple valuable products as inputs or outputs, and for which it is not possible to collect data at the individual input or output level. In these situations, the total emissions or removals from the common process need to be partitioned among the multiple inputs and outputs. This partitioning is known as allocation.
In cases where processes serve multiple products, it is necessary to allocate GHG emissions to each product based on an appropriate allocation method. Common allocation methods include mass, economic value, and energy content.
Here are the three most commonly used methods with an example of two products, Product A and Product B, sharing a process generating 300 kg of CO₂ₑ.
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If a physical relationship between the studied product, co-product, and the emissions and
removals of a common process is not applicable or cannot be established, then companies should use economic or other relationships. Physical relationships cannot be established when the following conditions apply:
Source: GHGP Product Standard Page 70
Assessing uncertainty is a critical step in the Product Carbon Footprint (PCF) process because the audience for a product inventory report is diverse, you should make a thorough yet practical effort to communicate the level of confidence and key sources of uncertainty in the inventory results. It helps ensure that the results are robust and reliable. It provides a clear understanding of potential variations in the calculated greenhouse gas (GHG) emissions as uncertainty can arise from several sources, including data quality, methodological choices, and assumptions made during the inventory modeling process.
Accuracy: Understanding uncertainty helps in improving the accuracy of the PCF.
Decision-Making: It provides confidence in the results, enabling better decision-making regarding product design, supply chain management, and sustainability strategies.
Transparency: Communicating uncertainty levels enhances the transparency of the PCF results to stakeholders.
Example of Uncertainty assessment
Ensuring the accuracy and reliability of the data is crucial. This involves verifying data sources, checking calculations, and documenting assumptions and methodologies.
Quality Assurance Steps:
For best practices in quality assurance, see the ISO 14044 standard.
The final step involves assessing the overall impact of the product's carbon footprint. This involves aggregating the GHG emissions from all processes and activities within the system boundary and evaluating their significance.
Key Steps in Impact Assessment:
Reporting the results of a Product Carbon Footprint (PCF) is the final step in the process and is crucial for communicating the findings effectively to both internal and external stakeholders. A well-prepared report ensures transparency, facilitates decision-making, and supports the company’s sustainability goals by highlighting key areas of improvement and success.
The journey to understanding and calculating a Product Carbon Footprint (PCF) is not only a vital step in managing and reducing greenhouse gas emissions but also an opportunity to align your company’s products and services with the growing demand for sustainability. This guide has walked you through the process, from defining the goal and scope of your PCF to reporting the final results with transparency and clarity.
As you apply the principles and steps outlined in this guide, remember that the landscape of sustainability is constantly evolving. New technologies, standards, and consumer expectations will continue to shape how companies approach carbon footprinting and environmental responsibility. Stay informed, be adaptable, and remain committed to reducing your impact on the planet. This guide is a starting point, and the real impact comes from putting these practices into action.
This guide and methodology were developed by co-authors Ansh Arora and Muhammad Konain, supported by Lucas Fraser, in collaboration with the UBC SME Climate Clinic.