This document summarizes the updates to U.S. EPA's Supply Chain Greenhouse Gas (GHG) Emission Factors, including the transition from legacy versions (v1.1 and v1.2) to corrected versions (v1.1.1 and v1.2.3), and the adoption of the newest set of factors - v1.3. It covers why these updates were necessary, how factors were reproduced, implications for Workiva Carbon, and what actions customers should take.
| Factor Version | Key Issues & Reasons for Update | Resolution |
|---|---|---|
| v1.1 | EPA calculation errors in summary models, incorrect values for “other gases” in v1.1 EPA model, incorrect GWPs applied during implementation | Replaced by v1.1.1 |
| v1.2 | Typo mislabeling HFC/PFC units original EPA publication (kg vs kgCO2e) led to incorrect GWP values being used for HFCs & PFCs during implementation, WKC mistakenly applied incorrect GWP values to other gases as well during implementation, EPA error during build of industry models in original v1.2 (corrected in v1.2.3), Workiva previously applied own method to crosswalk and build the factors which yielded different results than the methods built into the published EPA models and lacked sufficient traceability and auditability -> updating to align with EPA methodology and improve traceability | Replaced by v1.2.3 |
| v1.3 | Newest EPA-published version, EPA fixed past issues, aligned with 2022 GHG data and 2022 dollar year to better model more recent spend-based transaction | Newly added |
| Version Update | EPA Explanation |
|---|---|
| v1.1 -> v1.1.1 |
|
| v1.2 -> v1.2.3 | |
| Model Version | BaseIOLevel | Commodity/Industry | DisaggregationSpecs | Mapping to NAICS | Output Type |
|---|---|---|---|---|---|
| v1.1.1 | Summary | Industry | N/A | Removed | BEA Industry Summary |
| v1.2.3 | Summary | Industry | Set to null (N/A for summary level) | Removed | BEA Industry Summary |
| v1.3 | Summary | Industry | N/A | Removed | BEA Industry Summary |
*For more detailed guidance on reproducing the factors see Workiva Carbon's EPA EEIO factor generation method.
| File Name | Description |
|---|---|
| SupplyChainGHGEmissionFactors_v1.3.0_BEA-IS_CO2e_USD2022.csv | CO2e factors by BEA Summary Industry (in 2022 USD) |
| SupplyChainGHGEmissionFactors_v1.2.3_BEA-IS_CO2e_USD2021.csv | CO2e factors by BEA Summary Industry (in 2021 USD) |
| Area | Guidance |
|---|---|
| Accuracy | Emissions calculated using v1.1 or v1.2 may contain material inaccuracies. |
| Audit Readiness | Aligning with v1.3, v1.2.3, and v1.1.1 enhances traceability, accuracy, and alignment with EPA methodology |
| What to Do | Recalculate historic data where material; document which factor version was used. |
For further technical documentation and the R code used to generate these factors, visit: https://github.com/USEPA/supply-chain-factors/releases
Who is impacted by these factor updates?
Workiva Carbon customers who have entered data in the Purchases category. This specifically affects the following GHG Protocol categories:
Why are we making this change?
Simple Explanation: We're updating how emission factors are derived in the Purchases category to reflect new and improved data and calculation methods made available by the EPA. These updates ensure that your emissions are calculated using the most accurate and up-to-date information, based on the latest guidance and datasets.
Detailed, Technical Explanation: The updates to U.S. EPA's Supply Chain Greenhouse Gas (GHG) Emission Factors, including the transition from legacy versions (v1.1 and v1.2) to corrected versions (v1.1.1 and v1.2.3), and the adoption of the newest set of factors - v1.3. It covers why these updates were necessary, how factors were generated, implications for Workiva Carbon, and what actions customers should take.
Should customers recalculate the data and use the latest emission factors?
We recommend that all customers consider recalculating their emissionsusing the updated factors. Keep in mind, these recalculations will impact previous organizational reporting and disclosures (e.g. Voluntary reporting, CDP, SBT commitments, customer-required reporting, etc.)
Will we have other, future emission factor changes?
Yes. Workiva Carbon regularly updates and maintains its emission factor library to improve accuracy, granularity, and auditability over time. We also know that customers are asking for more flexibility —including the ability to choose between different emission factor datasets, customize factor application logic, and more easily manage recalculations. These are valuable enhancements, and we see them as a benefit we’re actively working to expand within the product. In addition to this update, we are conducting a broader review of our emission factor library, and future enhancements are likely as our methodology evolves. We’ll continue to communicate about any future changes and share more as new capabilities become available.
How can customers apply the new emission factors for the Purchases data?
Once we release a product update to make the new emission factors available, customers can recalculate by:
How can customers apply the new emission factors for the Transportation & Distribution data?
Once we release a product update to make the new emission factors available, customers can recalculate by:
Does this only impact U.S. customers?
No. While the EEIO dataset is published by the U.S. EPA, Workiva applies it globally in the standard Purchases calculator. Customers in any region may be impacted if they use the default logic.
Does this impact any Scope 1 or Scope 2 calculations?
No. This current update does not impact any Scope 1 or Scope 2 calculations. However, we are actively reviewing all emission factors as part of a broader initiative. While these current changes don’t impact Scope 1 or 2, future updates may occur based on the outcome of that review. If so, we will communicate those changes directly.
Can I opt out of this update if my company still wants to use the previous EEIO dataset?
Yes. No changes will be applied automatically to historic uploads. To apply the updated EEIO emission factors, you must add new data or manually initiate a recalculation.
If your company prefers to continue using the prior logic for now, simply do not recalculate. This means:
Do not adjust your Purchases category mapping, as even a minor change and re-save will trigger a recalculation using the new logic.
Additionally, do not add new data into a reporting year unless you would like to opt into the new factors.
Please note that any new Purchases data added going forward will use the updated EEIO logic by default. We recommend recalculating to align with the most current and accurate data, but the decision is up to you.
What is the purpose of EEIO spend-based emission factor estimates?
Spend-based estimates from the EEIO dataset are used when a company is unable to obtain actual emissions data directly from a supplier. This approach provides a reasonable approximation based on economic activity (dollars spent) and is a widely accepted method for filling data gaps in Scope 3 inventories. These estimates are often used to identify emissions "hot spots" across your value chain. Once high-impact areas are identified, the recommended next step is to engage directly with suppliers to collect more accurate, activity-based emissions data over time.
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