Understanding Open CEDA: A Game Changer for Scope 3 Emissions

The Importance of Accurate Emission Factors

Scope 3 emissions are the indirect greenhouse gas (GHG) emissions that primarily arise from your supply chain. They are often the hardest GHG emissions to measure. This difficulty stems not from a lack of knowledge about your supply chain, but from the challenge of finding accurate, relevant, and consistent emission factors.

Many consultants rely on the freely available US EPA emission factors. However, at Rawstone, we have opted for a different approach. Our client base is primarily in the UK, and the emissions associated with the production of goods here differ significantly from those in the US. Even when adjusted for inflation and currency, factors such as electricity fuel sources and transport methods vary greatly.

Recently, the Trump Administration halted the publication of US EPA emission factors. This change means that many companies will need to find new sources for emission factors.

Introducing CEDA Emission Factors

For several years, we have used the CEDA emission factors from Watershed. These country-specific emission factors facilitate the easy conversion of supply chain spending into industry-specific GHG emissions. In response to the discontinuation of US EPA emission factors, Watershed has released a streamlined version of their dataset called Open CEDA.

What is Open CEDA?

Open CEDA was launched in May 2025 and will receive annual updates. It is available as an MS Excel database containing spend-based emission factors that are:

• Open to Everyone: A publicly accessible database with no paywalls.

• Formed from a Robust Methodology: Founded on high-quality national information and employing the recognised environmentally extended input-output (EEIO) model, Open CEDA ensures credibility and accuracy.

• Globally Relevant: The database includes 60,000 emission factors across 149 countries, in various currencies, covering 400 industries.

• Fit for Purpose: Conforms with the spend-based method calculations permitted under the GHG protocol and SBTi.

  
  

What This Means for Your Business

Open CEDA makes supply chain GHG emission calculations more accessible. It empowers companies that have not previously measured their supply chain emissions to do so independently. This capability lays the groundwork for identifying hotspots, prioritising decarbonisation efforts, and ultimately accelerating progress towards net-zero.

For businesses that have previously relied on US EPA sources, CEDA offers a more country-specific solution. This change improves accuracy, but companies should remember to retrospectively apply the CEDA emission factors to their base year. This is crucial as it represents a methodological change. If the new emission factors significantly alter the base year emissions—using the SBTi’s 5% threshold as a guide—a restatement will be necessary. From our experience, this scenario is highly likely.

When to Consider Enterprise CEDA

While Open CEDA provides a solid foundation for many companies' scope 3 supply chain calculations, some organisations have specialised reporting needs that exceed the capabilities of the open dataset. This is where the Enterprise CEDA version becomes essential.

Reasons to Use Enterprise CEDA

Your company might need the Enterprise version if:

1. Your Supply Chain Has FLAG Emissions: Forest, Land, and Agriculture (FLAG) emissions arise from land management and land use changes. These emissions are particularly relevant for companies in agriculture, forestry, food and beverage, and apparel and textiles sectors. Open CEDA includes some land management emissions, but when FLAG emissions are substantial, they should be reported separately from non-FLAG emissions. Enterprise CEDA provides spend-based and weight-based FLAG emission factors for 150 additional agricultural commodities. A threshold of 20% FLAG emissions is often considered significant, necessitating segregation based on SBTi target requirements. However, even companies with lower FLAG emissions should calculate them separately to enhance the accuracy of their footprint and simplify emissions reductions. Reducing land management emissions can be challenging.

   
   

2. You Need to Meet a Scope 3 Target: Transitioning to supplier-specific emissions is crucial for achieving supply chain emission reductions. Unfortunately, if suppliers do not have their full scope 1, 2, and 3 GHG footprints measured, their data cannot be used. Enterprise CEDA addresses this issue by breaking down industry emission factors into those related to a supplier’s scope 1 and 2, and those related to a supplier’s scope 3 sources. This allows companies to adopt at least partial supplier-specific emissions as soon as their supply chain begins measuring scope 1 and 2 emissions, without waiting for all scope 3 emissions to be measured. This is particularly relevant for manufacturing suppliers, who typically have a higher proportion of scope 1 and 2 emissions than service-based suppliers.

   
   

For these reasons, we utilise the Enterprise version for all our clients. We know that this approach enables them to achieve emission reductions and meet their targets more quickly.

Getting Started with Open CEDA

Is your business ready to leverage Open CEDA? Here’s how you can get started:

• Access the Dataset: CEDA by Watershed: Carbon emissions data to drive climate action – Watershed

• Read Supporting Documentation: Check out CEDA’s FAQs and methodologies.

  
  

If you need assistance with restatements arising from the transition to Open CEDA, or if you want support implementing Enterprise CEDA and setting carbon reduction targets, contact us here.

Authored by Amy Whitcher.