Open CEDA: Free emission factors for supply chain emissions

Scope 3 emissions, the indirect greenhouse gas (GHG) emissions which typically stem largely from your supply chain, are often the hardest of GHG emissions to measure. Not because you don’t know your supply chain, but because finding accurate, relevant, and consistent emission factors is not easy.  

We know many consultants use the freely available US EPA emission factors, but we’ve steered clear from this because at Rawstone we have only a small US client-base and the emissions associated with the production of goods in the US are simply not the same as those that you would find in the UK (or elsewhere), even when adjusted for inflation and currency (just think of the electricity fuel source and transport differences, for example).  

But for those companies that have been using US EPA factors, there is now another spanner in the works – the Trump Administration has put an end to their publication - and so for many, new emission factors sources will need to be found. 

Our solution, which we’ve used for several years now, are the CEDA emission factors from Watershed. These are country-specific emission factors that allow easy conversion of supply chain spend into industry-specific GHG emissions. We’re pleased to share that in response to the removal of US EPA emission factors, and reflecting Watershed’s commitment to impact, they have made a slimmed-down version of their dataset available in the form of Open CEDA. 

In this post, we will introduce the Open CEDA database, what this means to your business and when the main ‘Enterprise’ version of CEDA may still be more appropriate for your company. 

Introducing Open CEDA 

Open CEDA was released in May 2025, and we understand will be updated annually going forward. It comes in the format of an MS Excel database of 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 using the recognised environmentally extended input-output (EEIO) model, plus robust scientific review CEDA ensures credibility and accuracy. 

• Globally relevant: the database includes 60,000 emission factors across 149 countries, in a range of currencies and covering 400 industries. 

• Fit for purpose: conforms with the spend-based method calculations allowed under the GHG protocol and SBTi. 

  
  

What this means to your business 

Open CEDA is making supply chain GHG emission calculations more accessible to the masses. It empowers those that haven’t previously calculated their supply chain emissions to do so themselves, thus laying the foundations for identifying hotspots, prioritising decarbonisation efforts and ultimately accelerating progress towards net-zero. 

For those companies that have previously measured their supply chain emissions using US EPA sources, CEDA is providing a new, more country-specific solution. This will improve accuracy but companies with targets that are making this change should be mindful to retrospectively apply the CEDA emission factors to their base year, because this is a methodology change. If the new emission factors change the base year emissions significantly (use the SBTi’s 5% threshold as a guide here) a restatement will be required and from our experience this is a highly likely scenario.  

When companies may still need to use Enterprise CEDA 

While Open CEDA provides a strong foundation for many companies' scope 3 supply chain calculations, some organisations have specialised reporting needs that go beyond the open dataset. This is where the Enterprise CEDA version comes in. 

Your company might need the Enterprise version if: 

1. You supply chain has any FLAG emissions: Forest, Land and Agriculture (FLAG) emissions are those that arise from land management and land use change. They are particularly relevant for companies that operate in agriculture; forestry; food and beverage; and apparel and textiles sectors. Open CEDA includes some land management emissions in their factors but when FLAG emissions are significant, these should be isolated and reported separately to non-FLAG emissions. Enterprise CEDA allows for this by providing spend-based and weight-based FLAG emission factors for 150 additional agricultural commodities. A threshold of 20% FLAG emissions is often understood to be where they become significant (and segregation is important based on SBTi target requirements). However, we would suggest that it is beneficial for companies with much lower FLAG emissions to calculate them separately, because it ultimately improves the accuracy of the footprint and makes emissions reductions easier. Land management emissions are not easy to reduce.  

2. You need to meet a scope 3 target: Moving to supplier-specific emissions is the primary way to realise supply chain emission reductions (read why in our blog here), and thus it is essential for meeting scope 3 reduction targets. Unfortunately, when suppliers don’t have their full scope 1, 2 and 3 GHG footprint measured, their data can’t be used. Enterprise CEDA however changes this as it breaks down the industry emission factors into those relating to a supplier’s scope 1 and 2, and those relating to a supplier’s scope 3 sources. This means that companies can switch to at least partial supplier-specific emissions as soon as their supply chain are measuring their scope 1 and 2 emissions, without waiting for all their scope 3 to be measured. For manufacturing suppliers (who generally have a higher proportion of scope 1 and 2 emissions than service-based suppliers) this is particularly relevant and enables earlier reflection of supply chain emission reductions in your reported numbers.  

   
   

It's for these reasons that we use the Enterprise version for all our clients. We know that they will achieve emission reductions and their targets more quickly this way. 

Ready to get started? 

Is your business ready to leverage Open CEDA? Here’s how: 

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

• Read up on supporting documentation: Check out CEDA’s FAQ’s and methodologies

  
  

If you need support with restatements arising from changing to Open CEDA, or want support to implement Enterprise CEDA and/or set carbon reduction targets, contact us here. 

Authored by Amy Whitcher.