The summer of 2025 had multiple milestones for carbon accountants. Watershed and TASA Analytics released “open” versions of their country-level emissions factors and for the first time, practitioners can compare these private-sector datasets against each other and against government sources such as the U.S. EPA’s USEEIO model. For anyone working to quantify Scope 3 GHG emissions, this is a big deal.
To create TASA-EFX (Emissions Factor Exchange), our scientists have spent years building high-resolution, unique country-level models of emissions embedded in supply chains. Our goal has been to help corporations, researchers, and policymakers understand the true carbon cost of global production and consumption. With this data release, TASA is putting into the public domain some of the data we have used privately assisting some of the world’s largest companies.
Introducing TASA-EFX: A Global Supply Chain Lens
TASA-EFX goes beyond traditional “single-tier” emissions factors by making multi-tier supply-chain emissions visible. The dataset covers 148 nations (plus a “rest-of-world” model) and extends ten tiers deep into the supply chain. With more than 9 billion emissions factors and extensions available, TASA-EFX is based on twelve unique national input–output tables and GHG inventories, mirroring the rigor of USEEIO but adding global breadth.
Some standout features:
- Multi-tier visibility. Unlike many databases, TASA-EFX explicitly details the emissions of suppliers’ suppliers, ten tiers deep.
- Nationally aligned data. TASA builds from 12- primary and unique EEIO models covering 65% of global production in countries such as China, Japan, Mexico, and South Korea, then extends these models for global coverage.
- Producer-price orientation. Emissions factors are reported at producer prices rather than consumer prices, allowing users to add their own trade margins instead of relying on blanket assumptions.
- Flexibility for global supply chains. 35,000 industry sector specific rapid LCAs (rLCA) provide the specificity needed for targeted emissions mitigation
How the Datasets Compare
The TASA white paper ‘What’s in a Number?’ compares three major datasets: TASA-EFX Open Silver, Open CEDA, and the U.S. EPA’s USEEIO v2.5 model. The findings:
- TASA-EFX vs. USEEIO v2.5. Nearly identical with only a 0.7% average difference at the sector level. This is not surprising as TASA’s Lead Scientist Yi Yang developed the initial methodology for USEEIO.
- Open CEDA vs. USEEIO v2.5. A mean absolute difference of 17%, with 64 sectors differing by more than 30%.
- Global differences. Across four major economies (China, Japan, Mexico, South Korea), Open CEDA and TASA-EFX differ by –2% to +17% at the national level but show much larger gaps in certain sectors such as natural gas or oil seed production.
The take-home message: overall totals may line up, but the sector-by-sector patterns—and thus the strategic decisions companies make—can vary significantly depending on which dataset they use.
A Hand Mixer Case Study: Scope 3 in Action
To make these comparisons real, TASA modeled a fictional kitchen hand mixer assembled in the U.S. with globally sourced components. Using TASA-EFX Open Silver, the total footprint came to 14.7 kg CO₂e, with more than 90% of emissions embedded deep in the supply chain (Scope 3).
When the same bill of materials was run through Open CEDA, the total footprint was remarkably similar (14.3 kg CO₂e) but the component-level contributions shifted. For instance, Open CEDA assigns more impact to plastics and electronics while TASA-EFX assigns more to steel and metal parts. These differences matter—companies might prioritize different suppliers or mitigation strategies depending on the model chosen.
Why This Matters for Climate Action
The release of open, high-quality Scope 3 data is a breakthrough for several reasons:
- Transparency. Practitioners can now benchmark and cross-validate datasets rather than relying on a single black box.
- Granularity. Multi-tier data helps companies understand not just their direct suppliers but entire upstream ecosystems.
- Strategic insight. With clearer data, businesses can target mitigation measures where they’ll have the biggest impact, whether that’s renewable energy for electronics production or better steel recycling practices.
However, the white paper also underscores that no model is perfect. Methodological choices, producer versus purchaser prices, trade assumptions, sector aggregation, can yield different results. Users should understand these nuances before basing big decisions on a single number.
Looking Ahead
Scope 3 emissions typically represent the majority of a company’s carbon footprint. Yet data gaps, inconsistent methods, and opaque models have long plagued this area of climate action. The simultaneous release of TASA-EFX and Open CEDA suggests a new era of open infrastructure for carbon accounting.
However, progress won’t happen automatically. Model developers must support harmonization and train users to apply the data correctly. Analysts must learn to read between the lines, understanding not only the totals but the sector-level and regional differences that drive them.
As we like to say at TASA Analytics, this is about more than datasets. It’s about creating a shared foundation for effective climate action across global production and consumption systems. With better data, companies can move beyond guesswork and start cutting emissions where it counts.
Bottom line
The summer of 2025 marked a turning point in Scope 3 data availability. For the first time, companies, researchers, and policymakers have access to multiple, comparable, and open global emissions factor datasets. TASA-EFX brings a uniquely detailed, supply-chain-aware lens to this space, one that could reshape how we see and manage carbon footprints for years to come.
Tim Smith
CEO TASA Analytics
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