TASA scientists review and reconcile hundreds of data sources to produce the TASA-EFX global emissions factor database. These includes high-resolution national input-output tables, regional input-output tables (e.g., OECD and EU), GHG inventories (e.g. EPA, ONS, UNFCCC, etc.), global economic data (e.g., U.N. Comtrade, country- and sector-level producer price data), as well as a myriad of academic papers. See our summary tables of original country models in the “Readme” documents for additional information. You can also learn more about the data sources and methods used by exploring our peer-reviewed published papers or contacting our scientists directly. 

TASA’s emissions factors cover all upstream activities (cradle-to-gate) for the industry sector production system, at final demand. This includes GHG Protocol Scope 3 Categories 1, 2, 4, 5, 9 and 15.

TASA provides the most recent and most granular data available from primary governmental sources. Other providers’ models often rely on single country data (e.g., U.S. production systems) to define sectors and sector relationships globally, or are highly aggregated due to global trade modeling constraints. 
 
TASA-EFX provides broad global coverage based on global primary national accounts data representing approximately 70% of global GDP. Global extensions are based on multiple factors, matching technology and development considerations across geographies. In short, TASA provides the most comprehensive multi-region, multi-tier supply chain emissions database available on the market. TASA’s primary global data provides nearly 2.5 billion emissions factors and tier/scope expansions, allowing users to see deep into supply chains. With TASA’s extended global models, reaching 148 countries and one rest-of-world region, users have access to unprecedented visibility into over 9 billion emissions exchanges across nearly 35,000 unique production systems. 

TASA provides dedicated and timely support from its highly trained team of scientists and practitioners. Other providers’ models are either academically led with little continual support, or platform providers with goals that don’t include data quality. All TASA methods are well documented, and continuously reviewed and updated, so you can always be assured that you are using the most accurate information.  

TASA is committed to the continued development and improvement of its methods and data products. Recent, select technical peer-reviewed manuscripts are below (see TASA’s Science Hub for additional papers): 

• Yin, Y., Yang, X.,; Smith, T.M., Yang, Y. Multi-tier supply chains of global semiconductor production and climate mitigation potentials, Environ. Sci. Technol. Forthcoming (2025). 

• Yang, X., Smith, T.M., Prado, A.M., Yang, Y. Net-Zero Greenhouse Gas Mitigation Potential Across Multi-Tier Supply Chains, Commun Earth Environ 6, 230 (2025).  

• Zhang, Y. & Yang, Y. Estimating the carbon footprint of Mexican food consumption based on a high-resolution environmentally extended input-output model. Environ. Sci. Pollut. Res. 31, 27192–27202 (2024). 

• Yang, Y., Park, Y., Smith, T. M., Kim, T. & Park, H.-S. High-Resolution Environmentally Extended Input–Output Model to Assess the Greenhouse Gas Impact of Electronics in South Korea. Environ. Sci. Technol. 56, 2107–2114 (2022). 

• Yang, Y., Ingwersen, W. W., Hawkins, T. R., Srocka, M. & Meyer, D. E. USEEIO: A new and transparent United States environmentally-extended input-output model. J. Clean. Prod. 158, 308–318 (2017). 

TASA-EFX data are structured by national economy-wide models and individual sector-level rapid IO-LCA (rLCA) models. 

• National Model emissions factors are organized to include final-use emissions factors for all available sectors within each country model, providing Scope 1, 2, and 3 breakdowns to allow for targeted exchange of the TASA-EFX factor with primary data. In addition, TASA-EFX National Models provide aggregated emissions contributions by tier and hotspot input contributions for the top 20 tier-1 inputs (direct requirements, by Scope 1, 2, and 3) to facilitate company efforts toward targeted emissions mitigation strategies across multiple supply chain tiers. 

• TASA-EFX Rapid IO-LCA (rLCA) datasets provide deep insights into the emissions structure of individual geographically-specific sector-level supply chains. Each rLCA model provides more than 250,000 unique emissions factors and exchanges across the multi-tier supply chain structure of the production system, identifying where in each supply chain emissions reside for targeted management.  

The country selected should reflect the location of production or activities associated with the product or service system.

Unadjusted TASA emissions factors are approximations of embodied emissions of final demand. Therefore, in spend-based settings, our emissions factors are most appropriately used in direct purchasing situations, where the prices paid for goods/services are reasonably aligned with producer prices – and, where a mix of transportation and logistics agreements (e.g. FOB origin vs. destination, owned vs. 3-party logistics) is embedded in the producers’ costs. 

For purchasing situations where significant intermediate wholesale or retail activities are a known part of the sourcing system, we suggest a partitioning approach such that the purchaser’s price is portioned to account for dollar flows associated with product-service production, intermediate trade activities, and transportation. To account for wholesale or retail trade margins and transportation costs embedded in prices paid by purchasers, TASA’s multi-tier structure allows users to partition spend and apply the appropriate emissions factors to trade and transportation activities specific to your business. Please don’t hesitate to reach out to our support team with your specific questions to help you get the most out of the data.  

TASA provides multi-client licenses for consulting environments or for platform use. The data may be used to prepare reports for your clients and to share the specific emissions factors used in calculations. We encourage transparency and the use of TASA data for creating deep supply chain insights where appropriate to the specific client. However, you may not share the entire database outside of your organization. Please contact us to establish a consulting client relationship or for platform applications.

Yes, the EEIO and hybrid methodologies deployed by TASA are methodologies accepted by all reporting platforms and regulations that refer to the Greenhouse Gas Protocol’s guidelines. TASA’s cutting-edge data products may not be listed on outdated and poorly-maintained “provider lists” (e.g., the GHGP’s provider website hasn’t been updated for years), however, TASA scientists continue to monitor the evolving reporting, disclosure and mitigation landscape to ensure users are basing decisions on the most accurate and up-to-date data available. 

Unlike spend-based data of old, where unsupported data languished and updates were sporadic and unpredictable, TASA’s emissions factor data is continuously updated as new information is made available, so users can be assured that they are using the best and most relevant data possible.

The latest TASA-EFX version (v3.0) was released in September 2024, with each country model including the economic input-output reference year (2013-2018), as well as 2020, 2022 and 2023 model years. Inflationary adjustments are made in late-summer each year. Keep an eye out for new updates, as they occur continuously. 
 
TASA’s rLCA models, by default, are made available for the current model year (e.g., 2023). These data are available for prior years upon request.