The Big Guide to Scope 3 Emission Factors (2025): What to Use, When, and Where to Get Them

If you want this guide to double as your day to day reference, bookmark it. It covers the most used Scope 3 emission factor (EF) sources: what they're good for, where they fall short, and exactly where to get them. It includes national factor sets, LCI databases, EEIO/MRIO models, sector methods, and platforms like DitchCarbon for supplier-specific (primary) vendor/SKU level factors.

How to Use This Guide

• Pick by data type:
  • Activity/National sets for quick coverage (travel, freight, waste, upstream fuels).
  • LCI databases for product/material specificity.
  • EEIO/MRIO for spend-based screening and gap-fill, using industry-average (secondary) factors ahead of supplier-specific (primary) data.
  • Sector methods for logistics/aviation with activity data (primary data).
  • Supplier specific platforms to turn averages into supplier level action.
• Document everything: record source, version, link, date for audit.
• Refresh annually: most factor sets update yearly; methods less often.

Quick Comparison (by Category)

National / Company-Reporting Factor Sets

UK Government GHG Conversion Factors (DESNZ/Defra)

What it is: The UK's canonical annual EF pack for company reporting (travel, freight, waste, fuels, etc.).Use when: You need quick, auditor-familiar Scope 3 coverage; UK or international operations.Access: GOV.UK 2025 factors • Methodology paper (PDF).

New Zealand: Measuring Emissions (MfE)

What it is: Official NZ factors and guidance for organisations.Use when: NZ entities or global firms with significant NZ activity.Access: Measuring emissions guide: 2025 (and update note).

Australia: National Greenhouse Accounts (NGA) Factors (DCCEEW)

What it is: Annual Australian factors (Scope 1-3, incl. upstream fuels).Use when: AU reporting or operations; grids and fuels localised to AU.Access: NGA Factors 2025 page • PDF • XLSX.

US EPA - WARM (waste factors)

What it is: A scenario/model-based tool with EF documentation for waste/material pathways (landfill, recycling, composting, etc.).Use when: Waste Scope 3 categories; comparing waste management options.Access: WARM homepage • Version history • Factor documentation.

EEIO / MRIO (Spend-Based) Models

US EPA - USEEIO

What it is: US environmentally extended input-output models for spend-based intensities across commodities and industries.Use when: Broad Scope 3 screening with financial data; US-centric analyses.Access: USEEIO models page • Technical content • GitHub.

EXIOBASE (global MRIO)

What it is: Global multi-regional EEIO tables with environmental extensions.Use when: International spend-based Scope 3 screening and trade-linked analysis.Access: EXIOBASE site and intro/registration pages.

Eora MRIO (global)

What it is: Global MRIO with environmental & social satellite accounts (190 countries).Use when: Global supply-chain screening; country-level granularity.Access: Eora (worldmrio.com) • Documentation.

WIOD (World Input-Output Database)

What it is: Research-grade world IO tables (historic coverage), used for international analysis.Use when: Academic/long-run studies; supplementary spend-based insights.Access: WIOD (University of Groningen) • 2013 release page.

CEDA (Comprehensive Environmental Data Archive)

What it is: An EEIO/MRIO dataset; Open CEDA announced as a free version in 2025.Use when: Spend-based Scope 3 where global coverage and sector breadth are needed.Access: GHG Protocol profile • Watershed CEDA • Open CEDA announcement.

Sector Methods (Logistics, Aviation)

GLEC Framework (Smart Freight Centre) - ISO 14083 Aligned

What it is: The industry method for calculating logistics emissions across modes; includes default intensities and calculation rules.Use when: Freight Scope 3 (road/air/sea/rail); aligning with carriers and platforms.Access: GLEC overview • GLEC v3 PDF.

ICAO Carbon Emissions Calculator / Methodology

What it is: Recognised aviation methodology and factors for flight emissions (passenger and cargo variants).Use when: Business travel and air-freight allocations; route/aircraft assumptions needed.Access: ICAO ICEC • Methodology v13 (PDF).

LCI Databases (Process/Product)

ecoinvent

What it is: Leading global LCI database (tens of thousands of datasets) for product/material footprints.Use when: Purchased goods & services, capital goods, and supplier dialogues that require specificity.Access: ecoinvent database • v3.11 release notes.

Sphera / GaBi (Managed LCA Content)

What it is: Commercial LCI datasets with deep industrial coverage; updated regularly; integrates with GaBi and other tools.Use when: Product-level Scope 3 requiring industry-grade datasets.Access: Managed LCA Content • LCA data portal.

EU Environmental Footprint (EF/PEF)

What it is: EF-compliant LCI datasets supporting Product/Organisation Environmental Footprint rules in the EU.Use when: EU customer/PEF requests; EU policy alignment.Access: EPLCA EF hub (see node info & access pathways).

ADEME - Base Carbone

What it is: France's public EF database covering activities and some product-like entries; widely used in FR/EU.Use when: France reporting or EU activity factors; complementary to EF/LCI sets.Access: Base Carbone (open data) • Methodology docs.

NREL - U.S. LCI Database

What it is: Open U.S. LCI datasets maintained by NREL.Use when: US-centric product/material modelling and as a complement to ecoinvent/Sphera.Access: USLCI portal.

Germany UBA - PROBAS

What it is: Free process-oriented data from the German Environment Agency; useful for LCA and reporting.Use when: EU/German context; additional process data alongside EF/ecoinvent/Sphera.Access: PROBAS.

Japan - IDEA (Inventory Database for Environmental Analysis)

What it is: National LCI database covering most Japanese economic activities.Use when: Japan suppliers/materials; regionalised LCI for product footprints.Access: IDEA official site.

China - CLCD (Chinese Life Cycle Database)

What it is: Chinese national LCI (available via eBalance / IKE); useful for China-specific supply chains.Use when: China suppliers/materials; localisation of product EF.Access: GHG Protocol CLCD profile (with links) • (vendor) IKE.

AGRIBALYSE (ADEME)

What it is: Reference LCI for agri-food products in France/EU.Use when: Food & catering categories; farm-to-fork analyses.Access: AGRIBALYSE portal • Data/documentation (EN).

Worldsteel LCI

What it is: Global steel LCI datasets (cradle-to-gate, with recycling method options).Use when: Materials modelling for steel; supplier/manufacturer conversations.Access: Worldsteel LCI page • LCI data request.

Supplier Specific Platform

DitchCarbon (supplier specific spend/activity/product factors)

What it is: A platform that maps your spend, activity, and product to supplier specific factors (vendors/SKUs), connecting curated references with real supplier data for actionable Scope 3 reductions.Use when: You want to move from averages to procurement-level action: prioritising suppliers, quantifying initiatives, and tracking progress.Access: DitchCarbon.

Where Each Source Shines (and What to Watch)

• National sets (UK, NZ, AU, US-WARM) - rapid coverage for common categories; great for policy compliance. Watch: geographic specificity; not product-level.
• EEIO/MRIO (USEEIO, EXIOBASE, Eora, WIOD, CEDA) - perfect for screening and gap-fill using financial data. Watch: averages hide supplier differences; complement with LCI/supplier specific data.
• LCI (ecoinvent, Sphera/GaBi, EF/PEF, Base Carbone, NREL USLCI, PROBAS, IDEA, CLCD, AGRIBALYSE, Worldsteel) - product/material specificity for supplier engagement and design decisions. Watch: licensing and coverage vary; mix sources wisely.
• Sector methods (GLEC, ICAO) - standardisation for logistics and aviation; aligns partners and tools. Watch: works best with activity data; add non CO₂ policy uplift where required.
• Supplier specific (DitchCarbon) - turns datasets into vendor/SKU-level factors for procurement decisions and measurable reductions. Watch: integration and supplier data depth.

Implementation Playbook (Keep It Simple)

1. Baseline coverage: Use your national set (UK/NZ/AU or US WARM + USEEIO).
2. Logistics standardisation: Apply GLEC (ISO 14083 aligned) and gather tonne-km/fuel/load data.
3. Product depth: Add ecoinvent / Sphera/GaBi and EF/PEF/Base Carbone where relevant; use USLCI/PROBAS/IDEA/CLCD/AGRIBALYSE for regional specificity.
4. Supplier action: Layer DitchCarbon to map spend/activity/product to supplier specific factors and track reductions.
5. Aviation policy: Use ICAO methodology; add non CO₂ uplift per your reporting policy.
6. Governance: Log source, version, link, and date in your inventory policy; refresh annually.

One-Stop Links (Official Sources)

• UK DESNZ/Defra, GHG Conversion Factors (2025): GOV.UK page; methodology PDF.
• US EPA, WARM: Homepage; versions; documentation chapters.
• US EPA, USEEIO: Models page; technical content; GitHub.
• EXIOBASE: Main site; welcome page.
• Eora MRIO: Main site; docs.
• WIOD: University of Groningen pages.
• CEDA: GHG Protocol profile; Watershed CEDA; Open CEDA.
• GLEC Framework (SFC): Overview; v3 PDF.
• ICAO ICEC: Tool; v13 methodology.
• ecoinvent: Database; v3.11 update.
• Sphera/GaBi: Managed LCA Content; dataset portal.
• EU EF/PEF: EPLCA hub for EF.
• ADEME, Base Carbone: Dataset portal; methodology docs.
• NREL, U.S. LCI: USLCI portal.
• UBA, PROBAS: Portal.
• Japan, IDEA: Official site.
• China, CLCD: GHG Protocol profile; IKE vendor site.
• AGRIBALYSE: Portal; data access/doc (EN).
• Worldsteel LCI: LCI page; request form.
• New Zealand MfE: 2025 guide.
• Australia NGA (DCCEEW): 2025 page; PDF; XLSX.
• DitchCarbon: Supplier specific factors and procurement workflows. (Internal link above)

Final Tips for Sustainability & Procurement Teams

• Mix and match deliberately: Use national sets for coverage, GLEC for logistics, ecoinvent/Sphera (and EF/Base Carbone/USLCI/PROBAS/IDEA/CLCD/AGRIBALYSE) for product depth, USEEIO/EXIOBASE/Eora/WIOD/CEDA for screening, and DitchCarbon to turn it all into supplier level actions.
• Be explicit about assumptions: Geography, year, units, allocation, and non CO₂ treatment (e.g., aviation uplift) can move results. Cite your sources and versions every time.
• Plan your refresh cycle: Put a calendar reminder for annual updates (UK, NZ, AU, many LCI sets). Track versions in your inventory policy so auditors (and future you) can reproduce results.

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