What is the GLEC Framework v3.2?

The Global Logistics Emissions Council (GLEC) Framework is the industry-standard methodology for calculating logistics greenhouse gas emissions, published by Smart Freight Centre. Version 3.2 is the current edition as of 2026 (v4 is in draft). It supplies emission factors for road, sea, rail, and air freight that are aligned with ISO 14083:2023.

What is ISO 14083:2023?

ISO 14083:2023 specifies the methodology for quantifying and reporting greenhouse gas emissions arising from transport chain operations. It defines how to allocate emissions across legs of a multimodal shipment, how to handle hub and transshipment emissions, how to treat empty running, and which data quality tiers count as compliant. GLEC supplies the factors; ISO 14083 supplies the rules for applying them.

What is the difference between WTW, TTW, and WTT?

WTW (Well-to-Wheel) is the total lifecycle emission — fuel production plus combustion. TTW (Tank-to-Wheel) is combustion only. WTT (Well-to-Tank) is fuel production only. WTW = TTW + WTT. CSRD Scope 3 and GLEC both require WTW. EcoFreight returns all three so the caller can plug straight into whichever disclosure framework an auditor wants.

What are ISO 14083 data quality tiers?

Three tiers. Primary: metered fuel burn on the specific trip you are reporting. Secondary: modelled from carrier or lane data (e.g. vessel-IMO-number matching, dedicated-lane fuel intensity). Default: GLEC sector-average factors. ISO 14083 explicitly allows mixing tiers across legs of a single shipment provided you disclose the tier used for each leg.

Does the methodology include radiative forcing for air cargo?

No. Air freight factors are CO2-only. IPCC AR6 puts aviation's full climate impact at 1.7-3x the CO2 number depending on altitude and contrail conditions, but the multiplier is methodologically unsettled and most CSRD disclosures still report CO2-only. We flag the radiative forcing question in the response metadata so callers can footnote it consistently.

Calculation Methodology

Name: EcoFreight Freight Emissions API
Brand: EcoFreight
Availability: InStock

Based on the GLEC Framework v3.2 and ISO 14083:2023 international standards

Important: Our calculations use default (Tier 3) emission factors from the GLEC Framework v3.2. Actual emissions may vary depending on specific vehicle conditions, load factors, fuel type, and operational parameters. For regulatory reporting, we recommend using primary data (actual fuel consumption) when available.

How We Calculate Emissions

EcoFreight calculates greenhouse gas emissions from freight transport using the internationally recognized GLEC Framework v3.2, published by the Smart Freight Centre in October 2025. Our methodology is aligned with ISO 14083:2023 for quantification and reporting of GHG emissions from transport chain operations.

Emissions (kg CO2e) = Activity (tonne-km) x Emission Factor (g CO2e/tkm) / 1000

Where: Activity = Cargo weight (tonnes) x Distance (km)

GLEC v3.2

Emission Factor Source

ISO 14083

Methodology Standard

WTW

Full Lifecycle Scope

Emission Components: WTW, TTW, WTT

WTW — Well-to-Wheel (Total)

Total lifecycle emissions including fuel production and combustion. This is the primary metric we report, and equals TTW + WTT.

TTW — Tank-to-Wheel

Direct emissions from fuel combustion during transport. This is what comes out of the exhaust pipe (zero for electric vehicles).

WTT — Well-to-Tank

Upstream emissions from fuel production, refining, and distribution. For electric vehicles, this includes power plant emissions.

Data Sources

GLEC Framework v3.2 — Smart Freight Centre, October 2025. Default emission factors for all transport modes.
ISO 14083:2023 — International standard for quantification and reporting of GHG emissions from transport chain operations.
IMO MEPC 81 — Marine fuel emission factors for HFO, VLSFO, LNG.
ICAO Carbon Emissions Calculator v11 — Aviation emission methodology.

Download Emission Factor Data

The complete GLEC v3.2 default factor table is available as a flat file for offline use, spreadsheet import, or model training. 27 rows covering road, sea (container, bulk, tanker), rail, and air — each with WTW, TTW, and WTT breakdowns. This CSV is the single canonical source of truth for EcoFreight emission factors.

CSV (8 KB) — glec-factors.csv JSON (12 KB) — glec-factors.json

Released under CC BY 4.0. Cite as: EcoFreight (2026). GLEC v3.2 freight emission factor table. https://ecofreight.co/data/glec-factors.csv

Annual Report

The 2026 State of Freight Emissions

For the mode-by-mode global numbers behind our factor tables, the regulatory map for 2026, and a 2030 outlook, see the third edition of our annual report.

Read the 2026 State of Freight Emissions report →

References

GLEC Framework v3.2, Smart Freight Centre, October 2025
ISO 14083:2023 — Quantification and reporting of GHG emissions arising from transport chain operations
IMO Fourth GHG Study 2020 / MEPC 81 fuel emission factors
ICAO Carbon Emissions Calculator Methodology v11
UK Government GHG Conversion Factors (BEIS/Defra 2024)
EcoTransIT World Methodology Report 2025
EN 16258:2012 — Calculation of energy consumption and GHG emissions in transport
IATA Recommended Practice 1678 — CO2 emissions methodology for air cargo

For publisher details, version numbers, URLs, and last-verified dates, see the full data sources catalogue. For a versioned record of every factor and API change, see the methodology changelog. Definitions for all terms used here — WTW, TTW, WTT, TEU, CII, and others — are in the freight emissions glossary. Build-time measurements of prerender coverage and bundle budgets are on the quality snapshot page.

Questions About Our Methodology?

Our team is available to discuss our calculation methods and help you understand how to use our data effectively.

hello@ecofreight.co

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