Freight emission calculation rules and standards
Methodology posts
Posts on the GLEC Framework v3.2, ISO 14083:2023, WTW/TTW/WTT, data quality tiers, and how each piece of the calculation actually works. The closest thing to the engine documentation, written for the auditors who will check it.
5 posts in this category
methodology
GLEC Framework v3.2 vs UK DEFRA emission factors — which one to use when
DEFRA is simpler for UK-only SECR reporting. GLEC is the right base for any lane that crosses a border or any shipper that reports to CDP or CSRD. The 8% gap on UK heavy truck, the LNG and biofuel and reefer divergences, and my honest opinion on which way to point a calculator.
methodology
GLEC Framework vs ISO 14083:2023 — how they fit together, and what you have to choose between
GLEC is the factor table. ISO 14083 is the methodology. They sit on top of each other, not next to each other. What each one specifies, where they overlap, and what changes on the same shipment when you swap the methodology stack underneath the GLEC factors.
methodology
GLEC v3.0 vs v3.2 — what changed in the freight emission factor tables
If your calculator is on v3.0, what do your numbers do when you upgrade to v3.2? Same Shanghai-Rotterdam shipment in both versions, the percent move by mode, when to migrate, and whether to restate the prior year.
methodology
GLEC v3.2 in Detail: What Changed from v3.0 and v3.1, and What Changes Again in v4
GLEC v3.2 is the current edition; v4 is in draft. Five changes between v3.0 and v3.2 actually move numbers in production calculators — container ship segmentation, LNG WTW, articulated truck lane utilisation, belly cargo allocation, and a separate hub line item. Here's each one with the percent impact.
methodology
GLEC v3.2 in Practice: Freight Emission Calculation with Worked Examples
We walk through three real emission calculations — a 40ft container Shanghai to Rotterdam, a truck from Munich to Milan, and an air cargo pallet LAX to Narita — showing every formula, factor, and assumption.