A shipper’s freight emissions can climb or fall in a single reporting year without one vessel, truck or route changing. Sustainability teams setting 2027 logistics targets need to know which kind of movement their numbers show. An invoice can name the shipment, carrier, weight and destination while saying nothing about how much fuel that particular load burned.

Every freight carbon figure is a calculation layered on top of those shipment records. Smart Freight Centre is the nonprofit that maintains the Global Logistics Emissions Council (GLEC) Framework. It relies on the International Organization for Standardization (ISO) 14083:2023 definition of primary data, which is a value obtained from direct measurement of a process or activity. Its guidance on primary data in Scope 3 accounting acknowledges that shippers and logistics providers often work from secondary data or estimates. Carriers usually hold the energy and operating records, and even measured fuel has to be converted with emission factors before it becomes a greenhouse gas figure.

Ocean Freight Just Showed How Big a Method Effect Can Be

Clean Cargo, the container shipping initiative run by Smart Freight Centre, published a methodology update on August 6, 2026. According to the organization’s announcement, emissions are now calculated from vessel-level activity that carriers report in twenty-foot equivalent unit kilometers (TEU-km). That replaces a standardized 70% vessel utilization assumption. The organization said the change improves accuracy while creating a break in comparability between 2024 and 2025 intensity values.

The practical effect lands in lane-level reporting. A 2025 trade lane intensity that looks worse than the prior year may reflect ships that sailed with less cargo than the old assumption implied. A better-looking figure can come from the reverse. Neither result says much about carrier performance until the method effect is pulled apart from the operating change. Teams already weighing when a recalculated baseline helps or hurts reported progress will face the same judgment with ocean data in this cycle.

Shared Loads Make Every Footprint an Allocation Choice

Most freight moves on shared assets. A container ship, a linehaul truck or a cargo aircraft carries goods for many customers, and the emissions from each trip have to be divided among them. The share assigned to any one shipper depends on how much total cargo sits in the denominator. Change that denominator and the assigned footprint moves, even when fuel burn stays the same.

Utilization is that denominator in practice. Swapping an assumed load factor for reported cargo activity can make the calculation more faithful to what actually sailed, yet it also shifts the apparent trend. Real operations add further complications, since cargo weight, loading patterns, weather and fuel use all interact. Reporting teams need a written explanation of the method effect before anyone presents the change as a carrier getting cleaner or dirtier.

Carrier Data Is Not Always Shipment Data

Trucking offers a second example. The U.S. Environmental Protection Agency (EPA) publishes technical documentation for its 2024 SmartWay Online Shipper Tool, covering data year 2023. It explains that truck carrier values in grams per mile and grams per ton-mile represent the midpoints of performance bins. The bin midpoint serves as the emission factor for every fleet in that range, so the value describes a SmartWay category and not the exact performance of a given carrier. The tool then multiplies those factors by ton-miles or miles and sums the results.

Those mechanics belong to that tool version, and the EPA keeps shipper tool resources updated by reporting year, so they should not be read as a description of every calculator on the market. They still illustrate a common pattern. Two carriers sharing a bin look identical in a shipper’s inventory even if one runs a noticeably more efficient fleet. A fleet-level factor works well for an annual inventory but offers thin evidence for judging a single route investment.

The useful question for any freight number is what it represents. It could describe one movement, a carrier’s fleet, a trade lane or an industry average, and each supports a different kind of comparison. The answer often depends on how ready carriers are to share operating records, a gap that mirrors the broader supplier readiness problem in Scope 3 data.

Matching the Data to the Target

Modeled and average figures still have a role. They fill gaps where operating records are unavailable, and they help test future scenarios. Smart Freight Centre’s guidance advises companies to request primary data where possible, build systems for reliable exchange with carriers and document the reasons whenever they fall back on secondary inputs.

Before attaching performance targets to freight, a sustainability team can settle the reporting boundary, the data period, the treatment of empty running and the allocation method. With those fixed, the team can ask carriers for enough detail to separate changes in shipment volume, routing and mode from changes in carrier efficiency and calculation assumptions. The same questions sit underneath the longer-running debate over how shipping emissions are counted.

Effort can follow materiality. A high-volume lane, or a contract that carries a sustainability premium, may justify the work of collecting more representative operating evidence. Smaller lanes can reasonably stay on estimates as long as the inventory labels them clearly.

Ocean Accounting Is Moving Toward Measured Activity

Clean Cargo’s own methodology roadmap shows the direction of travel. It lists fuel type alignment for 2025, actual cargo carried and engine-specific fuel consumption for 2026, and tonne-kilometer reporting alongside TEU-km starting in 2027. The method is also shifting from trade lane averages to port-pair figures based on distances from vessel tracking.

Each step should bring reported numbers closer to what physically moved, and each one opens the door to another discontinuity in multiyear trends. Companies that annotate method changes in their inventories year by year will find it easier to show auditors which movements were operational. The 2027 tonne-kilometer addition is the next point where ocean intensities may need that annotation.