How Logistics Emissions Are Measured

For most companies, logistics represents one of the largest sources of Scope 3 emissions. Yet when asked exactly how transport emissions are measured, many sustainability managers struggle to explain the methodologies behind the numbers in their carbon reports.

The measurement of logistics emissions isn't intuitive. Unlike factory emissions where you can install monitors on smokestacks, transport emissions happen across thousands of kilometers involving vehicles, vessels, and aircraft that companies don't own or directly control. The calculation requires combining activity data, emission factors, and allocation methodologies in ways specific to each transport mode.

Understanding these measurement approaches is becoming critical as regulatory frameworks like CBAM and BRSR demand greater accuracy in supply chain emissions reporting. Companies that grasp how logistics emissions are calculated can improve data quality, identify reduction opportunities, and satisfy verification requirements.

The Fundamental Measurement Principle

All transport emission calculations follow a basic formula, regardless of mode:

Emissions = Activity Data × Emission Factor

Activity data represents the amount of transport performed, typically measured in tonne-kilometers (weight of goods multiplied by distance traveled). Emission factor represents the CO2 emitted per unit of activity, expressed in grams or kilograms of CO2 per tonne-kilometer.

These emission factors are typically derived from globally recognized datasets such as IPCC, DEFRA, and IEA, which provide standardized values across fuels, transport modes, and geographies.

Methodological Frameworks and Standards

Several international standards provide structured approaches to transport emissions measurement.

The GHG Protocol distinguishes between Scope 1 (owned/controlled vehicles), Scope 2 (purchased electricity), and Scope 3 (upstream and downstream logistics). Most corporate logistics emissions fall under Scope 3 Category 4 (upstream transportation and distribution) and Category 9 (downstream transportation and distribution).

The Global Logistics Emissions Council (GLEC) Framework, published in 2016 and updated regularly, provides detailed methodologies specifically for logistics emissions. GLEC is recognized by the GHG Protocol as an authorized guidance for transport and logistics.

ISO 14083:2023, published in March 2023, establishes principles and requirements for quantification and reporting of greenhouse gas emissions from transport operations. This standard is becoming the global reference for transport carbon accounting.

These frameworks converge on similar calculation approaches but differ in specific requirements for data quality, allocation methods, and reporting formats.

Road freight, including trucks, vans, and light commercial vehicles, uses several calculation approaches depending on data availability.

Fuel-based calculation (most accurate):

When actual fuel consumption data is available, emissions are calculated directly from fuel quantity multiplied by fuel emission factors Diesel combustion emits approximately 2.68 kg CO2 per liter, based on widely used emission factors published by DEFRA and aligned with IPCC guidelines. A truck consuming 300 liters to transport goods emits about 804 kg CO2.

This method requires access to actual fuel consumption data from logistics providers, which larger carriers can often provide through telematics systems but smaller operators may lack.

Distance-based calculation:

When fuel data is unavailable, emissions are estimated using distance traveled, vehicle type, load factor, and standard emission factors. The GLEC Framework provides emission factors for different truck types:

• Rigid trucks (≤7.5 tonnes): approximately 200-400 g CO2 per tonne-km

• Rigid trucks (7.5-17 tonnes): approximately 100-200 g CO2 per tonne-km

• Articulated trucks (>17 tonnes): approximately 60-100 g CO2 per tonne-km

These factors vary based on vehicle age, fuel type (diesel, CNG, electric), load factor (percentage of capacity utilized), and terrain. alues vary significantly by geography, vehicle standard, and fuel type (e.g., Euro VI vs older fleets).

Spend-based calculation:

When operational data is unavailable, emissions can be estimated from transportation spending multiplied by economic emission factors (emissions per currency unit spent). This approach is permitted under GHG Protocol but produces the lowest quality estimates.

Load factor considerations:

A critical variable in road transport emissions is load factor - the percentage of vehicle capacity actually used. A truck running half-empty effectively doubles the emissions per tonne of goods transported. GLEC requires allocation based on actual load factors rather than assuming full capacity.

Rail Transport Measurement

Rail freight emissions vary dramatically based on electrification, fuel type, and operational efficiency.

Electrified rail:

For electric rail, grid emission factors are typically sourced from national inventories and global datasets such as the IEA and IPCC. in the region where the train operates. European rail networks powered primarily by renewables may emit 10-20 g CO2 per tonne-km, while networks using coal-heavy grids may emit 50-80 g CO2 per tonne-km.

The calculation requires:

• Energy consumption (kWh per tonne-km)

• Grid emission factor for the specific geography (g CO2 per kWh)

Diesel rail:

Diesel locomotives emit approximately 20-40 g CO2 per tonne-km depending on efficiency, load, and terrain. The calculation uses:

• Fuel consumption (liters diesel per tonne-km)

• Diesel emission factor (2.68 kg CO2 per liter)

Intermodal considerations:

Rail freight often involves intermodal operations where goods transfer between trucks and trains. Measuring complete journey emissions requires combining different modes' emission factors for each leg, plus emissions from loading/unloading operations.

Sea Freight Measurement

Maritime shipping represents the lowest carbon intensity per tonne-km among conventional transport modes but involves complex measurement challenges.

Vessel-specific calculation:

The most accurate approach uses actual fuel consumption from specific vessels. Heavy fuel oil (HFO), the most common marine fuel, emits approximately 3.11 kg CO2 per kg of fuel, with emission factors aligned to guidance from the IMO and IPCC.

Leading shipping lines can provide vessel-specific fuel consumption data for specific voyages, enabling accurate emission allocation to individual shipments.

Distance and vessel-type calculation:

When vessel-specific data is unavailable, emissions are estimated using:

• Container ships: approximately 5-20 g CO2 per tonne-km (varies enormously by vessel size)

• Bulk carriers: approximately 3-10 g CO2 per tonne-km

• General cargo ships: approximately 10-30 g CO2 per tonne-km

The GLEC Framework provides detailed emission factors categorized by vessel type and size. Larger vessels generally have lower emissions per tonne-km due to economies of scale.

TEU allocation for containers:

Container shipping uses Twenty-foot Equivalent Units (TEUs) as the standard measure. Allocating vessel emissions to individual shipments requires:

• Total voyage fuel consumption

• Number of TEUs transported

• Weight factor if containers have varying densities

Trade lane and routing considerations:

Emissions per tonne-km vary by route due to factors including vessel speed (slower steaming reduces fuel consumption), weather conditions, port congestion, and routing efficiency. The same goods shipped from Shanghai to Rotterdam via Suez Canal versus Cape of Good Hope will have different carbon footprints.

Air transport has by far the highest emission intensity of any freight mode, typically 500-1,500 g CO2 per tonne-km depending on aircraft type and route.

Belly freight vs. dedicated cargo:

Commercial passenger flights carry freight in cargo holds ("belly freight") alongside passengers. Dedicated cargo aircraft carry only freight. Emission allocation differs significantly:

For belly freight, emissions must be allocated between passengers and cargo, typically based on weight or revenue. ISO 14083 provides allocation methodologies.

For dedicated cargo flights, all aircraft emissions are allocated to freight only.

Distance-based calculation:

The GLEC Framework provides emission factors by aircraft type and haul distance. These values are derived from global aviation datasets and aligned with methodologies from the IPCC and international energy datasets such as the IEA:

• Short haul (<1,000 km): approximately 1,000-1,500 g CO2 per tonne-km

• Medium haul (1,000-3,000 km): approximately 600-800 g CO2 per tonne-km

• Long haul (>3,000 km): approximately 500-600 g CO2 per tonne-km

Longer flights are more efficient per kilometer due to cruise efficiency, though total emissions are higher.

Actual flight data:

Some air cargo carriers provide shipment-specific emissions calculated from actual flight fuel consumption, aircraft type, load factors, and routing. This represents the highest quality air freight emission data.

Radiative forcing and non-CO2 effects:

Aviation emissions have climate impacts beyond CO2, including water vapor, nitrogen oxides, and contrail formation. Some methodologies apply radiative forcing multipliers of 1.5-3× to account for these effects, though this remains debated in carbon accounting standards.

Data Quality Tiers and Verification

ISO 14083 and GLEC Framework both establish data quality hierarchies:

Primary data includes actual fuel consumption, specific vehicle/vessel details, and real routing information. This provides the highest accuracy.

Secondary data uses industry average emission factors specific to vehicle type, region, and operational characteristics. This provides moderate accuracy.

Tertiary data applies generic emission factors or spend-based calculations. This provides the lowest accuracy but may be the only option for small shipments or when carriers don't provide operational data.

For CBAM and increasingly for BRSR, verification requirements favor primary or secondary data over tertiary estimates.

Practical Measurement Challenges

Companies implementing logistics emissions measurement face several common challenges:

Carrier data availability: Many logistics providers, especially smaller operators, cannot provide detailed fuel consumption or activity data required for accurate calculations.

Multimodal journeys: Goods often move via multiple transport modes (truck to rail to ship to truck). Measuring complete journey emissions requires combining data from multiple sources.

Allocation complexity: When vehicles or vessels carry goods for multiple customers, allocating total emissions to specific shipments requires load factors, routing, and sometimes commercial allocation agreements.

Empty return journeys: Trucks or containers returning empty to origin still emit, and these emissions should be allocated to the goods that necessitated the journey.

Scope boundaries: Determining which logistics activities to include (last-mile delivery, warehousing, product returns) requires clear boundary definitions.

Moving Toward Accuracy

Improving logistics emissions measurement accuracy requires:

Engaging carriers on data provision: Requesting fuel consumption data, load factors, and routing information from major logistics providers.

Implementing technology platforms: Digital tools that integrate with carrier systems, apply appropriate emission factors, and manage allocation calculations.

Building verification readiness: Documenting calculation methodologies, emission factor sources, and data quality assessments to satisfy audit requirements.

Robust logistics emissions measurement relies on standardized methodologies and emission factors sourced from globally recognized bodies such as the IPCC, DEFRA, IEA, and IMO. As regulatory frameworks tighten verification requirements, companies measuring logistics emissions using robust methodologies aligned with GLEC, ISO 14083, and GHG Protocol standards will satisfy compliance needs while enabling meaningful decarbonization strategies.

Need help measuring logistics emissions accurately across your supply chain? WOCE provides comprehensive carbon accounting solutions that apply appropriate methodologies for each mode, integrate with enterprise systems, and deliver verification-ready reporting for CBAM, BRSR, and investor disclosure. Contact us at contact@worldofcirculareconomy.com to build your logistics measurement capability.