How Logistics Emissions Are Calculated — A Plain-Language Guide
The basic idea
Calculating the carbon footprint of moving goods comes down to one simple question: how much effort did it take to move this cargo, and how dirty was the energy used to do it?
You multiply the effort by the pollution factor, and you get a CO₂ number.
That’s it at the core. The complexity comes from making it fair, consistent, and comparable across different vehicles, routes, and companies.
What you need to start
Three ingredients:
| Ingredient | What it means | Example |
|---|---|---|
| Cargo weight | How heavy are the goods? | 5 tonnes of furniture |
| Distance | How far do they travel? | 800 kilometres by road |
| Energy type | What vehicle moves them, and what fuel does it use? | A diesel rigid truck |
Step 1: Turn weight × distance into one number
Logistics uses a combined unit called a tonne-kilometre. It captures both how heavy the cargo is and how far it travels in a single figure.
Move 2 tonnes of goods for 100 km = 200 tonne-kilometres
In other words, think of it like a taxi meter - except instead of measuring time and distance, it measures weight and distance. The heavier your cargo and the longer the trip, the higher the reading on the meter.
Step 2: Apply the “pollution factor”
Now you multiply the tonne-kilometres by an emission intensity factor — a standard number that tells you how much CO₂ a particular vehicle type produces per tonne-kilometre.
200 tkm × 0.062 kgCO₂e per tkm = 12.4 kg of CO₂
In practice, these intensity factors are published in the GLEC Framework and are different for every transport mode:
| Transport mode | Approximate intensity | Why the difference? |
|---|---|---|
| Large truck (HGV) | ~0.06–0.09 kgCO₂e/tkm | Road friction, diesel engine |
| Container ship | ~0.008–0.015 kgCO₂e/tkm | Very efficient per tonne at scale |
| Freight aircraft | ~0.5–0.8 kgCO₂e/tkm | Jet fuel, high altitude |
| Electric rail | ~0.002–0.01 kgCO₂e/tkm | Grid electricity, low friction |
As a result, a ship is roughly 5–10× more efficient than a truck per tonne-kilometre, which is why sea freight has a much lower carbon footprint per unit of cargo despite travelling much further.
Step 3: Handle multi-modal journeys
Most international shipments use several different vehicles. A factory in Germany might ship goods:
- By truck → to a port in Hamburg
- By container ship → to a port in Singapore
- By truck again → to the customer’s warehouse
You don’t try to calculate the whole journey at once. Instead, you break it into legs — one calculation per vehicle, per mode. Then add them all up.
| Leg | Distance | Mode | CO₂ |
|---|---|---|---|
| Hamburg factory → port | 80 km | HGV truck | 4.2 kg |
| Hamburg → Singapore | 19,300 km | Container ship | 12.6 kg |
| Singapore port → warehouse | 45 km | Light truck | 1.8 kg |
| Total | 18.6 kg |
Consequently, this is exactly what ISO 14083 standardises — the rules for breaking a journey into consistent, comparable legs and calculating each one the same way, regardless of who did the calculation.
Step 4: Share emissions fairly between customers
Here’s the tricky part. A truck carrying goods from a warehouse doesn’t carry goods for just one company — it carries pallets for ten different customers at once.
So whose CO₂ is it?
The answer: you split it proportionally, based on weight.
In practice, think of it like splitting a taxi fare. If five people share a cab, you don’t charge the whole fare to one person. You split it based on how much space each person took up and how far they stayed in the cab.
How the split works in numbers
For freight, the same principle applies:
- Your 2-tonne pallet on a 20-tonne truck = you’re responsible for 10% of that truck’s emissions on that leg
- If your pallet also travels twice as far as another customer’s goods, you bear more of the total
Operators call this process allocation, and it is one of the most regulated parts of ISO 14083 — because getting it wrong means one company overpays in carbon terms while another underpays.
What “Well-to-Wheel” means
When a truck burns diesel, you see exhaust coming from the tailpipe. That’s the obvious part. But before the diesel reached the engine, it had to be:
- Extracted from the ground (drilling)
- Refined into diesel
- Transported to the fuel station
- Pumped into the truck’s tank
Together, all of those steps also produce CO₂ — typically an additional 15–25% on top of what the tailpipe produces.
Well-to-Wheel means counting both parts:
Well → Tank + Tank → Wheel
(fuel production) (vehicle operation)
= FULL carbon footprintTherefore, ISO 14083 and the GLEC Framework require both to be included. A calculation that only counts the tailpipe understates the true impact by roughly 20%.
Rough estimates vs. precise calculations
Not all emissions calculations are equally trustworthy. In practice, there are two approaches:
Rough estimate (default data)
Uses industry-average figures. Like guessing your monthly grocery bill based on what a typical household spends.
- Fast and cheap to produce
- Useful when you have no other data
- Tends to be conservative (higher than actual) to avoid underreporting
- Will not pass assurance review under CSRD
Precise calculation (primary data)
Uses actual data from the specific shipment — real fuel receipts, GPS-tracked distance, verified cargo weight, measured load factors.
- Requires data from the Carrier
- More work to collect
- More accurate to the actual trip
- Required for CSRD limited and Reasonable Assurance
Specifically, the GLEC Framework scores data quality on a 4-tier scale. Tier 1 is the most precise measured (glossary: Primary Data; Tier 4 is the roughest (industry-average defaults). Companies filing CSRD disclosures are expected to improve their tier over time.
Why consistency matters more than precision alone
Two carriers could calculate emissions for the same route and arrive at numbers that differ by 75%. Both could be using legitimate methods — just different ones.
Importantly, this is the problem ISO 14083 solves. By standardising:
- Which emission sources to include
- How to measure distance
- Which allocation method to use
- Whether to apply Well-to-Wheel or just tailpipe figures
As a result, it creates a common language. When every company uses the same rules, the numbers become comparable — between carriers, between reporting periods, and between companies in a supply chain.
That comparability is what makes freight emissions data useful for CSRD reporting, procurement decisions, and external assurance.
The CO2Path approach
CO2Path applies this process at the shipment level. It breaks each shipment into legs following the ISO 14083 structure, calculates each leg using the correct emission intensity factor for that mode and vehicle type, computes the full Well-to-Wheel figure, and writes the result to a blockchain-secured record that is traceable back to the source data.
In other words, the output is not just a number — it is a verifiable, auditable record of how that number was reached.
Frequently asked questions
Logistics emissions are calculated by multiplying the cargo weight (in tonnes) by the transport distance (in kilometres) to get tonne-kilometres, then multiplying by an emission intensity factor for the vehicle type. For multi-modal shipments, you calculate each leg separately and add the results together.
A tonne-kilometre is the standard unit for measuring freight transport work. It equals one tonne of cargo transported one kilometre. Moving 5 tonnes for 200 km equals 1,000 tonne-kilometres. As a result, this unit lets the carbon footprint of a container ship and a delivery van be compared on equal terms.
Emission intensity factors measure how much CO₂e a particular vehicle type produces per tonne-kilometre. Published in the GLEC Framework, they vary widely by mode. For example, a large diesel truck produces approximately 0.06–0.09 kgCO₂e/tkm, a container ship 0.008–0.015 kgCO₂e/tkm, and a freight aircraft 0.5–0.8 kgCO₂e/tkm.
Well-to-Wheel (WTW) means counting the full carbon cost of a fuel — from extraction and refining (Well-to-Tank) through to actual combustion in the engine (Tank-to-Wheel). ISO 14083 requires WTW for all calculations. As a result, a WTW figure is typically 15–25% higher than tailpipe-only figures.
Allocation is the process of fairly dividing a vehicle’s emissions among multiple customers when it carries co-loaded cargo. Specifically, ISO 14083 divides emissions in proportion to each customer’s cargo weight and the distance it travels — similar to splitting a shared taxi fare based on passenger numbers and journey length.
Primary data comes from actual measurements of a specific shipment — real fuel receipts, GPS distances, verified cargo weights. In contrast, secondary data uses published industry averages. Primary data is more accurate and required for CSRD reasonable assurance; secondary (default) data from the GLEC Framework is intentionally conservative to prevent underreporting.