From shipment data to trusted emissions records: how CO2Path works
Solving the methodology problem is only the first step. Running freight emissions calculation at scale is the operational challenge that follows. It means producing compliant records for every shipment, in a format that carriers, clients, and assurance teams can use. However, a logistics operator that understands ISO 14083 does not automatically know how to do that.
This is where the platform layer becomes necessary. In practice, knowing the standard and operating under it are two different things. Most logistics operators currently sit in that gap. Therefore, this article explains how CO2Path's freight emissions calculation turns raw shipment data into ISO 14083-compliant records, and why each step matters.
The four steps
Step 1: Shipment data input
First, the starting point is the shipment record: transport mode, vehicle or vessel type, fuel type or energy carrier, distance, and payload. For each data input, CO2Path applies a data quality assessment aligned with the ISO 14083 / GLEC Framework hierarchy. CO2Path uses primary data when available. Where primary data is unavailable, the platform applies GLEC default values and flags the data quality tier in the output. As a result, every calculation carries transparent information about how accurate its inputs are. The methodology article explains the GLEC data quality tier system in full, including what Tier 1 versus Tier 4 means for CSRD assurance.
Step 2: ISO 14083-compliant freight emissions calculation
Specifically, CO2Path applies mode-specific emission factors across all five transport modes: road, rail, sea, inland waterway, and air. For each leg, CO2Path first multiplies cargo mass by distance to produce transport activity in tonne-kilometres (tkm). It then applies the mode-specific emission factor to that tkm figure, giving a kg CO₂e result per leg. For co-loaded shipments, it supports mass-based, volume-based, and TEU-based (Twenty-foot Equivalent Unit) allocation. It also calculates both Tank-to-Wheel (TTW) and Well-to-Wheel (WTW) in parallel. For multi-modal shipments, CO2Path calculates each leg separately and assembles the results into a complete transport chain. Crucially, ISO 14083 requires every segment. For example, a pre-carriage truck leg, a rail segment, and last-mile delivery each generate a separate calculation, not a blended average.
Step 3: Blockchain-secured record creation
Once CO2Path completes the calculation, it writes the result as a transaction on the public Ethereum blockchain. Specifically, the on-chain record contains the actual data: input values, methodology version, emission factor source, and calculation parameters, not just a summary hash. Nobody can alter or delete a confirmed Ethereum transaction. Additionally, any third party can inspect the record directly using the transaction hash, without going through CO2Path or any intermediary. Each report also has a stable, publicly accessible URL, resolvable via QR code, giving auditors, shippers, and regulators a direct link. In practice, this transforms an emissions figure into an auditable claim, verifiable externally, not just asserted by the operator.
Step 4: Structured output for reporting and audits
Finally, the output is a set of shipment-level emissions records, each containing:
- Emission result: kg CO₂e, broken down by TTW and WTW
- Methodology reference: ISO 14083 version, GLEC Framework version, emission factor database
- Data quality tier: primary data, secondary data, or default values, by input
- Allocation basis: which rule was applied and why
- Blockchain reference: the Ethereum transaction hash, publicly verifiable on-chain
- Report URL: a stable, publicly accessible link to the full record, resolvable via QR code
CO2Path also aggregates shipment-level records into periodic summaries (monthly or annual) for direct use in Scope 3 Category 4 disclosures.
Why this matters now
CSRD assurance requirements are tightening. The CSRD obligations article sets out the full regulatory trajectory from limited to reasonable assurance. This trajectory holds even after the Omnibus simplification cut mandatory ESRS datapoints by over 60%: Scope 3 GHG disclosure, freight included, stayed in scope. The reporting form got shorter; the underlying evidence bar did not. Specifically, that trajectory has one clear implication for data infrastructure. Documentation requirements arriving in two to three years need underlying records built today. Consequently, companies running ISO 14083-compliant calculation now build the evidence base they will need under audit, rather than retrofitting under pressure. Furthermore, early investment in correct infrastructure avoids a far more expensive reconstruction when assurance reviewers trace individual shipment records to source.
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Frequently asked questions
For each shipment leg: transport mode, vehicle or vessel type, fuel type or energy carrier, cargo mass, and route distance. Where primary data is not available, CO2Path applies GLEC Framework default values and clearly labels the data quality tier in the output.
CO2Path calculates each transport leg separately using mode-specific emission factors. It then assembles all legs into a complete transport chain result, in line with ISO 14083's requirement to include every segment.
Every record includes: the methodology applied (ISO 14083 / GLEC version), the emission factor source, the data quality tier, the allocation method used, and a blockchain reference confirming the record is unchanged. Together, these make the record auditable by third parties without relying on internal attestation.
CO2Path applies allocation based on cargo mass and distance for co-loaded shipments, as ISO 14083 requires. When the full vehicle payload is unavailable, CO2Path applies GLEC default load factors and flags the tier accordingly.