Reference
The words, defined.
Emissions accounting is full of terms that sound precise and mean different things to different vendors. These are the definitions Farleda applies — including the ones that mark a limit rather than a feature.
Editorial review
Emissions accounting
How a journey becomes a number.
- Avoided emissions
The difference between an activity that took place and a plausible reference scenario. Farleda currently shows modelled differences between planned journeys; these do not establish actual avoided emissions.
A planning comparison is not a carbon credit and must not be presented as an achieved reduction.
Methodology- Counterfactualreference case
The alternative journey an avoided-emissions figure is measured against — for Farleda, normally the flight between the same city pair, calculated with a published flight factor. Naming the counterfactual is what makes the figure checkable: change the reference, change the result.
A counterfactual is a modelled assumption about what would have happened. It is disclosed rather than presented as an observation.
- CO₂ecarbon dioxide equivalent
A single unit that expresses several greenhouse gases as the amount of CO₂ with the same warming effect. It is what allows a train leg and a flight leg to be compared with one number.
- Emission factor
The published quantity of CO₂e per unit of activity for a mode of travel — for example grams of CO₂e per passenger-kilometre. Farleda uses UK DESNZ tables as disclosed planning proxies, plus its own model for electric rail.
Data inventory- Activity unit
What a factor is multiplied by. Public transport is calculated per passenger-kilometre; cars are calculated per vehicle-kilometre and then divided across the travellers in the vehicle.
- g CO₂e/pkmgrams per passenger-kilometre
The workhorse unit of this field: grams of CO₂e for moving one passenger one kilometre. Farleda's default for the electric-rail model is 28 g CO₂e/pkm, replaced by country context where that is available.
- Load factoroccupancy
The share of occupied seats or used capacity. It affects per-person figures alongside vehicle type, propulsion, energy source and operating conditions.
Farleda does not measure occupancy on a particular train. Ranges are model scenarios, not statistical confidence intervals or measurement uncertainties.
- Radiative forcingRF uplift
The additional warming effect of aviation emissions released at altitude, beyond the CO₂ itself. Farleda's flight factors include the DESNZ radiative-forcing uplift, so flights are not flattered by leaving it out.
- Well-to-tankWTT
Emissions from producing and supplying energy before it is used. The DESNZ workbook reports WTT factors separately.
Farleda does not currently add WTT rows to the DESNZ operational factors. Electricity sources may have different boundaries, so comparisons are not a uniform full lifecycle assessment.
- Grid carbon intensity
The CO₂e emitted per kilowatt-hour of electricity in a given country or zone, in g CO₂e/kWh. Electric-rail emissions depend on it, which is why a train in Sweden and the same train in Poland are not the same journey.
Grid factors- Energy conversion assumption
Farleda converts grid intensity into rail intensity with 0.09 kWh per passenger-kilometre. This is a product modelling assumption applied consistently, not a measured energy value for every train.
- Great-circle distance
The shortest path between two points on a sphere — used to approximate a flight between airport coordinates when routed geometry is unavailable, with disclosed detour factors applied.
It is an approximation between airports, not the track an aircraft actually flies. Legs calculated this way carry that label.
- Modal shift
A change from one transport mode to another. Measuring modal shift in a pilot requires evidence of the original choice and actual behaviour.
Selecting rail in a planner alone establishes neither completed travel nor modal shift.
For partners
Records and verification
What Farleda issues, and what checking it establishes.
- Trip Carbon Passport
A signed calculation record for a saved journey plan: route, estimated emissions, comparison scenario and methodology version. Its signature can establish integrity through Farleda; it does not confirm completed travel.
Verify a passport- Signed calculation record
The current scope of a Passport: it documents a plan and its calculation. The signature covers the recorded content; it does not independently validate source data, travel or environmental outcomes.
It is not a certificate, not an offset, not a credit and not an approval by any authority.
- HMAC-SHA256
A keyed message authentication code used to protect the canonical Passport content. Changes to the authenticated content cause verification to fail.
Issuance and verification use a shared server-side secret. Third parties check through Farleda; this is not an independently verifiable public-key signature.
- Verify endpoint
A prepared public interface for Passport format, integrity and consistency checks. Once released, it requires no application account; actual access follows the API release status.
Verification page- Publicly checkable
Once the API is released, a Passport can be checked without an account through Farleda’s service. The result concerns the signed calculation record.
Public access does not mean independent validation of journey data, the method or environmental impact.
- Methodology version
The version identifier of the calculation rules in force when a record was signed. It travels inside the passport, so a record made under older rules stays interpretable after the methodology changes.
Methodology
Data and sources
Where the inputs come from.
- DESNZ conversion factors
The UK government's annually published greenhouse-gas conversion factors, widely used as a planning reference across Europe. Farleda uses them as disclosed proxies, with the source and year shown per figure.
Data inventory- Transitous / MOTIS
A community-operated timetable-routing service. Coverage, freshness and quality depend on the integrated feeds; the actual operating day needs checking.
- OpenStreetMap servicesNominatim · Overpass · OSRM
Services for place lookup, points of interest and road geometry. Depending on the feature, requests contain place names, coordinates, parameters and technical metadata.
Subprocessors- Open data
Data licensed for open use and redistribution. Attribution or share-alike conditions depend on the dataset. Farleda’s prepared public JSON responses carry a CC-BY-4.0 label; third-party rights still apply.
API documentation
Governance and commercial terms
The words that show up in procurement, not in the product.
- Carbon offset
A purchased claim that emissions elsewhere were reduced or removed to compensate for one's own. A recognised, and frequently criticised, market instrument.
Farleda sells none, issues none and holds none. This term appears on the site only to state what a passport is not.
- EmpCo Directive (EU) 2024/825
An EU directive strengthening consumer information, including rules on environmental claims. It requires national implementing measures to apply from 27 September 2026. Whether a particular claim is permitted depends on its content, evidence and applicable law.
Directive text on EUR-Lex- Data-processing agreementDPA
The contract under GDPR Art. 28 that governs a processor handling personal data on a controller's behalf. Before a pilot, the parties determine their data-protection roles. A DPA is signed before processing where Farleda handles personal data on the partner’s behalf; it is not automatically required for every pilot.
- Subprocessor
A provider engaged by a processor to carry out further processing on its behalf. Farleda’s provider inventory distinguishes services and scope; roles and change procedures depend on the processing and contract.
Subprocessor list- Private preview
Farleda's current non-public development phase. Preview access may be released individually; this does not imply existing customers or a public service. The open beta is planned for 31 October–31 December 2026. Production operation is targeted for early 2027, subject to release approval.
System status
Use claims precisely
Language for communication that can be substantiated.
“Certificate”
A passport is a signed record, not a certificate. Nothing is certified, and no certifying body is involved.
“Independently verified”
Verification runs against Farleda's own key. The honest phrasing is “publicly checkable — by anyone, without an account”.
“Carbon neutral”, “climate positive”
An emissions estimate does not establish that a journey is climate- or environmentally neutral. Public environmental claims require specific evidence and review of the actual wording.
“You saved the planet”
A modelled difference against a stated alternative is not demonstrated environmental impact. Planned and completed journeys remain distinct.
Terms are defined once here and used consistently across the site. The full calculation rules live in the methodology, the source-by-source inventory in the data pages, and the security and processing vocabulary on the security and subprocessor pages.
