Question 1

Is ICAO CEC v13.1 the same as ISO 14083?

Accepted Answer

They are complementary, not identical. ISO 14083:2023 is the international framework standard for calculating GHG emissions across transport chains — it defines the allocation methodology and reporting requirements. ICAO CEC v13.1 is the aviation-specific data source: aircraft fuel burn tables, load factors, and seat-class allocation coefficients. In practice, ICAO CEC provides the inputs that ISO 14083 requires for the aviation segment of a transport chain calculation.

Question 2

Which standard does the GHG Protocol recommend for Scope 3 Category 6?

Accepted Answer

The GHG Protocol Scope 3 Calculation Guidance (Category 6: Business Travel) recommends using spend-based, distance-based, or activity-based methods. For the activity-based method — which is the most accurate — it points to the ICAO Carbon Emissions Calculator as the preferred aviation emission factor source. This is what our API implements: ICAO CEC v13.1 applied per trip segment.

Question 3

Should I report CO₂ only or CO₂e including RFI?

Accepted Answer

The GHG Protocol Scope 3 Standard recommends CO₂-only (without RFI) for Category 6 corporate reporting, because the scientific uncertainty around non-CO₂ climate effects is higher. However, CDP (C6 questionnaire) and SBTi increasingly ask companies to disclose both. Our API returns both co2_kg (CO₂ only) and co2_with_rfi_kg (CO₂ × RFI factor 1.9) in every response — you choose which to use per disclosure framework.

Question 4

What is the GLEC Framework and does this API cover it?

Accepted Answer

The GLEC (Global Logistics Emissions Council) Framework is a methodology for calculating logistics and freight transport emissions — primarily used by supply chain and logistics companies. It references ISO 14083 for the underlying calculation approach. Our API covers the passenger aviation segment specifically (business travel, flight booking platforms). Freight/cargo emission calculations are not currently in scope.

Question 5

What is CORSIA and how does it relate?

Accepted Answer

CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation) is ICAO's mechanism for airlines to offset CO₂ growth above 2019 baseline levels. Airlines — not corporations — use CORSIA. Our API uses the same ICAO CEC v13.1 methodology that underpins CORSIA airline reporting, which is why the numbers are consistent with what airlines report. For corporate Scope 3 Category 6, you reference GHG Protocol rather than CORSIA directly.

Question 6

Does the confidence_score in the response indicate methodology quality?

Accepted Answer

No — confidence_score indicates data quality for that specific calculation: 0.9+ means exact aircraft type data was used, below 0.7 means a fleet-average fallback applies. The methodology (ICAO CEC v13.1) is the same regardless. For disclosures, you can flag low-confidence trips as 'estimated' in your methodology note, which is explicitly permitted by the GHG Protocol.

The right methodology.
The right numbers.

Which framework asks for what

API response → disclosure field

ICAO CEC vs. alternatives

GHG Protocol & ISO 14083 — Common Questions

Start with the right methodology.

The right methodology. The right numbers.