Flight methodologies
Flight methods differ most in two settings: whether they count producing the fuel (well-to-wheel) and whether they add non-CO₂ effects. Results are only comparable when both match.
| Methodology | Best for | Data used | Energy scope | Non-CO₂ effects | Cabin class |
|---|---|---|---|---|---|
| DEFRAUK Government (DESNZ) | UK-based company reporting | Averages by flight type and cabin | WTW, TTW optional | Included, optional | Yes |
| ADEMEFrench Ministry for Ecological Transition, with ADEME | Reporting that follows French official values | Averages by distance and aircraft size | WTW | Not included | No |
| Base EmpreinteADEME | Carbon accounting in France with ADEME factors | Averages by distance and aircraft size | WTW | Included, optional | No |
| CO₂-emissiefactorenCO2emissiefactoren.nl | Reporting in the Netherlands | Averages by distance band and cabin | WTW, TTW optional | Included, optional | Yes |
| GATE4Advito (BCD Travel) | Travel programmes that report with Advito or BCD Travel | Provider model with flight details | Set by Advito | Included (Advito) | Yes |
| ICAOInternational Civil Aviation Organization (ICAO) | General estimates of combustion CO₂ | ICAO method, without the ICEC dataset | TTW, CO₂ only | Not included | Economy or business |
| Travel Impact ModelGoogle | Comparing flights and reporting with flight-level detail | Flight-specific model | WTW, TTW optional | Separate contrail rating | Yes |
| TU ChalmersChalmers University of Technology and University of Gothenburg | Footprints that include non-CO₂ effects | Averages by cabin and service type | WTW | Always included | Yes |
| US EPAUS Environmental Protection Agency (EPA) | US corporate GHG inventories | Three distance bands | TTW | Not included | No |