Flight: DEFRA πŸ‡¬πŸ‡§

πŸ’‘ High-Level Description:

The Department for Environment, Food, and Rural Affairs (DEFRA) of the United Kingdom plays a key role in shaping environmental policies and approaches to carbon reduction. As part of its sustainability initiatives, DEFRA has developed a carbon calculation methodology specifically for the flight passenger sector, providing a standardized and credible means to evaluate the emissions associated with air travel.

DEFRA's methodology for evaluating carbon emissions from passenger flights incorporates a range of factors. These include the aircraft's fuel consumption, flight distance, type of aircraft, and even the indirect effects of high-altitude emissions. The aim is to offer a holistic view of a flight's environmental impact. By developing this standardized approach, DEFRA not only aids the aviation industry in understanding and reducing its carbon footprint but also provides a reliable reference point for policymakers and environmental advocacy groups.

Versioning: Add methodology_version to pin a specific Conversion Factors year (e.g., "2024"). If omitted, SQUAKE uses the latest supported year.


Sample API Request

{
  "expand": ["items"],
  "items": [
    {
      "type": "flight",
      "methodology": "DEFRA",
      "external_reference": "test_4",
      "number_of_travelers": 2,
      "origin": "LON",
      "destination": "LAX",
      "booking_class": "first",
      "aircraft_type": "737",
      "radiative_forcing_index": true,
      "energy_scope": "wtw",
      "methodology_version": "2024"
    }
  ]
}
  • Default Values

    • "booking_class": "average"

    • "energy_scope": "wtw"

    • "radiative_forcing_index": true

    • "methodology_version": latest supported DEFRA year (default if omitted)

  • Calculation Specifics

    • An 8% uplift is applied to Great Circle Distance (GCD) to account for indirect paths, delays, etc.

    • If both distance_in_km and origin/destination are provided, distance_in_km takes precedence.


API Request Items

  • "type": "flight" (required)

  • "methodology": "DEFRA" (required)

  • "methodology_version": DEFRA Conversion Factors year (e.g., "2024"). Optional; if omitted β†’ latest supported year.

  • "external_reference": Unique identifier (max 128 chars).

  • "number_of_travelers": Minimum 1 (default: 1).

  • "origin" / "destination": Flexible formats (postal, IATA/ICAO ^[A-Z]{3,4}$, UN/LOCODE ^[A-Z]{2}\W?[A-Z2-9]{3}$, or "lat,lon").

  • "distance_in_km": If present, overrides origin/destination resolution.

  • "booking_class": If not provided, pass fare_class + airline to auto-resolve; default: "average".

  • "aircraft_type": IATA/ICAO code; only applied when at least one airport is in the UK.

  • "fare_class" / "airline": Mutually exclusive with "booking_class".

  • "radiative_forcing_index": Apply high-altitude climate impact multiplier (default: true).

  • "sustainable_fuels": Indicates SAF use (reduces emissions in SQUAKE; not part of official DEFRA factors).

  • "carbon_reduction_percentage_of_total": Fraction 0–1 from SAF; default: 0.

  • "energy_scope": "wtw" (default) or "ttw".


Aircraft Type Distribution

Domestic
Short-Haul
Long-Haul

32N

32N

32N

32Q

32Q

32Q

319

318

320

320

319

321

321

320

332

AT4

321

333

AT5

332

339

AT7

333

343

738

359

359

D38

AT7

338

ER3

7M8

7M8

ER4

7M9

738

E70

733

752

E90

734

763

E95

735

764

J41

736

772

SF3

737

773

738

77F

739

77W

752

788

753

789

763

781

772

77W

788

789

221

223

CR9

DH8

E70


Sample API Response

{
  "carbon_quantity": 15273823,
  "carbon_unit": "gram",
  "items": [
    {
      "carbon_quantity": 15273823,
      "carbon_unit": "gram",
      "external_reference": "test_4",
      "type": "flight",
      "methodology": "DEFRA",
      "methodology_version": "2024",
      "distance": 8804.0,
      "distance_unit": "kilometer"
    }
  ]
}

Versions

  • Behavior: If methodology_version is omitted, SQUAKE automatically applies the latest supported DEFRA Conversion Factors year. Pin a year for reproducibility and audit readiness.


Bibliography

  • UK Government β€” Greenhouse gas emissions: Research & statistics: https://www.gov.uk/environment/greenhouse-gas-emissions#research_and_statistics

  • Bramwell, R., et al. (2024). Government Greenhouse Gas Conversion Factors for Company Reporting β€” Methodology. (Methodology paper PDF).

Last updated

Was this helpful?