Flight: TIM

💡 High-Level Description:

The Travel Impact Model (TIM), developed under the aegis of Google and its independent Advisory Committee, revolutionizes the carbon footprint estimation for air freight, employing a cutting-edge, comprehensive methodology. Drawing from public and licensable datasets, TIM meticulously calculates per-seat or per-passenger CO2e emissions by considering a range of variables including flight details, aircraft specifics, and load factors, ensuring a robust and transparent emission estimate. Notably, TIM's methodology stands apart for its dedication to accuracy, validated against real-world data, and its ambition to cover the complete climate impacts of aviation, making it a future-proof tool that evolves alongside aviation technologies and practices.

By focusing on the precise calculation of emissions and offering these insights through a freely accessible API, TIM empowers stakeholders across the aviation sector—from airlines to passengers—to make informed decisions regarding their carbon footprint. The model's governance structure, featuring a mix of industry, academic, and policy experts, guarantees that TIM remains at the forefront of scientific advancement, maintaining its relevance and utility in facilitating sustainable aviation practices.

API Request

{
    "expand": [
        "items"
    ],
    "items": [
        {
            "type": "flight",
            "methodology": "TIM",
            "origin": "SYD",
            "destination": "MEL",
            "number_of_travelers": 1,
            "booking_class": "economy",
            "airline": "QF",
            "flight_number": "QF0479",
            "aircraft_type": "73H",
            "external_reference": "test",
            "energy_scope": "wtw"
        }
    ]
}

• Default Values

  • "booking_class": "economy"

  • "energy_scope": "wtw"

API Request Items

• "type": "flight" (required)

• "methodology": "TIM" (required)

• "external_reference": A unique identifier that helps you link the resulting emissions to the requested item. Especially useful if multiple items are requested since SQUAKE cannot guarantee to keep the same order. The maximum length is 128 characters.

• "number_of_travelers": Minimum value is 1. The default value is 1.

• "origin": SQUAKE will try to resolve the origin/destination regardless of its format. Ideally, for addresses use the Post standard, for airports use IATA/ICAO code (format: ^[A-Z]{3,4}$, e.g. "MUC"), for other locations used in trade and transportation use UN/LOCODE codes (format: ^[A-Z]{2}\W?[A-Z2-9]{3}$, e.g. "DEHAM"). You can also pass lat/long (format: ^[-+]?\d{1,3}\.\d{1,10}\s?,\s?[-+]?\d{1,3}\.\d{1,10}$, e.g. "+40.712,-74.006").

• "destination": SQUAKE will try to resolve the origin/destination regardless of its format. Ideally, for addresses use the Post standard, for airports use IATA/ICAO code (format: ^[A-Z]{3,4}$, e.g. "MUC"), for other locations used in trade and transportation use UN/LOCODE codes (format: ^[A-Z]{2}\W?[A-Z2-9]{3}$, e.g. "DEHAM"). You can also pass lat/long (format: ^[-+]?\d{1,3}\.\d{1,10}\s?,\s?[-+]?\d{1,3}\.\d{1,10}$, e.g. "+40.712,-74.006").

• "booking_class": If you don't pass a booking_class, then fare_class and airline are highly recommended. SQUAKE will then automatically resolve the correct booking_class. For TIM, economy is the default.

• "aircraft_type": Aircraft type in the IATA or ICAO format.

• "fare_class": The combination of fare_class and airline is mutually exclusive with booking_class. This is a single letter, e.g., Y, J, etc.

• "airline": The IATA Designator of an airline, e.g., LH. Airline names are also supported, SQUAKE will then automatically resolve it. The combination of fare_class and airline is mutually exclusive with booking_class.

• "flight_number": Flight numbers should include the airline designator, e.g., "BA115". "115" also works with airline passed separately.

• "departure_date": The departure date in the format YYYY-MM-DD, which is aligned with ISO 8601
• • "sustainable_fuels": Indicates the usage of sustainable fuels. This lowers the computed emissions in SQUAKE but is not part of the current official emissions frameworks.

• "carbon_reduction_percentage_of_total": The percentage of emissions reduction through the usage of sustainable fuel. The minimum value is 0, and the maximum value is 1. Default value is 0.

• "energy_scope": Values are ttw or wtw. Default value is wtw.

Sample API Response

{
    "carbon_quantity": 78418,
    "carbon_unit": "gram",
    "items": [
        {
            "carbon_quantity": 78418,
            "carbon_unit": "gram",
            "external_reference": "test",
            "type": "flight",
            "methodology": "TIM",
            "distance": 706.0,
            "distance_unit": "kilometer",
            "algorithm_specifics": {
                "dataset_type": "google_tim"
            }
        }
    ]
}

API Response Items: Algorithm Specifics

• "dataset_type": "google_tim" Refers to the standard Travel Impact Model (TIM) methodology. This uses current and modeled flight data to estimate emissions based on flight-specific variables such as aircraft type, route, and cabin class. It ensures high accuracy and is aligned with TIM's publicly documented methodology.

• "dataset_type": "google_tim_fallback" Indicates that the input data provided was insufficient for precise matching, so a fallback logic was applied by SQUAKE to estimate emissions. This may occur if essential data like flight number or airline is missing, or cannot be matched reliably. The fallback method may lead to less accurate results but still provides a reasoned approximation.

• "dataset_type": "historical_google_tim" Refers to TIM's historical emissions dataset, structured into three tiers based on data availability and accuracy. The tiers represent a hierarchy of precision:

  • Tier 1: TIM past direct flight emissions

    • Requires: Carrier, Flight Number, Origin, Destination, Departure Date, Cabin Class

    • Use: For direct flights only

    • Accuracy: Highest

    • Description: Uses actual scheduled flight data from 2019, covering operating and codeshare flights. Provides the most accurate CO₂e estimate when full flight details are known.

  • Tier 2: Typical flight emissions

    • Requires: Origin, Destination, Cabin Class

    • Use: For direct or indirect flights

    • Accuracy: Medium

    • Description: Uses typical emissions based on historical routes between two airports, averaging over multiple possible flight paths. Useful when flight numbers or dates are unknown.

  • Tier 3: Distance-based emission factors

    • Requires: Distance travelled, Cabin Class

    • Use: For direct or indirect flights

    • Accuracy: Lowest

    • Description: Applies generalized emission factors per kilometer per seat, segmented by cabin class. Should be used only when flight routing data is unavailable.

Bibliography

• [External] Travel Impact Model Emissions Data (Oct 27, 2022). TIM Team. For more details, check: https://github.com/google/travel-impact-model