Plane Freight Defra

This category is deprecated. The latest DEFRA methodology for plane freighting can be found here and here .

This category allows the user to calculate air freight emissions using the latest Defra data and advice.

To use this category, users must specify both a distance and a mass of freight transported. Mass should be specified using the mass profile item value. Users can set freight distance in one of three ways: (1) directly, by specifying an actual distance flown; (2) indirectly, by specifying departure and destination locations; or (3) approximately, by using generic distance categories. In all cases, the returned value represents CO₂ emissions attributable to the transported freight over the distance specified.

Specifying departure and destination locations

Users can enter either the latitude/longitude of the departure and destination locations or IATA codes for the respective airports involved in travel. In both cases, Discover calculates the distance based on a 'great-circle' calculation (using the haversine formula), and inflates by 9% to account for congestion and indirect routing.

To use this method, select the auto category via drill down. Next, enter departure and destination locations by setting one of the following groups of profile item values:

• lat1, long1, lat2, long2 (i.e. a pair of latitude and longitude coordinates)

• IATACode1, IATACode2 (i.e. a pair of airport IATA codes)

The IATA code calculation made by reference to airport longitude and latitude data obtained from the /transport/plane/generic/airports category. If no IATA codes are specified but long1 is set to a valid value then the great circle distance is calculated directly between long1, lat1 and long2, lat2 (and inflated by 9%). Longitude must be in the range -180 to 180 with negative numbers representing eastern longitudes. Latitudes must be in the range -90 to 90 with negative numbers representing southern latitudes.

Depending on the distance calculated, Discover selects the appropriate CO2 emissions factor (kg CO2 per mass km). A short haul emissions factor is used for flights under 3700 km, while a long haul factor is used for those greater than 3700 km. For flights originating and landing within a single country, the domestic emissions factor is used.

Directly specifying a distance

Users can alternatively specify the distance of freighting directly. To use this method, specify the type of flight by selecting domestic, short haul, or long haul via drill down. Next, set the distance flown in the distance profile item value. Discover calculates emissions according to this distance and the selected (domestic, short-haul or long-haul) emissions factor (kg CO2 per mass km).

Generic distance categories

If flight distances, or specific freight departure and destination locations are not available, users can calculate flight emissions based on 'typical' distance categories. Discover follows DEFRA/DECC in assuming the following typical one way flight distances:

• domestic = 463 km

• short-haul = 1108 km

• long-haul = 6482 km

To use this method, specify the type of flight by selecting domestic, short haul, or long haul via drill down as above, but leave the distance profile item value unspecified. In this case, Discover calculates freighting emissions according to the the appropriate typical distance.

Other Optional Parameters

If users wish to incorporate the effects of radiative forcing, the useRFI profile item value should be set to true (default value is false). The value of the the radiative forcing index can be set using the radiativeForcingIndex profile item value, defaulting to 1.9 otherwise. For an explanation of the radiative forcing index (RFI) see the here.