Introduction
This library provides an open source Python package for calculating the carbon footprint of transport (UK-focused to begin with). The final version will include transport by land, sea or air, whether freight or business travel, by any mode covered in the Defra GHG Emissions Factors for Company Reporting.
It is currently in pre-alpha stage as several of the distance functions are incomplete (see Contributing and To-do List section).
distance: provide the distance between two locations using a given transport mode These functions are provided from a range of sources at present, some of which need more work, and some of which need replacing.
All distance functions are in the format distance.[mode]_distance(origin, destination, units)
, and the units default to "km".
>>> from transport_carbon import * >>> road_distance('London', 'Leeds') 313.473
The available functions are:
air_distance(origin, destination[, units])
This function is complete. It calculates the great circle distance between two points. The emissions factors already include an uplift to account for non-optimal routing and stacking at airports.
rail_distance(origin, destination[, units])
This function has a working prototype. It is quite successful when used on journeys that are on a single train line (as they should be), however in trying to calculate more complicated journeys it often fails to find a route.
road_distance(origin, destination[, mode[, units])
This function is complete. It is based on the Google Directions API as implemented in the g_directions
module. mode
defaults to "driving" and units
defaults to "km".
sea_distance(origin, destination[, units])
carbon: provide the GHG emissions associated with a form of freight pr business transport The GHG emissions factors are based on the data provided by Defra in their [2013 Government GHG Conversion Factors for Company Reporting](http://www.ukconversionfactorscarbonsmart.co.uk/) now provided in a web service from Ricardo-AEA.
For all functions, ghg_units
defaults to "kgCO2e". Well to tank (upstream) emissions are available using "kgCO2eWTT". Other emissions factors available are "kgCO2", "kgCH4" and "kgN2O".
>>> from transport_carbon import * >>> motorbike_ghg(size="Small") 0.11890999999999999
Business travel
air_ghg([origin[, destination[, ghg_units[, haul[, travel_class[, radiative_forcing]]]]]]
Requires either origin and destination, or haul to be passed. If unspecified radiative_forcing defaults to True
.
bus_ghg([ghg_units[, bus_type]])
If unspecified, bus_type
defaults to "AverageLocalBus".
car_ghg([ghg_units[, select_by[, size[, market_segment[, fuel[, unit]]]]]])
If unspecified, select_by
defaults to "Size", size
defaults to "Average", market_segment
defaults to "UpperMedium", fuel
defaults to "Unknown", and unit
defaults to "km".
motorbike_ghg([ghg_units[, size])
If unspecified, size
defaults to "Average".
rail_ghg([ghg_units[, ghg_units[, rail_type]])
If unspecified, rail_type
defaults to "NationalRail".
ferry_ghg([ghg_units[, passenger_type]])
If unspecified, passenger_type
defaults to "Average".
taxi_ghg([ghg_units[, taxi_type[, unit]]])
If unspecified, taxi_type
defaults to "RegularTaxi", and units
defaults to "PassengerKm".
Freight transport
air_freight_ghg()([origin[, destination[, ghg_units[, haul[, radiative_forcing]]]]]]
Requires either origin and destination, or haul to be passed. ghg_units defaults to kgCO2e and radiative_forcing defaults to True.
cargo_ship_ghg([ghg_units[, ship_type[, capacity[, capacity_unit]]]])
If unspecified, ship_type
defaults to "BulkCarrier". capacity
and capacity_units
default to None
. The capacity units are looked up from the ship type, and the formula returns the average emissions factor for the ship type.
hgv_ghg([ghg_units[, refrigerated[, percent_laden[, hgv_type[, tonnage[, unit]]]]]])
If unspecified, refrigerated
defaults to False
, percent_laden
defaults to "Average", hgv_type
defaults to "All", tonnage
defaults to None
and the formula returns the average emissions factor for the HGV type, and unit
deafults to 'km'.
rail_freight_ghg([ghg_units[, rail_type]])
If unspecified, rail_type
defaults to "FreightTrain".
sea_tanker_ghg([ghg_units[, ship_type[, capacity[, capacity_unit]]]])
If unspecified, ship_type
defaults to "ProductsTanker". capacity
and capacity_units
default to None
. The capacity units are looked up from the ship type, and the formula returns the average emissions factor for the tanker type.
van_ghg([ghg_units[, van_class[, tonnage[, fuel[, unit]]]]])
If unspecified, van_class
defaults to "Average", tonnage
defaults to None
and the formula returns the average emissions factor, fuel
defaults to "Unknown", and unit
defaults to "km".
Carbon Intensity database
No API exists to serve GHG intensity data from Defra so we have created a database ourselves, defra_carbon.py
. All business transport and freight transport options have been added for 2013.
The tables are:
- Activities
- BusinessBus
- BusinessCarsByMarketSegment
- BusinessCarsBySize
- BusinessFlights
- BusinessFerries
- BusinessMotorbike
- BusinessRail
- BusinessTaxi
- FreightCargoShip
- FreightFlights
- FreightHGV
- FreightRail
- FreightSeaTanker
- FreightVan
Contributing
Please contact Jamie Bull at jamie.bull@oco-carbon.com if you would like to assist in developing this package
To-do list
- Add other years to the database. Data for 2012 is available in the same format and so should be easy to add. Other years may be more difficult.
- Create public functions which link distance and carbon calculations. The intended syntax is
travel_carbon.travel_carbon(origin, destination, mode, **kwargs)
- Create the
sea_distance()
function. Some thought has gone into this so please contact if you would like to contribute. - Improve the
rail_distance()
function. A new data source, choosing the start and end station appropriately. - Improve test coverage.