The figures given in Green Traveller's train journey planners for carbon emissions for trains and planes are provided using information provided by EcoPassenger, a cooperation between the International Union of Railways (UIC), its European members, Ifeu (the German Institute for Environment and Energy) and IVEmbH (routing system and software). The UIC has 201 members, including rail operators, infrastructure managers, railway service providers and public transport companies.
Please note, the emissions are provided on greentraveller.co.uk are intended as a general guide to emissions given for the point to point journey from London to the destination. Working out the exact emissions is a complicated process! The emissions data for trains do differ between countries depending on the types of vehicles used (such as railcars, locomotives and other train configurations), the type of energy carriers and conversion used as well as differences from the method and national mix of electricity sources. We have input this information from EcoPassenger using its online search tool, but emissions do vary depending on the exact route, so we strongly advise that should you want to find a more accurate figure for any particular route then you key in the appropriate details in EcoPassenger's online search tool on its website.
Only those emissions are considered which are directly caused by the operation of vehicles and the energy consumption of the generation of final energy (fuels and electricity).
Not included are:
the production and maintenance of vehicles
the construction and maintenance of transport infrastructure
additional resource consumption, such as administration buildings, stations, airports, etc.
The figures given on greentraveller.co.uk are for carbon emissions only. For flights, they do include "CO2-emissions with climate factor" in the settings. This 'RFI' Factor takes into account the additional climate effects of other GHG emissions, especially for emissions in high altitudes (nitrogen oxides, ozone, water, soot, sulphur). However, EcoPassenger does provide more details information for each trip by train and plane (and also car) on the following other environmental impact metrics:
the particulate matter (human toxicity, greenhouse effects)
the nitrogen oxides (acidification, human toxicity, summer smog)
the non methane hydrocarbons (summer smog / human toxicity)
However, the methodology report states that land use, noise and depletion of the ozone layer were not taken into consideration and for electricity driven rail transport the risks of nuclear power generation from radiation and waste disposal are also not considered.
Rail journeys EcoPassenger's website says "The specific energy consumption values for EcoPassenger are derived from the Railenergy database for the year 2005 /UIC 2007/ and, for France and Germany, from country specific calculators Ecocomparateur /ADEME 2006/ and UmweltMobilCheck/IFEU 2006/. These values will be updated every year from UIC energy/CO2 database.
A specific value per passenger-km for different train service type has been used for eight countries: Belgium, Switzerland, Germany, Spain, Finland, France, United Kingdom, Italy and Sweden. For all other countries, a passenger kilometre weighted average value for each service type was used, based on the eight countries values. These values include the average country and service type specific load factors and are used as standard for the emission calculation in EcoPassenger."
Length of a route EcoPassenger states that "The length of the train routes is determined by the polygon defined by all in-between stops of a train. The length of the train route between two connected stations is calculated by the line of sight distance which is extended by 20%-30% depending on cases."
Flights A flight is divided in the following flight phases: Taxi (rolling traffic); Take-off and climb; Cruise; Dive and landing. EcoPassenger's website says "The definitions for the flight phases are taken from /DLR 2000/. The length of each phase depends on the total distance, because for shorter distances the altitude of the cruise is lower. /DLR 2000/ defines flight phases fort the distance classes 250 km, 500km, 750 km, 1000 km und over 1000 km.
In addition, EcoPassenger says that its system "has no access to flight timetable data for an online routing. But the possible flight relations (including 1-stop flights) are determined based on real flight data. A flight relation between two airports was added to the system, if there is at least one flight per week available. The system considers all direct flight connections and 1-stop flight connections, if the total flight distance does not exceed the line of sight distance between start and destination by 100%."
See what we mean when we say it's complicated?! There's a whole lot more information about the calculations on the EcoPassenger site. Our advice is that if you're looking for exact emissions, particularly where routes differ (e.g via Lille or Paris), please use the EcoPassenger search tool on its website www.ecopassenger.org.