The Belgian and Austrian railway companies NMBS and ÖBB claim that the new night train between Brussels and Vienna is 10 times more environmentally friendly than airplanes. This claim was published in many Belgian media as ‘Het Laatste Nieuws’, ‘Knack’ and ‘Dewereldmorgen’. The claim turns out to be uncheckable.
Both NMBS and ÖBB were unable to explain where the number 10 comes from. ÖBB referred to their own web page which did include the number 10, but no source to any research files. NMBS, on the other hand, referred to the online calculation module Eco Passenger but contradicted themselves twice. They mentioned a factor 10 as well a factor 14 but couldn’t explain why.
Reliable calculator, inaccurate numbers
Most of our experts referred to Eco Passenger. This tool calculates how much CO2 emissions would be released over the same distance using a plane, car or train. You can change the variables such as ‘with climate factor’, or ‘occupancy rate’. This leads to very varied results.
Monique Sys, institute director of the Institute for Environment & Sustainable Development (University of Antwerp), confirms the reliability of the calculator. But she concludes that trains are 5 times more ecofriendly than airplanes, not 10.
Others, such as WWF, claim that trains are only 5 times more environmentally friendly than airplanes at a distance of 500 km. And even less, 2,8, on a distance over 1000 km.
The Belgian politician Kim Buyst from the Flemish green party Groen confirms that the results vary a lot and go from 5 to 20 times more environmentally friendly. She claimed that there would never be an unambiguous number because the CO2 emissions depend on too many factors.
Results with Eco Passenger
5 is also one of the numbers that we came upon using Eco Passenger. But we also got outcomes between numbers 4 and 20, depending on the variables we used.
You can test Eco Passenger yourself, using this link: http://ecopassenger.org/bin/query.exe/en?L=vs_uic
Different trains have different CO2 emissions
Depending on what train is used for a journey, a different amount of CO2 emissions is released. In our case, the night train from Brussels to Vienna, electricity is used for the most part of the journey, which definitely makes it more environmentally friendly than trains driven by diesel. But besides the fuel, also the occupancy rate and the discarded distance can influence the result.
Conclusion
We argue that this claim is uncheckable. There are simply too many factors on which the number varies.
RESEARCH | ARTICLE © Louise Anthonissen, Thea Cipido, Topsana Du Bois, Jolien Engelen
AP University College, Antwerp, Belgium
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