Analysis of more detailed rail data has shown rail travel creates 10 times less carbon emissions per passenger than the equivalent car journey and 13 times less than travelling by plane.
The figures, which take into account engine type, fuel type, journey distance, occupancy and carriage layout, suggest that long distance rail is even more sustainable than the industry believed.
Until now, comparisons have been based on data and analysis from the Department for Environment, Food & Rural Affairs (Defra).
The new, more detailed figures have been calculated as part of Green Travel Pledge, a major initiative from the Rail Delivery Group, Great British Railways Transition Team, Thrust Carbon, Fabrik and Black Box Partnerships.
They show that the equivalent journey from London King’s Cross Station to Edinburgh Waverley Station produced 12.5kgCO2e of carbon emissions per passenger by train, compared to 136.4kgCO2e by car and 165.1kgCO2e by plane.
Detailed carbon emission data for rail journeys across Britain will be made available to businesses later this year.
Kit Brennan, Founder and Head of Product at Thrust Carbon which has helped to develop the methodology behind the new rail carbon calculations, said: “Businesses always knew that rail was the greenest way to travel; but for the first time we now know just how much greener it is.
“This is the first time we’ve combined such granular data on occupancy, journey distance, carriage layout and a number of other factors to provide an accurate and reliable figure for greenhouse gas emissions.
“We are excited about expanding the rail carbon calculator to include rail routes across Britain to support businesses to travel more sustainably in future.”
Jacqueline Starr, CEO at the Rail Delivery Group, said: “This is a preliminary result but it shows what we all know – that rail is by far the most sustainable travel choice for businesses and business travellers.
“Choosing rail over more polluting methods, like cars and planes, is an easy way to help protect the planet.
“We want to empower businesses to make greener travel choices.
“Businesses have been asking for a tool to demonstrate the environmental benefits of shifting business travel journeys from planes and cars to rail. We are now delivering this.
“We are really excited to be rolling out accurate and reliable carbon emission data for rail routes across Britain as part of our Green Travel Pledge later this year so businesses can accurately demonstrate how rail travel is helping them to reach their environmental, social and governance (ESG) goals.”