The consumer champion found environmentally-conscious travelers pay about 50% more for certain journeys in the UK if they travel by train rather than plane.

Which? researchers compared the cost of flying with taking the train on the same dates on 10 popular routes across the UK. The snapshot investigation found that in eight instances it was more expensive to take the train, costing 49% more on average than flying.

Taking the train from Birmingham to Newquay cost more than two and a half times the cost of flying on the dates checked. A return train ticket cost £180 while flights cost just £67. The train route Which? looked at also involved making two changes and, including the return journey, would take more than 10 hours longer than flying in total.

The inflated prices for train travel mean families and holidaymakers travelling around the UK face a near-impossible trade-off between low fares and reducing their carbon footprint. The CO2 emissions caused by flying are, on average, six times those caused by taking the train.

Travelling from Bristol to Newcastle by train would cost £172 for a return journey while flights cost almost half this price at £87. A return flight between the two cities would emit 203kg of carbon dioxide per person, compared to the train journey which would emit 33kg per person. The total journey, including both the outward trip and the return, would also take more than six hours longer by train than it would by plane.

The flight routes with the highest carbon emissions were Edinburgh to Bournemouth and Glasgow to Southampton, at 287kg of CO2 per person each. While taking a return trip by train from Edinburgh to Bournemouth would only emit 52kg of CO2 per person – around a fifth of the emissions created by flying – the journey would cost £70 more than flying and take 14 hours longer.

Which? is advising anyone who wants to reduce their carbon footprint while travelling across the UK to do their research to find the cheapest and fastest way to travel by train, through taking advantage of advance booking, railcards, and other money-saving tricks such as split-ticketing.

Rory Boland, Which? Travel editor, said: “As the pandemic continues to cause uncertainty for international travel, many of us are taking holidays closer to home this year. Travelers who choose to take the train face significantly higher fares and journey times, putting those who want to lessen their environmental impact at a disadvantage.

“There are steps that people can take to reduce the cost of travelling by train. Take the time to compare dates and times to see if cheaper fares are available, and look into what railcards you might be eligible for to save up to a third on train travel. You may be able to make further savings by checking if split-ticketing is an option on your chosen route.”