Government's air passenger tax cut spurs launch of new UK flight routes that emit double the CO2 of trains

As the government halves the air passenger duty (APD) airlines pay on UK flights, our comparison of flight and train prices finds train travellers paying a third more on average. Just 3 out of 10 routes were cheaper by train, even when buying 31 days or more in advance. 

We also compared the CO2 emitted on the same routes, and found plane journeys emitted 118% more CO2 on average. 

While the government cut APD, rail fares were increased by 5.9% this year. The UK pledged to reduce its greenhouse-gas emissions to net zero by 2050.

Flight and train routes compared

Our snapshot research compared flying vs taking the train on 10 UK journeys between 7 and 15 April. This included travel to popular UK holiday destinations such as Newquay, Bournemouth and Edinburgh.

Across all 10 routes we found that people pay 35% more on average to travel by train, but the difference on some routes was more stark. 

A direct flight between Edinburgh and Bournemouth flying out on 8 April and returning a week later was £38. The train journey, with two changes each way was £127 - more than triple the price. That’s despite finding the cheapest fare possible - with a split save journey outwards and an advance train ticket return - and the return train journey taking 16 hours in total. 

On the same Edinburgh to Bournemouth route, the CO2 emissions per passenger were 218kg on the plane (according to Atmosfair) and 95kg on the train (according to EcoPassenger).

Table notes: Numbers rounded to nearest £/kg

New domestic routes launched

From (1 April) a cut to the air passenger duty (APD) for domestic flights will see airlines’ tax bills halved from £13 to £6.50 per passenger, with airlines incentivised to introduce more domestic routes as a result. 

Ryanair said it had added new domestic flight routes to its schedule as a direct result of the APD cut.

A Stansted to Edinburgh route will run three times per day. And a Stansted to Cornwall route is available three times per week.

We compared Ryanair’s Stansted to Edinburgh route with the equivalent train journey and it was 75% more expensive to travel by train while the flight emitted twice the CO2. 

In 2021, the Rail Delivery Group - the rail industry membership body - conducted research showing that a 50% cut in APD could result in 222,000 fewer rail journeys a year. It estimates that these extra plane journeys equate to 27,000 tonnes of extra carbon emissions. 

In comparison, France has proposed banning domestic flights where equivalent journeys taking less than two-and-a-half hours on its rail and bus networks are available. France’s railways are better equipped than the UK’s according to the Global Competitiveness Report 2019 by the World Economic Forum. France ranked 13th in the world for its quality of railroad infrastructure compared to the UK ranking 29th.

Our research

Which? compared 10 routes across the UK for return train and flight fares for the 8 and 15 April (with the exception of Bristol to Aberdeen, as there were no flights running on these dates, so we looked at fares for the 7^th to 14^th April). Each comparable route was checked on the same day and was at least 31 days in advance. For both train and plane journeys, Which? recorded the cheapest ticket it could find on that day, but excluded any journeys arriving at the destination after midnight and leaving before 6am.  Flight prices were checked using Skyscanner and train prices were checked using Trainline (excluding booking fees) to find the cheapest possible fare, opting for advance tickets or split tickets where available. Carbon emissions data for train journeys was taken from EcoPassenger. Carbon emissions data for plane journeys was taken from Atmosfair. Return journey times do not factor in time spent in the airport prior to boarding or time taken to travel from city centres to airports. Some train routes involve connecting travel by London Underground.