Cut in air travel to London is the equivalent to removing all traffic on the M8 between Glasgow and Edinburgh for two years

Passengers shunning air travel in favour of rail have caused a major reduction in carbon emissions.

A report by sustainable transport alliance Transform Scotland says that train journeys between central Scotland and London rose from a 20% market share to 33% between 2005 and 2015.

The move to rail has saved more than 680,000 tonnes of emissions, said the charity.

That’s the equivalent to removing all traffic on the M8 between Glasgow and Edinburgh for two years, it claimed.

The figures come from Transform’s A Green Journey to Growth report, which said that rail use moving towards a 50% market share between central Scotland and London would lead to significant additional emissions savings.

Further emission reductions could be expected through the introduction of the new Azuma trains on the East Coast route, which aim to cut the journey time between Edinburgh and London to four hours.

Transform Scotland estimated that a flight from Edinburgh to London emits 177kg CO2 per passenger, while existing trains emit 34kg per passenger.

But it said an Azuma will emit 28kg - 84% less than a flight.

Transform director Colin Howden said: "The Scottish transport sector has failed to take significant action to tackle climate change, and has recently become the single largest source of carbon emissions.

"However, one area where there has been significant progress is in Anglo-Scottish travel, where rail's share of the travel market has grown strongly over the past decade.

"For Scotland to meet its challenging climate targets, it is imperative that further action be taken to ensure that rail can grow to at least a 50% market share of the Scotland-London travel market over the next decade."

He said this would include increased investment in the rail network, public bodies using the train rather than flying their staff to London, and a fairer taxation system for Anglo-Scottish travel.