Chris Rea could cut Christmas journey home's carbon footprint by 88 per cent

A modern electric version of the Mini would be responsible for roughly 11kg of emissions, while the most efficient electric cars could bring the figure down to 8kg.

Dr Stuart Walker and Professor Rachael Rothman estimate Chris’ new electric car might manage around six kilometres per kWh, giving total emissions for the trip of around 11kg. A major factor is how efficient the vehicle and its batteries are. Although it’s considered a design classic, the Mini’s lack of aerodynamic efficiency means it uses more power per mile than a modern electric vehicle and will therefore discharge its batteries more quickly.

Only 5kg of emissions would be generated by Chris Rea’s trip if it were taken by train, according to the new research - reducing his carbon footprint by 88 per cent.

The calculation is made by considering a Tube journey from St John’s Wood to Kings Cross, and then heading to the North East via electric train on the East Coast Main Line.

Chris Rea would have to set off earlier than usual this year, as planned engineering works have meant Kings Cross is closed from 24 December, with services to the capital stopping at St Neots and Peterborough.

Dr Walker said: “It's interesting to note that emissions of both the car and train journey have fallen by around 80 per cent since the song was written, but the train is still the greener way to travel.

“Since both are now linked to the emissions of the UK electricity supply, it seems likely that both will continue to fall, but perhaps the train will always be the best option for this journey.

“We also calculated the emissions of some of Chris’ favourite vehicles, including a Ferrari (148kg CO2) and a tiny Fiat 500 (37kg), but none could beat the train. We found that the emissions of the rail journey would fall over time, helped by the electrification of the line and the gradual reduction in emissions as more and more of our electricity is supplied by renewable energy.”