ES News email The latest headlines in your inbox twice a day Monday - Friday plus breaking news updates Enter your email address Continue Please enter an email address Email address is invalid Fill out this field Email address is invalid You already have an account. Please log in Register with your social account or click here to log in I would like to receive lunchtime headlines Monday - Friday plus breaking news alerts, by email Update newsletter preferences

Clarence House has defended the Prince of Wales after it was revealed that he flew more than 100 miles in a private helicopter to make a speech about lowering aircraft emissions.

The royal flew 125 miles from Highgrove to Cambridge to speak to scientists from Cambridge University's Whittle Laboratory, who are leading research into the decarbonisation of air travel.

After his return, Charles flew 178 miles on two journeys, the Mirror reports.

It is estimated that the helicopter's total journey of 368 miles cost at least £12,000 and caused about 2.5 tonnes of carbon emissions.

In a statement, Clarence House said the carbon footprint left by the 71-year-old's travel was offset every year.

"The prince is not personally involved in decisions around his transportation arrangements, though he ensures all carbon emissions are offset every year," a spokesperson said.

"They are made based on what is possible within the constraints of time, distance and security.

"In order for him to undertake as many engagements as he does across the UK and around the world he sometimes has to fly.

"As he has often said, as soon as there is a more sustainable way of making these journeys, he'll be the first to use it."

It is estimated that Charles could have cut his emissions down to just 0.2 tonnes if he had travelled by car.

Campaign group Republic's chief executive Graham Smith told the newspaper: "He wants to play the role, but not walk the walk.

"His view seems to be that it's one rule for him and one rule for the rest of us.

"Driving or using the train would have been pretty easy."

The royal recently faced criticism for flying 16,000 miles in private jets and helicopters in the days leading up to this year's World Economic Forum in Davos, Switzerland.