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.
It is estimated that his 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.
Wedding of Charles and Diana
Wedding of Charles and Diana
Lady Diana Spencer with her father Earl Spencer on their way to St. Pauls Cathedral in the City of London, for her marriage to The Prince of Wales.
Exactly a month before the Royal wedding and Fred English, 85, patriotic from hat to shows, has his Manor Road house in East Molesey, Surrey, decorated for the Royal wedding.
THE OFFICIAL ROYAL WEDDING CAKE FOR DIANA SPENCER AND PRINCE CHARLES MADE BY THE ROYAL NAVY'S COOKERY SCHOOL 5FT HIGH AND 255 ILBS HMS PEMBROKE IN CHATHAM
A London Routemaster bus painted with ribbons and bows to look like a giant wedding present.
James Cleverley, 7, and Leisa Winstanley, 11, with their winning plate designs made up to become rare Royal Wedding Presents and presented to them in London. The plates were hand painted and made into a limited edition - one for each of the children and one of each for Prince Charles and Lady Diana. James of Horningstoft, Norfolk and Leisa, from Truro, Cornwall, entered their designs in the Blue Peter Royal Wedding Plate competition on the BBC.
A message from the City of London Corporation pasted onto the railway bridge at the bottom of Ludgate Hill, London, and destined to be read by the Prince of Wales and Lady Diana Spencer when they are en route to their wedding at St. Paul's Cathedral.
A firework display in Hyde Park, London, to celebrate the marriage of Prince Charles and Lady Diana Spencer.
Grandmother Kathleen Lucus knits to pass away the hours outside Buckingham Palace, London, one of many who have made all night vigils waiting for the Royal wedding of Lady Diana Spencer to Prince Charles.
Scenes outside St Paul's Cathedral in London as young and old awaken from a night in sleeping bags to secure vantage points for seeing the royal wedding.
Brian Balmer, a 19 year old Student from Hindsford, Atherton near manchester, stakes his claim to a seat outside at St. Paul's Cathedral to watch the wedding.
Nancy Reagan at Fitzroy Square in London. She will represent her husband, US President Ronald Reagan, at the wedding of Prince Charles and Princess Diana.
Balloons join the escort of the Blues & Royals for Prince Charles and the Princess of Wales as they drive in an open landau to Waterloo Station from Buckingham Palace. Behind is Lt Col Andrew Parker-Bowles
Earl Spencer (right) accompanies his daughter Lady Diana Spencer at her wedding to the Prince of Wales at St Paul's Cathedral, London.
A FINAL WAVE TO THE CROWDS FROM THE PRINCE OF WALES ACCOMPANIED BY PRINCE ANDREW (RIGHT) BEFORE ENTERING ST. PAUL'S CATHEDRAL, LONDON
Earl Spencer (right), accompanies his daughter Lady Diana at her wedding to the Prince of Wales, at St Paul's Cathedral, in London. * 25/1/96 A Church of Scotland clergyman claimed that the Earl confessed to him in 1947 that he had a romance with the young Princess Elizabeth before she became Queen.
Earl Spencer leads his daughter, Lady Diana Spencer, down the aisle in St Paul's Cathedral, for her wedding to the Prince of Wales. * 29/7/81 of Earl Spencer leading his daughter Lady Diana Spencer down the aisle of St Paul's Cathedral, London, for her wedding to the Prince of Wales.
On the balcony, Buckingham Palace, the Princess of Wales laughs as she places her hand on the shoulder of Edward Van Cutsem, one of the Page boys at her wedding to the Prince of Wales. Also visible are Clementine Hambro (a bridesmaid) and Nicholas Windsor (Page Boy).
The newly married Prince and Princess of Wales (formerly Lady Diana Spencer) kiss on the balcony of Buckingham Palace after their wedding ceremony at St. Paul's cathedral.
The Prince of Wales and his bride Lady Diana Spencer during their wedding ceremony at St Paul's Cathedral.
The Prince and Princess of Wales leave St. Paul's Cathedral in a carriage after their wedding on 29 July 1981.
The official group photo at the wedding of the Prince and Princess of Wales.
The Queen Mother and Prince Andrew, driving back from St Paul's in an open carriage after the wedding of Prince Charles to Lady Diana Spencer.
The Princess of Wales in her bridal gown at Buckingham Palace after her marriage to Prince Charles at St. Paul's Cathedral.
Prince Charles, Prince of Wales and Diana, Princess of Wales leave St. Pauls Cathedral in London following their wedding on July 29, 1981.
Diana, Princess of Wales is led down the aisle of St. Paul's Cathedral by her proud father, Earl Spencer, on her wedding to Prince Charles, Prince of Wales on 29 July 1981.
Diana, Princess of Wales enters St. Paul's Cathedral on the hand of her father, Earl Spencer, for her marriage to Prince Charles, Prince of Wales on 29 July 1981.
Queen Elizabeth II and the Duke of Edinburgh make their way to St Paul's Cathedral for the wedding of the Prince of Wales and Lady Diana Spencer.
**FILE PHOTO** Diana, Princess of Wales, wearing an Emanuel wedding dress, and Prince Charles, Prince of Wales leave St. Paul's Cathedral following their wedding on 29 July 1981.
Designers Elizabeth and David Emanuel are holding an auction of dresses worn by the late Princess Diana. The dresses are to go up for auction on June 8, 2010 in London, at specialist vintage fashion auctioneers Kerry Taylor Auctions.
The Prince of Wales and Prince Andrew make their way to St Paul's Cathedral
The Duchess of Kent and her daughter Lady Helen Windsor on route to St Paul's Cathedral for the wedding of the Prince of Wales and Lady Diana Spencer
The newly married Prince and Princess of Wales leaving St Paul's Cathedral past the Press Association Building on Fleet Street, on their way back to Buckingham Palace.
The Prince and Princess of Wales walking down the aisle after the wedding service at St Paul's Cathedral.
The Prince and Princess of Wales on the balcony at Buckingham Palace after their wedding
The Prince of Wales, and his supporters, Prince Andrew and Prince Edward, arrive at St Paul's Cathedral for his wedding to Lady Diana Spencer.