The Prince of Wales's private income rose by 7 per cent to more £16m last year, Clarence House accounts showed today.
The money generated by the Duchy of Cornwall - the landed estate given to the heir to the throne - increased by just over £1m to £16,273,000 during the last financial year.
The amount of carbon dioxide (CO2) produced by Charles fell by 18 per cent or 630 tonnes to 2,795 during 2007-08, the accounts revealed.
Clarence House officials said the cut was due to a switch to "green" electricity supplies and a further reduction in travel-related emissions.
The accounts also revealed the cost of the Prince's official travel by air and rail fell 22 per cent from £1.4m to £1.1m.
The journeys by plane and train are paid for by the taxpayer through grants-in-aid.
It was revealed today that five controversial helicopter flights Prince William made while training with the RAF cost more than £50,000.
The trips, which included journeys to a stag-do and the family home of William's girlfriend, Kate Middleton, were criticised as an alleged abuse of military training.
The accounts also showed that Charles's personal costs, referred to as "non-official expenditure", fell from £2.6m to £2.2m.
The amount of tax the heir to the throne paid to the inland revenue dropped by £5,000 to £3,429,000.
Sir Michael Peat, the Prince's top aide, launched the publication of Charles's annual financial review at a press conference.
He said: "It is much the same as in previous years, needless to say, because their royal highnesses' duties remain constant from year to year.
"I hope it shows a good picture. I don't want to sound complacent but I really do believe that the contribution their royal highnesses make to national life continues to develop and broaden and strengthen.
"The Prince of Wales has a special knack of putting his finger on issues of underlying and long-term importance and for seeing beyond fashion and political correctness and there are some good examples in the annual review."
He went on to describe some of the issues Charles has been tackling during the past financial year, including reducing the carbon footprint of his household.
Sir Michael added: "One of the main focuses of the year has been his intensifying and developing work in the battle against climate change.
"We in the household have reduced our emissions by just over 18 per cent during the year to the end of this March - which is not too bad.
"And perhaps more importantly than that, the Prince of Wales has been encouraging others to reduce their carbon emissions as well.
"He's established what's called the May Day Nextwork, which now has 831, no less, participating companies and is the largest network of companies tackling climate change in the UK."Reuse content