LONDON - Putting his money where his environmentalist mouth is, Prince Charles is swapping gas-guzzling private planes and helicopters for commercial flights, train journeys and biodiesel cars. A longtime champion of green causes, the heir to the throne says action is needed now to avoid leaving a ruined planet to the next generation. "From February, we are going to look at the diary and see what we can do to reduce our carbon footprint," a spokeswoman for the prince's London residence, Clarence House, said Thursday on condition of anonymity in line with royal rules. "Wherever possible, we will be making...