In taking his message onto the Internet, Charles will follow in the footsteps of Queen Elizabeth, who last week sent her first official e-mail to mark the 60th anniversary of the Commonwealth.
The Prince will say that it is vital to preserve the rain forests in the battle against climate change. He will also warn that deforestation emits more carbon into the atmosphere than the entire global transport sector and explain why he is specifically targeting social networking sites like MySpace, which attract large numbers of predominantly young people to exchange gossip, pictures and listen to music.
The Prince's message will be followed on MySpace by the online 'premiere' of a 90-second public awareness film by his own Rain forests Project for action to slow the rate of destruction of the tropical rain forests.
The Prince, who regularly attends film premieres, will tonight for the first time attend one in which he actually stars.
The film will be shown at the National Geographic Store on London's Regent Street.