British Prime Minister Tony Blair is starring in a short film with actress Sienna Miller to promote climate change awareness. The 54-year-old Labour Party leader plays a 'carbon crusader' in the upcoming Global Cool, directed by Indian film veteran Shekhar Kapur and premiering at this weekend's (begs09June07) International Indian Film Academy (IIFA) awards ceremony. Blair says, "I've been preparing for this role for the last 10 years, "It was great to be part of Global Cool. But remember, I was only one of a billion people saving the planet in this movie - and they are all stars."