English actress Sienna Miller will be competing with stars like Madonna and Leonardo DiCaprio for the title of ultimate green celebrity.The award is given to a star who uses his or her fame to promote environmental issues, and Playhouse Disney''s Playing for the Planet Awards has announced a shortlist of 10 stars who have been nominated for the Greenest Star prize
Sienna is one of the stars whose work in raising awareness about global warming has been recognized, China Daily reported.
DiCaprio on the other hand has been a tireless campaigner and donor to various green campaigns. The ''Departed'' actor recently made a documentary ''The 11th Hour'' about global warming.
Other contenders include British supermodel Lily Cole, who only works with environmentally friendly companies, and ''Harry Potter'' actress Emma Watson, who has spent time working with the Wild Trout Trust.
Celebrity power couple Gwyneth Paltrow and husband Chris Martin also received a nomination.
The ''Iron Man'' actress has been the face of US environmental campaigns to cut down the use of oil, while her Coldplay rocker spouse travels on an eco-friendly tour bus complete with recycling facilities.
Johnny Depp, designer Stella McCartney, ''Smile'' singer Lily Allen and British actor David Tennant have also made the shortlist.
