The campaign to fight global warming has finally heated up in India as Hindi film industry icon Amitabh Bachchan  decided to be the one to spread the message.Big B on Tuesday night urged others to join the global cool movement and for this, stylish star of Factory Girl and Layer Cake Sienna Miller came down from London for the project."It's almost too late," said Amitabh. "Other countries need to sign on," said Sienna Miller.he two stars also come together in a film that aims to fight climate change. With co-stars like Tony Blair and Heather Graham, people should stop and listen but till that hits screens the Big B says it's us who can make the difference.