Bhopal,October 28 (ANI):Ranbir Kapoor might be a busy man, but that certainly doesn’t stop him from taking time out for a cause.Ranbir's fans in Bhopal had a pleasant surprise on Tuesday when they found the actor riding a bicycle in the city to campaign against global warming.Ranbir had come to Bhopal to shoot for Prakash Jha's Rajniti. He was invited to the campaign by the Green Planet Bicycle Riders Association.