As he is an adult the police will not do anything at all unless there is some reason to think that a crime is involved . It is not an offence for an adult to ' go missing' it happens 100s of times every day. The most the police will do is to take his description in case he turns up some where and asks for help or can not be identified. Even if the police did find him , for example if he was arrested for some reason, they will not tell you about it unless he gives permission for you to know where he is.