During one hour and a half, the American movie An Inconvenient Truth stands up Al Gore’s ideas about climate change. This film was immediatly a box office success in 2006. But, in fact, sounds, music and pictures are chosen and set up with the intention of doing it. It is quite a movie grammar which is used to finally persuade each spectator. This article tries to decode the message during successively the five parts of the film : problem, proves, impacts, causes and individual and collective responses.