Using his celebrity status to draw attention to the problem of global warming, one of the most important and pressing issues of our time, actor and United Nations Messenger of Peace, Leonardo DiCaprio, travels the globe to witness firsthand the effects of an impending environmental disaster. By visiting ancient melting glaciers and levelled Indonesian tropical forests, DiCaprio unearths an urgent situation and the world's dependence on fossil fuels, going as far as to visit President Obama himself for an in-depth interview. But, can this crusade inspire the climate-change deniers?—Nick Riganas