One form of symbolism in the movie is who was chosen to speak in the movie. We cna start with the narrator of the movie, Leonardo Dicaprio (Leo). The general public is bound to take more interest in, and even believe, what Leo has to say than if you or I were up there instead. The public has seen and some have fallen in love with the actor, or hold him on a high pedestal, and therefore will take what he says more to heart. The interviews and commentary given in the movie also presents prominent figures in todays society. The commentators reach all scopes of culture and academia. With speakers such as Stephen Hawking, Mikhail Gorbachev, and Wangari Maathai, we are given relation to the scientific, political, and cultural communities. And the credibility and achievements of these speakers only leaves us more interested and worried about the topic, which is precisely the aim of the documentary.
The images displayed throughout the movie also speak their own words. For example, the cover of the poster for the movie displays the Earth with a human footprint on it, invoking the impression we are leaving on the Earth and relating to the term "carbon footprint". Images of natural disasters (i.e. tornadoes, hurricanes, etc.) leave us with a daunting thought in our minds, the fact that any of these could happen to us and our loved ones gives us a sense of worry. Images of animals and humans in distress give us a feeling of sympathy. One image in particular of a polar bear walking out of its element in a garbage dump, burns an image into the viewers mind that something is wrong.
Through the use of symbols, the powers behind the movie achieve their aim of a sense of urgency and information. The symbols all correlate to the big picture and send a barrage of emotions to the viewer. When all of these aspects and emotions accumulate in throughout the movie, the overall tone (worry,urgency) and aim of the movie are well-achieved.