Al Gore, 45th vice president of the United States and a controversial public figure, was awarded the Nobel Prize for Peace in 2007 for his efforts to raise awareness about global warming. He has devoted a very large portion of his life to environmental issues, especially in his multiple Academy Award-winning 2006 documentary An Inconvenient Truth, his best-selling book of the same name, and through his Repower America campaign. (Source: Britannica Online Encyclopedia / Photo: openDemocracy/Flickr)