Leonardo DiCaprio is one of Green Buzz's Environmental Activists Celebrities. Back in 1998 he established the Leonardo DiCaprio Foundation advocating the environmental issues. His website has an area where he talks about the Earth, too. His activities are broad, as he is on the board of the Natural Resources Defense Council, Global Green USA and International Fund for Animal Welfare.
Watch Leonardo DiCaprio's Powerful Speech on Climate Change at the UN - "We only get one planet. Humankind must become accountable on a massive scale for the wanton destruction of our collective home. Protecting our future on this planet depends on the conscious evolution of our species."