Severn Suuzuki - The girl who silenced the world for 5 minutes.
In 1992, at the age of 12, Cullis-Suzuki raised money with members of ECO, the Environmental Children's Organization (a group she founded) to attend the Earth Summit in Rio De Janeiro. Along with group members Michelle Quigg, Vanessa Suttie, and Morgan Geisler, Severn presented environmental issues from a youth perspective at the Summit, where she received a standing ovation for a speech to the delegates. The group also addressed delegates at the United Nations Conference on Environment and Development (UNCED).
The following is the video of her speech back in 1992.
More info about Severn can be found here:
http://www.slothclub.org/pages/activity/japan/sevtour/sevbiography.htm
http://www.thegreatwarming.com/localhero-interviewsevernsuzuki.html