Severn Cullis-Suzuki was a 12-year-old student activist when she addressed world delegates at the UN Earth Summit in 1992, imploring leaders to consider future generations while negotiating.
She is returning to the Rio+20 conference this year and filmed a short message for our colleagues at Green Cross International. "I will be there again, this time as a mother," she says. "My perspective has shifted, but my message has not. Today we are even more desperate for transformative change. We now live in a world where over 50 percent of the global population is under the age of 30. We have to change to a more long-term focus, a more long-term value system..." Her full message in the clip above.