Leonard was born in Seattle, Washington in 1964. During the 1970s, Leonard’s childhood was filled with family camping trips in the mountains. During these trips, she noticed the forests becoming smaller and wondered why this was happening. As an adult, Leonard enrolled in an environmental studies degree program at Barnard College. There, she noticed that most of the garbage on the streets was made of paper, seemingly answering her childhood question of where all the forests are going. Her curiosity to learn more about waste and its destination led her to the Fresh Kills Landfill in Staten Island, which was once one of the largest landfills in the world. This started her 20-year project on waste research, to discover the origins of the waste system and why we waste so much today.

Leonard holds an undergraduate degree from Barnard College, Columbia University and a graduate degree in regional and city planning from Cornell University. She is the Executive Director of Greenpeace USA. Leonard began her career at Greenpeace working on a campaign to ban international waste dumping. Her animated film, The Story of Stuff (2007), is a critique of consumerism that promotes sustainability. She lives in Berkeley, California.