She has spoken around the world about environmental issues, urging listeners to define their values, act with the future in mind and take individual responsibility.

[4] In 1992, at age 12, Cullis-Suzuki raised money with members of ECO to attend the Earth Summit in Rio de Janeiro.

Along with group members Michelle Quigg, Vanessa Suttie, and Morgan Geisler, Cullis-Suzuki presented environmental issues from a youth perspective at the summit, where she was applauded for a speech to the delegates.

Cullis-Suzuki co-hosted Suzuki's Nature Quest, a children's television series that aired on Discovery Kids in 2002.

[10] Cullis-Suzuki is the main character in the documentary film Severn, the Voice of Our Children, directed by Jean-Paul Jaud and released theatrically in France on November 10, 2010.

[11][12] She moved to Vancouver, BC in order to start her new role as the Executive Director of the David Suzuki Foundation, which she began in September 2021.

In 2020, more than 20 animation directors, under the artistic supervision of Simone Giampaolo, transposed her speech into a short film named Only a Child, which they describe as "a visual poem".