In March 1985 Aridjis founded and became president of the Group of 100, an association of prominent artists and intellectuals, including Octavio Paz, Juan Rulfo, Rufino Tamayo, Gabriel García Márquez, Álvaro Mutis, Augusto Monterroso, Francisco Toledo, Leonora Carrington, Mathias Goeritz, Manuel Álvarez Bravo, Elena Poniatowska and others, devoted to environmental protection and the defense of biodiversity in Mexico and Latin America. Under his leadership the Group of 100 achieved in 1986 the official decree ensuring protection for the forests where the migratory monarch butterfly overwinters and in 1990 a permanent ban on the capture and commercialization of all seven species of sea turtle in Mexico.
In March 1985, Aridjis established and became president of the Group of 100, an association of prominent artists and intellectuals dedicated to environmental protection and biodiversity preservation in Mexico and Latin America. Under his leadership, the group achieved official decrees protecting forests where monarch butterflies overwinter and a ban on capturing and commercializing sea turtles in Mexico.