Cortez-Riggo (2011) used an environment-focused project called “Green Project” as one way to implement global citizenship education in U.S. middle schools. The “Green Project” incorporated multidisciplinary activities into the curriculum to show how students transform to become agents of social change, active protectors of the earth, and citizens of the world, through the pedagogical view of Freire. This project, including the subjects of science, mathematics, social studies, and English language arts, lasted for five months and it was held three days a week. The students had to categorize if these projects would impact the communities locally, nationally, or globally.