Abstract
The current study assessed the curriculum and subjects used in high schools in different countries in teaching environmental issues. The study reviewed current policy, curriculum, delivery and challenges associated with the implementation of the policies associated with teaching Environmental Education in high schools. A systematic review approach of peer-reviewed journals between 2003 and 2023 involving Environmental Education only in High Schools was used. The review showed that EE is included in the curricula of most of the high schools from different countries but with low visibility and implementation strategies. Currently, EE does not stand alone as a subject but is housed in different subjects and mostly taught in science subjects (Geography and Biology) in high schools. Students in arts and social sciences classes have little exposure to EE. The review further showed that teachers' attitudes and knowledge of environmental issues remain a major setback in the teachings of the subject. Lack of infrastructure, time and teachers' availability are other factors affecting EE at high school. Clear direction is needed for the implementation of the EE in High Schools. A subject that teaches EE as a subject may be considered so that it is not viewed as a supporting subject by the students.