In the following document, the research about the study case of the Model United Nations (MUN) in a group of students of the Master's Degree in Education: Environment Education Field (MECEA) of the National Pedagogy University (UPN) Mexicali is presented. This research is relevant for the education study field, specifically from a constructivist approach and from the critical pedagogy, because it is analyzed the importance of MUN as a pedagogic tool to foster knowledge and capabilities in the students, developing a critical consciousness. The research has been conducted entirely with a qualitative focus of study case with an ethnographic method, including instruments as participatory observation, semi-structured interviews and field journal. The main findings reached are that in the study case analyzed, MUNs have shown to be a useful pedagogic tool to foster and practice knowledge about environmental education, environmental impact, international cooperation, the 2030 agenda, as well as necessary capabilities for an environmental educator, such as negotiation, public speaking, formal language and debate. Aspects of the MUN like roleplaying Zone of Proximal Development (ZPD) and the interactions between participants in a diplomatic frame have proven to be crucial for the results that these exercises foster in the participants.
