The relation to knowledge is at the same time the relationship of a subject to the world, to oneself and to others (Charlot, 1997). It is a particularly fruitful concept in Education for Sustainable Development (ESD) as it allows us to study the relationship of meaning and value conferred on knowledge and to understand how young people engage in school and in society when it comes to environment and sustainable development (SD). As part of a study that aims to analyze relationships with knowledge, the territories of high school youth, knowledge assessments were conducted by 597 students in two Quebec schools and three French schools. The lexical analysis as well as a content analysis made it possible to identify the significant learnings identified by these young people concerning the environment and the SD as well as the people and the places which they associate there. Contrasting learning experiences between France and Quebec emerge, themselves related to the curricular choices of these two educational systems. If the apprenticeships of young Quebecers seem more diversified, with a more marked use of the Internet, those of French students are a little less. In both countries, the epistemic relationship appears to be central. These results lead to proposals for a critical and reflective ESD enriching the treatment of these problems in schools. Contrasting learning experiences between France and Quebec emerge, themselves related to the curricular choices of these two educational systems. If the apprenticeships of young Quebecers seem more diversified, with a more marked use of the Internet, those of French students are a little less. In both countries, the epistemic relationship appears to be central. These results lead to proposals for a critical and reflective ESD enriching the treatment of these problems in schools. Contrasting learning experiences between France and Quebec emerge, themselves related to the curricular choices of these two educational systems. If the apprenticeships of young Quebecers seem more diversified, with a more marked use of the Internet, those of French students are a little less. In both countries, the epistemic relationship appears to be central. These results lead to proposals for a critical and reflective ESD enriching the treatment of these problems in schools. The relationship to knowledge is both a relationship to the world, the self and the others (Charlot, 1997). Is a key issue in education for sustainable development (ESD), since it Allows to study the relationship of meaning and value conferred to knowledge and to Identify how young people engaged in school and in society Relating environmental and sustainable development (SD) issues. As part of a study that seeks to analyze the relationships of knowledge and territories of young people of secondary schools, some knowledge assessments were completed by 597 students in two schools from Quebec and three schools from France. Bearing on the subject of some lexical analysis, we discuss some of the issues that are related to environmental issues. These analyzes reveal some contrasted learning experiences between France and Quebec, related to curricular choices specific to each educational system. While young Quebecers show more diverse learning items, Those of French students are less so. In both countries, the epistemic dimension emerges as central. These results lead to a more critical and reflexive ESD, which enriched the teaching of these issues at school. [ABSTRACT FROM AUTHOR]