In response to the socio-ecological crisis, popular education organizations have broadened their fields of intervention to include the development of critical eco-citizenship. Because of their precarious situation, often marginalized, low-income adults are generally neglected by environmental education programs or initiatives, despite a growing interest on their part for environmental issues. The question then arises as to how to reach these adults on such issues, who, marked by an often negative school experience (failures, dropouts, humiliation), have a low level of education and struggle on a daily basis to meet their basic needs? This article describes an interdisciplinary pedagogical initiative that combines environmental education and literacy.