The prevalence of habitat and life-threatening environmental problems has motivated environmental researchers to develop education programs to strengthen students' environmental literacy. We argue that the connection between environmental literacy and metacognition is theoretically promising. Therefore, we developed the "Meta-CIC" model, which is designed to develop students' environmental literacy, in parallel to supporting their metacognition. The core of this model is open inquiry-based learning. An explicit environmentally focused metacognitive guidance ("Meta") was embedded within the inquiry setting. This guidance referred to the components of metacognition and the strands of environmental literacy. The model includes two levels of collaboration: the "Collaborating Inquiry" (CI), which refers to the interactions between a pair of students working on an inquiry project; and the "Collaborating Inquiry Community" (CIC), which refers to the interactions among pairs of students working on different projects. We investigated the contribution of the "Meta"-CIC model to students' expression of environmental literacy. For this purpose, 250 seventh and eight grade students, who conducted open inquiry projects throughout a full school year, participated in this research. We examined students' environmental literacy using two tools: an environmental literacy questionnaire, which adopts a positivist, outcome-based approach; and an innovative Environmental Literacy INventory (ELIN), which adopts a phenomenological process-based approach. The environmental literacy questionnaire served as pre- and post-test measurements. The ELIN was used to analyze students' reflections, following their involvement in the inquiry process. The results of this study provide supporting evidence for the theoretical relationship between metacognition and environmental literacy, and demonstrate the different effects of the "Meta" and the "CIC" components on students' expressions of environmental literacy. The results also point to the importance of providing explicit and context-based metacognitive support. This study highlights the importance of developing students' high order thinking and implementing the "Meta-CIC" model, within the framework of environmental education.