The omission of epistemologies from the Global South inhibits holistic pedagogical approaches for effective sustainability teaching and learning. Employing the theoretical lens of ecology of knowledges, the structures and dynamics that frame and constrain sustainability education in higher education were critiqued. Six constraints of environmental sustainability pedagogies were also deconstructed: epistemic inequity, globalisation, neoliberalism, pedagogical incompatibility, anthropocentrism, and social inequity. Consequently, ideas for justice-based environmental sustainability were proffered, especially for eco-justice and epistemic justice. The need for sustainability education to be relevant, relatable, critical, holistic, inclusive, and transformational was also argued. Key contributions of this paper are a compilation of constraints on sustainability pedagogies, demonstration of the relationship between the usually isolated constraints around teaching and learning about sustainability in higher education, and the application of the theory of the ecology of knowledges to the deconstruction of these constraints. These contributions have implications for achieving justice-based sustainability in higher education.