Seven principles for a critical transdisciplinary approach to planetary health.

The ecological, social, and health crises of the Anthropocene demand approaches to knowledge that confront complexity, uncertainty, and structural injustice. Transdisciplinarity is an approach that can transcend disciplinary silos by integrating academic and non-academic knowledge. Yet, action on public health, planetary health, and health inequities is often implemented in technocratic, depoliticised, and tokenistic ways. Such practices risk marginalising lived experience, reinforcing epistemic hierarchies, and overlooking structural drivers such as capitalism, colonialism, and patriarchy. Drawing on examples from the exposome, One Health, and planetary health paradigms, we argue that current applications of transdisciplinarity privilege biomedical or technical framings, underplay systemic power relations, and fail to deliver transformative impact. A critical transdisciplinary approach is needed-one that is political, reflexive, justice oriented, and grounded in collaboration with affected communities, social movements, and practitioners. It should integrate diverse knowledge systems, value experiential and Indigenous perspectives, and align research with agendas for structural change. We propose seven guiding principles. The approach should be: critical, systemic, structural, sociohistorical, democratic, timely, and transformative. Advancing planetary health equity requires more than an understanding of the systemic determinants of disease and environmental degradation-it requires dismantling the political, economic, and cultural systems that perpetuate them. A critical transdisciplinary approach that follows these principles can guide research, policy, and practice, positioning knowledge not only as a tool for explanation but also as an instrument for transformation.