Popular health surveillance in the face of climate emergencies

Public health emergencies associated with extreme weather events - such as floods and droughts - have intensified, revealing the complex relationship between climate emergencies and structural inequalities. In Brazil, rural populations, riverine and forest communities, Indigenous peoples and those living in urban peripheries are disproportionately exposed to the impacts of climate emergencies, which exacerbate socio-environmental vulnerabilities. To protect populations, community-driven initiatives known as "Popular Health Surveillance" (PHS) have emerged and gained political relevance. PHS integrates popular knowledge, scientific understanding, and perspectives from health systems. Anchored in the principles of Popular Education in Health, the ecology of knowledge, and the Social Determination of Health and Good Living (Bien Vivir), PHS recognizes, values, and combines scientific knowledge, popular knowledge, and territorial experiences, promoting intercultural dialogue as a core methodological approach. In the context of climate emergencies, a major challenge for health systems is the implementation of effective mitigation, prevention, and resilience strategies - efforts that require coordination and collaboration among multiple actors and meaningful participation of populations in higher-risk areas. This article presents a conceptual framework and approaches for implementing Popular Health Surveillance in the context of climate emergencies. A documentary study identified national and international experiences of participatory health surveillance and examined them in dialogue with the PHS proposal. These experiences were analyzed based on their definitions and main operational strategies. PHS was further examined through its theoretical principles, strategies, attributes, and application in the face of climate emergencies. PHS is not only a participatory monitoring tool, but a strategy for promoting socio-environmental, cognitive, and health justice. In the context of intensifying climate crises, this approach is essential strengthening community adaptive capacity, integrating diverse knowledge systems, and demanding more inclusive and democratic public policies from an emancipatory perspective.