Climate-related risks: Implications for municipal governments in Brazil

Climate-related urban risks are intensifying in Brazilian metropolitan areas, where socio-environmental inequalities and fragmented urbanisation shape uneven exposure and vulnerability. In Brazil, municipalities occupy a central place in responding to these risks within a federal legal framework that distributes responsibilities across multiple sectors and levels of government. This paper examines how key federal legal frameworks assign municipalities responsibilities related to the built environment and climate-risk governance, and what this implies for local implementation. The analysis combines a documentary review of federal laws with semi-structured interviews and documentary data from the Greater ABC (GABC), a metropolitan sub-region of São Paulo. The findings show that municipalities are assigned overlapping regulatory, operational and coordinating responsibilities across policies that converge in the same municipal territory, producing a municipal legal overload. The GABC case shows that persistent vulnerabilities in risk-prone areas challenge the translation of legal responsibilities into effective risk reduction even where institutional conditions are comparatively stronger than the national average. It is found that municipal centrality in climate-risk governance is not self-executing: the promotion of federal mandates without coordination mechanisms and support for local capacity is unlikely to produce structural changes in the unequal distribution of vulnerability across municipalities. POLICY RELEVANCE Brazil's federal legal framework places municipalities at the centre of climate adaptation and urban disaster risk management. In practice, local governments are expected to regulate land use, organise core urban services, protect environmentally sensitive areas and act as first responders in situations of risk. However, these responsibilities are implemented under highly uneven institutional and technical conditions, and with limited routine support for intersectoral and intergovernmental coordination. In metropolitan contexts such as the GABC, this concentration of mandates places demands on local governments whose capacity to manage them varies substantially, making effective risk reduction dependent on coordination across sectors and jurisdictions. Policymakers should therefore focus not only on assigning responsibilities but also on creating the enabling conditions for implementation, including more stable support, stronger coordination mechanisms and greater sensitivity to territorial inequalities between municipalities.