São Paulo, Brazil

São Paulo is one of Brazil’s most economically productive and technologically advanced metropolises. Lying in the midst of a coastal mountain range but close to the coast, the megacity might not be prone to the worst aspects of coastal flooding, but it inherits significant challenges from a century of modern urbanization and efforts to contain its powerful river systems. This chapter examines the complex and multifaceted character of southeastern Brazil’s climate system, including variability, showing the importance of flooding and droughts in population flux and urban water crisis. Discussing recent efforts, such as piscinões, to promote adaptive water management, it indicates that some major financial investments and adjustments are needed to bring down the perennial costs of flooding and drought, as well as their implications for São Paulo’s poorest residents.