In early September 2019, dense crude oil began to wash the beaches of Brazil's tropical coast. Four months after the first report, the oil has already been found along >3000 km of the Brazilian coastline on >980 beaches and was recently observed along the Amazon coast, making this oil spill the most extensive and severe environmental disaster ever recorded in Brazilian history, in the South Atlantic basin, and in tropical coastal regions worldwide. Four features of this oil-spill disaster make it unique: 1) the characteristics of the oil spill; 2) the characteristics of the affected region in tropical Brazil; 3) the significant number of protected areas (>55) and tropical ecosystems affected by the oil; and 4) the absence of measures and/or flaws in the measures taken by the federal government to address this environmental and social emergency. The affected species and poor human communities in Brazil should receive focused attention in the coming decades owing to the long-term impacts of the oil contamination. Environmental monitoring and response measures must be implemented to minimize the ecological, economic, and social effects of the spill. Biodiversity and climate regulation losses considering blue carbon environments should drive discussions regarding mining accidents and global consequences related to pre-salt oil exploitation, new spill events, and their global impacts. These measures are particularly relevant in areas with high tropical biodiversity and high social inequality, as in the present case, which represents one of the worst-case scenarios of an environmental and governmental disaster.