Brazil is home to a vast portion of the planet’s biodiversity, encompassing globally significant biomes like the Amazon rainforest and the Pantanal wetlands. The nation is classified as the world’s most megadiverse country, hosting an estimated 15% to 20% of the world’s total biological diversity. This immense natural heritage is currently under considerable pressure from human activities, creating significant environmental challenges. The degradation of its natural systems has widespread implications for global climate stability and biodiversity.
Deforestation and Land Use Transformation
Land use change, primarily deforestation, represents the largest driver of environmental degradation in Brazil. The Amazon and the Cerrado savanna are the biomes most heavily affected by this conversion, which is driven largely by agricultural expansion. Beef production and soy cultivation are the dominant economic forces behind this habitat loss. Cattle ranching is the top driver of this destruction in tropical forests, often clearing land later converted to soy production, which primarily serves as livestock feed for global markets.
The Cerrado, the world’s most biodiverse savanna, has seen immense losses due to its flat topography and suitability for mechanized agriculture. Over the past four decades, the biome has lost approximately 40.5 million hectares, equivalent to 28% of its native vegetation. Soy cultivation in the Cerrado increased by over 500% between 1985 and 2024, concentrating in regions like Matopiba, where agribusiness replaces native cover. This destruction threatens the Cerrado’s ability to function as a headwaters region, supplying water to three major Brazilian river basins.
The Amazon rainforest faces reaching a “tipping point,” a threshold beyond which the ecosystem could undergo an irreversible shift to a drier, savanna-like state. This collapse is projected to affect up to half of the forest by 2050, primarily due to the compounding stressors of deforestation and climate change. Forest loss reduces the Amazon’s ability to recycle moisture, which in turn leads to drier conditions and increased vulnerability to fires. As a result of past land-use changes, the Brazilian Amazon has already transitioned from acting as a net carbon sink to an overall carbon source, releasing stored carbon into the atmosphere.
Threats to Brazil’s Other Ecosystems
Beyond the Amazon, other biomes face intense threats, particularly the Atlantic Forest and the Pantanal wetlands. The Atlantic Forest (Mata Atlântica) is a global biodiversity hotspot that once stretched along Brazil’s coast but has been reduced to a fraction of its original extent. Centuries of human occupation, driven by agriculture and urbanization, have left less than 12% of the original forest cover remaining, mostly in small, fragmented patches.
This fragmentation profoundly impacts the forest’s biological richness, which includes endemism rates of approximately 40% for vascular plants and 90% for amphibians. A study on the forest’s tree species found that 82% of those found only in the Atlantic Forest are threatened with extinction. This remaining forest is under continuous pressure from cattle ranching, sugarcane and coffee plantations, and the sprawl of major metropolitan areas like Rio de Janeiro and São Paulo.
The Pantanal, the world’s largest tropical wetland, is threatened by hydrological disruption and contamination from upstream agricultural practices. The seasonal flood pulse that defines the wetland is increasingly disrupted by the construction of dams for hydroelectricity and the siphoning of water for irrigation. Runoff from intensive soy farming and cattle ranching in the surrounding highlands washes agrochemicals and sediment into the Pantanal’s waterways. This influx can lead to a 200% increase in sediment deposits, which reduces water levels and disrupts the flood pulse that sustains the ecosystem.
Pollution from Resource Extraction and Urbanization
Contamination from industrial activity and poor urban infrastructure represents a widespread threat to human and ecosystem health. Illegal gold mining in the Amazon is a significant source of mercury contamination in river systems, as the element is used to separate gold from sediment. This mercury is then transformed into methylmercury by bacteria in the water, which accumulates in the fish that form a staple part of the local diet, particularly for indigenous communities.
In the Yanomami Indigenous Territory, for example, studies have shown that community members have mercury contamination levels that exceed safe limits. Exposure to this neurotoxin can lead to severe health issues, including neurological damage and developmental abnormalities in unborn children. The contamination also degrades the ecosystem, driving away animals and making cultivation unfeasible.
Urban areas, where nearly 87% of Brazil’s population resides, struggle with inadequate sanitation infrastructure and waste management. Approximately 42% of urban residents lack access to proper sanitation and sewage facilities. This deficiency results in the widespread discharge of untreated sewage directly into rivers and coastal waters, causing contamination and increasing the risk of waterborne diseases. Furthermore, a significant portion of solid waste is disposed of improperly in open dumps or inadequate landfills, leading to environmental and public health problems.