Environmentalists hail decline but warn weakened laws could reverse gains Brazil’s Atlantic forest, the country’s most threatened biome, last year recorded its lowest level of deforestation since monitoring began 40 years ago, a new report shows. The forest is Brazil’s most populous biome, and home to 80% of the population and major cities such as Rio de Janeiro and São Paulo. In 2025 it recorded 8,658 hectares of deforestation, marking the first time it has fallen below 10,000 hectares since 19