Brazil is experiencing a severe environmental crisis, which culminates with the dismantling of the National Environmental Policy. The recent changes carried out since 2019 by the Brazilian government have been widely reflected negatively in the national and international scientific communities, bringing to light the importance of Brazilian biomes for the sustainable development. This article aimed to investigate and reflect on the encounters and disagreements of Law no. 6,938, of August 31, 1981, discussing the current National Environmental Policy. For this, exploratory research with a qualitative approach was carried out, based on a literature review. Data analysis was performed using the complex-systemic approach method. The results indicate that there was a denaturation of the National Environmental Policy, thus making the law ineffective for the preservation of Brazil's environmental heritage. [ABSTRACT FROM AUTHOR]