The environmental movements that emerged after the 1972 Stockholm Convention, inspired Brazilian Constitution that elevated the ecologically balanced environment to the level of fundamental rights. Concomitantly, by converting it into a common good, it imposed on everyone the duty to protect and preserve it, even for generations to come. Thus, through jurisprudential research, the objective of the article is to analyze the STJ's understanding of the environment. It concludes that the decisions of the STJ are based on a rationality not converging in relation to the ideals of an ecologically balanced environment and sustainable development.