Environmental law in Mercosur is a strategic component to promote a sustainable development model that contemplates economic integration and the preservation of natural resources shared among member countries in the face of the climate crises we are currently facing. This article seeks to analyze regional integration in Mercosur from the perspective of environmental law, with a focus on climate change and water resources management in Argentina. Thus, in order to achieve the proposed objectives, it is necessary to analyze Environmental Law within the scope of Mercosur, that is, to recognize its advances, challenges and opportunities. In addition, check the regulatory frameworks available in this context and the main legal measures currently adopted. And, finally, to verify the importance and need for environmental risk management in the meantime. The research seeks to offer paths and reflections for the strengthening of regional environmental governance, and the creation of binding mechanisms for the application of standards, in order to ensure the environmental and economic resilience of the region. The methodology adopted to achieve the objectives was descriptive-interpretative, based on doctrinal sources, national and international legislation.