Sustainable development makes governments responsible for environmental quality. Failure to implement environmental standards by government institutions can lead to irreparable damages. This study examines the civil liability of the Iranian and French governments for such failure, using a descriptive-analytical method and a comparative approach. In the French legal system, the concept of “state error” and the evolution of the judicial practice of the Council of State, especially in cases such as the “Grand-Sainte case”, have created a progressive framework for the government’s commitment to climate and environmental measures. In contrast, in Iranian law, despite numerous laws such as the “Environmental Protection and Improvement Law” and the “Clean Air Law”, the civil liability of the government is mainly based on the general rules of civil liability (Articles 1 to 10 of the Civil Liability Law of 1339) and Article 171 of the Constitution, which faces challenges in proving the causal relationship and the lack of specialized judicial practice. The findings show that the French legal system has achieved better protection of citizens' rights by accepting "no-fault liability" in dangerous areas and positive state obligations. The study emphasizes that the civil liability of the state in this area is not only a tool for compensation, but also a lever for ensuring intergenerational justice.