Decision of the Hungarian Constitutional Court in case II/3536/2021 (on the constitutionality of Article 3(1) of the Climate Protection Act)

The constitutional review case of Hungary’s Climate Protection Act (Act XLIV of 2020) was initiated by fifty members of Parliament, who argued that several provisions of the Act violated the Hungarian Fundamental Law (Alaptörvény) and certain international treaties, including the Paris Agreement and the UN Framework Convention on Climate Change (UNFCCC). The petitioners submitted their application in 2021 (case no. II/3536/2021), challenging, among other things, the emission reduction targets laid out in Article 3(1) of the Act. They argued that the Act’s 2030 target—a 40% reduction in greenhouse gas (GHG) emissions compared to 1990 levels—was insufficient, fell short of both European Union commitments (which call for at least 55% reductions), and failed to align with the scientific consensus necessary to meet the Paris Agreement’s 1.5°C temperature goal. They also claimed that the Act lacked concrete implementation measures and disregarded principles such as precaution and intergenerational equity. The Constitutional Court found that Article 3(1) of the Climate Protection Act was unconstitutional. Specifically, the Court held that the provision violated Article P(1), Article XX(1), and Article XXI(1) of the Fundamental Law, which enshrine the principles of intergenerational justice, the right to physical and mental health, and the right to a healthy environment. The Court emphasized that the emission target failed to uphold the constitutional duty to preserve natural resources for future generations and to take adequate preventive and precautionary action against foreseeable climate risks. The Court did not accept the argument that this provision conflicted with international treaties, including the Paris Agreement. However, it emphasized the state's duty to take climate measures that align with Hungary's constitutional obligations and broader international climate goals. On June 12, 2025, the Court ruled that Article 3(1) of the Climate Protection Act is unconstitutional and annulled it, effective June 30, 2026. This delayed annulment gives the legislature time to revise the law. Additionally, the Court determined—acting ex officio—that Parliament committed a constitutional omission by failing to adopt comprehensive, climate-specific measures tailored to Hungary’s and the Carpathian Basin’s needs. These include not only mitigation (beyond traditional emissions regulation) but also adaptation and resilience measures. The Court ordered Parliament to fulfill this legislative obligation by June 30, 2026. The Court dismissed or rejected other parts of the petition, including challenges to Articles 1, 2, 3(2)-(3), and 4 of the Act, either for lack of legal merit or procedural insufficiency. In sum, this decision is a landmark ruling in Hungarian climate law. It enforces constitutional obligations related to environmental protection and intergenerational equity and requires the legislature to adopt more ambitious and specific climate policies in line with constitutional principles.