Summary:
50 members of the parliament petitioned the Hungarian Constitutional Court to declare several provisions of the Climate Protection Act XLIV of 2020 as unconstitutional. They argued that the Act was not in conformity with the following provisions of the Fundamental Law of Hungary: Article P(1) containing the obligation of the state and everyone to protect, maintain land, and preserve for future generations, Hungary’s forests and the reserves of water; biodiversity; and cultural artefacts; Article Q(2) containing the obligation to ensure that Hungarian law is in conformity with international law; Article B(1) the obligation to conform to the requirements of rule of law, and the fundamental rights to life, physical health and well-being, legal protection for homes under Articles II, XX and XXI(1) respectively.
In its plenary session on 13 May 2025, the Constitutional Court announced its decision on the case. It held that Section 3(1) of the Climate Protection Act, establishing a 40% emission reduction target to be achieved by 2030 (compared to 1990 levels), was unconstitutional and repealed with effect from 30 June 2026. In its reasoning, the Court invoked the principles of non-regression, precaution and prevention as bases for interpreting obligations under Articles P(1), XX(1) and XXI(1) of the Fundamental Law which required the state to continuously improve the level of protection in light of the latest developments in climate science and technology. It characterized the maintenance of the 40% target as a failure to update the state’s mitigation commitments in light of ‘events’ which had rendered it outdated. Further, it found that the Climate Protection Act only contained emissions reduction obligations, and did not address the creation of emissions sinks and adoption of adaptation measures, which are of equal importance in ensuring the effectiveness of the legal framework for protection against climate-related risks.
The Constitutional Court also found that the lack of mechanisms for ensuring accountability for the achievement of the target prescribed in Article 3(1) of the Climate Protection Act, to be a reason as to why the provision formally ran afoul of Article B(1) (rule of law) and in terms of content, led to a violation of Articles P(1), XX(1) and XXI(1) of the Fundamental Law.
The Court thus ordered the National Assembly to adopt a comprehensive regulation on Hungary’s climate mitigation commitment as well as adaptation measures tailored to Hungary’s circumstances by 30 June 2026.
Status:
The decision is final
Suggested Citation,
Constitutional Court of Hungary, Constitutionality of Article 3(1) of the Climate Protection Act (Hungary), Decision No. II/3536/2021, 13 May 2025.
Links:
Unofficial version of the decision of the Hungarian Constitutional Court (in Hungarian) can be found here.
Last updated: 12 March 2026