In February 2025, the South Korean government promised a long-term plan to achieve carbon neutrality by 2050, whereas previous plans were limited to 2030. In this post, I examine how a court case considering the United Nations (UN) Framework Convention on Climate Change influenced this shift. The Constitutional Court’s ruling in D.H. Kim et al v Korea on 29 August 2024, made while I was in South Korea, marked a historic decision. I explain that the judges creatively linked the constitutional principle of ‘statutory reservation’ to the international environmental law principle of intergenerational equity.
The Case and its Context
South Korea’s climate case began in 2020 when a group of 19 young South Koreans filed a constitutional complaint against the government’s climate policies. One of the claimants was only a foetus at the time of the filing. The claimants later added extra complaints, and their case was ultimately consolidated with three other cases by the Constitutional Court in a decision made on 19 February 2024 (2020HunMa389, 2021HunMa1264, 2022HunMa854 and 2023HunMa846). The most substantial argument of D.H. Kim et al v Korea turned out to be that the government’s climate targets were insufficient and lacked concrete measures for emissions reductions beyond 2030, despite South Korea’s commitment to carbon neutrality by 2050. In so doing, the burden of climate action was shifted onto future generations, thereby infringing on their constitutional right to a healthy and pleasant environment.
At the heart of the case was the Framework Act on Carbon Neutrality and Green Growth for Coping with Climate Crisis (‘Carbon Neutrality Framework Act’), first introduced in 2010 and later revised to align with the Paris Agreement’s goal of pursuing efforts to limit global warming to 1.5°C above pre-industrial levels. This Agreement was adopted in 2015 under the 1994 UN Framework Convention on Climate Change (UNFCCC). Under the Paris Agreement, South Korea, like other signatories, committed to reducing greenhouse gas emissions through nationally determined contributions. These contributions typically focus on short- to medium-term targets (e.g., 2030), but they are also expected to align with the long-term objective of achieving net-zero emissions by 2050 to limit warming to 1.5°C. However, these international targets were not legally binding under the Agreement.
The South Korean Constitutional Court’s ruling of 29 August 2024 addressed Article 8, Section 1 of the Carbon Neutrality Framework Act which prescribes that the government shall set ‘a national mid- and long-term greenhouse gas reduction target’ ‘to reduce national greenhouse gas emissions by a ratio prescribed by Presidential Decree not less than 35 percent from the 2018 level by 2030’. Article 3, Section 1 of the Decree prescribes that ratio as 40 percent. These targets, a core element of South Korea’s nationally determined contributions under the Paris Agreement, were submitted and registered with the UNFCCC Secretariat in 2021.
The key issue was whether the greenhouse gas reduction targets set by the aforementioned provisions and plans infringe upon complainants’ right to live in a healthy and pleasant environment, as outlined in Article 35 of South Korea’s Constitution (1948). The complainants argued that the targets and plans excessively shift the burden of reduction onto future generations. Other rights—including the right to life and the right to pursue happiness—were also mentioned by the claimants, but the Court considered it was sufficient to consider the right to a healthy and pleasant environment.
The Constitutional Court unanimously ruled in favour of the plaintiffs on this point, agreeing that the absence of clear emissions reduction targets beyond 2030 violated Article 35 of the Constitution. The lack of legally binding measures to reduce emissions between 2030 and 2049 placed an excessive burden on future generations.
The Court explained that two principles in South Korean constitutional law were violated by Article 8, Section 1 of the Carbon Neutrality Framework Act. These were the principle of ‘prohibition of insufficient protection’ and the principle of ‘statutory reservation’. The Court directly referred to international law to assess both principles. This was rather exceptional, as the Court usually prefers to incorporate international law as interpretative tools.
First, the constitutional principle of ‘prohibition of insufficient protection’ means that the legislature and executive powers should provide appropriate and enough protective measures at a minimum. As is often the case in court cases on positive obligations, the Court emphasized that it has limited power but that it can assess whether sufficient measures have been taken. To do so, the Court accounted for ‘international standards’ and ‘scientific facts’. The Court referred to UNFCCC, the Paris Agreement and other relevant international standards. For its consideration of scientific analyses and forecasts concerning greenhouse gas reductions, the Court also relied upon international institutions, notably the Intergovernmental Panel on Climate Change’s reports, created under the joint auspices of the UN Environment Programme and the World Meteorological Organization.
Second, the constitutional principle of ‘statutory reservation’, which includes the principle of ‘parliamentary reservation’ was considered. Article 35 of the Constitution explicitly refers to this principle, noting that ‘the substance and exercise of the environmental right shall be determined by law’. The Court stressed that this principle goes further than requiring a legal basis for administrative actions. Rather, in any matters of fundamental significance to the South Korean community and its members, in particular their fundamental rights, such decisions must be determined by the legislature, and not the executive. This safeguards democratic values, enabling criticism and participation from the general public and opposing parties.
The Court then highlighted that future generations, who will endure the most significant consequences of the climate crisis, are excluded from the present democratic political process under the principle of statutory reservation. In light of this, legislators have a heightened obligation and responsibility to enact more specific legislation concerning mid- to long-term greenhouse gas reduction plans.
In all other respects, the complaints were rejected. The Court did also not declare the Carbon Neutrality Framework Act ‘unconstitutional’ ensuring that the 2030 target would remain valid. Rather, the Court declared this Act ‘not conform’ the constitution to remain temporarily valid while requiring legislative correction.
On the day of the judgment, the South Korean Ministry of Environment issued a statement stressing it would respect the Court’s decision. In February 2025, Environment Minister Kim Wan-seop expressed his hope to rename the Ministry to the Ministry of Climate and Environment. While the government, under the former acting President Choi Sang-mok, promised to submit its greenhouse gas goal for 2035 to the UNFCCC Secretariat by October 2025, it also announced its ambition to design a long-term plan to achieve carbon neutrality by 2050. The Carbon Neutrality Framework Act would need to be amended accordingly by March 2026, a deadline set by the Constitutional Court.
Key Legal Principles and International Law
The South Korean Constitutional Court’s emphasis on protecting the rights of future generations reflects broader international environmental law principles, particularly regarding intergenerational equity. The Brundtland Report ‘Our common future’ (1987) famously stressed that the needs of present generations should not compromise the ability of future generations to meet their own needs. The International Court of Justice’s 1996 Nuclear Weapons Advisory Opinion also indicated that the environment is ‘the living space, the quality of life and the very health of human beings, including generations unborn.’
What is more, the South Korean Constitutional Court’s decision is part of a broader global trend where courts increasingly connect climate change and human rights. Such cases—facilitated by transnational advocacy networks such as the Climate Litigation Network—fill voids left by international agreements. The UN General Assembly recognised the right to a clean, healthy and sustainable environment in 2022, but the UN Security Council has not yet considered climate change as a threat to peace, breach of the peace, or act of aggression under article 39 of the UN Charter. The UN General Assembly then also turned to a court, the ICJ, for an advisory opinion on state obligation in respect of climate change, expected to be delivered in 2025.
The national court cases are groundbreaking because they do not allow one country to point fingers at other countries for a global problem. Such cases do not see the difficulties of drawing a causal link between states’ acts and omissions as insurmountable. As the South Korean Constitutional Court noted in 2024, ‘if a country neglects its greenhouse gas reduction efforts, claiming the difficulty of addressing the global climate crisis solely through its own measures, or pointing to the insufficient efforts of other nations, this would result in inadequate greenhouse gas reduction efforts across all countries’.
Famously, in 2019, the Dutch Supreme Court agreed with the Urgenda foundation that the Netherlands has an obligation to reduce greenhouse gasses with 25 percent before the end of 2020 compared to 1990 levels (19/00135). This was required under the right to protect life and the right to respect for private life and home in Articles 2 and 8 of the European Convention on Human Rights (1950). In 2024, the European Court of Human Rights also ruled in Verein KlimaSeniorinnen Schweiz et al v. Switzerland that Switzerland violated the right to protect Article 8 of the Convention (53600/20). A striking difference with the Korean case is that the European Court was only willing to hear a climate claim from an organisation and not from individual claimants, while the South Korean Constitutional Court was willing to hear a case co-filed by a foetus. Arguably the South Korean approach emphasised the direct impact of climate change on the fundamental rights of the youngest and future generations, thereby strengthening the argument that their constitutional rights are at risk.
The South Korean Court’s recent ruling closely mirrors the 2021 decision by Germany’s Federal Constitutional Court in Neubauer et al. v. Germany (2656/18, 288/20, 96/20 and 78/20).The resemblance between the two rulings is not coincidental, as South Korea’s legal system is heavily influenced by the German-style continental system, adopted during the period of Japanese occupation. The German case also stemmed from a constitutional complaint filed by young individuals, who argued that Germany’s Climate Protection Act of 2019 fell short in addressing climate change and safeguarding their constitutional right. The German Court found that the Act violated Article 20a of the German Constitution (1949), which obligates the state to protect the natural foundations of life for current and future generations, in accordance with law and justice. Specifically, the German Court ruled that the Act’s insufficient provisions for emissions reductions beyond 2030 shifted an undue burden onto future generations, thereby breaching the principle of intergenerational equity. It mandated the legislature to set more precise and ambitious reduction targets to ensure compliance with Germany’s commitments under the Paris Agreement.
Conclusion
In February 2025 the South Korean government, under former acting President Choi Sang-mok, announced its ambition to design a long-term plan to achieve carbon neutrality by 2050. This was in response to South Korean Constitutional Court’s July 2024 ruling which highlighted the pressing need for governments to adopt concrete and legally enforceable measures to address climate change, safeguarding both environmental integrity and the rights of future generations. Enabled by transnational advocacy networks, this case sets a significant precedent for climate litigation in a region acutely vulnerable to the impacts of extreme weather events and rising sea levels. Thereto, the judges creatively linked the constitutional principle of ‘statutory reservation’ to the international environmental law principle of intergenerational equity. This decision advances climate accountability and exemplifies the growing role of judicial systems in shaping global environmental governance.
A previous version of this contribution was presented at the second conference of the Swiss Network for Law and Society in Bern.