By Changmin Choi, Director of Plan 1.5

Heatwaves, heavy rains, wildfires, droughts… As unprecedented climate disasters become a daily occurrence, South Korea is facing a crucial decision in responding to the climate crisis. Our country will soon decide how much greenhouse gases (GHGs) we will cumulatively emit by 2050, the target year for carbon neutrality. Following the Constitutional Court’s decision on the climate lawsuit last August, the National Assembly must legislate the national GHG reduction pathway for 2031-2049 (long-term reduction pathway) by February next year.

At this critical juncture, a historic event has occurred that timely shifts the direction of the global response to the climate crisis. The International Court of Justice (ICJ) issued an advisory opinion on the obligations of States in respect of climate change at the request of the UN General Assembly (UNGA).

The ICJ stated that the discretion of States in determining their nationally determined contributions (NDCs) is limited by international law. If a country fails to do its utmost to ensure its NDC represents the highest possible ambition, it may be committing an internationally wrongful act. A country that commits an internationally wrongful act may be held legally responsible to provide restitution or compensation to countries affected by the climate crisis. So, how is the discretion of States in determining their NDCs limited?

The ICJ determined that the goal of limiting global warming to 1.5°C, as decided by the Conference of the Parties (COP) to the UNFCCC, is a “scientifically based consensus target.” The NDCs, determined by each country, must collectively achieve the 1.5°C goal. According to the first Global Stocktake (GST) conducted in 2023, the world must reduce net GHG emissions by 60% by 2035 compared to 2019 to achieve the 1.5°C goal. The ICJ stated that the NDC of each country must consider the GST results.

The reduction of 60% by 2035 compared to 2019 (equivalent to a 61% reduction based on South Korea’s NDC base year of 2018) is the global average. The ICJ emphasized that the most important principle of the climate change treaty framework is the principle of common but differentiated responsibilities and respective capabilities (CBDR/RC). According to this principle, countries with greater responsibility for GHG emissions and stronger capabilities to respond to the climate crisis must contribute more to global GHG reduction efforts.

What is the level of responsibility and capability of South Korea? As of 2022, our country ranked fifth in annual emissions, fifth in per capita emissions, eighth in emissions per gross domestic product (GDP), and eighth in cumulative emissions since 1990 among Organisation for Economic Co-operation and Development (OECD) countries, indicating a significant responsibility for GHG emissions. In terms of climate crisis response capabilities, our country is consistently ranked at the highest level in major indicators of development level presented by the Intergovernmental Panel on Climate Change (IPCC), such as the UN Statistics Division’s classification of developed/developing countries, the World Bank’s income level classification, and the UN Development Programme’s (UNDP) Human Development Index (HDI).

The policy implications of the ICJ Advisory Opinion are clear. South Korea, with significant responsibility and strong capabilities, must contribute at least more than the global average to global GHG reduction efforts towards achieving the 1.5°C goal. In other words, our country’s 2035 NDC should aim to reduce emissions by more than 61% compared to 2018 net emissions.

The National Human Rights Commission of Korea (NHRC) also recommended in June that the Ministry of Environment and the Carbon Neutrality Committee establish a 2035 NDC that must consider the GST results and fully reflect the CBDR/RC principle. The NHRC further emphasized that the reduction pathway should be set to “reduce as much greenhouse gas as possible from the beginning,” considering the carbon budget to prevent excessive burdens on future generations. “Carbon budget” refers to the total amount of carbon dioxide (CO2) that can be emitted to limit global warming to 1.5°C.

Plan 1.5, a climate advocacy and research organization to which the author belongs, calculated the maximum carbon budget for our country to be 8.74 billion tons (as of 2020) based on scientific facts and international standards, and proposed a 2035 NDC of a 65% reduction compared to 2018 net emissions. This is slightly higher than the global average reduction rate of 61%, and is considered a fair contribution to achieving the 1.5°C goal in light of the CBDR/RC principle.

The Constitutional Court of Korea, in its climate lawsuit decision, specified three conditions that the national GHG reduction target must meet to protect the basic rights of the people. First, it must fairly contribute to global reduction efforts. Second, it must not pass excessive burdens to the future. And third, it must be based on scientific facts and international standards. Currently, several amendments to the Carbon Neutrality Framework Act, which stipulates the long-term reduction pathway, have been proposed in the National Assembly, transcending party lines. All of these amendments include provisions for calculating South Korea’s carbon budget and stipulate the minimum level of the 2035 NDC to be 60-65%. It is encouraging to see that discussions have begun to pave the way for legislative improvements that align with the direction of the Constitutional Court’s decision and the ICJ Advisory Opinion.

However, the government announced plans to determine and submit the 2035 NDC to the UN by November this year, earlier than the February 2026 deadline for the National Assembly to legislate the long-term reduction pathway. On 8 September, the government presented draft targets for the 2035 NDC at the National Assembly for upcoming public consultation. The draft targets include not only the reduction rate aligned with the national carbon budget (65%) and the global average reduction rate necessary to achieve the 1.5°C target (61%), but also the reduction rate based on the linear reduction pathway used for the current 2030 NDC decision (53%), as well as even lower reduction rates (mid to high 40%).

The linear reduction pathway is an arbitrary method that derives reduction targets by connecting the emission levels of the NDC base year, 2018, and the carbon neutrality target year, 2050, with a straight line. This method is not based on scientific facts or international standards. The current 2030 NDC of South Korea, determined using this method, has been criticized by international evaluation agencies, receiving the lowest rating and being assessed as leading to a warming level of 3-4°C. Now that the ICJ has confirmed that the discretion of a country in determining its NDC is limited to the extent that it can achieve the 1.5°C target, it is highly inappropriate, if not illegal, that targets excessively exceeding the discretionary scope be included in the 2035 NDC draft targets.

The government and the National Assembly must determine the long-term reduction pathway, with the 2035 NDC being a crucial part of it, at a level that can achieve the 1.5°C goal in accordance with the Constitutional Court’s decision and the ICJ Advisory Opinion. Otherwise, they will not only fail to fulfill the constitutional duty to protect the citizens and future generations from the climate crisis but also commit an internationally wrongful act by neglecting the climate crisis, which the ICJ defined as an “existential problem of planetary proportions.”

* * *

This Guest Article is part of a project that seeks to raise awareness and build momentum and knowledge around the ICJ advisory opinion on obligations of States in respect of climate change and to promote a better understanding of the implications of the advisory opinion among sustainable development decision makers.