On December 2, 2024, public hearings began as part of deliberations seeking an advisory opinion from the International Court of Justice (ICJ) on States’ obligations regarding climate change and their legal responsibility when those obligations are breached. Over roughly two weeks, a record 96 countries and 11 regional organizations delivered statements. This is the first attempt to address States’ legal responsibility for climate change and marks a major step forward on an environmental issue that has drawn global attention.

Leading this effort is Vanuatu, a small island nation in the South Pacific. In Pacific Island countries including Vanuatu, greenhouse gas emissions, the cause of climate change, are minimal, yet the impacts are severe and threaten the survival of nations and their peoples. Vanuatu has long led Pacific countries in addressing climate change.

This article looks back at the current situation facing the Pacific Islands and the series of developments that led to the current proceedings at the ICJ.

(This event was also selected as No. 6 in “GNV’s Top 10 Hidden News Stories of 2024”.)

Hearing at the ICJ (Photo: UN Photo/ICJ-CIJ/Frank van Beek [Fair use])

 The state of climate change in the Pacific Islands

The Pacific Islands are scattered across the Pacific Ocean, numbering more than 4,000 islands in total. Indigenous peoples have migrated to and settled on these islands over many centuries. After experiencing colonial rule by European countries, the United States, Australia, and Japan from the 16th century onward, several countries gained independence following Samoa’s independence in 1962. However, many islands in the Pacific remain non-independent and under the control of European states and others. For details, see this GNV piece.

Looking at individual countries and territories, population and land area vary widely, from Papua New Guinea with about 10 million people (2025) to Niue with around 1,800 (2025) (Note 1). The economies of most countries and territories are fragile because their lands are dispersed over vast areas, domestic markets are small, they are geographically distant from international markets, and industries are hard to develop. As a result, there is a tendency to rely on aid and other support from other countries, especially former colonial powers. In exchange, some countries enter into free association and other arrangements and thus receive significant influence from other states beyond the economic sphere.

Warnings that climate change threatens the very existence of the Pacific Islands have been voiced for a long time. Multiple anomalous phenomena occurring in the ocean reflect the complexity and gravity of climate change. The three blows—accelerating sea-level rise, ocean warming, and acidification—are devastating for small-island territories.

According to UN reports, the average sea-level rise in the Pacific reached 15 cm between 1993 and 2023, and if global temperatures rise 1.5–3.0°C above pre-industrial levels, the Pacific could face a maximum sea-level rise of 50–68 cm in the future, with the potential impacts already observed in various places. For example, on Fiji’s Vanua Levu, some communities have been forced to relocate inland due to flooding linked to sea-level rise and coastal erosion.

Rising sea temperatures and acidification are altering ecosystems. For instance, studies confirm another global coral bleaching event since 2023. Coral bleaching has far-reaching implications—economic and for food security—especially for people living within coral ecosystems.

Damage from a cyclone in Vanuatu in 2015 (Photo: United Nations Development Programme / Flickr [CC BY-NC-ND 2.0])

In addition to the three blows above, the increase in extreme weather is also a major problem, with many countries and territories suffering serious damage from storm surges, flooding, and intense cyclones. In March 2023, Cyclones Judy and Kevin struck Vanuatu in succession, affecting 66% of the population and causing total damages estimated at USD 430 million.

While such climate crises are occurring across the globe and not only in the Pacific, it is clear that the level of harm in the Pacific has already reached a grave stage.

Climate action to date

To counter these threats, Pacific countries and territories have strengthened regional cooperation. The Pacific Islands Forum (PIF) is part of that effort. Climate change not only increases disaster risk but also profoundly affects politics and economic development. PIF serves as a venue for dialogue and regional cooperation across a broad range of fields—politics, economics, and security—and has achieved groundbreaking agreements in climate policy. One example is the “Framework for Resilient Development in the Pacific (FRDP) 2017–2030.” For more on PIF, see this GNV article.

However, the long-standing constraint of insufficient funding remains. Although there are international climate funds, structural barriers limit the Pacific’s access to adequate finance.

Coastal protection project in Tuvalu (Photo: UNDP Climate / Flickr [CC BY-NC 2.0])

Among the key international rules governing climate action between States is the Paris Agreement. Adopted at COP21 in 2015, the agreement was hailed as groundbreaking for establishing a framework that calls on all Parties, including low-income countries, to reduce greenhouse gas emissions. However, it remains mostly a regime of voluntary efforts and encouragement, with no obligations beyond reporting progress. While various climate measures are being implemented under the Paris Agreement, their results have been insufficient due to the lack of legal enforceability.

Here it is worth noting three key concepts in climate action: “mitigation,” “adaptation,” and “loss and damage.” “Mitigation” refers to measures that address the causes of climate change, such as reducing greenhouse gas emissions. “Adaptation” refers to measures taken against the unavoidable impacts of the climate crisis, such as building seawalls to prepare for flooding and sea-level rise. “Loss and damage” refers to measures addressing adverse impacts that occur despite mitigation and adaptation efforts. The concept of “loss and damage” is closely tied to equity and fairness, because many of the countries most vulnerable to climate change are those with the least emissions. The term was formally introduced at COP19 in 2013 and has since gained prominence. Pacific countries also place high importance on this concept, and at COP27 in 2022 they strongly advocated for prioritizing the establishment of a fund for loss and damage. As a result, COP27 created the first fund dedicated to “loss and damage.”

In November 2024, COP29 was held in Baku, Azerbaijan. Discussions were difficult and extended beyond the original schedule, but there was progress on climate finance. Parties agreed to a compromise target of USD 300 billion per year by 2035 for climate finance contributions. While this falls far short of the USD 1.3 trillion requested by low-income countries vulnerable to climate change, it is three times the current goal. Other outcomes included decisions on rules for international carbon credit trading, agreements related to energy, and discussions on gender and climate change, leaving some tangible results.

Nevertheless, many argued that concrete progress was still insufficient. The outcome further underscored the need to move beyond cooperation based on “goodwill” to obligations with legal force. Vanuatu also voiced its frustration, expressing deep concern over the lack of progress on key agenda items such as the new collective quantified goal (NCQG) on climate finance, the mitigation work programme (MWP), and the global goal on adaptation (GGA). It emphasized that COP has continued for many years and that business as usual is no longer acceptable. In reality, greenhouse gas emissions and the planet’s average temperature continue to set new records each year. Expectations for the ICJ proceedings have grown accordingly.

Discussions on small island developing States at COP29 (Photo: Commonwealth Secretariat / Flickr [CC BY-NC 2.0])

Growing calls

The current effort to bring these concerns to the ICJ and clarify States’ obligations and responsibilities for climate change began in an international environmental law classroom at the University of the South Pacific’s Vanuatu campus. In 2019, 27 law students in a “practical learning” course set a goal of creating jurisprudence applicable to countries of all sizes as the most progressive legal means to address climate change. The students did not confine themselves to classroom work: they drafted a memorial and sent it to PIF member states. They also approached Vanuatu’s foreign minister directly; impressed, the minister moved to take action at the government level. In 2022, under Vanuatu’s leadership, PIF officially decided to seek an advisory opinion from the ICJ.

Requesting an advisory opinion from the ICJ requires following certain procedures. Under Article 96 of the UN Charter, the ICJ accepts requests for advisory opinions only from the General Assembly and the Security Council, or from other organs and specialized agencies authorized by the General Assembly. PIF chose the path of a request by the UN General Assembly and began seeking support from UN Member States. To secure adoption in the General Assembly, a core group of 18 countries (Note 2) was formed to deliberate and draft the text. In March 2023, at the 77th UN General Assembly, the resolution was adopted by consensus, deciding to request the ICJ to opine on States’ obligations under international law regarding climate change.

At the hearings

The questions put to the ICJ are twofold: “What are the obligations of States under international law to ensure the protection of the climate system and other parts of the environment from anthropogenic emissions of greenhouse gases for States and for present and future generations?” and “What are the legal consequences under these obligations for States where, by their acts and omissions, they have caused significant harm to the climate system and other parts of the environment?” The second question in particular addresses the responsibility of high-income countries that have caused major environmental harm toward low-lying, low-income small island States and others.

Vanuatu’s statement at the ICJ (Photo: UN Photo/ICJ-CIJ/Frank van Beek [Fair use])

At the public hearings, which began on December 2, 2024, Vanuatu’s Minister of Lands and Natural Resources, Ralph Regenvanu, delivered the opening statement. Vanuatu argued that it is a victim of other nations’ actions and that it has the right to receive compensation for harms from major greenhouse gas–emitting countries contributing to climate change, contending that climate change undermines the right of peoples to self-determination in the UN Charter by transforming the environmental basis of political, economic, social, and cultural life. Many countries and organizations broadly concurred. One of the students who launched the movement at the University of the South Pacific also addressed the Court.

The Alliance of Small Island States (AOSIS), representing 39 small island and low-lying coastal developing countries including Grenada and the Cook Islands, also participated, arguing that international law must evolve to respond to climate change and its unequal impacts. Along with technical and restorative support, it called for affirmation of the principle of “continuity of statehood” for regions affected by climate change—so that States can maintain their existence even if their land territory is physically altered or entirely submerged by sea-level rise.

However, many major greenhouse gas emitters signaled a reluctance to accept new legal responsibilities. For example, Saudi Arabia, a major oil producer, argued that existing UN climate treaties already provide a complete answer on States’ obligations and opposed establishing further legal responsibilities. Germany, a member of the core group that drafted the General Assembly resolution, also said the Paris Agreement is the decisive treaty defining States’ obligations, prompting disappointment from other countries.

Joining the opposition to further legal responsibility were the United States, the United Kingdom, Australia, China, South Africa, and others. China, the world’s largest annual CO2 emitter, stated that greenhouse gas emissions do not constitute an internationally wrongful act under general international law. The United States, the second-largest emitter, acknowledged responsibility but remained reluctant to make existing treaties legally binding, saying the climate crisis can be solved only through international cooperation.

An Australian coal mine (Photo: Adani Mining Australia / Wikimedia Commons [CC BY-SA 4.0])

Hopes and disappointments

The move to bring this issue to the ICJ is likely to have broad social significance. First, the attempt to clarify the legal effect of obligations and responsibilities for environmental harm has been highly praised by many countries and NGOs as a groundbreaking step in international environmental law. The participation of more than 100 countries and organizations—the most in ICJ history—in delivering statements reflects the world’s high level of interest. Moreover, the fact that statements were heard not only from “vulnerable” countries but also from international bodies such as the European Union (EU) and the Organization of the Petroleum Exporting Countries (OPEC) is another reason this moment is considered unprecedented. It is also cited as a success of multilateral diplomacy by the so-called “Global South” of low-income countries.

The proceedings will take several months, and the ICJ’s final advisory opinion is expected sometime in 2025. An advisory opinion is not legally binding, but as a decision of a court with legal weight and authority, it is respected and contributes to the interpretation and development of international law. The advisory opinion on climate change could influence future global judicial processes, be cited in domestic courts, and shape diplomatic negotiations, with such potential effects noted. UN Secretary-General António Guterres stated it “could help drive bolder and stronger climate action.”

At the same time, these debates exposed clear fault lines. Christelle Pratt, representing the Organization of African, Caribbean and Pacific States (OACPS), expressed “huge disappointment” with major powers that argued against going beyond existing frameworks for climate action. She emphasized the need not only to craft new climate treaties but also to reconsider the entirety of international law.

To secure a safe future for people around the world, we now await the ICJ’s advisory opinion with anticipation.

Note 1: Although Niue participates as a state in regional bodies such as the Pacific Islands Forum, it is not a UN Member State.
Note 2: The 18 countries are Angola, Antigua and Barbuda, Bangladesh, Costa Rica, Germany, Liechtenstein, the Federated States of Micronesia, Morocco, Mozambique, New Zealand, Portugal, Romania, Samoa, Sierra Leone, Singapore, Uganda, and Viet Nam.

Writer: Kyoka Wada

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