The 2023 International Training Program on Climate and Environmental Change along the Belt and Road started in Xi’an on Sep. 12. Photo: Sun Zifa/CNSphoto

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Climate change is a pressing issue that requires collective action from all nations. The international community is placing greater expectations on the role of international law in addressing this global challenge. 

Influence 

Climate change has been largely left out of current international legal systems and their guiding principles, primarily because it was not yet a matter of great concern to individual countries, human development and even existence during the formation of these systems. Today, however, climate change is responsible for significant changes in the underlying factors in the formulation and implementation of international law. 

On the one hand, climate change affects almost all current international legal systems. For instance, global warming leads to rising sea levels and displacement of baselines of territorial sea, altering the scope of internal waters, territorial seas, exclusive economic zones, and continental shelves, as well as the status of maritime features. This not only affects the sovereignty of coastal states, but may also trigger disputes between coastal and non-coastal states over territorial sovereignty and maritime rights. 

In some coastal states, rising sea levels result in the submersion or complete loss of land territory, which affects the application of customary international law regarding the recognition of statehood. Rising sea levels are also contributing to the emergence of climate migrants or refugees, presenting a significant challenge to existing international migration and refugee laws. 

On the other hand, climate change has prompted the reconsideration of the guiding principles of international law. National interests have long been viewed as the fundamental driving force behind state actions, and state consent as the fundamental basis for the practice of international law. State-centrism and statist individualism therefore constitute the basic guiding principles of international law, profoundly influencing the formulation and implementation of specific international legal systems. 

The aforementioned principles, to some extent, align with reality and serve the purpose of safeguarding national sovereignty and maintaining international peace. However, they severely limit the capability of international law to address issues that go beyond specific national interests. Since the mid-20th century, the concept of an international community has been increasingly valued, giving rise to practices of substantive and procedural law that go beyond specific national interests and state consent. 

Climate change concerns the interests of all countries and cannot be addressed by any country alone. This may push countries to engage in climate cooperation by overcoming the obstacles of national interests and power politics, while also reshaping the spirit of state-centrism and statist individualism in international law. 

Response 

International law can and should play an active role in tackling climate change, as the problem has become increasingly dire, and state behavior is increasingly regulated by international law. To this end, two fundamental issues need to be addressed at the normative level. One involves making adjustments to current international law, and the other involves developing specific international law on climate change. 

Many current international legal systems were established before climate change became a major global concern. They rarely include provisions for addressing climate change and may, on the contrary, act as legal barriers to such efforts. It should be noted that several international treaties have incorporated climate change clauses in recent years, allowing contracting parties to take measures accordingly. 

Since the 1990s, significant progress has been made in international lawmaking on climate change, primarily through the UNFCCC, the Kyoto Protocol, and the Paris Agreement. These special treaties not only stipulate the international obligations of the contracting parties, but also offer guidelines on additional measures against climate change. Nevertheless, the meaning of many international legal norms concerning climate change remains unclear, which hinders the ability of international law to address climate change as expected. 

In recent years, several trends have been observed in the practice of international law on climate change.

First, international legal systems concerning climate change are increasingly becoming hard law. International law is no longer limited to expressing concerns, establishing principles, and urging action. Instead, it is defining clear and enforceable rights and obligations. 

Second, the principle of common but differentiated responsibilities (CBDR) has been challenged. The Kyoto Protocol imposes greenhouse gas emission obligations only on developed countries based on the CBDR principle, whereas the Paris Agreement imposes such obligations on all countries. While this reflects the nature of climate change as a major international concern, its legitimacy is open to debate. 

Third, the implementation mechanisms of international law on climate change continue to be improved. A number of countries are pushing for the judicialization process of international law on climate change in order to clarify the rights and obligations of state actors and promote the fulfilment of obligations and the exercise of rights. 

Fourth, capacity-building is receiving increasing attention. A set of recent international treaties have specifically incorporated capacity-building issues. This indicates the international community has realized that rights and obligations at the normative level alone are insufficient to tackle climate change, and issues of state capacity must be addressed at the practical level. 

Lastly, the practice of international law on climate change also entails risks, such as intensifying tensions between different international legal systems and improper expansion of power by international organizations. For instance, the EU’s Carbon Border Adjustment Mechanism entered into application in its transitional phase on October 1st, 2023, and the permanent system is expected to enter into force in 2026. The possibility that this mechanism constitutes a new form of trade protectionism and undermines the multilateral trading mechanism has raised widespread concern. 

Cai Congyan is a professor at Fudan University Law School. 

Edited by WANG YOURAN