Introduction
Climate change stands as perhaps the most profound and complex challenge confronting the international legal order in the 21st century. Its pervasive impacts, ranging from sea-level rise to extreme weather events, necessitate a rigorous examination of how states can be held accountable for their contributions to this global crisis. Traditional principles of international state responsibility, largely codified in the International Law Commission’s (ILC) Articles on Responsibility of States for Internationally Wrongful Acts (ARSIWA), face significant conceptual and practical hurdles when applied to the unique characteristics of climate change. This article explores the evolving landscape of state responsibility for climate change under international law, analyzing the applicability of established norms, the challenges of attribution and causation, and the emerging jurisprudential trends shaping the discourse.
Foundations of State Responsibility and Climate Change
The ARSIWA, reflecting customary international law, establishes that an internationally wrongful act of a state entails its international responsibility if the act (or omission) is attributable to the state and constitutes a breach of an international obligation of that state (ARSIWA, Article 2). Applying these foundational principles to climate change, however, presents formidable difficulties.
First, **attribution** is problematic. Greenhouse gas (GHG) emissions, the primary drivers of climate change, originate from countless sources worldwide, both state-owned and private. While a state is responsible for acts of its organs and persons acting under its direction or control (ARSIWA, Articles 4-8), linking specific emissions from one state to a particular climate change impact in another state, or even within its own territory, is immensely challenging due to the cumulative and global nature of atmospheric pollution. The global commons aspect means that the atmosphere is a shared resource, and the harm is diffuse rather than originating from a single, identifiable source in a direct transboundary manner.
Second, establishing a **breach of an international obligation** requires identifying specific legal duties related to climate change. The primary instruments in international climate law, the United Nations Framework Convention on Climate Change (UNFCCC) and its Paris Agreement, largely adopt a facilitative and consensual approach, focusing on nationally determined contributions (NDCs) rather than imposing strict, legally binding emission reduction targets on individual states that could easily trigger responsibility for breach. While the Paris Agreement obliges parties to “communicate” and “maintain” NDCs and pursue domestic mitigation measures “with the aim of achieving the objectives of such contributions” (Paris Agreement, Article 4), the legal precision required for a breach claim remains elusive.
Despite these challenges, certain existing principles of international environmental law offer potential avenues. The **”no-harm rule,”** a cornerstone of customary international law established in cases like the *Trail Smelter* arbitration (United States v. Canada, 1941) and reaffirmed in Principle 21 of the Stockholm Declaration (1972) and Principle 2 of the Rio Declaration (1992), posits that states have the sovereign right to exploit their own resources pursuant to their own environmental policies, but also the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of other states or areas beyond the limits of national jurisdiction. While its application to transboundary atmospheric pollution has been widely accepted, demonstrating a direct causal link between a specific state’s GHG emissions and specific harm in another state, particularly in the context of diffuse climate change, is an onerous evidentiary burden.
Furthermore, the principle of **due diligence**, exemplified in the *Corfu Channel* case (United Kingdom v. Albania, ICJ 1949), mandates states to prevent their territory from being used for acts contrary to the rights of other states. This could translate into an obligation for states to take all necessary measures to prevent significant transboundary harm from their GHG emissions, even if the precise causal link to specific damage is complex.
Emerging Jurisprudence and Future Directions
The current jurisprudential landscape indicates a growing willingness among international tribunals and domestic courts to grapple with state responsibility for climate change. This shift is particularly evident in the increasing requests for advisory opinions and domestic litigation.
Most notably, the International Tribunal for the Law of the Sea (ITLOS) delivered an advisory opinion in May 2024, clarifying the specific obligations of states parties to the UN Convention on the Law of the Sea (UNCLOS) regarding climate change in the marine environment. The ITLOS opinion affirmed that states have “specific obligations” under UNCLOS to “take all necessary measures to prevent, reduce and control pollution of the marine environment from anthropogenic greenhouse gas emissions” and to protect and preserve the marine environment from climate change impacts. While an advisory opinion is not legally binding in the same way as a contentious judgment, it provides significant authoritative guidance on the interpretation of existing international law and is likely to influence future state practice and legal developments.
Similarly, the UN General Assembly has requested an advisory opinion from the International Court of Justice (ICJ) on the obligations of states in respect of climate change, encompassing issues of state responsibility, human rights, and intergenerational equity. The ICJ’s forthcoming opinion is expected to further delineate the scope of states’ obligations and the legal consequences of their actions and omissions concerning climate change. These international judicial pronouncements demonstrate a clear trend towards clarifying and potentially strengthening the legal framework for climate accountability.
Domestically, decisions such as *Urgenda Foundation v. Netherlands* (Dutch Supreme Court, 2019) and *Neubauer v. Germany* (German Constitutional Court, 2021) have established that states have a positive obligation, often rooted in human rights, to take robust action against climate change. While these are national judgments, their reasoning and outcomes resonate with international law principles and exert pressure on states to meet their international climate commitments.
Conclusion
The application of international law principles of state responsibility to climate change is in a state of dynamic evolution. While the traditional framework of ARSIWA faces inherent challenges concerning attribution, causation, and the specificity of international obligations, the “no-harm rule” and the principle of due diligence provide a foundational basis for accountability. The recent advisory opinions from ITLOS, and the anticipated one from the ICJ, represent crucial steps in clarifying and operationalizing states’ obligations under existing international legal instruments. These developments, alongside domestic climate litigation, underscore an increasing expectation for states to undertake concrete and effective measures to mitigate climate change and adapt to its impacts. The future trajectory of international law on climate change will likely witness a continued push towards more explicit legal duties, stronger accountability mechanisms, and a reinterpretation of sovereignty in light of shared planetary vulnerabilities, moving beyond aspirational declarations towards enforceable responsibilities.
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About the Author:
Burak Şahin is an attorney registered with the Manisa Bar Association. He earned his LL.B. from Kocaeli University and is pursuing an M.A. in Cinema at Marmara University. With expertise in International Law, he delivers interdisciplinary legal analysis connecting law, technology, and culture. Contact: mail@buraksahin.av.tr
