Climate Change Ruling From International Court Puts US on Notice

It’s not every day that a court issues a ruling applying to every country in the world. Yet, that is what happened on July 23, when the International Court of Justice released its advisory opinion outlining nations’ legal obligations relating to climate change.

During an era of decreasing US multilateralism, it’s natural to wonder how this international law determination matters for the US. The short answer is that, yes, the ruling implicates the US but in arguably less intuitive ways than would have been the case before the Trump administration enacted its nationalistic policy agenda.

There are three key takeaways from the decision for the US.

First, climate obligations under international law are broad, extending beyond the Paris Agreement, which the US withdrew from in January. Because the agreement articulates duties to combat climate change more specifically than any other treaty, one might assume the US withdrawal constitutes an exemption from international legal obligations related to climate change.

The International Court of Justice advisory opinion delivers a gentle reminder to remember what they say about assuming.

In addition to clarifying legal obligations for countries that are still part of the Paris Agreement, the decision spells out requirements under other treaties and declarations. For example, the US retains duties to act on climate change as a party to both the broad United Nations Framework Convention on Climate Change, of which the Paris Agreement is a part, and the International Convention on Civil and Political Rights.

Legal obligations to combat climate change further extend into the realm of customary international law. Such duties require countries to act with due diligence in collectively protecting the environment and preventing environmental degradation independent of any treaty-based responsibilities. This means that the US can’t discharge its accountability under customary international law by withdrawing from any (or even all) treaties.

Second, climate obligations under international law are deep, requiring substantial action. According to the International Court of Justice, token lip service isn’t enough when it comes to climate change action.

For example, the Paris Agreement creates numerous legally binding obligations, including a general duty for developed countries to monetarily assist developing countries in their efforts to address climate change.

The court’s advisory opinion clarifies that this requirement “must be interpreted in light of other provisions in the agreement, including the collective temperature goal” to limit global warming to 1.5-2°C above pre-industrial levels. By all accounts, achieving this target would require massive financial mobilization.

Of course, the US isn’t directly subject to this particular provision following its withdrawal from the Paris Agreement. Yet, the expansive nature of the ruling implicates the US in other ways.

The court makes it clear that abiding by treaty-based obligations under the Paris Agreement is an indicator of compliance with the separate customary international law duty to act with due diligence in addressing climate change. This is true even for countries that aren’t party to the Paris Agreement.

Ultimately, countries carry the burden of demonstrating they have acted with the requisite due diligence, and failing to abide by treaty requirements—even for non-parties—can serve as evidence to the contrary.

Third, the consequences of noncompliance with climate obligations under international law are still being determined. The International Court of Justice explicitly notes that determinations of state compliance with legal obligations related to climate change are context-dependent and must be evaluated on a case-by-case basis. In other words, the advisory opinion is a launching pad for more particularized disputes.

For many years, international courts and tribunals have already begun building out the scaffolding of liability under this area of international law, particularly at the intersection of climate change and human rights.

Cases such as Daniel Billy v. Australia and Klimaseniorinnen v. Switzerland—as well as advisory opinions from the Inter-American Court of Human Rights and the International Tribunal on the Law of the Sea—have helped clarify what it takes for countries to comply with obligations to address climate change under international law. The court’s advisory opinion specifies parameters within which such litigation can continue and expand.

Admittedly, this accountability mechanism is limited in the context of the US. For example, the US can’t be held directly responsible for treaty obligations under the International Convention on Civil and Political Rights in US courts. In the absence of a global enforcement authority presiding over sovereign nations, countries acting within the international law system rely heavily on naming and shaming to shift governmental behavior, particularly when it comes to customary international law and human rights. The Trump administration has routinely disregarded such reputational compliance mechanisms when acting on the global stage.

Yet, other geopolitical processes are operating simultaneously. As the US increasingly withdraws from international cooperation, other countries likely will move in to fill the resulting power vacuum. Nations that demonstrate sincere efforts to abide by their climate obligations under international law could wrestle significant soft power away from the US within the global community.

If the US continues to diminish its role in the liberal world order, thumbing its nose at international law obligations to combat climate change, already-shifting political alliances among nations are poised to accelerate their realignment. The International Court of Justice advisory opinion puts this trend into sharp relief.

This article does not necessarily reflect the opinion of Bloomberg Industry Group, Inc., the publisher of Bloomberg Law, Bloomberg Tax, and Bloomberg Government, or its owners.

Author Information

Paul Rink is an associate professor at Seton Hall Law School whose research focuses on climate change, strategic litigation, international environmental law, and environmental justice.

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