Key Highlights
- The International Court of Justice (ICJ) issued an advisory opinion affirming state obligations under the Paris Agreement are binding commitments.
- Dr. David R. Boyd, former UN Special Rapporteur on human rights and the environment, discusses how this ruling can shape climate negotiations at COP30.
- The right to a clean, healthy, and sustainable environment is recognized by 165 states in their domestic laws but not yet enshrined in the Universal Declaration of Human Rights.
- Despite the US’s withdrawal from the Paris Agreement, there are state-level efforts in countries like Canada towards recognizing this environmental right domestically.
The ICJ Advisory Opinion on Climate Change: A Game-Changer for International Law
In a significant ruling issued late July 2025, the International Court of Justice (ICJ) has provided unprecedented clarity to international law by affirming that state obligations under the Paris Agreement—including the 1.5°C target—are binding commitments. This decision is part of a broader corpus of international law that also includes human rights law and customary international law.
Dr. David R.
Boyd, former UN Special Rapporteur on human rights and the environment, has spoken extensively about how this advisory opinion stands to shift negotiating dynamics in global climate talks. His insights were gathered by JURIST ahead of COP30 (the 30th Conference of the Parties), which concluded in Brazil that month.
Shifting Negotiating Dynamics
In an interview, Boyd highlighted one aspect he particularly appreciated: the court’s rejection of the “lex specialis” argument. This argument posited that obligations related to climate change are contained within specific climate treaties like the United Nations Framework Convention on Climate Change (UNFCCC), the Paris Agreement, and the Kyoto Protocol. Instead, the ICJ ruled that these climate change treaties are part of a broader framework of international law.
Boyd emphasized that this ruling offers clarity after 33 years of contested interpretation since the Rio Earth Summit in 1992. “The International Court of Justice has affirmed that state obligations under climate change are not limited to those flowing from the treaties,” Boyd explained, adding that some of the world’s largest and most powerful states (such as the United States, Russia, and Germany) have argued before the ICJ that such a right did not exist in international law.
The Right to a Clean, Healthy, and Sustainable Environment
Boyd also elaborated on the broader implications of this advisory opinion. He noted that the right to a clean, healthy, and sustainable environment is recognized by 165 states through their domestic laws or regional treaties. This right encompasses both procedural elements (access to information, public participation, and access to justice) and substantive elements (such as securing safe air, water, food, and a non-toxic environment).
Despite the US withdrawing from the Paris Agreement again, Boyd remains optimistic about state-level efforts in countries like Canada. “We see states like Vermont considering constitutional amendments to include this right,” he said. New York had already enshrined the right in its state constitution in 2022, and such actions demonstrate a growing recognition of the importance of environmental rights at the domestic level.
Adding the Right to the Universal Declaration of Human Rights
In another interview from 2024, Boyd expressed optimism about potentially adding this right to the Universal Declaration of Human Rights. With the ICJ’s affirmation, he believes there is increased momentum for such an addition. “From conversations with several governments, they have been supportive,” Boyd noted.
Implications for COP30 and Beyond
The advisory opinion has fundamentally changed negotiating dynamics at COP30, according to Boyd. Small island states and other climate-vulnerable nations now come to the conference with high expectations. “We will see a bloc of states that respect the opinion of the court and seek to enforce it through political negotiations,” he stated.
However, wealthy countries like those mentioned earlier may challenge how to interpret the advisory opinion, leading to a clash between politics and law at COP30. Boyd added that while an enforcement mechanism might not be immediately drawn up, the ruling has laid the groundwork for climate change litigation if states fail to meet their obligations.
On the domestic front, Boyd pointed out that Canada’s amendment of its Canadian Environmental Protection Act (CEPA) to recognize the right to a clean, healthy, and sustainable environment is a step forward.
However, he noted limitations: “The right is only recognized at the federal level and within the bounds of CEPA.” He also mentioned ongoing climate change lawsuits in Canada that argue for the implicit recognition of this right under section 7 of the Charter.
Boyd concluded cautiously optimistic about global progress on climate change. “Solar and wind energy are now the most affordable sources of energy, and electric vehicle adoption is growing rapidly,” he noted, highlighting potential solutions to inspire hope despite current challenges.
The advisory opinion from the ICJ has indeed reshaped how states approach their obligations under the Paris Agreement, making it a crucial development in international environmental law. As negotiations continue at COP30, the impact of this ruling will be closely watched by all involved parties.
