A global maritime court found on Tuesday that greenhouse gases constitute marine pollution, a major breakthrough for small island states threatened by the rise in sea levels caused by global warming.
In its first climate-related judgment, the International Tribunal for the Law of the Sea (ITLOS) said emissions from fossil fuels and other planet-warming gases that are absorbed by the oceans count as marine pollution.
Its ruling – an “advisory opinion” that should nevertheless provide a precedent for cases elsewhere – also said countries must go beyond the requirements of the landmark 2015 Paris Agreement to protect the marine environment and the states that depend on it.
“What happened today was that the law and science met together in this tribunal, and both won,” said Cheryl Bazard, Ambassador to the European Union of the Bahamas, one of nine Caribbean and Pacific island nations that sought the opinion.
Small island nations with scant economic power but acutely vulnerable to climate change have long felt neglected by successive global summits where pledges to cut carbon emissions have fallen far short of the minimum for limiting the worst effects of global warming.
The court said states have a legal obligation to monitor and reduce the emissions that contribute to climate change and laid out specific requirements for their environmental impact assessments.
It also said states’ targets for cutting greenhouse emissions must be set objectively based on the best available science and relevant international rules and standards, thus setting the bar higher than the Paris Agreement did.
“The ITLOS opinion will inform our future legal and diplomatic work in putting an end to inaction that has brought us to the brink of an irreversible disaster,” said Antigua and Barbuda Prime Minister Gaston Browne.
Nikki Reisch, director at the Centre for International Environmental Law, said: “To those that would hide behind the weaknesses of international climate treaties, this opinion makes clear that compliance with the Paris Agreement alone is not enough.”
Joie Chowdhury, a senior attorney at the Centre for International Environmental Law, said: “It’s the first time an international court has unequivocally affirmed that states do not have unfettered discretion, but specific obligations under international law to act urgently, ambitiously and equitably, to protect oceans from the drivers and impacts of climate change.”
The tribunal also says that wealthier nations must shoulder a bigger portion of the burden and support developing states with funding and technical assistance.
Payam Akhavan, a professor of international law at the University of Toronto and a legal adviser to Cosis, said he hoped that states meeting at the Cop29 climate conference in November and subsequent international climate talks would “revisit the assumptions that they have had about whether their conduct is sufficient to meet their international obligations”.
Climate activists and lawyers said the decision could influence two opinions on states’ climate obligations that are pending from the Inter-American Court on Human Rights and the International Court of Justice.
A similar potential precedent was laid down last month, when the European Court of Human Rights agreed with plaintiffs who argued that Switzerland was violating their human rights by not doing enough to combat climate warming.
Eselealofa Apinelu, representing the South Pacific island of Tuvalu, said Tuesday’s opinion made clear that all states were legally bound to protect the marine environment, and other states, from the existential threats of climate change.
“It is an important first step in holding the major polluters accountable for the sake of all humankind.”
But the road to concerted global action is far from smooth.
China, the world’s biggest carbon polluter, had argued in court that the Tribunal did not have general authority to issue advisory opinions, saying these could fragment international law. China’s foreign ministry was not immediately available for comment.
The other nations in the group that brought the case were Palau, Niue, Vanuatu, St Lucia, St. Vincent and Grenadines and St Kitts and Nevis.
Gaston Browne, the prime minister of Antigua and Barbuda, said he hoped the three parallel opinions would create a “harmonious message” that it was time for action.
He added: “We stand at a pivotal moment in history.”
The ruling will shape future climate cases.
The International Tribunal for the Law of the Sea delivered its Advisory Opinion on the request submitted to the Tribunal by the Commission of Small Island States on Climate Change and International Law.
The Advisory Opinion was read by Judge Albert Hoffmann, who presided over the case.
The request had been submitted to the Tribunal by the Commission of Small Island States on Climate Change and International Law (“the Commission”) on 12 December 2022. The Commission requested the Tribunal to give an advisory opinion on the following questions:
What are the specific obligations of State Parties to the United Nations Convention on the Law of the Sea (`UNCLOS’), including under Part XII:
(a) to prevent, reduce and control pollution of the marine environment in relation to the deleterious effects that result or are likely to result from climate change, including through ocean warming and sea level rise, and ocean acidification, which are caused by anthropogenic greenhouse gas emissions into the atmosphere?
(b) to protect and preserve the marine environment in relation to climate change impacts, including ocean warming and sea level rise, and ocean acidification?
In its Advisory Opinion, the Tribunal decides unanimously that it has jurisdiction to give the advisory opinion requested by the Commission and unanimously decides to respond to the request by the Commission.
The replies to the questions submitted by the Commission, as contained in the operative clauses of the Advisory Opinion, are reproduced below:
The Tribunal unanimously
Replies to Question (a) as follows:
(a) Anthropogenic GHG emissions into the atmosphere constitute pollution of the marine environment within the meaning of article 1, paragraph 1, subparagraph 4, of the Convention.
(b) Under article 194, paragraph 1, of the Convention, States Parties to the Convention have the specific obligations to take all necessary measures to prevent, reduce and control marine pollution from anthropogenic GHG emissions and to endeavour to harmonize their policies in this connection. Such measures should be determined objectively, taking into account, inter alia, the best available science and relevant international rules and standards contained in climate change treaties such as the UNFCCC and the Paris Agreement, in particular the global temperature goal of limiting the temperature increase to 1.5°C above pre-industrial levels and the timeline for emission pathways to achieve that goal. The scope and content of necessary measures may vary in accordance with the means available to States Parties and their capabilities. The necessary measures include, in particular, those to reduce GHG emissions.
(c) The obligation under article 194, paragraph 1, of the Convention to take all necessary measures to prevent, reduce and control marine pollution from anthropogenic GHG emissions is one of due diligence. The standard of due diligence is stringent, given the high risks of serious and irreversible harm to the marine environment from such emissions. However, the implementation of the obligation of due diligence may vary according to States’ capabilities and available resources.
(d) Under article 194, paragraph 2, of the Convention, States Parties have the specific obligation to take all measures necessary to ensure that anthropogenic GHG emissions under their jurisdiction or control do not cause damage by pollution to other States and their environment, and that pollution from such emissions under their jurisdiction or control does not spread beyond the areas where they exercise sovereign rights. This obligation applies to a transboundary setting and is a particular obligation in addition to the obligation under article 194, paragraph 1. It is also an obligation of due diligence. The standard of due diligence under article 194, paragraph 2, can be even more stringent than that under article 194, paragraph 1, because of the nature of transboundary pollution.
(e) Under articles 61 and 119 of the Convention, States Parties have the specific obligations to take measures necessary to conserve the living marine resources threatened by climate change impacts and ocean acidification. In taking such measures, States Parties shall take into account, inter alia, the best available science and relevant environmental and economic factors. This obligation requires the application of the precautionary approach and an ecosystem approach.
(f) The obligation to seek to agree under article 63, paragraph 1, and the obligation to cooperate under article 64, paragraph 1, of the Convention, require States Parties, inter alia, to consult with one another in good faith with a view to adopting effective measures necessary to coordinate and ensure the conservation and development of shared stocks. The necessary measures on which consultations are required must take into account the impacts of climate change and ocean acidification on living marine resources. Under article 118 of the Convention, States Parties have the specific obligation to cooperate in taking measures necessary for the conservation of living marine resources in the high seas that are threatened by climate change impacts and ocean acidification.
(g) Under article 196 of the Convention, States Parties have the specific obligation to take appropriate measures to prevent, reduce and control pollution from the introduction of non-indigenous species due to the effects of climate change and ocean acidification which may cause significant and harmful changes to the marine environment. This obligation requires the application of the precautionary approach.
Judges Jesus, Pawlak, Kulyk, Kittichaisaree and Infante Caffi append declarations to the Advisory opinion.
