Recognising the ‘urgent’ threat facing the world, the ICJ – in a unique unanimous statement by 15 judges – concluded that those suffering from human-caused climate change may be entitled to reparations. The ICJ opinion rests largely on the application of existing law, explains Carbon Brief, clarifying that ‘climate harms’ can clearly be linked to major emitters and fossil-fuel producers.

This important case was triggered by a group of Pacific island students, championed by the government of Vanuatu, and gained unprecedented levels of input from nations round the world.

In a unanimous decision, the ICJ judges concluded that the production and consumption of fossil fuels ‘may constitute an internationally wrongful act attributable to that state’. Moreover, the opinion statement says that limiting global warming to 1.5°C should be considered the ‘primary temperature goal’ for nations, and that nations are obliged to make ‘adequate contributions’ – that is, make reparations.

Although the ICJ opinion is not considered to be ‘binding’ for governments, it could have significant influence as vulnerable groups and nations push for stronger climate action or seek compensation in court.

How it started
The case was initiated by 27 students from the University of the South Pacific in Fiji in 2019, who established the Pacific Island Students Fighting Climate Change. Joining forces with other youth organisations round the world, they lobbied state representatives to take action, which in turn led the government of Vanuatu to engage with the Pacific island community to build a community of like-minded vulnerable countries.

Following this initiative, Vanuatu engaged in discussions across Europe, Asia, Africa and Latin America to encourage other countries to join the effort. After three rounds of consultations, the resolution was put before the UN General Assembly with the backing of 105 sponsor countries. And on 29 March 2023, the Assembly unanimously adopted the resolution formally requesting an ‘advisory opinion’ from the ICJ.

Two big questions
The resolution posed two questions to the Court, addressing a range of laws and principles, including the UN climate regime and the Universal Declaration of Human Rights.

First: What are the ‘legal obligations’ of states under international law to ensure the protection of the climate system and other parts of the environment from anthropogenic emissions of greenhouse gases for states and future generations?

Second: What are the ‘legal consequences’ under these obligations for states where they, by their ‘acts and omissions’, have caused significant harm to the climate system and other parts of the environment, in particular, with respect to small island developing states… and peoples and individuals of present and future generations affected by climate change.

After a two-year process, the judges have defined the scope and meaning of the questions put to the UN General Assembly. Among the laws identified are three UN climate change treaties: the UNFCC, the Kyoto Protocol and the Paris Agreement. Other treaties are also considered, covering biodiversity, ozone depletion, desertification and the oceans, as well as principles relating to the prevention of significant harm to the environment.

The international Court says it received an unprecedented response, with 91 written statements and 107 oral statements – the highest level of participation in the Court’s history. That demonstrated broad agreement among nations that climate change is a major threat and that emissions should be cut in accord with the Paris Agreement.

Mixed response
However, there were major divergences on the breadth and nature of obligations under international law to limit global warming, as well as on the consequences of any breaches.

‘Emerging economies’ such as China and Saudi Arabia, along with historical high emitters such as the UK and EU, argued that climate obligations under international law should be defined solely by reference to the UN climate regime. While ‘vulnerable nations’ said that wider international law should also apply, with potential for legal consequences, including demand for reparations.

This is seen as a departure from UN climate talks, where the main areas of dispute tend to be between ‘developed’ and ‘developing’ countries, with the latter encompassing both high- and low-emitting nations, explains Carbon Brief.

The ICJ judges also organised a meeting with scientists representing the Intergovernmental Panel on Climate Change (IPCC), including Sir Jim Skea, IPCC Chair (and former President of the Energy Institute), and eight other climate scientists, to enhance the Court’s understanding of the scientific findings regarding the impact of climate change.

The advisory opinion states: ‘It is scientifically established that the climate system has undergone widespread and rapid changes,’ and adds that ‘the consequences of climate change are severe and far-reaching’. Moreover, ‘the IPCC notes that adaptation measures are still insufficient’.

The Court flatly rejected the argument put forward by high emitters, such as the US, UK and China, that current treaties are the end of the matter. These nations have argued that the climate treaties form a ‘lexis specialis’ – a specific area of law that precludes the application of broader general international law principles. On the contrary, the ICJ says countries have legal obligations under general international law, including ‘a duty to prevent significant harm to the environment’, with further obligations arising under human rights law and other treaties.

What the ICJ opinion means for the energy transition
‘The Court has essentially sided with the Global South and small island developing states,’ Professor Jorge Viñuales, Harold Samuel Professor of Law and Environmental Policy at the University of Cambridge, told Carbon Brief. Moreover: ‘The Court says that countries’ obligations extend not only to GHG emissions, but also to fossil-fuel production and subsidies. This is important because major producers are not necessarily major emitters and vice versa.’

The Court sets out ‘appropriate measures’ for states to demonstrate ‘due diligence’ to prevent significant harm to the environment, beyond climate treaties, including ‘regulatory mechanisms designed to achieve rapid and sustained reductions in emissions’.

Given that US President Donald Trump signed an Executive Order on election last November to pull out of the Paris Agreement for a second time, there is a question how the ICJ’s opinion might apply to the US, despite its major contribution to climate change.

The ICJ also suggests that states have obligations under human rights law.

Although the Court says that countries can, in principle, face liability for climate harms – opening the door to potential reparations for ‘loss and damage’ – Professor Viñuales told Carbon Brief: ‘Perhaps the main take-away from the opinion is that the Court recognised the principle of liability for climate harm, as actionable under the existing rules. However, climate justice is governed by the general international law of “state responsibility”, which provides solutions for the recurrent arguments levelled to escape liability for climate harm.’

Essentially, the ICJ rejects the notion that it is too difficult to hold countries accountable for climate change. ‘Breached obligations’ include failure to set out or implement nationally determined contributions (NDCs) under the Paris Agreement, or to sufficiently regulate emissions of GHG, according to the ruling. Nevertheless, the ICJ stresses that it is not responsible for pointing fingers at particular countries, only for issuing a ‘general legal framework’ that countries can follow.

Some countries argue that GHG emissions are not like other environmental damage, such as localised chemical pollution. Others suggest that it is ‘perfectly possible’ to attribute such damage to states that, for example, have laws to promote fossil-fuel production and consumption.

Reactions to the ruling
UK barrister at Doughty Street Chambers, Harj Narulla, told Carbon Brief: ‘The ICJ’s ruling has provided a legal pathway for developing states to seek climate reparations from developed states… States can bring claims for compensation or restitution for all climate-related damage, including for loss and damage.’

A spokesperson for the European Commission, Anna-Kaisa Itkonen, says the opinion ‘confirms the magnitude of the challenge we face and the importance of climate action’.

In response to the opinion, a spokesperson for the White House told Reuters: ‘As always, President Trump and the entire administration is committed to putting America first and prioritising the interests of everyday Americans.’

António Guterres, Secretary-General of the UN, said the ICJ had issued a ‘historic’ opinion and added: ‘They made it clear that all states are obligated under international law to protect the global climate system. This is a victory for our planet, for climate justice and for the power of young people to make a difference.’

The UK newspaper The Daily Telegraph expressed concern that the UN ‘has opened the door to Britain being sued over its historic contribution to climate change’, and added that the opposition Conservative and Reform parties both rejected the ruling.

Greenpeace, Earthjustice and other environmentalists hailed the opinion as ‘a landmark moment for climate justice and accountability’.

Fossil fuels under pressure
A section of the ruling is focused on the fossil fuel sector. It says: ‘Failure of State to take appropriate action to protect the climate from GHG emissions – including through fossil fuel production, fossil fuel consumption, the granting of fossil fuel exploration licences or the provision of fossil fuel subsidies – may constitute an internationally wrongful act which is attributable to that State.’

As it went to press, New Energy World was unable to source any comments from major fossil-fuel producers in response to the ICJ advisory opinion.

But the fossil majors are not off the hook. Joy Rayes, a Policy Officer at the Grantham Research Institute of the London School of Economics, told Carbon Brief: ‘Litigants can cite the advisory opinion in future litigation, which includes the language around fossil fuels. While not legally binding, the advisory opinion carries moral weight and authority, [and] can influence domestic decision-making around new fossil fuel projects. If states and corporations fail to transition away from fossil fuels, their risk for liability increases.’