Before the clenching constipation of reluctant and cloddish policy makers, climate change advocates have found courts surprisingly amenable to their concerns. Bodies of environmental law in national courts and international tribunals are now burgeoning on the obligations of states to address ecological harms and the effects of greenhouse gas emissions. As is often the case, it’s the children at the vanguard, pointing scolding fingers at the adults in filing petitions and drawing attention to the dangers of tardiness.
2025 is proving to be something of a good year for climate change litigants and activists. On July 3, 2025, the Inter-American Court of Human Rights, as requested by Chile and Colombia, issued an advisory opinion addressing the scope and extent of obligations with respect to respecting, protecting and fulfilling substantive rights regarding the climate emergency; procedural rights relevant to the same; and clarifying obligations towards vulnerable groups (children, environment activists, women, indigenous groups and so forth).
The advisory note is more onerous in not merely insisting that States observe a negative obligation – that is, to not violate rights directly – but that they also take positive steps through “reinforced due diligence” to deal with foreseeable harms arising from climate change. This entailed identifying a right to a safe climate. The prohibition against causing irreversible damage to the climate and the environment was also deemed a jus cogens norm, compellable under international customary law similarly to the prohibition against genocide, slavery and torture. Striking a novel note, the IACtHR also noted that Nature and its components should be acknowledged as subjects of rights, a move in what has been described as “ecological constitutionalism” in the Latin American context.
On July 23, the International Court of Justice also handed down an advisory opinion that promises to be momentous in its aggravations and irritations – at least to certain lawmakers and industries. For those countries still reaping the material, gluttonous rewards of fossil fuel exploration, production and consumption, this is bound to be of some concern. Begun daringly in 2019 as an action by a group of Pacific Island students from the University of the South Pacific, with able support from Vanuatu, the court unanimously found that producing and consuming fossil fuels “may constitute an internationally wrongful act attributable to that state”.
Vanuatu’s submission to the Court emphasised the grim consequences of not adequately addressing state obligations to address greenhouse gas emissions, including the shocks of internal displacement. “The forced displacement from ancestral lands and ecosystems leads to grave cultural losses. It impairs territorial sovereignty and inhibits the affected peoples from making a free choice about their futures.”
The decision is important in several respects. It opines that countries have a legal obligation to mitigate climate change and limit the rise in global temperature to 1.5°C above pre-industrial levels, a goal outlined in the Paris Agreement. States are accordingly obligated to advance climate plans that reflect their “highest possible ambition” in making “adequate contribution” in limiting temperature rises to that level. The discretion of countries to arrive at elastic “nationally determined contributions” was limited by the requirements of “due diligence”. Any such determined contributions had to be compliant with the obligations under the Paris Agreement and international environmental law.
The Court also reached the view that responsibility for breaches of climate change treaties “and in relation to the loss and damage associated with the adverse effects of climate change, is to be determined by applying the well-established rules on State responsibility under customary international law.”
Direction is also given on what a State wrong in not mitigating climate change might look like. A failure to take the appropriate steps to protect the climate system from greenhouse gas emissions, “including through fossil fuel production, fossil fuel consumptions, the granting of fossil fuel exploration licenses or the provision of fossil fuel subsidies” could be “an internationally wrongful act which is attributable to that State.” The wrong arises, not from the emissions as such, but from the failure to protect “the climate change system from significant harm resulting from anthropogenic emissions of such gases.”
The decision is crucial in considering historical responsibility and the thorny issue of reparations, the nature and quantum of the latter being dependent “on the circumstances”. Both nation states and “injured individuals” could seek reparations from historically heavy emitters, a point previously dealt with most unsatisfactorily via “loss and damage” finance discussions through UN climate negotiations. The impediment that such finance be only provided voluntarily is potentially overcome by the legal obligation to repair harm. This is particularly important for countries with economies at risk to climate change disruption (tourism, fishing, agriculture) and the enormous costs arising from dealing with environmental disasters.
The ICJ proved dismissive of arguments – often made by states with powerful fossil fuel lobbies – that attributing precise responsibility in the context of climate change was impossible. The Court observed “that while climate change is caused by cumulative GHG emissions, it is scientifically possible to determine each State’s total contribution to global emissions, taking into account both historical and current emissions.”
Vanuatu’s climate change minister, Ralph Regenvanum, is already filling his file with teasing blackmail for appropriate targets. Given its location in the Pacific, and prominence as a fossil fuel exporter, Australia is in his sights. “Australia,” he told Australia’s Radio National, “is committing internationally wrongful acts as it is sponsoring and subsidising fossil fuel production and excessive emissions.” Canberra needed “to align itself with the advisory opinion and cease this conduct that is contributing to emissions and start making reparations.”
From being a slow field of speculative pursuit and vague pronouncements, climate change litigation has become a branch of international customary law. Current developments in this field even include a petition to the African Court of Human and Peoples’ Rights from May 2025 seeking to do something along the lines pursued by the ICJ and the IACtHR, with a focus on African states. This development will be unwelcome among the fossil fuel lobby groups that still threaten and bribe political representatives – and it’s been a long time coming.
The post Adjusting the Temperature: Climate Change and International Law first appeared on Dissident Voice.
This content originally appeared on Dissident Voice and was authored by Binoy Kampmark.