sujithxavier TWAILR: Reflections

Environmental Adjudication in the Anthropocene: Legal Imagination and the Management of Unequal Harm

Asker Ibne Firoz, 'River is dying' (2023) wikimedia commons

Gustavo Leite Neves da Luz reflects critically on a series of advisory opinions across different international courts and tribunals over recent years on the burning question of state responsibilities to address climate change and environmental harm.

TWAILR: Reflections ~ 93/2026

The climate crisis is not caused by an undifferentiated humanity. The benefits and harm of fossil-fuelled industrialisation were never evenly distributed. International law did not create that history on its own. It nevertheless organised authority over territory and resources, shielded extractive transactions, and externalised environmental costs from development until they became objects of regulation or compensation. International law is in the midst of an unusual advisory cycle. In a span of two years, three international courts and tribunals have clarified State duties in relation to climate change: the 2024 Advisory Opinion of the International Tribunal for the Law of the Sea (ITLOS); the 2025 Advisory Opinion of the Inter-American Court of Human Rights (IACtHR); and the 2025 Advisory Opinion of the International Court of Justice (ICJ).1 This concentration of cases reflects a crisis that is already altering the conditions of human and non-human life.2

In this context, the ‘Anthropocene’ can be understood as a legal and political description of a condition in which human activity transforms planetary systems, without taking a position on formal geological nomenclature. The resulting harms arise from countless acts, span borders and generations, interact with ecological processes, and may become irreversible before a single causal chain can be established. The Intergovernmental Panel on Climate Change has emphasised that vulnerability is intensified by underlying inequality, marginalisation, and historical and ongoing patterns of colonialism.3

This Reflection argues that the advisory cycle strengthens environmental obligations while translating planetary crisis within a familiar legal grammar. Prevention and due diligence remain central, alongside cooperation, environmental impact assessment, participation, and reparation. The frame renders ecological disruption as an administrable risk, assesses compliance through reasonableness and procedure, and organises responsibility around breach, causation, and remedy. It can discipline conduct. Its limits emerge from what it selects for legal attention and what it treats as contextual, particularly the distribution of authority and economic power through which risk was produced. The question is whose harm becomes cognisable, whose knowledge defines it, and whether cumulative or irreversible loss can be addressed without confronting the sources of unequal exposure.

The Managerial Frame and What It Leaves Out

International environmental adjudication has gradually assembled a preventive vocabulary built around due diligence, notification, cooperation, environmental impact assessment, and responsibility. From the Corfu Channel Case through to the Pulp Mills Case, from the Sponsoring States Advisory Opinion to the South China Sea Arbitration,4 courts and tribunals have used this vocabulary to identify risk, review State conduct, and require preventive measures.5 This vocabulary renders ecological conflict legally reviewable through questions of conduct, procedural compliance, reasonable regulation, and attributable harm. This move is not merely reductive: these doctrines can constrain discretion, clarify obligations, and prevent damage.

Climate change exposes the limits of what this vocabulary can capture. The harm is cumulative, produced by many actors across time and borders, and potentially irreversible before a single causal chain can be proved. It is embedded in histories of extraction, colonial administration, unequal development, and fossil-fuelled industrialisation. The existing doctrine can ask whether a State acted reasonably, whether a breach occurred, and whether an injury was caused. However, it fails to examine who benefited from the underlying development model, why some communities were deemed more exposed, who controls authoritative knowledge, and how losses beyond restoration should be allocated.

Once disputes are organised through this vocabulary, then conduct, breach, causation, and remedy move to the foreground. The legal and economic arrangements that produced vulnerability remain contextual facts rather than independent objects of responsibility.

Recognition of Indigenous, local, and traditional knowledge challenges the monopoly of expert evidence. Institutional gatekeeping nevertheless remains: courts and other institutions determine whose knowledge is admitted, who may speak for affected communities or Nature, and which injuries cross legal thresholds.

The Advisory Cycle and its Legal Grammar

Among the three opinions, ITLOS made the most concrete classificatory contribution. It held that anthropogenic greenhouse gas emissions fall within ‘pollution of the marine environment’ under article 1(1)(4) of the United Nations Convention on the Law of the Sea (UNCLOS). That finding brought greenhouse gas emissions within Part XII of UNCLOS. States are now subject to a general duty to protect and preserve the marine environment, an obligation to prevent, reduce, and control marine pollution, and rules governing pollution from or through the atmosphere.6

This classification had practical consequences. ITLOS rejected the view that climate change was too general or too atmospheric to fall within the law of the sea. It connected due diligence with best available science, precaution, cooperation, technical assistance, and the regulation of public and private conduct. However, classifying it as marine pollution directs the focus towards State measures against pollution. Historical benefit, unequal exposure, and irreversible loss are addressed mainly through capabilities, cooperation, and assistance, rather than being treated as distinct bases for allocating responsibility. ITLOS therefore strengthens control over conduct without making the political economy of carbon-intensive development the juridical question.7

The ICJ widened the field of applicable law. It treated climate change as having no simple territorial limit and refused to confine the analysis to climate treaties. Instead, the opinion drew on customary prevention and cooperation, UNCLOS, human rights law, and the law of State responsibility. It described due diligence as potentially stringent and responsive to risk, capabilities, historical and current contributions, development, and national circumstances. Environmental impact assessment forms part of the procedural dimension created for prevention.

The ICJ’s approach to prevention and due diligence also has more immediate regulatory consequences. A failure to take appropriate action may constitute an internationally wrongful act. Relevant obligations, especially customary prevention, are erga omnes. Breach, attribution, causation, and injury must nevertheless be established in the circumstances of a particular claim. Historical contributions may shape the standard of conduct; the opinion does not convert them into a formula for allocating responsibility or reparation. The cumulative character of climate change therefore remains in tension with the claim-specific structure of responsibility.8

The sharpest departure from the inherited form came from the IACtHR. The 2025 Advisory Opinion of the IACtHR articulates enhanced due diligence, recognises a right to a healthy climate, treats Nature as capable of autonomous legal protection, and characterises the prohibition of irreversible climate and environmental damage as jus cogens. It also ties climate decision-making to information, participation, access to justice, and local, traditional, and Indigenous knowledge. Several of these propositions were adopted by divided votes, which affects their authority and reception.

The underlying reasoning is relational: climate appears as a condition of the ecological systems within which humans, other species, and future generations exist. Recognition of Indigenous, local, and traditional knowledge challenges the monopoly of expert evidence. Institutional gatekeeping nevertheless remains: courts and other institutions determine whose knowledge is admitted, who may speak for affected communities or Nature, and which injuries cross legal thresholds. AO-32/25 enlarges the field of legally cognisable climate harm. Access to that field nevertheless remains institutionally controlled.9

The production of environmental law can therefore reproduce the inequalities it seeks to address. Advisory opinions can shift this terrain by giving small States and affected communities authoritative language for litigation, diplomacy, and domestic mobilisation.

Judicial Hope and its Geography

The advisory cycle did not emerge only from the institutional centre. Small island States drove the ITLOS request, which asked the Tribunal to clarify States Parties’ obligations under UNCLOS to prevent, reduce, and control marine pollution from anthropogenic greenhouse-gas emissions and to protect and preserve the marine environment from climate-change impacts. The ICJ process followed mobilisation led by Vanuatu and Pacific Island Students Fighting Climate Change and was authorised by UN General Assembly Resolution 77/276. Chile and Colombia requested the Inter-American opinion, which drew 263 briefs from 613 participants. The requests came from regions where sea-level rise, extreme events, food insecurity, displacement, and territorial loss are lived realities rather than abstractions. They ask institutions historically shaped by more powerful States to clarify obligations arising from activities whose benefits accumulated elsewhere.10

A TWAIL perspective brings the distribution of authority into view. Inequality concerns both exposure to harm and the power to define the problem. High-emitting States and institutions with greater scientific, financial, and diplomatic capacity can have greater influence on negotiating texts, evidentiary standards, emissions accounting, and regulatory pace. States and communities with fewer resources must translate lived loss through inventories, models, expert reports, and causal narratives before it becomes legally cognisable. The production of environmental law can therefore reproduce the inequalities it seeks to address.

Advisory opinions can shift this terrain by giving small States and affected communities authoritative language for litigation, diplomacy, and domestic mobilisation. They make it harder to dismiss climate obligations as merely political or aspirational. Their effects, however, depend on resources that an opinion cannot itself supply: finance, technology, monitoring capacity, and access to decision-making. Nor do the opinions revise the legal arrangements that allocated control over resources and externalised ecological costs.

When read together, the opinions mark a significant victory for those who insisted that climate change is not external to the law. They also reveal the terms on which the crisis becomes juridically intelligible, chiefly through pollution, risk, due diligence, participation, and reparation. These categories can discipline inaction. They developed, however, within a legal order that made territory and nature available for extraction, separated benefit from ecological cost, and located responsibility after harm became attributable. The remaining question is whether their use can expose those enabling conditions rather than confining legal response to the management of consequences.

The argument extends beyond courts because adjudication draws from and feeds back into institutional practices that determine what counts as environmental harm, admissible evidence, and an adequate response. The Agreement on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ) and the Area — the seabed and ocean floor and their subsoil beyond the limits of national jurisdiction — provide two tests of the same managerial logic: each allocates authority through procedures that depend heavily on expertise, information, and institutional capacity. The BBNJ Agreement, in force since 17 January 2026, establishes mechanisms for environmental impact assessment, area-based management tools, capacity-building, and the transfer of marine technology. The distributive effect of these mechanisms depends on who can produce and contest the knowledge on which those mechanisms rely. Access to baseline data, research vessels, modelling capacity, expert time, and institutional agendas remains unequal. Reporting and review may widen participation. They may also recast unequal capacity as a neutral difference in evidentiary credibility.11

The tension is sharper in the Area. UNCLOS defines its resources as the common heritage of mankind, and entrusts the International Seabed Authority (ISA) with organising and controlling mineral-related activities for the benefit of humankind. No commercial exploitation has been approved, and the exploitation regulations remain under negotiation. With no State able to claim sovereignty over the Area or its resources, authority is exercised through sponsorship, contractual arrangements, and institutional compliance. In this limited functional sense, institutional procedure performs part of the legitimating work that property titling performs within a national jurisdiction: ISA certifies an activity as collectively authorised without creating sovereignty. The unresolved issue is whether that certification redistributes control over knowledge, capital, benefits, and exposure to risk, or merely gives existing concentrations an institutional form.12

What Legal Imagination Requires

The imaginative limits of international law refer to the boundaries set by what its doctrines and institutions recognise as legally relevant. Historical extraction is treated as background rather than a source of present responsibility; Nature appears primarily as an object of regulation; and affected peoples are approached more often as beneficiaries or consultees than as co-authors of standards. Cumulative and irreversible loss is often recast as a problem of proof. Courts and tribunals matter because they can stabilise obligations and provide authoritative language, but adjudication is only one site within a wider political and legal struggle. TWAIL scholarship has long shown how the law may protect nature while preserving the categories through which it is governed as territory, resource, and external object.13

Existing scholarship does not yield a single alternative model but indicates elements of a different approach, beginning with the production of knowledge. When access to research infrastructure, monitoring technology, and funding is so unequal, scientific evidence cannot be treated as disembodied expert data. Indigenous knowledge should carry weight grounded in rights to participation, culture, self-determination, and control over knowledge. Local and community knowledge is legally distinct from Indigenous knowledge and should therefore be treated as more than supplementary information.

Irreversibility, cumulative harm, and ecological thresholds present a further issue. These conditions should inform the design of obligations and remedies, rather than appearing only as evidentiary difficulties. Material conditions must also enter the legal architecture more explicitly: capacity-building and technology transfer as conditions of equal participation; reparation where breach, injury, and causal nexus are established; and adequate funding for the UN climate regime’s loss-and-damage arrangements. These arrangements address harms that restoration or bilateral responsibility cannot address.14

Inter-State reparation and climate loss-and-damage funding answer different questions and should not be confused. Under the law of State responsibility, reparation concerns the injury caused by an internationally wrongful act and depends on an established causal nexus; where the wrongful act is continuing, cessation may also be required.15 Loss-and-damage arrangements, by contrast, concern cooperative support for climate-related harm without themselves determining State responsibility or compensation. The two may operate alongside one another, but their legal bases and distributive functions remain distinct.

The advisory opinions mobilise established obligations against climate inaction and supply language that affected States and communities can use. The limitation of the advisory opinions is that they address ecological collapse through categories inherited from the legal order that accompanied carbon-intensive development. The existing law nevertheless remains indispensable.

Legal analysis must look beyond additional procedures, reports, and institutional coordination. It should examine how authority was distributed in producing risk, identify the actors who benefited and the communities exposed, and ask who can define lawful repair. This requires moving from speaking for affected peoples towards recognising their authority to shape the terms of legality.

The Anthropocene changes which doctrines must confront it. The relevant history is institutionalised: it is the history through which extraction, unequal exposure, and environmental sacrifice were organised. Legal imagination reaches its limit where the law manages the consequences of that history while leaving its organising structures beyond the reach of responsibility and transformation.

  1. ITLOS, Request submitted by COSIS, Advisory Opinion, 21 May 2024, Case No. 31; IACtHR, Climate Emergency and Human Rights, Advisory Opinion AO-32/25, 29 May 2025; ICJ, Obligations of States in respect of Climate Change, Advisory Opinion, 23 July 2025, General List No. 187. The wider adjudicatory context includes Verein KlimaSeniorinnen Schweiz and Others v Switzerland, Judgment, 9 April 2024, ECtHR Application No. 53600/20.
  2. The World Meteorological Organization found that 2024 was the warmest year in the 175-year observational record, at 1.55 °C above the 1850–1900 average, while ocean heat, sea-level rise, and acidification continued to increase. World Meteorological Organization, State of the Global Climate 2024 (2025), key messages and sections on global temperature, ocean heat, sea level, and ocean acidification.
  3. IPCC, Climate Change 2022: Impacts, Adaptation and Vulnerability, Summary for Policymakers, B.2.
  4. Corfu Channel, Merits, Judgment, ICJ Reports 1949, 4, at 22; Pulp Mills on the River Uruguay, Judgment, ICJ Reports 2010, 14, paras 101, 197 and 204–205; Sponsoring States Advisory Opinion, ITLOS Reports 2011, 10, paras 110–120 and 131–135; South China Sea Arbitration, Award, 12 July 2016, RIAA vol XXXIII, 153, paras 940–993.
  5. Martti Koskenniemi, ‘The Fate of Public International Law: Between Technique and Politics’ (2007) 70:1 Modern Law Review 1, at 9–30.
  6. UNCLOS Arts. 1(1)(4), 192, 194, 197, 202–203, 206 and 212; ITLOS Advisory Opinion, paras 159–179, 197–243 and 264–277.
  7. ITLOS Advisory Opinion, paras 205–213, 235–243, 293–312, 323–339 and 344–367; Sponsoring States Advisory Opinion, paras 110–120 and 131–135.
  8. ICJ Advisory Opinion, paras 93–100, 113–173, 272–300, 425–443 and 449–455, especially paras 290–298, 427, 438 and 440.
  9. IACtHR Advisory Opinion AO-32/25, paras 219–237, 269–320, 358–363 and 471–560; operative paras 3, 7–10 and 14. Enhanced due diligence was adopted unanimously; Nature as a subject of rights and the jus cogens proposition were adopted by four votes to three; the right to a healthy climate by five votes to two.
  10. UNGA Res. 77/276, 29 March 2023; IACtHR Advisory Opinion AO-32/25, para 8.
  11. BBNJ Agreement, Arts. 7, 17–26, 27–39 and 40–46; United Nations Treaty Collection, entry into force 17 January 2026.
  12. UNCLOS Arts. 136–137, 140, 145, 153 and 157; 1994 Part XI Agreement; Sponsoring States Advisory Opinion, paras 74–81, 110–120 and 145–150; ISA, Draft Exploitation Regulations, ISBA/31/C/CRP.1/Rev.3, and outstanding issues, ISBA/31/C/CRP.7 (2026); Karin Mickelson, ‘Common Heritage of Mankind as a Limit to Exploitation of the Global Commons’ (2019) 30:2 European Journal of International Law 635–663.
  13. Usha Natarajan & Kishan Khoday, ‘Locating Nature: Making and Unmaking International Law’ (2014) 27:3 Leiden Journal of International Law 573–593; Usha Natarajan & Julia Dehm, ‘Where is the Environment? Locating Nature in International Law’ (2019) TWAILR: Reflections 3; Carmen G. Gonzalez, ‘Environmental Justice, Human Rights, and the Global South’ (2015) 13 Santa Clara Journal of International Law 151.
  14. UNDRIP Arts. 3–4, 18–19, 29 and 31–32; Escazú Agreement Arts. 5–8; Certain Activities, Compensation, Judgment, ICJ Reports 2018, 15, paras 34 and 41–43; ICJ Advisory Opinion, paras 433–438 and 449–455; Paris Agreement Art. 8; Decisions 2/CP.27, 2/CMA.4, 1/CP.28 and 5/CMA.5.
  15. ILC, Articles on Responsibility of States for Internationally Wrongful Acts, Arts. 30–31.