🍻 Selber Bier Brauen

Im Kalten Krieg kam das Horrorszenario eines «nuklearen Winters» auf. Heute, 80 Jahre nach der Erfindung der Bombe, streiten Wissenschafter noch immer, wie stark ein Atomkrieg die Temperatur auf der Erde senken würde.

Eine ganze Reihe von Massnahmen trägt dazu bei, Beschwerden bei Arthrose zu lindern.

Sie seien tolle Hausgenossen, findet unser Autor. Und er freut sich über wissenschaftliche Studien, die nahelegen: Wer Hund oder Katze hat, bleibt kognitiv länger fit.

Kürzlich wurden die ersten Bilder des neuen Grossteleskops in Chile veröffentlicht. Wer war die Frau, die postum zur Namensgeberin wurde?

Alpen sind Orte der Extreme. Das zeigte sich im Wallis, als plötzlich der Gletscher ins Lötschental donnerte. Doch es gibt Messgeräte, die den Berg lesen können.

Lately, it has become en vogue all across Europe to ponder, worry about, or declare the imminent death of international law, a trend that has only grown stronger since first Israel and then the United States attacked Iran in June. On occasion, the tone of the professional commentariat has verged on mocking and even spiteful, especially when coming from the (neo-)realist corner of the political sciences. Esteemed political theorist Herfried Münkler, for instance, postulated the complete irrelevance of legal questions in the current geopolitical constellation. Carlo Masala, in a widely read essay for weekly Die Zeit, derided anyone who insists on compliance with established rules on the use of force as behaving like an unruly, immature adolescent unfit for the cold world out there and doing nothing more than “instrumentalising” the vocabulary of international law. If this sounds like a somewhat ghoulish argument recovered from the ruins of Fallujah, that’s because it is. Against this background, I scrutinise the German discourse surrounding Israel’s actions and its implications for the international legal order, with a focus on recent public statements by two of the state’s highest representatives.

That the debate has taken on particular salience in Germany partly comes down to the fact that, as Helmut Aust and Heike Krieger noted on this website, the Overton window of permissible discursive positions in that country seems to have shifted dramatically in the recent past. Since the publication of their op-ed in February, statements emerging from Berlin’s government circles have only become more troubling, above all in response to Israel’s and the U.S.’s use of armed force against Iran in June and in the context of the ICC arrest warrant for Israeli Prime Minister Benjamin Netanyahu. There is a certain irony in the fact that in less than two months’ time, the German capital, of all places – Aust’s and Krieger’s Freie Universität – will host the annual conference of the European Society of International Law, one of the premier gatherings of the discipline, devoted to the theme “Reconstructing International Law” after “a rough period of turbulence” for the last decade. It is, as Ntina Tzouvala put it aptly, not only a world but a discipline in crisis.

Violations of the law and normative stability

The crisis isn’t entirely the discipline’s own fault, however. The problem with erudite musings such as Münkler’s or Masala’s is not the implication that, in light of contemporary geopolitical realities, international law is not and cannot be fully operationally closed toward the system of global politics, to borrow Niklas Luhmann’s terminology. The problem is that irrespective of whether other, non-legal considerations – questions of strategy, politics, or “legitimacy” – are in play when a state decides to act, breaches of the law still need to be called out as such, or else the rule will erode. As observed by Thomas M. Franck in the aftermath of the 2003 Iraq War, “if the community of states fails to register its displeasure with the law’s violation in some significant fashion, it would be arguable that the norm is being allowed to lapse into meaninglessness”.¹⁾

Accordingly, it’s not the breach itself that threatens normative stability, it’s how the international community responds.²⁾ This could be witnessed after Russia’s full-scale invasion of Ukraine in February 2022, which was met with a broad and overwhelming reaction at the United Nations to the blatant act of aggression.³⁾ The main organs of the German state were likewise unambiguous. President Frank-Walter Steinmeier publicly chided Moscow for its “brutal” violation of international law, warning that war crimes may not remain unpunished because “international law is not a blunt sword that you can simply ignore”. Chancellor Friedrich Merz, then still in his function as whip of the Christian Democrats in the Bundestag, co-authored a parliamentary motion that condemned “Russia’s brutal aggression against Ukraine in the strongest terms”. Given these rightfully emphatic statements, it is even more glaring how miserably these same politicians failed when asked to uphold the prohibition of the use of force after Israel and the United States sent their bombers to Iran in June.

Israel’s justifications and the international response, then and now

Although not explicitly invoking a right to self-defence pursuant to Article 51 UN Charter, Israel, in its letter to the UN Security Council from 17 June, did offer a justification for its armed attack on Iran, citing “the last window of opportunity to prevent Iran from acquiring nuclear weapons” and “Iran’s ongoing aggression” to have made it inevitable to act “to defend its security and very existence”. Israel’s approach thus differed significantly from 2007, when its fighter jets destroyed the Al Kibar nuclear reactor in Syria without acknowledging the operation at all. Although such covert action is highly problematic from a legal perspective, given that the refusal to offer a legal justification carves out a sphere of lawlessness that risks undermining content and relevance of the prohibition of the use of force,⁴⁾ in turn it leaves either interpretation or development of the rule unaffected.⁵⁾ Unacknowledged violent conduct, as reprehensible as it is, is certainly less corrosive than an unlawful use of force out in the open that nonetheless goes unanswered. And despite Israel’s rationalisation, its attacks against Iran were just that (as was, by extension, the subsequent bombardment by the U.S.): unlawful uses of force. Not only did the state rely on an untenably expansive interpretation of the right to self-defence, it also presented no evidence “not easily open to misinterpretation or fabrication”, as Louis Henkin put it,⁶⁾ to support its claims.

For this reason, an unambiguous and public response to the unlawful use of force against Iran was called for. What such a process ideally looks like was demonstrated in June 1981 after an Israeli airstrike had taken out the Osirak nuclear reactor in Iraq. In its letter to the UN Security Council, Israel sought to justify its operation with arguments uncannily reminiscent of today, citing reliable intelligence that Iraq was seeking the development of nuclear weapons that it would use against Israel, which is why it “decided to act without further delay to ensure our people’s existence”. Yet on 19 June, the Security Council unanimously passed a resolution that “strongly condemn[ed] the military attack by Israel in clear violation of the Charter of the United Nations and the norms of international conduct”. During the debate preceding the vote, the representative of the United States, while emphasising the close bond between her (Republican) government and the state of Israel, and acknowledging the threat of Iraqi nuclear proliferation, insisted that “diplomatic means available to Israel had not been exhausted and the Israeli action has damaged the regional confidence that is essential for the peace process to go forward”.

Germany’s abject failure to uphold international law

Nothing of this sort, of course, happened this time. Among the numerous Western voices who bungled the matter (back home, NATO Secretary General and Trump sycophant-in-chief Mark Rutte did not fare any better), Germany’s President Steinmeier and Chancellor Merz gave particularly disturbing statements in two separate media interviews in late June. Merz – having caused much indignation as well as earned plaudits during the G7 Leaders’ Summit in Canada in mid-June when he praised Israel for having done the “dirty work” for the rest of us – explicitly refused to walk back his off-the-cuff remarks in an interview with Süddeutsche Zeitung on 27 June. Asked in a follow-up question whether this implies that, according to him, Israel simply had to violate international law, the chancellor – after confirming that Germany is “of course” bound by international law and suggesting that it was not for him to legally assess the attacks against Iran – countered with a list of questions that regurgitated a string of soundly refuted doctrinal constructions previously made in various academic fora, including a reference to the “existential” yet entirely ambiguous and in no way imminent threat of an attack from a nuclear bomb in the hands of Tehran.

Not to be outdone, Steinmeier, in an interview with public broadcaster Deutschlandfunk two days later, began by pontificating that “especially us Germans should declare the international legal order a part of our own identity, which means that we may not ignore when international law is not only disregarded but also derided”. (These remarks were in reference to the question of Netanyahu potentially visiting Berlin despite his outstanding ICC arrest warrant; lack of space prevents me from addressing that particular issue, which, with slightly different particulars, the president and chancellor handled just as terribly). If only he had left it at these empty platitudes. Honouring the Social Democratic tradition of abandoning principle when it would really count, however, the president continued by pointing to scholarly disagreements “in the papers” as to the lawfulness of Israel’s actions before likewise endorsing the flawed doctrine of pre-emptive self-defence, a legal position he had previously thoroughly rejected as Germany’s foreign minister in the context of the 2003 invasion of Iraq.

It is quite a trite insight that international law is bound to exhibit an immanent indeterminacy that is always vulnerable to being invoked to justify just about any behaviour absent centralised and consistent enforcement mechanisms – or a “guardian”, in Münkler’s terms. That is hardly an excuse for a head of state to evade clear positioning by pointing to divergent opinions in scholarship. More importantly, it doesn’t follow that legal arguments don’t matter in international political discourse; by delimiting what becomes accepted among the community of states, the law does exert stabilising and, yes, constraining effects. Moreover, a look across the Atlantic at the Trump administration’s recent actions toward the U.S. judiciary should suffice to demonstrate that the effectiveness of any law, at any time, ultimately hinges on political buy-in. Law is not some transcendental entity that exists independent of the people who are expected to apply, interpret, and follow it. This is why the hapless public statements by Merz and Steinmeier will prove so disastrous.

The price of Berlin’s hypocrisy

If the project of international law falters, it won’t be because it was thrown into a world where raw power reigns supreme, as the realists would have it. It will be because the people who were in a position to actualise it started wavering the moment consistency and sincere conviction became politically inconvenient, amid Germany’s rabid and delusional current media environment and due to their frankly inexcusable fealty to Netanyahu and his genocidal policies (which reached a new low on 21 July, when Germany refused to join a call by 28 states for an immediate ceasefire in Gaza). Paying mere lip service to the importance of international law and Berlin’s ostensibly steadfast commitment to it, as offered by Steinmeier and Merz, is devoid of any consequence. The attempts by the highest and the third-highest representatives of the Federal Republic to limit or undo the damage caused by previous statements were clumsy, unprincipled, and insufficient. As laid out in perfect detail by Marko Milanovic, Adil Haque, and Mary Ellen O’Connell, the armed attacks carried out by Israel and the United States against Iran were plainly illegal. Their allies should have said so clearly and publicly, just like the UN Security Council unanimously did in 1981, even if they happened to otherwise think that the attacks were strategically opportune or politically legitimate. That is the difference between international diplomacy and an academic debate. By refusing to condemn the attacks, Germany’s two leading politicians have failed in their constitutionally mandated obligation to uphold international law.

Bad arguments reverberate. Debates at the United Nations after Russia’s full-scale invasion of Ukraine in 2022 already palpably suffered from the echoes of the legally untenable rationalisations based on factually fraudulent premises that the Bush administration had offered to justify its aggressive use of force against Iraq a decade earlier. After voting in favour of a (vetoed) Security Council resolution to call out Russia’s act of aggression, the Kenyan ambassador to the UN reminded the gathered diplomats of “the justifications for past interventions by other powerful States… Even as deserved condemnations ring out today about the breach of Ukraine’s sovereignty, history’s condemnations are allowed silence in this room”. The damage that Merz and Steinmeier have inflicted on both Germany’s international credibility and the order put in place with the founding of the United Nations will likewise be felt for decades to come. As things stand right now, as far as the jus contra bellum is concerned, there might not be much left to reconstruct when the community of international law scholars meets up in Berlin in September. In that, the realists may find reason to rejoice. They, too, will come to miss it once it’s gone.

The post What We Lost in the Skies Above Tehran appeared first on Verfassungsblog.

Corporations, especially those engaged in fossil fuel production, agriculture, construction, and transportation, play a significant role in the climate crisis and in its human rights impacts. Holding businesses responsible for their human rights and environmental harms has been a perennial challenge that has become increasingly acute in the climate crisis. While human rights law conceptualizes States as primary duty bearers, many multinational corporations (MNCs) hold power and resources to rival small States. Many of these transnational enterprises have long manipulated jurisdictional loopholes and weaponized international trade and investment law to evade accountability. Some have even sought to penalize States that try to improve human rights and environmental standards in ways that conflict with corporate interests. It is thus of critical importance that the Inter-American Court of Human Rights (IACtHR)’s Advisory Opinion 32/25 (AO-32/25) not only directly addresses corporate climate and human rights impacts, but also provides some pathways forward on these persistent barriers to accountability. This blog discusses AO-32/25’s holdings and innovations as related to business and human rights and reflects on their broader legal implications.

A Call to States to Strengthen Domestic Legal Frameworks

Because States are indeed the primary duty bearers under human rights law, AO-32/25’s roadmap for addressing corporate conduct that damages the global climate system hinges primarily on holding States accountable for failing to adequately regulate and oversee third-party actors. The opinion outlines detailed requirements for States to “adopt legislative and other measures to prevent human rights violations committed by public and private enterprises” (para. 345). While these provisions don’t address corporations directly, they have serious implications for them. The AO requires binding domestic instruments to advance corporate due diligence and transparency and to combat corporate greenwashing.

Requiring Due Diligence 

Not only does AO-32/25 mandate States to pass legislation codifying corporate human rights and climate due diligence requirements, it also provides detailed guidance on what that due diligence should look like (para. 348). Due diligence processes must: (1) apply throughout companies’ supply chains; (2) be subject to continuous monitoring; (3) ensure public access to information; and (4) guarantee adequate pathways for public participation and accountability. In this respect, AO-32/25 builds on momentum from the European Union’s Corporate Sustainability Due Diligence Directive and recent Due Diligence laws in several European Union countries. Thus, for multinational corporations (MNCs), due diligence is no longer a mere quirk of operating in the European Union: it is a multijurisdictional legal requirement.

Mandating Transparency 

AO-32/25 requires States to obligate companies to make public certain information in their possession, including on: (1) greenhouse gas (GHG) emissions in their supply chains; and (2) the implementation of due diligence (para. 349). Here, the IACtHR builds on the Regional Agreement on Access to Information, Public Participation and Justice in Environmental Matters in Latin America and the Caribbean (Escazú Agreement), which requires States to “promote access to environmental information in the possession of private entities” (Art. 12). Given that oil and gas companies knew more about climate impacts than State actors for decades and not only failed to make this information public, but actively sowed disinformation, these transparency requirements are essential.

Combatting Greenwashing and Corporate Influence

Corporate actors also contribute to the climate crisis and related human rights harms by seeking to mask the damage they cause through greenwashing: performative environmental action or rhetoric. AO-32/25 requires States to adopt norms to combat greenwashing and corporate influence in climate policy and regulation (para. 347). These specific provisions regarding the regulation of corporate behavior are complemented by AO-32/25’s robust call for states to combat disinformation on the climate crisis (paras. 524-529).

Centering Procedural Rights

Human rights protection in the context of development projects often hinges on the mechanics of public participation, consultation, and consent. AO-32/25’s focused attention on procedural and participation rights (paras. 458-587) therefore has critical implications for corporate accountability. Adopting the logic of its judgment in Case of the Inhabitants of La Oroya v. Peru, the IACtHR emphasizes that when measures adopted by either States or private actors may “affect the rights of a specific group,” it is “imperative that such group be afforded an effective opportunity to be heard and to participate in decision-making.” (paras. 537-538). AO 32/235 clarifies that authorities must, inter alia: (1) be guided by “consensus and decisions reached through participatory processes” (para. 538); (2) explain how they considered public input (para. 538); (3) actively promote the participation of Indigenous, Afro-descendent, peasant farming, and fishing communities (para. 539); and guarantee participation not only at the start of the project, but throughout project monitoring and due diligence procedures (para. 349).

Buttressing a Regulatory Approach: Multijurisdictional Regulation and HRD Protection

While a framework grounded in a continued focus on States as duty bearers cannot fully escape the Realpolitik of MNCs as quasi-States, AO-32/25’s emphasis on State obligations to regulate both the companies that are domiciled in their territory and those that operate within them (para. 347) is a promising step forwards. This provision explicitly opens multiple frontiers to regulate the behavior of MNCs operating in the Americas. For example, in the case of a Canadian mining company with extractive projects in Peru and Bolivia, all three countries–Canada, Peru, and Bolivia–have a duty to regulate. The failure of countries in the Global North where MNCs are often domiciled to adequately regulate their activities has been a major loophole exploited by corporate actors, allowing them to create judgment-proof subsidiaries abroad and evade jurisdiction at home. The provision also has important implications for countries like Panama and the Cayman Islands, which have traditionally tried to incentivize corporations to domicile with the promise of low financial transparency; AO-32/25’s regional reach means even these “secrecy jurisdictions” will be required to improve key transparency metrics.

AO-32/25 also requires that States  take measures to support the actions of human rights defenders (HRDs) with regard to corporate actors (para. 347)  which is also an essential complement to its focus on regulation. It is well documented that land, environmental, and climate defenders are most likely to be attacked when their advocacy intersects with “large business projects.” Increased regulation can only be effective when civil society and communities can safely denounce regulatory violation. Here too, AO-32/25 echoes the Escazú Agreement, weaving together transparency, regulation, and protection for HRDs. A dedicated section of the opinion (paras. 561-587) details recommendations regarding the “special duty of protection” (para. 566) of HRDs, which “imposes on the authorities an enhanced obligation to devise and implement appropriate public policy instruments, and to adopt the pertinent domestic legal provisions and practices to ensure the free and safe exercise of the activities of human rights defenders” (para. 562). The IACtHR’s reiteration of State obligations to support HRDs in the section addressing corporate actors is appropriate given the intimate link between corporate exploitation and corruption and killings, disappearances, criminalization, and harassment of HRDs.

Introducing Differentiated Corporate Obligations

In line with the IACtHR’s existing jurisprudence, as well as the Inter-American Standards on Business and Human Rights, AO-32/25 reiterates that businesses themselves have “obligations and responsibilities” regarding the climate crisis (para. 346). The IACtHR states, “business enterprises should prevent their activities from causing or contributing to human rights violations, and must take measures to remedy any such violations” (para. 345). In addition to emphasizing the duty of States to establish adequate legal frameworks to constrain corporate behavior (as explored above), the IACtHR also proposes an innovative approach to corporate accountability: applying the principle of common but differentiated responsibilities and respective capabilities (CBDR-RC) to corporate actors.

A foundational principle of international environmental law, CBDR-RC was established in the United Nations Framework Convention on Climate Change (UNFCCC). Article 3(1) of the UNFCCC was designed to recognize States’ varying levels of historic responsibility for GHG emissions and varying capacity to address climate change impacts. Despite its foundational character and frequent invocation, there have been a number of recent challenges regarding the principle’s effectiveness and implementation. Developing countries charge that historically high emitters are shirking their mitigation and finance responsibilities, while developed countries argue that developing countries should start bearing more of the burden of climate action.

The IACtHR, however, may breathe new life into the CBDR-RC principle by extending it to corporations (para. 350). According to the IACtHR, “[i]n the context of the climate emergency . . . while all companies can contribute to meeting mitigation targets, some of them have a greater responsibility because of the risk created by the activities they carry out.” The IACtHR holds that “States should establish differentiated climate action obligations based on the current and historical contribution of companies to climate change and impose stricter duties on companies that engage in activities that generate higher GHG emissions.” This holding reaffirms the conclusion already reached by the Philippines Human Rights Commission, that there is a human rights basis for holding the Carbon Majors accountable for their outsized contribution to climate change, and recognizes that a one-size-fits-all approach to corporate climate accountability is unlikely to be effective or just.

Setting Up a Showdown with Investment Law

AO-32/25 directly wades into a long-boiling international law conflict between human rights law and environmental law, on the one hand, and investment and trade law, on the other. Free trade agreements (FTAs) and Bilateral Investment Treaties (BITs) frequently allow corporations to sue national governments in the Investor-State Dispute Settlement (ISDS) system, where only investors have rights. Investors can seek massive payments based on “indirect expropriation”: claims that national laws or policies negatively impact their investments, “legitimate expectations”, and future profits. As of 2023, countries in the Americas had faced 401 such suits and either “been ordered or agreed to pay investors 29.2 billion in awards and settlements.” Such proceedings are overwhelmingly brought by investors based in the Global North (U.S. investors alone account for 17.7% of complaints filed in ICSID) and disproportionately impact States—and their citizens—in the Global South. Proceedings often focus narrowly on States’ obligations under specific trade and investment law provisions, without any consideration for States’ competing legal obligations under international environmental and human rights law, including commitments made pursuant to the Paris Agreement.

The ISDS system is frequently weaponized by the mining, gas, and oil industries. In numerous cases, ISDS provisions have been used to challenge climate-protective regulations, including measures aimed at phasing out fossil fuels. As the damages awarded to companies in these cases can total in the billions, the potential for litigation exerts a chilling influence on governments considering regulations to better protect people and the environment. The IACtHR recognizes the risk of this “regulatory chilling effect” (paras. 163-164) and tackles the challenge that ISDS poses to effective climate action head-on: “States should revise their trade and investment agreements, as well as Investor-State Dispute Systems, to guarantee that they neither limit nor restrict efforts in the area of climate change and human rights” (para. 351).  

The IACtHR’s pronouncement that taking actions “to stop anthropogenic behaviours that critically threaten the balance of our planetary ecosystems” is a jus cogens obligation (para. 291) may bolster States’ ability to defend their climate policies within the ISDS system. The jus cogens designation is reserved for “peremptory norms of international law” that “are universally applicable and are hierarchically superior to other rules of international law.” While the IACtHR’s jus cogens analysis does not specifically address corporate action, the holding nonetheless provides significant support for State action to regulate corporate climate harms. By clarifying this international legal obligation explicitly, AO-32/25 strengthens States’ legal basis for defending against investor claims that climate-protective policy actions negatively affect their interests. States in the Americas can point to the AO to argue that their obligation to undertake climate action is “hierarchically superior” to their obligations under international trade and investment law.

Addressing the inequities and injustices of ISDS is essential to ensuring that effective climate action can proceed in the Americas. The fact that AO-32/25 directly addresses this point, coupled with its clarification of the jus cogens status of certain climate obligations, offers important tools. Critically, these provisions may influence more States to join the trend of renouncing ISDS in treaties. For as long as States continue to participate in the system, the efficacy of AO-32/25’s provisions may hinge in large part on arbitration tribunals themselves. Governed by discretion and “subject neither to precedent nor any meaningful appeal,” arbitration panels have long ignored international human rights and environmental law with little recourse. However, States can create pressure within the system by adopting key provisions from AO-32/25 as part of their legal defense. International law practitioners and scholars can aid in this effort through increased efforts to utilize the amicus curiae mechanisms in trade tribunals to highlight the implications of such cases for States’ international human rights and environmental obligations. While arbitration panels also have discretion to accept or reject amicus interventions, such broadened and heightened effort may convey that the system is not operating in the shadows and push tribunals to take into account the totality of international law and States’ overlapping legal obligations.

Conclusion

As firmly established by the IACtHR, “the adverse effects of climate change are, and will increasingly become, pervasive across all aspects of human life worldwide. These adverse effects constitute threats to and violations of human rights” (para. 118). As significant contributors to these adverse effects, corporations, especially large corporations in GHG emissions-intensive industries, bear significant responsibility for human rights harms associated with climate change. They must be held accountable for their role, and contribute to efforts to mitigate climate-related harms. AO-32/25 provides important new tools for those who seek to ensure corporate climate accountability and enable meaningful corporate climate action.

The post Corporations, Climate, and the Court appeared first on Verfassungsblog.

“An existential threat” – this is how the International Court of Justice (ICJ) characterized climate change in its long-awaited advisory opinion on the obligations of States with respect to climate change. In the most significant development in international climate law since the adoption of the Paris Agreement, the ICJ outlined numerous obligations that could significantly shape the contours of international environmental law and global climate governance.

The ICJ’s message is clear: climate obligations are not aspirational – they are legal, substantive, and enforceable. Drawing from an array of legal sources and rejecting arguments based on the lex specialis principle aimed at limiting the rules applicable to climate governance, the ICJ affirmed that States have binding obligations to prevent significant environmental harm, cooperate internationally, and uphold fundamental rights in the face of escalating climate risks. These duties extend to all states, and the climate system must be protected for present and future generations.

Among the most consequential aspects of the opinion is the Court’s articulation of a stringent due diligence standard. Based on the scientific consensus as established in the work of the Intergovernmental Panel on Climate Change (IPCC) – understood as “the best available science on the causes, nature and consequences of climate change” (para. 74) – states must act urgently. This includes not only setting and updating robust national climate plans under the Paris Agreement but also regulating private actors and providing support to more vulnerable nations. Inaction, or failure to act decisively, may constitute an internationally wrongful act – triggering consequences under the law of state responsibility.

Strikingly, the ICJ adopted the entire operative part of the opinion unanimously – a rare feat that underscores the global consensus around the legal obligations at stake. With climate litigation surging globally, the Court has laid down a clear and united marker: climate obligations are real, and the law has a role to play.

There is no question that the ICJ’s advisory opinion will shape climate governance in the years to come. The specific ways in which it will influence policy and practice will undoubtedly become the focus of intense debate across academia, courts, bureaucracies, and civil society in the months and years ahead.  But before that, the advisory opinion must be analyzed and discussed in its various dimensions. For this reason, the Sabin Center for Climate Change Law’s Climate Law Blog and Verfassungsblog are launching a joint blog symposium, inviting leading experts to analyze selected aspects of the advisory opinion. This introductory blog post briefly outlines the background of the advisory opinion and the ICJ’s most important findings, setting the stage for the discussion ahead.

From Vanuatu to The Hague

Requested by the United Nations General Assembly following a campaign initiated by law students at the University of South Pacific, then led by Vanuatu and supported by over 130 states, the opinion marks the first time the ICJ has authoritatively interpreted the legal duties of States in relation to climate change mitigation, adaptation, and transboundary harm (for background, see here and here).

Prior to issuing its advisory opinion, the ICJ received over a hundred  written and oral submissions, which revealed both unprecedented global engagement with the legal dimensions of the climate crisis and deep divisions over how international law should respond (see here, here, and here). Nearly 100 States and multiple international organizations participated in the ICJ’s proceedings, offering sharply contrasting views on the applicable legal framework, the content and reach of States’ obligations, and the legal consequences of climate harm.

The submissions reflected competing legal paradigms: one that views international law as a living tool for advancing climate justice and accountability, and another that emphasizes legal caution, treaty limits, and political sensitivities. The ICJ’s opinion was expected to navigate these tensions carefully – seeking legal clarity while acknowledging the complexity of the climate crisis and its evolving legal terrain. Instead, the ICJ’s responses went far beyond this careful approach, delivering a bold and far-reaching opinion, which is poised to influence climate policy well into the future.

Scope of State Obligations and Legal Framework Clarified

The ICJ began by noting that it had jurisdiction to hear the case and that there were no compelling reasons to decline to answer the questions submitted by the General Assembly. It also reviewed the relevant scientific literature, drawing heavily from the work of the IPCC. Thereafter, the ICJ addressed the question of the “most directly relevant applicable law” that governs the questions (paras. 113 ff). The ICJ identified a comprehensive legal framework that includes the Charter of the United Nations, climate change treaties (such as the United Nations Framework Convention on Climate Change (UNFCCC), Kyoto Protocol, and Paris Agreement), the United Nations Convention on the Law of the Sea (UNCLOS), and other environmental treaties like the Ozone Layer Convention, the Montreal Protocol, the Kigali Amendment to the Montreal Protocol, the Convention on Biological Diversity, and the Convention to Combat Desertification. Customary international law duties also come into play, especially the duty to prevent significant harm to the environment (paras. 132-139) and the duty to cooperate for environmental protection (paras. 140-142). Notably, the ICJ found that international human rights law is part of the most directly relevant applicable law, including rights to life, health, housing, food, and a clean, healthy, and sustainable environment. Other principles, such as the principles of sustainable development, common but differentiated responsibilities and respective capabilities (CBDR-RC), equity, intergenerational equity, and the precautionary principle are also applicable (para. 161).

No Legal Silos: The ICJ on Lex Specialis

The ICJ rejected the argument made by some states – including the United States – that climate change treaties constitute lex specialis and therefore render other rules of international law inapplicable (paras. 162-171). Lex specialis is a principle of legal interpretation used to determine whether a more specific rule takes precedence over a more general one, or whether the two rules apply concurrently. The ICJ relied on the work of the International Law Commission, which states that mere overlap in subject matter does not automatically trigger the application of lex specialis. For the principle to apply, there must be either a real inconsistency between two legal provisions or clear evidence that one was intended to exclude the other. The ICJ found no inconsistency between climate treaties, such as the UNFCCC and the Paris Agreement, and other relevant rules and principles of international law. In fact, both treaties explicitly refer to other legal frameworks in their preambles, indicating that they are intended to operate within, rather than outside, the broader international legal system (paras. 168-170).

Due Diligence Over Discretion

Among the most consequential aspects of the opinion is the Court’s articulation of a stringent due diligence standard. In light of the scientific consensus, states must act urgently. This includes not only setting and updating robust national climate plans under the Paris Agreement but also regulating private actors and providing support to more vulnerable nations. Inaction, or failure to act decisively, may constitute an internationally wrongful act, triggering consequences under the law of state responsibility.

The ICJ found that the discretion of parties to the Paris Agreement in preparing their Nationally Determined Contributions (NDCs) is limited (paras. 237-249). Under the Paris Agreement, each party is required to submit NDCs outlining efforts to reduce greenhouse gas emissions and adapt to the impacts of climate change. Some States argued that NDCs fall entirely within the discretion of each State party. The ICJ disagreed. It held that parties are under an obligation to exercise due diligence when preparing their NDCs, ensuring that, when taken together, they achieve the 1.5°C temperature goal  (para. 245).

Customary International Law and the Climate System

The ICJ held that the customary duty to prevent significant harm to the environment applies fully to the climate system. Crucially, this duty applies to all States, including those that are not parties to climate change treaties. As a vital part of the global environment, the climate system must be protected for present and future generations (para. 273). The risk of significant environmental damage must be assessed based on the likelihood and magnitude of potential harm. Furthermore, the ICJ recognized that significant harm can also arise from the cumulative impacts of multiple activities – both by states and non-state actors (para. 276).

The standard of conduct required is due diligence – a flexible, context-sensitive obligation shaped by a range of legal and scientific considerations. The ICJ identified several key elements that define how due diligence must be understood in the climate context (paras. 281-299). These include: (i) the adoption of appropriate legal and regulatory measures, such as effective policies aimed at achieving deep, rapid, and sustained reductions in greenhouse gas emissions; (ii) the availability and assessment of scientific and technological information, which states are expected to  acquire and analyze actively; and (iii) the relevance of both binding and non-binding norms, including decisions by the Conferences of the Parties (COPs) to climate treaties and recognized technical standards and best practices.

In addition, the ICJ stressed: (iv) the CBDR-RC principle, noting that states with greater resources and governance capacity are expected to exercise a higher standard of care, though all states must act within the limits of their capabilities; (v) the necessity of taking preventive action even amid scientific uncertainty, which should not be used as a pretext for delay or inaction; (vi) the requirement that states undertake thorough risk and impact assessments for proposed activities within their jurisdiction that may contribute to climate harm, based on the best available science; and (vii) the obligation to notify and consult in good faith with other states when activities may create a risk of significant transboundary harm or interfere with collective climate efforts.

The ICJ also reaffirmed the customary duty to cooperate, emphasizing that international collaboration is essential when addressing a global commons like the climate system (paras. 301-302).

While states maintain discretion in how they regulate greenhouse gas emissions, this does not exempt them from legal accountability (para. 306). Discretion must be exercised in good faith and in accordance with the required level of due diligence.

Protection of the Marine Environment, Sea Level Rise, and Statehood

The ICJ identified UNCLOS as one of the instruments most directly relevant to the questions submitted to it by the General Assembly. The Court recalled the advisory opinion rendered by the International Tribunal for the Law of the Sea (ITLOS) last year (see here), noting that it would “ascribe great weight to the interpretation adopted by the Tribunal” (para. 338). In this light, the ICJ reaffirmed that anthropogenic greenhouse gas emissions fall within the definition of marine pollution under Article 1, paragraph 1, subparagraph 4, of UNCLOS, which means that Part XII of UNCLOS on the protection of the marine environment is applicable to climate governance (paras. 339-340).

The ICJ found that States have both positive and negative obligations under UNCLOS: they must take active steps to protect and preserve the marine environment (Article 192) and avoid degrading it (paras. 342-343). This includes taking all necessary measures to prevent, reduce, and control marine pollution (Article 194), even if complete prevention is not immediately achievable. The ICJ emphasized a stringent standard of due diligence, requiring States to act based on the best available science and their capabilities (paras. 345-349). It also underscored States’ obligations to cooperate under Article 197 (paras. 350-351), to conduct environmental impact assessments when planned activities pose significant risks under Article 206 (paras. 352-353), and to support research and data sharing under Articles 200-201 (para. 351). The Court stressed that UNCLOS and other rules of international law “inform each other” and must be applied hand in hand (para. 354).

The ICJ also addressed concerns about sea level rise, particularly its impact on maritime territories and the statehood of small island States. It found that UNCLOS does not require states to revise established baselines or maritime boundaries due to physical changes like coastal recession (para. 362). Thus, existing maritime entitlements remain valid even as sea levels rise. More fundamentally, the ICJ found that “once a State is established, the disappearance of one of its constituent elements would not necessarily entail the loss of its statehood” (para. 363). In other words, according to the ICJ, the complete submergence of a territory does not necessarily negate a State’s legal status. This confirmation of the existence of a presumption of continuity of statehood will undoubtedly be welcomed by the States most immediately affected by sea level rises, but it is unfortunate that the Court did not elaborate further on this important finding, as deplored by Judge Peter Tomka and Judge Bogdan Aurescu.

International Human Rights Law and the Climate

The ICJ underscored the indivisibility of climate justice and human rights. It recognized that a stable climate is foundational to the enjoyment of numerous rights, including the rights to life, health, food, water, and housing (paras. 373ff). Climate vulnerable groups such as children, women, and indigenous peoples were given special attention by the Court (paras. 382ff), which also clarified that states have obligations under the principle of non-refoulement when there is a real risk of irreparable harm to life, citing the Human Rights Committee’s decision in Teitiota v. New Zealand (para. 378). Remarkably, the Court went on to describe a clean, healthy, and sustainable environment as “a precondition” for the enjoyment of human rights, and that the right to such an environment “results from the interdependence between human rights and the protection of the environment” and is “therefore inherent in the enjoyment of other human rights” (para. 393).

Reaffirming that human rights treaties may apply extraterritorially when a State exercises jurisdiction outside its borders (paras. 394ff), the ICJ once more stressed that international human rights law, climate change treaties, and environmental agreements are mutually reinforcing and “inform each other” (para. 404). Therefore, when implementing obligations under one body of law, states must consider and harmonize their responsibilities under the others.

State Responsibility and Reparations

While acknowledging the complexity of climate change in terms of its causality, temporal scope, attribution, and causation, the ICJ did not shy away from affirming that reparations are warranted when acts or omissions can be attributed to a state, giving rise to state responsibility. In particular, the ICJ affirmed that “[f]ailure of a State to take appropriate action to protect the climate system from [greenhouse gas] 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.” (para. 427).

The ICJ further held that when a State fails to meet its international obligations related to climate change – whether under treaty law, customary international law, or human rights law – it incurs responsibility under the law of state responsibility (para. 444), triggering “a panoply of legal consequences” (para. 445). These include obligations of (i) cessation and non-repetition, (irrespective of harm) and (ii) full reparation, including restitution (returning things to the status quo ante, if possible), compensation (for financially assessable damage) and/or satisfaction (for moral or non-material harm). The Court also noted that breaches of states’ obligations do not affect the continued duty of the responsible state to perform the obligation breached.

The ICJ confirmed that these remedies can apply for wrongful acts caused by cumulative greenhouse gas emissions (para. 429) or failures to regulate private actors (para. 438), provided they constitute a breach of an international obligation. These obligations are erga omnes – owed to the international community as a whole (paras. 439ff). This means that any state may invoke responsibility, not just injured states.

A Clear Message

As contributors to this symposium will explore in the coming days, the opinion’s true legacy may lie not only in its legal conclusions, but in its power to influence political will, guide national courts, and support vulnerable communities seeking justice. Amid a global surge in climate-related lawsuits, the ICJ has sent a clear message: legal systems must reckon with climate duties, and action can no longer be deferred.

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