1. Negotiating Bonn
The 62nd sessions of the Subsidiary Bodies (SB-62) to the United Nations Framework Convention on Climate Change (UNFCCC),Footnote 1 also known as the Bonn Climate Change Conference, held from 16 to 26 June 2025, served as a critical waypoint between the 28th Conference of the Parties (COP-28) in Dubai (United Arab Emirates) and the forthcoming COP-30 in Belém (Brazil). Convened at the UNFCCC headquarters in Bonn (Germany), the sessions of the Subsidiary Body for Scientific and Technological Advice (SBSTA) and the Subsidiary Body for Implementation (SBI) were intended to consolidate technical progress on the implementation of the Paris Agreement.Footnote 2 Instead, these sessions exposed, repeatedly and often in stark terms, the fragility and fragmentation of the global climate governance architecture.
The Bonn Conference opened amid controversy: the proceedings were delayed by more than 30 hours because of disputes over the inclusion of Article 9(1) of the Paris Agreement, on the financial obligations of developed countries, as a stand-alone item in the agenda.Footnote 3 This procedural standoff reflected deeper structural tensions between developed and developing countries over historical responsibility, equity, and the legitimacy of agenda setting within the multilateral process.Footnote 4
The negotiations spoke to matters that lie at the operational core of the Paris Agreement, including adaptation, mitigation, carbon markets, and climate finance. Adaptation-related discussions focused on the Baku Adaptation Roadmap, which seeks to make progress towards the Paris Agreement’s global goal on adaptation (GGA).Footnote 5 Here, parties were divided over the question of whether the GGA should prioritize quantitative indicators or transformative processes.Footnote 6 Developing countries pushed for the inclusion of indicators that address broader systemic vulnerabilities and enablers, such as finance and governance capacity, while several developed countries sought to streamline measurable outcomes into the list.Footnote 7
The Mitigation Work Programme (MWP), a process created to strengthen near-term mitigation action, remained gridlocked because of dissension over whether it should deliver prescriptive outcomes or continue to facilitate technical exchange.Footnote 8 Some of the discussions revolved around the development of a digital platform for the implementation of mitigation actions.Footnote 9 The parties further continued with negotiating the design and governance of carbon-market mechanisms and non-market cooperation under Article 6 of the Paris Agreement. They paid particular attention to environmental integrity, corresponding adjustments, and benefit-sharing provisions. Contentious debates also emerged concerning levels and sources of climate finance.Footnote 10 Developing countries renewed calls for clearer and more predictable financial flows, as well as for progress on the new collective quantified goal (NCQG) and the integration of priorities for adaptation into financial mechanisms.Footnote 11 The tensions around the NCQG reflect long-standing disputes about the volume of climate finance and the form of its disbursement – grants versus loans – as well as about the balance between mitigation and adaptation.Footnote 12
Taken together, these negotiations illustrate the limitations of state-centric processes unfolding within the large landscape of contemporary climate governance defined by plurality and polycentricity. While the Bonn negotiations remain a key venue for international climate diplomacy, they also underscore how limited progress within formal UNFCCC channels has spurred a diversification of actors and forums. As a result, states are no longer the sole architects of climate law. Courts, cities, Indigenous communities, regional coalitions, and epistemic networks made up of scientists, policymakers, and activists increasingly shape legal norms and governance practices, often outside or alongside UNFCCC processes. This legal diversification is not merely institutional; it is conceptual. Climate law blends soft law and binding obligations, domestic litigation and global targets, and economic instruments and moral principles.
This Editorial situates the 2025 Bonn negotiations within the broader currents of legal evolution and epistemic reorientation that are shaping climate law in the Anthropocene. The Bonn discussions of adaptation metrics, mitigation ambition, cooperative mechanism, and financial accountability resonate strongly with the contributions that appear in this issue of Transnational Environmental Law (TEL). Articles on intergenerational justice, transnational legal education, environmental and climate impact assessments, trade law, and the polluter pays principle highlight the ways in which law is being stretched, reinterpreted, and regrounded by practitioners and scholars alike.
In this Editorial, the presentation of the contributions in question is structured around the core tensions and innovations that emerged from the Bonn negotiations. We begin with Roger Merino’s discussion of sovereignty, commons, and Indigenous rights,Footnote 13 which grounds this issue of TEL in the power asymmetries and governance challenges that are exemplified by the 30-hour agenda stand-off and by the letter of the incoming Brazilian Presidency of COP-30 to the international community.Footnote 14 That letter calls on negotiators to rebuild a ‘global infrastructure of trust’,Footnote 15 urges a shift from adversarial diplomacy to cooperative engagement, and emphasizes the central role of Indigenous peoples, adaptation, and implementation-focused multilateralism – highlighting both the aspirations and the systemic strains of today’s climate governance.
The educational and representational implications of these divides, as they manifest in transnational legal clinics, are discussed by a group of law clinic collaborators from Canada and Peru: Leanna Katz, Andrea Mariana Dominguez, Mees Brenninkmeijer, Oscar Bourgeois, Narain Yücel, Nadia Alitu Blas Rodriguez, Luis Alejandro Pebe Muñoz, Gianella Mariana Livia Riquero, Carla Arbelaez and Ilana Cohen.Footnote 16 They explain how the next generation of climate diplomats must navigate procedural injustice and the north–south asymmetry.
Next, Ben Chester Cheong’s analysis of intergenerational justice and climate jurisprudenceFootnote 17 builds on this foundation, moving from education to legal theory. Ling Chen’s analysis of subnational climate clubs shows how legal innovation is increasingly bottom-up, polycentric, and pluralist.Footnote 18 We then move to implementation: Benoit Mayer proposes climate effect assessments (CEAs) as a method for linking adaptation and mitigation.Footnote 19 Ling Zhu and Xinwei Li’s application of the polluter pays principle addresses attribution and accountability in complex systems;Footnote 20 and Sherzod Shadikhodjaev explores the ways in which environmental impact assessments (EIAs) in trade regimes can expand the climate accountability toolkit.Footnote 21 Finally, Harri Kalimo, Simon Happersberger and Eleanor Mateo present their concept of ‘flexilateralism’ to illustrate how hybrid legal strategies now drive climate-trade interactions.Footnote 22
2. Pluralism and Legal Positivism
As COP-30 approaches, legal thinking must evolve to meet the challenge of justice, enforceability, and global interdependence. The failure to treat Article 9(1) of the Paris Agreement as a stand-alone item on the agenda reflects enduring power asymmetries.Footnote 23 As Roger Merino reminds us, governance models that are rooted in state sovereignty and international cooperation can marginalize both Indigenous ontologies and the voices of future generations. Merino’s article, ‘Governing International Commons: Re-examining Environmental and Sovereignty Imaginaries in the Amazon’,Footnote 24 shows how the Amazon is governed by overlapping and often conflicting principles such as enclosure, common heritage of humankind, and common concern of humankind, which are embedded in the practices of the Amazon Cooperation Treaty Organization (ACTO). While the international community increasingly treats the Amazon as a ‘global carbon reservoir and climate regulator’,Footnote 25 the Amazon Basin states consistently reject its ‘internationalization’.Footnote 26 Instead, they assert sovereign rights to use the forest according to their development agendas. This sovereignty claim, however, often sidelines the rights of Indigenous peoples.Footnote 27 Merino identifies three key governance principles that structure discourse on international commons. Enclosure represents the principle of absolute state sovereignty.Footnote 28 Common heritage of humankind suggests global ownership and shared responsibility, which are typically inapplicable in areas under national jurisdiction.Footnote 29 Common concern of humankind enables international engagement without undermining sovereignty by positioning ecological protection as a shared ethical responsibility.Footnote 30 Merino critiques these principles because they share problematic assumptions: they are anthropocentric,Footnote 31 ethnocentric, and state-centric, and their grounding in Western juridico-political thought means that they are liable to exclude Indigenous ontologiesFootnote 32 and to deny Indigenous nations the status of legitimate political actors.Footnote 33 Even when Indigenous land rights are recognized nominally, they do not entail real decision-making power.Footnote 34
Merino highlights the growing demands of Indigenous organizations such as the Coordinating Body of Indigenous Organizations of the Amazon Basin. Leaders such as Nemonte Nenquino and Olivia Bisa treat the forest not just as a resource but as a living world in need of protection.Footnote 35 These Indigenous cosmovisions challenge the legitimacy of state-centric and international environmental governance models. Merino argues that acknowledging these perspectives would require us to rethink sovereignty itself and to integrate Indigenous political agency into governance institutions such as the ACTO.Footnote 36 The article draws on Third World Approaches to International Law (TWAIL) and decolonial theory, which reveal that international and domestic governance excludes non-Western epistemologies and sustains global inequities.Footnote 37 Merino concludes that the current governance of the Amazon is fragmented and contradictory: states use the language of cooperation and environmentalism while reinforcing extractive and exclusionary models. By reimagining the core governance principles of enclosure, common concern, and common heritage through the lens of Indigenous self-determination and decolonial ethics, Merino’s article calls for a transformation of the governance of the international commons.
The 30-hour procedural stand-off at Bonn was not merely a scheduling dispute. It revealed enduring north–south tensions over voice, priority setting, and the meaning of procedural fairness. Developing countries framed the exclusion of a stand-alone finance item as a structural erasure of their core concerns, while the developed country parties insisted on cross-cutting integration. These tensions are also pertinent to the arguments in ‘Transnational Legal Clinic Collaboration: A Force in Global Climate Litigation’, by Leanna Katz, Andrea Mariana Dominguez, Mees Brenninkmeijer, Oscar Bourgeois, Narain Yücel, Nadia Alitu Blas Rodriguez, Luis Alejandro Pebe Muñoz, Gianella Mariana Livia Riquero, Carla Arbelaez and Ilana Cohen. The authors show how transnational legal clinics are becoming critical training grounds for the next generation of climate diplomats and legal advocates. They argue that transnational legal clinics can educate future legal professionals and contribute meaningfully to global climate litigation. By drawing on the experience of a collaborative amicus curiae brief by students from McGill University (Montreal, Canada) and the Pontifical Catholic University (PUCP) (Lima, Peru), they explore the structural, pedagogical, and legal dimensions of clinical legal collaboration in the context of climate justice.
Clinics have evolved from community-based efforts that focus on social justice to international human rights clinics. Now, they are becoming transnational.Footnote 38 Transnational legal clinics teach not only international law but also a transnational legal process methodology for navigating various legal norms – public and private, binding and non-binding – and multiple legal orders.
The key case study in the article is Álvarez v. Peru,Footnote 39 a groundbreaking Peruvian climate case brought by young plaintiffs who were seeking to halt the deforestation of the Amazon on constitutional and human rights grounds.Footnote 40 The Canadian and Peruvian law clinics collaborated on an amicus brief that contains comparative insights from global climate litigation.Footnote 41 Although the Superior Court of Justice of Lima ultimately dismissed the claims, it admitted the amicus brief and issued recommendations to several government bodies accordingly.Footnote 42 The students engaged in experiential learning and reflected on the ethical and political dynamics of north–south collaboration. Drawing on Bonilla’s critique of hierarchical partnerships,Footnote 43 Katz and her co-authors acknowledge the inherent power imbalances between institutions from the global north and south. These imbalances pertain to resource endowments, language, and academic authority. Adopting a transnational and solidarity-based framework can mitigate these structural issues. In the McGill-PUCP collaboration, the Peruvian clinic proposed the amicus brief and led on substantive legal expertise, thus challenging typical north–south asymmetries.Footnote 44 The students described the collaboration as a space for mutual learning and critical reflection.Footnote 45 Katz and her co-authors argue that collaborations of this kind are both pedagogically innovative and legally effective. The article ultimately frames legal clinics as transformative spaces for building solidarity, fostering legal pluralism, and empowering the next generation of climate advocates.Footnote 46
In ‘Bending the Arc of Law: Positivism Meets Climate Change’s Intergenerational Challenge’, Ben Chester Cheong explores the jurisprudential tension between legal positivism and intergenerational climate justice. Seeing as the negotiations in Bonn wrestled with questions of metrics, indicators, and transformative adaptation, Cheong’s call for a reformulated legal positivism that absorbs sustainability as a constitutive element of the rule of law gains much resonance. He points to means of reforming the traditional positivist view, which maintains a strict separation between law and morality and thus obstructs the recognition of obligations to future generations.Footnote 47 The themes in Cheong’s work are in evidence in the diplomatic strategies and equity debates that were negotiated in Bonn at SB-62.
Cheong’s central thesis is that courts are increasingly compelled to address the temporal demands of climate change, which implicate the rights and interests of future generations, even in legal systems that are grounded in positivist traditions. He identifies three key strategies that the courts have used to integrate intergenerational justice: (i) the dynamic interpretation of existing positive rights, (ii) the application of constitutional clauses that refer to future generations, and (iii) procedural innovations that enable the representation of future interests.Footnote 48 These strategies see use not only in courtrooms but also in multilateral fora. The Bonn negotiations underscore the need to embed intergenerational justice more firmly within the operational and normative architecture of international climate law.Footnote 49
Cheong notes that while exclusive legal positivism struggles to accommodate moral reasoning, inclusive legal positivism, as it appears in the works of WaluchowFootnote 50 and Shapiro,Footnote 51 offers pathways for the incorporation of moral principles into law through social recognition.Footnote 52 Still, the interpretation of value-laden provisions often exceeds what can be accounted for by positivism alone, which reveals the limitations of the latter when it is confronted with the unique demands of the Anthropocene.Footnote 53 Cheong thus proposes two complementary strategies. Firstly, contextual constitutionalism, whereby judges engage in moral reasoning within the boundaries of constitutional texts and precedent, would allow positive law to respond dynamically to climate realities.Footnote 54 Secondly, a reformulated positivism would acknowledge sustainability as a necessary component of the rule of law.Footnote 55 Cheong’s conclusion is that while legal positivism may initially appear ill-suited for intergenerational climate claims, it can evolve. The courts must embrace a form of interpretive flexibility that retains fidelity to legal sources while responding to novel moral imperatives.
In ‘Subnational Climate Clubs: An Interactional Approach to Transnational Lawmaking’,Footnote 56 Ling Chen’s argument for the recognition of subnational climate clubs as legitimate lawmaking actors aligns closely with the growing frustration over the inertia of the MWP. That frustration threatened to erupt on occasion at Bonn. The proposal for a digital mitigation platform, which Brazil and several developing countries endorsed, hints at a transnational infrastructure of practice building. Experimental, often non-binding initiatives of this kind echo the rationalist-constructivist hybridity that Chen locates in initiatives such as C40 and the Western Climate Initiative (WCI). In his article, Chen challenges the focus on state-centric models which typifies the climate-club literature and argues that subnational governments, such as cities and provinces, merit more attention.Footnote 57 Reliance on national governments alone renders climate clubs vulnerable to domestic political turbulence, as evidenced by the United States’ (US) withdrawal from the Kyoto ProtocolFootnote 58 and the Paris Agreement.Footnote 59
Chen demonstrates that subnational climate clubs operate not merely as economic clubs that incentivize compliance through exclusive benefits, but also as communities of practice.Footnote 60 This dual approach draws from both rationalist and constructivist theories of international relations: the former emphasizes cost-benefit calculations and the deterrence of free-riding, while the latter focuses on norm creation, identity building, and mutual expectations.Footnote 61
According to Chen, climate clubs have two principal characteristics: selective membership and benefit generation. Unlike networks or coalitions, which are open and loosely organized, clubs restrict access and impose participation standards.Footnote 62 For instance, WCI members must contribute financially, based on emissions, and commit to cap-and-trade.Footnote 63 C40, in contrast, does not charge membership fees but requires cities to demonstrate climate leadership and to meet performance standards.Footnote 64 Both clubs generate public benefits, such as emissions reductions and policy innovation, and club benefits, such as technical expertise, recognition, and peer support.Footnote 65 Crucially, they contribute to transnational lawmaking by creating legal and normative frameworks that enhance structural stability and foster compliance without relying on sovereign authority.Footnote 66 These clubs form what Brunnée and Toope call ‘interactional law’ – standards of behaviour that are generated through social practices and shared expectations.Footnote 67
Chen asserts that subnational climate clubs should be recognized as valuable institutions within the polycentric climate-governance landscape. By blending rational incentives with constructivist community building, these clubs foster durable, adaptive, and normatively grounded cooperation, thus enhancing the legitimacy, efficacy, and legal capacity of global climate action beyond the constraints of multilateral diplomacy.
3. Climate Ambition and Accountability
The discussions in Bonn on mitigation and adaptation revealed a foundational problem: we do not know how to operationalize climate ambition through tools that are legally robust, context sensitive, and comparable across jurisdictions. In both the GGA and MWP tracks, parties expressed their frustration with the absence of concrete mechanisms for assessing progress and implementation.Footnote 68 In ‘Climate Effects in Environmental Impact Assessment’,Footnote 69 Benoit Mayer proposes climate effect assessment (CEA) – a climate-inflected version of environmental impact assessment (EIA). He offers a methodological bridge between adaptation and mitigation, which can enable climate metrics to be embedded into planning and regulatory cycles. The article contains a comprehensive comparative analysis of the global use of EIA as a tool for climate change mitigation. The CEA that the author proposes integrates climate considerations, primarily on greenhouse gas (GHG) emissions, into EIA procedures.Footnote 70 While EIAs originally targeted local environmental issues, in many regions their scope has expanded to include climate impacts. This shift reflects the growing recognition of CEA as a tool to address GHG emissions from specific projects, such as fossil fuel extraction, transportation infrastructure, and power generation.Footnote 71
CEAs have met with resistance in some jurisdictions. In Kazakhstan and, until recently, in New Zealand, policymakers have argued that CEAs are redundant when cap-and-trade mechanisms are in place.Footnote 72 Critics also argue that emissions from individual projects are too insignificant, which Mayer believes to be a misrepresentation of the cumulative effects of climate change.Footnote 73 He also shows how difficult it is to apply EIAs, which were designed for tangible local effects, to the global and diffuse phenomenon of climate change. Climate effects are abstract, there are no directly affected local communities, and harm can seldom be traced to individual projects.Footnote 74 The author critiques two extreme approaches to determining whether an impact is ‘significant’: namely (i) the inclusionary approach, which casts all emissions as significant as a result of cumulation, and (ii) the exclusionary approach, which deems emissions insignificant unless individually impactful.Footnote 75 Mayer recommends a combination of three more balanced methodologies: (i) quantitative emissions thresholds can be used to trigger CEAs at the screening stage;Footnote 76 (ii) emissions can be assessed by reference to benchmarks such as sectoral norms, regulatory targets, or carbon budgets; and (iii) tools such as the social cost of carbon can quantify climate harm economically.Footnote 77 Mayer emphasizes that no single method can suffice; using a mix, however, would enhance transparency, accountability, and legal certainty. Furthermore, many jurisdictions fail to include in CEAs indirect or downstream emissions, such as emissions from the eventual combustion of extracted fossil fuels.Footnote 78 Lawmakers cite jurisdictional or causal uncertainties as justifications for this approach. Mayer argues that the foreseeability and the causal link between projects and downstream emissions should suffice to warrant their inclusion. On the whole, he develops a compelling argument for the global integration of climate considerations into EIAs. While defining significance and accounting for indirect emissions remain points of difficulty, the article demonstrates how comparative legal analysis can illuminate effective practices. CEAs, as Mayer shows, are not only legally viable but increasingly essential for project-level climate governance. They are both technical instruments and normative tools for realizing the integrative vision of the Paris Agreement.
Accountability depends not only on tools but also on our ability to trace and assign responsibility within complex systems. A tension that recurred in several negotiation tracks at Bonn revolved around responsibility attribution – who pays, who benefits, and who can be held accountable? This tension was evident in the stalemate over Article 9(1) of the Paris Agreement and the fragmented debates about the Adaptation Fund. Efforts to transition the Adaptation Fund to serve exclusively under the Paris Agreement revealed persistent tensions over how adaptation finance should be governed. A compromise was ultimately reached, including reference to indicators measuring access, quality, and provision of adaptation finance – an outcome strongly pushed by developing countries aiming to close the widening adaptation finance gap.Footnote 79 These procedural and technical debates point to the difficulty of operationalizing climate responsibility into law within diffuse systems.
The analysis by Ling Zhu and Xinwei Li, in ‘Identifying Key Polluters: The Feasibility of Applying the Polluter Pays Principle to Marine Greenhouse Gas Emissions’,Footnote 80 offers a valuable lesson to those who are interested in these problems. The authors argue that while the polluter pays principle is normatively appealing and legally embedded in international law, its effectiveness hinges on the identifiability of polluters, which is complicated by the fragmentation of maritime contractual arrangements. The same attribution problem haunts registries and transparency mechanisms in climate finance under Article 6 of the Paris Agreement. If equity and liability are to become meaningful in climate governance, the question of legal accountability in multi-actor transnational systems must be resolved. The focus of Zhu and Li on structural attribution in shipping can thus inform efforts to strengthen accountability frameworks across the UNFCCC process. They argue that current regulatory measures for curbing marine GHG emissions are insufficient and propose the polluter pays principle as the basis of a complementary or alternative framework.Footnote 81 They use the International Maritime Organization (IMO) as an example. Although the IMO has implemented many strategies, such as Annex VI to the International Convention for the Prevention of Pollution from Ships (MARPOL),Footnote 82 the Energy Efficiency Design Index, and the Carbon Intensity Indicator, it has failed to keep pace with the rapidly growing environmental impact of the shipping industry. By 2018, shipping accounted for 1,076 million tonnes of carbon dioxide (CO2) emissions, or around 3% of global emissions.Footnote 83
Technical and operational solutions are inadequate; instead, economic and legal instruments such as the polluter pays principle are necessary. This principle originated from economics and has been incorporated into international legal frameworks over time. It serves four core functions: (i) economic integration, (ii) distribution, (iii) prevention, and (iv) remedial action.Footnote 84 Zhu and Li argue that holding polluters accountable would incentivize cleaner shipping. They conclude that the polluter pays principle is a legally viable and normatively justified means of reducing marine GHG emissions, provided that polluters can be identified clearly. On that argument, it is shipowners, time charterers, and demise charterers who should bear primary responsibility based on their operational roles and their capacity to influence emissions.Footnote 85
4. Trade Governance
The intensifying convergence of climate, trade, and finance was not acknowledged formally at Bonn, while tensions over the European Union’s (EU) carbon border adjustment mechanism (CBAM)Footnote 86 were diffused in advance through pre-sessional diplomacy and its exclusion from the agenda.Footnote 87 However, its influence was evident in the debates about transparency mechanisms for Article 6 of the Paris Agreement and the structuring of the Adaptation Fund. These debates highlighted persistent gaps between legal frameworks and the operational demands of implementation – such as the challenge of designing market mechanisms that ensure environmental integrity while satisfying diverse national interests, or securing predictable adaptation finance amid fragmented institutional mandates.
Sherzod Shadikhodjaev’s work on EIAs in trade agreements offers an instructive parallel. EIAs in trade agreements have matured into tools for embedding ex ante accountability, procedural transparency, and stakeholder engagement into international policymaking.Footnote 88 That same logic now animates disputes about climate finance disclosure, carbon registry standards, and the legitimacy of international offset markets.
That trade EIAs are non-binding but systematic enables them to shape negotiations through what might be called ‘soft conditionality’: the anticipatory assessments influence the design of environmental clauses, side measures, and regulatory safeguards. This logic is mirrored in the push for a more formalized financial reporting structure by developing countries at Bonn and the debates about using mitigation platforms to facilitate implementation, as opposed to focusing exclusively on their accounting functions.
The US, Canada, and the EU have had institutionalized procedures for EIAs of trade agreements for more than two decades. Their experience offers useful models, particularly as trade and environmental concerns become increasingly interdependent.Footnote 89 Canada integrates trade EIAs within its strategic environmental assessment (SEA) framework, whereas the US and the EU use separate procedures.Footnote 90
All three jurisdictions assess the anticipated environmental impacts of trade liberalization qualitatively and through economic modelling. The broader approach of the EU includes effects on partner and third countries and covers environmental, social, and human rights dimensions. The US and Canada focus on domestic environmental concerns.Footnote 91 Notably, none of the assessments that Shadikhodjaev reviews found that serious environmental harm would result from a trade agreement, largely as a result of low pre-existing tariffs and stable production patterns.Footnote 92
Shadikhodjaev concludes that, as environmental concerns grow, trade EIAs should become routine and systematic.Footnote 93 The author’s work on trade EIAs also underscores a shift in legal expectations. Just like the procedural frictions at Bonn revealed growing demand for transparency, accountability, and enforceability, so too does the push for mainstreaming environmental scrutiny into trade frameworks reflect the emergence of a norm of environmental due diligence across policy domains.
As multilateralism appears to stall, states are turning increasingly to flexilateralism. Trade was not the centrepiece at Bonn, but it cast a long shadow over proceedings. In ‘Flexilateralism in EU Trade Policy: The Case of Aviation Fuels in the Hardening Environmental Trade Instruments’,Footnote 94 Harri Kalimo, Simon Happersberger and Eleanor Mateo’s treatment of flexilateralism captures the new strategic posture of the EU, which blends multilateral engagement with unilateral regulatory assertiveness. The ReFuelEU policyFootnote 95 and the EU’s CBAMFootnote 96 shift the centre of gravity from consensus building to regulatory leverage. That such strategies are viewed increasingly as pragmatic rather than adversarial is evidence of a transformation in environmental diplomacy. Kalimo, Happersberger and Mateo examine a significant shift in EU trade policy. The new strategy is flexible and assertive, and it draws on both bilateral and unilateral instruments. The authors introduce the concept of ‘flexilateralism’ to describe this pragmatic policy mix, especially in the context of environmental sustainability. Sustainable aviation fuels serve as a key case study.
The principal conceptual contribution of the article lies in the introduction of the term ‘flexilateralism’, which captures the use of multilateral, bilateral, and unilateral instruments in combination instead of privileging one form of engagement over another. This shift reflects a growing recognition that environmental goals may not be achievable through multilateralism alone, especially in the face of stalled World Trade Organization (WTO) negotiations.Footnote 97 The authors compare the hardness (legal binding effect and enforceability) and ambition (level of environmental standard setting) of EU instruments across three arrangements: (i) the International Civil Aviation Organization (ICAO) Carbon Offsetting Reduction Scheme for International Aviation (CORSIA)Footnote 98 as an example of multilateralism; (ii) the EU–IndonesiaFootnote 99 and EU–MercosurFootnote 100 Preferential Trade Agreements as examples of bilateralism, and (iii) the ReFuelEU RegulationFootnote 101 as an example of unilateralism. They argue that these instruments are not substitutes but parts of a flexible policy architecture. The EU continues to engage in multilateral and bilateral fora but complements them with stronger unilateral tools. Rather than being ideologically committed to multilateralism, the EU now appears increasingly pragmatic.Footnote 102
Flexilateralism could be a new dawn in EU trade governance. This evolution may also include greater involvement of non-state actors, potentially expanding into what the authors call ‘polylateralism’, that is, cooperation between states and private or civil society actors.Footnote 103
5. Conclusion: Lawmaking in the Anthropocene
Taken together, the scholarly contributions and the outcomes from the Bonn 2025 SB-62 signal the maturation of climate law into a polycentric, multilevel, and often contradictory ecosystem. They also showcase its adaptability. Law is no longer confined to treaties, nor justice to the outcomes of formal negotiations. Legal norms now percolate through judicial reasoning, subnational leadership, Indigenous advocacy, clinical pedagogy, and administrative experimentation.
As COP-30 in Belém approaches, the unresolved tensions around adaptation metrics, mitigation ambition, carbon markets, and finance will demand not only political compromise, but also juridical inventiveness. What Bonn demonstrated, often through contestation rather than consensus, is that legal pluralism is not a pathology of climate law – it is the legal grammar that we need in the Anthropocene.
6. TEL Editorial Board Announcements
It is with great pleasure and gratitude that we share the news of TEL’s latest Impact Factor. In the 2024 Clarivate Journal Citation Reports (JCR), TEL’s two-year Impact Factor increased to 3.3 (5-yr Impact Factor 3.6). This confirms TEL’s position among the highest-ranking environmental law journals, as well as ranking 8th out of all 434 law journals featured in the 2024 JRC. Paired with continued increases in key usage metrics and other citation index rankings, these results speak volumes to the vibrant scholarly TEL community. As always, we are grateful for the efforts of the entire TEL team, and above all for our contributing authors, reviewers, and readers, who are a pre-condition to TEL’s continued success.
