3.1. Evidentiary Framework on Climate Change

Before addressing the substance of the claims, the Court set out a comprehensive evidentiary framework on climate change and underscored the necessity of integrating the analysis of procedural and substantive matters. As regards the scientific standards, two points warrant particular emphasis. Firstly, drawing primarily on the IPCC Sixth Assessment Report, the Court acknowledged that the rise in greenhouse gas (GHG) concentrations since 1750 is ‘unequivocally’ anthropogenic, and that cumulative emissions have led to more frequent and intense heatwaves attributable to human influence on the climate system.Footnote ¹³

Secondly, the Court found that rising temperatures were already contributing to increased mortality and serious health risks, disproportionately affecting older adults, women, and infants. In this sense, it endorsed the scientific consensus that many heat-related deaths and impairments could be avoided by respecting the 1.5°C ceiling set under the Paris Agreement.Footnote ¹⁴ With specific regard to Switzerland, the judges relied on data from the Federal Office of Meteorology and Climatology, which recorded a 2.1°C increase in mean annual temperatures since 1864 and drew attention to anomalously hot summers as having caused significant excess mortality, particularly among those aged over 75.Footnote ¹⁵ Notably, the judgment also explicitly referenced and evaluated individual scientific studies and expert evidence submitted as part of the case record, which provided supplementary case-specific material relating to the impact of climate change on elderly women.

3.2. Joinder of Procedural and Substantive Matters

By the time of the judgment in KlimaSeniorinnen, the Court had already dismissed three climate-related applications under Articles 2 and 8 ECHR, finding in each instance that the applicants were ‘not sufficiently affected’ to claim victim status ‘within the meaning of Article 34’.Footnote ¹⁶ On the same day, it also delivered its decisions in Carême v. France Footnote ¹⁷ and Duarte Agostinho v. Portugal,Footnote ¹⁸ which can broadly be read as forming a line of jurisprudence alongside KlimaSeniorinnen. As noted by Heri, among others, this first wave of climate litigation was widely anticipated to have the potential to shape the Court’s approach to the impact of climate change on, inter alia, individual rights, extraterritoriality, and standing requirements.Footnote ¹⁹

In KlimaSeniorinnen, the Grand Chamber expressly merged its analysis of procedural and substantive issues, holding that victim status could not be assessed in isolation from the question of whether the state bore protective obligations in the context of climate mitigation.Footnote ²⁰ On closer examination, this approach reflects the Hirsi Jamaa and Others v. Italy rationale that standing and merits must be considered together when closely intertwined – an expression of the Court’s broader commitment to interpretative coherence, according to which the Convention ‘must be read as a whole’ so as to ensure ‘harmony between its various provisions’.Footnote ²¹ It similarly mirrors the underlying tenets of the ECtHR’s environmental jurisprudence whereby the assessment of victim status remains intrinsically linked to the scope of the state’s margin of appreciation and due diligence obligations.Footnote ²² Accordingly, the victim status test (set out in paragraphs 487 and 488 of the judgment) hinges on standards of ‘high intensity of exposure’ and a ‘pressing need to ensure the applicant’s individual protection’, which themselves are relative to the modulation of the margin of appreciation and to the context-specific applicability of Articles 2 and 8.

3.3. Protective Duties under Article 8

After ruling on the admissibility of the case, the Court turned to the substantive question of what states are required to do under the Convention to protect individuals from the effects of climate change. It addressed this exclusively within the scope of Article 8, glossing over Article 2 because of the ‘more questionable’ prospects of its applicability and the partial doctrinal overlap with Article 8 in environmental cases.Footnote ²³ In this respect, a central outcome of the judgment is the interpretative expansion of Article 8 to include ‘a right for individuals to effective protection by the state authorities from serious adverse effects of climate change on their life, health, well-being and quality of life’.Footnote ²⁴ This understanding is shaped by both the systemic integration of international scientific and legal standards as per the 1969 Vienna Convention on the Law of Treaties (VCLT),Footnote ²⁵ and the Court’s own living instrument doctrine. The two, in fact, operate in close coordination, as the latter requires that the Convention be ‘interpreted in the light of present-day conditions, and in accordance with developments in international law, so as to reflect the increasingly high standard being required in the area of the protection of human rights’.Footnote ²⁶

The Court articulated a two-tiered margin of appreciation, reflecting a critical disaggregation of the political questions embedded in climate mitigation. It found that states are legally bound by their ‘commitment to the necessity of combating climate change and its adverse effects’, an outcome warranted by the ‘nature and gravity of the threat’, the ‘general consensus as to the stakes involved’, and their internationally ‘accepted commitments to achieve carbon neutrality’.Footnote ²⁷ As a consequence, Article 8 requires that ‘each Contracting state undertake measures for the substantial and progressive reduction of their respective GHG emission levels, with a view to reaching net neutrality within, in principle, the next three decades’. In relation to science-based, quantitative targets, the case for legal accountability is therefore particularly pronounced, and the states’ margin of appreciation correspondingly ‘reduced’.Footnote ²⁸ Conversely, states retain broad discretion in the selection of means.

The discharge of such obligations is governed by due diligence requirements, as emphasized by the Court, consistent both with its existing case law on environmental harm and with the broader orientation of due diligence in international environmental law.Footnote ²⁹ In the first sense, the Court has consistently affirmed that states must establish and effectively implement legal frameworks capable of protecting individuals from environmental risks to their health and well-being.Footnote ³⁰ These obligations are compounded by procedural guarantees, including access to information, public participation, and oversight of decision-making processes.Footnote ³¹ In line with these benchmarks, the Court in KlimaSeniorinnen held that in climate cases it will assess whether domestic authorities – legislative, executive, or judicial – have duly considered the need to:

In a broader sense, the due diligence standards read into Article 8 closely reflect foundational principles of international environmental law.Footnote ³³ For instance, in Pulp Mills on the River Uruguay (Argentina v. Uruguay),Footnote ³⁴ the International Court of Justice (ICJ) affirmed that the obligation to protect the aquatic environment entails a duty of due diligence, requiring states to adopt appropriate legislative and regulatory measures, and to maintain a degree of vigilance in their enforcement.Footnote ³⁵ More recently, in its July 2025 advisory opinion on the Obligations of States in respect of Climate Change,Footnote ³⁶ the ICJ explicitly extended this duty to the climate system, echoing the 2024 advisory opinion of the International Tribunal for the Law of the Sea (ITLOS).Footnote ³⁷ The ICJ emphasized that ‘the duty to prevent significant harm to the environment also applies to the climate system, which is an integral and vitally important part of the environment and which must be protected for present and future generations’.Footnote ³⁸ It similarly acknowledged the wide-ranging implications of climate change for the enjoyment of human rights.Footnote ³⁹ Just weeks earlier, the Inter-American Court of Human Rights (IACtHR), in its own Advisory Opinion OC-32/25 on Climate Emergency and Human Rights, had elaborated in detail on the heightened due diligence obligations incumbent upon states under international environmental law, finding that the climate crisis requires states to exercise an ‘enhanced’ standard of care in preventing rights violations.Footnote ⁴⁰

From the standpoint of international environmental law, the approach of the ECtHR reflects a deliberate openness to the deepening intersections between human rights protection, environmental due diligence, and climate governance.Footnote ⁴¹ In so doing, Strasbourg not only anticipated but also helped to steer converging developments across international legal regimes.Footnote ⁴²

3.4. Margin of Appreciation

Applying the above framework, the Court found that Switzerland had violated Article 8 by failing to establish and effectively implement a regulatory framework capable of ensuring the timely and substantial reduction of GHG emissions. The Court identified several shortcomings in its analysis. Firstly, although the 2011 Federal Act on the Reduction of CO₂ Emissions (CO₂ Act)Footnote ⁴³ had envisaged a 20% reduction by 2020, Switzerland achieved only an 11% reduction. Secondly, while the subsequent 2022 Climate Act introduced interim milestones for the periods 2021 to 2024 and 2031 to 2040, it provided no binding regulatory framework for the intervening years 2025 to 2030 – a deficiency that the Court deemed ‘incompatible with the requirement of the existence of general measures specifying the respondent state’s mitigation measures in line with a net neutrality timeline’. A previous initiative, launched in December 2017 by the Federal Council – the state executive – to revise the CO₂ Act to target a 30% reduction by 2030 had been rejected in a popular referendum. Thirdly, the Climate Act deferred key measures, including the determination of national carbon budgets, to future legislative and executive action to be taken ‘in good time’, which Switzerland was yet to adopt, and the Court deemed structural to the due diligence expected of the Member State.Footnote ⁴⁴

Overall, by failing to adopt a clear carbon budget in a timely manner and to set intermediate reduction pathways for the period 2025 to 2030, the Court found Switzerland to have exceeded the margin of appreciation afforded to states in defining climate objectives. Importantly, while the judges did not dispute Switzerland’s discretion in selecting the specific measures functional for combating climate change, it made clear that such discretion is constrained by the overarching obligation to take timely and effective action.

4.1. Victim Status under Article 34

In pursuit of the first aim, the Court reads the effectiveness requirement in line with its mandate for evolutive interpretation, holding in this sense that ‘a failure … to maintain a dynamic and evolutive approach would risk rendering it a bar to reform or improvement’.Footnote ⁴⁶ Accordingly, the term ‘victim’ in Article 34 must ‘be interpreted in an evolutive manner in the light of conditions in contemporary society’, since a static or excessively formalistic interpretation would risk rendering rights ‘ineffectual and illusory’ and undermining the judiciary’s task to ‘ensure the necessary oversight of compliance with legal requirements’.Footnote ⁴⁷ At the same time, the Court must carefully ponder the case for judicial intervention and legal accountability within the contours of its own judicial role under the ECHR, the violation-based and individual justice rationales of which are safeguarded by the prohibition of actio popularis.Footnote ⁴⁸ If, as the Court warned in Carême, the ‘circle of victims … is drawn in a wide-ranging and generous manner’, judicial recourse risks becoming ‘a means of prompting changes in general policies regarding climate change’, thereby circumventing the exclusion of general interest claims and diluting the Convention’s protective capacity.Footnote ⁴⁹ Conversely, if ‘this circle is drawn too tightly and restrictively … even obvious deficiencies or dysfunctions in government action or democratic processes’ may leave individuals without ‘any judicial recourse before the Court’.Footnote ⁵⁰

In the Court’s view, the need for effectiveness is further reinforced by the unique factual dynamics of climate change mitigation, in which ‘the members of society who stand to be most affected by the impact’ often find themselves at a distinct representational disadvantage. In this light, the Court appears to gesture towards a representation-reinforcement rationale, a notoriously established theme in comparative constitutional theory,Footnote ⁵¹ the transposition of which into the ECHR framework is not without complexity, given the Convention’s distinctly negative connotation of democracy and the political process, understood primarily as benchmarks for permissible restrictions on rights rather than as vehicles for their expansion.Footnote ⁵² Notably, in fact, the Court brought the principle of intergenerational burden-sharing, which it found to be a legal requirement under Article 3 UNFCCC,Footnote ⁵³ into the justificatory precinct for the applicant association’s locus standi. As will be shown, and contrary to the views advanced by some commentators that the Court effectively accepted actio popularis in substance,Footnote ⁵⁴ this amounts to an indirect, or ‘surrogate’, protection of future generations.

The Court found Article 34 to require an applicant ‘to show that he or she was personally and directly affected’ in relation to claims ‘concerning harm or risk of harm resulting from alleged failures by the state to combat climate change’.Footnote ⁵⁵ To this end, two essential criteria are drawn in the judgment: (i) the applicant must demonstrate subjection ‘to a high intensity of exposure to the adverse effects of climate change, that is, the level and severity of (the risk of) adverse consequences of governmental action or inaction affecting the applicant must be significant’; and (ii) there must exist ‘a pressing need to ensure the applicant’s individual protection, owing to the absence or inadequacy of any reasonable measures to reduce harm’. As the Court explains, these criteria are closely linked to the applicability of the substantive provisions invoked, and the threshold for satisfying them ‘is especially high’, requiring an assessment of all relevant circumstances, including ‘individual specificities and vulnerabilities’. Factors that the Court will consider include the nature and scope of the Convention complaint; the actuality, remoteness, and/or probability of the adverse effects of climate change; the specific impact on the applicant’s life, health, or well-being; the magnitude and duration of the harmful effects; the geographical scope of the risk (whether localized or general); and the applicant’s particular vulnerability.Footnote ⁵⁶

4.2. Applicability of Articles 2 and 8

In its separate applicability analysis, the Court found that, with respect to Article 2, climate change-related obligations align with its existing environmental case law on activities that, by their very nature, are capable of endangering life.Footnote ⁵⁷ This finding was based both on the general contribution of climate change to ‘heat-related human mortality’ and on the heightened vulnerability of populations at ‘highest risk’ – particularly older adults, children, and women – as evidenced by the 2018 IPCC Special Report.Footnote ⁵⁸ Accordingly, the applicability of Article 2 depends on the ascertainment of a ‘real and imminent’ risk to life arising from ‘State action and/or inaction’, construed as ‘a serious, genuine and sufficiently ascertainable threat to life’, where ‘imminence’ encompasses both physical and temporal proximity ‘to the harm complained of’.Footnote ⁵⁹

As anticipated in Section 3, the Court declined to assess the applicability of Article 2 in KlimaSeniorinnen, noting that the existence of life-threatening conditions in the case was ‘more questionable’ than interferences with private life, and that its analysis under Article 8 rendered a separate consideration unnecessary. The applicability of Article 8, in fact, centres on the comparatively more flexible threshold of an ‘actual interference with the applicant’s enjoyment of his or her private or family life or home’,Footnote ⁶⁰ where the general deterioration of the environment is not sufficient on its own.Footnote ⁶¹ In the specific climate context, the assessment of minimum severity requires consideration of ‘all the circumstances of the case, such as the intensity and duration of the nuisance and its physical or mental impact on the applicant’s health or quality of life’,Footnote ⁶² and the alleged harm must not be negligible ‘in comparison to the environmental hazards inherent in life in every modern city’.Footnote ⁶³ Article 8 may also be engaged by exposure to a ‘serious environmental risk’, provided that this risk bears a sufficiently close connection to the applicant’s private or family life.

Importantly, the assessment is not confined to demonstrable health impairments, as a serious interference may also arise where the applicant is prevented from enjoying the amenities of their home.Footnote ⁶⁴ This substantive nuance in the applicability of Article 8 held only theoretical significance in KlimaSeniorinnen, as all applicants advanced health-related claims. It could have acquired practical significance in Carême, where the applicant alleged impacts on their private life and living conditions resulting from increased risks of coastal erosion and flooding in the municipality of Grande-Synthe, had the case not turned moot as a result of Mr Carême’s relocation to Brussels.

4.3. Sufficient Severity and Reasonable Inevitability

On the Court’s own admission, the standards of ‘actual interference’ under Article 8 and of a ‘real and imminent threat to life’ under Article 2 remain closely tied to the victimhood test set out in paragraphs 487 and 488 of the judgment. This correlation was also evident in Carême, in which claims of direct and personal exposure to heightened risks of coastal erosion, floods, and inundation were to be assessed through the joint lens of victim status and the applicability thresholds of Articles 2 and 8.Footnote ⁶⁵ Such a high level of integration illustrates how the applicability of substantive Convention provisions in the climate context remains mediated by circumstantial trade-offs between judicial restraint and legal accountability, as reflected in the ‘especially high’ victim status thresholds of ‘high intensity of exposure’ and ‘pressing need to ensure individual protection’. For potential victimhood, the assessment becomes even more exacting, given its general confinement to ‘highly exceptional circumstances’.

Applying this interpretative framework, the Court dismissed the individual complaints brought by applicants numbered 2 to 5 under Article 8 ECHR, finding that the ‘especially high’ threshold for victim status required each applicant to demonstrate that the ‘particular level and severity of the adverse consequences’ had been met, including individual vulnerability giving rise to ‘a pressing need to ensure their individual protection’.Footnote ⁶⁶ A distinction may be drawn among the four individual applicants. Applicants numbered 2 to 4 submitted personal accounts detailing medical difficulties experienced during heatwaves and the adaptive strategies adopted in response. The Court cross-examined these submissions with scientific evidence, including IPCC and United Nations (UN) reports, acknowledging that the applicants belonged to a group ‘particularly susceptible to the effects of climate change’. Nonetheless, it concluded that they did not suffer ‘from any critical medical condition whose possible aggravation linked to heatwaves could not be alleviated by the adaptation measures adopted in Switzerland or by means of reasonable measures of personal adaptation’.Footnote ⁶⁷ Their exposure – whether actual or prospective – thus failed to reach the requisite ‘degree of intensity giving rise to a pressing need to ensure their individual protection’.Footnote ⁶⁸ This reasoning may plausibly be read as rejecting only the second limb of the Article 34 victim status test – namely, the absence of a ‘pressing need’ for individual protection in the light of the perceived adequacy of available adaptation measures – while implicitly accepting the plausibility of their exposure. By contrast, the claim of applicant 5 was rejected more straightforwardly, as it rested on a generalized statement ‘not indicating any particular morbidity or other serious adverse effects that would go beyond the usual effects which any person belonging to the group of older women might experience’. On this basis, the Court found no substantive link between her individual condition and the application, thereby failing both limbs of the Article 34 test.Footnote ⁶⁹

Overall, the Court’s scrutiny of health-based complaints under Article 8 proceeded from the non-justiciability of general environmental degradation to require (i) concrete evidence of particularly serious health impacts; and (ii) the absence of reasonable adaptation measures – whether regulatory or personal – to prevent present or future harm. This second condition may be understood as demanding the reasonable inevitability of harm, benchmarked against standards of legislative, administrative, and personal due diligence which, in turn, reflect the Court’s standardization of effective climate protection as encompassing ‘adaptation measures aimed at alleviating the most severe or imminent consequences of climate change, taking into account any relevant particular need for protection’.Footnote ⁷⁰ While, in relation to applicants numbered 2 to 4, some authors have construed the readily available adaptation measures as coextensive with ‘access to healthcare’,Footnote ⁷¹ the precise contours of the reasonable inevitability requirement remain unsettled, as do the boundaries of state obligations in the area of adaptation measures. At present, a breach of regulatory reasonableness is likely to require either overt legislative inertia or executive bad faith in the face of foreseeable and severe harm to vulnerable populations – circumstances that would surely encompass retrogressive political action, such as legal departures from the Paris Agreement,Footnote ⁷² the UNFCCC,Footnote ⁷³ or the Aarhus Convention.Footnote ⁷⁴ For now, however, the Court’s reasonableness standard should shield states in the exercise of policy discretion, so long as their ‘commitment to the necessity of combating climate change and its adverse effects’ remains credible and demonstrable. Personal adaptation, by contrast, raises complex questions of proportionality, financial burden, and acceptable limitations on fundamental rights. It remains to be seen what degree of cost or inconvenience to individual rights may be tolerated in the face of changing climatic conditions.

As for the second limb of the victim status test, it seems reasonable to suggest that for health-based claims under Article 8 conditions may need to deteriorate further before the balance between legal accountability and judicial restraint tips in favour of individual victimhood. For the moment, the pathway to establishing victim status remains exceptionally narrow and may be confined to rare, ‘highly individualised’Footnote ⁷⁵ cases where specific medical and personal circumstances combine to engage the state’s duty to protect against ‘the most severe or imminent consequences of climate change’.Footnote ⁷⁶ In this light, non-health-related claims under Article 8 – such as those advanced in Carême – may prove more viable in the short to medium term. In such cases, the inevitability of projected harm, the impossibility of personal mitigation (as in the face of sea-level rise), and the absence of specific regulatory guardrails could together offer stronger grounds for establishing individual victim status.

5.1. Special Considerations for Legal Representation

By settled case law, NGOs and non-governmental associations face significant hurdles in claiming victim status under Articles 2 and 8 of the Convention, owing to the prohibition of public interest claims and the inherently personal nature of these rights.Footnote ⁷⁸ In KlimaSeniorinnen, this standard was reaffirmed, with the Court reiterating that associations ‘cannot rely on health considerations or nuisances and problems associated with climate change which can only be encountered by natural persons’.Footnote ⁷⁹ Nevertheless, associations may obtain access to judicial review even when they are not themselves the direct victims of a violation, provided they demonstrate the existence of ‘special considerations’ justifying the representation of individual victims. This opening has enabled the ECtHR to extend standing to associations even where they held no power of attorney or where the individual victims could, in principle, have brought a complaint themselves.Footnote ⁸⁰

The rationale for this jurisprudential flexibility has traditionally been twofold. Firstly, it reflects a principled concern to ensure that serious allegations of Convention breaches do not escape judicial scrutiny or state accountability.Footnote ⁸¹ In this light, the relaxation of locus standi, for which environmental litigation offers a paradigmatic example, serves the dual aim of safeguarding the effectiveness of Convention rights and affording heightened protection to particularly vulnerable groups. In Valentin Câmpeanu,Footnote ⁸² the Court underscored that serious claims must be heard on the merits, cautioning that shielding Member States from accountability ‘would not be consistent with the general spirit of the Convention, nor with the High Contracting Parties’ obligation under Article 34 of the Convention not to hinder in any way the effective exercise of the right to bring an application before the Court’.Footnote ⁸³ These concerns similarly informed the Court’s examination of the ‘specific considerations relating to climate change’ in KlimaSeniorinnen.

Secondly, and more broadly, the Court has viewed applications brought by associations as opportunities to develop coherent interpretative frameworks in contexts marked by the presence of structurally vulnerable groups. It has consistently stressed that its judgments serve ‘not only to decide those cases brought before [it] but, more generally, to elucidate safeguards and develop the rules instituted by the Convention, thereby contributing to the observance by the states of the engagements undertaken by them as Contracting Parties’.Footnote ⁸⁴ Against this backdrop, the Court’s recognition of the applicant association’s locus standi in KlimaSeniorinnen rested on three interrelated factual considerations: (i) the unique characteristics of climate change, including its diffuse, cumulative, and transboundary nature; (ii) its status as a ‘common concern of humankind’, demanding ‘intergenerational burden-sharing’ and reflecting the ‘urgency of combating the adverse effects of climate change and the severity of its consequences, including the grave risk of their irreversibility’; and (iii) the growing role of civil society organizations in climate litigation, where collective representation may constitute ‘one of the only means through which the voice of those at a distinct representation disadvantage can be heard’.Footnote ⁸⁵ Taken together, these considerations justified the Court’s evolutive approach to locus standi in KlimaSeniorinnen, with the aim of safeguarding the practical effectiveness of Convention rights and affirming an autonomous role in climate litigation.

5.2. Climate Mitigation and the Interested Public

As noted by Keller and Gurash,Footnote ⁸⁶ since Gorraiz Lizarraga v. Spain Footnote ⁸⁷ the ECtHR has exhibited a degree of benevolence towards NGOs, particularly where it would be manifestly unreasonable to expect individual victims to pursue litigation. This flexibility, however, remained conditional on the organization demonstrating why the affected individuals were unable to initiate proceedings themselves.Footnote ⁸⁸ The KlimaSeniorinnen judgment marks a subtle yet significant departure from this logic of representational necessity, as the Court granted locus standi to the applicant association without confirming ‘victim status for any specific individual on whose behalf the application [was] brought’.Footnote ⁸⁹ Unlike in Valentin Câmpeanu, where the applicant’s inability to litigate was factual and rooted in physical incapacity, the Court in KlimaSeniorinnen explicitly decoupled locus standi from the requirement that represented individuals satisfy the Article 34 victim status criteria.Footnote ⁹⁰ In this sense, the impracticability of pursuing individual litigation was construed in legal rather than factual terms, grounded in the disambiguation between the requisite ‘high intensity of exposure to the adverse effects of climate change’ and the existence of ‘a pressing need to ensure the applicant’s individual protection’. The absence of such a ‘pressing need’ was therefore waived in the light of the association’s members verified ‘exposure to the adverse effects of climate change’, given the above-mentioned ‘special considerations’.

This jurisprudential shift was justified by the Court through extensive reliance on systemic integration under Article 31(3)(c) VCLT,Footnote ⁹¹ with particular emphasis on international environmental law and the Aarhus Convention. Article 9(3) of the Aarhus Convention requires states to ensure broad access to justice for ‘members of the public’ in environmental matters, while Article 2(5) expressly includes NGOs pursuing environmental protection as part of ‘the public concerned’, provided they meet domestic legal requirements.Footnote ⁹² The ECtHR interpreted the treaty as requiring that standing be the rule rather than the exception, even in climate litigation. To reinforce the argument that the Aarhus Convention supported a ‘legal’ rather than a purely factual construction of the impracticality of individual litigation, the Court relied on a broad comparative survey of constitutional standards on access to justice for NGOs and environmental associations across Member States of the Council of Europe. It noted the ‘nearly universal ratification of the Aarhus Convention’ and observed that, in the majority of jurisdictions, at least ‘a theoretical possibility’ existed ‘for environmental associations to bring a climate-change case’, with several states already recognizing such standing either by statute or judicial practice.Footnote ⁹³

Drawing from the Aarhus framework and comparative state practice, the Court ultimately articulated three fundamental criteria for the standing of associations in climate cases: (i) lawful establishment within the relevant jurisdiction, with the relevant qualification that compliance with domestic requirements cannot grant states unfettered discretion in defining access to justice standards, but must instead be assessed in the light of the essential role of associations in climate justice;Footnote ⁹⁴ (ii) demonstrable statutory dedication to the ‘defence of the human rights of its members or other affected individuals within the jurisdiction concerned … against the threats arising from climate change’; and (iii) qualified representation, meaning the ability to ‘demonstrate that it can be regarded as genuinely qualified … to act on behalf of members or other affected individuals within the jurisdiction who are subject to specific threats or adverse effects of climate change on their lives, health or well-being’.Footnote ⁹⁵ This assessment is inherently context-specific and must take account of the factors listed by the Court (at paragraph 502), which include ‘the purpose for which the association was established, that it is of non-profit character, the nature and extent of its activities within the relevant jurisdiction, its membership and representativeness, its principles and transparency of governance’.

6.1. Paradox 1: Associational Representation without Designated Individual Victims

As explained, the Court’s test for locus standi draws heavily on the Aarhus Convention, invoking explicitly the principle of systemic integration, the near-universal ratification of the Aarhus Convention among Member States of the Council of Europe, the comparative convergence on standing for environmental organizations in climate litigation, and the ECtHR’s own prior engagement with the instrument. Together, these considerations underpinned the Court’s chief innovation: that locus standi review ‘will not be subject to a separate requirement of showing that those on whose behalf the case has been brought would themselves have met the victim status requirements for individuals … as established in paragraphs 487 to 488’.

This raises an initial critical question concerning the extent of the purported consonance between the Aarhus Convention and the ECHR – an alignment that is far from straightforward. On the one hand, as Keller and Gurash have noted, prior to KlimaSeniorinnen the ECtHR’s engagement with the Aarhus Convention had been limited to procedural matters largely coextensive with access to information and participation in decision-making as civil rights of legal representatives under Article 6 ECHR.Footnote ⁹⁸ In this respect, the Court had relied on the Aarhus framework to upgrade, at a generally lower level of procedural rigour,Footnote ⁹⁹ the ECHR’s own guarantees, without extending its reach into substantive environmental protection.Footnote ¹⁰⁰ On the other hand, significant normative divergences between the two instruments remain, which the Court itself acknowledged by cautioning against (i) the ‘difference between the basic nature and purpose’ of the ECHR and the Aarhus Convention, and (ii) the conceptual and factual distinctions between climate change and the ‘more linear and localized (traditional) environmental issues which the Aarhus Convention is designed to address’.Footnote ¹⁰¹ Pursuant to the latter point, the Court emphasized that the broad standing granted to the ‘interested public’ under the Aarhus Convention – reflecting its concern with the protection of the environment as ‘public good’Footnote ¹⁰² – cannot, within the ECHR’s focus on individual justice, justify engagement in factually abstract review of domestic policy. As will be seen below, these divergences between climate and environmental litigation proved to be decisive in the Court’s subsequent denial of locus standi to the applicant associations in Cannavacciuolo v. Italy,Footnote ¹⁰³ a case concerning large-scale environmental pollution in the Terra dei Fuochi.

It should be clear at this point that the ECtHR in KlimaSeniorinnen deliberately glossed over certain technical differences between the ECHR and the Aarhus Convention in order to embrace the latter’s broad mandate to ‘ensure that non-governmental organizations have wide access to justice’ in environmental matters, as provided under Article 9(3).Footnote ¹⁰⁴ As Pedersen observed, the Court’s test for legal representation may thus be read ‘as the Aarhus Convention with an ECHR twist’ – a hybrid formulation that, paradoxically, appears even more permissive than the Aarhus Convention itself.Footnote ¹⁰⁵ This doctrinal fusion enabled the Court to depart from the more restrictive standards articulated in Valentin Câmpeanu and reaffirmed in Yusufeli, allowing it, in climate cases, to dispense with the requirement that organizations demonstrate either the individual victim status or the factual impediment to litigation of those they represent. As anticipated, the context-specific nature of this approach is confirmed by Cannavacciuolo, in which the Court reinstated both the individual designation and factual impediment requirements for environmental litigation.Footnote ¹⁰⁶ In doing so, it underscored the exceptional link between the more flexible locus standi doctrine in KlimaSeniorinnen and what it had described as ‘specific considerations relating to climate change’, including ‘the special feature of climate change as a common concern for humankind’.

Contrary, therefore, to Judge Eicke’s separate opinion – which held that the Court had granted standing ‘independently of whether their members are victims or not’ – the judgment is better read as waiving the individual designation and factual impediment requirements in recognition of two interrelated practical realities: (i) the near unattainability of health-based individual victimhood in climate litigation; and (ii) the structural necessity of organizational representation as ‘one of the only means through which the voice of those at a distinct representation disadvantage can be heard and through which they can seek to influence the relevant decision-making processes’.Footnote ¹⁰⁷ In this respect, KlimaSeniorinnen retains a degree of continuity with the ECtHR’s previous locus standi jurisprudence in environmental cases, particularly its insistence that individual litigation would be manifestly unreasonable. Yet, in the climate context – and consistent with the Court’s expanded reliance on the Aarhus framework – that requirement is transformed from a factual to a legal construct, reflecting the ‘exceptionally high threshold’ for individual victim status.Footnote ¹⁰⁸

As Heri succinctly notes, organizational standing may ‘simply be possible at a lower (regular) threshold of victim status than individual climate applications’.Footnote ¹⁰⁹ This interpretative turn was instrumental in enhancing the practical effectiveness of ECHR rights in the context of climate change, consonant with the principle of evolutive interpretation requiring the Convention to respond meaningfully to the human rights implications of climate harm.Footnote ¹¹⁰ Caught, as Winter describes, within ‘the multidimensional tension between the braking principle and the liberating principle’,Footnote ¹¹¹ the Court ultimately turned to the Aarhus Convention to expand the standing of NGOs beyond mere procedural guarantees and to assert the virtues of legal accountability under the ECHR in the evolving landscape of climate litigation.

6.2. Paradox 2: Intergenerational Burden-Sharing without Abstract Review

On another front, the ECtHR’s first engagement with ‘special considerations’ justifying legal representation in climate litigation raises a difficult question that lies at the core of preserving both the prohibition of actio popularis and the anchoring of the Court’s role within an individual-justice framework.Footnote ¹¹² This concerns the interpretative function that should be ascribed to intergenerational burden-sharing within such ‘special considerations’, later reiterated in Cannavacciuolo, in which the Court recalled the connection between the KlimaSeniorinnen standards on locus standi and the ‘necessity of promoting intergenerational burden-sharing’.Footnote ¹¹³

As Nolan observed, the Court’s emphasis on this notion in KlimaSeniorinnen is particularly pronounced.Footnote ¹¹⁴ It arguably reflects a representation-reinforcing rationale, suggesting that the Court bears a special responsibility to address legislative bias and the structural neglect of future generations as a vulnerable group. For Letsas, this emphasis – combined with various interpretative flexibilities in the Court’s case law – supports the formal construction of future generations as potential victims within the ECtHR’s reasoning. On that view, the association could be seen ‘as having brought a claim not in the public interest, or on behalf of its members, but on behalf of victims (future generations) who are unable to do so’.Footnote ¹¹⁵

Several considerations, however, weigh against this interpretation. Firstly, Verein KlimaSeniorinnen Schweiz did not rely on intergenerational arguments in its initial application, grounding its claims in present and empirically verified impacts on its members. References to future generations appeared only marginally in supplementary submissions.Footnote ¹¹⁶ Under Letsas’ reading, the Court would therefore have had to manipulate the association’s legal claims to recharacterize them as intergenerational. Secondly, the Court anchored its reasoning in the association’s statutory mandate to ‘promote and implement effective climate protection on behalf of its members’, enabling it to conclude that the association acted not in the general interest but in pursuit of objectives directly connected to its members’ experiences. Thirdly, the locus standi test itself distinguished the relevant interest requirement: associations must show a statutory commitment to defending ‘the human rights of its members or other affected individuals within the jurisdiction concerned’,Footnote ¹¹⁷ where ‘other affected individuals’ must still be exposed to ‘specific threats or adverse effects of climate change’. The Court never discussed this in relation to future generations.

In short, the association’s standing did not arise from general-interest concerns or from direct representation of future generations, but from the actual harm suffered by the elderly women represented, whose vulnerability to heatwaves the Court accepted as factually established. Those same impacts were assessed differently for locus standi and individual victimhood: failure to reach the ‘especially high threshold’ for the latter does not mean ‘they – or other members of the association – were unaffected’.Footnote ¹¹⁸ In this respect, similar to the Court’s treatment of environmental protection,Footnote ¹¹⁹ the safeguarding of future generations and the principle of intergenerational burden-sharing operate only indirectly, as a ‘surrogate’ for protecting presently vulnerable groups. While this consideration reinforced the set of factors justifying legal representation, it did so by informing the Court’s conception of its institutional role in climate litigation, not by opening the door to abstract review.

A counterfactual question nonetheless arises: had the association lacked a statutory reference to future generations (as noted at paragraph 521), would locus standi still have been granted? A negative answer would imply that the Court elevated intergenerational protection to a conditio sine qua non for organizational standing, effectively instrumentalizing the represented elderly women to pursue broader climate objectives – an interpretation the Court expressly warns against.Footnote ¹²⁰ A positive answer, by contrast, affirms the centrality of the proven vulnerability of elderly women as the legal foundation for standing, thereby expanding the potential for organizations to litigate under the Convention. This reading aligns with the Court’s established doctrine of ‘special considerations’ and ‘exceptional circumstances’, long designed to prevent serious rights violations from evading judicial scrutiny and to clarify the Convention’s interpretative scope.

Seen in this light, KlimaSeniorinnen is no exception. The case enabled the Court to increment legal accountability for climate mitigation within an integrated European framework while avoiding abstract review or generalized access to justice. Absent its evolved, self-ascribed duty to contribute to intergenerational burden-sharing and climate mitigation, locus standi would probably have been denied and the case declared inadmissible. Crucially, however, this does not mean that the case was admitted because it advanced future policy or legislative goals. The relevance of intergenerational burden-sharing emerges only derivatively, as a ‘surrogate’ for protecting current victims. In this sense, Heri’s conclusion holds: cases arising from structural problems ‘are not necessarily actiones populares as long as they concern affected persons’, and public interest litigation under the ECHR must be understood ‘more broadly’ than actio popularis.Footnote ¹²¹ A similar rationale underpinned the Court’s findings on the Article 6 violation, where it criticized the domestic judiciary for equating climate-related applications – merely because they resonated with shared interests – to inadmissible actio popularis.Footnote ¹²²

As both Judge Eicke’s dissentFootnote ¹²³ and the initial reaction of the Swiss Parliament indicate, this ‘tailored approach’ exposes the Court to charges of judicial overreach. Yet it is more convincingly understood as a timely and carefully calibrated effort to ‘maintain both the Convention’s and [the Court’s] own relevance in the midst of one of the most pressing challenges facing humanity’.Footnote ¹²⁴ In this respect, the temporal context is far from incidental: the judgment aligned with a growing body of European climate litigation, at a time when the ECtHR risked forfeiting a critical opportunity to complement the principles of shared responsibility and subsidiarity with a concrete framework for legal accountability in climate protection.