The End of Plaumann in Climate Litigation: Now or Never?

Table of Contents: 1. Introduction. – 2. Plaumann in CJEU climate litigation cases before KlimaSeniorinnen. – 2.1. CJEU case law on the application of Plaumann in climate litigation. – 2.2. A critique of Plaumann: general points of criticism and applicability in climate litigation. – 2.2.1. Plaumann: One interpretation of many. – 2.2.2. A complete system of remedies? – 2.2.3. Why still Plaumann? – 3. Plaumann in CJEU climate litigation cases after KlimaSeniorinnen. – 3.1. Victim status and legal standing in KlimaSeniorinnen. – 3.2. Impact of KlimaSeniorinnen on Plaumann – 3.2.1. Interactions between the ECHR and the EU legal system. – 3.2.2. Revisiting Plaumann – 4. Conclusion.

Abstract: This article examines the possible impact of the ECtHR’s KlimaSeniorinnen judgment on the case law of the CJEU regarding legal standing of legal and natural persons. Specifically, it focuses on the implications of the ECtHR’s interpretation of victim status under Article 34 ECHR in KlimaSeniorinnen for the CJEU’s Plaumann test to determine legal standing for individual applicants under Article 263, paragraph 4, TFEU. The diverging approaches by the ECtHR and the CJEU towards the shared goal of preventing the possibility for an actio popularis in climate litigation cases are juxtaposed. This contribution critiques the static approach of the CJEU in this regard, which has interpreted the legal standing of individual applicants and associations rather restrictively in climate litigation, specifically in the cases of Carvalho and Sabo. Different points of criticism, especially regarding access to justice, are discussed. The article argues that the Plaumann test is not immutable and that the CJEU should reconsider its restrictive approach by taking inspiration from the novel approach applied by the ECtHR in KlimaSeniorinnen. While the CJEU may not be legally required to adopt the ECtHR’s standards on legal standing under EU law ‒ that is, until the EU's accession to the ECHR ‒ the KlimaSeniorinnen judgment could still have an indirect impact on the CJEU. Furthermore, the pending cases of Medel and Asociația Inițiativa pentru Justiție provide the CJEU with the occasion to address the continued relevance of Plaumann. Moreover, both AG Emiliou’s Opinion and the Court’s judgement in Nicoventures are critically assessed.

Keywords: climate litigation – legal standing – locus standi – victim status – actio popularis – KlimaSeniorinnen.

1.   Introduction

As has been acknowledged by the European Court of Human Rights (ECtHR) in KlimaSeniorinnen, ‘everyone may be, one way or another and to some degree, directly affected, or at a real risk of being directly affected, by the adverse effects of climate change.’[1]This simple truth leads into murky waters when applied to legal standing for individual applicants and associations in climate litigation cases. It begs the question how Courts can avoid allowing for actio popularis while steering clear of an overly restrictive understanding of locus standi.[2] The Court of Justice of the European Union (CJEU) and the ECtHR have adopted contrasting approaches thus far. This contribution seeks to analyse the implications of the KlimaSeniorinnen judgment for the CJEU’s future case law on legal standing for natural and legal persons.

The Plaumann test has been at the core of the legal standing test for private applicants in annulment procedures under Article 263, paragraph 4, TFEU before the CJEU for over 60 years.[3] Consequently, in its two most prominent climate litigation cases, i.e.,Carvalho and Sabo, the CJEU dismissed the applications due to lack of standing, citing the Plaumann criteria for individual concern.[4] However, after the KlimaSeniorinnen judgment by the ECtHR, it must be queried whether the CJEU will maintain this restrictive approach to the legal standing of individual applicants. Therefore, this contribution queries whether it is necessary to revisit Plaumann after KlimaSeniorinnen.

The article is based on the research question whether the Plaumann criteria should still be applied by the CJEU in climate litigation cases under the annulment procedure today in light of the recent ECtHR case law in KlimaSeniorinnen. Therefore, it adopts a normative approach. In order to answer the research question, the article mainly employs doctrinal legal analysis. Moreover, there is a brief section on the CJEU’s reasons for not abandoning Plaumann which relies on different political science methodologies (part 2.2.3.). Said section aims at offering a fuller picture of the CJEU’s approach by adopting an interdisciplinary lens.

There are several terms that need to be defined at the outset: climate litigation, actio popularis, strategic litigation, and public interest litigation. Firstly, climate litigation is defined, for the scope of this research, as ‘cases brought before judicial and quasi-judicial bodies that involve material issues of climate change science, policy or law’.[5] Secondly, an actio popularis is commonly defined in international law as a ‘right resident in any member of a community to take legal action in vindication of a public interest’.[6] In other words, it can be understood as a ‘right of “any person” to challenge [an] act or omission of a public authority before [an] administrative court, “sanctioned” by the legislator (established by law)’.[7] The ECtHR has held that the European Convention of Human Rights (ECHR) does not allow for an actio popularis as applicants are not allowed to ‘complain about a provision of national law simply because they consider, without having been directly affected by it, that it may contravene the Convention’.[8] Similarly, the EU legal order ‘does not recognize an actio popularis’ either.[9] Thirdly, strategic litigation forms part of legal mobilisation and can be defined as ‘legal action initiated to achieve broader social, political, or economic ends’.[10] Thus, strategic litigation can pursue either public or private interests.[11] Fourthly, public interest litigation, a concept rooted in the US legal tradition, traditionally has been defined as lawyers pursuing litigation for the ‘common good’.[12] Today, it can be understood as a ‘broad and contested range of activities that include legal advocacy focused on the representation of individuals shut out of the private market for legal services as well as lawyering to advance the collective interests of defined groups or constituencies (both liberal and conservative)’.[13]

The article is divided into three main parts. Firstly, relevant CJEU case law on the Plaumann test in general and regarding climate litigation will be briefly presented, along with the respective criticism by the literature (part 2). Secondly, the potential impact of the KlimaSeniorinnen decision on the CJEU’s future case law will be discussed (part 3), analysing various proposals for a different understanding of the concept of individual concern. Thirdly, a short conclusion will argue that the CJEU should ease its tight grip on the Plaumann criteria (part 4).

2.   Plaumann in CJEU climate litigation cases before KlimaSeniorinnen

2.1.  CJEU case law on the application of Plaumann in climate litigation

According to Article 263, paragraph 4, TFEU, private applicants have legal standing before the CJEU concerning acts not addressed to them that are ‘of direct and individual concern to them’. This contribution focuses on the criterion of individual concern, specifically on the Plaumann criteria adopted by the CJEU to define this term.[14] In the 1963 Plaumann case, the CJEU ruled that ‘[p]ersons other than those to whom a decision is addressed may only claim to be individually concerned if that decision affects them by reason of certain attributes which are peculiar to them or by reason of circumstances in which they are differentiated from all other persons and by virtue of these factors distinguishes them individually just as in the case of the person addressed’.[15] In the case at hand, the Court stated that ‘the applicant is affected by the disputed Decision […] by reason of a commercial activity which may at any time be practised by any person and is not therefore such as to distinguish the applicant in relation to the contested Decision as in the case of the addressee’[16]. Instead, in order to be able to be individually concerned by measures that affect a group of persons based on general and abstract criteria, the applicants must belong to a ‘closed group’.[17] Therefore, the Court declared the action for annulment by the Plaumann company inadmissible due to lack of individual concern.[18]

The debate surrounding the interpretation and application of the admissibility criteria for individual applicants has been described as ‘perennial’.[19] In the early 2000s, Advocate General (AG) Jacobs heavily criticized the Plaumann test in his Opinions in UPAand Jégo-Quéré.[20] AG Jacobs proposed a new interpretation of the criterion of individual concern, namely that ‘an applicant is individually concerned by a [Union] […] measure where the measure has, or is liable to have, a substantial adverse effect on his interests’.[21] In Jégo Quéré, the Court of First Instance (CFI; today, General Court, GC) even followed AG Jacobs in his critique of the Plaumann test. It proposed a new interpretation of ‘individual concern’ as meaning that ‘a natural or legal person is to be regarded as individually concerned by a [Union] measure of general application that concerns him directly if the measure in question affects his legal position, in a manner which is both definite and immediate, by restricting his rights or by imposing obligations on him’.[22] However, the CJEU did not adhere to the proposed new approaches but rather maintained the Plaumann test.[23]

To date, there have been two key cases of climate litigation before the CJEU which have been dismissed for lack of standing, namely the judgment in Carvalho (also known as ‘People’s Climate case’[24]) and the order in Sabo (also known as ‘EU Biomass case’[25]). Carvalho can be categorized as a so-called ‘government framework case’[26] since the applicants ‘challenge the ambition or implementation of climate targets and policies affecting the whole of a country’s economy and society’, or rather, in this particular setting, of the EU’s economy and society.[27] Sabo, on the other hand, does not seem to fit neatly into any of the established categories. It seems most likely that it could be framed as a case of climate washing regarding sustainable sources of energy since the applicants challenge ‘inaccurate government or corporate narratives regarding contributions to the transition to a low-carbon future’, or rather, in this case, an EU narrative concerning the presumed sustainability of biomass as a source of renewable energy.[28]

In Carvalho, the applicants consisted of more than 30 individuals, living in different EU Member States and third countries, as well as of the association Sáminuorra, established under Swedish law to protect the interests of Sámi Indigenous Peoples.[29] They sought annulment of the 2018 EU climate package as well as compensation for the damage they had allegedly suffered.[30] Regarding their legal standing, firstly, they claimed to be directly affected by the 2018 EU climate package since it allegedly violated their fundamental rights.[31] Secondly, they argued that they were individually affected since the ‘effects of climate change, to which the legislative package contributes, and, accordingly, the infringement of those rights will be unique to and different for each individual’.[32] In addition, they requested a more flexible interpretation of the Plaumann criteria, referring to the so-called ‘Plaumann paradox’ according to which ‘the more serious the damage and the higher the number of affected persons, the less judicial protection is available’.[33] This paradox becomes especially evident when applied to climate change: Climate change has negative impacts on every person to a certain extent, as the ECtHR has explicitly acknowledged.[34] This fact, under Plaumann, leads to the result that no one can challenge EU legal acts regarding such an all-encompassing phenomenon. 

In fact, the CJEU held that ‘the fact that the effects of climate change may be different for one person than they are for another and that they depend on the personal circumstances specific to each person does not mean that the acts at issue distinguish each of the appellants individually’, confirming the GC’s ruling.[35] Furthermore, the Court rejected the idea that the alleged violation of fundamental rights could lead to the assumption of individual concern.[36] Thus, the Court rejected the appeal against the GC’s application of the Plaumann criteria to this case.[37]

Additionally, the CJEU recalled that there are three groups of cases in which associations can be individually concerned under its case law: ‘firstly, where a legal provision expressly grants a series of procedural powers to trade associations; secondly, where the association represents the interests of its members, who would themselves be entitled to bring proceedings; and, thirdly, where the association is distinguished individually because its own interests as an association are affected, in particular because its negotiating position has been affected by the act in respect of which annulment is sought’.[38] In the first case, an association may be granted legal standing even though its members are not directly and individually concerned if a EU law provision foresees a procedure before the adoption of a decision ‘under which a person is entitled to claim rights that might be available to him, including the right to be heard’.[39] In the second case, an association challenging a legal act for the protection of collective interest is considered individually concerned if at least some of its members fulfil the Plaumann criteria.[40] In the third case, the association must ‘prove an interest of its own’, e.g., by being a ‘negotiator of the discipline’ with the Commission.[41] In Carvalho, the association Sáminuorra did not fulfil any of these criteria. Furthermore, these criteria do not allow for public interest litigation.[42]

In Sabo, the applicants, similarly to Carvalho, were mostly comprised of individuals from various EU Member States as well as of associations with their respective seats in various Member States.[43] The applicants sought a partial annulment of directive 2018/2001[44] insofar as this directive frames forest biomass as a source of renewable energy.[45] They argued that they were individually concerned by the directive since they form ‘part of a limited category of persons that is affected by the deforestation and the operation of power plants which the directive causes’.[46] Furthermore, they alleged that their individual legal interests and fundamental rights were being violated.[47]

Nonetheless, the CJEU held that, given that the directive applies to all legal and natural persons in the EU, the applicants ‘were not in a situation which was different from that of the indeterminate and indeterminable body of EU citizens and were, therefore, not differentiated by the fact of holding a specific acquired right’.[48] Moreover, the Court stated that the claim that the applicants’ fundamental rights were violated cannot constitute individual concern, ‘without running the risk of rendering the requirements of the fourth paragraph of Article 263 TFEU meaningless’.[49]

In conclusion, the CJEU has thus far adopted a highly restrictive interpretation of the criterion of individual concern in climate litigation cases under Article 263, paragraph 4, TFEU by applying the Plaumann test.[50]

Furthermore, the issue of the continued relevance of Plaumann is timely not only regarding climate litigation, but also concerning other areas of substantial law. This finding is supported inter alia by the pending appeal in Medel, which concerns the rule of law conditionality regarding Next Generation EU (NGEU) funds.[51] In their appeal, the applicants challenge the ‘application of the Carvalho case law’ by invoking, inter alia, ‘the KlimaSeniorinnen jurisprudence of the European Court of Human Rights’.[52]In addition, the General Court has explicitly addressed the issue of the influence of KlimaSeniorinnen on Article 263, paragraph 4, TFEU in Asociația Inițiativa pentru Justiție (for more detail, see section 3.2.1).[53] Furthermore, recently, AG Emiliou has substantively contributed to the discussion around Plaumann with his Opinion in Nicoventures since, in his view, this case offered ‘the Court the opportunity to revisit’ the Plaumann case law.[54] Nicoventures concerned the prohibition of flavoured heated tobacco products.[55] In the Opinion, the AG called for a ‘a more supple and realistic application’[56] of the Plaumann case law, as will be explained in more detail below (part 3.2.2.). While the Court did not follow the AG’s Opinion, the AG’s proposals will, nevertheless, be discussed. The Opinion represents a crucial development in the discussion of the continued relevance of the Plaumann test. Hence, the Court has and has had more than one occasion to discuss the continued relevance of the Plaumann test, albeit not in the climate litigation context. Those cases show, firstly, that Plaumann is anything but an old hat. Secondly, the Plaumann doctrine poses problems not only regarding environmental and climate litigation, but also regarding other crucial areas, such as the rule of law.

2.2   A critique of Plaumann: general points of criticism and applicability in climate litigation 

The Plaumann test has been controversial for a long time, even before the phenomenon of climate litigation emerged.[57] As shown in section 2.1, AG Jacobs already heavily criticized the Plaumann case law more than 20 years ago. As critical voices in the literature point out, the Court ‘reiterates the same reading of the Treaty provisions on access to justice in a very static and rigid way.’[58] In an almost Kafkaesque manner,[59] the approach of the Court has been: ‘Plaumann means Plaumann means Plaumann’.[60] The Court seems to be unwilling to question its own interpretation, even in the face of the ongoing and outspoken criticism by some of its AGs and many academics.[61]

In recent years, the criticism of Plaumann has been voiced with increasing fervour regarding environmental and climate litigation. As has been pointed out in the literature, it is noteworthy that in Carvalho and Sabo, there were neither AG opinions nor referrals to the Grand Chamber.[62] Furthermore, both of the rulings are noticeably short. Moreover, the final decisions are only available in English and French on the CURIA database instead of in all the official languages of the EU.[63] These formalistic observations alone could create the impression that the Court has not attributed great relevance to them. In fact, one might argue that the question of individual concern in climate litigation cases did indeed raise new points of law, rendering an AG opinion necessary.[64] Thus, it is true that the ʻemphasisʼ placed by the ECtHR and the CJEU respectively on cases dealing with climate change is notably different, with the CJEU cases being much less in the spotlight than the ECtHR cases so far.[65]

On substance, it has been observed that Plaumann poses ‘an insurmountable barrier for private parties to challenge EU legislative acts on climate-related issues’[66] since its restrictive interpretation renders access to the CJEU close to impossible in environmental and climate cases.[67] Winter, a counsel to the applicants in Carvalho, has even argued that the Plaumann test does not call for individual, but rather for ‘exclusive’ concern in climate cases.[68] While it is true that this criticism often seems to be ‘outcome driven’,[69] the substantive arguments against the Plaumann case law shall nevertheless be explored. The following sub-sections provide a general critique of Plaumann, applying the criticism to the climate litigation context and juxtaposing the CJEU’s approach with the critique in the literature.

2.2.1.   Plaumann: one interpretation of many

The CJEU has argued, in different ways, that the Plaumann test represents the only possible interpretation of the criterion of individual concern under Article 263, paragraph 4, TFEU.

Firstly, in Carvalho and Sabo, the CJEU stated that accepting a wider interpretation of the locus standi for the applicants in the case would ‘render the requirements of the fourth paragraph of Article 263 TFEU meaningless and would create locus standi for all without the criterion of individual concern referred to in the judgment in Plaumann being fulfilled’.[70] This argumentation has been aptly described as a ‘classic circulus in probando: the limit of Plaumann is Plaumann’.[71] Moreover, this passage seems to display the Court’s ‘fear of softening the standing requirements, which might lead […] to a scenario of actio popularis’.[72]

The CJEU’s approach seems problematic, as it conflates the wording of the Treaty text with the CJEU’s own interpretation of said text. The CJEU continues to rely on ‘a formulaic method’,[73] alleging that Plaumann is intrinsically linked to the Treaty formulation. This approach is not convincing since Article 263, paragraph 4, TFEU only refers to direct and individual concern as general terms, not to a specific interpretation of those terms.[74] In fact, in the words of AG Jacobs, ‘the notion of individual concern is capable of carrying a number of different interpretations’.[75] Thus, the Plaumann test is only one of several possible interpretations of the notion of individual concern.[76] Several proposals for different interpretations will be analysed in section 3.2.2. For instance, AG Jacobs argued in his conclusions in UPA that there are ‘no compelling reasons to read into that notion a requirement that an individual applicant seeking to challenge a general measure must be differentiated from all others affected by it in the same way as an addressee’.[77] Therefore, there seems to be no legal basis for stating that without the Plaumann criteria Article 263, paragraph 4, TFEU would be stripped of its meaning.

Secondly, the Court alleges that interpreting legal standing for private applicants in a broader way would require a Treaty change by the Member States since a more lenient interpretation of the individual concern criterion would mean an excess of the CJEU’s competences.[78] However, the Plaumann test, as has been shown above, is a product of the CJEU case law and not expressly enshrined in the Treaties.[79] Therefore, it is not convincing that a Treaty change would be legally required. Instead, the CJEU itself is competent to adopt a certain interpretation of the criterion of individual concern.[80] At least in theory, there is no stare decisisobligation for the CJEU.[81] Nonetheless, in practice, the CJEU seems to rely on binding precedents, using the ‘overruling technique’ when departing from previous case law.[82] In fact, turning the back on legal precedents may lead to problems regarding ‘legal certainty, coherence and res iudicata’.[83] Thus, the CJEU uses varying degrees of overruling carefully.[84] In the case of Plaumann, the CJEU could overrule or adapt the test without the need for a Treaty change. In this case, there would be the need for a reconsideration or an express overruling, respecting the principles of legal certainty, coherence, and res iudicata.

In support of this argument, it must be remembered that in other areas, the CJEU has interpreted the standing requirements of Article 263, paragraph 4, TFEU innovatively and teleologically. For instance, in the Venezuela case, it stated that ‘an interpretation of the fourth paragraph of Article 263 TFEU in the light of the principles of effective judicial review and the rule of law militates in favour of finding that a third State should have standing to bring proceedings, as a “legal person” within the meaning of the fourth paragraph of Article 263 TFEU’.[85] Thus, the Court has shown that it is willing to interpret the criteria set forth in Article 263, paragraph 4, TFEU in an evolving manner, giving priority to the principles of effective judicial review and the rule of law.[86] In the 1990 case of Parliament v Council, the Court even attributed legal standing to the European Parliament, even though this institution was not explicitly granted standing under Article 263 TFEU’s predecessor, Article 173 EEC Treaty.[87] Naturally, none of the cases mentioned in this paragraph are focused on the criterion of individual concern, as they centre around other aspects of Article 263, paragraph 4, TFEU. However, on a more abstract level, they show that the CJEU has taken major interpretative liberty regarding the criteria of Article 263 TFEU in the past, even going against the Treaty text in Parliament v Council. 

It has been argued by Van Wolferen that the CJEU’s ‘power as the final arbiter of the Treaty has, from the inception of the European project, been limited when it comes to all applicants’.[88] He bases this argument on the fact that the CJEU had been awarded a rather limited mandate at the beginning of European integration and that the subsequent Treaty changes had not extended the interpretative margin of the Court regarding individual concern.[89] However, it seems from the case law mentioned in the previous paragraph that the CJEU has interpreted the criteria of Article 263 TFEU in a more flexible manner if a novel legal situation requires such an approach, i.e., regarding the European Parliament and third States.[90]

In support of the argument that Plaumann is not inevitable, it needs to be pointed out that in various cases, the CJEU does not apply the Plaumann criteria consistently in certain areas of substantive law, such as competition law, state aid, and anti-dumping, as has been noted in the literature.[91] It has been proposed that the following three groups of case law constitute individual concern: firstly, formal participation in the administrative procedure adopting the legal act, e.g., Metro;[92] secondly, when economic operators have already been conclusively determined to be affected by a certain legal act, e.g., Sofrimport; thirdly, applicants that are affected in specific market positions or rights, such as trademark rights, e.g., Extramet and Codorníu.[93] However, it seems questionable whether Extramet and Codorníu belong in the same category since the exclusive market position in Extramet is different from the trademark right in Codorníu as the former is a factual, not a legal attribute. In these areas, especially in anti-dumping, the ‘comparative view imbedded in the formal “distinctiveness” test vanishes and a substantial orientation that looks at severity for the individual actor creeps in’ when determining their market position.[94] The Court appears to be ‘more liberal’ in these areas.[95] This contrast is illustrated by the juxtaposition of the cases Timex and WWF-UK v Council.[96] On the one hand, the Court held in Timex, an anti-dumping case, that ‘the part played by the applicant in the anti-dumping proceedings’[97] was part of why the applicant was considered individually concerned by the measure in question.[98] In particular, Timex had lodged a complaint which was rejected by the Commission, similarly to the complaint at the base of the investigation procedure, and had been heard in the procedure leading to the adoption of the contested measure.[99] On the other hand, the CJEU set out a two-step test in WWF-UK, a case concerning sustainable fishing practices. Firstly, the Court stated that a person ‘involved in the procedure leading to the adoption of a [EU] […] measure’ is considered individually concerned ‘only if the applicable [EU] […] legislation grants him certain procedural guarantees’.[100] Secondly, according to the Court, ‘the mere fact of relying on the existence of a procedural guarantee before the Community judicature does not mean that an action will be admissible where it is based on pleas alleging the infringement of substantive rules of law’.[101] In the second case, the Court appears to set much higher standards for accepting individual concern based on the participation in the procedure leading to the adoption of the measure in question.

This case law begs the question whether the CJEU applies the Plaumann test consistently and in an unbiased fashion when determining legal standing for private applicants.[102] Until now, the CJEU only seems to relax the Plaumann test in cases where a legal person alleges a violation of its economic interests.[103] Thus, the Court appears to interpret the requirement of individual concern as privileging (private) economic over public interests.[104] In fact, the Court has been criticized for applying a ‘double standard’.[105] On the one hand, some authors discussing environmental litigation have alleged that the CJEU sticks to the Plaumanncriteria for ideological reasons since it would not ‘wish to see environmental organizations or individuals raise the infringement of environmental provisions by EU institutions before the Court’.[106] It has been argued that the choice to prefer economic motives is ‘questionable’.[107] On the other hand, some argue that economically relevant positions, e.g., trademark rights as in Codorníu, are ‘more suitable for clearly distinguishing an individual from others in a similar way to an addressee of a single-case decision’.[108]This last argument certainly holds some truth concerning the practicability of the criteria, but it is difficult to assess whether this is the sole reason why the Court is willing to accept individual concern in some cases that do not quite fit under the Plaumann test exclusively when they relate to economic interests. It can be inferred from the above-mentioned case law that Plaumann is not, as the Court alleges, a one-fits-all solution to assess individual concern under Article 263, paragraph 4, TFEU.[109]

However, some authors do not fully agree with this ‘double standard’ criticism, which has been described as ‘too simplistic’.[110]Pagano raises two objections to this argument. Firstly, he states that the Court has ‘refused to grant standing to private corporations even in competition and State Aid cases in a significant number of rulings’.[111] Secondly, he recalls that the CJEU in the 1988 Commission v Denmark case has held that environmental protection can be used to justify restrictions on the four freedoms.[112] In Pagano’s view, these arguments are proof that the CJEU ‘does not favour corporate interests over environmental interests in absolute terms’.[113]However, on the first argument, it could be argued that a more robust quantitative analysis would be needed to render this point on the ‘significant number of rulings’ more convincing. Moreover, the fact that the Court appears to be inconsistent even in these areas shows that the Plaumann case law remains too opaque. Regarding the second argument, it could still be said that criticizing the Court’s inconsistent approach to legal standing for environmental NGOs does not necessarily entail implying that the CJEU is (or was) ‘anti-environmental’ ‘in absolute terms’. The double-standard criticism can still be valid when confined to the specific area of legal standing.

Pagano instead proposed to distinguish between ‘acts of quasi-judicial nature’ and ‘acts based purely on policy and discretion’, basing his analysis on Hartley’s work.[114] In this framework, individual concern for ‘acts of quasi-judicial nature’, on the one hand, is defined based on ‘objective consideration’ and adopted through a ‘procedure which has judicial features’.[115] On the other hand, there are two tests for ‘acts based purely on policy and discretion’. Firstly, there is a ‘small group test’ for when a ‘measure is drafted in general terms but the persons affected, though members of a theoretically open category, in fact consist of a small and easily identifiable group’.[116] Secondly, the ‘closed category test’ applies in two cases, either when a ‘measure though drafted in abstract terms, applies (in whole or in part) to a closed category of persons’[117] or when the measure is a regulation[118]. According to Pagano, ‘Hartley’s distinction can therefore help to understand not only the Court’s rigidity on Plaumann in the field of environmental protection, but also the so called “double standard” of the EU judiciary when dealing with cases in different legal domains’.[119] Nonetheless, while being an interesting lens through which cases concerning individual concern can be categorized, Hartley’s approach does not seem to leave room for environmental and climate cases at all, since they do not seem to fit in any of his categories.

2.2.2.   A complete system of remedies?

In addition to the argument that Plaumann is the only possible interpretation of the criterion of individual concern, the Court also relies on another line of reasoning, i.e., on a more systemic argument. In fact, the Court argues that the EU legal order is based on a ‘complete system of remedies’[120], leaving individual applicants the option to instigate proceedings before national courts which can initiate a preliminary reference procedure before the CJEU as an indirect action if direct actions, such as an annulment procedure, are not admissible.[121] This means that ‘there will be no possible means by which any act will be able to exist without being open to review by the Court’.[122]

However, as stated already by AG Jacobs in UPA, ‘[p]roceedings before national courts do not […] always provide effective judicial protection of individual applicants and may, in some cases, provide no legal protection whatsoever’.[123] As is well-known, national courts cannot declare measures of EU law invalid.[124] Moreover, applicants cannot legally enforce that national courts refer any preliminary questions to the CJEU.[125] Furthermore, even if the national courts choose to refer preliminary questions to the CJEU, the formulation of the preliminary questions remains within the competence of the national courts, not of the applicants.[126] Lastly, according to AG Jacobs, it is extremely cumbersome to challenge EU acts which do not call for any act of implementation by national authorities.[127] On this point, it must be remembered, however, that for once, the Lisbon Treaty has introduced the third limb of Article 263, paragraph 4, TFEU, resolving this problem at least regarding regulatory acts, i.e., non-legislative acts of general application.[128] Moreover, the Court has held in BAT that ‘[t]he opportunity open to individuals to plead the invalidity of a[n] [EU] […] act of general application before national courts is not conditional upon that act’s actually having been the subject of implementing measures adopted pursuant to national law’.[129] In addition, when indirectly challenging EU law through domestic procedures, the overall duration and costs of the procedures before the national court, the CJEU and, again, the national court will likely be higher than those for a direct action.[130] According to AG Jacobs, in terms of effective judicial protection, Article 267 TFEU and Article 263, paragraph 4, TFEU do generally not offer the same level of agency and protection to individual applicants.[131]

Furthermore, it has been correctly stated by AG Bobek that the ‘architecture’ of the EU judicial system has profoundly changed over the last decades:

‘Jurisprudentially restricting direct access, while generously allowing for the indirect one via the preliminary ruling procedure, was perhaps a good recipe in the early 2000s. However, with the radically changed structure of the EU Courts some 20 years later, the insistence that there still be limited access through the door which has capacity, while allowing for unfettered access on the same issues through the other door which, by now, has limited capacity, is bound to lead to congestion and an evident lowering of the quality of the traffic’.[132]

Regarding climate litigation, the preliminary reference procedure seems to be inapt to address government framework climate litigation cases[133] like Carvalho against EU legislative acts in particular.[134] In fact, it would be difficult to imagine a case where a national court would have to refer a question on the compatibility of EU climate legislation with primary law in order to be able to solve a domestic dispute.[135] As Schlake points out, this would only make sense if the ‘unambitious’ EU legislation stood in the way of a more ambitious policy on the Member State level.[136] However, according to Article 193 TFEU, climate protection is an area of minimum harmonisation, leaving Member States the freedom to maintain or adopt ‘more stringent protective measures’, if they wish to do so.[137]Thus, there seems to be little hope for a preliminary procedure in framework cases, such as Carvalho or KlimaSeniorinnen.[138]

Moreover, as is well-known, in European Parliament v Council, the Court held that the other procedural avenues available to the Parliament at the time were ‘not sufficient to guarantee, with certainty and in all circumstances’, that the European Parliament’s goal of judicial review was achieved.[139] Thus, in this case, the CJEU itself did not deem the ‘complete system of remedies’ sufficient to protect the principle of institutional balance. This argument could be replicated by underlining that preliminary reference procedures are ‘not sufficient to guarantee, with certainty and in all circumstances’ to ensure the individual applicant’s goal of reviewing the EU climate legislation, potentially violating the principle of effective legal protection, today enshrined in Article 47 Charter of Fundamental Rights of the European Union (CFR). Thus, adopting the same logic, it seems preferable to ensure access to the CJEU for private applicants through direct actions at least in cases in which a preliminary reference procedure would not seem possible, such as in framework cases against EU legal acts regarding climate targets.[140]

Indeed, the restrictive understanding of individual concern in climate cases must be questioned in light of the issue of access to justice, i.e., the right to an effective remedy under Article 47 CFR and under Article 9, paragraph 3, of the Aarhus Convention.[141]

Firstly, the compatibility with Article 47 CFR must be assessed.[142] On the one hand, it is true, as the Court held in Carvalho, that ‘the protection conferred by Article 47 CFR does not require that an individual should have an unconditional entitlement to bring an action for annulment of such a legislative act of the Union directly before the Courts of the European Union’.[143] In the same vein, it is clear that an interpretation in conformity with Article 47 CFR cannot lead to ‘setting aside the conditions expressly laid down in that Treaty’.[144] On the other hand, no right to unconditional access to the CJEU does not equal no right to access to justice at all. It is questionable whether there is another effective legal remedy available in (framework) climate litigation cases. In fact, it has been argued that applying the Plaumann criteria in climate litigation cases could amount to a denial of justice.[145] In addition, as shown above, an interpretation in conformity with Article 47 of the Charter does not mean setting aside the conditions established by the Treaty. At most, it would mean setting aside the Plaumann test, which, as pointed out above, is not established by the Treaties.

Secondly, the question of access to justice must be analysed in the light of the Aarhus Convention. The Aarhus Convention was adopted as an international agreement in 1998 and entered into force in 2001. Among the currently 48 parties to the agreement are both the EU and all EU Member States.[146] It is built on three pillars: access to information, public participation in decision making, and access to justice in environmental matters.[147] In the context of Plaumann, the third pillar is of particular importance. Article 9, paragraph 3, Aarhus Convention states that parties to the Convention, such as the EU, shall ensure that ‘members of the public have access to […] judicial procedures to challenge acts and omissions by […] public authorities which contravene provisions of its national law relating to the environment.’ The CJEU has held in Brown Bear I that this provision lacks direct effect.[148]

In 2006, shortly after having ratified the Convention, the EU adopted the Aarhus Regulation, adapting the Aarhus Convention to the context of the EU institutions.[149] The Regulation has been updated in 2021.[150] According to Article 10 of the Regulation, ‘[a]ny non-governmental organisation or other members of the public […] shall be entitled to make a request for internal review to the Union institution or body that adopted the administrative act or, in the case of an alleged administrative omission, should have adopted such an act, on the grounds that such an act or omission contravenes environmental law’. Article 12 of the Aarhus Regulation states that the NGO ‘which made the request for internal review pursuant to Article 10 may institute proceedings before the Court of Justice in accordance with the relevant provisions of the TFEU’.

Against this background, it must be recalled that the Plaumann criteria as well as the Aarhus Regulation have also been criticized for their incompatibility with the Aarhus Convention[151]. In the absence of direct effect of the provisions of the Aarhus Convention, Article 263, paragraph 4, TFEU must be interpreted consistently with Article 9, paragraph 3, Aarhus Convention.[152] The Aarhus Convention Compliance Committee (ACCC) has held that the formulation of Article 9, paragraph 3, of the Aarhus Convention (‘the criteria, if any, laid down in national law’) implies ‘self-restraint on the parties not to set too strict criteria’ and that ‘[a]ccess to such procedures should thus be the presumption, not the exception.’[153] The ACCC has concluded that the EU has not respected Article 9, paragraph 3, of the Aarhus Convention, arguing that the Plaumann criteria in their current form are ‘too strict to meet the criteria of the Convention’.[154] Subsequently, the EU amended the Aarhus regulation in 2021, as mentioned above. However, this reform did not lead to a revision of the Plaumann criteria, but only added, inter alia, the possibility for ‘other members of the public’ to launch an internal review request and broadened the definition of ‘administrative act’. Therefore, the EU seems to remain non-compliant with Article 9, paragraph 3, of the Aarhus Convention regarding legal standing for individuals.[155]

In any case, it must be remembered that the Aarhus Convention has a limited scope of application. While the Aarhus Convention does not explicitly cover climate-change litigation, voices in the literature have proposed to adopt a teleological interpretation of Article 9 Aarhus Convention in order to extend its scope of application to climate change.[156] The CJEU does seem to interpret the Aarhus Convention in this broader sense, which also encompasses climate litigation cases.[157] Notably, the ECtHR has not followed this interpretation in KlimaSeniorinnen.[158]

Moreover, the Aarhus Convention does not cover legislative, but only administrative acts.[159] Therefore, Article 9, paragraph 3, of the Aarhus Convention cannot affect the interpretation of Article 263, paragraph 4, TFEU regarding acts adopted through the legislative procedure.[160] For this reason, the scope of application of the Aarhus Convention in climate litigation cases is limited.

However, while the theoretical implications of Article 47 CFR and Article 9, paragraph 3, Aarhus Convention militate for a different interpretation of legal standing for individuals, there will be no legal consequences if the CJEU does not (fully) respect this right. No Court could condemn the CJEU since, as is well known, there is no higher court on the EU level.[161] Nonetheless, the EU’s potential accession to the ECHR would change this situation.[162] In the case of accession, it could be argued by the ECtHR that the CJEU does not fully respect Article 6 ECHR.[163] Nonetheless, until the actual accession of the EU becomes more concrete, this remains little more than a thought experiment. Regarding the compliance with the Aarhus Convention, on the other hand, the ACCC could issue new reports on the EU’s (non-)compliance with the Convention. It must be noted, however, that those reports are not legally binding.[164] However, at the Meeting of the Parties in Geneva in November 2025, the EU was found to have reached compliance with the ACCC findings concerning access to justice concerning State aid procedures (ACCC/C/2015/128), which could be seen as testament to the general willingness of the EU to work towards compliance with the Aarhus Convention, without changing the criteria for legal standing.[165]

In conclusion, the argument relating to the complete system of remedies does not appear to be fully convincing.[166]

2.2.3.   Why still Plaumann?

In light of the foregoing, one might question why the Court has not yet overruled Plaumann, notwithstanding the broad criticism over the years. Eliantonio and Stratieva have relied on three different theories from political science to shed light on the CJEU’s position: firstly, rational choice; secondly, historical institutionalism; thirdly, path dependency.[167]

Firstly, according to rational choice theory, the Court only acts in an ‘activist manner’ when it reckons that such activism will be approved by the Member States.[168] Consequently, ‘[t]he fact that, in UPA and Jégo-Quéré, the ECJ refrained from initiating reforms could thus be regarded as a reflection of the Court’s expectations that the Member States would disapprove of it’.[169]Against this interpretation, one might say that the Court has adopted bold stances against the Member States’ resistance on various occasions in the past.[170] Therefore, this first theory alone does not seem entirely convincing.

Secondly, according to historical institutionalism, the CJEU could be motivated by self-interest, either to protect itself from an overwhelming caseload (‘docket control’) or to preserve the integrity of EU legal acts.[171] This theory seems plausible but lacks concrete evidence. Further research would be required to strengthen this argument. Regarding ‘docket control’, it is often stated that the overwhelming workload for CJEU judges constitutes a major problem.[172] It seems that the judges expect a wave of (climate) litigation brought by individuals and associations in case they relaxed Plaumann.[173] While no definitive judgments can be made in this regard, one should nonetheless take account of the practical implications a wider understanding of locus standi for private applicants might have on the CJEU and its workload. In overturning Plaumann, the Court would have to be extremely careful not to open its doors too wide. This must also be monitored and reevaluated in the context of the recent reform of the division of competences between CJ and GC for preliminary rulings.[174] In any case, the fears of actio popularis seem to be overstated since it has been shown in the literature that even in countries which allow for actio popularis or broad standing rules in environmental matters, there has been no extreme increase in cases filed.[175] While this observation cannot be directly applied to climate litigation on the EU level, AG Jacobs has already put forward in his Opinion in UPA that he was

‘not convinced that a relaxation of the requirements for individual concern would result in a deluge of cases which would overwhelm the judicial machinery. There is no record of that having happened in those legal systems, inside and outside the European Union, which have in recent years progressively relaxed their requirements for standing. […] It may be thought that a relaxation of the requirements for standing would therefore result in an increase in the number of applications under the fourth paragraph of Article 230 EC which, though appreciable, would not be insuperable.’[176]

In addition, as has been pointed out by AG Sharpston in Djurgården-Lilla Värtans Miljöskyddsförening,

‘[b]y encouraging people to channel environmental disputes through non-governmental organisations promoting environmental protection, the Aarhus Convention and Directive 85/337, as amended, recognise that these organisations do not overload or paralyse the courts. Rather, they bring together the claims of many individuals in a single action. Although it is true that nothing prevents members of a non-governmental organisation also taking part in proceedings on an individual basis, the overall result of this policy is to create a filter which, in the long run, assists the work of the courts.’[177]

This assessment by AG Jacobs and AG Sharpston shows, firstly, that the CJEU must not be afraid of the floodgates being opened. Secondly, AG Sharpston’s Opinion supports the view that the CJEU should be more open towards access to justice for associations, ensuring both compliance with the Aarhus Convention and greater efficiency of the Court. Otherwise, there could be the risk that the CJEU might ‘deprive some interested parties of a voice and penalize the effectiveness of the court proceedings by depriving the bench of valuable sources of information’.[178] Indeed, the CJEU, constrained by its mandate, seems to be unable to deal with climate cases as part of public interest litigation,[179] which promote, ‘albeit indirectly, the interests of all victims of climate change’.[180] Regarding environmental issues, the importance of public interest litigation has been highlighted by different AGs in the past.[181] The legitimacy and impacts of strategic litigation before the CJEU remain understudied.[182] In the future, such considerations should guide the debate around legal standing for individuals and associations. The Court’s understanding of its mandate should, therefore, evolve towards being more inclusive towards public interest litigation in environmental and climate litigation.[183] In conclusion, the dangers of actio popularis in practice should generally not be overstated.[184] Lastly, legally, ‘docket control’ would be ‘hardly a convincing or legitimate justification’ for restricting access to justice in environmental or climate cases.[185]

Regarding the Court’s willingness to preserve EU legal acts, it must be observed that a similar tendency to shield secondary EU law from legal review exists also in other areas, such as in the CJEU jurisprudence regarding the direct effect of EU international agreements. In this area, the CJEU seems more ready to accept direct effect for the norms of international agreements in cases in which acts by Member States are challenged than in cases in which acts of EU secondary law are under review.[186] This dynamic is mirrored by the CJEU’s approach to climate and environmental cases, with the CJEU adopting some rulings in favour of stricter measures when addressing Member State legislation, such as in the Deutsche Umwelthilfe and Janecek cases.[187] However, as has been highlighted in this article, when it comes to EU acts, the CJEU hides behind its restrictive standing criteria. The same applies to the implementation of Article 9, paragraph 3, Aarhus Convention, since the Court demands that national courts interpret their standing criteria consistently with said provision, while the Luxembourg judges themselves do not seem to be willing to conform the standing criteria of Article 263, paragraph 4, TFEU to the Aarhus Convention.[188] Admittedly, from a strictly formalistic perspective, this could be seen as a natural result of the in the hierarchy of norms since international agreements rank between the Treaties and secondary law.[189] However, as pointed out by AG Bobek in Région de Bruxelles-Capitale, the CJEU has held in its case law that ‘primary law can and should be interpreted, where appropriate and as far as possible, in conformity with international law’.[190] Therefore, as AG Bobek argues,‘[w]hat is required of the national courts must also be required of the EU Courts’.[191]Otherwise, there is the risk of creating an unjustifiable double standard.[192] In addition, from a policy perspective, this Janus-like approach by the CJEU towards compliance with international law should be further studied in future research.

Thirdly, under the lens of path dependency, the ‘rigidity of the conditions for standing could be attributed to the constraints of long-standing case law which cannot be easily discarded’.[193] According to Eliantonio and Stratieva, the ‘costs of reversing […] [the case law on legal standing for individuals] would include not only a higher case load, but also loss of legal certainty’.[194] This theory seems quite probable. However, as laid out above, the CJEU can change its case law while still respecting legal certainty.

In conclusion, the three theories provide valuable insight into the Court’s reasoning. However, none of them can fully grasp the Court’s motivation.

3.   Plaumann in CJEU climate litigation cases after KlimaSeniorinnen

3.1.  Victim Status and Legal Standing in KlimaSeniorinnen

KlimaSeniorinnen was the first case in which the ECtHR explicitly ruled on the unprecedented legal implications of climate change, distinguishing the issue explicitly from its environmental case law.[195] The Court clearly stated that ‘climate change is one of the most pressing issues of our times’.[196] It recognized that the ‘widely acknowledged inadequacy of past State action to combat climate change globally entails an aggravation of the risks of its adverse consequences, and the ensuing threats arising therefrom, for the enjoyment of human rights’.[197] This case is further proof that the Convention is defined as a ‘living instrument which must be interpreted in the light of present-day conditions’.[198] The Court has ruled that Switzerland has violated Articles 8 (right to respect for private and family life) and 6 (right to a fair trial) ECHR by failing to adopt effective measures against the negative impacts of climate change and denying the KlimaSeniorinnen association access to Swiss courts.[199]

Victim status under Article 34 ECHR generally means that the ‘applicant must be directly affected by the impugned measure’, establishing the most common case in which the applicant is a direct victim of the measure(s) at stake.[200] It represents an autonomous notion not synonymous with categories of national law such as legal standing.[201] The attribution of victim status requires a ‘sufficiently direct link between the applicant and the harm which they consider they have sustained on account of the alleged violation’.[202] In contrast to the Plaumann test, victim status under the ECHR can even be granted when a potentially indefinite number of people is affected by the measure in question.[203] Thus, under the ECHR, it is not a conditio sine qua non for admissibility that an ‘individual victim must be affected differently from others’.[204] Instead, Article 34 ECHR covers direct victims as well as, under certain conditions, indirect, and potential victims.[205]

The applicants in KlimaSeniorinnen consisted of the ‘Verein KlimaSeniorinnen Schweiz’, a non-profit association established under Swiss law, and four elderly women as individual applicants, who are members of the applicant association.[206] As a preliminary observation regarding the victim status and legal standing in this case, the Court acknowledged the thorniness of defining victim status and locus standi in climate cases since ‘the number of persons affected, in different ways and to varying degrees, is indefinite’.[207] Furthermore, the Court reiterated that the notion of victim status must not be interpreted in a ‘rigid, mechanical and inflexible way’, but rather ‘in an evolutive manner in the light of conditions in contemporary society’.[208] The Court thus stated that the requirement of a ‘special approach to victim status, and its delimitation, therefore arises from the fact that complaints may concern acts or omissions in respect of various types of general measures, the consequences of which are not limited to certain identifiable individuals or groups but affect the population more widely.’[209] Moreover, the ECtHR argued that ‘any excessively formalistic interpretation of that concept would make protection of the rights guaranteed by the Convention ineffectual and illusory.’[210]

Firstly, the ECtHR assessed the victim status of the four individual applicants. The ECtHR acknowledged that an overly broad interpretation of the victim status in climate cases would ‘risk disrupting national constitutional principles and the separation of powers by opening broad access to the judicial branch as a means of prompting changes in general policies regarding climate change’.[211] But, in contrast to the CJEU, the ECtHR also sees a risk in drawing ‘this circle […] too tightly and restrictively’[212], since this could potentially lead to the result that ‘even obvious deficiencies or dysfunctions in government action or democratic processes could lead to the Convention rights of individuals and groups of individuals being affected without them having any judicial recourse before the Court’.[213] The Court therefore adopts a new understanding of victim status for individual applicants, tailored to the specific situation in climate litigation cases.

The ECtHR sets two factors as criteria for the victim status of individuals in climate cases. For once, ‘the applicant must be subject 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’.[214] In addition, ‘there must be a pressing need to ensure the applicant’s individual protection, owing to the absence or inadequacy of any reasonable measures to reduce harm’.[215] In its assessment of these criteria the Court will, amongst other considerations, take into account ‘the nature and scope of the applicant’s Convention complaint, the actuality/remoteness and/or probability of the adverse effects of climate change in time, the specific impact on the applicant’s life, health or well-being, the magnitude and duration of the harmful effects, the scope of the risk (localised or general), and the nature of the applicant’s vulnerability’.[216] In order to exclude an actio popularis, the Court considers the threshold for fulfilling the two above-mentioned criteria as ‘especially high.’[217]

Secondly, the ECtHR discusses the criteria under which associations have legal standing in climate cases. According to the Court, civil society associations can be victims under Article 34 ECHR if the Convention right in question can also be enjoyed by legal persons, e.g., procedural rights under Article 6 ECHR.[218] In contrast, a legal person cannot be a victim of a violation of Article 8 ECHR. Consequently, it is important to note the difference between victim status and legal standing in this regard as the ‘latter relates to the questions of representation of the (direct) victims’ complaints before the Court’ and might also be called ‘representation’.[219]Notably, the Court has traditionally been hesitant to admit legal standing for applicants who themselves were not victims.[220] In general, the ECtHR acknowledges that ‘the special feature of climate change as a common concern of humankind and the necessity of promoting intergenerational burden-sharing in this context […], speak in favour of recognising the standing of associations before the Court in climate-change cases’.[221] The Court sets three criteria for associations to have legal standing in climate change cases. The association in question must prove, firstly, that it is lawfully established; secondly, that it pursues a specific purpose in defending human rights in line with its statute; and, thirdly, that it is qualified to represent its members or other affected individuals.[222]

Importantly, the ECtHR separates the victim status of the members from the legal standing for associations, meaning that associations can have legal standing in climate change cases even if neither the association in question nor its members individually fulfil the criteria for victim status outlined above.[223] This distinction has been described as a ‘key innovation’.[224] On a more critical note, this result begs the question ‘who the victim is in this context’.[225] Similarly, Judge Eicke has argued in his Partly Concurring, Partly Dissenting Opinion that the majority has ‘created exactly what the judgment repeatedly asserts it wishes to avoid, namely a basis for actio popularis type complaints’.[226] Some voices in the literature have concurred with this opinion, claiming that ‘the Court has, for better or worse, created a “loophole” for associations in climate change cases allowing them to bypass all ordinary rules on victim-status’.[227] Similarly, other authors have argued that the ECtHR implicitly created an exemption to the necessity for victim status for associations in public interest litigation.[228] Others have maintained that the Court still sticks to the basic principle of avoiding actio popularis, while applying the victim status to future generations represented by associations.[229] Lastly, it has also been proposed to read the respective passage in KlimaSeniorinnen as not subjecting the associations members to the strict KlimaSeniorinnentest for victim status for individual applicants, but only to the ‘regular’ victim status test.[230]

In conclusion, the way in which the Court phrased this aspect seems to permit various interpretations on the issue of actio popularis. In the author’s opinion, it does not appear that this new rule would allow for actio popularis since the applicant association still has to fulfil the three criteria outlined above, which means that not just ‘anyone’ could bring a case before the ECtHR ‘without having been directly affected by it’. Indeed, in Fliegenschnee, the Court expressed doubts about the applicant organisation’s fulfilment of the second and third criteria since the organisation had not submitted any detailed information about its members or its statute to the Court.[231] In the end, the Court did not specify whether the association had legal standing since the case was ruled inadmissible for different reasons.[232] In any case, the ECtHR will need to further clarify this aspect in its future case law. 

In the KlimaSeniorinnen case, the ECtHR concludes that the applicant association has legal standing,[233] while the individual applicants have neither victim status nor legal standing.[234] The Court justifies the rejection of the victim status of the individual applicants by stating that the mere fact that ‘the applicants belong to a group which is particularly susceptible to the effects of climate change’[235] is not enough to grant victim status. Instead, it must be assessed for every single applicant ‘that the requirement of a particular level and severity of the adverse consequences affecting the applicant concerned is satisfied, including the applicants’ individual vulnerabilities which may give rise to a pressing need to ensure their individual protection.’[236] Thus, the Court applies the victim status for individual applicants rather restrictively, setting a high standard for the level of adverse consequences that affect them. This has been criticized in the literature as a flawed approach, ignoring the fact that victims, differently from the Plaumann test, must not be affected differently than all other people.[237]

In line with the distinction between environmental and climate law that the Court has maintained in KlimaSeniorinnen, in the Cannavacciuolo case concerning environmental pollution caused by the so-called ‘Terra dei Fuochi’ (‘Land of Fires’, i.e., areas affected by illegal dumping, burning, and burial of hazardous waste in Italy’s Campania region[238]), the ECtHR has held that the standing criteria for associations in climate cases established in KlimaSeniorinnen are not applicable to cases on environmental issues such as Cannavacciuolo.[239] Thus, the Court remains coherent with its logic advanced in KlimaSeniorinnen in arguing that climate change cases are fundamentally different from environmental cases.[240] However, Judges Krenc and Serghides have criticized this approach, expressing a ‘certain bewilderment’ at this argumentation.[241] Indeed, the distinction the ECtHR makes between climate and environmental cases could be seen as artificial and even counterproductive, also in light of the Reykjavik Declaration which addressed the ‘triple planetary crisis of pollution, climate change and loss of biodiversity’[242], as underlined by Judge Krenc and some voices in the literature.[243] Moreover, said distinction, on its flipside, seems problematic also regarding the possible application of the Aarhus Convention to climate cases, as the Court held in KlimaSeniorinnen.[244] Lastly, the impacts of large-scale environmental harm on future generations must also be taken into account in this regard.[245]

3.2.  Impact of KlimaSeniorinnen on Plaumann

3.2.1.   Interactions between the ECHR and the EU legal system

It has been said that with Carvalho, the CJEU ‘de facto excludes any possibility for climate change litigation under Article 263, paragraph 4, TFEU’, at least regarding framework cases.[246] It must be questioned whether this is still the case after KlimaSeniorinnen.

It has been observed in the literature that the ECtHR and the CJEU seem to be diametrically opposed: While the ECtHR shows itself open to the possibility of adopting a dynamic approach to the interpretation of the Convention in the face of the climate crisis, the CJEU seems set in its ways.[247] Thus, how can the KlimaSeniorinnen judgment influence the CJEU’s reasoning? Some authors have indeed argued that KlimaSeniorinnen must bring the CJEU ‘to make an exception for the “appropriate and tailored” remedy which that judgment constructed, exclusively in the sphere of climate change policy’.[248] This section analyses the potential impacts of the KlimaSeniorinnen judgment on the CJEU’s case law.

Naturally, the differences between the two legal systems must be borne in mind. Firstly, the CJEU and the ECtHR have different mandates.[249] Secondly, victim status under Article 34 ECHR cannot be understood synonymously to legal standing under Article 263, paragraph 4, TFEU. However, from a functional perspective, victim status and individual concern serve a similar purpose, i.e., preventing actio popularis.[250]

The CJEU has repeatedly held that ‘the ECHR does not constitute, as long as the European Union has not acceded to it, a legal instrument which has been formally incorporated into EU law’.[251] Nonetheless, while being separate legal systems (for the time being), the EU legal system is connected to the ECHR through different provisions of primary law, i.e., Article 6, paragraphs 2 and 3, TEU and Articles 52 and 53 CFR.[252] Furthermore, long before the adoption of the Charter, the ECtHR’s jurisprudence was a fundamental source of interpretation in shaping general principles of EU law regarding fundamental rights protection.[253] Today, Article 6, paragraph 3, TEU establishes that the human rights guaranteed by the ECHR serve as general principles of European law.[254] Therefore, it seems plausible, necessary even, to query if and how the landmark ruling by the ECtHR might influence the CJEU regarding its approach to the prevention of actio popularis.

Against this backdrop, it must be analysed how ECtHR judgments can influence the CJEU’s jurisprudence. Article 52, paragraph 3, CFR, the so-called ‘consistency clause’,[255] requires the Charter rights to be interpreted consistently with their respective ECHR counterparts.[256] Consequently, through the consistency clause, the CJEU has replicated the ECtHR’s ambitious jurisprudence on different occasions in the past, for instance in the field of data protection. In Digital Rights Ireland, the CJEU relied heavily on the Marper judgment by the ECtHR in order to establish a more stringent approach to data protection.[257] In addition, the CJEU’s jurisprudence on migration has been heavily influenced by the ECtHR’s jurisprudence. For example, in Abdida, the CJEU referenced the ECtHR’s jurisprudence on expulsions.[258] Moreover, Article 52, paragraph 3, CFR, together with Article 53 CFR, establishes that the ECHR serves as a minimum level of protection.[259] In this regard, it has been argued that these norms require the CJEU to adopt an interpretation in conformity with the KlimaSeniorinnen ruling.[260] It must be noted that this observation applies to corresponding fundamental rights, not procedural requirements. 

When it comes to legal standing, a direct influence in the sense of a legal obligation for the CJEU to mirror the ECtHR’s view on legal standing seems difficult to construe. Article 52, paragraph 3, CFR concerns the interpretation only of CFR rights, not of all sources of EU primary law.[261] Hence, this provision does not directly apply to the interpretation of TFEU provisions such as Article 263, paragraph 4, TFEU. However, one could imagine the following detour: As a first step, Article 47 CFR must be interpreted in light of Article 6 ECHR through Article 52, paragraph 3, CFR.[262] As a second step, Article 263, paragraph 4, TFEU must respect Article 47 CFR.[263] Thus, one could take into consideration that the CJEU would have to ‘indirectly’ interpret Article 263, paragraph 4, TFEU in light of the ECtHR’s interpretation of Article 6, paragraph 1, ECHR. As discussed above, the CJEU’s restrictive approach to legal standing seems to be at odds with Article 47 CFR and Article 9, paragraph 3, Aarhus Convention. Thus, this indirect influence of Article 6 ECHR on the interpretation of Article 263, paragraph 4, TFEU could strengthen this argument. In practice, however, as noted above, the CJEU has continuously held that Article 47 CFR cannot change the standing requirements set out in the Treaties.[264] In addition, the ECtHR’s ruling on Article 6 concerned the access to domestic courts, not to the ECtHR.[265] Thus, it would be difficult to transpose this line of argumentation to access to the CJEU, especially as this would only prompt the CJEU to repeat the well-known ‘complete system of legal remedies’ argument. Therefore, this argumentation would have little practical impact. 

In any case, the CJEU would be required to consider the ECtHR’s interpretation of Article 8 ECHR when assessing the merits of climate litigation cases if applicants rely on Article 7 CFR.[266] Naturally, this would only be the case if such a case were found to be admissible.

In the recent Asociația Inițiativa pentru Justiție case, which in substance concerns the rule of law, the General Court has directly analysed the applicant’s claim that the approach used by the ECtHR in KlimaSeniorinnen ‘should apply mutatis mutandis in the present case’.[267] In response to this claim, at the outset, the GC repeats three well-known arguments against the widening of legal standing for individual applicants. Firstly, there must not be any interpretation of standing requirements which effectively undermines the conditions set out by the TFEU.[268] Secondly, the Court reiterates that Article 47 CFR cannot amend the system of judicial review enshrined in the Treaties and does not grant unconditional access to EU courts to individuals.[269] Thirdly, the Court refers to the ‘complete system of legal remedies’.[270]

Regarding the question of applying the ECtHR’s approach to Article 6, paragraph 1, ECHR in KlimaSeniorinnen to the present case, the GC held that 

‘it is sufficient to recall that whilst, as Article 6(3) TEU confirms, fundamental rights recognised by the ECHR constitute general principles of EU law and whilst Article 52(3) of the Charter provides that the rights contained in the Charter which correspond to rights guaranteed by the ECHR are to have the same meaning and scope as those laid down by the ECHR, the latter does not constitute, for as long as the European Union has not acceded to it, a legal instrument which has been formally incorporated into EU law’.[271]

The GC concludes on this point that ‘an easing of the conditions of admissibility, as sought by the applicant, would in fact mean setting aside the condition of direct concern expressly laid down in the fourth paragraph of Article 263 TFEU’.[272]

Interestingly, the Court seems to blend a question of substantial law (the ECtHR’s interpretation of Article 6 ECHR) with the question of admissibility. As outlined above, Article 6 ECHR cannot have a direct impact on the standing criteria under Article 263, paragraph 4, TFEU since Article 52, paragraph 3, CFR does not apply between the ECHR and procedural norms of the TFEU. Perhaps, it would have been more convincing to maintain a clearer differentiation between procedural and substantive law. The Court could, firstly, have assessed the interpretation of Article 47 CFR in light of the ECtHR’s interpretation of Article 6 ECHR under Article 52, paragraph 3, CFR. As a second step, the Court could have assessed the interplay of Article 47 CFR with Article 263, paragraph 4, TFEU in this case. However, Court has already mentioned before that Article 47 CFR does not change its interpretation of the standing criteria under Article 263, paragraph 4, TFEU in order not to rob this provision of its meaning. In the author’s view, such a two-fold structure would have made the Court’s reasoning easier to follow instead of blurring the lines between admissibility and merits. The appeal against this order is currently pending before the CJ.[273] It will be crucial to see how the CJ will address this line of argument.

Furthermore, it remains questionable which legal consequences the EU Member States might face under their ECHR obligations after KlimaSeniorinnen if the CJEU continues to apply the Plaumann test. In fact, it has been argued that ‘if the ECJ sticks to its restrictive position on access to justice for associations before EU courts, EU membership may expose Member States to the risk of being held responsible in Strasbourg’ under the Bosphorus[274] doctrine.[275] In other words, EU Member States might still be responsible under the ECHR and subject to the ECtHR’s full review of national climate plans regarding effective protection of fundamental rights, should the ECtHR find that the EU’s level of protection is not equivalent to that under the ECHR.[276] The future of said doctrine after the accession of the EU to the ECHR appears uncertain, however.[277]

Lastly, the ruling could produce indirect impacts[278] insofar as it could influence the European and even global legal culture, which has been dubbed the ‘KlimaSeniorinnen revolution’.[279] In fact, the judgment constitutes a ‘significant milestone for climate litigation’ globally.[280] The main takeaway from KlimaSeniorinnen for the CJEU should be that legal standing in climate litigation cases requires a novel approach to the concept of legal standing itself, an adaption of the traditional criteria to an unprecedented situation: the climate crisis. In addition, the fact that the CJEU judges are very familiar with the ECtHR’s jurisprudence might lead to a cross-fertilisation across jurisdictions regarding legal standing.[281] This can be traced back to the concept of judicial comfort, according to which progressive decisions from different courts can lead to a ‘sense of safety and support that judges derive from seeing other judges taking new interpretative steps, leading a judge to diverge from the established case law on a given subject matter’.[282]

In conclusion, there are various ways in which the KlimaSeniorinnen judgment could potentially influence the CJEU’s approach to legal standing for individual applicants. It is notable that the judgment has so far been cited by applicants not in climate litigation, but rule of law cases, i.e., Medel and Asociația Inițiativa pentru Justiție. After the ruling of the GC in the latter case, a direct impact does not seem very likely, at least until the EU’s accession to the ECHR. Nonetheless, the Court still has the opportunity to reverse the ruling on appeal.

3.2.2.   Revisiting Plaumann

Adopting a constructive approach, the strong criticism of Plaumann and the radically new approach of the ECtHR in KlimaSeniorinnen beg the question which understanding of legal standing for individual applicants could potentially replace the Plaumann test. This section strives to critically evaluate different suggestions, both old and new, with specific regard to their applicability in climate litigation cases.

Firstly, in 2023, the European Parliament had proposed to scrap the requirement of ‘individual concern’ altogether.[283]Currently, it seems unlikely that the Member States will accept this radical proposal.[284] Nonetheless, this process should be closely monitored.

Secondly, as mentioned in section 2.1, AG Jacobs has proposed in his Opinion in UPA that ‘an applicant is individually concerned by a [Union] […] measure where the measure has, or is liable to have, a substantial adverse effect on his interests’.[285]However, this criterion might be too broad when applied to climate change litigation cases since climate change unarguably has a substantial adverse effect on the interests of any person to a certain extent, as recognized by the ECtHR. Moreover, as laid out above, the Court has already rejected this proposal.

Thirdly, the GC[286] had ruled in its judgment in Jégo-Quéré, later overturned by the Court of Justice, that ‘a natural or legal person is to be regarded as individually concerned by a [Union] […] measure of general application that concerns him directly if the measure in question affects his legal position, in a manner which is both definite and immediate, by restricting his rights or by imposing obligations on him’.[287] It has been argued in the literature that this interpretation stays within the textual limits of Article 263, paragraph 4 TFEU, constituting merely ‘a new way of interpreting the Treaty-based condition for individual concern’.[288]Nonetheless, this approach does not seem to be apt to deal with climate cases since it would be very difficult to prove that an EU legal act affects the applicant’s legal position in a manner which is both definite and immediate, since the effects of (unsatisfactory) climate legislation will only show over time.[289] Moreover, this approach seems slightly overbroad as well. Lastly, as laid out above, the Court has already rejected this proposal on appeal.

Fourthly, some have proposed to assume individual concern where fundamental or subjective rights might be violated.[290] This option seems overbroad and unrealistic whilst also ignoring the division of labour between the CJEU and national courts.[291] It has been argued that for such an interpretation, which is inspired by the German Verfassungsbeschwerde, a Treaty change would indeed be necessary.[292] In fact, such an interpretation would go beyond the character of the annulment procedure.[293]

Fifthly, as mentioned in the introduction, AG Emiliou’s recent Opinion in Nicoventures makes a case for a revisitation of the Plaumann case law, without abandoning Plaumann altogether.[294]

Generally, AG Emiliou argues that the Plaumann test fits the criterion of individual concern from a textual, historical, and systematic perspective.[295] Regarding the textual interpretation, he argues that the term ‘individual’ strongly implies that ‘the greater the number of the persons alleging a special effect, the less likely that they can all be considered to be “individually concerned”’.[296]Concerning the systematic and the historical interpretation, in essence, he repeats two well-known arguments: Firstly, he argues that the Member States did not and do not want to broaden legal standing for individuals, as can be seen from the drafting processes of the Treaties and of the European Constitution.[297] Secondly, he relies on the argument of the complete system of remedies and the division of labour between the CJEU and national courts concerning direct and indirect actions,[298] which has been discussed above.

However, AG Emiliou proposes three key changes to the Court’s case law.[299] Firstly, the AG calls for a systematisation and categorisation of the case law. He argues that the Court should issue a landmark judgment in the interest of legal clarity to ‘offer a coherent and exhaustive framework’ of the criterion of individual concern.[300] Secondly, the AG highlights the need for a refinement of the closed-group test. He makes a case for abandoning the so-called ‘future element’.[301] This ‘future element’ means that the ‘EU Courts required (or appeared to require) that the category of persons particularly affected by the contested measure, to which the applicant alleges to belong, is composed of a fixed number of persons that cannot be enlarged after the adoption of the contested measure’.[302] In his Opinion, the AG proposes opening the case law of the Court to the possibility of enlarging a closed group after the adoption of the measure in question.[303] Thirdly, the AG underlines the need for the ‘equivalent treatment of all persons in respect of all rights’.[304] He observes that the Plaumann criteria have been ‘applied more rigorously at times and more leniently at others, in cases that – at least when viewed with today’s eyes – are largely similar’, see the discussion on the ‘double standard’ of the CJEU’s application of Plaumann above (section 2.2.1.).[305] Consequently, according to the AG, ‘(i) non-profit entities (such as associations and non-governmental organisations) should generally be considered by the same standards applied to profit-making entities (such as companies), and (ii) it should be of no relevance whether the applicants’ rights or interests affected by the contested measures are of an economic nature or of a different nature’.[306]

The proposal by AG Emiliou marks a turning point, as it is the first AG Opinion in years to examine the Plaumann case law in such depth.[307] Regarding climate litigation, the last of the three proposals seems to be the most relevant. As has been shown above, the Court seems to apply a ‘double standard’ regarding companies versus non-profit organisations, or rather, economic versus non-economic interests. The shift proposed by the AG would be a major step towards creating a level playing field for applicants in environmental and climate litigation before the CJEU. However, it is questionable whether the changes proposed by AG Emiliou are far-reaching enough to adequately ensure access to justice for individuals in environmental and climate litigation cases. At the end of the day, AG Emiliou still defends the Plaumann test with the well-known arguments of the unwillingness of the Member States to amend the Treaties and of the complete system of remedies. Therefore, framework cases as Carvalho would likely still not be admissible under AG Emiliou’s framework. Nonetheless, this proposal generally seems to have a better chance at being accepted by the Court in the long run, as it is less radical than previous attempts by AG Jacobs and the GC in UPA and Jégo Quéré.[308]Consequently, it is a laudable step in the right direction.[309]

However, the Court did not follow AG Emiliou’s tripartite suggestion on systemizing the case law on Plaumann.[310] Instead, it only provided deeper insights into the definition of acquired rights.[311] Thus, the Court responded only to the second of the three reform proposals put forward by AG Emiliou, namely the call for abandoning the ‘future element’. In this regard, the Court specified that acquired rights require a two-step test, namely, firstly, the applicant being identified or identifiable at the time of the adoption of the measure and, secondly, that the applicant in question possesses ‘specific characteristics in comparison with other persons to whom that act is intended to apply’.[312] Moreover, the mere ‘fact that the marketing authorisations at issue were non-exclusive […] can have no bearing on the ability to distinguish the appellants individually’.[313] This refinement can be seen as a ‘partial response’ to AG Emiliou’s reform proposals.[314] However, this clarification is rather tame, certainly not as innovative as the AG Opinion.[315]

Sixthly, Winter has proposed a substantial approach to individual concern in which individual concern is defined as the material criterion of ‘personal and severe concern’,[316] taking into account factors such as ‘degrees of harm (superficial, serious, lasting, reversible, etc.), legitimate expectations (vested interests vs newcomers), cognition (degree of certainty of harm), causality (cause – effect – intervening factors), and time (imminent vs future interference)’.[317] AG Emiliou has pointed out that this test partly resembles the approaches of AG Jacobs in UPA and of the GC in Jégo Quéré.[318] In addition, this approach seems to be similar to the first limb of the two-prong test adopted by the ECtHR in KlimaSeniorinnen for individual applicants (‘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’) since both tests rely on severity/intensity. It must be queried whether this approach could be transferred to a new interpretation of individual concern for individual applicants under Article 263, paragraph 4, TFEU in climate litigation cases. It has been stated that individual concern has nothing to do with the intensity of rights violations.[319] While this might hold true for the past CJEU case law, there seems to be no logical reason why individual concern as a category should not be understood in terms of intensity, particularly if the CJEU should decide to revisit Plaumann.[320] Furthermore, the ECtHR shows in KlimaSeniorinnen that adopting a new understanding of legal standing in climate cases does not necessarily lead to the admission of any type of climate-related claims, as it rejected legal standing for the individual applicants in the case in question.[321]

Therefore, the criteria that the ECHR adopts, both regarding individual applicants as well as associations, could serve as a source of inspiration for the CJEU. Individual concern could be interpreted in the sense that individual applicants must prove, firstly, to be ‘[…] subject to a high intensity of exposure to the adverse effects of climate change […]’.[322] Indeed, it seems plausible that a person is individually concerned by an act if said act affects said person on a significantly higher scale than it affects other people. This is especially important for the phenomenon of climate change, since it will never affect only a ‘closed group of people’.[323]Instead, it will affect everyone to some extent, as the ECtHR pointed out. Thus, at least regarding climate change, intensity seems to be the only way to establish individual concern. Admittedly, this is an innovative proposal, but, in the author’s opinion, it would be possible to interpret individual concern in such a manner.

In Winter’s approach, the second part of the ECtHR’s test (‘pressing need to ensure the applicant’s individual protection, owing to the absence or inadequacy of any reasonable measures’) seems to be missing. It appears most convincing if the CJEU mirrored the two-step test adopted by the ECtHR to establish individual concern in climate litigation cases: firstly, a substantive test of the degree of harm to the applicant, relying on the criteria established by the ECtHR in KlimaSeniorinnen or the criteria proposed by Winter; secondly, a ‘subsidiarity test’, mirroring the second prong of the test in KlimaSeniorinnen. In this second part of the test, the CJEU could evaluate whether in the case at hand other procedures are available to the applicants under EU law. The difficulty for this second step is that the CJEU cannot assess other available remedies under national law since the CJEU does not have the competence to interpret Member States’ procedural law.[324] This theoretical and practical hurdle seems to be difficult to overcome. However, a solution to this issue could be sought. For instance, one could establish that the parties would have to provide an expert opinion from a legal professional from the respective Member State as part of their application.

Even more importantly, the CJEU should follow the ECtHR in accepting that associations are of particular importance in climate litigation and should not be subject to overly restrictive standing criteria.[325] Under the current case law, the CJEU would likely not be able to accept legal standing for associations whose members are not themselves individually concerned under Plaumann since the second category established by the case law requires that ‘the association represents the interests of its members, who would themselves be entitled to bring proceedings’. However, the ECtHR has convincingly shown that the victim status, or in the case of EU law, individual concern, of the members of the association does not necessarily have to be the precondition for recognizing the legal standing of the association. Naturally, this approach may theoretically bear the risk of many associations being able to instigate annulment procedures before the Court. However, if applied carefully and confined to climate cases, this does not necessarily have to lead to actio popularis. Instead, broadening legal standing for associations could, at least to some extent, ease the Plaumann paradox.[326] In order to prevent abuse, i.e., individuals creating associations for the sole purpose of initiating an annulment procedure, and, again, actio popularis,[327] the Court could rely on the criteria for associations set forth in KlimaSeniorinnen.[328] Lastly, relying on associations bringing cases before the CJEU instead of individuals could help in ‘streamlining litigation’.[329]

All things considered, the Court should, as a bare minimum, implement the changes proposed by AG Emiliou in Nicoventures in its case law. These changes, especially the third proposal, would already be a crucial improvement for the legal standing of environmental NGOs. However, as outlined above, the Court, for the time being, has not followed this proposal in its ruling in Nicoventures. It remains to be seen if the Court will be more open to change in its future case law, e.g., in the appeal ruling in the case Asociația Inițiativa pentru Justiție. In addition, it would be auspicial that the Court adopt a tailored approach to legal standing for individuals and associations in climate litigation, even though this more ambitious proposal appears to be even less realistic for the time being.

4.   Conclusion

In conclusion, the ECtHR’s progressive approach in KlimaSeniorinnen could serve as an example for the CJEU’s case law regarding legal standing for individuals under Article 263, paragraph 4, TFEU. As has been shown in this article, it is high time for the CJEU to reconsider the traditional Plaumann criteria for defining ‘individual concern’, at least in part, and to adapt it to the current phase of European integration in the 21^st century. This revision is especially important for climate litigation, as highlighted above, since individual applicants and associations are functionally excluded from bringing annulment procedures before the CJEU in framework cases. The Court should ‘overrule’ this test developed in its case law – or, at the very least, apply it more coherently and fairly, as suggested by AG Emiliou in Nicoventures. On the one hand, it still seems questionable whether the CJEU will ever cease its static approach since it has consistently resisted the strong criticism of the Plaumann criteria by both AG Jacobs and the literature. However, the KlimaSeniorinnen judgment is a development in European legal culture which cannot be ignored. 

The suggested avenue in this contribution is to interpret individual concern in climate litigation as a two-prong test for individual applicants and to broaden the standing for associations, drawing inspiration from the approach in KlimaSeniorinnen. While such a change might seem ambitious,[330] it would arguably be the only way to effectively ensure access to justice in climate litigation relating to EU climate targets. Naturally, sector-specific solutions are difficult to justify, but in this area the principles of access to justice and effective judicial protection require such a step.

It remains to be seen if either the ‘revolutionary’ ruling by the ECtHR in KlimaSeniorinnen or the more diplomatic proposal by AG Emiliou in Nicoventures will lead to a change in the CJEU’s approach. As shown in this article, the pending rulings in Medel and Asociația Inițiativa pentru Justiție provide the CJEU with the opportunity to revise and refine its case law regarding legal standing of individuals and associations. However, arguing for such change might be little more than an idle hope.

In any case, all procedural avenues available in the EU legal order should be explored in order to nurture a better understanding of which role the CJEU can play in European and global climate change litigation.[331] It remains an open question whether Article 263, paragraph 4, TFEU is the most promising procedural avenue for climate change litigation under EU law, with or without Plaumann. The two-month deadline after the publication of the acts of EU climate legislation envisaged by Article 263, paragraph 6, TFEU is rather restrictive.[332] Thus, in addition to being limited in personal scope, there is also a temporary restriction. In the case of climate change litigation, ‘the fact that EU action is inadequate may only become apparent with time, as the intensity of the climate emergency manifests itself.’[333] Therefore, Article 263, paragraph 4, TFEU might not be a ‘one fits all’ solution for climate litigation before the CJEU. Future research should therefore continue to explore the potential impacts of preliminary rulings in climate change litigation[334], even though this avenue has its pitfalls, as analysed above, as well as of other procedural avenues, such as infringement procedures, actions for failure to act, and non-contractual liability of the Union.

In summary, the analysis of the role of the CJEU in climate litigation through the annulment procedure and other procedures requires continued research efforts. The future will show whether the CJEU will choose to follow the ECtHR’s way and embrace an innovative approach to legal standing for individual applicants in climate litigation or if it will continue to adhere to the restrictive approach of the Plaumann test. After KlimaSeniorinnen and the Opinion by AG Emiliou in Nicoventures, it seems that in the next framework climate litigation case the CJEU would have to at least address these recent developments. However, the outcome remains uncertain: One could argue that we are in a ‘now or never’ situation regarding the overruling of Plaumann.