A. Introduction
The climate emergency is unfolding.Footnote 1 Despite the universal political recognition that global warming needs to be halted below an increase of 1.5°C compared to pre-industrial levels,Footnote 2 a consistently large gap exists between the actions of states and the global emission reductions necessary in order to achieve that target.Footnote 3 Actions of the European Union and the Member States also fall short. The Climate Action Tracker, an independent scientific project that tracks countries’ mitigation efforts towards meeting the Paris Agreement temperature limit, rates the efforts of the EU as “insufficient.”Footnote 4 In light of this public institutional failure, civil society actors increasingly resort to strategic climate litigation.Footnote 5 However, the EU has very restrictive standing requirements for direct actions against general acts. Therefore, most strategic climate litigation is brought to national courts. In 2023 and 2024, national judges have in several cases allowed defendant states—to different degrees—to use EU law as a shield against the litigants’ demands to declare national climate policy insufficient. Illustrative examples are the rulings of the Spanish Supreme Court of July 2023—Greenpeace vs Spain I and II Footnote 6—the Czech Supreme Administrative Court of February 2023—Klimatická žaloba ČR Footnote 7—and the Italian Court of First Instance in Romein February 2024—the A Sud case.Footnote 8 In addition, the Court of Appeal in Klimaatzaak, decided in Belgium in November 2023, while explicitly holding that the state could not hide behind EU law, was strongly influenced by the EU target in its substantive review.Footnote 9 In all of these cases, the defendant states argued that EU law was an obstacle to challenging national climate action in national courts in light of other legal obligations, such as tort law and human rights, including as they are guaranteed under the European Convention on Human Rights (ECHR).
This Article concludes that in light of the fact that EU climate policy is inadequate and nearly impossible to challenge, it is highly problematic when national judges accept EU law to be an obstacle to full judicial review. First, EU law itself does not require national judges to interpret EU law as an obstacle to judicial review of national climate policy. While political and also legal tensions may arise when national courts declare EU-compatible national mitigation action insufficient and unlawful such tensions do not amount to a doctrinal legal argument that EU law sets aside all other legal obligations of Member States. Second, the ECHR, read in light of KlimaSeniorinnen, imposes higher requirements on Member States than EU law. Third, the European Court of Human Rights (ECtHR) would not accept, in the context of climate mitigation, the “EU law as a shield” argument, protecting Member States from responsibilities under the ECHR. As such, Member States do not face responsibility under EU law, when national judges review national climate policies; however, they may face responsibility under the ECHR, when national judges fail to do so. In addition, closing down the judicial avenues for demanding justification for inadequate climate policies, not only in the EU Courts but also in national courts, is problematic from a democratic and separation of powers perspective.
The term “strategic climate litigation” is here used in line with the introductory article’s definition of strategic litigation as “legal action initiated to achieve broader social, political, or economic ends” for litigation against EU Member States challenging the sufficiency and hence lawfulness of national climate policy.Footnote 10 In line with this Special Issue’s focus on EU law, this Article focuses on those cases and parts of judicial reasoning that engage with EU law. It does not consider litigation against companies that does not directly challenge public policy, narrower sectorial litigation against specific measures, “non-strategic” litigation that primarily serves the interest of the litigant without “exert[ing] influence over policies and political processes,”Footnote 11 or litigation against states that are not Member States of the EU. This Article aims to contribute to the second dimension highlighted by the analytical framework of this special issue, namely “the specific legal structures of EU law” and how they “determine the legal conditions for strategic litigation” in Europe.Footnote 12 The Article adds to the doctrinal debates surrounding the interaction of legal layers within the EU’s multilayered legal landscape, examining the relations and interactions between: National, human rights and tort; international, United National Framework Convention on Climate Change (UNFCCC), Paris Agreement, and ECHR; and supranational/regional law, such as EU law. The judgment of the ECtHR in KlimaSeniorinnen of April 9, 2024 raises new questions about the Member States’ climate obligations under the ECHR.Footnote 13
While this Article does not necessarily reveal the ambivalence of strategic litigation,Footnote 14 it speaks to the ambivalence of EU law in strategic litigation in the field of climate change. It proposes that, while EU law seems prima facie empowered when courts decline jurisdiction or limit their review because of EU law, ultimately, this level of deference of national courts, in combination with the strictly limited possibilities to challenge judicially EU climate policy before the European Court of Justice (ECJ), closes off necessary channels for disagreeing and demanding further justification. These avenues are part of modern democracies based on the rule of law and separation of powers. Closing off channels for judicial contestation entirely weakens the democratic legitimacy of the EU’s and the Member States’ climate policy.
Section B sets out the EU’s role in adopting climate mitigation policies. The EU is competent to adopt comprehensive climate policies—Section B.I.—and does so—Section B.II. Yet, because of the way the EU legal order is set up, it is excessively difficult to challenge EU climate targets and policies—Section B.III. This makes it all the more relevant whether the targets and emission reduction plans adopted by the EU can protect Member States from legal challenges brought before national courts, in other words act as a “shield.” Section C discusses what role international legal norms play in the relationship between the EU and the Member States. It focuses on the UNFCCC, the Paris Agreement, and the ECHR. Section D addresses the main research question of whether and how membership in the EU frames national judges’ ability to review national climate targets and policies. Section D.I. examines strategic climate litigation in Europe as to the judges’ position on the role of EU law as an obstacle to judicial review. Section D.II. sets out why EU law cannot be a shield against other legal obligations and does not stand in the way of judicial review by national courts. Section E concludes.
B. Preliminary Note on EU Law
The EU has extensive powers to adopt climate and environmental policies—Section B.I.—which are then binding on the EU Member States and enjoy, as a matter of principle, primacy over national law. The EU has also de facto adopted a wide range of climate-related measures, for example in the context of the European Green Deal—Section B.II. At the same time, EU climate policies are difficult to challenge—Section B.III. Much has been written about the overly stringent interpretation in the Plaumann line of case law on the standing of individuals under now-Article 263(4) TFEU.Footnote 15 This limitation, if anything, becomes particularly apparent in the context of climate change which affects everyone in some way. In short, EU law sets mitigation standards that are difficult to challenge in court, while as we will see, they fall short of what the EU needs to do to mitigate climate change.
I. Competence Division in Climate Matters
Law-making in the EU is framed by the applicable legal basis. Pursuant to Articles 191–193 TFEU, the EU may legislate on environmental and climate matters. This is a shared competence, which means that Member States can only enact rules if the EU has not already exercised its powers or has explicitly relinquished them, otherwise the Member States are pre-empted from adopting national measures.Footnote 16
However, EU primary and secondary law expressly allow Member States to adopt and implement more ambitious climate mitigation targets and policies than those required under EU law. The EU adopts measures based on 192 TFEU pursuing the Treaty objectives set out in 191 TFEU. Article 193 TFEU stipulates that “measures adopted pursuant to Article 192 shall not prevent any Member State from maintaining or introducing more stringent protective measures. Such measures must be compatible with the Treaties.” The general rule of pre-emption, pursuant to which Member States can no longer act when the EU has regulated a specific issue or occupied a regulatory field, is hence modified. Secondary law confirms Member States’ competence to adopt more stringent climate policy by imposing minimum harmonization. Examples are the European Climate Law and the Effort Sharing Regulation (ESR), which speaks of an obligation to “limit its greenhouse gas emissions at least by the percentage set for that Member State.”Footnote 17 The ECJ confirmed that Member States may not only set higher standards in the context of minimum harmonization but that these higher standards fall outside the scope of EU law.Footnote 18
II. EU Climate Targets and Policies
The EU set a binding target of climate neutrality for 2050 and a net GHG emission reduction target for 2030 of 55% compared to 1990.Footnote 19 It is in the process of adopting a binding target for 2040.Footnote 20 For the execution of these targets, it defers to the Member States through the adoption of National Energy and Climate Plans (NECPs) setting out how they plan to realize the targets.Footnote 21 The NECPs in turn require further implementation, ultimately coming down to decisions on individual projects, authorizations, and sector targets.
Fourteen of the twenty-seven EU Member States have net zero targets by 2050 or earlier enshrined in national law.Footnote 22 Eight further Member States have committed to net zero in 2050 in policy declarations.Footnote 23 Again, two others have made a pledge in this respect and two are in the process of taking an official position.Footnote 24 One Member State has not taken any official position.Footnote 25 The ESR emphasizes the importance of fairness, understood as taking into account the different capacities of Member States by differentiating targets according to Gross Domestic Product (GDP) per capita and then adjusting targets to reflect cost-effectiveness for those Member States with an above average GDP per capita, and solidarity among Member States.Footnote 26 It also offers flexibility mechanisms.Footnote 27 The 2023 EU ESR increases the emission reduction target for the covered sectors from 29% to 40% by 2030, compared to 2005 levels.Footnote 28 The ESR accounts for nearly 60% of EU GHG emissions.Footnote 29 The remaining emission fall under the market-based mechanism of the Emission Trading System (ETS) Directive and the Land Use, Land Change and Forestry (LULUCF) Regulation.Footnote 30 The EU also adopts specific sectorial policies that pursue the aim to reduce CO2 emissions, such as performance standards for passenger cars.Footnote 31
III. Challenging the Legality of the EU’s Climate Policies
EU climate targets and policies have been challenged several times before the ECJ. The most well-known climate case before the ECJ is the case of Carvalho, also called the People’s Climate Case—a direct action that failed on the EU’s restrictive standing requirements for individuals, including associations.Footnote 32 The next subsection—Section B.III.1—engages with the substance of these challenges, concluding that indeed the EU’s climate targets and policies fall short what is needed to stay below the 1.5°C temperature limit. The following two subsections set out the difficulties to challenge EU climate targets and policies before the ECJ in direct—Section B.III.2—and indirect—Section B.III.3—actions, respectively.
1. EU Climate Targets and Policies Are Incompatible with 1.5°C
EU target and policies are insufficient to keep global warming below the long-term temperature limit of 1.5°C as enshrined in the 2015 Paris AgreementFootnote 33 The IPCC reports on emission reduction pathways that if followed provide a certain likelihood of remaining below different temperature levels. According to the IPCC, to maintain a 50% chance of holding temperatures below 1.5°C, global emissions need to be reduced by 43% by 2030 compared to 2019 levels.Footnote 34 The EU is not meeting this necessary reduction level. According to the independent scientific institute Climate Analytics, the EU would need to reduce its emission by 66% by 2030 compared to its 1990 levels in order to stay on the IPCC global pathway.Footnote 35
The IPCC global pathways, however, are an inappropriate standard by which to determine the sufficiency of the EU’s efforts in staying below the 1.5°C temperature limit. The UNFCCC and the Paris Agreement establish as a central guiding principle of distribution of efforts the principle of Common But Differentiated Responsibilities and Respective Capabilities (CBDR-RC).Footnote 36 Other guiding normative principles that are relevant for assessing countries’ climate ambitions are the precautionary principle, the principle of progression, and the ‘highest possible ambition’.Footnote 37 While these principles necessarily require further concretization, they are legally binding and establish unambiguously that those Contracting Parties with high responsibility for the accumulation of emissions in the atmosphere and high economic and technical capabilities, have a higher responsibility to ensure the necessary emission reductions.Footnote 38 IPCC pathways, however, are generally based on global cost efficiency considerations and do not take into account equity considerations as is required by the principle of CBDR-RC.Footnote 39 In other words, determining the fairness of EU and national efforts as a sufficient contribution to the collective efforts of all states necessary to achieve the 1.5°C temperature limit does not flow from the scientific information alone but requires a normative—legal—assessment on compatibility with international and domestic law.
In a 2021 article, leading scholars on law and climate science quantified the fair share responsibilities of states based on a principled reasoning rooted in international law.Footnote 40 Based on this assessment, the EU’s fair share responsibility for remaining below the 1.5°C temperature limit would be to reduce emissions to a level of 111% below its 2010 levels by 2030.Footnote 41 This means that by 2030, the EU will have used up its fair share of emissions space and need to achieve “net-negative” emissions of 11%. According to the study, “[i]f such a level is not reachable with domestic emission reductions, these states will need to correspondingly scale up the support they offer to others to reduce their emissions, based on the principle of cooperation.”Footnote 42
The Carvalho case, which predates the aforesaid study, used a comparable fair share analysis to show the insufficiency of EU targets.Footnote 43 Also, similar to the evidence used in KlimaSeniorinnen,Footnote 44 the plaintiffs put forward different methodologies for determining the fair share of the remaining global carbon budget, each of which would require emission reductions that lie far beyond the EU targets.
The challenge that the EU’s climate policy does not meet the standard of fairness has further been confirmed by the European Scientific Advisory Board on Climate Change (ESABCC), established under the European Climate Law with the aim to advise the EU on how to take the necessary measures towards climate neutrality.Footnote 45 In its 2023 report, the ESABCC addressed the question of what the EU’s reduction target for 2040 should be.Footnote 46 It set out a two-pronged assessment. First, it determines the EU’s fair share carbon budget for 1.5°C in light of the discussed equity principles of international law, concluding that under certain fairness considerations, the EU’s fair share budget is already exhausted.Footnote 47 Second, it assessed the feasibility of pathways for reducing emissions within the EU’s territory. On the basis of this assessment, it recommends an EU reduction target for 2040 of 90-95% compared to 1990.Footnote 48 However, based on the preceding fairness considerations, the ESABCC also highlights that “none of the assessed pathways towards climate neutrality fully align with the fair share estimates, additional measures need to be pursued to account for this shortfall.”Footnote 49 Therefore, “[a]mbitious domestic reductions need to be complemented by measures outside the EU to achieve a fair contribution to climate change mitigation.”Footnote 50 In this context the ESAB notes that increasing the 2030 target from 55% to 70% or more would “increase the fairness of the EU’s contribution to global mitigation.”Footnote 51
2. Direct Challenges
The ability of natural and legal persons to challenge EU legal acts is framed by the procedural rules under the Treaties. If a person has suffered harm due to the actions or inaction of an EU institution, they may bring a case directly to the General Court under the requirements of Article 263(4) TFEU.Footnote 52 This is the “default tool for strategic litigation.”Footnote 53 Article 263(4) TFEU grants legal standing to persons and, in an even more limited fashion, associations to challenge three different EU acts: acts addressed to the applicant (first option); regulatory acts, executive acts of a general nature, that are of direct concern to them and do not involve further implementation, (third option); and other legal acts if the applicant is directly and individually concerned (second option). Many scholars have criticized the standing rules for direct actions against other legal acts as too restrictive, in particular in the context of environmental harm.Footnote 54
In particular, the requirement of distinctiveness, in other words, that applicants need to demonstrate that they are uniquely affected, maintained by the ECJ, while being far from clearly defined, has been widely criticized as overly formal and “paradoxically denying legal protection when harm is serious and wide-spread,” as is precisely the case in the context of the climate emergency.Footnote 55
The ECJ also takes a restrictive approach to access to justice of, especially environmental, associations.Footnote 56 Traditionally, associations have only been able to challenge EU acts after having been granted a specific prerogative or procedural right in prior decision-making procedures.Footnote 57 Associations do not meet standing requirements to challenge EU acts that affect collective interests.Footnote 58 Among other things, the ECJ makes standing of association depend on the members of the association meeting the standing requirements.Footnote 59
Several European cities—infra-state entities—brought legal challenges against Commission acts implementing EU climate laws,Footnote 60 motivated by the intention to strengthen climate action. The Cities argued that the Commission acts, allowing for higher emissions than the legislation they implemented, directly affected their powers concerning air quality and traffic regulation.Footnote 61 The ECJ disagreed. It confirmed that infra-state entities must meet the same requirements and individuals, and declared the applications inadmissible.Footnote 62 Member States, however, as privileged applicants, may pursue annulment actions without having to meet further standing requirements.Footnote 63
3. Indirect Challenges
Because of the difficulties of satisfying the standing requirements for direct actions, more cases are filed via indirect routes.Footnote 64 The Aarhus Convention is the foundational international agreement establishing information, participation, and access to justice rights in the context of environmental law. The EU implemented most of the Convention’s obligations that apply to EU institutions via the 2006 Aarhus Regulation, as amended in 2021.Footnote 65 The 2021 Aarhus Regulation gives environmental associations and other members of the public, subject to certain eligibility criteria, the right to initiate an internal administrative review of EU acts based on an alleged violation of EU environmental law.Footnote 66 Criteria include demonstrating independence, non-profit status, a primary objective of promoting environmental protection, at least two years of active pursuit of this objective, and alignment of the subject matter with the association’s activities.
Importantly, parties to the internal review can take a second step by filing legal action before the ECJ when not satisfied with the review’s outcome, or when the EU does not rectify the non-compliance. Environmental associations have taken this route several times. After the Commission rejected their internal review request concerning the Taxonomy Regulation,Footnote 67 the associations went to the General Court, which affirmed their direct interest in the decision regarding the internal review request but not in the Taxonomy Regulation 2020/852.Footnote 68 This indirect route hence determines the framing of the legal action, directing it away from a substantive challenge of the EU legal instrument.
In addition, if national courts have doubts about the interpretation or validity of EU law, they may ask preliminary questions to the ECJ. Highest-instance courts must do so.Footnote 69 The ECJ takes the position that legal protection before national courts in combination with the preliminary reference procedure complements direct actions and that these two avenues together form a complete system of remedies.Footnote 70 However, many challenge the effectiveness of the “complete system of remedies.”Footnote 71 First, while taking an important role in interpreting and applying EU law, national courts do not have jurisdiction to declare EU law invalid. Second, preliminary references are not a right exercised by the parties and the questions are framed by national judges. Third, a preliminary reference adds a time delay and costs to the proceedings. Fourth, the ECJ cannot establish the facts, for example, on the basis of climate science, but limits its review to matters of law. Thus, preliminary review is subject to significant limitations.
However, in line with its general conception that judicial review by national courts complements direct judicial review by the EU Courts, the ECJ imposed a duty on national courts to offer wider access to justice to associations to be able to challenge administrative decisions implementing EU environmental law.Footnote 72 It pointed out that national law could not make it “effectively impossible” for associations to bring a challenge in line with Article 9(3) Aarhus Convention.Footnote 73 Thus, EU law has here given greater effect to the Aarhus Convention and widened access to justice before national courts.
By way of conclusion, the EU adopts, within its competence, climate targets and policies that raise serious concerns as to their sufficiency and fairness. Yet, they are very difficult to challenge judicially because of the strict standing requirements for actions for annulment brought by individuals and associations. Preliminary references and challenges via the Aarhus Convention Regulation are only insufficient complementary channels for judicial challenges to reach the ECJ. Questionable EU climate targets and policies that cannot be judicially challenged are already problematic in and of themselves, as they affect human rights but deny the opportunity to demand additional justification to those whose rights they affected. However, the situation becomes even more problematic when national courts decline or seriously limit their jurisdiction because of their existence.
If EU law should be the legal layer where climate policy is democratically made, with an authoritative force, binding the Member States, it should allow also for judicial challenges to its own policy. Shutting the doors of the ECJ may be expected to shift the discussion to national courts and the ECtHR. However, the ECJ and the Commission may not reasonably expect that national courts, let alone the ECtHR, then look to the ECJ for guidance. However, if national courts and the ECtHR do not look to the ECJ for guidance, this may then necessarily lead to political and legal tensions. Moreover, being a “climate leader,”Footnote 74 as the EU projects itself, also entails allowing dissenting voices to enter the institutional discourse regarding what constitutes adequate climate policy. The adoption of adequate climate policies is a continuous process of exchange between many voices from different layers, in other words national, infra-state, EU, ECHR, and international. To better understand why the “EU-law-as-a-shield” argument is problematic in the multilayered legal context and what the legal consequences could be for the EU and the Member States if this argument is followed, we examine in the next section what international legal obligations rest on the EU and the Member States and how they relate to EU law.
C. Beyond EU Law: Obligations Under the ECHR and International Law
EU Member States are bound by their national constitutions, EU law, and international law. Legal obligations may be interpreted in light of and, at times, even displaced by EU law. However, displacement is not necessarily the result of the prevailing understanding that EU law enjoys primacy over national law and that international agreements rank between EU primary and secondary law. This section sets out the international legal obligations of the EU and the Member States as a background consideration on the potential legal consequences—responsibility under the ECHR—if national courts mistakenly interpret EU law as a shield.
I. International Obligations of the EU
The EU is not itself a member of the ECHR. Thus, it is not bound by the ECHR under international law. Yet, the ECHR has exceptional authority and status under EU law, confirmed by the Treaties and the ECJ, and is via EU law applicable both to EU and national actors.Footnote 75 Human rights obligations under national constitutional law, the EU Charter of Fundamental Rights (CFR), and the ECHR largely converge but also, at times, differ.Footnote 76
By contrast to the ECHR, the UNFCCC and the 2015 Paris Agreement are a mixed agreement, binding under international law both on the EU and the Member States. Thus, if a national court declares that a Member State’s mitigation efforts that comply with EU targets breach the state’s obligations under the ECHR read in light of the state’s commitments under the Paris Agreement—and decisions of the Conference of the Parties (COPs) under the UNFCCC—one could prima facie assume that this also entails that the EU is not complying with its obligations under the CFR and acts contrary to the ECHR, interpreted in light of the same means.
II. International Obligations of EU Member States Under the Paris Agreement
Member States are bound by the UNFCCC and the Paris Agreement, directly and under EU law, via Article 216 TFEU. Even if these international treaties cannot directly be relied on by individuals against the state and do not formulate binding emission reduction targets, they qualify as norms in the light of which courts must evaluate other legal obligations resting on the state.
The UNFCCC and the Paris Agreement, with its bottom-up approach of nationally determined contributions (NDCs) and the 1.5°C temperature limit, are unlikely to meet the requirements of direct effect under EU law.Footnote 77 Even the softer route of allowing review of EU law in light of international agreements where secondary legislative acts make explicit reference to provisions of an agreement—for example, in Fediol and Nakajima case lawFootnote 78—was shut down by the ECJ in the context of the Aarhus Convention.Footnote 79 Nonetheless, national courts remain required to interpret national law and other EU law consistently with EU international agreements.Footnote 80
In other words, while EU law does not establish that the UNFCCC and the Paris Agreement are independent yardsticks of review of the legality of national or EU law, it vests principles and obligations under the UNFCCC and the Paris Agreement with additional authority and requires consistent interpretation when identifying the content of other legal obligations, including human rights.
III. ECHR Obligations of the EU Member States
On April 9, 2024, the ECtHR—the first international court to do so—decided with KlimaSeniorinnen its first climate case. The case was brought by four elderly women and the association “KlimaSeniorinnen,” whose members are all older women. Driven by their concerns about the consequences of the climate emergency on their living conditions and health, they argued that Switzerland breached its Convention obligations by failing to take sufficient climate action. The ECtHR found Switzerland in violation of Articles 8—right to private and family life—and Article 6(1)—access to justice in civil matters—ECHR.Footnote 81 KlimaSeniorinnen establishes above all the obligations to quantify a fair share national carbon budget in line with the global 1.5°C limit—Section C.I.1.—and to ensure access to justice for associations—Section C.I.2. Both obligations are binding on the EU Member States and, by extension, relevant to the EU.
1. Procedural and Substantive Obligation
In KlimaSeniorinnen, the ECtHR confirmed “positive obligations of States relating to the setting up of a regulatory framework … geared to the specific features of [climate change],” emphasizing that “each State is called upon [under the Paris Agreement] to define its own pathway.”Footnote 82 It distinguished between a reduced margin of appreciation applying to setting of appropriate climate aims and objectives and the ordinary margin of appreciation applying to the choice of means.Footnote 83
The Court further emphasized that each state had an obligation “to do its part”—its fair share—to ensure effective protection from serious adverse effects of climate change and that its “primary duty is to adopt, and to effectively apply in practice, regulations and measures capable of mitigating the existing and potentially irreversible, future effects of climate change.”Footnote 84 Agreeing with the German Federal Constitutional Court (GFCC), the ECtHR rejected the argument of the Swiss government that there is “no established methodology to determine a country’s carbon budget,” including by reference to the CBDR-RC principle.Footnote 85 It confirmed, by contrast, that the CBDR-RC “principle requires the State to act on the basis of equity and in accordance with their own respective capabilities.”Footnote 86
More specifically, the Court established a duty to quantify a fair share national carbon budget in relation to the global 1.5°C target. It explained that when assessing whether a State stays within its reduced margin of appreciation in relation to the setting of its targets, it will examine whether the State has had:
[D]ue regard to the need to … adopt general measures specifying a target timeline for achieving carbon neutrality and the overall remaining carbon budget for the same time frame, or another equivalent method of quantification of future GHG emissions in line with the overarching goal for national and/or global climate-change mitigation commitments.Footnote 87
The court determined that no such fair share carbon budget had been set by Switzerland. To the contrary, the court concluded on the basis of Switzerland’s current climate targets it would emit significantly more that “even an ‘equal per capita emissions’ quantification approach would entitle it to use.”Footnote 88 In fact, Switzerland does not do enough because it claims a two-times larger share of the remaining carbon budget for itself than its share of the world population.Footnote 89 Importantly, the duty to quantify is not a purely procedural duty but has a significant substantive dimension.
In this context, the ECtHR also made clear that an implied budget “provided by an estimate of the remaining Swiss carbon budget under the current situation, taking into account the targets and pathways introduced by the Climate Act” is not enough, concluding that it “is not convinced that an effective regulatory framework concerning climate change could be put in place without quantifying, through a carbon budget or otherwise, national GHG emissions limitations.”Footnote 90 In other words, the Court rejected that the necessary quantification of the remaining carbon budget could be drawn implicitly from an established emission reduction percentage—that is, percentage reductions by 2030 and 2040—but demanded that the national carbon budget is determined on the basis of a “fair share” of the remaining global carbon budget for staying below the global 1.5°C target.
In more general terms, two types of obligations flowing from strategic climate litigation should be distinguished: Substantive obligations to reduce emissions by a minimum and procedural and substantive obligations to quantify a national budget. As to the first, the DutchFootnote 91 and BelgianFootnote 92 courts established a substantive minimum that the respective state had to reach in terms of emission reductions—25% in 2020 and 55% in 2030, respectively. This substantive minimum falls short of equity because judges—based on separation of powers considerationsFootnote 93—do not enter into the difficult task of determining what is fair but only establish what the absolute substantive minimum reduction percentage, which when adopted by all states does not add up to staying below the 1.5°C temperature limit.Footnote 94 As to the second, KlimaSeniorinnen established the duty to quantify a fair share carbon budget. Here, the ECtHR emphasized that any such quantification must be based on substantive considerations, including not only a “domestic pathway” setting out what is needed in light of climate science to stay below the 1.5°C temperature limit but also applying legal principles giving expression to ethical norms ensuring that national efforts are fair in relations to what is needed globally.Footnote 95
2. Access to Justice for Associations
In addition, KlimaSeniorinnen established a procedural obligation to ensure adequate access to justice by environmental associations. To establish standing before the ECtHR, the Court extensively referred to the Aarhus Convention, which gives great importance to associations as vehicles of public participation and speaks of “an evolution in contemporary society as regards recognition of the importance of associations to litigate issues of climate change on behalf of affected persons.”Footnote 96 At the same time, the Court mentioned in a sidenote that standing of associations in the context of climate-change litigation was not covered by the Aarhus Convention and emphasized that preventing actio popularis under the ECHR requires a more restrictive approach to the standing of associations, informed by “the specific features of climate-change litigation,” than provided by the Aarhus Convention, which deal with “more linear and localized (traditional) environmental issues.”Footnote 97 Whether the Aarhus Convention applies to strategic climate litigation is at best controversial and may depend on the circumstances.Footnote 98 It is in any event not for the ECtHR to determine the scope of the Aarhus Convention.
In any event, the ECtHR confirmed the exceptional relevance of associations to defend common interests in the context of climate litigation, which “involves complex issues of law and fact, requiring significant financial and logistical resources and coordination” and the outcome of which “will inevitably affect the position of many individuals.”Footnote 99 It widened the standing requirements under the Convention in the climate context to allow associations standing “as representatives of the individuals whose rights are or will allegedly be affected” and “despite the fact that it cannot itself claim to be the victim of a violation”Footnote 100 Importantly, associations do not have to establish the victim status of their members.Footnote 101 This is a pragmatic way of bundling floods of cases brought by individuals before they reach the court and improving the evidentiary and legal foundations of these actions by being able to rely on the significant knowledge, expertise, and resources of associations, while protecting the democratic contribution that associations can make to decision-making, including through judicial recourse.Footnote 102
Finding a violation of Article 6 ECHR for the part of the applicant association’s action before national courts that concerned an alleged failure to enforce existing laws,Footnote 103 the ECtHR re-emphasized “the key role which domestic courts have played and will play in climate-change litigation” and found that the fact that the substance of the complaint had not been dealt with at any level led to an impairment of the “very essence of the right.”Footnote 104 The Swiss courts did not deal with the standing of KlimaSeniorinnen at all; yet, the ECtHR’s reasoning and its approach to standing in Strasbourg indicates that simply denying access to justice to environmental associations by introducing disproportionately high standing requirements is a breach of the Convention, particularly in climate litigation.
The two legal layers of EU law and the ECHR, under which the EU Member States operate, interpret the role of associations differently. The ECJ could so far be accused of failing to acknowledge the particular relevance of access to justice of associations for collective interests before the EU courts. Direct and individual concern remains an excessively high hurdle. However, in line with the ECJ’s position that direct actions are complemented by preliminary references, the ECJ has pushed Member States to offer greater access to justice to associations before national courts.Footnote 105 Arguably, this could meet the ECHR’s standard. However, if Member States were able to use EU climate targets and policies as a shield in national proceedings, broader standing of associations under national law would not actually result in judicial review of climate targets and policies. In other words, Member States may still breach the ECHR standard of access to justice by avoiding substantive assessment of their climate policies.
3. Bosphorus: Equivalent Protection Under EU Law?
The ECtHR has shown great deference to the EU and the ECJ. In Bosphorus, it recognized that Convention Parties remain “responsible … for all acts and omissions of … [their] organs regardless of whether the act or omission in question was a consequence of domestic law or of the necessity to comply with international legal obligations.”Footnote 106 They cannot be absolved “completely from their Convention responsibility.”Footnote 107 However, states may use compliance with obligations resulting from the membership of an international organization—in other words, the EU—as a valid justification that there is no breach of the Convention, “as long as the relevant organisation is considered to protect fundamental rights, as regards both the substantive guarantees offered and the mechanisms controlling their observance, in a manner which can be considered at least equivalent to that for which the Convention provides.”Footnote 108 The protection does not have to be identical; this “could run counter to the interest of international cooperation.”Footnote 109 It merely has to be “comparable.” In other words, the “systemic equivalence of systems” leads to a “concrete presumption of compliance.”Footnote 110
The ECtHR did not engage in a more detailed review of the ECJ’s interpretation of the standing rules under Article 263(4) TFEU in Bosphorus, but concluded more globally that the rights protection offered by the EU was systemically equivalent to the protection under the ECHR. In line with this, the European Commission argued in its third-party intervention in the case of Duarte Agostinho before the ECtHR that:
[W]hen applying the Bosphorus criteria, EU law can be considered to provide for an equivalent level of protection of human rights to that of the Convention in the field of environmental protection. Therefore, Member States of the EU can be presumed not to have departed from the requirements of the Convention when they implement the legal obligations flowing from their membership to the EU.Footnote 111
However, the ECtHR conceded in Bosphorus that “any such finding of equivalence could not be final and would be susceptible to review in the light of any relevant change in fundamental rights’ protection.”Footnote 112 And that “any such presumption can be rebutted if, in the circumstances of a particular case, it is considered that the protection of Convention rights was manifestly deficient.”Footnote 113 The extensive engagement of the ECtHR with the exceptionality of climate change and its willingness to adapt its settled case law on environmental issues in order to “tailor” it to these exceptional circumstances indicates that the Court grasps the omnipresent and unprecedented manner in which the climate crisis does and will affect Convention rights of nearly everyone within the territory of the Contracting Parties.Footnote 114 One could imagine that, with increasingly grave climate impacts in Europe, the ECtHR could find a “manifest inadequacy” that justifies a rebuttal of the Bosphorus presumption if the EU does not take adequate measures. This includes failing to ensure the right to access to justice of associations representing human rights claims in the climate context.
What is more, in its later case law, the ECtHR specified that “a State will be fully responsible under the Convention for all acts falling outside its strict international legal obligations, notably where it has exercised State discretion.”Footnote 115 In other words, because EU law permits Member States to adopt more stringent national climate targets and policies—see Section B.I.—they do not benefit from the Bosphorus presumption.
By way of conclusion, KlimaSeniorinnen established climate obligations under the ECHR that are higher than the Member States’ climate obligations under EU law. While the Paris Agreement is unlikely to enjoy direct effect under EU law, it forms as an EU agreement part of EU law and must therefore serve a means of interpretation for other legal obligations resting on the Member States. In addition, the EU itself does not meet the climate obligations under the ECHR, as established by KlimaSeniorinnen. The restrictive access to justice requirements for associations before the EU courts are not in line with Article 6 ECHR as interpreted by the ECtHR in the context of climate change. Moreover, the EU has not only thus far failed to quantify its fair share carbon budget for 1.5°C, but existing scientific analysis also leaves little doubt that the EU’s climate targets and policies substantively do not comply with what is needed in terms of global emission reductions, see Section B.III.1.
These tensions between obligations under the ECHR and EU law expose Member States to potential responsibilities under the ECHR if national courts accept the “EU-law-as-a-shield” argument. The Bosphorus presumption is not applicable. This is a consequentialist argument against hiding behind EU law that should be taken seriously by the defendant states and the deciding national judges. Nonetheless, the next section shows that several national judges have—before KlimaSeniorinnen was decided—used EU law to either deny jurisdiction or limit their judicial review of national climate policies. In addition, it explains why, from the perspective of EU doctrine, this is indefensible.
D. EU Law as an Obstacle to More Stringent National Climate Action?
This section first sketches four cases of strategic climate litigation, in which national judges have in 2023 and 2024 accepted different versions of the “EU-as-a-shield” argument—Section D.I. It then argues that judges were mistaken from the doctrinal perspective of EU law to do so—Section D.II.
I. EU Law Acting as a Shield in Strategic Climate Litigation
In strategic climate litigation, states regularly put forward their compliance with EU climate law and policy as an argument in favor of the position that national courts could not review national climate law and policy. EU law was used in different stages of the procedure to argue for lack of jurisdiction or limited powers of national courts. In A Sud (Italy), EU law was considered already in the context of admissibility, while in Klimatická žaloba (Czech Republic) and Greenpeace v Spain I and II, EU law was raised as imposing boundaries to the court’s review.
A striking example is Greenpeace v Spain I before the Spanish Supreme Court. While the Court acknowledged that EU laws establish “minimum limits”Footnote 116 and hence do not prohibit the Member States from going further, it expressed concerns about the implications of declaring unlawful Spanish policy that complies with the “ambitious” EU targets. It pointed out that “the appellants themselves admit that Spain ha[d] complied with the commitments on effort sharing for the reduction of GHG emissions imposed internally by the EU” and held that any finding that the Paris Agreement requires a greater emission reduction than what EU law requires of Spain would affect “the Spanish State’s relations with the Union” by “implicitly … questioning whether the policy of the Union, also a signatory to the [Paris Agreement], would [equally] be contrary to those commitments, because … both Spain, individually, and the Union, as a regional organisation, ha[d] assumed the same commitments by signing, separately, the [Agreement].”Footnote 117 Moreover, the court wrongly considered the Paris Agreement “nothing more” than a COP decisionFootnote 118 and emphasized throughout the judgment that EU climate policies are “ambitious,” and even an example of “the most ambitious policies in the international sphere.” It did so, however, without explicating its yardstick of what is ambitious. By way of summary, the Spanish court concluded that it could not find in favor of the plaintiffs because the standards on which they relied were not legally binding (1.5°C temperature limit and science) and that it could not “implicitly” declare that EU law did not comply with international law. Greenpeace v Spain I is an illustrative example of how EU law can stand in the way of judicial review of national climate actions—yet it does not stand alone.
The Czech Supreme Administrative Court held in Klimatická žaloba earlier in 2023 that it could not conclude that the EU’s collective NDC reduction target under the Paris Agreement entailed any individual obligation of the Czech Republic.Footnote 119 National obligations under this collective target should be determined in the EU’s political and legislative process. Furthermore, the primacy of EU law prevented the court from reviewing the Czech climate target in light of other norms. It did not see it as its task “to undertake a comprehensive analysis of the sectoral provisions of EU law here, especially in a situation where the applicants ha[d] not based their climate action primarily on a breach of those provisions. Moreover, that legislation [was] gradually changing as the EU’s climate goals as a whole increase.”Footnote 120 In other words, the Supreme Administrative Court deferred to the political process in the EU specifying Czech climate obligations and did not carry out an autonomous assessment.
The Court of Appeal in Klimaatzaak (2023) concluded that the fact that the EU has adopted a binding legal framework for emission reduction cannot allow the Belgian state to hide behind these provisions.Footnote 121 The court also concluded that it could not go further than holding the state to an absolute minimum.Footnote 122 Besides pointing repeatedly at the principle of separation of powers, emphasizing that effort-sharing is based on political values, and arguing that if scientific studies “retained” scenarios based on a 50% likelihood—rather than only a 67% likelihood—it could also only hold the state to a 50% likelihood,Footnote 123 the court came to this conclusion by relying heavily on EU law.Footnote 124 The Court then explicitly assessed whether the EU target of 55% reduction was compatible with the threshold of 1.5°C in a scenario of a 50% chance of success.Footnote 125 Ultimately, it came down on precisely the EU target of 55% as the minimum threshold for Belgium.Footnote 126 Thus, in Klimaatzaak, while not standing in the way of judicial review, the EU target greatly influenced what the court was substantively willing to hold the Belgian state and its regions to do as a minimum, in light of separation of powers.
In A Sud in Italy, the CFI (Rome) concluded in 2024 that the plaintiffs, in this civil law case, had essentially requested the Court to annul national climate measures, which reflected political choices of the legislature and the executive and aimed to implement obligations under international and EU law.Footnote 127 The court found that if it acted upon this request, it would violate the principle of separation of powers. After reconstructing the EU law framework, the Court pointed out that the plaintiffs had not used their remedies provided by European law to challenge the lawfulness of the EU acts under Article 263 TFEU.Footnote 128 It further explained that what the plaintiffs asked was “liability of the so-called State-legislator, which cannot be predicated except in cases of violation of European Union law.”Footnote 129 EU law played a considerable role in justifying the inadmissibility of the plaintiff’s complaint, ultimately because any review would encroach upon “the sphere reserved by the Constitution to the legislator State.”Footnote 130 Thus, while the Italian court was not as outspoken as the Spanish Constitutional Court about the way EU law constituted an obstacle to judicial review by the national court, it becomes clear from the Italian court’s reasoning that the existence of an EU legal framework for emission reduction that was not challenged by the plaintiffs and the fact that the plaintiffs did not argue that national climate action failed to comply with EU law were central to its declaration of inadmissibility.
To complete the picture, however, in two earlier landmark cases by the Dutch Supreme Court and the GFCC, respectively, EU law was not considered an obstacle to judicial review. In Urgenda, the Dutch Supreme Court concluded unambiguously that the Netherlands is bound to its human rights obligations under the ECHR and that this means that the State may need to adopt stronger mitigation measures than what is required under EU law to meet its own Convention obligations.Footnote 131 The Court of Appeal in the Urgenda case (2018) confirmed that “Article 193 TFEU states that protective measures adopted under Article 192 TFEU do not prevent a Member State from maintaining and adopting more ambitious protection measures, provided that such measures are in line with the Treaties.”Footnote 132 The Dutch State argued, similarly to the reasoning of the Spanish Supreme Court, that the decision of a national court that the EU-compliant Dutch climate policy was unlawful would entail an implicit decision that the EU policies—ETS and ESR—are also unlawful.Footnote 133 By contrast, the procureur general argued that because Member States may, from the perspective of EU law, adopt more stringent reduction targets, any judgment that the Dutch State is obliged by norms other than EU law—for example, the duty of care under the ECHR—to go further than what EU law requires, does not entail even an implicit position about the lawfulness of EU targets and policies.Footnote 134 The national judge assesses the Dutch States’ obligations in light of the specific circumstances of the case—GHG emission per capita, reduction so far, et cetera.Footnote 135 This does not allow a generalization to other states or the EU. In Neubauer, from 2021, the GFCC explained even more to the point that the EU-derived mitigation targets are irrelevant for the assessment of the lawfulness of a state’s conduct.Footnote 136 This is due to the framing of the constitutional complaint procedure and the standpoint of the GFCC on the relation between EU law and rights protected under the German Constitution.
In other words, the relevance of an EU legal framework in the context of strategic climate litigation is interpreted very differently by national courts. If anything, however, in more recent cases, judges have given greater weight to the “EU-law-as-a-shield” argument. It should be added though that all examples predate the ECtHR’s judgment in KlimaSeniorinnen, which may remind national judges of the Convention obligations resting on the defendant states.
II. Assessing the “EU Law as a Shield” Argument
In none of the climate cases discussed in the previous section, EU law was challenged. Yet, when national courts determine that a Member State’s EU-compliant climate policy is unlawful in light of national and/or international human rights law, this could be seen as entailing an implicit “view” about the insufficiency and/or unlawfulness of the EU’s targets and policies. However, an implicit view that EU efforts are insufficient is legally possible and arguably even legally mandated. This does not change that national judges cannot formally declare EU law unlawful.
Critics argued that declaring national emission reduction targets incompatible with the ECHR “implies that those EU targets, on which the national ones were explicitly based, are in the view of the [national court] equally in conflict with the relevant provisions of the ECHR.”Footnote 137 When we consider this argument, we need to distinguish between substance and form. We must distinguish between the substantive sufficiency, in other words scientific soundness in light of legal and political commitments, such as the 1.5°C temperature limit,Footnote 138 on the one hand, and the lawfulness as determined by the national judge in light of the applicable legal norms, on the other. Substantively, the conclusion of an assessment of the facts—scientific and political commitments—that national climate action is insufficient could be transferrable to the extent that the facts are the same—for example, scientific evidence, COP commitments under the UNFCCC, but also considerations of cost efficiency. Formally, however, the legal grounds that the national judge puts forward in her reasoning are not applicable to the EU. A national court’s reasoning and decision that national climate targets and/or policies infringe human rights norms as they are binding on the state under the national constitution, as in Neubauer, or the ECHR, as in Urgenda, or even ordinary tort law,Footnote 139 cannot and do not challenge EU law. First, national courts do not have jurisdiction, nor did they pretend in any of the examined cases to have jurisdiction, to review the validity of EU law. Second, a national judge’s decision that national climate action is unlawful results from an autonomous application and interpretation of the legal grounds on which the national judge bases her decision. These legal grounds would also have to be applicable to the EU, which is not the case for national law—be it the national constitution or tort law—and is also not directly the case for the ECHR. Admittedly, the ECHR applies to the EU via the EU Treaties, including the CFR. However, it does so only via the ECJ’s autonomous interpretation of the ECHR.Footnote 140 In other words, legal norms apply formally differently to the EU and the Member States. Legal grounds of a judgement are the autonomous interpretation of these norms by a judge within her jurisdiction to the case at hand.
As long as EU law allows for more stringent measures, the primacy of EU law cannot be seen to stand in the way of other national obligations requiring more stringent action. EU law explicitly permits more stringent national measures in the context of climate governance, whether they result from legislative acts or from decisions of the judiciary. The European Commission accepted in Duarte that minimum harmonization does not create a legal obstacle to Member States setting themselves more ambitious targets.Footnote 141 Under these circumstances, the judgment of a national court that a state must do more in terms of climate mitigation is not contrary to EU law. It should also be added that several Member States have adopted national climate targets and policies that go well beyond their EU law obligations.Footnote 142
Furthermore, national judges must remain in the position to review national climate action in order to avoid an unacceptable lacuna in judicial protection. National judges are mandated and legally required to rule on disputes brought before them in light of the applicable, valid, and binding law within the legal order of their state. As a result, they must interpret and concretize what the legal obligations resting on the state mean, potentially in light of other international, European, and national norms, facts and other means of interpretation. In light of the above conclusion that EU climate targets and policies cannot be adequately subjected to judicial review brought by natural and legal persons, including associations, national judges’ blind deference to EU law would create a judicial vacuum, which—as explained above—cannot be filled by referring a preliminary question to the ECJ. Additionally, if national judges do not assess the legal obligations and responsibilities of their state in light of all binding, valid and applicable legal norms, but stop at stating that their state’s climate policy is in line with EU law, they deprive all other—non-EU—international and national legal obligations and principles, including human rights, of value within their legal order. This would result in an all-prevailing force of EU law that goes further than the interpretation of primacy by the ECJ.
Finally, in light of the formal limitations of the effects of rulings of national courts and the fact that EU law permits the adoption of more stringent national law, be it a legislative act or a judicial decision, any obligation of the national judge to ask a preliminary question, when she declares unlawful national climate policies that implement EU law, is also questionable.
E. Conclusions
The EU takes a central role in the adoption of climate targets and policies in Europe. It is competent to adopt climate targets and policies and does so. Yet, the EU’s targets and policies remain insufficient in that they fall far short of a fair share contribution to global emission reductions interpreted in light of equity principles of international law. They are even insufficient when compared to global pathways that are based on cost efficiency rather than equity considerations.
At the same time, natural and legal persons, including associations, find it notoriously difficult to challenge EU climate targets and policies. Direct actions against EU laws are subject to strict standing requirements. Indirect actions via the preliminary ruling procedure and the Aarhus Convention Regulation do not put parties in the position to challenge EU climate acts on their merits. Because of these procedural hurdles, strategic climate litigation is largely brought before national courts.
In 2023 and 2024, the Czech Supreme Administrative Court, the Spanish Supreme Court, and the Court of First Instance in Rome accepted EU law at different stages of the procedure to be an obstacle to judicial review. In the Czech and Spanish cases, EU law led to a restrictive interpretation of judicial powers in light of separation of powers. In the Italian case, it led to a declaration of inadmissibility. In addition, the Belgian Court of Appeal in 2023 heavily relied on EU law to construe a yardstick of what is the absolute substantive minimum of emission reduction. Thus, even where EU law does not exclude judicial review, it may affect the way national judges review national climate policy on the merits.
The combination of the EU not doing enough and setting up high procedural hurdles for civil society actors to challenge its policies is as such highly problematic. It hinders civil society and individuals to demand additional justification for alleged failure to protect them from the climate crisis. It closes down an avenue for democratic exchanges about EU climate policies. When national judges then allow states to hide behind the EU’s multilayered legal order and justify that they do not review national climate policy because it complies with EU law the situation becomes even more problematic.
When national courts accept the “EU-law-as-a-shield” argument, EU Member States are exposed to the possibility of being held responsible for violating the ECHR. EU Member States have their own legal obligations under their national constitutions and international law, such as the ECHR, the UNFCCC, and the Paris Agreement. The ECtHR confirmed in KlimaSeniorinnen the justiciability of human rights infringements through inadequate climate policy. Some international obligations of the EU Member States may be shaped or even strengthened by EU law; yet Member States cannot—as the ECtHR already held in its Bosphorus decision of 2006—use EU law as a shield when Member States exercise discretion, as they do in the climate context, when not adopting possible more stringent measures, or when the EU structurally and manifestly fails to uphold human rights. The ECtHR has demonstrated in KlimaSeniorinnen how seriously it takes the all-encompassing problem of the climate emergency. Arguably, the EU fails on both obligations explicated in KlimaSeniorinnen: It does not offer Convention-compliant access to justice to associations, and it does not give sufficient consideration to equity principles of international law when quantifying its fair share domestic carbon budget in relation to the global 1.5°C temperature target.
This Article demonstrated how the structural features of the EU legal order may become problematic in interplay with national and international law in the context of strategic climate litigation. However, as the Article also showed EU law does not require national courts to decline or limit review of national climate policies. From the standpoint of EU law, EU law is not an obstacle to judicial review of national climate action by national judges. National judges cannot only review but also declare the national emission reduction targets insufficient and unlawful without infringing EU law. From the perspective of EU law, it is possible for national courts to impose a positive duty to adopt more ambitious climate mitigation targets than those enshrined in EU legislation. Finding that national climate targets fall below what the state is obliged to do by higher ranking norms in light of international political commitments, science, and principles of international law cannot and is not a judgement about the lawfulness of EU climate laws.
Finally, the combination of the EU not offering ECHR-compliant access to justice for associations in strategic climate litigation and national courts accepting the EU-law-as-a-shield argument results in a situation that human rights and democracy are lost in between the different legal layers in Europe. If EU climate law, which itself is more weakly democratically legitimized than national law and particularly immune to judicial challenges, particularly in the climate emergency,Footnote 143 is interpreted as an obstacle in strategic climate litigation before national courts, EU law becomes a negative limitation on institutional decision-making processes. This includes the legislature, the executive and the judiciary, which all three form part of the trias politicas that underpins the democratic process.Footnote 144 Again, in the particular context of the climate emergency, which is complex, multi-layered, concerns every aspect of living, and has exceptional re-distributive consequences, both in terms of impact and mitigation measures, robust democratic exchanges constitute an important pre-requisite for adequate problem-solving.
Acknowledgements
I would like to thank the editors of this special issue for their helpful comments.
Competing Interests
The author declares none.
Funding Statement
Co-funded by the European Union (ERC, LitDem, 101125511).
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