Reparation for Climate Change: The Successes and Limits of Litigation

April Williamson, Joe Udell and Filippo

P.Fantozzi*

Chapter 7: Success in Climate Litigation — the Impacts and Influence of Systemic Litigation against Governments

1.Introduction

The field of climate litigation has grown immensely over the last decade, with numerous cases progressing to judgment in first instance, appeals and apex domestic courts, as well as regional courts. To that end, enough time has elapsed to properly evaluate the impacts of these cases beyond the rulings themselves, and to explore what constitutes “success” in climate litigation. Through a case-study analysis of “framework” or “systemic” mitigation cases, this chapter considers the types of positive, real-world impacts that climate litigation can have to illustrate how success can take many different forms.

Framework climate litigation challenges a government’s overall efforts to mitigate climate change.¹ Researchers have found that these types of cases have had “a significant impact on government decision-making, requiring governments to develop and implement more ambitious policy responses to climate change.”² To date, framework cases have targeted both the ambition of governments’ emissions reduction targets and/or the implementation of the policies and measures that governments have adopted to achieve these targets. As of June 2024, claimants around the world have filed over 100 such cases, invoking a wide variety of legal and factual arguments.³ A range of

landmark victories have followed, with courts ordering governments to increase their emissions reduction efforts (eg Switzerland,⁴ the Netherlands,⁵ Germany,⁶ South Korea⁷ and Belgium⁸), clarify their climate plans (eg Ireland⁹ and the United Kingdom¹⁰) and implement their existing mitigation targets (eg France¹¹ and Germany¹²). The legal basis and background of the plaintiffs in framework cases have taken various forms. This chapter will focus on framework cases that concern human rights and constitutional rights and tort law. Concerning human rights and constitutional rights, many framework cases have sought to rely on human rights or constitutional rights as the basis for claiming that governments have not taken sufficient mitigation action.¹³ This aligns with scenario 1, which seeks to compel the national government to achieve higher mitigation ambition on the basis of the right to life (Article 2 of the European Convention of Human Rights (ECHR)) and the right to private and family life (Article 8 ECHR). Scenario 5 also relies on fundamental rights, with an emphasis on the right to a healthy environment, the rights to access to basic needs, property and culture, all of which may also be engaged in this type of framework case. Some cases have taken the approach of using tort law to argue that governments have a duty of care to mitigate the adverse effects of climate — S. 137 —change.¹⁴ Situations similar to those in scenario 3, where particularly effected individuals may have already suffered damage or are facing impending threats to their property or business, could rely on tort law to initiate a claim. Although scenario 3 does not include a tortious claim, it is notable that a real claim in Italy has been initiated by individuals and non-governmental organizations on the basis of tort law in respect of the government’s mitigation action.¹⁵ In some jurisdictions, human rights violations can also serve as a basis for illustrating a breach of tort law,¹⁶ while others may have specific tortious liability provisions relating to environmental damage.¹⁷

But what does “impact” and “success” look like in practice? One can best envision the different elements of success in climate litigation as a pyramid (see Figure 1, below). There are both direct and indirect impacts that can be linked back to success in framework cases.

Legislative

reform

Policy

engage-

ment

Public

Campaigns awareness — S. 138 —The bottom three triangles of the pyramid concern direct impacts, while the top four triangles concern indirect impacts.

In terms of direct impacts:

—Legally binding judgments: Centered at the base of this figure sits the

main objective of any climate litigation case: a legally binding judgment. This outcome can take the form of an order or injunction (to compel a government to do something, or to stop it from doing something) or a declaration (which could concern whether a government has properly complied with its legal obligations). Legally binding judgments play an important role in furthering other impacts at the base of the impact pyramid.

—Normative development: Court judgments have the potential to advance

the authority of international environmental principles, such as common but differentiated responsibilities and respective capabilities (CBDR-RC), intergenerational equity and the precautionary principle, as well as the prevailing scientific consensus around climate science. Once one or more courts have accepted principles or scientific standards, others may be more likely to follow suit in cases covering similar issues.

—International precedents: International precedents can be highly per-

suasive. For example, courts may look to decisions in jurisdictions with a similar legal framework, especially if that court is adjudicating an issue for the first time. This can create a positive feedback loop that supports future climate litigation.

The upper levels of the pyramid encompass the potential indirect impacts of a case. By considering these factors, one can assess success in climate cases more comprehensively:

—Public awareness and campaigns: Litigation cases have the potential to

shift the public debate, driving the narrative that climate action is a legal duty. Climate cases are often high-profile disputes that span a number of years, depending on the legal determinations and appeals processes. Accordingly, these cases have the potential to raise the profile of climate issues in the public consciousness and mobilize support for climate action, independent of any eventual determination by the court.¹⁸ Numerous — S. 139 —framework climate cases have led to widespread public mobilization on the urgency of climate action. For example, over two million people signed a petition to support the French climate case,¹⁹ while nearly 60,000 people joined the VZW Klimaatzaak v Kingdom of Belgium et al (Klimaatzaak) case as co-claimants.²⁰

—Policy engagement and legislative reform: Based on the level of visibility

and public support for a particular case, individuals, communities and civil society organizations may find themselves with newfound leverage to engage with the political process to advocate for the adoption of new climate legislation or reforms. If, for example, courts have issued declaratory relief, plaintiffs and wider civil society actors may have the opportunity to work collaboratively with governments to identify the means by which to change law and policy to allow the government to comply with its legal obligations. The International Panel on Climate Change (IPCC) has made clear in its latest report that “climate litigation can affect the stringency and ambitiousness of climate governance.”²¹

This chapter first explores the remedies granted, as well as the wider influence of the court decisions, in three landmark framework mitigation cases concerning government ambition — Urgenda Foundation v State of the Netherlands (Urgenda),²² Neubauer et al v Germany (Neubauer)²³ and Klimaatzaak.²⁴ Urgenda has been selected as a case study, as it was the first successful framework case in Europe and has therefore had the longest amount of time for impacts to become clear and documented. Likewise, Neubauer was decided in 2021, allowing enough time for impacts to be identified. This case also has some of the most well-documented and immediate direct impacts of any framework case. Klimaatzaak is a slightly more recent case, decided by the Belgian Court of Appeal in 2023. This has been selected to provide examples of impacts after a judgment from a non-apex court. All three case studies are in Europe, where it has been easier to monitor direct and indirect impacts more comprehensively based on desktop research. By focusing on these representative examples, this chapter seeks to illustrate how each case has achieved some or all of — S. 140 —the direct and indirect impacts described above, and thus achieved success in this complex and rapidly evolving field.

2.Urgenda Foundation v the State of the Netherlands

a.The Case

The Urgenda case was initiated in 2013 by the Urgenda Foundation and 886 Dutch citizens.²⁵ The claimants alleged that the state’s failure to take greater steps to reduce greenhouse gas (GHG) emissions by 2020 was unlawful under Article 6:162 of the Dutch Civil Code, which relates to tortious liability, and Articles 2 and 8 of the ECHR, which respectively protect the right to life and the right to private and family life.

The claimants made two key requests in the original summons:

i)A declaration that the Dutch state is acting unlawfully towards the claim-

ants in the event it does not take appropriate measures to reduce greenhouse gas emissions in the Netherlands to a level of 40%, or at least 25%, below the level of 1990 before 2020; and

ii) An injunctive order for the Dutch state to limit greenhouse gas emissions

in the Netherlands to a level of 40%, or at least 25%, below the level of 1990 before 2020.

As part of the injunctive order, the claimants also requested that, within six months of the judgment, the Dutch State present to Parliament a program of measures with corresponding budgets to achieve the prescribed emissions reductions by 2020.

In 2015, the District Court of the Hague ruled in favor of the Urgenda Foundation.²⁶ It found that the Dutch Government had a legal duty to protect its citizens from dangerous levels of climate change pursuant to its duty of care under the tort of hazardous negligence. It ordered the Government to reduce Dutch emissions by at least 25% compared to 1990 levels by 2020. Notably, the Court emphasized that it remained the prerogative of the Government to determine how it would reduce Dutch emissions.

In 2018, the Court of Appeal upheld the injunctive order of the District Court.²⁷ Importantly, the Court also accepted that the Urgenda Foundation was able to rely on the ECHR and premised the state’s obligation to reduce GHG emissions squarely on its positive obligations under Articles 2 and 8 of that instrument.

In 2019, on the basis of its findings in respect of both tort law and human rights law, the Supreme Court of the Netherlands affirmed the findings of the Court of Appeal and upheld the injunctive order for the Government to reduce its national emissions by at least 25% compared to 1990 levels by 2020.²⁸ The Supreme Court made the unequivocal finding that the state bears individual responsibility to mitigate climate change. This conclusion was derived from the state’s binding obligations and non-binding commitments under the UN Framework Convention on Climate Change (UNFCCC),²⁹ the Paris Agreement,³⁰ the “no harm” principle, principles of equity and CBDR-RC and soft law sources such as the UNFCCC Conference of the Parties decisions.

b.The Wider Impacts of the Case

Urgenda marked the first time that a national court ordered a government to increase its climate ambition. This case provided an invaluable precedent, both at the national and international levels, that governments can be held accountable in court for insufficient mitigation efforts. Additionally, Urgenda greatly influenced the trajectory of climate litigation around the world, with a wave of similar cases filed after the district court decision in 2015.³¹

Nationally, the case led to a tangible transformation in Dutch climate policy. Following the Supreme Court decision, the Government immediately closed one coal-fired power station;³² pledged to scale down the capacity of its remaining coal-fired power stations by 75%;³³ and unveiled a EUR 3 billion package of measures to reduce Dutch emissions by the end of 2020, in line — S. 142 —with the Court order.³⁴ Most of the measures that the Government adopted mirrored proposals from Urgenda’s “54 Climate Solutions Plan,” which was submitted to the Government on behalf of more than 800 Dutch organizations and businesses.³⁵

In 2020, the Government stated that it achieved a 25.5% reduction in greenhouse gas emissions compared to 1990, thus achieving the minimum emissions reductions required by the Court.³⁶ In 2022, the Government stated that it achieved a 30% reduction below 1990 levels, making strong progress towards its 2030 target (55% below 1990 levels).³⁷

The Supreme Court’s decision continues to have influence over policy setting and debate in the Netherlands. In 2021, the Dutch Government committed to spending an additional EUR 6.8 billion on climate change measures.³⁸ The following year, it pledged to make EUR 35 billion available for major climate action, including a hydrogen network and EUR 20 billion to further facilitate economy-wide decarbonization.³⁹ In 2023, Rob Jetten, the Climate and Energy Policy Minister at the time, noted the following in an interview:

[E]ver since the verdict the debate is much more about our own responsibility. Politics in the Netherlands was probably also trying to protect Dutch companies that play a huge role in the fossil fuels economy. But it’s very useful to use the verdict in my debates with other ministers and Parliament, and tell them there is no choice, we got to do this.⁴⁰

Moreover, in 2023, the Government acknowledged the findings of the Supreme Court in Urgenda in separate climate change-related proceedings at the European Court of Human Rights (ECtHR). The Government’s observations notably illustrated the role that national courts play in the enforcement of human rights: — S. 143 —In the Urgenda case the Supreme Court explicitly found that the Netherlands is obliged, under Articles 2 and 8 of the [European Convention on Human Rights] to do “its part” in order to prevent dangerous climate change, even if the problem itself is global in nature.⁴¹

3.Neubauer et al v Germany

a.The Case

In February 2020, the Neubauer case began when nine young people filed a complaint with the German Federal Constitutional Court.⁴² The claim challenged the provisions of Germany’s Climate Protection Act (KSG) that established a GHG emissions reduction target of 55% by 2030 compared to 1990 levels, on the basis that it was insufficient in light of scientific evidence and therefore violated constitutionally protected fundamental freedoms.

The claimants requested that the Constitutional Court make the following orders:

i)That the legislator ensures, within a period of time to be set by the Con-

stitutional Court, that GHG emissions in Germany are kept as low as possible, on the basis of comprehensible forecasts; and

ii) That the federal legislator creates legal provisions, within the period of

time to be set by the Constitutional Court, that prohibit Germany from permitting the transfer of emission allocations to neighboring European countries, for as long as EU climate protection law does not provide a level of protection adequate to protect basic rights.

The Constitutional Court determined that it was appropriate to assess whether the legislated GHG emissions reduction measures were “manifestly unsuitable or completely inadequate”⁴³ in light of the Government’s constitutional duty to protect the claimants’ human rights from climate-related harms.

Neubauer focused in part on the climate protection required under Article 20a of the Constitution.⁴⁴ The Court made clear that “[it] is not, in principle, — S. 144 —for the Courts to translate the open wording of Art. 20a […] into quantifiable global warming limits and corresponding emission amounts or reduction targets.”⁴⁵ However, it concluded that it had the competency to “review whether the boundaries of Art. 20a […] are respected” and that “[there] is nothing to indicate that Art. 20a […] is beyond the scope of judicial review with regard to how its regulatory content is interpreted and applied.”⁴⁶

The Court then took an approach to the interpretation of the claim that was not directly pleaded by the claimants. The Court did not uphold the claimants’ argument that the inadequacy of the 2030 target constituted a violation of the Government’s positive obligations to protect their constitutional rights from the harms posed by climate change.⁴⁷ The Court also found that the claim regarding the transfer of emissions allowances between European Union (EU) Member States was inadmissible, and that it was insufficiently substantiated.⁴⁸

Despite these findings, the Court went on to assess how the 2030 target would require the future imposition of harsh GHG reduction measures post-2030, which it found would violate the claimants’ (unspecified) constitutional “freedoms.” The Court noted that the legislative objective of the KSG is to limit global temperature rise to well below 2°C, and preferably to 1.5°C, above preindustrial levels, in accordance with obligations under the UNFCCC and the Paris Agreement. The Constitutional Court took this as the relevant standard under constitutional law and relied on information from the German Advisory Council on the Environment to infer that Germany’s remaining carbon budget to limit global average temperature to 1.75°C with a probability of 67% would be “largely used up” by 2030 if the state were to comply with its existing targets. The Government’s targets would therefore require a drastic reduction of emissions after 2030, which would then necessitate significant sacrifices and restrictions on personal freedoms in order to stay within Germany’s fair share of the carbon budget. The Court ultimately concluded the following:

[O]ne generation must not be allowed to consume large portions of the CO2 budget while bearing a relatively minor share of the reduction effort, if this would involve leaving subsequent generations with a drastic reduction burden and expose their lives to serious losses of freedom.⁴⁹

For this reason, the Court declared that the legislation was partially “unconstitutional insofar as [it] give[s] rise to risks of future impairments of fundamental rights.”⁵⁰ As such, the Government violated its duty “to ensure that the reduction of CO2 emissions to the point of climate neutrality that is constitutionally necessary under Art. 20a […] is spread out over time in a forward-looking manner that respects fundamental rights.”⁵¹ The Court accordingly ordered Germany to revise its reduction targets from 2031 by the end of 2022.

b.The Wider Impacts of the Case

The Constitutional Court’s decision had a dramatic impact on German climate policy. Within a week of the decision, the German Government announced that it would increase its GHG reduction target from 55% to 65% by 2030 (compared to 1990 levels).⁵² The more ambitious 2030 goal will require the energy industry to quickly shift towards a more sustainable model. Instead of 175 million tons CO2 equivalent under the previous target, it will only be allowed to generate 108 million tons.⁵³ In May 2021, the German Government also disclosed its decision to further accelerate the country’s decarbonization through an EUR 8 billion investment in 62 large-scale hydrogen projects.⁵⁴

The Government formally amended the KSG in June 2021. Beyond enshrining the 65% GHG reduction goal into law, it also adopted an intermediate reduction target of 88% by 2040, and brought forward its climate neutrality deadline from 2050 to 2045. The Government further noted that “[t]he Court ruling obliges the state to take action to prevent any future disproportionate restrictions in the fundamental liberties of today’s young generation.”⁵⁵

Additionally, on 23 June 2021, the Government approved an Immediate Action Program worth EUR 8 billion to help achieve its updated climate goals. The ambition of the program is to generate support for the progressive decarbonization of the industrial sector, as well as for green hydrogen, energyfocused building refurbishments, climate-friendly mobility, and sustainable forestry and agriculture. Through these initiatives, the Government has invested — S. 146 —in “measures that allow for short-term effects” that will reduce greenhouse gas emissions in a verifiable way.⁵⁶ The Government also set up a monitoring scheme under which the Council of Experts on Climate Change will present a report of the goals achieved every two years, as well as measures and recorded trends. If the relevant budgets are not met, the Government stated that it “will adjust its approach immediately.”⁵⁷

4.Klimaatzaak et al v Belgium

a.The Case

The case of VZW Klimaatzaak v Kingdom of Belgium et al was filed in 2015 by Klimaatzaak, a non-profit organization, and 58,000 Belgian citizens against the Belgian Federal Government, the Walloon Region, the Flemish Region and the Brussels-Capital Region.⁵⁸ The claimants alleged that the defendant government authorities were in breach of their obligations under Articles 2 and 8 of the ECHR and under the Belgian Civil Code (Articles 1382 and 1383, which concern tortious/extra-contractual liability) because of their failure to adopt adequate emissions reduction measures.

The claimants asked the Court to make a declaration that, “according to the most recent data at the end of the debates, Belgium has not respected or is no longer able to respect the objectives it had set itself with regard to the reduction of GHG emissions by 2020.”⁵⁹ They also requested that the Court make an injunctive order for the government authorities to reduce the annual GHG emissions from Belgian territory in order to obtain:

i)By 2025, a reduction of 48%, at least 42%, compared to 1990;

ii) By 2030, a reduction of 65%, at least 55%, compared to 1990;

iii) In 2050, net zero emissions.⁶⁰

Finally, the claimants requested that the Court order the government authorities to pay a penalty payment of one million euros for each month of delay if they fail to comply with the requests above.

In 2021, the Brussels Court of First Instance issued its judgment.⁶¹ It confirmed that Klimaatzaak and the individual co-claimants had standing to bring the claim. The Court found that the Belgian Federal Government and the three regional governments were jointly and individually in breach of their duty of care under the Civil Code. Despite being aware of the risks of dangerous climate change to the country’s population, the authorities failed to take necessary action, meaning that they did not act with the prudence and diligence required by Article 1382 of the Belgian Civil Code.⁶² Further, and by failing to take sufficient climate action to protect the life and privacy of the claimants, the defendants were in breach of their obligations under Articles 2 and 8 of the ECHR.⁶³

However, due to separation of powers considerations, the First Instance Court declined to issue an injunction ordering the government authorities to set the specific emissions reduction targets requested by the claimants.⁶⁴ The Court also found that neither European nor international law required the specific reduction targets requested by the claimants, and that the scientific report that they relied on was not legally binding.⁶⁵

In 2023, the Court of Appeals of Brussels issued its judgment and confirmed many of the First Instance Court’s findings.⁶⁶ In relation to the ECHR, the Court held that the Belgian Federal Government, the Flemish Region and the Brussels-Capital Region (but not the regional government of the Walloon Region) had breached Articles 2 and 8 of the ECHR.⁶⁷ The key basis of the Court’s findings was that the authorities’ emissions reduction targets for 2020 and 2030, and their actions to date to achieve their targets, were not consistent with minimum thresholds evident from scientific and political consensus. In this regard, the Court found it significant that:

i)In respect of the 2013–2020 period, the relevant authorities did not revise

their 2020 emissions reduction targets up to 30% (compared to 1990 levels) in line with scientific and political consensus at the time, and failed to achieve an emissions reduction of 30% by 2020;⁶⁸ and — S. 148 —ii) In respect of the 2021–2030 period, the Court concluded that a 55% reduc-

tion target by 2030 (compared to 1990 levels) at the Belgian State level is the “the minimum accepted by the best available science, if the Belgian State is to do its part” to prevent the dangerous threshold in terms of global warming from being crossed,⁶⁹ to comply with Articles 2 and 8 of the ECHR.⁷⁰

The Court then went on to assess whether the government authorities complied with their duties under the Belgian Civil Code, cross-referring to its analysis and findings from its assessment of the ECHR. The Court found that the Belgian Federal Government, the Flemish Region and the Brussels-Capital Region breached Articles 1382 and 1383:

i)In the 2013–2020 period, for the same reasons outlined in its assessment

of the ECHR.⁷¹

ii) In the 2021–2030 period, insofar as the upward revision of Belgium’s cli-

mate ambitions for this period was late and, to date, the policies being actually implemented are not likely to achieve the target of reducing GHG emissions by 55% by 2030 (compared to 1990 levels).⁷²

The Court also confirmed that the authorities’ positive obligations under Articles 2 and 8 of the ECHR acquired a “sufficiently definite content,” which meant that their breach alone constitutes a fault within the meaning of Articles 1382 and 1383 of the Belgian Civil Code.⁷³

Ultimately, and for the first time globally since the Dutch courts’ decisions in Urgenda, the Court issued an injunctive order that included a specified minimum emissions reduction target that must be met in order for the Government to fulfill its legal obligations. In this case, the Court ordered the Government to achieve a reduction of 55% by 2030 (compared to 1990 levels).

The Court determined that it did not have enough evidence at the time of the judgment to conclude with sufficient certainty that the effectiveness of the order would require penalty payments. The Court decided to postpone its decision on the penalty payment requested by the claimants, pending an evaluation of the government authorities’ emissions reduction performance between 2022 and 2024 (once data becomes available), as well as Belgium’s — S. 149 —updated National Energy and Climate Plan (NECP).⁷⁴ Zakia Khattabi, Belgium’s then-Minister of Climate, Environment, Sustainable Development and Green Deal, explained that she “was already convinced that we need to strengthen and speed up federal climate policy” but the Court of Appeal’s ruling “turn[ed] that conviction an obligation.”⁷⁵

b.The Wider Impacts of the Case

At the time of writing, Belgium has not made any formal announcements with respect to updates or changes to its climate policy. Accordingly, the Government is still failing to deliver on its existing emissions reduction targets, which the Brussels Court of Appeal deemed unlawful.

On 23 February 2024, the European Commission released its recommendations in respect of Belgium’s NECP.⁷⁶ EU Member States must develop and submit NECPs under EU law. These are the main policy documents setting out national plans and measures to jointly achieve emissions reductions and energy-related targets at the EU level.

The European Commission found that there was a “projected gap of 4.4 percentage points to meet the national greenhouse gas target of —47% in 2030 compared to 2005 levels under the [Effort Sharing Regulation].”⁷⁷ It also recommended that Belgium “[p]rovide updated projections to show how the existing and planned policies will deliver on the target” and “[c]omplement the information on the policies and measures, clearly spelling out their scope, timeline and, where possible, expected greenhouse gas reduction impact.”⁷⁸

At the time of writing, it is premature to assess the final policy impacts of Klimaatzaak. While the Brussels-Capital Region and the federal government both decided not to appeal the Court of Appeal’s judgment, the Flemish Region filed a cassation appeal with the Belgian Supreme Court in April 2024.⁷⁹ The decision to appeal the case has likely had a negative effect on the Belgian federal government’s ability to implement the Court of Appeals’ order, as collaboration between all three government regions is needed to achieve economy-wide emissions reductions. This is evident from the fact that the — S. 150 —Belgian government failed to submit an updated NECP to the European Commission by a 30 June 2024 deadline and, as of February 2025, has still not satisfied this legal requirement.

However, in terms of indirect impacts, the campaign accompanying the case has had a considerable impact within Belgium. The Klimaatzaak organization was founded by a group of 11 concerned citizens in 2014.⁸⁰ Five years later, when the Brussels Court of First Instance began proceedings on the merits, over 58,000 people had joined the lawsuit against the Belgian Government, making Klimaatzaak the largest climate case in history in terms of the number of claimants involved. The advocacy campaign, which heralded the case as “[t]he lawsuit in which everyone wins,”⁸¹ helped mobilize people in more than 100 municipalities and cities across Belgium during oral proceedings, including an estimated 7,000 supporters who took to the streets dressed as lawyers.⁸² Less than four months after the positive first instance ruling, a reported 70,000 people participated in a climate march in Brussels.⁸³ Such figures reflect a remarkably widespread engagement with climate change issues over a sustained period of time.

5.Discussion of the Impact of the Case Studies and Conclusion

The landmark cases described above are three of the most well-known climate litigation cases to date. However, success in this rapidly evolving field takes many forms. This section will rely on Urgenda, Neubauer and Klimaatzaak to explain how climate litigation is more than a zero-sum game, but rather a complex landscape where claimants can enhance progress even in the absence of a positive legally binding judgment.

In terms of direct impacts, the Urgenda, Neubauer and Klimaatzaak cases are success stories in that they showcase the ability of courts to demand from governments ambitious climate mitigation action (eg setting minimum emissions reduction targets, revising intermediate reduction targets, etc), while — S. 151 —also providing public authorities with ample room to determine precisely how to meet those obligations.

Regarding normative development, all three cases addressed key issues that have been a consistent theme in framework cases around the world, including the following:

—That states have a human rights obligation to take climate action, whether

under constitutional or regional law.⁸⁴ Notably, the ECtHR’s finding in KlimaSeniorinnen that Switzerland has a positive obligation under Article 8 ECHR to adopt and apply regulations and measures capable of mitigating climate change is now applicable to all 46 Council of Europe Member States.⁸⁵

—In framework cases concerning the adequacy of governments’ emissions

reductions targets that have proceeded to be heard on the merits, courts have had to consider the minimum level of action that governments must take to comply with their legal obligations. The principle of CBDR-RC, which is enshrined in the UNFCCC⁸⁶ and the Paris Agreement,⁸⁷ has been an important consideration for courts that are considering the targets adopted by developed nations. This principle was taken into account in Urgenda,⁸⁸ Neubauer⁸⁹ and Klimaatzaak⁹⁰ in terms of the Courts’ assessment of the governments’ respective legal obligations.

—The Court’s assessment in Klimaatzaak of Belgium’s mitigation efforts

under the 1.5°C long-term temperature limit of the Paris Agreement demonstrates how legally binding judgments can further normative developments related to best available science. The Court of Appeal’s analytical approach is noteworthy as it marked the first time a court in a government framework case substantively relied on the 1.5°C threshold to determine its decision.⁹¹

—In many framework cases, governments have sought to rely on the “drop

in the ocean” argument to shield themselves from liability. Governments have argued that no single state can be held legally responsible for the — S. 152 —global phenomenon of climate change because no single state is factually responsible for all of the harm or able to solve the problem alone. Courts have overwhelmingly and expressly determined that states cannot rely on this argument, including in Urgenda,⁹² Neubauer⁹³ and Klimaatzaak.⁹⁴

—Many states have failed to set out effective pathways to reach their re-

spective 2050 net-zero targets.⁹⁵ Instead, they propose modest short-term emissions reduction targets (such as by 2030), followed by markedly more ambitious targets in the lead up to 2050.⁹⁶ Both Neubauer and Klimaatzaak have addressed this issue, explicitly stressing that governments cannot postpone climate measures such that potentially drastic emissions reductions are needed in the future, as this inaction would disproportionately place the onus on younger generations.⁹⁷

Once one or more courts have tackled normative issues, such as those above, courts in other jurisdictions may look to those rulings as a guide and inspiration for their own cases. This is evident in all three of the case studies:

—The German Constitutional Court in Neubauer referred to the Dutch

Supreme Court’s decision in Urgenda numerous times when assessing issues such as (i) how current climate inaction potentially requires drastic future measures,⁹⁸ (ii) the inadequacy of adaptation measures to solely address climate impacts,⁹⁹ (iii) the risks of tipping points being crossed due to any increase in global temperature above 1.5°C¹⁰⁰ and (iv) with respect to the “drop in the ocean” argument.¹⁰¹

—Likewise, the Belgian Court of Appeal in Klimaatzaak referred to both

Urgenda and Neubauer in relation to the “drop in the ocean” argument.¹⁰² The Court also referred to Neubauer regarding its approach to best available science and the burdens that future generations would have to endure due to climate inaction.¹⁰³

—As a more recent example, Neubauer’s emphasis on CBDR-RC and equity

was expressly cited by the ECtHR in the groundbreaking Verein Klima-Seniorinnen Schweiz and Others v Switzerland case to stress the importance of national carbon budgets.¹⁰⁴ KlimaSeniorinnen also aligned with Urgenda and advanced the principle of CBDR-RC by emphasizing that each state must do “its part” to combat climate change.¹⁰⁵

Cases may also have impacts on normative developments that are more difficult to track. For instance, shortly after the Klimaatzaak decision, where 1.5°C was recognized explicitly for the first time as the relevant threshold for harm, both the ECtHR and the International Tribunal for the Law of the Sea relied on the 1.5°C temperature limit to reach their respective decisions in the Klima-Seniorinnen case and the historic Advisory Opinion on climate change and marine protection.¹⁰⁶ Although it is not possible to determine the precise extent that Klimaatzaak may have influenced these latter approaches, it is likely that the case helped raise the normative threshold of the climate ambition expected of governments.

In terms of indirect impact, all three cases achieved a huge amount outside of the courtroom. In all three cases, there was notable public mobilization as a result of campaigns accompanying the cases, which has led to wider public awareness and pressure on the governments to update their approach to climate action. As outlined above, both the Urgenda and Neubauer cases led to significant change to governmental policy in the direct aftermath of the judgments.¹⁰⁷

Focusing on Klimaatzaak, even if the Belgian Supreme Court were to overturn the Court of Appeal ruling, that negative outcome would not wipe away the positive indirect impacts ushered forward by the lower court decisions, notably the associated advocacy campaign and the decade-long level of public engagement with climate change issues.¹⁰⁸ Moreover, as the Klimaatzaak — S. 154 —organization has already provided inspiration to organizations pursuing government framework lawsuits in other jurisdictions, its influence on the larger climate litigation field has already been secured.¹⁰⁹

The relevance of considering the indirect impacts of a case becomes clearer when examining the ten model scenarios. These scenarios feature a range of progressive legal arguments and remedial requests, and new climate litigation ground would be broken if any of the claimants prevail on the merits and receive their desired remedy. The novel nature of these scenarios, however, leaves open the prospect that some, or all, of the cases could fail at various stages of adjudication. Given the time, personnel and financial demands required of such efforts, evaluating their effectiveness solely in terms of positive judgments would reduce the lawsuits to a high-stakes, binary endeavor. Fortunately, as the Klimaatzaak case indicates, it is not necessary to interpret climate disputes and their respective outcomes through such a narrow lens.

A closer look at scenario 3, as a representative example, provides further insight into how it is possible to brand a climate case as a success despite it failing on the merits. This scenario involves a group of farmers seeking redress against a national government before domestic courts for climate-related impacts in violation of their right to property under Article 1, Protocol No 1 of the ECHR. Certainly, the claimants in this case would hope for a positive judicial ruling, but such an outcome may be difficult to achieve given that an Italian district court recently ruled a government framework case (which concerned the Italian civil code and considered the state’s obligations under Articles 2 and 8 ECHR) nonjusticiable, despite the landmark jurisprudence established by Urgenda and Klimaatzaak.¹¹⁰

Accordingly, success in this scenario should be viewed in relative terms, as opposed to absolute ones. For example, if the Italian courts were to grant the claimants standing, but ultimately rule against them on the merits, the — S. 155 —outcome would signal an evolution in climate litigation and likely inspire new cases within Italy and in other jurisdictions. Similarly, campaigners, activists and scholars would justifiably proclaim that the domestic court’s ruling indicates a new willingness on the part of the Italian judiciary to consider climate change arguments. Finally, learnings from this case would serve as a basis to improve the prospects of success in future cases across Europe.¹¹¹ These representative indirect impacts illuminate the broad scope of success that climate litigation cases can take, even in the face of a negative judicial outcome.

As a final consideration, it is important to recognize some of the limitations of framework cases, and the inherently iterative nature of litigation as a tool to achieve change. A single case is unlikely to serve as the “silver bullet” to ensure all government action will comply with its obligations in the future — additional cases will almost certainly be needed to continue to uphold the standards that have been established in an initial case.¹¹²

For example, Urgenda focused on the state’s 2020 mitigation action. However, five years after the Supreme Court decision in Urgenda, Greenpeace Netherlands and eight Dutch citizens of the island of Bonaire filed a new case against the Dutch State, in respect of its mitigation and adaptation ambition.¹¹³ The case claims that the government’s law and policies are not aligned with 1.5°C and need to be significantly overhauled in order for the government to comply with its legal obligations under both tort and human rights law. Initial success, such as in Urgenda, may set the legal framework for future cases to be brought that can continue to hold governments accountable for their action going forward. However, to do so, new cases must be brought that reflect the current realities of government action, as well as the latest best available science and evidence. This requires similar levels of time and effort to an initial case on the part of plaintiffs, to ensure that governments are continuously being held accountable.

Similarly, although there is no doubt that the Neubauer decision set a critically important precedent in framework climate litigation, international political and scientific consensus has continued to develop. For example, the Constitutional Court relied on the German scientific advisory body’s findings in relation to Germany’s remaining carbon budget for 1.75°C, rather than 1.5°C. Independent analysis since the decision has found that even Germany’s new policies are not aligned with 1.5°C — and would lead to 2°C–3°C of warming if all countries were to set targets of an equivalent fair share level of mitigation.¹¹⁴ These shortcomings are now the subject of follow-up cases. In 2022, nine claimants from the Neubauer case filed a lawsuit in the German Federal Constitutional Court claiming that the reduction path in the revised KSG continues to infringe their fundamental rights.¹¹⁵ The Court refused to hear the case and it is now pending before the ECtHR.¹¹⁶ Furthermore, a recent federal amendment that has “substantially weakened” the KSG has sparked a new wave of climate lawsuits.¹¹⁷ In particular, between July and September 2024, several German environmental organizations (including BUND, DUH, Greenpeace and Germanwatch) and thousands of individual plaintiffs (including some of the applicants from the Neubauer case — such as the lead claimant Luisa Neubauer) announced a series of constitutional complaints against the German Government, arguing, inter alia, that the revised KSG is not ambitious enough to protect people’s fundamental rights and freedoms.¹¹⁸ These developments illustrate that the notion of success may evolve over time, and that litigation can form a strong basis for iterative improvement — and scrutiny — of government mitigation action.

In Klimaatzaak, even a year after the judgment, the direct impacts of the case are difficult to identify. This may partially be due to the fact that the case is yet to be heard in the country’s apex court, and regional governments may be reluctant to initiate extensive policy changes if there is a chance that the Court of Appeal decision will be overturned. The case has now been proceeding through the Courts for over ten years, and full compliance with the lower — S. 157 —Court’s orders may not be forthcoming until the case reaches its final conclusion. This illustrates another key risk of framework litigation — although plaintiffs have the potential to secure binding results, the nature of litigation means that cases could take many years to progress through all levels of the court system.

In light of the impacts associated with the case studies in this chapter, it is clear that success can be measured in a myriad of ways, from increased public awareness of climate issues to the enhanced ability of civil society organizations to discuss legislative and policy reforms with public authorities. All three cases had varying levels of direct and indirect impacts, which were complementary and generally positive in respect of galvanizing governmental action. By zooming outward and interpreting those outcomes in a more holistic manner, one can better understand how climate litigation can initiate meaningful change in a variety of ways. Moreover, the limitations of single cases illustrate the nuances of climate litigation as an effective tool for large-scale change. Ultimately, the success of a case is inherently linked to the understanding that it can and, ideally, should have both direct and indirect impacts, and must be used iteratively to generate lasting long-term results.