The practice of collaboration

Since 2005, lawyers, activists, plaintiffs, communities, NGOs and scholars have engaged in sustained and growing efforts to support, promote and enhance the use of human rights litigation to tackle climate change across legal systems. Over time, these formal and informal behaviors and interactions have given rise to a practice of collaboration. This consists of the performance of actions such as providing funding or organizing meetings and the development of intersubjective standards that shape how practitioners understand the meaning and ethics of transnational collaboration. There are three main ways in which collaboration has been practiced, specifically capacity-building, joint advocacy and community-building.

Actors in the field of RBCL have provided different forms of capacity-building that have addressed the gaps in material and ideational resources that can hinder the initiation of cases. Several NGOs and philanthropic foundations have provided funding that has enabled affected communities and lawyers operating with limited resources to build, file and promote rights-based cases in numerous jurisdictions (Interviews 10, 24, 25, 33, 34, 42 & 91). Many lawyers and campaigners we interviewed told us about their efforts to assist others in fundraising for a new or ongoing case or about having received such assistance from others in this field who had more fundraising experience or contacts (Interviews 12, 43, 51, 55, 56 & 80). In addition to funding, NGOs and practitioners in this field have provided training and other forms of technical assistance to support the filing of rights-based climate cases in other jurisdictions. This assistance ranges from the dissemination of knowledge and resources to advising on legal strategy, the selection of expert witnesses, the presentation of climate science and the design of public and grassroots communications campaigns (Interviews 28, 31, 34, 120, 131 & 133). For instance, a lawyer working for an international NGO shared with us how her organization facilitated knowledge-sharing and strategy development:

This collaborative approach to capacity-building has been crucial in enabling cases to be brought forward, particularly in resource-constrained contexts (Interviews 12, 31, 120 & 131). As one campaigner who benefited from the technical assistance offered by the Climate Litigation Network (CLN) testifies, “[their] help was enormously valuable both in tactics and in the legal issues” (Interview 30), with another declaring that “we would never have been able to bring this case had it not been for Urgenda in the Netherlands” (Interview 35). In addition, NGOs and affected communities have participated in collaborative communications campaigns aimed at promoting certain cases, disseminating their legal arguments or shaming states for opposing rights-based climate lawsuits (Interviews 15, 34 & 38). Lawyers and NGOs engaged in these cases have frequently submitted an amicus brief in support of cases initiated in another jurisdiction (Interviews 119, 120, 131 & 133). Given the limited resources and word counts at the disposal of the plaintiffs, the submission of amicus briefs can play a key role in bolstering the legal arguments brought by the plaintiffs in a case (Cichowski Reference Cichowski2016). In RBCL, human rights experts and NGOs have filed amicus briefs specifically to “make the human rights case for [plaintiffs] stronger” (Interview 67).

Lawyers and activists based in different jurisdictions have regularly collaborated with one another to develop and file new rights-based climate cases (Interviews 6, 25, 132 & 133). The first rights-based climate case, the Inuit petition, is the product of a collaborative effort between two American NGOs, a prominent Inuit activist, Sheila Watt-Cloutier and a lawyer based in Nunavut (Watt-Cloutier Reference Watt-Cloutier2015). Joint advocacy can also take place within a larger NGO, whereby a team of lawyers specializing in RBCL will cooperate with the members of their local branch (Interviews 120 & 127). As a youth campaigner points out, the resulting partnership often benefits both parties: “I don’t think the lawsuit would have been as successful if they would have done it alone because [we] have something that [they] don’t have and that is that it is a grassroots membership-based organization with people under the age of 25 [who served as plaintiffs in the case]” (Interviews 10, 15, 29 & 30).

Finally, actors in this field have developed community-building initiatives dedicated to supporting and advancing rights-based climate lawsuits. Initiated by the Urgenda Foundation in 2015, the CLN aims “to support climate cases worldwide” following the Foundation’s own historic victory before the Dutch courts (Urgenda Foundation 2024). On the other side of the Atlantic, Our Children’s Trust (OCT) is a public interest law firm that has filed youth-led climate litigation in the United States and supported “locally-led partner efforts by providing legal, outreach, and communications assistance and expertise” at a global level (Our Children’s Trust (Youth v. Gov) 2024b). Further, environmental NGOs have created teams and networks dedicated to rights-based climate justice, including Greenpeace International (Interviews 18 & 120), Client Earth (Interviews 13, 27, 34 and 38) and De Justicia (Interview 119). The most prominent rights-based climate cases have all been developed and filed in collaboration with at least one global organization or network (Interviews 15, 18 & 32). The importance of these networks is underscored by many of our interviewees, such as a lawyer reflecting on the success of a landmark case in which they were involved as an independent expert:

Even if the initial case itself is not developed in collaboration with key actors, the filing of a case often serves as an opportunity for lawyers and activists involved in local cases to build ties with the people and organizations at the heart of these transnational communities of practice (Interviews 21, 41 & 120).

In addition to these established networks and programs, community-building is practiced through routine, informal relational processes that occur across organizations and cases. Lawyers, activists and scholars have regularly interacted with one another through cooperation on specific lawsuits (Interviews 14 & 15) and meetings held with the express purpose of bringing people together to brainstorm, build capacity and foster collaboration (Interviews 40, 119, 132 & 133). These get-togethers are usually closed-door to allow for sharing of confidential or otherwise sensitive information about ongoing or potential litigation, to allow participants to know “who is doing what” and “ensure everyone is aligned” (Interviews 33 & 132). One of our interviewees, who works for an organization that filed a major international climate case, provides an example of such community-building efforts:

The practice of collaboration has contributed significantly to the spread of RBCL. Our findings suggest that resource and knowledge flows between the Global North and the Global South, as well as within and across regions, have facilitated the rapid transnational diffusion of this litigation (Interviews 18, 27, 31 & 106). Capacity-building initiatives, such as funding, technical assistance and training provided by NGOs and networks, have played a crucial role in enabling activists and lawyers globally to develop and file rights-based climate cases. This aligns with the broader literature on climate litigation in the Global South, which has emphasized the significance of transnational support and expertise in overcoming resource constraints and legal barriers in the Global South (Urgenda Foundation, n.d.). At the same time, our findings confirm Peel and Lin’s (Reference Peel and Lin2019) suggestion that these cases also benefit from partnerships with local NGOs, academics and lawyers (Interviews 59, 71, 72 and 75).

Yet the practice of collaboration does not only operate through an enabling pathway of influence. In fact, for many of the actors in this field, collaboration is explicitly about cultivating a shared sense of community. Capacity-building and joint advocacy initiatives can create transnational bonds between lawyers, activists and communities across cases – as one NGO lawyer explains: “there might be a law clinic in the US thinking about what is happening in Norway or a law clinic in Canada thinking about what is happening in the Philippines” (Interviews 34, 33 & 41). Some NGOs have convened meetings specifically aimed at fostering solidarity and a common purpose amongst activists and lawyers involved in RBCL in different jurisdictions (Interviews 15 & 34). The importance of such solidarity is highlighted by one of the petitioners in a landmark climate case:

Collaboration like this has created and deepened ties between lawyers, activists and experts in the fields of environmental law and human rights. This represents a significant change as human rights organizations had long been reluctant to work on climate change, while environmental organizations were initially cautious about the explicit use of human rights in their advocacy (Allan Reference Allan2020, 121–45; Interviews 33, 43 & 102). Environmental lawyers have thus sought out advice from key human rights lawyers to ensure that their cases don’t entail “something that could be adverse or set a bad precedent or get a finding that wouldn’t work” (Interview 120, 33 & 43).

At the level of ethics, several international lawyers and activists we spoke with highlighted the challenges of transnational litigation partnerships involving participants with differing resources, priorities and worldviews. An international lawyer supporting dozens of climate cases conveyed that “what we want is authentic litigation that is brought in the country that represents what the communities want, what is best for the society there” (Interviews 33 & 34). This emphasis on local leadership is increasingly shaping how collaboration is performed by lawyers, activists and communities and may eventually define not only what counts as ethical or unethical forms of collaboration but also transform the very meaning of collaboration as a practice, distinguishing it from what actors might define as exploitative relationships or arrangements.

The practice of storytelling

Lawyers, activists and plaintiffs have used RBCL as a vehicle to articulate and share stories about the climate crisis, its injustices and the role that human rights should play in response. In what follows, we analyze the four main narratives that have been articulated and reiterated through RBCL and explain how they have inspired lawyers and activists to bring different types of cases across multiple jurisdictions. The first narrative to emerge through rights-based climate lawsuits emphasized the adverse impacts of climate change on human rights and the disproportionate and uneven nature of the burdens borne by certain groups in the climate crisis. This narrative was first articulated in the petition filed by Inuit communities before the Inter-American Commission of Human Rights (IACHR) in 2005 (Jodoin et al. Reference Jodoin, Snow and Corobow2020). Drawing on the lived experience of Inuit communities on how global warming was disrupting their rights to life, safety, lands, and traditional cultures and livelihoods, the Petition argued that global warming threatened the “right to be cold” of Inuit communities in the Arctic (Watt-Cloutier Reference Watt-Cloutier2015). As one human rights activist explained to us, the petition “brought the human face to climate change to the forefront of peoples’ discourse” (Interviews 106 & 117).

This narrative has been reflected and reiterated in many of the rights-based climate cases launched during the past 17 years. A prominent example is from the Philippines, as shared by a lawyer representing affected communities:

As participants in the field, we have witnessed firsthand the power of this narrative in mobilizing affected communities and inspiring new rights-based climate cases. To bolster the storyline regarding the uneven impacts of climate change, these lawsuits typically include evidence that refers to climate science as well as testimonials of the concrete ways in which the climate crisis undermines the rights of the plaintiffs (Mathur et al. v. Ontario, 2020; Torres Strait Islanders Petition, Reference Billy2022). Emphasizing the disparate impacts of climate change on certain segments of the population, many of these cases argue that states must address climate change to respect and fulfill the right to equality protected under human rights law. Our systematic analysis reveals that approximately 44% of the cases in our dataset claim explicitly that climate change has disproportionately affected the rights of a particular group within society.

A second influential narrative stresses the disproportionate impacts of the climate crisis on children and youth and emphasizes their role and agency as activists fighting for intergenerational climate justice. This storyline was first articulated in a series of cases launched by OCT and is most closely associated with Juliana v. United States. In Juliana, 21 youth plaintiffs argue that the US government’s fossil fuel policies and inaction in the field of climate change infringe on their due process rights to life, liberty and property and are contrary to the government’s fiduciary duties under the public trust doctrine (Juliana v. United States 2020). Building on the first narrative, the Juliana case helped, in the words of a lawyer from the United States who was not involved in the case,

The story told in this case specifically emphasizes that young people have a fundamental right to a stable climate that is capable of sustaining life and highlights the intergenerational injustices associated with the climate crisis. The Juliana storyline of youth vulnerability and agency has been reflected in the extensive media coverage that it has generated in newspapers, radio, television and social media (Our Children’s Trust (Youth v. Gov) 2024a). Of the 1,008 articles referencing the Juliana case found in the Nexus Uni database of newspaper articles (Lexis Nexis Reference Nexis2024) from 2005 to 2022, 74% use the term “youth,” while only 11% refer to “climate science,” 14% use the words “human right” and 20% use the term “public trust.”

Coinciding with a period in which young people became increasingly active and visible in the climate movement, the narrative articulated in Juliana captured the imagination of many climate lawyers and has been recast in dozens of climate cases launched to protect the rights of children and young people from the current and future impacts of climate change around the world (Donger Reference Donger2022; Parker et al. Reference Parker, Jodoin and Wewerinke-Singh2022). Several interviewees shared with us that the story told in the Juliana case and the media coverage that it attracted inspired them to develop a climate case focused on the rights of young people (Interviews 5, 100, 119, 127 & 134). Our analysis reveals that 34% of rights-based climate cases have included youth and children as plaintiffs and conveyed in different ways the generational threats posed by the climate crisis. Youth-led lawsuits have not simply reproduced the narrative of intergenerational climate injustice first introduced by OCT; they have enriched it by recasting it in light of the lived realities of climate change for young people around the world and domestic legal norms and discourses.

In cases such as Ridhima Pandey v. Union of India (2019) and Mbabazi v. Uganda (2012), youth plaintiffs from the Global South have played a pivotal role in reshaping the discourse around climate change litigation. These cases are distinct not only for their emphasis on the experiences of young people but also for their focus on the unique vulnerabilities faced by youth in developing countries. What sets these cases apart is their explicit invocation of intergenerational equity, which underscores the ethical and legal responsibility to preserve the planet for future generations. While not directly targeting historical polluters, these cases may indirectly contribute to a more inclusive form of climate justice by highlighting how socioeconomic disparities exacerbate the vulnerability of youth in the Global South.

In the landmark case of Demanda Generaciones Futuras v. Minambiente (2018) the Colombian Supreme Court confronted the issue of deforestation in the Amazon, a matter with profound implications for Colombia and the global climate. The plaintiffs, a group comprising 25 young people, argued that the Colombian government’s failure to adequately address deforestation constitutes a direct threat to their fundamental rights to life, health and a healthy environment, as well as those of future generations. The Court’s ruling was groundbreaking in its express recognition of the rights of future generations in connection with climate change. By ordering the government to formulate and implement an “intergenerational pact for the life of the Colombian Amazon,” the Court not only emphasized the intrinsic value of environmental stewardship but also acknowledged the deep interconnections between human rights and environmental health (Demanda Generaciones Futuras v. Minambiente 2018). At the same time, this ruling sets an important precedent for incorporating the voices and rights of youth and future generations within the judicial processes addressing climate change.

In Neubauer, et al. v. Germany (2021), a group of teenagers and young adults argued that the inadequate emissions reduction target included in Germany’s 2018 Federal Climate Protection Act violated the principle of human dignity, the right to life and physical integrity and the constitutional duty to protect the natural foundations of life for future generations. The Federal Constitutional Court struck down parts of the German Federal Climate Change Act as incompatible with the youth plaintiffs’ constitutional rights and ordered the German government to adopt more ambitious emissions reduction targets for 2030. In its judgement, the Court recognized that Germany had a duty to protect life and health against the risks posed by climate change and was also obliged to preserve the freedom of future generations by not “unilaterally offloading” the burdens of reducing carbon emissions to future generations (Neubauer, et al. v. Germany 2021, 6). In doing so, the Court has extended the narrative of intergenerational justice to encompass not only the unequal burdens caused by climate impacts, but also those associated with having to adopt drastic measures to reduce carbon emissions in a shorter time-frame due to delayed and ineffective climate action.

A third transnational narrative to emerge from the field of RBCL stresses the legal obligation of governments to take action to reduce greenhouse gas emissions (GHG) GHG emissions in accordance with the recommendations of climate scientists. First launched in 2013, the Urgenda case argued that the failure of the Netherlands to reduce national GHG emissions to 25–40% below the 1990 level by 2020 violated its obligations under the European Convention on Human Rights (ECHR) as well as the duty of care it owed to its citizens under extra-contractual law (Urgenda Foundation v. State of the Netherlands 2020). While previous cases used science to establish that climate change threatened human rights and could be attributed to the conduct of states, the Urgenda case claimed that states were obliged to align their emissions reductions targets with the recommendations of climate scientists, as expressed in the reports issued by the Intergovernmental Panel on Climate Change (IPCC) (Paiement Reference Paiement2020, 140). In 2019, the Dutch Supreme Court determined that the Netherlands had indeed violated the rights to life and to private and family life, under Articles 2 and 8 respectively of the ECHR, by failing to take the necessary measures to reduce its GHG emissions and protect its population from the risks of climate change (Urgenda Foundation v. State of the Netherlands 2020).

The Urgenda narrative that states are obliged to reduce their GHG emissions in line with the dictates of climate science to fulfill their human rights obligations has been clearly reflected in this case’s media coverage. Of the 976 articles that refer to the Urgenda case in the Nexus Uni database of newspapers (Lexis Nexis 2024) from 2013 to 2022, we found that 100% of articles included the words “climate science,” 39% included the words “human right,” 26% included the word “accountable,” 30% included the word “duty,” 31% included the word “obligation” and 17% included the word “constitutional.” The Urgenda narrative has also been reproduced and strengthened through a wave of “systemic climate mitigation” lawsuits that “challenge the overall effort of a State or its organs (…) to mitigate dangerous climate change, as measured by the pace and extent of its GHG emissions reduction.” (Maxwell, Mead, and Berkel Reference Maxwell, Mead and van Berkel2022, 36) Our systematic analysis of RBCL shows that close to 40% of cases fall within this broad category and that 16% of cases focus specifically on the inadequacy of emissions reduction targets. Many of the interviewees involved with these Urgenda-like cases confirmed the role that this case played in promoting the story of state accountability for climate inaction and their intention to promote this narrative in their jurisdiction (Interviews 1, 123, 133 & 134). This narrative has been especially bolstered by the successful outcomes in Neubauer, et al. v. Germany (2021), Notre Affaire à Tous and Others v. France (2021) and Klimaatzaak v. Kingdom of Belgium (2023). Each lawsuit that advances a similar argument and each judgement that sides with the plaintiffs helps disseminate and translate the Urgenda narrative to a different political and legal environment and bolsters its credibility at a transnational level (Interviews 6, 7 & 134).

A more recent narrative to emerge from RBCL focuses on the responsibility of corporations in the climate crisis. In 2015, Greenpeace Southeast Asia, the Philippine Rural Reconstruction Movement, and a coalition of 12 NGOs and around 1,300 individuals petitioned the Philippines Human Rights Commission to open an investigation on the human rights impacts of climate change and the related responsibilities of global companies involved in the production of oil, natural gas, coal and cement (known as the “carbon majors”). The Commission accepted the petition in 2017 and released a final report in 2022 in which it found, among other things, that the carbon majors had contributed to 21.4% of global emissions had obfuscated climate science and delayed and hindered the transition away from fossil fuels and could be held accountable under Philippine law for having done so (Carbon Majors Decision 2022). Another prominent major rights-based corporate climate case was filed in the Netherlands in April 2019. Milieudefensie/Friends of the Earth Netherlands, seven other NGOs, and 1,700 citizens initiated a class action against Royal Dutch Shell for violating its duty of care to Dutch citizens by failing to reduce its GHG emissions and promoting climate disinformation (Milieudefensie et al. v. Royal Dutch Shell 2021). In a judgement rendered in May 2021 and that has been appealed, the Hague District Court held that Shell had a duty to prevent dangerous climate change under Dutch civil law and ordered the company to reduce its carbon emissions by 45% by 2030, relative to 2019 (Ibid., 44).

These two cases and the global attention that they have attracted from activists and journalists around the world have generated a transnational narrative that emphasizes that carbon majors can be held responsible for the human rights impacts of their contributions to the climate crisis (Interviews 3 & 6). This narrative has legitimized the notion of initiating human rights litigation against corporations for their role in causing the climate crisis. One lawyer we interviewed opined that the inquiry demonstrated that “a systemic shift should be in the play” (Interview 9) instead of, as another lawyer put it, “put[ting] the guilt on the individual” (Interview 3) as per the narrative that Shell and other fossil fuel companies had been promoting. Another lawyer highlighted the role of the Hague District Court’s ruling against Shell in helping “the public opinion understand [sic] that fossil fuel companies aren’t normal companies [because] they have a more severe impact and they have a more threatening product than any other company” (Interviews 1 & 56). For those directly affected by the adverse effects of climate change, the story told through the petition and the inquiry is empowering: as one of the petitioners explains, it “shows that even if you’re just a grassroots community … you can actually … challenge the big corporations for their business practices” (Interview 74). This makes the inquiry “very powerful, and not just for the Philippines, but for other vulnerable communities, because as we feel helpless, there is power in our vulnerability, there is power in our experience, there is power in our stories” (Interview 74).

We found that these four narratives have resonated with lawyers, activists and affected communities and have played a key role in inspiring them to launch new rights-based climate cases (Interviews 117, 119, 120, 123, 130, 131, 132, 133 & 134). As we discussed above, a broad array of lawyers, activists and affected communities have generated and internalized the storylines of human rights vulnerability, agency and accountability told through these cases. Discouraged by the failures and injustices associated with international and domestic policy processes in the field of climate change and in line with a broader discursive turn to climate justice (Beauregard et al. Reference Beauregard, Carlson, Ann Robinson, Cobb and Patton2021; Hadden Reference Hadden2015), many climate lawyers and activists have become persuaded of the appropriateness of mobilizing human rights law to address the impacts of the climate crisis, share and amplify the stories of those most affected by it and secure legal remedies to hold governments and corporations accountable (Interviews 102, 103, 105, 106, 107, 110, 111, 114, 116, 119, 120, 131, 132, 133 & 134). Each time a rights-based climate case has been filed, it has bolstered the credibility, legitimacy and salience of this transnational narrative and thus enhanced its appeal to lawyers, activists, policymakers, journalists and citizens. In addition to the number of cases, the breadth of jurisdictions to which this type of litigation has spread is also a key to bolstering the credibility of this narrative both in specific regions and as a global phenomenon (Interviews 7, 35 & 41).

The practice of storytelling also has an important enabling dimension. The stories told through these cases have provided a key resource that lawyers, activists and NGOs have used to promote rights-based climate cases, convince others of their feasibility and importance and attract support for their cases (Interviews 9, 35 & 41). Indeed, the potency of the narratives associated with human rights has led many climate activists to realize “that it is also a powerful tool, not only a legal tool but a powerful political and moral tool to gather a social movement around the case” (Interviews 4, 9, 10 & 25). By focusing on the human impacts of climate change, rights-based climate narratives have help bring human rights lawyers, activists and NGOs to the climate justice movement (Allan Reference Allan2020; Interviews 102, 103, 105, 106, 107, 110, 111, 114, 116, 119, 120, 131, 132, 133 & 134). This expansion has increased the transnational pool of potential allies, funding, information and expertise that are known to make legal mobilization more likely (Andersen Reference Andersen2006; Aspinwall Reference Aspinwall2021; McCammon et al. Reference McCammon, Hearne, McGrath and Moon2017).

Finally, storytelling has increasingly supported the diffusion of rights-based climate cases through relational processes of mutual influence. As additional cases have been filed, positive judgements have accumulated and related campaigns and media coverage have flourished, the decision to mobilize human rights to address the climate crisis has increasingly been driven by acculturation (Hadden and Jasny Reference Hadden and Jasny2017; Wang and Soule Reference Wang and Soule2012). As a Norwegian campaigner puts it, there are now “lots of cases which I think have all been inspiring us and telling us that we are not alone in doing this” (Interviews 14, 35 & 38). While it is difficult to distinguish processes of persuasion from those of acculturation in a single case, the increased frequency of cases of RBCL over time (see Figure 1 above) and the patterns through which certain types of cases are proliferating are consistent with the hypothesis that relational pressures are beginning to play a role in the diffusion of lawsuits and arguments at the intersections of human rights and climate justice.

Figure 1. Worldwide Google Trends data for Urgenda and Juliana v. United States, 2013–2020.

The practice of learning

Lawyers, activists, communities and scholars have facilitated and engaged in learning processes of different kinds in the field of RBCL. They have regularly exchanged, coproduced and disseminated information on the status of cases and ideas regarding legal arguments, the significance and use of climate science and strategies inside and outside the courtroom (Interviews 18, 132 & 133). In particular, numerous in-person and online meetings have brought together lawyers, activists and scholars to discuss, share and generate best practices for putting together different types of rights-based climate cases (Interviews 34, 132 & 133). In addition, the litigators and scholars working in this area have also produced a growing body of applied scholarship that explicitly aims to draw lessons from different cases and offers practical recommendations for effectively launching rights-based climate cases (Bähr et al. Reference Bähr, Brunner, Casper and Lustig2018; Maxwell et al. Reference Maxwell, Mead and van Berkel2022).

The media coverage of these cases, social media content and existing relationships and networks active in the fields of human rights or climate change have also fostered opportunities for spontaneous learning. For instance, some of our interviewees shared that they first learned of the success of the Urgenda case by reading media coverage (Interviews 20, 123, 130 & 134). To maximize opportunities for this sort of transnational learning, lawyers and activists have actively promoted their cases by soliciting traditional media coverage, writing books, participating in documentaries, presenting their cases at conferences and meetings organized by civil society, academic institutions and multilateral institutions, sharing their legal documents, often with unofficial versions translated in English, through electronic communications and websites; and generating social media on multiple platforms (Interviews 1, 100, 118, 120, 131, 132 & 133).

Figure 1 below illustrates the online impact and effectiveness of these strategies for two key climate cases over time. Using Google Trends data,Footnote ⁴ we were able to capture worldwide online search interest in Urgenda (represented by the orange line) and Juliana v. United States (represented by the blue line) from 2013 (the year the Urgenda case was filed) to the end of 2020 (the year that courts in both cases rendered key decisions). This figure evinces the growing interest in these cases during this period as well as the key moments where their search popularity spiked, which coincide with the dates when these cases were filed and when courts rendered decisions. Although levels of interest in Urgenda and Juliana declined between key legal milestones, they nonetheless attracted a sustained level of interest among journalists, climate lawyers and activists and the public at large.

The practice of learning has played a key role in supporting the diffusion of RBCL around the world. A clear marker of the influence of learning is the evidence of the dissemination of specific arguments advanced in pivotal cases. In our systematic analysis of cases, we found that 16% of cases explicitly focus on insufficient emissions targets, a type of argument that first originated in the Urgenda case, and 10% of cases specifically invoke the public trust doctrine, an approach that has been popularized through the Juliana case and promoted by OCT. In fact, the influence of these two cases is greater than these numbers suggest. Urgenda has inspired cases that advance a broader argument relating to state accountability for human rights violations caused by climate change. Juliana has stimulated the development of cases involving youth plaintiffs. Beyond these two pivotal cases, we also found evidence that lawyers and climate activists have derived and applied lessons from the cases of Leghari (Interviews 13, 25, 35 & 41), Demanda Generaciones Futuras (Interviews 119, 25, 39 & 42), and Neubauer (Interview 134).

Transnational earning in the context of transnational processes litigation exerts influence through a complex combination of enabling, discursive and relational pathways. In purely rational terms, the practice of learning refers to the acquisition and strategic application of knowledge concerning the advantages and disadvantages of a particular legal strategy (Lopucki and Weyrauch Reference Lopucki and Weyrauch2010). Lawyers and activists will decide to launch a new case or adopt a particular legal argument based on the lessons they have construed about the success of legal cases and arguments brought elsewhere and their potential benefits for the pursuit of climate justice in their jurisdiction as they have been known to do across causes in the United States (Meyer and Boutcher Reference Meyer and Boutcher2007). With the exceptions of those who were involved in the pioneering cases of the Inuit petition, Juliana and Urgenda, all of the climate lawyers and activists we interviewed confirmed that other cases had played a key role in shaping whether and how to bring a rights-based climate case in their jurisdiction (Interviews 5, 7, 18, 20, 25, 119, 120, 123, 130, 132, 133 & 134). Learning consists here of an interpretive practice that can yield different results based on the context and purposes of the inquiry. For instance, climate lawyers have drawn different lessons from the legal arguments advanced in Urgenda, focusing on how to: link human rights and climate inaction (Interviews 18, 28 & 33), invoke the duty of care in the context of climate inaction (Interviews 1, 3, 4, 20, 29 & 41), challenge the insufficiency of emissions reductions targets (Interviews 19, 31 & 32) or plead climate science and address issues of causation (Interviews 4, 7, 27 & 134). The significant influence of the Urgenda and Juliana cases on the development of subsequent cases is confirmed by our own observations and experiences in the field, with many litigants and activists with whom we have worked explicitly citing these cases as sources of inspiration and learning.

The proliferation of rights-based cases over time has provided opportunities for lawyers and activists to draw and combine lessons from multiple cases. The practice of learning from the Urgenda and Juliana cases has even translated into different types of lawsuits in the same jurisdiction. In Canada, two groups of lawyers and activists were inspired by Urgenda to launch similar challenges to emissions reduction targets (Environnement Jeunesse c. Canada 2019; Mathur v. Ontario 2020), while another group launched a Juliana-style youth-led lawsuit specifically invoking the public trust doctrine (La Rose c. Canada 2023). Meanwhile, many climate lawyers have cited both Urgenda and Juliana as sources of inspiration for developing climate lawsuits (Interviews 119 & 134), and there are many cases that draw on elements of what was understood to be successful about both cases (Environnement Jeunesse c. Canada 2019; Mathur v. Ontario 2020).

While some lawyers appear to believe that lessons about law and litigation are easily transferable across legal systems (Interviews 2, 22 & 31), we found that learning has generally been practiced in a careful manner that has resulted in the translation of legal arguments, rather than their transplantation, across jurisdictions. Aware of the risks and downsides of the mechanical replication of cases, lawyers have generally adjusted legal arguments inspired by other cases to fit with the local legal and political realities of their jurisdictions (Interviews 133, 134 & 135). As one interviewee put it, “internationalization is very important but also context-specific; there is no one-size-fits-all approach” (Interviews 27, 31 & 33). Several interviewees thus stressed the importance of assessing and adapting legal strategies in light of prevailing legal norms (Interview 31), explaining, for example, that the legal arguments invoked in cases such as Urgenda were less likely to convince judges within their own legal system (Interviews 15, 20 & 44). Unsurprisingly, we have found that similarities between different legal systems have indeed facilitated learning-driven diffusion. For instance, the Urgenda case has exerted greater influence in jurisdictions with civil law systems and in states that are parties to the ECHR (Interviews 119 & 133). The Juliana-style public trust cases, meanwhile, have largely been launched in countries that use the common law (Interviews 119 & 133). For a lawyer involved in a rights-based climate case before the courts in India, Ali v. Pakistan was particularly inspiring, in part because the case was seen as most relevant to the Indian context and because of similarities between the Indian and Pakistani legal systems (Interviews 20, 23, 39 & 41).

The discursive pathway in learning in the context of RBCL is apparent when we compare the different “lessons” that have been learned from the Juliana and Urgenda cases and the divisions they reflect in the broader field of transnational climate advocacy (Allan Reference Allan2020; Hadden Reference Hadden2015). Three key questions that have emerged in the field of RBCL concern the ways in which human rights should be plead, the selection of an acceptable target for average increases in global temperature and the means for pleading climate science. The Juliana and Urgenda cases take a different approach to these three questions, and their differing positions are reflected in the waves of cases that they have inspired. The Urgenda case and other similar cases generally argue that governments have violated their human rights obligations, their duty of care or an existing public law by adopting emissions reduction targets that are insufficient to ensure that global average increases in temperature remain well below 2°C and, if possible, 1.5°C, an objective that is enshrined in the Paris Agreement (Maxwell et al. Reference Maxwell, Mead and van Berkel2022). Moreover, Urgenda-like cases typically rely on the authoritative recommendations of the IPCC to establish this temperature increase as the acceptable level of climate change and to determine the emissions reduction targets that states must meet in order to prevent harm to the plaintiffs (Paiement Reference Paiement2020, 131–33).

By contrast, in Juliana-like cases, the plaintiffs argue that governments are infringing fundamental rights and breaching their fiduciary duties to preserve the atmosphere for current and future generations by not only failing to reduce carbon emissions but also because they are subsidizing the extraction and consumption of fossil fuels (Wood Reference Wood, Coghill, Smith and Sampford2013). These cases also argue that governments have an obligation to keep CO2 concentrations below 350 ppm and limit global warming to 1°C. This approach specifically rejects the 1.5°C limit adopted by the IPCC as a “safe target” for global temperature rise (Our Children’s Trust (Youth v. Gov) 2024c) (Our Children’s Trust (Youth v. Gov) 2024c) and thus relies on the scientific research of internationally renowned climatologist James Hansen rather than the reports of the IPCC (Hansen Reference Hansen and James2015).

The different approaches adopted in Urgenda and Juliana and the cases they have inspired are not mundane. They have significant implications for the cost and complexity of bringing a rights-based climate case, for their odds of being successful in court and ultimately for the type of climate justice they seek to advance. The practice of learning in RBCL is ultimately tied to the classic conundrum at the heart of public interest litigation. Is it better to adopt a strategy that has a greater likelihood of success but that may have fewer transformative outcomes (Interview 133)? Or is the pursuit of an incremental case simply a hollow hope that only legitimizes the existing system and the injustices that it reflects (Interview 131)? Although Urgenda is generally perceived as a success story that should be emulated, some climate lawyers are indeed critical of the approach taken by the plaintiffs and the outcomes reached in court (Interviews, 9, 20 & 32). Another climate lawyer shared with us that the targets adopted in the Urgenda case “baffles” them, explaining that “it just really hard for me to think about the duty to do no harm and duty to fully inform our plaintiffs about the difference between 1.5 degrees and 350 PPM” (Interview 131). In justifying their preference for more ambitious types of rights-based climate cases, this lawyer imparted that “all of these principles that are just embedded in my DNA, that’s what I deeply, deeply struggle with. Like I can’t go with practical if practical is going to result in people dying” (Interview 131). On the other hand, the cases that aim for transformative change also attract harsh criticism from other lawyers and activists. For these critics, a more strategic approach takes greater account of the risk of setting a negative precedent and involves closer alignment with existing litigation efforts at the domestic level (Interviews 7, 33 & 44).

A final important finding of our fieldwork is that the relational aspects of learning have been just as critical to the diffusion of RBCL as its strategic and discursive dimensions. Over and over, the climate lawyers and activists we interviewed emphasized that climate lawsuits and judgements had made them hopeful and inspired (Interviews 43, 100, 102, 119, 120, 123, 131, 132 & 134). As one climate lawyer explains, the decision to launch or support a climate case ultimately “stems from the fact that they can be part of a solution that just might work” (Interview 131). For petitioners, filing a case can be about having “grown tired of just being the victims” and “doing something [so that] we’re not just victims, we are getting the justice that we deserve” (Interview 74). Another lawyer described the take-away lessons from Juliana and Urgenda as “exciting, interesting ideas … because they were innovating and because they had shown that courts would be potentially willing to entertain some of those arguments and that, for example, representing young people sends a key communication or message that we wanted to convey” (Interview 119).

To be sure, the credibility of the lessons that can be gleaned from a case is enhanced whenever the plaintiffs are successful (or perceived to be so). There is no doubt that Urgenda’s success in the Dutch courts has played a key role as a source of learning about whether and how to bring a rights-based climate case (Interviews 19 & 20). As one climate lawyer summed up: “if you are starting your own case, you want to look at what worked elsewhere and immediately you bump into Urgenda” (Interviews 27 & 29). Likewise, a campaigner observed that “once it starts and is successful, which was the case with Urgenda … others will follow because we see it can be very effective” (Interview 29). Yet lessons can also be derived from unsuccessful cases and arguments too – climate litigators have, for instance, learned about the best way of demonstrating justiciability from lawsuits where this proved to be a stumbling block (Interview 134).

Moreover, even if they are unsuccessful in court, climate lawsuits can nonetheless serve as a source of inspiration and knowledge. Climate lawyers and activists have drawn lessons from other climate lawsuits about the best ways of generating media coverage and galvanizing public opinion (Interviews 25 & 131). Despite underwhelming results in the legal system, the Juliana case has exerted global influence, in part because of its success in attracting media and public attention (Interviews 119, 131 & 34), its resonance for a climate justice movement in which children and young people have played increasingly important roles and its commitment to an ambitious conception of climate justice.

The cumulative effects of practices on the diffusion of RBCL

While we have thus far treated each practice as distinct from one another, collaboration, storytelling and learning have been performed in an iterative manner by actors in the field of RBCL. This has had cumulative structural effects that have reinforced their impact over time. First, the intensification of collaborative practices in rights-based climate cases has generated increasing returns due to network effects (Bendell and Ellersiek Reference Bendell, Anne, Utting, Pianta and Ellersiek2012). It has widened the scope of the transnational network of lawyers, activists and scholars working in this area of law, resulted in a growing pool of resources and expertise that can be provided to support new cases, and increased the availability of allies to engage in joint advocacy (Interviews 4, 7 & 133).

Second, the cascade of RBCL has generated and sustained the transnational narrative concerning the adverse human rights impacts of climate change. Each time a new rights-based climate case has been filed, it has bolstered the credibility, legitimacy and salience of this shared narrative and thus enhanced its appeal to lawyers, activists, policymakers, journalists and citizens (Interviews 2, 4, 10, 29 & 35). The proliferation of different types of rights-based climate cases has provided opportunities to articulate and disseminate distinct narratives focusing on different aspects of the relationship between human rights and climate change. This has enhanced the prospects for the global diffusion of a broader narrative of rights-based climate justice (Jodoin et al. Reference Jodoin, Snow and Corobow2020; Paiement Reference Paiement2020). However, it may also be leading smaller communities of lawyers and activists to coalesce around narratives that reflect diverging epistemic and ethical commitments that may eventually hinder collaboration (Hadden Reference Hadden2015; Mason-Case Reference Mason-Case2019).

Third, the initiation of a growing and increasingly diverse number of rights-based climate lawsuits has enhanced learning by providing opportunities for actors to draw lessons that confirm, disprove or add nuance to the preexisting assessments of the effectiveness of different strategies (Interviews 133 & 134). The feelings of hope inspired by lawsuits can also increase as more cases are filed, and positive judgements accumulate. The diffusion of rights-based climate cases all over the world has helped inspire a sense of solidarity and collective optimism among lawyers and activists working at the intersections of human rights and climate justice. One lawyer involved in multiple cases explains that webinars that bring lawyers and plaintiffs together to share stories has led to “this beautiful connection” and a sense of “solidarity” (Interviews 34 & 5). Collective feelings of hope and solidarity can provide litigants with the sort of social support that is useful for managing political and public backlashes to their cases and handling the stress of litigation (Interviews 29 & 35).

Finally, collaboration, storytelling and learning have fostered the emergence of multiple overlapping communities of practice at the intersections of human rights and climate change. By facilitating socialization, co-generating shared narratives and creating and disseminating a common body of knowledge, these practices have engendered the formation of a loose community of lawyers and activists who are committed to using human rights litigation as a means of addressing the climate crisis (Interviews 1, 119, 120, 121, 132 & 133). Many interviewees shared their sense that they belonged to a transnational community of rights-based climate litigators, even if they disagreed with the specific types of arguments advanced in other cases (Interviews 119, 120, 123, 130, 131, 132, 133 & 134). At the same time, the practices of collaboration, storytelling and learning may also be giving rise to the emergence of smaller, more cohesive communities of practice that are held together by a common set of epistemic and normative commitments (Bartley and Smith Reference Bartley, Smith, Djelic and Quack2010). As was highlighted in our analysis of collaboration, storytelling and learning, distinct communities of practice appear to have coalesced around and been fostered by the CLN and OCT. (Interviews 27, 32 & 133). Because these communities can influence the development and flow of legal ideas, resources and partnerships, the stories that are told and amplified, and the lessons that are learned and shared, the potential consolidation of distinct communities of practice has ambivalent implications for the global diffusion of RBCL. Cohesive communities provide the possibility for deeper forms of socialization and acculturation among their members, but they also make conflict and competition between different communities more likely (Hadden Reference Hadden2015; Mason-Case Reference Mason-Case2019).