Polluters Beware: Mountain Guide Saúl Luciano Lliuya Proves That Major Corporate Emitters Can be Held Liable for the Future Effects of Climate Change
By Linn Pfitzner*, Abbi Hedges** and Joben Odulio-Camacho***
Introduction and Overview
While emissions are often produced by carbon majors based in places like Europe, these same emissions negatively impact the environment in such a way that communities thousands of miles away - across borders and continents - face severe threats to their lives and livelihoods due to a changing climate. The question therefore arises - what responsibilities do carbon majors have for future climate harms that may occur far from where their corporate emissions originate? This question lay central to the case of Saúl Luciano Lliuya v. RWE AG (“Saúl v RWE”), a groundbreaking climate lawsuit brought by Peruvian farmer and mountain guide Mr. Saúl Luciano Lliuya (“Mr. Lliuya”) against Germany’s largest power producer, RWE. Filed in 2015 with the support of the NGO Germanwatch, the claimant sought to hold RWE civilly liable for its contribution to global warming, which Mr. Lliuya argued had intensified the flood risk threatening his home in the Andean city of Huaraz.
Mr. Lliuya lives in Huaraz, a city nestled below the rapidly melting Palcaraju Glacier and Lake Palcacocha, an expanding glacial lake that sits more than 4,500 meters above sea level. The lake is blocked only by a fragile natural moraine or dam. It has a known history of deadly floods, including following an earthquake in 1941 that devastated the city, after an avalanche triggered a breach in said moraine. Despite a series of interventions by the people of Huaraz to prevent the lakewater from teeming into their city, the lake’s water volume has steadily increased in recent years, heightening the risk of catastrophic flooding. According to Mr. Lliuya, in the event of another breach of the dam, his home and his city would likely be submerged.
Before the German Court, Mr. Lliuya argued that anthropogenic climate change, driven in part by RWE’s emissions, is the primary cause of glacial melt in the region. Drawing on the Carbon Majors study, he calculated that RWE was responsible for approximately 0.47% (later in the proceedings altered to 0.38%) of global historic greenhouse gas emissions. On that basis, closely mirroring the transboundary harm principle first affirmed in inter-state litigation in the seminal Trail Smelter case, Mr. Lliuya asked the Court to order RWE to contribute a corresponding share of the costs of putting in place protective infrastructure against the fatal threat of flooding. His legal claim was based on Article 1004 of the German Civil Code, which governs general nuisance claims. Mr. Lliuya argued that the said provision applies to transboundary climate harms. By introducing this argument into the climate litigation arena, even simply by the case being initiated, Saúl v RWE already carved out a defining moment in the evolution of climate justice through the courts.
The Regional Court of Essen dismissed the claim in 2016, finding insufficient “legal causality”, though it acknowledged the scientific plausibility of a connection. However, Mr. Lliuya appealed.
In a historic move in 2017, the Higher Regional Court of Hamm (the “Hamm Court”) permitted the case to proceed to the evidentiary phase. This marked the first time a civil court in Europe admitted a climate damages claim brought by a Global South claimant against a Global North corporation. Over the following years, the Court conducted extensive fact-finding (subject to much debate and criticism by both parties), including a site visit to Huaraz in May 2022. Following hearings in Germany in March this year, the Court delivered its final ruling on May 28, 2025.
This blog post explores the legal and factual contours of the decision, its broader implications for corporate accountability, and how it connects to other efforts for climate justice, such as further domestic litigation or the recent Advisory Opinion from the International Court of Justice (ICJ) concerning the obligations of states in respect of climate change.
Regional Court of Hamm Makes its Decision - A Purely Superficial Win for RWE
The Reasoning of the Court
The lengthy legal process preceding the judgment in Saúl v RWE on May 28, 2025, attracted global attention from civil society and corporate majors alike. Although the case was admissible, it was ultimately declared unfounded. Nonetheless, the end to Mr Lliuya’s long legal battle is not as disparaging as claimed by the defendant, RWE.
The Hamm Court reasoned that, considering Article 1004 of the German Civil Code, there was not a sufficiently imminent threat to the claimant’s property to have permitted a finding of nuisance. Upon review of scientific evidence, the probability of damage actually occurring was no more than 1% over the next 30 years. Furthermore, the Court held that even this 1% figure was based on a number of assumptions which favoured the plaintiff, so in reality, the probability may be even lower. Notably, Saúl v RWE constituted the first case to authoritatively test attribution science in court, offering room for critical reflection both on the level of acceptance for climate models as evidence and their interpretation in the courtroom.
Beyond evaluating the likelihood of damage to the claimant’s property, the Court gave significant consideration to the time period over which the probability should be assessed. It ultimately settled on an interval of 30 years, whilst the plaintiff argued 100 years was more appropriate. The Court was of the opinion that the likelihood of a concrete and tangible danger could only be reliably estimated over a period of three decades because of the inherent uncertainty that the region faces - in terms of economic, geographical, and social developments. Any longer period could not be assessed with the requisite level of certainty and foreseeability.
A Loss in This Instance But a Win for the Fight Overall
The outcome before the Hamm Court certainly failed to deliver climate justice for both Mr. Lliuya and his community. Whilst the decision is final with no further possibility of appeal, the threat to their lives and livelihoods persists - they must continue to navigate this uncertain environmental future whilst the defendant, which ranks amongst the companies most responsible for climate change, can evade any tangible form of responsibility.
Unsurprisingly, the narrative that RWE is pushing is that of a broader and more resounding win against activist lawyers and NGOs, putting an end to future corporate climate litigation. However, in reality, this could not be further from the truth.
Digging deeper into the substance of the Hamm Court’s decision, it is clear that the Court actually handed down a very climate-positive, claimant-friendly decision. In fact, the decision elucidates principles which not only complement but could massively fuel future cases against major polluters in Germany and beyond.
Opening the Door for Holding Major Polluters Liable
Following the decision by the Hamm Court, German courts are in principle able to hold companies liable for future climate harms in damage-based civil claims. Crucially, this relates to the ever-present “political question” in global climate litigation whereby defendants continually argue that establishing liability for climate harm is for governments, not courts, to regulate. The Hamm Court resoundingly rejected this argument and emphasised the competence of German courts to address this topic.
This finding is pertinent given other major climate litigation cases such as the now concluded Shell v Milieudefensie in the Netherlands, and the ongoing cases of Greenpeace Italy and Others v ENI and Others (“Greenpace Italy v ENI”) in Italy and Asmania v Holcim in Switzerland (amongst many others). As the plaintiffs in Shell v Milieudefensie purely sought to establish emission reduction targets, the case’s direct comparability with Saúl v RWE may be limited. Nonetheless, the Court in Shell v Milieudefensie resoundingly confirmed that dealing with corporate climate issues was within the competence of the Dutch judiciary, as such in line with the reasoning of the Hamm Court in the present case. This question was also considered by the Italian Supreme Court in 2025 - and decided in favour of the claimants - in Greenpeace Italy v ENI (which seeks a declaratory judgment of liability and emission reduction targets) and will be considered in Asmania v Holcim (which seeks a declaratory judgment, compensation and emission reduction targets). These cases are discussed further below.
Transboundary Harm is Relevant to German Nuisance Claims
Another monumental finding of the Hamm Court is that transboundary harm can be a valid type of damage suffered in nuisance claims under Article 1004 of the German Civil Code. A claimant in a German court does not need geographic proximity to the defendant in order to bring a claim for (future) climate harms - as such, accountability for damage suffered in Peru can be litigated all the way across the Atlantic Ocean in Germany should sufficient causality exist.
This enormously important finding moves dramatically away from the traditional confines of domestic tort law. It opens the door for claimants from the Global South, often ignored in the climate litigation sphere, to pursue claims in the courts of the Global North (discussed further below).
Causation Defences May Not be an Insurmountable Hurdle in Corporate Climate Cases
As the threat of damage was not considered sufficient in this case, the Court did not definitively address the issue of causal link between RWE’s emissions and the harm (to be) suffered by Mr. Lliuya. As such, the Saúl v RWE case does not signal the end of the discussion of this issue and further developments are a given. Nonetheless, the Court did set out some very claimant-friendly considerations which will be very helpful to this assessment in future cases.
Notably, the Hamm Court emphasised that assessing the materiality of a contribution to harm in the context of multi-causal liability scenarios is a comparative exercise. This analysis is not an assessment of whether the percentage of the contribution as a crude and standalone figure is material, but whether it is material when compared to the contributions of others. In a massively positive move for climate litigation, the Court made clear that a contribution as low as 0.47/0.38% to global emissions between 1965 and the present by RWE could be considered material. The Court noted as relevant that all causal shares of the world’s biggest polluters are less than 3.6% and RWE ranks 23rd out of the world’s 82 biggest emitters. As a result, it will be much harder for polluters to argue that they are a small fish in a big pond when it comes to climate change.
Ignorance is Not Bliss: Climate Harms Have Been Foreseeable for Decades
Finally, in an enormously important statement regarding the foreseeability of harm, the Hamm Court explicitly held that major emitters - just like RWE - have known about climate harms from as early as 1958. Further, given the nature of their industry, they are undoubtedly obligated to continuously monitor scientific and technological developments in this sector. This means that companies like RWE cannot feign ignorance of the harms that their businesses have undeniably been causing to the world for decades, despite their continuing climate denial.
Saúl v RWE – Setting a Precedent for Domestic and International Climate Litigation?
Considering the landmark character of Saúl v RWE, expecting the judgment to reverberate across the European climate litigation landscape and beyond appears reasonable. Nonetheless, as a civil law jurisdiction, German law does not recognise the doctrine of precedent in the same manner as common law systems. As a consequence, courts are not formally bound by earlier rulings, irrespective of whether or not those originate from a higher court. Despite this, considering that the application of common legal principles to corporate climate accountability cases remains nascent, judicial reasoning in Saúl v RWE may carry significant persuasive weight for pending cases and those yet to be filed. Therefore, whilst the decision in Saúl v RWE is not binding on other domestic - let alone foreign - courts, it still represents a significant moment in the development of climate litigation with the potential for transboundary judicial impacts. To this end, it is imperative to consider that Saúl v RWE to date remains one of the very few cases globally in which a domestic court substantively engaged with a claim involving corporate liability for climate change pursued using a civil damages framework, and brought by a claimant from the Global South.
With this in mind, this section of the blog will now consider how both national and international courts may draw on the Saúl v RWE judgment when dealing with related cases.
Starting from the domestic level, the claimants and legal team in Asmania v Holcim will undoubtedly be carefully analysing the Hamm Court’s decision for learnings that may be relevant in the Swiss context, given significant similarities with Saúl v RWE. Just as in the present case, Asmania v Holcim is brought by Global South claimants against Global North defendants - fighting for a space in Global North courts for Global South claimants to address climate-related injustices. The Swiss case was brought by residents of the Indonesian island Pari against Holcim, a large Swiss building materials manufacturer and one of the world’s biggest polluters. Further, whilst not a nuisance provision, the Asmania case also relies on the novel application of a specific provision of national legislation to the climate context - so-called Swiss ‘personality rights’ which effectively translate human rights protections to the horizontal context.
Considering these similarities, the Asmania case may be both buoyed and deflated by the outcome in Saúl v RWE. On the one hand, the Hamm Court’s decision will add weight to arguments made in the Swiss Court - reinforcing that transboundary harm can be a valid form of damage in civil claims, and that cases brought by Global South claimants can be heard within European courts. Furthermore, the Asmania legal team will likely heavily utilise the Hamm Court’s statements regarding causation as a comparative exercise. It is clearly at least influential that the Hamm Court could envision causation being established in multi-causal contexts where the defendant’s contribution is as low as 0.38%. On the flip side, the judgment in Saúl v RWE will likely trigger the Asmania legal team to reconsider their arguments surrounding the likelihood of future harm to the residents of Pari and the associated attribution science. The low probability of flooding within the next 30 years posited by the Hamm Court was fatal for the claimant’s team in Saúl v RWE.
Despite these similarities, there are also differences between these cases. Namely, unlike Saúl v RWE, Asmania v Holcim does not purely seek compensation for the future costs of protective measures but combines this with damages for historic harm and the declaration of a legally binding emission reduction target of 45% by 2030 for Holcim. As such, the cases of Shell v Milieudefensie and other corporate framework cases may also be heavily influential in shaping the legal arguments and outcome of Asmania v Holcim.
Furthermore, albeit not a transnational climate case, ripples from Saúl v RWE may have already been felt across jurisdictions in cases like Greenpeace Italy v ENI. Following a hearing earlier this year, in July the Supreme Court of Cassation held that Italian courts do have the competence to litigate climate issues and the case will now proceed to the merits.
While Saúl v RWE is a domestic civil case against a private company, the judgment touches upon key questions regarding causation, transboundary accountability, and foreseeability, which have also received attention at the international level. Crucially, the ICJ considered these issues in its Advisory Opinion on climate change, delivered on July 23, 2025. Both the Hamm Court and the ICJ engaged with modern climate science to affix liability, adding significant weight to the argument that scientifically attributed shares of emissions are legally relevant for corporations and states alike. These important legal outcomes may reverberate across cases which blur the lines between state and corporate accountability. This holds true for Greenpeace Italy v ENI, as ENI’s co-defendants - its major shareholders - are Italian government bodies.
Furthermore, the general willingness of the Hamm Court to consider a German company accountable for harm in Peru reinforces that climate obligations possess a transboundary character, an argument now resoundingly affirmed by the ICJ. Finally, the judgment in Saúl v RWE, similarly to the recent Advisory Opinion AO 32/25 before the Inter-American Court of Human Rights (“IACtHR”), emphasises that major emitters have long been aware of the risks of climate change. It, thus, comes as little surprise that states feigning ignorance as to the connection between their (historic) emissions and climate impacts before the ICJ were similarly unsuccessful in this argument. Given the many synergies between the judgment in Saúl v RWE and the ICJ and IACtHR advisory opinions, together, these legal outcomes will undoubtedly add momentum to the growing enforcement of corporate and state climate responsibility in (inter)national courts.
Conclusion - A Hope for the Future of Corporate Climate Litigation
The outcome in Saúl v RWE is undoubtedly a blow for Mr. Lliuya and his community - and one which is acutely felt by climate activists around the world. Nonetheless, while this specific case may not have had the outcome many wished for, if we look deeper into the substance, it does provide much hope for future corporate climate litigation not only in Germany, but also in Europe and beyond. Many of the foundational findings of the Regional Court of Hamm are both groundbreaking and legally sound. There is hope that the ripple effect of this case will continue to be wide.
What is more, similar to the ICJ advisory proceedings, this case has given an invaluable voice to those often affected the most by climate change but under-represented in legal processes - Global South claimants. What is clear is that this will not be the last we hear from claimants in this important region, and it is time for the courts of Europe and the world to listen.
*Linn Pfitzner is an editor for WYCJ’s Legal Blog and a PhD candidate at the University of Edinburgh, having previously obtained their LLM in Global Environment and Climate Change Law. They have worked on climate policy at the European Parliament and GIZ, with current research interests including intergenerational fairness and legal approaches to non-economic loss and damage.
**Abbi Hedges is an English and Welsh law solicitor and holds an LLM in Public International Law from the University of Amsterdam. Abbi has worked within a diverse range of law firms and NGOs, with significant experience advising on environmental corporate accountability in Europe and South America. She is a member of WYCJ’s Global Legal Taskforce.
***Joben Odulio-Camacho is a Filipino lawyer who obtained her LLM from the University of Pennsylvania, where she concentrated in Business and Human Rights. Joben’s work spans judicial decision writing, regulatory compliance, and international legal research. She is dedicated to promoting corporate accountability and sustainable development through the law.
