In a long-awaited decision, the Cantonal Court of Zug ("Court") on 17 December 2025 declared the climate lawsuit brought by four Indonesian islanders ("Plaintiffs") against Holcim AG ("Holcim") admissible. In essence, the Plaintiffs allege that their personality rights have been violated as a result of Holcim's excessive carbon dioxide ("CO₂") emissions. On that basis, the Plaintiffs seek a CO₂ emissions reduction order, as well as compensation for present and future damages.

Importantly, the Court will only decide on the merits of the case, if the decision is upheld. Holcim has already declared that it will appeal this decision.

Nevertheless, the decision already contains a series of arguments addressing the merits. This conundrum is explained by the so-called doctrine of double-relevance ("doppelrelevante Tatsachen"). Under this theory, a court establishes the procedural admissibility of the claim exclusively on the basis of the facts presented by the plaintiff. Provided that the plaintiff's arguments are presented conclusively and are not an abuse of rights, a court will assume that these facts are established even if disputed by the defendant and without taking any evidence. It will however do so only for the purpose of examining the admissibility of a claim. This is an important nuance. The Court did not state whether it agreed with the merits of the claims. Should the decision be upheld, the determination on the merits with proper evidence is reserved for the further course of the proceedings.

In assessing whether the procedural requirements for admissibility set out in art. 59 of the Swiss Civil Procedural Code are met, the Court had to examine whether it has jurisdiction over the case, whether the Plaintiffs have a legitimate and practical interest in bringing the claim (i.e., an interest worthy of protection), and whether the injunction sought is sufficiently concrete. Applying the doctrine of double-relevance, the Court had to examine a series of substantive arguments. Notably, these are key admissibility requirements that must be satisfied for a claim to be assessed by Swiss civil courts, and which courts around the globe have similarly grappled with in the context of climate litigation when determining whether the merits of such claims should be examined.

The Court's holding

The Court first had to decide whether it had jurisdiction over the dispute. In doing so the Court had to examine whether the dispute concerned a justiciable private-law matter or a public-law matter as civil courts cannot decide on public-law matters (c. 3.6-3.9). The Court considered that the claim concerned the protection and enforcement of the Plaintiffs' personality rights. Judicial decisions on such rights are private-law matters that complement climate policy. Moreover, the Court found that the political dimension of climate change would not preclude the application of private civil law.

As a further prerequisite for admissibility, the Court had to examine whether the Plaintiffs had a legitimate interest worthy of protection in bringing the action (c. 4-5). This requires, inter alia, that a plaintiff is personally affected by the defendant's actions, an issue that can be particularly challenging where conduct potentially affects large groups or even the global population. In addition, the action must be capable of actually improving the plaintiff's position. Here, the Court first found that the Plaintiffs are personally, specifically, and directly affected by the impacts of climate change, irrespective of whether others are affected as well. The Court further held that a private-law lawsuit could not be rejected on the basis that "everyone could sue everyone". Interestingly, the Court noted that a liability threshold for greenhouse gas emitters could be defined on the basis of quantitative criteria to restrict the group of potential defendants. Moreover, it held that individual measures must be regarded as practically useful and legitimate, given that a comprehensive solution to climate change may not be found in due time. Finally, the Court concluded that neither the "drop in the ocean" defense (i.e., that the emissions at issue are negligible on a global scale) nor the "market substitution" defense (i.e., that other market participants would emit in an emitter's place) precluded the existence of a legitimate and practical interest. According to the Court, every contribution to climate mitigation matters.

Lastly, the Court had to consider whether the prayers for relief are sufficiently concrete, as only such prayers can be enforced (c. 6). One issue was whether the reference to technical terms such as "Scope 1, 2 and 3 emissions" in the prayers for relief was sufficiently clear. The Court affirmed this. Furthermore, while the action was directed against Holcim, the requested relief includes an order against Holcim to amend its group-wide conduct through its board of directors. Here, the Court observed that the board of directors approves climate targets and bears responsibility for climate-related risks at group level. The Court further noted that a parent company may, under certain circumstances, be held liable as a factual corporate body of a subsidiary.

A significant development for Switzerland… but not a preview on the merits

Despite being limited to procedural considerations and assessed under the lens of unproven facts, this decision – if upheld – marks a significant development for corporate climate litigation in Switzerland. It indicates that, in principle, Swiss courts may examine tort-law climate claims against corporate entities responsible for CO₂ emissions. However, should the case make it to the merits stage, the Plaintiffs will face substantial legal and evidentiary challenges (e.g., basis for tort, causation). And the Court's admissibility reasoning should not be seen as a preview of the Court's position on the merits.

Practical consequences for Swiss companies

If upheld, the practical consequences for Swiss companies will be manifold:

• It may well mean that companies will increasingly become targets of ESG-related civil litigation in Switzerland;
• Notwithstanding the rejection of the Responsible Business Initiative ("Konzernverantwortungsinitiative") in 2020 and irrespective of the outcome of the pending Responsible Business Initiative 2.0, Swiss multinationals may find themselves as defendants before Swiss courts for the worldwide activities of their subsidiaries;
• The Court appeared to suggest that primarily the largest corporate emitters of CO₂ (the so-called "carbon majors") may be the target of ESG-related civil litigation in Switzerland. Should this be the case, the liability exposure for companies with comparatively low emissions could be limited. However, admissibility decisions in other jurisdictions indicate that not only the "carbon majors" may be targeted. It therefore remains doubtful that ESG-related civil litigation risks are confined to "carbon majors" alone;
• As of now, ESG-related litigation claims continue to be grounded primarily in traditional legal concepts (e.g. extra-contractual liability); however, evolving regulatory frameworks such as newly-introduced ESG regulations may add further weight to the claims;
• Robust corporate governance continues to remain the most effective defense, including properly mapping the global ESG-related litigation risk landscape and engaging as appropriate.