A Historic Verdict for Global Climate Justice: Higher Regional Court Hamm Rules on Liability of Major Emitters

On March 17 and 19, 2025, oral hearings took place before the Higher Regional Court (German: Oberlandesgericht, or OLG for short) Hamm in a historic legal case: Saúl Luciano Lliuya from Peru has been suing the energy giant RWE since 2015 for damages for its contribution to the climate crisis. Today, May 28, 2025, the OLG Hamm announced its verdict – marking an important step in the development of climate law.

Course of the oral hearing in March

Legal history was made with the oral hearings in the case of Saúl vs. RWE in March of this year, as never before had a court case concerning the liability of greenhouse gas emitters for climate-related damages progressed so far. The atmosphere during the oral hearings was accordingly tense. The plaintiff's side attended public events in Berlin, Hamburg, and Münster as part of a media campaign before and during the hearing days, i.e. an art exhibition on the course of the proceedings, a public screening of a documentary about the trial, and a panel discussion with participants from the plaintiff's side. Media and public interest was high, filling the courtroom during the oral hearings. Solidarity rallies for Saúl also took place outside the courthouse.

Public interest was even greater today for the pronouncement of the verdict, as one of the most important stages after almost ten years of litigation concluded – creating a historic precedent.

An international sensation

The proceedings were also closely followed internationally, as this is the first decision rendered on specific climate-related liability of companies. Numerous similar cases concerning the liability of major emitters are ongoing globally, for example, State of California v. BP or City & County of Honolulu v. Sunoco in the USA, both of which essentially revolve around financial responsibility for climate damages. Today's judgment will certainly influence these ongoing proceedings – and possibly inspire further lawsuits in this area.

The central question: Is the probability of climate damage high enough?

The trial’s key question was whether the dangers of climate-related damages in Huaraz, Peru, can be explicitly attributed to RWE as a major emitter, and whether the company has a duty of liability for adaptation measures. Similar cases have so far revolved around other issues: The much-noticed Dutch case Milieudefensie v. Shell, for example, is focusing on emission reduction obligations. Immediate liability and related attribution issues are not subject of these proceedings in the Netherlands.

Meanwhile, the verdict announced today in the case of Saúl vs. RWE addresses a central preliminary question concerning RWE's liability – namely, whether the probability of damage occurring is set high enough: It had to be determined whether the existing probability of climate-related damage is sufficient to generally oblige RWE to financial measures. For this purpose, the following evidentiary question from the court's order for indication and evidence from 2021 first had to be clarified:

"Is there – as a result of the significant increase in the expansion and water volume of Laguna Palcacocha – a seriously threatening impairment (disturbance) of the plaintiff's residential property located below the glacier lagoon in Huaraz due to a flood and/or mudslide?" (translation by the author)

The court-appointed experts, Prof. Dr. Ing. Rolf Katzenbach and Prof. Johannes Hübl, essentially concluded that the probability of Saúl's property being hit by a flood wave over the next 30 years is one per cent – and that the water level in the event of such a flood would be up to 20 centimetres. Furthermore, the discussion revolved around technical and scientific questions rather than legal ones, which presented the parties involved in the proceedings with challenges.

Experts appointed by the plaintiff's side criticised these conclusions: Among other things, they argued that the increasing temperature rises in the coming years and the risk of rockfalls were not sufficiently taken into account.

Subsequently, the date of the verdict was set for April 14, 2025; however, the plaintiff's side received information beforehand that could justify the bias of the expert Prof. Dr. Ing. Rolf Katzenbach. Accordingly, the plaintiff filed a motion for recusal with the court, which postponed the pronouncement of the verdict to today, May 28, 2025.

An important judgment with a forward-looking perspective

In its ruling, the court has now decided that greenhouse gas emitters such as RWE can principally be held liable under German civil law (section 1004 paragraph 1 sentence 2 BGB). It has thus taken an important step towards establishing the liability of major emitters. At the beginning of its reasoning, the court pointed out the absolutely special nature of the case, the importance of the legal issues at hand, as well as the global significance of the proceedings.

The mere fact that the court entered into the taking of evidence had left little doubt that a claim under section 1004 paragraph 1 sentence 2 BGB generally exists – the question was therefore whether the conditions were met in the present case.

However, this was rejected as, according to the court, there was not a sufficiently high probability that damage to Saúl's property would occur.

In the court's view, the circumstances presented by the experts were thus not sufficient to establish a high enough probability of damage occurring. This was a central prerequisite for establishing RWE's liability. The fact that this was not seen in the present case should not necessarily be regarded as a setback: Rather, the guide rails have now been laid for what needs to be considered in future climate lawsuits if climate liability of emitters is to be asserted in court.

Although the judgment has high political significance and is to be regarded as a precedent in every respect, the final word has not yet been spoken: It can be expected that further lawsuits against other emitters will follow, in which the prerequisites for climate-related liability issues will be discussed again and in other constellations. However, the possibility of an appeal on points of law (German: Revision) to the Federal Court of Justice, the highest instance of German civil jurisdiction (German: Bundesgerichtshof), was refused by the court in this case.

In essence, Saúl himself was not granted climate justice today. However, the ruling is likely to be extraordinarily relevant and widely received due to its impact.