Receding Glaciers, Advancing Law: The Imperative of Using Best Available Science in the Case of Lliuya v. RWE and Beyond

Abstract

On 28 May 2025, the Higher Court of Appeal in Hamm (Germany) delivered a pioneering judgment in the case Lliuya v. RWE . The Court confirmed that German private nuisance law was applicable in the transnational context, and that the greenhouse gas emissions of the energy company RWE contributed to climate change and its adverse impacts. Based on the evidence provided, the Court concluded that the normative threshold of ‘imminence’ of a future, first-time property impairment was not reached. This article assesses the Court’s reasoning and the challenges it faced in determining ‘imminence’, considering conflicting scientific evidence. Against the backdrop of a legal and scientific analysis, the article argues that the physical laws underpinning climate change, and the scientific assessments of the Intergovernmental Panel on Climate Change, form a baseline of ‘best available science’ for the legal assessment of climate risks. Case-specific evidence that deviates from this baseline requires careful consideration. Furthermore, the legal interpretation of causally relevant evidence must depend on whether the science provides a qualitative or a quantitative statement.