Climate Science in the Courts

This chapter explores the use of climate science in the courtroom. Expertise in the form of climate change science plays an indispensable role in governmental decision-making regarding the reduction of greenhouse gases. In order to make the (peer-reviewed) climate science accessible for policy-making, an important task is given to the Inter-Governmental Panel on Climate Change (IPCC). However, reports from the IPCC – together with other scientific documents - may also be used in the courtroom. This contribution explores what role IPCC reports have played thus far in seminal court decisions in the US and Europe. Furthermore, it observes that while the IPCC will stay important for decision-making in the context of the Paris Agreement, the IPCC and its decision-making procedures have not remained uncontested in legal (and other) literature. In tandem with the important role taken or given to the IPCC, fundamental legal questions regarding the production of climate science by the IPCC have to be examined, for which the concept of “global administrative law” may be useful since it examines the legitimacy and accountability of international decision-making. If courts are indeed willing to follow statements from the IPCC or from peer reviewed articles in such a way that this amounts to standard-setting, like a specific emission pathway, the rule-making power of the executive and legislative branch will clearly become less important and may be overturned. While this can be an enormous victory for climate protection, the implied shift of power still needs to be objectively identified and discussed, particularly also in view of helping to avoid unjustified contestation of climate science.