Short abstract:

Climate litigation is on the rise worldwide. Whereas scientific expertise plays a crucial role in climate court cases, it remains scarcely researched. We empirically investigate a Dutch climate court case which heavily drew on IPCC model projections and reflect on the political position of the IPCC.

Long abstract:

Driven by the lack of climate action, climate activists are growing ever more litigious. As of December 2022, there have been a total of 2,180 climate court cases in 65 jurisdictions (United Nations Environment Programme, 2023). While the impact and import climate litigation has been studied extensively by legal scholars, it is a relatively new topic for political scientists, sociologists and science and technology studies (Setzer & Vanhala, 2019). This is a surprising gap, as scientific climate expertise plays a critical role in these cases. Whether determining if litigants have standing to sue or the attribution of climate impacts to the defendants’ actions, scientific expertise is crucial (McCormick et al., 2017; Setzer & Vanhala, 2019). In practice, the use of scientific expertise in climate cases varies greatly. For example, it remains unknown how scientific expertise influences court decisions, what forms of expertise are used, or how judges engage with this expertise. In this paper, we investigate the use of scientific climate expertise in the case of Miliedefensie v. Royal Dutch Shell and its ongoing appeal. In this case, the verdict – that the oil company would need to reduce CO2 emissions with 45% by 2030 – relied on heavily on IPCC model projections . Our paper empirically analyses how litigants mobilised IPCC scenarios by litigants and the larger role of these scenarios in the final verdict, providing insights into climate litigation’s politics of expertise. Finally, we reflect on climate litigation’s broader implications for the political position of the IPCC.