In many climate change
litigation cases, courts are asked to consider scientific evidence, such as the
International Panel on Climate Change (IPCC) reports. The European Court of
Human Rights (ECtHR) in their decision Klimaseniorinnen v. Switzerland may have
misunderstood some aspects in those reports. The International Court of
Justice’s (ICJ’s) advisory opinion on the obligations of states regarding
climate change was written after the judges had consulted members of the IPCC
on the science; possibly, that helped them to a better understanding. This
article examines how the ECtHR understood the IPCC reports on the matter of
national carbon budgets and discusses whether a court expert could have helped
them. While such an expert consultation may have contributed to the ICJ’s
understanding, it concludes that the mere presence of a court expert would not
guarantee a perfect understanding on the side of the court. Instead of
mandatory experts, it suggests, courts should themselves be allowed recourse to
experts, where they – honestly – consider fit.