Under the heading "Fragile Evidence", this issue focuses on the problem of decision making under uncertainty. The problem itself is not new: Modern societies have always owed their development dynamics to the transformation of uncertainty into partial certainty. However, the unrecognized could be relied on to be in principle recognizable. This certainty of rationality has not disappeared, but it has changed in form, says the editor of the thematic focus Stefan Böschen. Today, most contemporaries acknowledge the authority of science. However, the self-evident character of the allocation of this authority has vanished. Authority of knowledge is increasingly dependent on special epistemic procedures and institutional legitimation measures. Evidences become fragile.
The contributions to the thematic focus discuss evidence-based policy between non-ambiguity and reflexivity (Sabine Weiland) and systematically address the question of whether a switch to evidence and indicators can be observed in selected fields of risk policy in support of the precautionary principle (Arnim von Gleich, Christian Pade and Henning Wigger). In the implementation of the precautionary principle at EU level, chemicals policy plays a prominent role. Martin Scheringer therefore uses the example of the current chemicals policy to explore the scope and effectiveness of measures based on the precautionary principle. Silke Beck in her contribution focuses on the IPCC and discusses the ambivalent role that such an institution can play. Finally, Sebastian Cacean and Christian Voigt show how evidences can be visualized and analyzed using argument cards.
Special reference should be made to the article by Gerhard Schmidt, Gerald Kirchner and Christoph Pistner in the discussion forum, which addresses the problem of final disposal and asks: "Can partitioning and transmutation help?" As usual, this issue also presents TA projects (radioactive waste materials, eSecurity) as well as reviews of relevant conferences and publications in the field of TA.