Stepping stone or stumbling block? Mode 2 knowledge production in sustainability science

• We examine the notion of Mode 2 science in the field of sustainability science.
• Our survey highlights several tensions in Mode 2, and between Mode 2 and sustainability science.
• The epistemic and cognitive implications of Mode 2 are uncertain.
• Mode 2 as a way of achieving progress is normatively problematic.
• How unified understandings of Mode 2 and sustainability science should be is in dispute.

The concept of Mode 2 has often been seen as especially applicable to fields addressing grand challenges, such as climate change. Being a relatively new field—interdisciplinary in its approach, and focused on addressing such issues—sustainability science would appear to be a case in point. The aim of this paper is twofold: 1) to explore the perceived relation between Mode 2 and sustainability science, and 2) to advance the discussion of Mode 2 from a philosophical perspective. To address these questions we focus on three characteristic features of Mode 2: the notion of a distinct, but evolving framework; boundary crossing; and a problem solving capacity “on the move”. We report the results of a survey carried out amongst leading sustainability scientists. The survey gives insight into the scientists' perception of Mode 2, their perception of their own field of sustainability science and the relation between the two. The free text answers reveal a tension within the field of sustainability science: with developments both towards Mode 1 and Mode 2 science. We conclude that the implementation of inter- and trans-disciplinarity is challenged by institutional and conceptual factors alike.