Zahar Koretsky is post-doctoral researcher in STS and transition studies at the French Research Institute for Agriculture, Food and the Environment (INRAE) and Gustave Eiffel University in Paris. He works on sustainability transitions, focusing on a critical take on it. His current research lies within sustainability transitions in the extractive sector. Zahar has published on the history of various declined technologies across the world and on the EU's climate change mitigation.

Peter Stegmaier is assistant professor at the Department of Technology, Policy and Society, section Science, Technology and Policy Studies (STePS) of the University of Twente, the Netherlands. Peter has worked as researcher and lecturer at the Universities of Dortmund, Hagen and Düsseldorf, carrying out at the latter two the project 'Law as a social practice-from everyday legal methods to a legal methodology for everyday work' (2000-2004); and as lecturer and researcher in criminal and police sociology at the Ruhr University of Bochum, focusing especially on public security institutions (2004-2006).

Bruno Turnheim is INRAE Research Scientist at the Interdisciplinary Laboratory on Sciences, Innovations and Societies (LISIS, Université Gustave Eiffel, France) and Honorary Research Fellow at the Manchester Institute of Innovation Research (MIoIR, University of Manchester, UK). His research focuses on socio-technical innovation and transition processes, particularly in relation to grand societal challenges.

Harro van Lente is full professor of Science and Technology Studies at the Faculty of Arts and Social Science, Maastricht University. He is one of the founding fathers of the Sociology of Expectations, which studies how representations of the future shape current socio-technical developments. He has published more than 100 journal articles, book chapters and edited volumes on technology dynamics, innovation policy and knowledge production. He is recipient of the 2018 EASST Freeman Award with the co-edited book (with Marianne Boenink and Ellen Moors), Emerging Technologies for Diagnosing Alzheimer's Disease: Innovating with Care.

1 Introduction: The relevance of technologies in decline; 2 Dynamics of technological decline as socio-material unravelling; 3 Destabilisation, decline and phase-out in transitions research; 4 Conceptual aspects of discontinuation governance: An exploration; 5 Discourses around decline: Comparing the debates on coal phase-out in the UK, Germany and Finland; 6 Mapping the territorial adaptation of technological trajectories: The phase-out of the internal combustion engine; 7 The role of alternative technologies in the enactment of (dis)continuities; 8 Caring for decline: The case of 16mm film artworks of Tacita Dean; 9 Implementing exnovation?: Exnovation ambitions and governance complexity in the case of the Brussels Low Emission Zone; 10 Phase-out as a policy approach to address sustainability challenges: A systematic review; 11 The end of the world's leaded petrol era: Reflections on the final four decades of a century-long campaign; 12 Conclusions and continuations: Horizons for studying technologies in decline