This book has given me the great fortune to meet and work with a whole lot of wonderful people whose inspiration, support, and companionship I am deeply grateful for. These encounters and conversations each added further layers to this project, shaping it into what it is today.

This book started as a PhD thesis at the University of Bonn. I owe many thanks to my colleagues at the Forum Internationale Wissenschaft who have provided a wonderful environment for this research project to grow. I particularly want to thank my supervisors, Rudolf Stichweh and David Kaldewey, for granting me with the necessary trust, space, and resources. David Kaldewey and Daniela Russ continuously nourished my fascination with this project. Their questions, comments, and good sense have formed this work in many intangible ways. Our discussions in and out of the office sent me on a turbulent and somewhat odd journey through various strands of literature from systems theory, through science studies, and STS. David and Daniela read and commented on so many different bits and pieces, drafts and versions of this manuscript that I can only hope they like this final text and what I made of their invaluable commentary. The Stiftung Mercator has generously funded large parts of this research.

A set of expert interviews has provided valuable entry points and helped me to make sense of the wondrous world of climate engineering early on. I thank Jason Blackstock, Daniel Hayen, Joshua Horton, Hugh Hunt, Pete Irvine, Ben Kravitz, Jon Egil Kristjannson, Francesc Montserrat, David Morrow, Ted Parson, and Phil Renforth for their time and thoughtfulness. Our conversations brought some light into the dark and set me on track.

I was lucky enough that Jim Fleming agreed to participate in a small workshop which I hosted in Bonn during the early stages of this project. Since then, our exchanges have provided me with the necessary courage to embark on this historical-sociological journey. His scholarship and mentorship have pushed me down the rabbit hole of the ‘usable history’ of climate engineering. I thank him for paving the essential historical grounds for my sociological inquiry.

I had the pleasure to do much of the analysis and some of the writing of this book during a research stay in Boulder, Colorado. The Fulbright Commission provided a much-appreciated grant that made this field trip possible. Above all, I want to thank the scientists I had the pleasure of interviewing during my time in Boulder: Waleed Abdalati, John Barnes, Jim Butler, and Warren Washington. By taking the time and energy to attend to my questions and guiding me through your labs, you brought life to the oftentimes painfully dull policy documents, bills, and reports that I had been digging through for months. Max Boykoff and the entire team of the former Center for Science and Technology Policy Research at the University of Colorado, Boulder, have provided me with a wonderful research environment and good company. I especially want to thank Robin Moser, Brianne Eby, and Kevin Adams for making me feel home away from home.

A number of exchanges during the final stages of this project have helped me get this project through the finishing line. Kostis Chatziathanasiou has not only read and commented on every last bit of this text, but our conversations and his feedback have kept me going when it was the hardest. Ongoing conversations with Ina Möller have not only been of great pleasure but helped me tremendously in streamlining my argument and putting the finishing touches on my manuscript. Javier Lezaun has generously offered extensive feedback on several chapters of this manuscript. The attendees of two lunchtime seminars at Cambridge (UK) and Hamburg have provided their insights and critique on the final outline of this book.

I want to thank Mattering Press for doing a fantastic job. Two reviewers and especially my editor, Joe Deville, helped me turn a PhD thesis into a book that some people might actually want to read. Joe, our relentless back and forth is something I will never forget. Thank you for your time, energy, and thoughtfulness.

Finally, Kostis Chatziathanasiou, Daniela Russ, and Moritz Klenk have kept me afloat. Our conversations have been a source of life during the past months and years; you have ensured my happiness throughout all of it.