Climate Imagineering: Practices and politics of sunlight reflection and carbon removal assessment

This thesis explores recent proposals for novel carbon sinks (carbon removal) and planetary sunshades (sunlight reflection) – often treated as forms of climate engineering, or deliberate and large-scale climate interventions. I examine sunlight reflection and carbon removal as case studies of emerging sociotechnical strategies in climate governance, where imperfect projections produced by expert assessments influence political debate and planning. I explore the hidden politics of expert assessment: How knowledge is constructed, contested, and communicated by expert networks, and how these shape understandings of future climate options. My inquiries are grounded in analytical frameworks from the intersection of global environmental governance and science and technology studies, as well as stakeholder-facing technology governance frameworks such as ‘responsible research and innovation’. I ask three research questions. Firstly: How is knowledge and evidence about sunlight reflection and carbon removal created (Chapters 2 and 3)? I focus on scientific expert networks in the global North, and the aims, epistemologies, and effects of their assessment practices. Secondly: What does this knowledge do (Chapters 2, 3, 4, and 5)? I examine how assessment practices set in play resonant terms and frames of reference that actively – if imperfectly – steer climate governance in their image. Thirdly: How can this knowledge be used to bridge differences (Chapters 5 and 6)? I move from how knowledge is constructed to focusing on that construction as a form of experimentation – engaging with different expert networks and knowledge types to use assessment practices as platforms exploring new directions for research and policy. The chapters represent three directions. The first is from analytical to engagement work, using critical mappings of the knowledge economy to inform bridging activities amongst experts and stakeholders. The second is from retrospective to generative work – from analysis of how knowledge is constructed, to activities that use the future as a sandbox to generate new knowledge, and that in turn shape assessments. The final direction moves from general technological categories to specific approaches – engaging first with the wider politics of planetary interventions, and then with those of particular approaches and their expert networks. I begin with interpretive reviews. Tools of the Trade (Chapter 2) juxtaposes a mission-oriented mode of assessment prioritizing actionable evidence for policy audiences against a deliberative mode aiming for open-ended appraisal with diverse stakeholders. The Practice of Responsible Research and Innovation (Chapter 3) takes a more critical look at deliberative activities, pointing out that these, by setting themselves up against mission-oriented work, engage in the same implicit and instrumental politics of knowledge-making. Delaying Decarbonization (Chapter 4) examines the longer and wider arc of climate governance, treating sunlight reflection and carbon removal as sociotechnical strategies that draw on the same political rationales that have informed a host of antecedent strategies, from market mechanisms and carbon capture to shale gas and short-lived climate pollutants. I conclude with bridging and generative engagements on particular approaches. Is Bioenergy Carbon Capture and Storage Feasible? (Chapter 5) engages members of integrated assessment modeling groups and a multi-disciplinary group of critical experts, and finds that perspectives on how the ‘feasibility’ of novel climate options should be calculated are actually reflections on the influence of economic modeling work in climate policy. Engineering Imaginaries (Chapter 6) engages scholars invested in early conversations on the risk profiles and appropriate governance of a planetary form of sunlight reflection, and explores the value of anticipatory foresight approaches to create mutual learning amongst entrenched perspectives, and to generate governance that might be robust against many future plausibilities.