Abstract
Using techniques commonly applied in participatory action research and ethnography, we examine 20 specific cases of experimentation for a selection of carbon removal and solar radiation modification interventions. These experiments include engineering-based approaches such as stratospheric aerosol injection, cloud brightening, carbon–neutral cement, biochar, direct air capture, and enhanced rock weathering alongside ecosystems-based approaches such as afforestation, seagrass restoration, and coral reef protection. Based on extensive original research of these 20 experimental projects—including 118 semi-structured research interviews and naturalistic site-based observation—we explore four questions. Firstly, what are the actor coalitions surrounding each experiment? Secondly, what promises and expectations do those actors generate? Thirdly, what innovation dynamics and styles are emergent and evident here? Finally, what perceived co-impacts are expected (by actors) to occur with widespread prospective deployment? Answering these questions in our empirical study offers insights into energy, climate, and climate intervention research, given that these experiments involve some of the most powerful and dominant actor coalitions, are supported by large amounts of climate finance investment, and will undoubtedly shape future deliberations over climate policy and technology deployment.