Geoengineering technologies, such as solar radiation management (SRM), and negative emissions technologies, such as greenhouse gas removal (GGR), are emerging options to address climate change. This project will investigate the environmental, technical, social, legal, and policy dimensions of GGR and SRM. We provide an urgently needed interdisciplinary and holistic perspective of these technologies in order to understand conditions under which they might be deployed at scale. Our meta-analytical framework integrates insights from social science, engineering and physical science disciplines to provide a comprehensive view of GGR and SRM in the transition to climate neutrality in Europe and the world. The project will conduct excellent research and generate a robust, scientific assessment for evidence-based policymaking. Our research framework consists of three pillars—techno-economic systems, socio-technical systems, and systems of political action—within which we place six work packages (WPs). These are: (1) Understanding the current state and future potential of GGR and SRM technologies in terms of their technical and economic features; (2) Analysing bottlenecks in transitions to climate neutrality and their implications for deployment; (3) Identifying social acceptance and legitimacy constraints, (4) Learning, diffusion, and adoption; (5) Implications for Sustainable Development Goals of archetypical mitigation pathways; and 6) Policy options and governance. A crosscutting WP7 synthesizes research along three salient, but under-researched themes: A) Socio-technical change; B) Managing transition risks; and C) Political economy and feasibility of deployment. WP8 focuses on stakeholder engagement, entailing scenario co-design, science-policy dialogue formats, and specific outreach formats for target groups.