Novel marine-climate interventions hampered by low consensus and governance preparedness

Novel marine-climate interventions are now being rapidly implemented to address both the causes and consequences of warming oceans. However, the governance implications of proposed upscaling of such interventions are uncertain. We conduct a survey of 332 intervention practitioners, revealing five types and 17 sub-types of interventions proposed or deployed in 37 marine systems globally. Most (71%) report marine-climate interventions aimed at supporting species and ecosystem adaptation, with 29% aimed primarily at climate mitigation and societal adaptation. Perceptions of climate benefits vary widely, with low consensus across practitioners on the climate goals of specific interventions. Intervention decision-making also remains focused on technical feasibility to meet minimum permitting requirements, with limited appraisal and management of broader ecological, cultural and social risks and benefits of intervention. Practitioners also warn that many marine-climate interventions are currently being tested and deployed in an under-regulated pseudo-scientific bubble. Oceans are on the front line of new planned climate actions, but understanding of novel marine-climate intervention development and deployment remains low. Here a survey among intervention practitioners allows identification of science and governance gaps for marine-climate interventions.