Geoengineering the oceans: an emerging frontier in international climate change governance

International climate change policy is increasingly reliant upon future large-scale removal and sequestration of greenhouse gases from the atmosphere. Assumptions on the development of ‘negative emissions’ technologies are built into recent IPCC emissions modelling and the 2015 Paris Agreement. Terrestrial proposals, such as bioenergy with carbon capture and storage, may be of limited benefit as the estimated land required would be vast and may negatively impact upon food security. The world’s oceans could play an important role in meeting international climate change targets. ‘Marine geoengineering’ is being proposed to enhance the oceans capacity to sequester emissions and enhance the Earth’s albedo. This article draws on discussions at a recent Marine Geoengineering Symposium held at the University of Tasmania to highlight prominent marine geoengineering proposals and raise questions about the readiness of the international law system to govern further research and implementation of these ideas.