Summary/Abstract
Despite earlier calls for a pause, investment in geoengineering technologies and field experiments proposing to counter climate change is booming. At present there is no effective global governance regime to ensure that such technologies are safe, effective or equitable. This article explores the relevant obligations for geoengineering activities with potential impacts on the marine environment and explores what ‘due diligence’ for environmental impact assessments and strategic environmental impact assessments entails, considering, amongst other sources, the recent International Tribunal for the Law of the Sea Climate Change Advisory Opinion. It concludes that international rules and national regulations should build upon these obligations before any deployment is approved.