Summary/Abstract
Plans to address climate change increasingly include proposals for geoengineering projects, whose effects are likely to be global, at best only partly predictable, not necessarily wholly benign, and extend beyond their objective. Geoengineering proposals should receive detailed, precautionary scrutiny by the international community, which requires sophisticated international legal instruments and implementation systems. Most advanced are proposals for climate related geoengineering projects that involve or affect the ocean, requiring assessment of their compatibility with international law of the sea. This paper summarizes these proposals, reviews the applicable legally binding global instruments and their mechanisms to assess and regulate geoengineering, and examines their implications for geoengineering in responding to climate change.It concludes that geoengineering projects must satisfy a suite of mandatory international legal requirements that are dedicated to protect and preserve the marine environment, or they cannot legally proceed.