As sea-ice around Antarctica’s coastlines retracts, a massive ‘blue carbon’ area is emerging to replace it. This is a growing resource that is predicted to become the world’s largest natural carbon sequestration area. Given the loss of carbon sinks elsewhere and the existential threat of unabated climate change, this is an incredibly important global good that must be protected and promoted. In this chapter, we explore the legal and diplomatic barriers to that protection and posit potential solutions. In particular, we suggest vertical institutional linkage between the Antarctic Treaty System and the United Nations climate regimes as a way of incentivizing the establishment of global cooperative marine protected areas around Antarctica’s coasts.