According to the latest IPCC reports, the world will likely need carbon dioxide removal (CDR) to limit the warming of the planet to 1.5 °C by the end of the century. Marine CDR (mCDR) technologies have therefore emerged as a potential solution to mitigate climate change. While mCDR can be deployed unilaterally, its maximum efficiency requires international coordination due to potentially extensive transboundary effects. However, the current international legal framework, including the UNFCCC and the Paris Agreement lack a dedicated regime for mCDR, resulting in the application of ill-suited regulations. In this context, principles of international law, which could provide guidance on the permissibility of mCDR, instead add to the confusion. This chapter addresses the unrealistic expectation of current legal frameworks to overly rely on unequivocal instructions from natural sciences to eliminate the risks, and provides two avenues to contend with risks. One comes to encouraging the use of best science through transparency and standardisation. The other circumvents risks by restraining overuse of mCDR while improving liability mechanisms. Contrary to the prevailing notion of the law’s impotency in the face of scientific uncertainty, it seeks to oppose this scepticism by offering legal remedies that, if not eliminating the risk entirely, aim to mitigate and frame it effectively.