Abstract Scholarship and practice before the European Court of Justice indicate that international organizations can unilaterally bind themselves under international law. This article evaluates whether the International Maritime Organization did so with its 2018 'Strategy' to reduce greenhouse gas emissions from shipping. After first identifying the source of the imo's mandate to regulate greenhouse gas emissions from shipping and its treaty obligations to do so, it finds that the imo has the institutional competence to unilaterally bind itself with respect to its function and purpose of regulating vessel-source pollution. It further finds that the imo imposed on itself an erga omnes obligation to mitigate climate change in order to meet the Paris Agreement's global warming limitation goals. The article reflects on the implications of these findings for climate law and international law generally.