The 21st session of the Conference of the Parties (COP21) to the Barcelona Convention convenes this week to take stock of progress in achieving Good Environmental Status in the Mediterranean in the context of sustainable development. The meeting will not only provide the system with a clear mandate for a new Medium-Term (2022-2027) Strategy, but also push the boundaries on a number of crucial sustainability-oriented commitments that, if fulfilled, would bolster the region’s endeavor to achieve the 2030 Agenda. COP21 will address, at the highest levels, the issues of marine litter, marine protected areas (MPAs), climate change resilience and the blue economy.