Climate change is having particularly devastating impacts on the world’s oceans: they are becoming warmer and more acidic, with profound consequences for their complex ecosystem. The special report on “The Ocean and Cryosphere in a Changing Climate”, due to be presented by the Intergovernmental Panel on Climate Change (IPCC) on 25 September, evaluates current scientific research on changes to the oceans. The Marine Regions Forum will convene in Berlin shortly afterwards with the aim of delivering clear recommendations, actionable results, and more support for regional partnerships.