The ocean is the largest active carbon pool on Earth, acting as the key regulator to global climate change, and thus has great potential for carbon negative emission. The Global Ocean Negative Carbon Emissions (Global-ONCE) program has been approved by the Intergovernmental Oceanographic Commission (IOC) of the United Nations Educational Scientific and Cultural Organization (UNESCO) in the framework of the United Nations’ call for Decade Actions of Ocean Science for Sustainable Development and the United Nations Decade Initiative Plan. Global-ONCE UN decade program will last for 10 years starting from 2022. Global ONCE is joined by 78 partner organizations from 33 countries, including the North Pacific Marine Science Organization (PICES), the International Council for the Exploration of the Sea (ICES), the Integrated Marine Biosphere Research (IMBeR), Ocean-based negative emission technologies (Ocean NETS), etc. The objectives of Global ONCE are to provide the data, knowledge, opportunities and practices to enable society to evaluate mitigation approaches to climate change. These include the establishment of a network of instrumented marine monitoring stations and research facilities to evaluate ONCE approaches such as integrated land-ocean managements, seaweed cultivations, ocean alkalinity enhancement, nutrient fertilization, artificial upwelling and recovery of marine ecosystems; formulation of decision rules for initiation and evaluation of these approaches; facilitation of co-designed interdisciplinary collaborative research on key carbon sequestration processes; development of technical and personnel capacity and enhancement of knowledge exchange between scientists, policymakers, industries and societies; implementation through careful co-design and development of ONCE technologies, development of ONCE protocols and standards for carbon sequestration in the ocean; co-producing best practice manuals, professional and science-popularization training, and providing evidence-based advice to the IPCC and COP meetings of the UN Framework Convention on Climate Change.

Global ONCE is supported by the Intergovernmental Oceanographic Commission (IOC), the United Nations Educational Scientific and Cultural Organization (UNESCO), the United Nations’ Ocean Decade Actions; the Ministry of Science and Technology (MOST) and National Natural Science Foundation of China (NSFC).