The UN International Decade of Ocean Science for Sustainable Development (2021-2030) will mobilize the global scientific community to encourage partnerships for joint research and technological innovation. This Decade consolidates UN efforts to boost international cooperation in marine science, providing more timely and reliable environmental predictions and information, days to months in advance. This Town Hall will address critical opportunities for joint World Meteorological Organization’s and Intergovernmental Oceanographic Commission’s decadal planning of ocean science, observations including Ocean Obs 19, and services for sustainable development. The program will address an integrated approach to earth system science (ocean/atmospheric) and observations to advance multi hazard early warning systems, improve early warning of ENSO impacts, support a continuous research-to-operations-to services value chain for earth system forecasting, and encourage data management and accessibility in order to help achieve the ocean decade and sustainable development goals including Sustainable Development Goal 14 on Oceans.