Science-based monitoring, forecasting and early warning systems are powerful tools to meet the challenges that melting glaciers pose to water security, ecosystems, and the life and livelihoods of millions. But we must act together. Watch WMO Secretary-General Celeste Saulo’s message to mark the closing of the International Year of Glacier Preservation #Glaciers2025, and looking ahead to #WorldGlacierDay and #WorldWaterDay.