Summary

Coastal cities are increasingly vulnerable to tsunamis and rising sea levels, posing significant risks to lives, infrastructure, and economies. As urban populations along coastlines continue to grow, strengthening early warning systems, enhancing resilient infrastructure, and improving community preparedness are essential to reducing the devastating impacts of these unpredictable hazards.

Tsunamis are among the most destructive oceanic threats, capable of striking within minutes or hours—often without warning—and impacting entire ocean basins and even multiple regions. Meanwhile, sea level rise, driven by climate change and land subsidence, intensifies coastal flooding, accelerates shoreline erosion, and contaminates freshwater resources. These challenges not only endanger communities but also disrupt vital infrastructure such as ports, harbors, and maritime transport networks.

Following the catastrophic Indian Ocean Tsunami on December 26, 2004, UNESCO’s Intergovernmental Oceanographic Commission (IOC-UNESCO) was mandated by the United Nations to establish global tsunami warning systems across different ocean basins. This led to the creation of four regional warning and mitigation systems: the Pacific Tsunami Warning and Mitigation System (PTWS), the Indian Ocean Tsunami Warning and Mitigation System (IOTWMS), the North-eastern Atlantic, Mediterranean and Connected Seas Tsunami Warning System (NEAMTWS), and the Caribbean and Adjacent Regions Early Warning System (CARIBE-EWS), each overseen by an Intergovernmental Coordination Group (ICG).

In June 2021, IOC-UNESCO launched the Ocean Decade Tsunami Programme (ODTP) as part of the UN Decade of Ocean Science for Sustainable Development. This initiative aims to enhance global tsunami warning systems by reducing response times, improving warning accuracy, and enhancing community resilience through programs such as UNESCO-IOC Tsunami Ready. The ODTP aligns with the Sustainable Development Goals (SDGs) and the Sendai Framework for Disaster Risk Reduction (SFDRR) while complementing broader initiatives like UN Early Warnings for All (UNEW4All).

Through a series of expert talks and interactive discussions, this session will:

1. examine the challenges coastal cities face due to tsunamis and other ocean-related hazards, including sea level rise,
2. showcase advancements in tsunami early warning systems and community preparedness, and
3. explore opportunities for integrating tsunami warning systems into broader multi-hazard early warning frameworks,
4. build partnerships with the “Cities with the Ocean” platform for enhancing community resilience to ocean hazards through programs such as UNESCO-IOC Tsunami Ready.