Tsunamis are an ever-present threat to lives and property along the coasts of most of the world’s oceans. As the Sumatra tsunami of 26 December 2004 reminded the world, we must be more proactive in developing ways to reduce their impact on our global society.This article provides an overview of the state of knowledge of tsunamis, presents some
challenges confronting advances in the field and identifies some promising frontiers leading to a global warning system. This overview is then used to develop guidelines for advancing the science of forecasting, hazard mitigation programmes and the development of public policy to realize a global system. Much of the information on mitigation and forecasting draws upon the development and accomplishments of a joint state/federal partnership that was forged to reduce tsunami hazards along US
coastlines—the National Tsunami Hazard Mitigation Programme. By integrating hazard
assessment, warning guidance and mitigation activities, the programme has created a
roadmap and a set of tools to make communities more resilient to local and distant
tsunamis. Among the tools are forecasting, educational programmes, early warning
systems and design guidance for tsunami-resilient communities. Information on
international cooperation is drawn from the Global Earth Observing System of Systems
(GEOSS). GEOSS provides an international framework to assure international
compatibility and interoperability for rapid exchange of data and information.