IGCP Project 639 Sea Level Change from Minutes to Millennia


Coastal areas are dynamic and fast changing environments. They are home to billions of people worldwide and provide areas of unique natural importance. Over millennia, changes in relative sea level, geological processes and extreme events such as storms and tsunamis have shaped and changed Earth’s coastlines. More recently, human activities such as coastal development and agriculture have affected coastlines through deposition and erosion, and through relative sea-level rise as a result of anthropogenic climate change. As such coastal change is of considerable local and global interest, not only within the geological realm, but also in terms of socioeconomic and biodiversity impacts.

Ten per cent of the global population (13 per cent of the world’s urban population) live less than 10m above sea level, with many more billions of people relying on the resources these regions provide, despite these areas only making up two per cent of global land¹. Increased public awareness of predicted future sea-level rise, combined with recent devastating extreme events has placed significant socioeconomic relevance on the understanding of coastal dynamics and the interactions between humans and coasts. The impending threat of sea-level rise to large low lying coastal cities such as New Orleans, Shanghai and Venice, countries with large areas of low-lying land such as Vietnam and Bangladesh and island communities such as the Maldives, Kiribati and Tuvalu have highlighted the importance of understanding relative sea-level change in the past to better predict the future. Similarly extreme events such as Hurricane Katrina, Cyclone Nargis, the 2004 Indian Ocean Tsunami and the 2011 Tohoku-Oki Tsunami have demonstrated the vulnerability of coastal communities the world over. As a consequence there is a growing realisation that an increasing number of people are vulnerable to coastal flooding associated with sea-level rise, storm surges, tsunami and river flooding.

The increased recognition of the vulnerability of coasts and coastal communities to changes (whether they occur over hours or millennia), presents the opportunity to learn from the past in order to reduce the risk to human life and infrastructure from future coastal changes. This project focuses on three research themes - catastrophic events, sea-level fingerprints and sea-level change – to identify records of past coastal change, aimed at understanding the impacts of human interactions, coastal dynamics and vulnerability at different timescales.

We aim to be able to use this information on past coastal change to provide an idea of what might be expected in the future, and thereby to inform policy and planning decisions. This information will be immediately relevant to a variety of stakeholders interested in the sustainability of coastal communities, such as emergency services (planning for extreme events), government agencies and insurers (resource management and strategies for mitigation and/or adaptation to sea-level change, flooding and the quantification of the recurrence interval of extreme events), and coastal engineers (e.g. planning defense against relative sea-level change).


McGranahan, G., D. Balk and B. Anderson. 2007. The rising tide: assessing the risks of climate change and human settlements in low elevation coastal zones. Environment & Urbanization 19(1): 17-37 (2007). International Institute for Environment and Development (IIED).



UNESCO is responsible for coordinating international cooperation in education, science, culture and communication.

organization website


International Union of Geological Sciences (IUGS) promotes and encourages the study of geological problems, especially those of world-wide significance, and supports and facilitates international and interdisciplinary cooperation in the earth sciences.

organization website


The International Geoscience Programme (IGCP) Better understanding the Earth is essential for the diversity of life and future of human society.

organization website


Sea-level changes over timescales from minutes to millennia are of great concern to coastal communities. Long-term changes in sea level due to the solid earths response to glaciation and tectonics are the background rate upon which the hazard from anthropogenic sea-level change and extreme inundation from tsunamis and storms must be superimposed. Short-term measurements from instrumental and historical records provide short glimpses at the hazard posed by sea-level change over varying temporal scales but must be placed within the long-term context that only geological and archaeological records provide.

This project will provide a platform for the development of integrated records of sea-level change and coastal hazards obtained from instrumental, historical, archaeological, and geological records. This project will place a particular focus on integrating disparate records in growth regions for science, namely in Africa, South America, and the Middle East, expanding upon previous coastal (495, 588) and delta projects (475) that focussed for the most part on Europe and Asia. Further, this project expands upon the research theme of project 588 that focused on the impacts of humans on coastal landscapes. This project will result in a coastal hazard toolkit that can be applied by those most at risk from future coastal inundation.