World's deltas face severe threats, warns IGBP chair James Syvitski

The authors call on the United Nations to "establish an international body of experts to coordinate delta-maintenance initiatives worldwide."

They urge governments to "accelerate scientific research and expand monitoring and forecasting programmes, impact studies and public consultations."

In the commentary, Climate Change: protect the world's deltas (Nature 4 December), they list five priority areas:

1. Plugging knowledge gaps is the most urgent task. "Observations should take advantage of new techniques and sensors. Satellite-based estimates of fluvial discharge or land subsidence are advancing. But more hydrological stations, tidal gauges and subsidence measurements are badly needed."

2. "Biophysical and biogeochemical research on wetland processes must be expanded to address the wide range of deltaic conditions. Agricultural and industrial practices need to be assessed to select sustainable practices."

3. Create "standardized methodologies developed under the advice of UN experts" and adopted by all affected areas. "Knowledge and data sharing on a common platform is crucial."

4. "A science-based global strategy for protecting deltas needs to be developed to reduce costs and risks." Including the need for a new "UN body of experts" to coordinate existing international and national initiatives.

5. Finally, the authors say the time to act is now to save money later: "River deltas need maintenance now rather than costly restoration later to prevent the collapse of vast expanses of coastline."

Further reading

Interview with James Syvitski (IGBP's Global Change magazine)

Deltas at Risk Infographic (IGBP's Global Change magazine)

Authors:

Liviu Giosan is an associate scientist in geology and geophysics at the Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA.

James Syvitski is professor of geological sciences at the University of Colorado, Boulder, USA, and chair of the International Geosphere-Biosphere Programme.

Stefan Constantinescu is a lecturer in geography at the University of Bucharest, Romania.

John Day is emeritus professor of ecology and coastal sciences at Louisiana State University, Baton Rouge, Louisiana, USA.