The research shows that 634 million people - one 10th of the global
population - live in coastal areas that lie within just 10 metres above sea level.
It calls for action to limit the effects of climate change, to help people migrate away from risk and to modify urban settlements to reduce their vulnerability. But it warns that this will require enforceable regulations and economic incentives, both of which depend on political will, funding and human capital. Key findings of the study by Gordon McGranahan of the International Institute for Environment and Development (UK) and his colleagues, Deborah Balk and Bridget Anderson, at the City University of New York and Columbia University, are that:
*Nearly two-thirds of urban settlements with more than 5 million inhabitants are at least partially in the 0-10 metre zone.
*On average, 14 percent of people in the least developed countries live in the zone (compared to 10 percent in OECD countries).
*21 percent of the urban populations of least developed nations are in the zone (11 percent in OECD countries).
*About 75 percent of people in the zone are in Asia.
*21 nations have more than half of their population in the zone (16 are small island states).
*Poor countries - and poor communities within them - are most at risk. "Urban development in the coastal zone brings multiple risks," says McGranahan. "It exposes people to seaward hazards such as storms, flooding and cyclones, and it can damage sensitive ecosystems including those such as mangrove forests that protect the coastline." "One in ten people, and one out of every eight urban dwellers, live on the coast no more than ten metres above sea level, but that number is increasing," says McGranahan.
"People are running towards risk, particularly in China but also in other parts of the world such as Bangladesh, where more than 40 percent of the land area is within 10 metres above sea level." China's economic boom has been driven by policies that promote coastal development and which have encouraged one of the largest coastward migrations ever. The study says that unless action is taken, China's economic success will be placed at risk.
