Rising sea levels threaten islanders with displacement

Flooding due to sea level rises could lead to the displacement of millions of people in South-East Asia and the Pacific, says the report

Flickr/IFRC

[MANILA] A significant rise in sea levels due to global warming could result in the loss of species and habitats in the coastal areas of more than a thousand islands in South-East Asia and the Pacific region, leading to the potential displacement of many millions of people, according to a study.

"Sea level rise will lead to the permanent inundation and erosion of coastal areas," said Florian Wetzel, first author of the study which appeared in the journal Global Change Biology, and an ecologist from the Konrad Lorenz Institute of Ethology of the University of Veterinary Medicine in Vienna, Austria.

Some of the areas at risk — such as Indonesia, Malaysia, the Philippines, East Timor, Papua New Guinea and Thailand — are known biodiversity hotspots. Others, like Fiji, Samoa and Vanuatu, possess endemic species.

The study, 'Future climate change driven sea-level rise: secondary consequences from human displacement for island biodiversity', points out that some species, particularly those mammals that range widely within low-lying coastal zones or in hinterland regions, could be wiped out entirely.

Many of these species, including endemic tigers, panthers, squirrels, rats, cats and monkeys, are already endangered.

People are also likely to have to migrate from coastal areas to island interiors due to permanent flooding in littoral settlements, added Wetzel.

The research modeled scenarios of sea level rises of one, three and six metres, and evaluated species vulnerability to the secondary effects of these rises, using published assumptions of sea level rise in the Pacific.

Depending upon the scenario, between 3 and 32 per cent of an area's coastal zone could be lost due to flooding — the primary effect of sea level rise. This would turn from 8 to 52 million people into flood refugees, said Wetzel.

Biologist Marilou Nicolas, executive director of the Center for Integrative and Development Studies at the University of the Philippines, confirms that "island nations are the most vulnerable to sea level rise."

"With the rise in sea level, it is expected that areas lower than 10 metres above sea level will be inundated," destroying beaches and marshlands, which are breeding grounds for animals such as turtles, Nicolas explained.

"The loss of a species can have a 'domino effect' on the survival of other species, because all living organisms are effectively connected in a web of life," she added.

Marine geologist Fernando Siringan, a member of the Philippines National Academy of Science and Technology, emphasised that the problem of sea level rise can also be traced to other factors, such as ground subsidence due to the movement of the Earth's tectonic plates, the transformation of mangrove areas into fishponds, or excessive groundwater withdrawal.

Link to the full study (subscription necessary)