Kiribati's beaches are doomed, say both its president and sea-level experts. Credit: Punchstock

Rising sea levels caused by climate change will force the inhabitants of a group of Pacific coral islands to abandon their homes by the end of the century, their president has declared.

Anote Tong, president of the threatened islands in the Republic of Kiribati, has appealed to the international community to take responsibility for rehousing his compatriots.

The Republic of Kiribati is a collection of 32 atolls and one coral reef island, sitting just west of the International Date Line and astride the Equator. The highest land in the island chain is less than 2 metres above water — most of the land is much lower, and flat. As sea levels rise, Kiribati's 97,000 inhabitants are going to have to find somewhere else to live before 2100, Tong says.

Tong was speaking in New Zealand, host of the United Nations' World Environment Day. “We may already be at the point of no return,” he told an assembled press conference.

'Goodbye kiss'

Environment experts agree that the islands' fate is almost certainly sealed. “You can take it as read,” says Martin Parry, co-chair of Working Group II of the International Panel on Climate Change (IPCC). “If we don’t do anything, Kiribati can certainly kiss us goodbye.”

Half a metre of sea level rise is a heck of a lot for islands like that. Martin Parry , IPCC

Even if rises in world greenhouse-gas emissions were reversed, the delayed effect of climate on sea-level rises is such that it is already impossible to save the islands, says Parry. “There’s probably about 100 years' inertia in sea-level rises,” he says. “We have probably left it too late.”

The IPCC’s 2007 report predicted a 30–50-centimetre rise in global sea levels during this century. That figure was a conservative estimate, because potentially large contributions from Western Antarctica and Greenland were not considered owing to a lack of consensus on them at the time.

“Since then, a number of studies have identified that accelerated ice losses from these areas is occurring,” says Andy Shepherd, a contributing author of the 2007 report and head of the Earth Observation Research Group at Edinburgh University, UK.

Parry now calculates that limiting sea-level rise to 50 cm would require immediately cutting world greenhouse-gas emissions by half, and ultimately reducing them by 80% overall by 2050. But Kiribati is still doomed: “Half a metre of sea level rise is a heck of a lot for islands like that,” says Parry. Not only will flooding occur, but storm surges will increase, causing further devastation.

Prompting policies

Tong was in New Zealand to appeal to the prime minister to help rehouse the people of Kiribati, and Parry agrees that responsibility must be taken by the international community for these climate-change refugees. “This example shows we can’t really avoid some of these big impacts. We’re already committed to them.” That commitment means putting in place international policies, he says. Such policies don’t yet exist, and Parry suggests that it will take an obviously climate-related disaster in a large developed nation, such as a drought in the US Midwest, to prompt such international action.

Tong is resigned to the fate of his home, which he can see beginning to submerge. Already villages are being eroded and have to be relocated, he says.

“There’s nothing we can do,” says Parry. “These are the most exposed of people [to the impacts of climate change]. “I think populations sited less than 100 centimetres above current sea level would be wise to consider relocation over the coming century,” says Shepherd.