Global warming could create "ghost states" with governments in exile ruling over scattered citizens and land that has been abandoned to rising seas, an expert said yesterday.
Francois Gemenne, of the Institute for Sustainable Development and International Relations in Paris, said the likely loss of small island states such as Tuvalu and the Maldives raised profound questions over nationality and territory.
"What would happen if a state was to physically disappear but people want to keep their nationalities? It could continue as a virtual state even though it is a rock under the ocean and its people no longer live on that piece of land."
Gemenne said there was more at stake than cultural and sentimental attachments to swamped countries. Tuvalu makes millions of pounds each year from the sale of its assigned internet suffix .tv to television companies. As a nation state, the Polynesian island also has a vote on the international stage through the UN.
"As independent nations they receive certain rights and privileges that they will not want to lose. Instead they could become like ghost states," he said. "This is a pressing issue for small island states, but in the case of physical disappearance there is a void in international law."
Experts say it is a matter of time before global warming drives up sea levels the one or two metres it would take to force permanent evacuation of islands such as Tuvalu, the highest point of which is four metres above water.
The study of 23 regions where environmental degradation has caused people to move had showed that fears of millions of people flooding across borders could be misplaced. Most movement was within countries, Gemenne said.
The poorest and most vulnerable people were often unable to migrate, the research showed. "The poorest people lack the social and economic capital to escape," said Gemmene.
Simon Hales of the World Health Organisation told the conference that widespread population movement would also pose a significant risk to global health. Health protection in a 4C warmer world, he said, would require "substantial redistribution" of global resources such as food, water and energy.