'Two billion refugees as oceans rise'
An estimated two billion people could become climate change refugees by the end of the century because of rising sea levels, experts have warned.
Coastal populations will create resettlement bottlenecks as they flee in search of new places to live inland, say researchers.
At the same time, swelling oceans will add to world food shortages by consuming farmland in fertile coastal plains and river deltas, it is claimed.
By 2060, about 1.4 billion people could be displaced by rising sea levels, with the number rising to two billion by 2100.
Lead scientist Professor Charles Geisler, from Cornell University in New York, said: "We're going to have more people on less land and sooner than we think. The future rise in sea level probably won't be gradual.
"The colliding forces of human fertility, submerging coastal zones, residential retreat and impediments to inland resettlement is a huge problem."
In their study, scientists explored a "worst-case scenario" combining the effects of sea level rises and a world population expected to reach 11 billion by 2100.