GLOBAL warming could be returning the world to the way it was four million years ago when sea levels were 80ft higher than they are today, scientists say.
The forecast suggests that a climatic “switch” may soon be thrown, resulting in a seismic geothermal shift.
If the prediction is correct, later generations could find themselves living in a climate similar to that of the early Pliocene epoch.
Even though at that time the greenhouse effect of atmospheric carbon dioxide was no greater than it is today, average global temperatures were at least 3C warmer.
Sea levels were 25 metres, or 82ft, higher four million years ago during the early Pliocene. Such a rise would have a devastating effect on human populations around the world, submerging whole islands and coastal cities.
The epoch was also marked by droughts and torrential rains.
Human evolution may have depended on the onset of drier conditions about three million years ago, when ice started spreading in the north and the Earth began to cool. Experts writing in the journal Science say human-induced climate change may already be pushing the “switch”.