Some 115,000 years ago when humans first arrived, the Earth was going through a warm period. Early Homo sapiens’ space was more limited at this point, as sea levels were 20 to 30 feet (six to nine metres) higher. The climate was largely the same as it is today, but scientists have noticed that our sea levels are nowhere near as high as it was for the first humans.
This has led some to the fearful conclusion that excess water is locked up in the ice sheets of Antarctica, and if the Earth and its oceans continue to warm, then sea levels could quickly stack up.
Researchers reached the conclusion by analysing ancient plants in the northern hemisphere – specifically the Arctic Circle.
The plant fossils were located on Baffin Island, in northeastern Canada, and scientists determined that the last time they grew was 115,000 years ago when the ice was also not covering them then.
However, the conundrum was that if temperatures are as warm now as they were 115,000 years ago, where is the ice which accounts for the excess 20 feet in sea levels?
A group of researchers then determined that the ice has been locked up on the other side of the world, in the ice sheets of Antarctica.
More specifically, the West Antarctic Ice Sheet which is mainly submerged under water.
The sheet has already thinned by more than 700 metres near the coast throughout the past 10,000 years, and as oceans continue to warm, sea levels could rise astronomically in the future.
Rob DeConto, an Antarctic expert at the University of Massachusetts, told the Washington Post: “There’s no way to get tens of meters of sea level rise without getting tens of meters of sea level rise from Antarctica.
“What we pointed out was, if the kind of calving that we see in Greenland today were to start turning on in analogous settings in Antarctica, then Antarctica has way thicker ice, it’s a way bigger ice sheet, the consequences would be potentially really monumental for sea level rise.
“We cannot recreate six meters of sea level rise early in the Eemian without accounting for some brittle fracture in the ice sheet model.”
Mr Decanto and his colleague David Pollard, ran simulations which examined the melting of ice in the North Pole, and they warn that if the same process happens in the Antarctic, the consequences could be devastating.
Mr DeCanto said: “What we pointed out was, if the kind of calving that we see in Greenland today were to start turning on in analogous settings in Antarctica, then Antarctica has way thicker ice, it’s a way bigger ice sheet, the consequences would be potentially really monumental for sea level rise.”
According to Google’s interactive map, FireTree, a nine metre se level rise would make Britain and Ireland much narrower, while the likes of Holland will be almost completely submerged.