The ice sheet melting at the end of the last ice age may have raised sea levels by ten times the current rate, a study published Thursday by a team led by scientists from Durham University in Britain.
Based on geological reports, researchers estimate that oceans worldwide have risen about 3.6 meters per century over a period of 500 years about 14,600 years ago.
The findings raise a red flag about the potential for rapid sea level rise that could overwhelm coastal cities and densely populated deltas around the world.
The team found that the rising event of about 18 meters at sea level was mainly due to the melting ice sheets in the northern hemisphere and not from Antarctica as previously thought.
According to the scientists, their work could provide ‘important clues’ about the future melting of ice sheets and sea level rises due to climate change.
“We found that the largest rapid rise in sea level was due to the melting of ice sheets in North America and Scandinavia, with a surprisingly small contribution from Antarctica,” said study co-author Pippa Whitehouse of the Department of Geography. Durham University said.
“The next big question is to find out what caused the ice melt, and what impact the massive influx of meltwater had on ocean currents in the North Atlantic.
“This is very much on our minds today – any disruption of the Gulf Stream, for example due to the melting of the Greenland ice sheet, will have significant consequences for the British climate.”
Current models used by many climate scientists estimate that world sea levels could rise by between 1 and 2 meters by the end of this century.
The Durham researchers used detailed geological sea level data and modern modeling techniques to uncover the sources of the dramatic five-century rising event at sea level.
Compared to the melting of an ice sheet twice as large as Greenland, it led to the flooding of vast areas of low-lying land and interrupted the circulation of the ocean, with consequences for the world climate.
“Our study contains new information from lakes around the coast of Scotland that have been isolated from the ocean due to the uplift of the country following the withdrawal of the British ice sheet, which enables us to identify the meltwater sources with confidence,” he said. co-author Yucheng Lin, also added. of Durham’s Department of Geography.
Identifying the source of the meltwater will help improve the accuracy of climate models used to replicate the past and predict changes in the future, the team added.
They noted that the findings were particularly timely as the Greenland ice sheet melted rapidly and contributed to a rise in sea level and changes to global ocean circulation.
In 2019, Greenland dumped more than half a billion tonnes of ice and meltwater, accounting for 40 percent of the total sea level rise that year.
© Agence France-Press