Ice sheet melting on the finish of the final ice age might have triggered sea ranges to rise at 10 instances the present fee, a examine revealed Thursday by a workforce led by scientists from Britain’s Durham University mentioned. Based on geological data, the researchers estimate that oceans worldwide rose 3.6 metres per century over a 500-year interval some 14,600 years in the past.
The findings increase a crimson flag in regards to the potential as we speak for speedy sea degree rise that might swamp coastal cities and densely populated deltas all over the world.
(*10*)The workforce discovered that the roughly 18-metre sea degree rising occasion might have originated primarily from melting ice sheets within the northern hemisphere and never Antarctica as beforehand thought. The scientists say their work might supply “vital clues” about future ice sheet melting and sea degree rises due to local weather change.
“We found that most of the rapid sea-level rise was due to ice sheet melt across North America and Scandinavia, with a surprisingly small contribution from Antarctica,” mentioned the examine’s co-author Pippa Whitehouse, of Durham University’s geography division.
“The next big question is to work out what triggered 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 to the Gulf Stream, for example due to melting of the Greenland Ice Sheet, will have significant consequences for the UK climate.”
Current fashions utilized by many local weather scientists estimate world sea ranges might rise by between 1 and a couple of metres by the top of this century. The Durham researchers used detailed geological sea-level information and state-of-the-art modelling strategies to reveal the sources of the dramatic five-century sea degree rising occasion.
Comparable to melting an ice sheet twice the scale of Greenland, it resulted within the flooding of huge areas of low-lying land and disrupted ocean circulation, with knock-on results for world local weather, they mentioned.
“Our study includes novel information from lakes around the coast of Scotland that were isolated from the ocean due to land uplift following the retreat of the British Ice Sheet, allowing us to confidently identify the meltwater sources,” added co-author Yucheng Lin, additionally of Durham’s geography division.
Identifying the supply of the meltwater will assist enhance the accuracy of local weather fashions which can be used to replicate the previous and predict modifications sooner or later, the workforce added.
They famous the findings had been notably well timed with the Greenland ice sheet quickly melting and contributing to an increase in sea ranges and modifications to world ocean circulation. In 2019, Greenland solid off extra than half-a-trillion tonnes of ice and meltwater, accounting for 40 p.c of complete sea degree rise that 12 months.
