AAP FACTCHECK – A prehistoric cave now submerged underwater is supposedly proof that humans aren’t contributing to rising sea levels, a Facebook post claims.
This is false. The entrance to the cave was covered by rising sea levels after the end of the last ice age thousands of years ago. Recent data shows humans are causing sea levels to increase via climate change.
The post appears in a Facebook group called “Australian Climate Sceptics Group”, which AAP FactCheck has checked previously.
“Does anyone else find it ironic that we are surrounded by irrefutable evidence that sea levels have been rising on this planet for Centuries, but suddenly it’s a man-made crisis?” the post states.
The post includes an article about the Cosquer Cave, an archaeological site near Marseille, France that has been submerged since its last human habitation around 20,000 years ago.
Experts told AAP FactCheck that while it’s correct that sea levels have been rising for millennia, there’s a distinct difference between the prehistoric rises that submerged the Cosquer Cave and the modern trends attributed to climate change.
Professor Ivan Haigh, an expert in ocean and earth science from the University of Southampton, said the post’s conclusion is “completely wrong”.
He said what caused the sea level rise resulting in the cave being submerged was the earth moving out of the last ice age, which peaked around 20,000 years ago.
However, Prof Haigh said the rate of change observed in the last 150 years “is very definitely driven by human induced climate change”, via melting of land-based ice due to warming temperatures.
“In recent years scientists have been able to… show very precisely what the drivers of the recent modern trends are and the majority of this can be traced to climate change,” Prof Haigh said.
Emeritus Professor John Church, from the University of New South Wales, told AAP FactCheck that the post implied “incorrect conclusions based on a lack of understanding”.
Prof Church explained that global sea levels rose rapidly by 120 metres after the end of the last ice age up to about 7,000 years ago.
He said sea levels then remained largely steady for thousands of years, only increasing around a few tenths of a millimetre each year on average.
However, sea level rise accelerated from the late 19th century following the Industrial Revolution.
Prof Church said that “global mean sea level rise is now an order of magnitude larger than the preindustrial values”, increasing about 4mm per year, and that rate is continuing to rise.
Ulster University’s Professor Andrew Cooper also refuted the post’s claim.
He said that modern observations with tide gauges and satellite data “record a long-term increase in sea level that is matched by rising levels of greenhouse gases in the atmosphere and these can be attributed to human activities”.
The Verdict
False – The claim is inaccurate.
AAP FactCheck is an accredited member of the International Fact-Checking Network. To keep up with our latest fact checks, follow us on Facebook, Twitter and Instagram.
All information, text and images included on the AAP Websites is for personal use only and may not be re-written, copied, re-sold or re-distributed, framed, linked, shared onto social media or otherwise used whether for compensation of any kind or not, unless you have the prior written permission of AAP. For more information, please refer to our standard terms and conditions.
