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An enormous ice sheet is at risk of melting even if temperatures rise by just 2°C, potentially sparking major climate chaos.
Scientists say that if the East Antarctic Ice Sheet –which is 60 times the size of England – melts, sea levels could rise by four meters, putting areas of the UK at risk of disappearing entirely.
Experts are now warning that more needs to be done to prevent continued global warming.
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Melting ice can have a devastating effect on the world, causing the planet to heat up more quickly, changing ocean circulation systems that regulate global weather, and increasing the risk of flooding and tsunamis damage.
A study into historical ice loss suggests even “moderate warming” of Earth could melt the East Antarctic Ice Sheet.
“With current global temperatures already one degree higher than during pre-industrial times, future ice loss seems inevitable if we fail to reduce carbon emissions,” said Dr. David Wilson, of Imperial College London, who worked on the research.
Scientists have poured lots of effort into investigating the West Antarctic Ice Sheet, which mostly sits on land below sea level.
Due to its low-lying position, it contributes to most of the continent’s ice melt today.
But experts at Imperial College London and the University of Queensland have now investigated risks facing the East Antarctic Ice Sheet.
The EAIS is the largest ice sheet on Earth, and poses a major hazard if it disappears.
Now a study in Nature suggests that 2°C of warming over “a couple of millennia” could cause significant melting of the EAIS.
“Antarctica is around twice the size of Australia, with ice sheets severalkilometerss thick and containing around half of the world’s fresh water,” said Dr Kevin Welsh, at the University of Queensland, a co-author on the study.
“The East Antarctic Ice Sheet covers about two thirds of the area, and because its base is largely above sea level it was generally thought to be less sensitive to warming climates than the adjacent West Antarctic Ice Sheet.
“However, some areas – like the Wilkes Land Subglacial Basin, directly south of Australia – are below sea level and contain enough ice to raise global sea levels by several meterss.
“The evidence we have suggests that with the predicted 2°C warming in Antarctica – if sustained over a couple of millennia – the sheet would start melting in these locations.”
Welsh’s team examined historic ice movements to effectively predict the future.
Glaciers, which are created by ice sheets, grind up rocks on land.
These rocks are then transported into the nearby Southern Ocean as sediment. This creates a record of earlier erosion by the ice sheet.
Researchers chemically analyzed layers of sediment from the ocean floor, which would have originated from the Wilkes Subglacial Basin – collected as part of the Integrated Ocean Drilling Program.
The study looked at sediment layers that had settled on the seafloor during the four warm intervals occurring between ice ages over the last 450,000 years.
“Studying ice sheet behavior in the geological past can inform us about future changes,” said Dr Wilson.
“By building a picture of how the ice sheet has grown and shrunk as temperatures have fluctuated, we can understand the response of the EAIS to future warming.”
The team found chemical “fingerprints” in the sediment which revealed the patterns of erosion as the ice sheet advanced and retreated.
It turned out that the ice sheet had retreated from its current size during some of these warmer “interglacial” periods, between 125,000 and 400,000 years ago.
Importantly, at the time, temperatures were as little as two degrees warmer than pre-industrial times – and one degree warmer than today.
During these warmer periods, global sea levels were between six and 13 meters higher than they are today.
According to researchers, if all the ice in the Wilkes Subglacial Basin melted in modern times, global sea levels would rise by up to four meters.
“We found that the most extreme changes in the ice sheet occurred during two interglacial periods 125,000 and 400,000 years ago, when global sea levels were several meters higher than they are today,” Dr Walsh explained.
“These periods could be analogues for future climates and it seems likely that ice loss from the East Antarctic Ice Sheet contributed to those higher sea levels.
“Ice loss contributes to rising global sea levels which are a threat to many coastal communities, and making projections requires a solid understanding of how sensitive these ice sheets are.”
One of the biggest concerns about rising sea levels is the risk than smaller, more common tsunamis could have a more damaging effect than they do today.
Last month, scientists issued a warning about the risk of “devastating tsunamis” caused by climate change.
Research in Science Advances suggested that rising sea levels – caused by global warming – significantly increase the threat of giant killer waves.
Experts modeled the impact of tsunamis based on sea level increases, and discovered worrying results.
It found that rising sea levels allowed tsunamis to reach much further inland, significantly increasing the risk of floods.
This means small tsunamis that might not be deadly today could wreak havoc in the future.
“Our research shows that sea-level rise can significantly increase the tsunami hazard, which means that smaller tsunamis in the future can have the same adverse impacts as big tsunamis would today,” said Robert Weiss, a professor of geosciences at Virginia Tech.
And if you think Britain is safe from tsunamis, think again.
Earlier this week, research revealed that deadly tsunamis crashing into the UK is more common than previously thought.
Scientists believe three killer waves have hit the UK within the last 10,000 years – raising the possibility that another one may be due.
We already knew about one of these: around 8,200 years ago, the Storegga submarine landslide off the coast of Norway sparked a 20-meter high tsunami that swept across Shetland.
Now experts have discovered evidence of two additional tsunamis that took place even more recently.
Researchers from Dundee University and the British Geological Survey found sands on Shetland that prove two separate tsunamis hit Britain in fairly recent history.
“We found sands aged 5,000 and 1,500 years old at multiple locations in Shetland, up to 13m above sea level,” said Dr. Sue Dawson, of the University of Dundee.
This story originally appeared in The Sun.