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(Marko Heuver)
A huge ice cap is likely to melt even if temperatures rise only 2 ° C, which could trigger a major climate chaos.
Scientists say that if the East Antarctic ice sheet – which is 60 times the size of England – melts, sea level could rise by four meters, which could cause regions to disappear completely. from the United Kingdom.
Experts now warn that more needs to be done to prevent global warming.
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Melting ice can have a devastating effect on the world, resulting in faster global warming, a change in ocean circulation systems that regulate global weather, and an increased risk of flooding and tsunami damage. .
A study on historical ice loss suggests that even a "moderate warming" of the Earth could melt the East Antarctic Ice Sheet.
"With current global temperatures already one step ahead of those of the pre-industrial period, future ice loss seems inevitable if we fail to reduce carbon emissions," said David Wilson of the United States. Imperial College London.
Scientists have put much effort into investigating the Western Antarctic ice sheet, which is mainly based on land below sea level.
Because of its low position, it is now contributing to most of the continent's melting ice.
But experts from Imperial College London and the University of Queensland have now studied the risks facing the East Antarctic icecap.
The EAIS is the largest ice cap on the planet and constitutes a major risk if it disappears.
A study in Nature suggests that 2 ° C warming over "a few millennia" could cause significant melting of the EAIS.
"The Antarctic is about twice the size of Australia, with thick layers of ice and about half of the world's freshwater," said Dr. Kevin Welsh, of the United States. University of Queensland.
"The eastern Antarctic ice cap covers about two-thirds of the area and, since its base is well above sea level, it was thought to be less sensitive to global warming than the adjacent western Antarctic ice cap.
"However, some areas – such as the Wilkes Land subglacial basin, directly south of Australia – are below sea level and contain enough ice to raise the global sea level by several meters.
"The evidence we have suggested that with the predicted warming of 2 ° C in Antarctica – if it is maintained for a few millennia – the leaf would begin to melt at these places."
The Welsh team has examined historical ice movements to effectively predict the future.
Glaciers, created by ice caps, crush rocks on the mainland.
These rocks are then transported to the nearby Southern Ocean as sediments. This creates an earlier erosion record by the ice cap.
The researchers chemically analyzed seabed sediments from the Wilkes Subglacial Basin – collected as part of the integrated ocean drilling program.
The study focused on sediment layers deposited on the seabed during the last four heat intervals between two ice ages over the past 450,000 years.
"The study of ice cap behavior in the geologic past can inform us of future changes," said Dr. Wilson.
"By drawing a picture of ice sheet growth and shrinkage as temperatures have fluctuated, we can understand the reaction of EAIS to future warming."
The team found chemical "footprints" in the sediments, which revealed the characteristics of erosion as the ice sheet moved forward 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.
It is important to note that at the time, temperatures were only two degrees warmer than the pre-industrial period – and a warmer degree than today.
During these warmer periods, the global level of the sea was between six and 13 meters higher than today.
According to the researchers, if all the ice in the subglacial Wilkes Basin melted in modern times, the sea level could rise by four meters.
"We found that the most extreme changes in the ice cap occurred during two interglacial periods 125,000 and 400,000 years ago, when the global level of the sea was several meters higher than today. hui, "said Dr. Walsh.
"These periods could be analogous for future climates and it seems likely that ice loss from the eastern Antarctic ice cap contributed to these higher sea levels.
"The loss of ice contributes to rising sea level globally, posing a threat to many coastal communities, and making projections requires a solid understanding of the sensitivity of these ice sheets."
One of the main concerns about sea level rise is the risk that smaller and more common tsunamis may have a more damaging effect than today.
Last month, scientists issued a warning about the risk of "devastating tsunamis" caused by climate change.
Research on scientific advances has shown that rising sea levels – caused by global warming – greatly increase the threat of giant waves.
Experts have modeled the impact of tsunamis on rising sea levels and found disturbing results.
He noted that sea-level rise allowed tsunamis to reach a greater extent inland, significantly increasing the risk of flooding.
This means that small tsunamis that might not be dead today could wreak havoc in the future.
"Our research shows that rising sea levels can dramatically increase tsunami risk, which means that small tsunamis in the future can have the same negative effects as big tsunamis today," Robert said. Weiss, professor of geosciences at Virginia Tech.
And if you think that Britain is safe from tsunamis, think again.
Earlier this week, research revealed that deadly tsunamis in the UK are more common than previously thought.
Scientists believe that three deadly waves have hit the United Kingdom in the last 10,000 years, suggesting that there may be another.
We already knew one: about 8,200 years ago, the Storegga submarine landslide off Norway triggered a 20-meter-high tsunami that swept the Shetlands.
Experts have now discovered evidence of two more tsunamis that have occurred even more recently.
Researchers from the University of Dundee and the British Geological Survey have discovered sands on the Shetland Islands, proving that two distinct tsunamis have struck Britain in recent history.
"We have found 5,000 and 1,500 year old sands at several locations in the Shetland, up to 13 m above sea level," said Dr. Sue Dawson, of Lt. University of Dundee.
This story originally appeared in The Sun.
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